/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp

Bug Summary

File:	clang/lib/Sema/SemaTemplateDeduction.cpp
Warning:	line 3666, column 31 Called C++ object pointer is null

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SemaTemplateDeduction.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2019-12-07-102640-14763-1 -x c++ /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp

/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp

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1//===- SemaTemplateDeduction.cpp - Template Argument Deduction ------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements C++ template argument deduction.
10//
11//===----------------------------------------------------------------------===//

13#include "clang/Sema/TemplateDeduction.h"
14#include "TreeTransform.h"
15#include "TypeLocBuilder.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/ASTLambda.h"
18#include "clang/AST/Decl.h"
19#include "clang/AST/DeclAccessPair.h"
20#include "clang/AST/DeclBase.h"
21#include "clang/AST/DeclCXX.h"
22#include "clang/AST/DeclTemplate.h"
23#include "clang/AST/DeclarationName.h"
24#include "clang/AST/Expr.h"
25#include "clang/AST/ExprCXX.h"
26#include "clang/AST/NestedNameSpecifier.h"
27#include "clang/AST/TemplateBase.h"
28#include "clang/AST/TemplateName.h"
29#include "clang/AST/Type.h"
30#include "clang/AST/TypeLoc.h"
31#include "clang/AST/UnresolvedSet.h"
32#include "clang/Basic/AddressSpaces.h"
33#include "clang/Basic/ExceptionSpecificationType.h"
34#include "clang/Basic/LLVM.h"
35#include "clang/Basic/LangOptions.h"
36#include "clang/Basic/PartialDiagnostic.h"
37#include "clang/Basic/SourceLocation.h"
38#include "clang/Basic/Specifiers.h"
39#include "clang/Sema/Ownership.h"
40#include "clang/Sema/Sema.h"
41#include "clang/Sema/Template.h"
42#include "llvm/ADT/APInt.h"
43#include "llvm/ADT/APSInt.h"
44#include "llvm/ADT/ArrayRef.h"
45#include "llvm/ADT/DenseMap.h"
46#include "llvm/ADT/FoldingSet.h"
47#include "llvm/ADT/Optional.h"
48#include "llvm/ADT/SmallBitVector.h"
49#include "llvm/ADT/SmallPtrSet.h"
50#include "llvm/ADT/SmallVector.h"
51#include "llvm/Support/Casting.h"
52#include "llvm/Support/Compiler.h"
53#include "llvm/Support/ErrorHandling.h"
54#include <algorithm>
55#include <cassert>
56#include <tuple>
57#include <utility>

59namespace clang {

/// Various flags that control template argument deduction.
///
/// These flags can be bitwise-OR'd together.
enum TemplateDeductionFlags {
  /// No template argument deduction flags, which indicates the
  /// strictest results for template argument deduction (as used for, e.g.,
  /// matching class template partial specializations).
  TDF_None = 0,

  /// Within template argument deduction from a function call, we are
  /// matching with a parameter type for which the original parameter was
  /// a reference.
  TDF_ParamWithReferenceType = 0x1,

  /// Within template argument deduction from a function call, we
  /// are matching in a case where we ignore cv-qualifiers.
  TDF_IgnoreQualifiers = 0x02,

  /// Within template argument deduction from a function call,
  /// we are matching in a case where we can perform template argument
  /// deduction from a template-id of a derived class of the argument type.
  TDF_DerivedClass = 0x04,

  /// Allow non-dependent types to differ, e.g., when performing
  /// template argument deduction from a function call where conversions
  /// may apply.
  TDF_SkipNonDependent = 0x08,

  /// Whether we are performing template argument deduction for
  /// parameters and arguments in a top-level template argument
  TDF_TopLevelParameterTypeList = 0x10,

  /// Within template argument deduction from overload resolution per
  /// C++ [over.over] allow matching function types that are compatible in
  /// terms of noreturn and default calling convention adjustments, or
  /// similarly matching a declared template specialization against a
  /// possible template, per C++ [temp.deduct.decl]. In either case, permit
  /// deduction where the parameter is a function type that can be converted
  /// to the argument type.
  TDF_AllowCompatibleFunctionType = 0x20,

  /// Within template argument deduction for a conversion function, we are
  /// matching with an argument type for which the original argument was
  /// a reference.
  TDF_ArgWithReferenceType = 0x40,
};
107}

109using namespace clang;
110using namespace sema;

112/// Compare two APSInts, extending and switching the sign as
113/// necessary to compare their values regardless of underlying type.
114static bool hasSameExtendedValue(llvm::APSInt X, llvm::APSInt Y) {
if (Y.getBitWidth() > X.getBitWidth())
  X = X.extend(Y.getBitWidth());
else if (Y.getBitWidth() < X.getBitWidth())
  Y = Y.extend(X.getBitWidth());

// If there is a signedness mismatch, correct it.
if (X.isSigned() != Y.isSigned()) {
  // If the signed value is negative, then the values cannot be the same.
  if ((Y.isSigned() && Y.isNegative()) || (X.isSigned() && X.isNegative()))
    return false;

  Y.setIsSigned(true);
  X.setIsSigned(true);
}

return X == Y;
131}

133static Sema::TemplateDeductionResult
134DeduceTemplateArguments(Sema &S,
                      TemplateParameterList *TemplateParams,
                      const TemplateArgument &Param,
                      TemplateArgument Arg,
                      TemplateDeductionInfo &Info,
                      SmallVectorImpl<DeducedTemplateArgument> &Deduced);

141static Sema::TemplateDeductionResult
142DeduceTemplateArgumentsByTypeMatch(Sema &S,
                                 TemplateParameterList *TemplateParams,
                                 QualType Param,
                                 QualType Arg,
                                 TemplateDeductionInfo &Info,
                                 SmallVectorImpl<DeducedTemplateArgument> &
                                                    Deduced,
                                 unsigned TDF,
                                 bool PartialOrdering = false,
                                 bool DeducedFromArrayBound = false);

153static Sema::TemplateDeductionResult
154DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams,
                      ArrayRef<TemplateArgument> Params,
                      ArrayRef<TemplateArgument> Args,
                      TemplateDeductionInfo &Info,
                      SmallVectorImpl<DeducedTemplateArgument> &Deduced,
                      bool NumberOfArgumentsMustMatch);

161static void MarkUsedTemplateParameters(ASTContext &Ctx,
                                     const TemplateArgument &TemplateArg,
                                     bool OnlyDeduced, unsigned Depth,
                                     llvm::SmallBitVector &Used);

166static void MarkUsedTemplateParameters(ASTContext &Ctx, QualType T,
                                     bool OnlyDeduced, unsigned Level,
                                     llvm::SmallBitVector &Deduced);

170/// If the given expression is of a form that permits the deduction
171/// of a non-type template parameter, return the declaration of that
172/// non-type template parameter.
173static NonTypeTemplateParmDecl *
174getDeducedParameterFromExpr(TemplateDeductionInfo &Info, Expr *E) {
// If we are within an alias template, the expression may have undergone
// any number of parameter substitutions already.
while (true) {
  if (ImplicitCastExpr *IC = dyn_cast<ImplicitCastExpr>(E))
    E = IC->getSubExpr();
  else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(E))
    E = CE->getSubExpr();
  else if (SubstNonTypeTemplateParmExpr *Subst =
             dyn_cast<SubstNonTypeTemplateParmExpr>(E))
    E = Subst->getReplacement();
  else
    break;
}

if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
  if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl()))
    if (NTTP->getDepth() == Info.getDeducedDepth())
      return NTTP;

return nullptr;
195}

197/// Determine whether two declaration pointers refer to the same
198/// declaration.
199static bool isSameDeclaration(Decl *X, Decl *Y) {
if (NamedDecl *NX = dyn_cast<NamedDecl>(X))
  X = NX->getUnderlyingDecl();
if (NamedDecl *NY = dyn_cast<NamedDecl>(Y))
  Y = NY->getUnderlyingDecl();

return X->getCanonicalDecl() == Y->getCanonicalDecl();
206}

208/// Verify that the given, deduced template arguments are compatible.
209///
210/// \returns The deduced template argument, or a NULL template argument if
211/// the deduced template arguments were incompatible.
212static DeducedTemplateArgument
213checkDeducedTemplateArguments(ASTContext &Context,
                            const DeducedTemplateArgument &X,
                            const DeducedTemplateArgument &Y) {
// We have no deduction for one or both of the arguments; they're compatible.
if (X.isNull())
  return Y;
if (Y.isNull())
  return X;

// If we have two non-type template argument values deduced for the same
// parameter, they must both match the type of the parameter, and thus must
// match each other's type. As we're only keeping one of them, we must check
// for that now. The exception is that if either was deduced from an array
// bound, the type is permitted to differ.
if (!X.wasDeducedFromArrayBound() && !Y.wasDeducedFromArrayBound()) {
  QualType XType = X.getNonTypeTemplateArgumentType();
  if (!XType.isNull()) {
    QualType YType = Y.getNonTypeTemplateArgumentType();
    if (YType.isNull() || !Context.hasSameType(XType, YType))
      return DeducedTemplateArgument();
  }
}

switch (X.getKind()) {
case TemplateArgument::Null:
  llvm_unreachable("Non-deduced template arguments handled above")::llvm::llvm_unreachable_internal("Non-deduced template arguments handled above"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 238);

case TemplateArgument::Type:
  // If two template type arguments have the same type, they're compatible.
  if (Y.getKind() == TemplateArgument::Type &&
      Context.hasSameType(X.getAsType(), Y.getAsType()))
    return X;

  // If one of the two arguments was deduced from an array bound, the other
  // supersedes it.
  if (X.wasDeducedFromArrayBound() != Y.wasDeducedFromArrayBound())
    return X.wasDeducedFromArrayBound() ? Y : X;

  // The arguments are not compatible.
  return DeducedTemplateArgument();

case TemplateArgument::Integral:
  // If we deduced a constant in one case and either a dependent expression or
  // declaration in another case, keep the integral constant.
  // If both are integral constants with the same value, keep that value.
  if (Y.getKind() == TemplateArgument::Expression ||
      Y.getKind() == TemplateArgument::Declaration ||
      (Y.getKind() == TemplateArgument::Integral &&
       hasSameExtendedValue(X.getAsIntegral(), Y.getAsIntegral())))
    return X.wasDeducedFromArrayBound() ? Y : X;

  // All other combinations are incompatible.
  return DeducedTemplateArgument();

case TemplateArgument::Template:
  if (Y.getKind() == TemplateArgument::Template &&
      Context.hasSameTemplateName(X.getAsTemplate(), Y.getAsTemplate()))
    return X;

  // All other combinations are incompatible.
  return DeducedTemplateArgument();

case TemplateArgument::TemplateExpansion:
  if (Y.getKind() == TemplateArgument::TemplateExpansion &&
      Context.hasSameTemplateName(X.getAsTemplateOrTemplatePattern(),
                                  Y.getAsTemplateOrTemplatePattern()))
    return X;

  // All other combinations are incompatible.
  return DeducedTemplateArgument();

case TemplateArgument::Expression: {
  if (Y.getKind() != TemplateArgument::Expression)
    return checkDeducedTemplateArguments(Context, Y, X);

  // Compare the expressions for equality
  llvm::FoldingSetNodeID ID1, ID2;
  X.getAsExpr()->Profile(ID1, Context, true);
  Y.getAsExpr()->Profile(ID2, Context, true);
  if (ID1 == ID2)
    return X.wasDeducedFromArrayBound() ? Y : X;

  // Differing dependent expressions are incompatible.
  return DeducedTemplateArgument();
}

case TemplateArgument::Declaration:
  assert(!X.wasDeducedFromArrayBound())((!X.wasDeducedFromArrayBound()) ? static_cast<void> (0
) : __assert_fail ("!X.wasDeducedFromArrayBound()", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 300, __PRETTY_FUNCTION__));

  // If we deduced a declaration and a dependent expression, keep the
  // declaration.
  if (Y.getKind() == TemplateArgument::Expression)
    return X;

  // If we deduced a declaration and an integral constant, keep the
  // integral constant and whichever type did not come from an array
  // bound.
  if (Y.getKind() == TemplateArgument::Integral) {
    if (Y.wasDeducedFromArrayBound())
      return TemplateArgument(Context, Y.getAsIntegral(),
                              X.getParamTypeForDecl());
    return Y;
  }

  // If we deduced two declarations, make sure that they refer to the
  // same declaration.
  if (Y.getKind() == TemplateArgument::Declaration &&
      isSameDeclaration(X.getAsDecl(), Y.getAsDecl()))
    return X;

  // All other combinations are incompatible.
  return DeducedTemplateArgument();

case TemplateArgument::NullPtr:
  // If we deduced a null pointer and a dependent expression, keep the
  // null pointer.
  if (Y.getKind() == TemplateArgument::Expression)
    return X;

  // If we deduced a null pointer and an integral constant, keep the
  // integral constant.
  if (Y.getKind() == TemplateArgument::Integral)
    return Y;

  // If we deduced two null pointers, they are the same.
  if (Y.getKind() == TemplateArgument::NullPtr)
    return X;

  // All other combinations are incompatible.
  return DeducedTemplateArgument();

case TemplateArgument::Pack: {
  if (Y.getKind() != TemplateArgument::Pack ||
      X.pack_size() != Y.pack_size())
    return DeducedTemplateArgument();

  llvm::SmallVector<TemplateArgument, 8> NewPack;
  for (TemplateArgument::pack_iterator XA = X.pack_begin(),
                                    XAEnd = X.pack_end(),
                                       YA = Y.pack_begin();
       XA != XAEnd; ++XA, ++YA) {
    TemplateArgument Merged = checkDeducedTemplateArguments(
        Context, DeducedTemplateArgument(*XA, X.wasDeducedFromArrayBound()),
        DeducedTemplateArgument(*YA, Y.wasDeducedFromArrayBound()));
    if (Merged.isNull())
      return DeducedTemplateArgument();
    NewPack.push_back(Merged);
  }

  return DeducedTemplateArgument(
      TemplateArgument::CreatePackCopy(Context, NewPack),
      X.wasDeducedFromArrayBound() && Y.wasDeducedFromArrayBound());
}
}

llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 368);
369}

371/// Deduce the value of the given non-type template parameter
372/// as the given deduced template argument. All non-type template parameter
373/// deduction is funneled through here.
374static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
  Sema &S, TemplateParameterList *TemplateParams,
  NonTypeTemplateParmDecl *NTTP, const DeducedTemplateArgument &NewDeduced,
  QualType ValueType, TemplateDeductionInfo &Info,
  SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
assert(NTTP->getDepth() == Info.getDeducedDepth() &&((NTTP->getDepth() == Info.getDeducedDepth() && "deducing non-type template argument with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"deducing non-type template argument with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 380, __PRETTY_FUNCTION__))
       "deducing non-type template argument with wrong depth")((NTTP->getDepth() == Info.getDeducedDepth() && "deducing non-type template argument with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"deducing non-type template argument with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 380, __PRETTY_FUNCTION__));

DeducedTemplateArgument Result = checkDeducedTemplateArguments(
    S.Context, Deduced[NTTP->getIndex()], NewDeduced);
if (Result.isNull()) {
  Info.Param = NTTP;
  Info.FirstArg = Deduced[NTTP->getIndex()];
  Info.SecondArg = NewDeduced;
  return Sema::TDK_Inconsistent;
}

Deduced[NTTP->getIndex()] = Result;
if (!S.getLangOpts().CPlusPlus17)
  return Sema::TDK_Success;

if (NTTP->isExpandedParameterPack())
  // FIXME: We may still need to deduce parts of the type here! But we
  // don't have any way to find which slice of the type to use, and the
  // type stored on the NTTP itself is nonsense. Perhaps the type of an
  // expanded NTTP should be a pack expansion type?
  return Sema::TDK_Success;

// Get the type of the parameter for deduction. If it's a (dependent) array
// or function type, we will not have decayed it yet, so do that now.
QualType ParamType = S.Context.getAdjustedParameterType(NTTP->getType());
if (auto *Expansion = dyn_cast<PackExpansionType>(ParamType))
  ParamType = Expansion->getPattern();

// FIXME: It's not clear how deduction of a parameter of reference
// type from an argument (of non-reference type) should be performed.
// For now, we just remove reference types from both sides and let
// the final check for matching types sort out the mess.
return DeduceTemplateArgumentsByTypeMatch(
    S, TemplateParams, ParamType.getNonReferenceType(),
    ValueType.getNonReferenceType(), Info, Deduced, TDF_SkipNonDependent,
    /*PartialOrdering=*/false,
    /*ArrayBound=*/NewDeduced.wasDeducedFromArrayBound());
417}

419/// Deduce the value of the given non-type template parameter
420/// from the given integral constant.
421static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
  Sema &S, TemplateParameterList *TemplateParams,
  NonTypeTemplateParmDecl *NTTP, const llvm::APSInt &Value,
  QualType ValueType, bool DeducedFromArrayBound, TemplateDeductionInfo &Info,
  SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
return DeduceNonTypeTemplateArgument(
    S, TemplateParams, NTTP,
    DeducedTemplateArgument(S.Context, Value, ValueType,
                            DeducedFromArrayBound),
    ValueType, Info, Deduced);
431}

433/// Deduce the value of the given non-type template parameter
434/// from the given null pointer template argument type.
435static Sema::TemplateDeductionResult DeduceNullPtrTemplateArgument(
  Sema &S, TemplateParameterList *TemplateParams,
  NonTypeTemplateParmDecl *NTTP, QualType NullPtrType,
  TemplateDeductionInfo &Info,
  SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
Expr *Value =
    S.ImpCastExprToType(new (S.Context) CXXNullPtrLiteralExpr(
                            S.Context.NullPtrTy, NTTP->getLocation()),
                        NullPtrType, CK_NullToPointer)
        .get();
return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
                                     DeducedTemplateArgument(Value),
                                     Value->getType(), Info, Deduced);
448}

450/// Deduce the value of the given non-type template parameter
451/// from the given type- or value-dependent expression.
452///
453/// \returns true if deduction succeeded, false otherwise.
454static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
  Sema &S, TemplateParameterList *TemplateParams,
  NonTypeTemplateParmDecl *NTTP, Expr *Value, TemplateDeductionInfo &Info,
  SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
                                     DeducedTemplateArgument(Value),
                                     Value->getType(), Info, Deduced);
461}

463/// Deduce the value of the given non-type template parameter
464/// from the given declaration.
465///
466/// \returns true if deduction succeeded, false otherwise.
467static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
  Sema &S, TemplateParameterList *TemplateParams,
  NonTypeTemplateParmDecl *NTTP, ValueDecl *D, QualType T,
  TemplateDeductionInfo &Info,
  SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
D = D ? cast<ValueDecl>(D->getCanonicalDecl()) : nullptr;
TemplateArgument New(D, T);
return DeduceNonTypeTemplateArgument(
    S, TemplateParams, NTTP, DeducedTemplateArgument(New), T, Info, Deduced);
476}

478static Sema::TemplateDeductionResult
479DeduceTemplateArguments(Sema &S,
                      TemplateParameterList *TemplateParams,
                      TemplateName Param,
                      TemplateName Arg,
                      TemplateDeductionInfo &Info,
                      SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
TemplateDecl *ParamDecl = Param.getAsTemplateDecl();
if (!ParamDecl) {
  // The parameter type is dependent and is not a template template parameter,
  // so there is nothing that we can deduce.
  return Sema::TDK_Success;
}

if (TemplateTemplateParmDecl *TempParam
      = dyn_cast<TemplateTemplateParmDecl>(ParamDecl)) {
  // If we're not deducing at this depth, there's nothing to deduce.
  if (TempParam->getDepth() != Info.getDeducedDepth())
    return Sema::TDK_Success;

  DeducedTemplateArgument NewDeduced(S.Context.getCanonicalTemplateName(Arg));
  DeducedTemplateArgument Result = checkDeducedTemplateArguments(S.Context,
                                               Deduced[TempParam->getIndex()],
                                                                 NewDeduced);
  if (Result.isNull()) {
    Info.Param = TempParam;
    Info.FirstArg = Deduced[TempParam->getIndex()];
    Info.SecondArg = NewDeduced;
    return Sema::TDK_Inconsistent;
  }

  Deduced[TempParam->getIndex()] = Result;
  return Sema::TDK_Success;
}

// Verify that the two template names are equivalent.
if (S.Context.hasSameTemplateName(Param, Arg))
  return Sema::TDK_Success;

// Mismatch of non-dependent template parameter to argument.
Info.FirstArg = TemplateArgument(Param);
Info.SecondArg = TemplateArgument(Arg);
return Sema::TDK_NonDeducedMismatch;
521}

523/// Deduce the template arguments by comparing the template parameter
524/// type (which is a template-id) with the template argument type.
525///
526/// \param S the Sema
527///
528/// \param TemplateParams the template parameters that we are deducing
529///
530/// \param Param the parameter type
531///
532/// \param Arg the argument type
533///
534/// \param Info information about the template argument deduction itself
535///
536/// \param Deduced the deduced template arguments
537///
538/// \returns the result of template argument deduction so far. Note that a
539/// "success" result means that template argument deduction has not yet failed,
540/// but it may still fail, later, for other reasons.
541static Sema::TemplateDeductionResult
542DeduceTemplateArguments(Sema &S,
                      TemplateParameterList *TemplateParams,
                      const TemplateSpecializationType *Param,
                      QualType Arg,
                      TemplateDeductionInfo &Info,
                      SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
assert(Arg.isCanonical() && "Argument type must be canonical")((Arg.isCanonical() && "Argument type must be canonical"
) ? static_cast<void> (0) : __assert_fail ("Arg.isCanonical() && \"Argument type must be canonical\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 548, __PRETTY_FUNCTION__));

// Treat an injected-class-name as its underlying template-id.
if (auto *Injected = dyn_cast<InjectedClassNameType>(Arg))
  Arg = Injected->getInjectedSpecializationType();

// Check whether the template argument is a dependent template-id.
if (const TemplateSpecializationType *SpecArg
      = dyn_cast<TemplateSpecializationType>(Arg)) {
  // Perform template argument deduction for the template name.
  if (Sema::TemplateDeductionResult Result
        = DeduceTemplateArguments(S, TemplateParams,
                                  Param->getTemplateName(),
                                  SpecArg->getTemplateName(),
                                  Info, Deduced))
    return Result;


  // Perform template argument deduction on each template
  // argument. Ignore any missing/extra arguments, since they could be
  // filled in by default arguments.
  return DeduceTemplateArguments(S, TemplateParams,
                                 Param->template_arguments(),
                                 SpecArg->template_arguments(), Info, Deduced,
                                 /*NumberOfArgumentsMustMatch=*/false);
}

// If the argument type is a class template specialization, we
// perform template argument deduction using its template
// arguments.
const RecordType *RecordArg = dyn_cast<RecordType>(Arg);
if (!RecordArg) {
  Info.FirstArg = TemplateArgument(QualType(Param, 0));
  Info.SecondArg = TemplateArgument(Arg);
  return Sema::TDK_NonDeducedMismatch;
}

ClassTemplateSpecializationDecl *SpecArg
  = dyn_cast<ClassTemplateSpecializationDecl>(RecordArg->getDecl());
if (!SpecArg) {
  Info.FirstArg = TemplateArgument(QualType(Param, 0));
  Info.SecondArg = TemplateArgument(Arg);
  return Sema::TDK_NonDeducedMismatch;
}

// Perform template argument deduction for the template name.
if (Sema::TemplateDeductionResult Result
      = DeduceTemplateArguments(S,
                                TemplateParams,
                                Param->getTemplateName(),
                             TemplateName(SpecArg->getSpecializedTemplate()),
                                Info, Deduced))
  return Result;

// Perform template argument deduction for the template arguments.
return DeduceTemplateArguments(S, TemplateParams, Param->template_arguments(),
                               SpecArg->getTemplateArgs().asArray(), Info,
                               Deduced, /*NumberOfArgumentsMustMatch=*/true);
606}

608/// Determines whether the given type is an opaque type that
609/// might be more qualified when instantiated.
610static bool IsPossiblyOpaquelyQualifiedType(QualType T) {
switch (T->getTypeClass()) {
case Type::TypeOfExpr:
case Type::TypeOf:
case Type::DependentName:
case Type::Decltype:
case Type::UnresolvedUsing:
case Type::TemplateTypeParm:
  return true;

case Type::ConstantArray:
case Type::IncompleteArray:
case Type::VariableArray:
case Type::DependentSizedArray:
  return IsPossiblyOpaquelyQualifiedType(
                                    cast<ArrayType>(T)->getElementType());

default:
  return false;
}
630}

632/// Helper function to build a TemplateParameter when we don't
633/// know its type statically.
634static TemplateParameter makeTemplateParameter(Decl *D) {
if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(D))
  return TemplateParameter(TTP);
if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D))
  return TemplateParameter(NTTP);

return TemplateParameter(cast<TemplateTemplateParmDecl>(D));
641}

643/// If \p Param is an expanded parameter pack, get the number of expansions.
644static Optional<unsigned> getExpandedPackSize(NamedDecl *Param) {
if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Param))
  if (NTTP->isExpandedParameterPack())
    return NTTP->getNumExpansionTypes();

if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Param))
  if (TTP->isExpandedParameterPack())
    return TTP->getNumExpansionTemplateParameters();

return None;
654}

656/// A pack that we're currently deducing.
657struct clang::DeducedPack {
// The index of the pack.
unsigned Index;

// The old value of the pack before we started deducing it.
DeducedTemplateArgument Saved;

// A deferred value of this pack from an inner deduction, that couldn't be
// deduced because this deduction hadn't happened yet.
DeducedTemplateArgument DeferredDeduction;

// The new value of the pack.
SmallVector<DeducedTemplateArgument, 4> New;

// The outer deduction for this pack, if any.
DeducedPack *Outer = nullptr;

DeducedPack(unsigned Index) : Index(Index) {}
675};

677namespace {

679/// A scope in which we're performing pack deduction.
680class PackDeductionScope {
681public:
/// Prepare to deduce the packs named within Pattern.
PackDeductionScope(Sema &S, TemplateParameterList *TemplateParams,
                   SmallVectorImpl<DeducedTemplateArgument> &Deduced,
                   TemplateDeductionInfo &Info, TemplateArgument Pattern)
    : S(S), TemplateParams(TemplateParams), Deduced(Deduced), Info(Info) {
  unsigned NumNamedPacks = addPacks(Pattern);
  finishConstruction(NumNamedPacks);
}

/// Prepare to directly deduce arguments of the parameter with index \p Index.
PackDeductionScope(Sema &S, TemplateParameterList *TemplateParams,
                   SmallVectorImpl<DeducedTemplateArgument> &Deduced,
                   TemplateDeductionInfo &Info, unsigned Index)
    : S(S), TemplateParams(TemplateParams), Deduced(Deduced), Info(Info) {
  addPack(Index);
  finishConstruction(1);
}

700private:
void addPack(unsigned Index) {
  // Save the deduced template argument for the parameter pack expanded
  // by this pack expansion, then clear out the deduction.
  DeducedPack Pack(Index);
  Pack.Saved = Deduced[Index];
  Deduced[Index] = TemplateArgument();

  // FIXME: What if we encounter multiple packs with different numbers of
  // pre-expanded expansions? (This should already have been diagnosed
  // during substitution.)
  if (Optional<unsigned> ExpandedPackExpansions =
          getExpandedPackSize(TemplateParams->getParam(Index)))
    FixedNumExpansions = ExpandedPackExpansions;

  Packs.push_back(Pack);
}

unsigned addPacks(TemplateArgument Pattern) {
  // Compute the set of template parameter indices that correspond to
  // parameter packs expanded by the pack expansion.
  llvm::SmallBitVector SawIndices(TemplateParams->size());

  auto AddPack = [&](unsigned Index) {
    if (SawIndices[Index])
      return;
    SawIndices[Index] = true;
    addPack(Index);
  };

  // First look for unexpanded packs in the pattern.
  SmallVector<UnexpandedParameterPack, 2> Unexpanded;
  S.collectUnexpandedParameterPacks(Pattern, Unexpanded);
  for (unsigned I = 0, N = Unexpanded.size(); I != N; ++I) {
    unsigned Depth, Index;
    std::tie(Depth, Index) = getDepthAndIndex(Unexpanded[I]);
    if (Depth == Info.getDeducedDepth())
      AddPack(Index);
  }
  assert(!Packs.empty() && "Pack expansion without unexpanded packs?")((!Packs.empty() && "Pack expansion without unexpanded packs?"
) ? static_cast<void> (0) : __assert_fail ("!Packs.empty() && \"Pack expansion without unexpanded packs?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 739, __PRETTY_FUNCTION__));

  unsigned NumNamedPacks = Packs.size();

  // We can also have deduced template parameters that do not actually
  // appear in the pattern, but can be deduced by it (the type of a non-type
  // template parameter pack, in particular). These won't have prevented us
  // from partially expanding the pack.
  llvm::SmallBitVector Used(TemplateParams->size());
  MarkUsedTemplateParameters(S.Context, Pattern, /*OnlyDeduced*/true,
                             Info.getDeducedDepth(), Used);
  for (int Index = Used.find_first(); Index != -1;
       Index = Used.find_next(Index))
    if (TemplateParams->getParam(Index)->isParameterPack())
      AddPack(Index);

  return NumNamedPacks;
}

void finishConstruction(unsigned NumNamedPacks) {
  // Dig out the partially-substituted pack, if there is one.
  const TemplateArgument *PartialPackArgs = nullptr;
  unsigned NumPartialPackArgs = 0;
  std::pair<unsigned, unsigned> PartialPackDepthIndex(-1u, -1u);
  if (auto *Scope = S.CurrentInstantiationScope)
    if (auto *Partial = Scope->getPartiallySubstitutedPack(
            &PartialPackArgs, &NumPartialPackArgs))
      PartialPackDepthIndex = getDepthAndIndex(Partial);

  // This pack expansion will have been partially or fully expanded if
  // it only names explicitly-specified parameter packs (including the
  // partially-substituted one, if any).
  bool IsExpanded = true;
  for (unsigned I = 0; I != NumNamedPacks; ++I) {
    if (Packs[I].Index >= Info.getNumExplicitArgs()) {
      IsExpanded = false;
      IsPartiallyExpanded = false;
      break;
    }
    if (PartialPackDepthIndex ==
          std::make_pair(Info.getDeducedDepth(), Packs[I].Index)) {
      IsPartiallyExpanded = true;
    }
  }

  // Skip over the pack elements that were expanded into separate arguments.
  // If we partially expanded, this is the number of partial arguments.
  if (IsPartiallyExpanded)
    PackElements += NumPartialPackArgs;
  else if (IsExpanded)
    PackElements += *FixedNumExpansions;

  for (auto &Pack : Packs) {
    if (Info.PendingDeducedPacks.size() > Pack.Index)
      Pack.Outer = Info.PendingDeducedPacks[Pack.Index];
    else
      Info.PendingDeducedPacks.resize(Pack.Index + 1);
    Info.PendingDeducedPacks[Pack.Index] = &Pack;

    if (PartialPackDepthIndex ==
          std::make_pair(Info.getDeducedDepth(), Pack.Index)) {
      Pack.New.append(PartialPackArgs, PartialPackArgs + NumPartialPackArgs);
      // We pre-populate the deduced value of the partially-substituted
      // pack with the specified value. This is not entirely correct: the
      // value is supposed to have been substituted, not deduced, but the
      // cases where this is observable require an exact type match anyway.
      //
      // FIXME: If we could represent a "depth i, index j, pack elem k"
      // parameter, we could substitute the partially-substituted pack
      // everywhere and avoid this.
      if (!IsPartiallyExpanded)
        Deduced[Pack.Index] = Pack.New[PackElements];
    }
  }
}

815public:
~PackDeductionScope() {
  for (auto &Pack : Packs)
    Info.PendingDeducedPacks[Pack.Index] = Pack.Outer;
}

/// Determine whether this pack has already been partially expanded into a
/// sequence of (prior) function parameters / template arguments.
bool isPartiallyExpanded() { return IsPartiallyExpanded; }

/// Determine whether this pack expansion scope has a known, fixed arity.
/// This happens if it involves a pack from an outer template that has
/// (notionally) already been expanded.
bool hasFixedArity() { return FixedNumExpansions.hasValue(); }

/// Determine whether the next element of the argument is still part of this
/// pack. This is the case unless the pack is already expanded to a fixed
/// length.
bool hasNextElement() {
  return !FixedNumExpansions || *FixedNumExpansions > PackElements;
}

/// Move to deducing the next element in each pack that is being deduced.
void nextPackElement() {
  // Capture the deduced template arguments for each parameter pack expanded
  // by this pack expansion, add them to the list of arguments we've deduced
  // for that pack, then clear out the deduced argument.
  for (auto &Pack : Packs) {
    DeducedTemplateArgument &DeducedArg = Deduced[Pack.Index];
    if (!Pack.New.empty() || !DeducedArg.isNull()) {
      while (Pack.New.size() < PackElements)
        Pack.New.push_back(DeducedTemplateArgument());
      if (Pack.New.size() == PackElements)
        Pack.New.push_back(DeducedArg);
      else
        Pack.New[PackElements] = DeducedArg;
      DeducedArg = Pack.New.size() > PackElements + 1
                       ? Pack.New[PackElements + 1]
                       : DeducedTemplateArgument();
    }
  }
  ++PackElements;
}

/// Finish template argument deduction for a set of argument packs,
/// producing the argument packs and checking for consistency with prior
/// deductions.
Sema::TemplateDeductionResult
finish(bool TreatNoDeductionsAsNonDeduced = true) {
  // Build argument packs for each of the parameter packs expanded by this
  // pack expansion.
  for (auto &Pack : Packs) {
    // Put back the old value for this pack.
    Deduced[Pack.Index] = Pack.Saved;

    // If we are deducing the size of this pack even if we didn't deduce any
    // values for it, then make sure we build a pack of the right size.
    // FIXME: Should we always deduce the size, even if the pack appears in
    // a non-deduced context?
    if (!TreatNoDeductionsAsNonDeduced)
      Pack.New.resize(PackElements);

    // Build or find a new value for this pack.
    DeducedTemplateArgument NewPack;
    if (PackElements && Pack.New.empty()) {
      if (Pack.DeferredDeduction.isNull()) {
        // We were not able to deduce anything for this parameter pack
        // (because it only appeared in non-deduced contexts), so just
        // restore the saved argument pack.
        continue;
      }

      NewPack = Pack.DeferredDeduction;
      Pack.DeferredDeduction = TemplateArgument();
    } else if (Pack.New.empty()) {
      // If we deduced an empty argument pack, create it now.
      NewPack = DeducedTemplateArgument(TemplateArgument::getEmptyPack());
    } else {
      TemplateArgument *ArgumentPack =
          new (S.Context) TemplateArgument[Pack.New.size()];
      std::copy(Pack.New.begin(), Pack.New.end(), ArgumentPack);
      NewPack = DeducedTemplateArgument(
          TemplateArgument(llvm::makeArrayRef(ArgumentPack, Pack.New.size())),
          // FIXME: This is wrong, it's possible that some pack elements are
          // deduced from an array bound and others are not:
          //   template<typename ...T, T ...V> void g(const T (&...p)[V]);
          //   g({1, 2, 3}, {{}, {}});
          // ... should deduce T = {int, size_t (from array bound)}.
          Pack.New[0].wasDeducedFromArrayBound());
    }

    // Pick where we're going to put the merged pack.
    DeducedTemplateArgument *Loc;
    if (Pack.Outer) {
      if (Pack.Outer->DeferredDeduction.isNull()) {
        // Defer checking this pack until we have a complete pack to compare
        // it against.
        Pack.Outer->DeferredDeduction = NewPack;
        continue;
      }
      Loc = &Pack.Outer->DeferredDeduction;
    } else {
      Loc = &Deduced[Pack.Index];
    }

    // Check the new pack matches any previous value.
    DeducedTemplateArgument OldPack = *Loc;
    DeducedTemplateArgument Result =
        checkDeducedTemplateArguments(S.Context, OldPack, NewPack);

    // If we deferred a deduction of this pack, check that one now too.
    if (!Result.isNull() && !Pack.DeferredDeduction.isNull()) {
      OldPack = Result;
      NewPack = Pack.DeferredDeduction;
      Result = checkDeducedTemplateArguments(S.Context, OldPack, NewPack);
    }

    NamedDecl *Param = TemplateParams->getParam(Pack.Index);
    if (Result.isNull()) {
      Info.Param = makeTemplateParameter(Param);
      Info.FirstArg = OldPack;
      Info.SecondArg = NewPack;
      return Sema::TDK_Inconsistent;
    }

    // If we have a pre-expanded pack and we didn't deduce enough elements
    // for it, fail deduction.
    if (Optional<unsigned> Expansions = getExpandedPackSize(Param)) {
      if (*Expansions != PackElements) {
        Info.Param = makeTemplateParameter(Param);
        Info.FirstArg = Result;
        return Sema::TDK_IncompletePack;
      }
    }

    *Loc = Result;
  }

  return Sema::TDK_Success;
}

956private:
Sema &S;
TemplateParameterList *TemplateParams;
SmallVectorImpl<DeducedTemplateArgument> &Deduced;
TemplateDeductionInfo &Info;
unsigned PackElements = 0;
bool IsPartiallyExpanded = false;
/// The number of expansions, if we have a fully-expanded pack in this scope.
Optional<unsigned> FixedNumExpansions;

SmallVector<DeducedPack, 2> Packs;
967};

969} // namespace

971/// Deduce the template arguments by comparing the list of parameter
972/// types to the list of argument types, as in the parameter-type-lists of
973/// function types (C++ [temp.deduct.type]p10).
974///
975/// \param S The semantic analysis object within which we are deducing
976///
977/// \param TemplateParams The template parameters that we are deducing
978///
979/// \param Params The list of parameter types
980///
981/// \param NumParams The number of types in \c Params
982///
983/// \param Args The list of argument types
984///
985/// \param NumArgs The number of types in \c Args
986///
987/// \param Info information about the template argument deduction itself
988///
989/// \param Deduced the deduced template arguments
990///
991/// \param TDF bitwise OR of the TemplateDeductionFlags bits that describe
992/// how template argument deduction is performed.
993///
994/// \param PartialOrdering If true, we are performing template argument
995/// deduction for during partial ordering for a call
996/// (C++0x [temp.deduct.partial]).
997///
998/// \returns the result of template argument deduction so far. Note that a
999/// "success" result means that template argument deduction has not yet failed,
1000/// but it may still fail, later, for other reasons.
1001static Sema::TemplateDeductionResult
1002DeduceTemplateArguments(Sema &S,
                      TemplateParameterList *TemplateParams,
                      const QualType *Params, unsigned NumParams,
                      const QualType *Args, unsigned NumArgs,
                      TemplateDeductionInfo &Info,
                      SmallVectorImpl<DeducedTemplateArgument> &Deduced,
                      unsigned TDF,
                      bool PartialOrdering = false) {
// C++0x [temp.deduct.type]p10:
//   Similarly, if P has a form that contains (T), then each parameter type
//   Pi of the respective parameter-type- list of P is compared with the
//   corresponding parameter type Ai of the corresponding parameter-type-list
//   of A. [...]
unsigned ArgIdx = 0, ParamIdx = 0;
for (; ParamIdx != NumParams; ++ParamIdx) {
  // Check argument types.
  const PackExpansionType *Expansion
                              = dyn_cast<PackExpansionType>(Params[ParamIdx]);
  if (!Expansion) {
    // Simple case: compare the parameter and argument types at this point.

    // Make sure we have an argument.
    if (ArgIdx >= NumArgs)
      return Sema::TDK_MiscellaneousDeductionFailure;

    if (isa<PackExpansionType>(Args[ArgIdx])) {
      // C++0x [temp.deduct.type]p22:
      //   If the original function parameter associated with A is a function
      //   parameter pack and the function parameter associated with P is not
      //   a function parameter pack, then template argument deduction fails.
      return Sema::TDK_MiscellaneousDeductionFailure;
    }

    if (Sema::TemplateDeductionResult Result
          = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                               Params[ParamIdx], Args[ArgIdx],
                                               Info, Deduced, TDF,
                                               PartialOrdering))
      return Result;

    ++ArgIdx;
    continue;
  }

  // C++0x [temp.deduct.type]p10:
  //   If the parameter-declaration corresponding to Pi is a function
  //   parameter pack, then the type of its declarator- id is compared with
  //   each remaining parameter type in the parameter-type-list of A. Each
  //   comparison deduces template arguments for subsequent positions in the
  //   template parameter packs expanded by the function parameter pack.

  QualType Pattern = Expansion->getPattern();
  PackDeductionScope PackScope(S, TemplateParams, Deduced, Info, Pattern);

  // A pack scope with fixed arity is not really a pack any more, so is not
  // a non-deduced context.
  if (ParamIdx + 1 == NumParams || PackScope.hasFixedArity()) {
    for (; ArgIdx < NumArgs && PackScope.hasNextElement(); ++ArgIdx) {
      // Deduce template arguments from the pattern.
      if (Sema::TemplateDeductionResult Result
            = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, Pattern,
                                                 Args[ArgIdx], Info, Deduced,
                                                 TDF, PartialOrdering))
        return Result;

      PackScope.nextPackElement();
    }
  } else {
    // C++0x [temp.deduct.type]p5:
    //   The non-deduced contexts are:
    //     - A function parameter pack that does not occur at the end of the
    //       parameter-declaration-clause.
    //
    // FIXME: There is no wording to say what we should do in this case. We
    // choose to resolve this by applying the same rule that is applied for a
    // function call: that is, deduce all contained packs to their
    // explicitly-specified values (or to <> if there is no such value).
    //
    // This is seemingly-arbitrarily different from the case of a template-id
    // with a non-trailing pack-expansion in its arguments, which renders the
    // entire template-argument-list a non-deduced context.

    // If the parameter type contains an explicitly-specified pack that we
    // could not expand, skip the number of parameters notionally created
    // by the expansion.
    Optional<unsigned> NumExpansions = Expansion->getNumExpansions();
    if (NumExpansions && !PackScope.isPartiallyExpanded()) {
      for (unsigned I = 0; I != *NumExpansions && ArgIdx < NumArgs;
           ++I, ++ArgIdx)
        PackScope.nextPackElement();
    }
  }

  // Build argument packs for each of the parameter packs expanded by this
  // pack expansion.
  if (auto Result = PackScope.finish())
    return Result;
}

// Make sure we don't have any extra arguments.
if (ArgIdx < NumArgs)
  return Sema::TDK_MiscellaneousDeductionFailure;

return Sema::TDK_Success;
1106}

1108/// Determine whether the parameter has qualifiers that the argument
1109/// lacks. Put another way, determine whether there is no way to add
1110/// a deduced set of qualifiers to the ParamType that would result in
1111/// its qualifiers matching those of the ArgType.
1112static bool hasInconsistentOrSupersetQualifiersOf(QualType ParamType,
                                                QualType ArgType) {
Qualifiers ParamQs = ParamType.getQualifiers();
Qualifiers ArgQs = ArgType.getQualifiers();

if (ParamQs == ArgQs)
  return false;

// Mismatched (but not missing) Objective-C GC attributes.
if (ParamQs.getObjCGCAttr() != ArgQs.getObjCGCAttr() &&
    ParamQs.hasObjCGCAttr())
  return true;

// Mismatched (but not missing) address spaces.
if (ParamQs.getAddressSpace() != ArgQs.getAddressSpace() &&
    ParamQs.hasAddressSpace())
  return true;

// Mismatched (but not missing) Objective-C lifetime qualifiers.
if (ParamQs.getObjCLifetime() != ArgQs.getObjCLifetime() &&
    ParamQs.hasObjCLifetime())
  return true;

// CVR qualifiers inconsistent or a superset.
return (ParamQs.getCVRQualifiers() & ~ArgQs.getCVRQualifiers()) != 0;
1137}

1139/// Compare types for equality with respect to possibly compatible
1140/// function types (noreturn adjustment, implicit calling conventions). If any
1141/// of parameter and argument is not a function, just perform type comparison.
1142///
1143/// \param Param the template parameter type.
1144///
1145/// \param Arg the argument type.
1146bool Sema::isSameOrCompatibleFunctionType(CanQualType Param,
                                        CanQualType Arg) {
const FunctionType *ParamFunction = Param->getAs<FunctionType>(),
                   *ArgFunction   = Arg->getAs<FunctionType>();

// Just compare if not functions.
if (!ParamFunction || !ArgFunction)
  return Param == Arg;

// Noreturn and noexcept adjustment.
QualType AdjustedParam;
if (IsFunctionConversion(Param, Arg, AdjustedParam))
  return Arg == Context.getCanonicalType(AdjustedParam);

// FIXME: Compatible calling conventions.

return Param == Arg;
1163}

1165/// Get the index of the first template parameter that was originally from the
1166/// innermost template-parameter-list. This is 0 except when we concatenate
1167/// the template parameter lists of a class template and a constructor template
1168/// when forming an implicit deduction guide.
1169static unsigned getFirstInnerIndex(FunctionTemplateDecl *FTD) {
auto *Guide = dyn_cast<CXXDeductionGuideDecl>(FTD->getTemplatedDecl());
if (!Guide || !Guide->isImplicit())
  return 0;
return Guide->getDeducedTemplate()->getTemplateParameters()->size();
1174}

1176/// Determine whether a type denotes a forwarding reference.
1177static bool isForwardingReference(QualType Param, unsigned FirstInnerIndex) {
// C++1z [temp.deduct.call]p3:
//   A forwarding reference is an rvalue reference to a cv-unqualified
//   template parameter that does not represent a template parameter of a
//   class template.
if (auto *ParamRef = Param->getAs<RValueReferenceType>()) {
  if (ParamRef->getPointeeType().getQualifiers())
    return false;
  auto *TypeParm = ParamRef->getPointeeType()->getAs<TemplateTypeParmType>();
  return TypeParm && TypeParm->getIndex() >= FirstInnerIndex;
}
return false;
1189}

1191/// Deduce the template arguments by comparing the parameter type and
1192/// the argument type (C++ [temp.deduct.type]).
1193///
1194/// \param S the semantic analysis object within which we are deducing
1195///
1196/// \param TemplateParams the template parameters that we are deducing
1197///
1198/// \param ParamIn the parameter type
1199///
1200/// \param ArgIn the argument type
1201///
1202/// \param Info information about the template argument deduction itself
1203///
1204/// \param Deduced the deduced template arguments
1205///
1206/// \param TDF bitwise OR of the TemplateDeductionFlags bits that describe
1207/// how template argument deduction is performed.
1208///
1209/// \param PartialOrdering Whether we're performing template argument deduction
1210/// in the context of partial ordering (C++0x [temp.deduct.partial]).
1211///
1212/// \returns the result of template argument deduction so far. Note that a
1213/// "success" result means that template argument deduction has not yet failed,
1214/// but it may still fail, later, for other reasons.
1215static Sema::TemplateDeductionResult
1216DeduceTemplateArgumentsByTypeMatch(Sema &S,
                                 TemplateParameterList *TemplateParams,
                                 QualType ParamIn, QualType ArgIn,
                                 TemplateDeductionInfo &Info,
                          SmallVectorImpl<DeducedTemplateArgument> &Deduced,
                                 unsigned TDF,
                                 bool PartialOrdering,
                                 bool DeducedFromArrayBound) {
// We only want to look at the canonical types, since typedefs and
// sugar are not part of template argument deduction.
QualType Param = S.Context.getCanonicalType(ParamIn);
QualType Arg = S.Context.getCanonicalType(ArgIn);

// If the argument type is a pack expansion, look at its pattern.
// This isn't explicitly called out
if (const PackExpansionType *ArgExpansion
                                          = dyn_cast<PackExpansionType>(Arg))
  Arg = ArgExpansion->getPattern();

if (PartialOrdering) {
  // C++11 [temp.deduct.partial]p5:
  //   Before the partial ordering is done, certain transformations are
  //   performed on the types used for partial ordering:
  //     - If P is a reference type, P is replaced by the type referred to.
  const ReferenceType *ParamRef = Param->getAs<ReferenceType>();
  if (ParamRef)
    Param = ParamRef->getPointeeType();

  //     - If A is a reference type, A is replaced by the type referred to.
  const ReferenceType *ArgRef = Arg->getAs<ReferenceType>();
  if (ArgRef)
    Arg = ArgRef->getPointeeType();

  if (ParamRef && ArgRef && S.Context.hasSameUnqualifiedType(Param, Arg)) {
    // C++11 [temp.deduct.partial]p9:
    //   If, for a given type, deduction succeeds in both directions (i.e.,
    //   the types are identical after the transformations above) and both
    //   P and A were reference types [...]:
    //     - if [one type] was an lvalue reference and [the other type] was
    //       not, [the other type] is not considered to be at least as
    //       specialized as [the first type]
    //     - if [one type] is more cv-qualified than [the other type],
    //       [the other type] is not considered to be at least as specialized
    //       as [the first type]
    // Objective-C ARC adds:
    //     - [one type] has non-trivial lifetime, [the other type] has
    //       __unsafe_unretained lifetime, and the types are otherwise
    //       identical
    //
    // A is "considered to be at least as specialized" as P iff deduction
    // succeeds, so we model this as a deduction failure. Note that
    // [the first type] is P and [the other type] is A here; the standard
    // gets this backwards.
    Qualifiers ParamQuals = Param.getQualifiers();
    Qualifiers ArgQuals = Arg.getQualifiers();
    if ((ParamRef->isLValueReferenceType() &&
         !ArgRef->isLValueReferenceType()) ||
        ParamQuals.isStrictSupersetOf(ArgQuals) ||
        (ParamQuals.hasNonTrivialObjCLifetime() &&
         ArgQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone &&
         ParamQuals.withoutObjCLifetime() ==
             ArgQuals.withoutObjCLifetime())) {
      Info.FirstArg = TemplateArgument(ParamIn);
      Info.SecondArg = TemplateArgument(ArgIn);
      return Sema::TDK_NonDeducedMismatch;
    }
  }

  // C++11 [temp.deduct.partial]p7:
  //   Remove any top-level cv-qualifiers:
  //     - If P is a cv-qualified type, P is replaced by the cv-unqualified
  //       version of P.
  Param = Param.getUnqualifiedType();
  //     - If A is a cv-qualified type, A is replaced by the cv-unqualified
  //       version of A.
  Arg = Arg.getUnqualifiedType();
} else {
  // C++0x [temp.deduct.call]p4 bullet 1:
  //   - If the original P is a reference type, the deduced A (i.e., the type
  //     referred to by the reference) can be more cv-qualified than the
  //     transformed A.
  if (TDF & TDF_ParamWithReferenceType) {
    Qualifiers Quals;
    QualType UnqualParam = S.Context.getUnqualifiedArrayType(Param, Quals);
    Quals.setCVRQualifiers(Quals.getCVRQualifiers() &
                           Arg.getCVRQualifiers());
    Param = S.Context.getQualifiedType(UnqualParam, Quals);
  }

  if ((TDF & TDF_TopLevelParameterTypeList) && !Param->isFunctionType()) {
    // C++0x [temp.deduct.type]p10:
    //   If P and A are function types that originated from deduction when
    //   taking the address of a function template (14.8.2.2) or when deducing
    //   template arguments from a function declaration (14.8.2.6) and Pi and
    //   Ai are parameters of the top-level parameter-type-list of P and A,
    //   respectively, Pi is adjusted if it is a forwarding reference and Ai
    //   is an lvalue reference, in
    //   which case the type of Pi is changed to be the template parameter
    //   type (i.e., T&& is changed to simply T). [ Note: As a result, when
    //   Pi is T&& and Ai is X&, the adjusted Pi will be T, causing T to be
    //   deduced as X&. - end note ]
    TDF &= ~TDF_TopLevelParameterTypeList;
    if (isForwardingReference(Param, 0) && Arg->isLValueReferenceType())
      Param = Param->getPointeeType();
  }
}

// C++ [temp.deduct.type]p9:
//   A template type argument T, a template template argument TT or a
//   template non-type argument i can be deduced if P and A have one of
//   the following forms:
//
//     T
//     cv-list T
if (const TemplateTypeParmType *TemplateTypeParm
      = Param->getAs<TemplateTypeParmType>()) {
  // Just skip any attempts to deduce from a placeholder type or a parameter
  // at a different depth.
  if (Arg->isPlaceholderType() ||
      Info.getDeducedDepth() != TemplateTypeParm->getDepth())
    return Sema::TDK_Success;

  unsigned Index = TemplateTypeParm->getIndex();
  bool RecanonicalizeArg = false;

  // If the argument type is an array type, move the qualifiers up to the
  // top level, so they can be matched with the qualifiers on the parameter.
  if (isa<ArrayType>(Arg)) {
    Qualifiers Quals;
    Arg = S.Context.getUnqualifiedArrayType(Arg, Quals);
    if (Quals) {
      Arg = S.Context.getQualifiedType(Arg, Quals);
      RecanonicalizeArg = true;
    }
  }

  // The argument type can not be less qualified than the parameter
  // type.
  if (!(TDF & TDF_IgnoreQualifiers) &&
      hasInconsistentOrSupersetQualifiersOf(Param, Arg)) {
    Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index));
    Info.FirstArg = TemplateArgument(Param);
    Info.SecondArg = TemplateArgument(Arg);
    return Sema::TDK_Underqualified;
  }

  // Do not match a function type with a cv-qualified type.
  // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1584
  if (Arg->isFunctionType() && Param.hasQualifiers()) {
    return Sema::TDK_NonDeducedMismatch;
  }

  assert(TemplateTypeParm->getDepth() == Info.getDeducedDepth() &&((TemplateTypeParm->getDepth() == Info.getDeducedDepth() &&
 "saw template type parameter with wrong depth") ? static_cast
<void> (0) : __assert_fail ("TemplateTypeParm->getDepth() == Info.getDeducedDepth() && \"saw template type parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1369, __PRETTY_FUNCTION__))
         "saw template type parameter with wrong depth")((TemplateTypeParm->getDepth() == Info.getDeducedDepth() &&
 "saw template type parameter with wrong depth") ? static_cast
<void> (0) : __assert_fail ("TemplateTypeParm->getDepth() == Info.getDeducedDepth() && \"saw template type parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1369, __PRETTY_FUNCTION__));
  assert(Arg != S.Context.OverloadTy && "Unresolved overloaded function")((Arg != S.Context.OverloadTy && "Unresolved overloaded function"
) ? static_cast<void> (0) : __assert_fail ("Arg != S.Context.OverloadTy && \"Unresolved overloaded function\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1370, __PRETTY_FUNCTION__));
  QualType DeducedType = Arg;

  // Remove any qualifiers on the parameter from the deduced type.
  // We checked the qualifiers for consistency above.
  Qualifiers DeducedQs = DeducedType.getQualifiers();
  Qualifiers ParamQs = Param.getQualifiers();
  DeducedQs.removeCVRQualifiers(ParamQs.getCVRQualifiers());
  if (ParamQs.hasObjCGCAttr())
    DeducedQs.removeObjCGCAttr();
  if (ParamQs.hasAddressSpace())
    DeducedQs.removeAddressSpace();
  if (ParamQs.hasObjCLifetime())
    DeducedQs.removeObjCLifetime();

  // Objective-C ARC:
  //   If template deduction would produce a lifetime qualifier on a type
  //   that is not a lifetime type, template argument deduction fails.
  if (ParamQs.hasObjCLifetime() && !DeducedType->isObjCLifetimeType() &&
      !DeducedType->isDependentType()) {
    Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index));
    Info.FirstArg = TemplateArgument(Param);
    Info.SecondArg = TemplateArgument(Arg);
    return Sema::TDK_Underqualified;
  }

  // Objective-C ARC:
  //   If template deduction would produce an argument type with lifetime type
  //   but no lifetime qualifier, the __strong lifetime qualifier is inferred.
  if (S.getLangOpts().ObjCAutoRefCount &&
      DeducedType->isObjCLifetimeType() &&
      !DeducedQs.hasObjCLifetime())
    DeducedQs.setObjCLifetime(Qualifiers::OCL_Strong);

  DeducedType = S.Context.getQualifiedType(DeducedType.getUnqualifiedType(),
                                           DeducedQs);

  if (RecanonicalizeArg)
    DeducedType = S.Context.getCanonicalType(DeducedType);

  DeducedTemplateArgument NewDeduced(DeducedType, DeducedFromArrayBound);
  DeducedTemplateArgument Result = checkDeducedTemplateArguments(S.Context,
                                                               Deduced[Index],
                                                                 NewDeduced);
  if (Result.isNull()) {
    Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index));
    Info.FirstArg = Deduced[Index];
    Info.SecondArg = NewDeduced;
    return Sema::TDK_Inconsistent;
  }

  Deduced[Index] = Result;
  return Sema::TDK_Success;
}

// Set up the template argument deduction information for a failure.
Info.FirstArg = TemplateArgument(ParamIn);
Info.SecondArg = TemplateArgument(ArgIn);

// If the parameter is an already-substituted template parameter
// pack, do nothing: we don't know which of its arguments to look
// at, so we have to wait until all of the parameter packs in this
// expansion have arguments.
if (isa<SubstTemplateTypeParmPackType>(Param))
  return Sema::TDK_Success;

// Check the cv-qualifiers on the parameter and argument types.
CanQualType CanParam = S.Context.getCanonicalType(Param);
CanQualType CanArg = S.Context.getCanonicalType(Arg);
if (!(TDF & TDF_IgnoreQualifiers)) {
  if (TDF & TDF_ParamWithReferenceType) {
    if (hasInconsistentOrSupersetQualifiersOf(Param, Arg))
      return Sema::TDK_NonDeducedMismatch;
  } else if (TDF & TDF_ArgWithReferenceType) {
    // C++ [temp.deduct.conv]p4:
    //   If the original A is a reference type, A can be more cv-qualified
    //   than the deduced A
    if (!Arg.getQualifiers().compatiblyIncludes(Param.getQualifiers()))
      return Sema::TDK_NonDeducedMismatch;

    // Strip out all extra qualifiers from the argument to figure out the
    // type we're converting to, prior to the qualification conversion.
    Qualifiers Quals;
    Arg = S.Context.getUnqualifiedArrayType(Arg, Quals);
    Arg = S.Context.getQualifiedType(Arg, Param.getQualifiers());
  } else if (!IsPossiblyOpaquelyQualifiedType(Param)) {
    if (Param.getCVRQualifiers() != Arg.getCVRQualifiers())
      return Sema::TDK_NonDeducedMismatch;
  }

  // If the parameter type is not dependent, there is nothing to deduce.
  if (!Param->isDependentType()) {
    if (!(TDF & TDF_SkipNonDependent)) {
      bool NonDeduced =
          (TDF & TDF_AllowCompatibleFunctionType)
              ? !S.isSameOrCompatibleFunctionType(CanParam, CanArg)
              : Param != Arg;
      if (NonDeduced) {
        return Sema::TDK_NonDeducedMismatch;
      }
    }
    return Sema::TDK_Success;
  }
} else if (!Param->isDependentType()) {
  CanQualType ParamUnqualType = CanParam.getUnqualifiedType(),
              ArgUnqualType = CanArg.getUnqualifiedType();
  bool Success =
      (TDF & TDF_AllowCompatibleFunctionType)
          ? S.isSameOrCompatibleFunctionType(ParamUnqualType, ArgUnqualType)
          : ParamUnqualType == ArgUnqualType;
  if (Success)
    return Sema::TDK_Success;
}

switch (Param->getTypeClass()) {
  // Non-canonical types cannot appear here.
1486#define NON_CANONICAL_TYPE(Class, Base) \
case Type::Class: llvm_unreachable("deducing non-canonical type: " #Class)::llvm::llvm_unreachable_internal("deducing non-canonical type: "
 #Class, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1487);
1488#define TYPE(Class, Base)
1489#include "clang/AST/TypeNodes.inc"

  case Type::TemplateTypeParm:
  case Type::SubstTemplateTypeParmPack:
    llvm_unreachable("Type nodes handled above")::llvm::llvm_unreachable_internal("Type nodes handled above",
 "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1493);

  // These types cannot be dependent, so simply check whether the types are
  // the same.
  case Type::Builtin:
  case Type::VariableArray:
  case Type::Vector:
  case Type::FunctionNoProto:
  case Type::Record:
  case Type::Enum:
  case Type::ObjCObject:
  case Type::ObjCInterface:
  case Type::ObjCObjectPointer:
    if (TDF & TDF_SkipNonDependent)
      return Sema::TDK_Success;

    if (TDF & TDF_IgnoreQualifiers) {
      Param = Param.getUnqualifiedType();
      Arg = Arg.getUnqualifiedType();
    }

    return Param == Arg? Sema::TDK_Success : Sema::TDK_NonDeducedMismatch;

  //     _Complex T   [placeholder extension]
  case Type::Complex:
    if (const ComplexType *ComplexArg = Arg->getAs<ComplexType>())
      return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                  cast<ComplexType>(Param)->getElementType(),
                                  ComplexArg->getElementType(),
                                  Info, Deduced, TDF);

    return Sema::TDK_NonDeducedMismatch;

  //     _Atomic T   [extension]
  case Type::Atomic:
    if (const AtomicType *AtomicArg = Arg->getAs<AtomicType>())
      return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                     cast<AtomicType>(Param)->getValueType(),
                                     AtomicArg->getValueType(),
                                     Info, Deduced, TDF);

    return Sema::TDK_NonDeducedMismatch;

  //     T *
  case Type::Pointer: {
    QualType PointeeType;
    if (const PointerType *PointerArg = Arg->getAs<PointerType>()) {
      PointeeType = PointerArg->getPointeeType();
    } else if (const ObjCObjectPointerType *PointerArg
                 = Arg->getAs<ObjCObjectPointerType>()) {
      PointeeType = PointerArg->getPointeeType();
    } else {
      return Sema::TDK_NonDeducedMismatch;
    }

    unsigned SubTDF = TDF & (TDF_IgnoreQualifiers | TDF_DerivedClass);
    return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                   cast<PointerType>(Param)->getPointeeType(),
                                   PointeeType,
                                   Info, Deduced, SubTDF);
  }

  //     T &
  case Type::LValueReference: {
    const LValueReferenceType *ReferenceArg =
        Arg->getAs<LValueReferenceType>();
    if (!ReferenceArg)
      return Sema::TDK_NonDeducedMismatch;

    return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                         cast<LValueReferenceType>(Param)->getPointeeType(),
                         ReferenceArg->getPointeeType(), Info, Deduced, 0);
  }

  //     T && [C++0x]
  case Type::RValueReference: {
    const RValueReferenceType *ReferenceArg =
        Arg->getAs<RValueReferenceType>();
    if (!ReferenceArg)
      return Sema::TDK_NonDeducedMismatch;

    return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                           cast<RValueReferenceType>(Param)->getPointeeType(),
                           ReferenceArg->getPointeeType(),
                           Info, Deduced, 0);
  }

  //     T [] (implied, but not stated explicitly)
  case Type::IncompleteArray: {
    const IncompleteArrayType *IncompleteArrayArg =
      S.Context.getAsIncompleteArrayType(Arg);
    if (!IncompleteArrayArg)
      return Sema::TDK_NonDeducedMismatch;

    unsigned SubTDF = TDF & TDF_IgnoreQualifiers;
    return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                  S.Context.getAsIncompleteArrayType(Param)->getElementType(),
                  IncompleteArrayArg->getElementType(),
                  Info, Deduced, SubTDF);
  }

  //     T [integer-constant]
  case Type::ConstantArray: {
    const ConstantArrayType *ConstantArrayArg =
      S.Context.getAsConstantArrayType(Arg);
    if (!ConstantArrayArg)
      return Sema::TDK_NonDeducedMismatch;

    const ConstantArrayType *ConstantArrayParm =
      S.Context.getAsConstantArrayType(Param);
    if (ConstantArrayArg->getSize() != ConstantArrayParm->getSize())
      return Sema::TDK_NonDeducedMismatch;

    unsigned SubTDF = TDF & TDF_IgnoreQualifiers;
    return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                         ConstantArrayParm->getElementType(),
                                         ConstantArrayArg->getElementType(),
                                         Info, Deduced, SubTDF);
  }

  //     type [i]
  case Type::DependentSizedArray: {
    const ArrayType *ArrayArg = S.Context.getAsArrayType(Arg);
    if (!ArrayArg)
      return Sema::TDK_NonDeducedMismatch;

    unsigned SubTDF = TDF & TDF_IgnoreQualifiers;

    // Check the element type of the arrays
    const DependentSizedArrayType *DependentArrayParm
      = S.Context.getAsDependentSizedArrayType(Param);
    if (Sema::TemplateDeductionResult Result
          = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                        DependentArrayParm->getElementType(),
                                        ArrayArg->getElementType(),
                                        Info, Deduced, SubTDF))
      return Result;

    // Determine the array bound is something we can deduce.
    NonTypeTemplateParmDecl *NTTP
      = getDeducedParameterFromExpr(Info, DependentArrayParm->getSizeExpr());
    if (!NTTP)
      return Sema::TDK_Success;

    // We can perform template argument deduction for the given non-type
    // template parameter.
    assert(NTTP->getDepth() == Info.getDeducedDepth() &&((NTTP->getDepth() == Info.getDeducedDepth() && "saw non-type template parameter with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1640, __PRETTY_FUNCTION__))
           "saw non-type template parameter with wrong depth")((NTTP->getDepth() == Info.getDeducedDepth() && "saw non-type template parameter with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1640, __PRETTY_FUNCTION__));
    if (const ConstantArrayType *ConstantArrayArg
          = dyn_cast<ConstantArrayType>(ArrayArg)) {
      llvm::APSInt Size(ConstantArrayArg->getSize());
      return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, Size,
                                           S.Context.getSizeType(),
                                           /*ArrayBound=*/true,
                                           Info, Deduced);
    }
    if (const DependentSizedArrayType *DependentArrayArg
          = dyn_cast<DependentSizedArrayType>(ArrayArg))
      if (DependentArrayArg->getSizeExpr())
        return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
                                             DependentArrayArg->getSizeExpr(),
                                             Info, Deduced);

    // Incomplete type does not match a dependently-sized array type
    return Sema::TDK_NonDeducedMismatch;
  }

  //     type(*)(T)
  //     T(*)()
  //     T(*)(T)
  case Type::FunctionProto: {
    unsigned SubTDF = TDF & TDF_TopLevelParameterTypeList;
    const FunctionProtoType *FunctionProtoArg =
      dyn_cast<FunctionProtoType>(Arg);
    if (!FunctionProtoArg)
      return Sema::TDK_NonDeducedMismatch;

    const FunctionProtoType *FunctionProtoParam =
      cast<FunctionProtoType>(Param);

    if (FunctionProtoParam->getMethodQuals()
          != FunctionProtoArg->getMethodQuals() ||
        FunctionProtoParam->getRefQualifier()
          != FunctionProtoArg->getRefQualifier() ||
        FunctionProtoParam->isVariadic() != FunctionProtoArg->isVariadic())
      return Sema::TDK_NonDeducedMismatch;

    // Check return types.
    if (auto Result = DeduceTemplateArgumentsByTypeMatch(
            S, TemplateParams, FunctionProtoParam->getReturnType(),
            FunctionProtoArg->getReturnType(), Info, Deduced, 0))
      return Result;

    // Check parameter types.
    if (auto Result = DeduceTemplateArguments(
            S, TemplateParams, FunctionProtoParam->param_type_begin(),
            FunctionProtoParam->getNumParams(),
            FunctionProtoArg->param_type_begin(),
            FunctionProtoArg->getNumParams(), Info, Deduced, SubTDF))
      return Result;

    if (TDF & TDF_AllowCompatibleFunctionType)
      return Sema::TDK_Success;

    // FIXME: Per core-2016/10/1019 (no corresponding core issue yet), permit
    // deducing through the noexcept-specifier if it's part of the canonical
    // type. libstdc++ relies on this.
    Expr *NoexceptExpr = FunctionProtoParam->getNoexceptExpr();
    if (NonTypeTemplateParmDecl *NTTP =
        NoexceptExpr ? getDeducedParameterFromExpr(Info, NoexceptExpr)
                     : nullptr) {
      assert(NTTP->getDepth() == Info.getDeducedDepth() &&((NTTP->getDepth() == Info.getDeducedDepth() && "saw non-type template parameter with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1705, __PRETTY_FUNCTION__))
             "saw non-type template parameter with wrong depth")((NTTP->getDepth() == Info.getDeducedDepth() && "saw non-type template parameter with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1705, __PRETTY_FUNCTION__));

      llvm::APSInt Noexcept(1);
      switch (FunctionProtoArg->canThrow()) {
      case CT_Cannot:
        Noexcept = 1;
        LLVM_FALLTHROUGH[[gnu::fallthrough]];

      case CT_Can:
        // We give E in noexcept(E) the "deduced from array bound" treatment.
        // FIXME: Should we?
        return DeduceNonTypeTemplateArgument(
            S, TemplateParams, NTTP, Noexcept, S.Context.BoolTy,
            /*ArrayBound*/true, Info, Deduced);

      case CT_Dependent:
        if (Expr *ArgNoexceptExpr = FunctionProtoArg->getNoexceptExpr())
          return DeduceNonTypeTemplateArgument(
              S, TemplateParams, NTTP, ArgNoexceptExpr, Info, Deduced);
        // Can't deduce anything from throw(T...).
        break;
      }
    }
    // FIXME: Detect non-deduced exception specification mismatches?
    //
    // Careful about [temp.deduct.call] and [temp.deduct.conv], which allow
    // top-level differences in noexcept-specifications.

    return Sema::TDK_Success;
  }

  case Type::InjectedClassName:
    // Treat a template's injected-class-name as if the template
    // specialization type had been used.
    Param = cast<InjectedClassNameType>(Param)
      ->getInjectedSpecializationType();
    assert(isa<TemplateSpecializationType>(Param) &&((isa<TemplateSpecializationType>(Param) && "injected class name is not a template specialization type"
) ? static_cast<void> (0) : __assert_fail ("isa<TemplateSpecializationType>(Param) && \"injected class name is not a template specialization type\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1742, __PRETTY_FUNCTION__))
           "injected class name is not a template specialization type")((isa<TemplateSpecializationType>(Param) && "injected class name is not a template specialization type"
) ? static_cast<void> (0) : __assert_fail ("isa<TemplateSpecializationType>(Param) && \"injected class name is not a template specialization type\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1742, __PRETTY_FUNCTION__));
    LLVM_FALLTHROUGH[[gnu::fallthrough]];

  //     template-name<T> (where template-name refers to a class template)
  //     template-name<i>
  //     TT<T>
  //     TT<i>
  //     TT<>
  case Type::TemplateSpecialization: {
    const TemplateSpecializationType *SpecParam =
        cast<TemplateSpecializationType>(Param);

    // When Arg cannot be a derived class, we can just try to deduce template
    // arguments from the template-id.
    const RecordType *RecordT = Arg->getAs<RecordType>();
    if (!(TDF & TDF_DerivedClass) || !RecordT)
      return DeduceTemplateArguments(S, TemplateParams, SpecParam, Arg, Info,
                                     Deduced);

    SmallVector<DeducedTemplateArgument, 8> DeducedOrig(Deduced.begin(),
                                                        Deduced.end());

    Sema::TemplateDeductionResult Result = DeduceTemplateArguments(
        S, TemplateParams, SpecParam, Arg, Info, Deduced);

    if (Result == Sema::TDK_Success)
      return Result;

    // We cannot inspect base classes as part of deduction when the type
    // is incomplete, so either instantiate any templates necessary to
    // complete the type, or skip over it if it cannot be completed.
    if (!S.isCompleteType(Info.getLocation(), Arg))
      return Result;

    // C++14 [temp.deduct.call] p4b3:
    //   If P is a class and P has the form simple-template-id, then the
    //   transformed A can be a derived class of the deduced A. Likewise if
    //   P is a pointer to a class of the form simple-template-id, the
    //   transformed A can be a pointer to a derived class pointed to by the
    //   deduced A.
    //
    //   These alternatives are considered only if type deduction would
    //   otherwise fail. If they yield more than one possible deduced A, the
    //   type deduction fails.

    // Reset the incorrectly deduced argument from above.
    Deduced = DeducedOrig;

    // Use data recursion to crawl through the list of base classes.
    // Visited contains the set of nodes we have already visited, while
    // ToVisit is our stack of records that we still need to visit.
    llvm::SmallPtrSet<const RecordType *, 8> Visited;
    SmallVector<const RecordType *, 8> ToVisit;
    ToVisit.push_back(RecordT);
    bool Successful = false;
    SmallVector<DeducedTemplateArgument, 8> SuccessfulDeduced;
    while (!ToVisit.empty()) {
      // Retrieve the next class in the inheritance hierarchy.
      const RecordType *NextT = ToVisit.pop_back_val();

      // If we have already seen this type, skip it.
      if (!Visited.insert(NextT).second)
        continue;

      // If this is a base class, try to perform template argument
      // deduction from it.
      if (NextT != RecordT) {
        TemplateDeductionInfo BaseInfo(Info.getLocation());
        Sema::TemplateDeductionResult BaseResult =
            DeduceTemplateArguments(S, TemplateParams, SpecParam,
                                    QualType(NextT, 0), BaseInfo, Deduced);

        // If template argument deduction for this base was successful,
        // note that we had some success. Otherwise, ignore any deductions
        // from this base class.
        if (BaseResult == Sema::TDK_Success) {
          // If we've already seen some success, then deduction fails due to
          // an ambiguity (temp.deduct.call p5).
          if (Successful)
            return Sema::TDK_MiscellaneousDeductionFailure;

          Successful = true;
          std::swap(SuccessfulDeduced, Deduced);

          Info.Param = BaseInfo.Param;
          Info.FirstArg = BaseInfo.FirstArg;
          Info.SecondArg = BaseInfo.SecondArg;
        }

        Deduced = DeducedOrig;
      }

      // Visit base classes
      CXXRecordDecl *Next = cast<CXXRecordDecl>(NextT->getDecl());
      for (const auto &Base : Next->bases()) {
        assert(Base.getType()->isRecordType() &&((Base.getType()->isRecordType() && "Base class that isn't a record?"
) ? static_cast<void> (0) : __assert_fail ("Base.getType()->isRecordType() && \"Base class that isn't a record?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1838, __PRETTY_FUNCTION__))
               "Base class that isn't a record?")((Base.getType()->isRecordType() && "Base class that isn't a record?"
) ? static_cast<void> (0) : __assert_fail ("Base.getType()->isRecordType() && \"Base class that isn't a record?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1838, __PRETTY_FUNCTION__));
        ToVisit.push_back(Base.getType()->getAs<RecordType>());
      }
    }

    if (Successful) {
      std::swap(SuccessfulDeduced, Deduced);
      return Sema::TDK_Success;
    }

    return Result;
  }

  //     T type::*
  //     T T::*
  //     T (type::*)()
  //     type (T::*)()
  //     type (type::*)(T)
  //     type (T::*)(T)
  //     T (type::*)(T)
  //     T (T::*)()
  //     T (T::*)(T)
  case Type::MemberPointer: {
    const MemberPointerType *MemPtrParam = cast<MemberPointerType>(Param);
    const MemberPointerType *MemPtrArg = dyn_cast<MemberPointerType>(Arg);
    if (!MemPtrArg)
      return Sema::TDK_NonDeducedMismatch;

    QualType ParamPointeeType = MemPtrParam->getPointeeType();
    if (ParamPointeeType->isFunctionType())
      S.adjustMemberFunctionCC(ParamPointeeType, /*IsStatic=*/true,
                               /*IsCtorOrDtor=*/false, Info.getLocation());
    QualType ArgPointeeType = MemPtrArg->getPointeeType();
    if (ArgPointeeType->isFunctionType())
      S.adjustMemberFunctionCC(ArgPointeeType, /*IsStatic=*/true,
                               /*IsCtorOrDtor=*/false, Info.getLocation());

    if (Sema::TemplateDeductionResult Result
          = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                               ParamPointeeType,
                                               ArgPointeeType,
                                               Info, Deduced,
                                               TDF & TDF_IgnoreQualifiers))
      return Result;

    return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                         QualType(MemPtrParam->getClass(), 0),
                                         QualType(MemPtrArg->getClass(), 0),
                                         Info, Deduced,
                                         TDF & TDF_IgnoreQualifiers);
  }

  //     (clang extension)
  //
  //     type(^)(T)
  //     T(^)()
  //     T(^)(T)
  case Type::BlockPointer: {
    const BlockPointerType *BlockPtrParam = cast<BlockPointerType>(Param);
    const BlockPointerType *BlockPtrArg = dyn_cast<BlockPointerType>(Arg);

    if (!BlockPtrArg)
      return Sema::TDK_NonDeducedMismatch;

    return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                              BlockPtrParam->getPointeeType(),
                                              BlockPtrArg->getPointeeType(),
                                              Info, Deduced, 0);
  }

  //     (clang extension)
  //
  //     T __attribute__(((ext_vector_type(<integral constant>))))
  case Type::ExtVector: {
    const ExtVectorType *VectorParam = cast<ExtVectorType>(Param);
    if (const ExtVectorType *VectorArg = dyn_cast<ExtVectorType>(Arg)) {
      // Make sure that the vectors have the same number of elements.
      if (VectorParam->getNumElements() != VectorArg->getNumElements())
        return Sema::TDK_NonDeducedMismatch;

      // Perform deduction on the element types.
      return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                                VectorParam->getElementType(),
                                                VectorArg->getElementType(),
                                                Info, Deduced, TDF);
    }

    if (const DependentSizedExtVectorType *VectorArg
                              = dyn_cast<DependentSizedExtVectorType>(Arg)) {
      // We can't check the number of elements, since the argument has a
      // dependent number of elements. This can only occur during partial
      // ordering.

      // Perform deduction on the element types.
      return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                                VectorParam->getElementType(),
                                                VectorArg->getElementType(),
                                                Info, Deduced, TDF);
    }

    return Sema::TDK_NonDeducedMismatch;
  }

  case Type::DependentVector: {
    const auto *VectorParam = cast<DependentVectorType>(Param);

    if (const auto *VectorArg = dyn_cast<VectorType>(Arg)) {
      // Perform deduction on the element types.
      if (Sema::TemplateDeductionResult Result =
              DeduceTemplateArgumentsByTypeMatch(
                  S, TemplateParams, VectorParam->getElementType(),
                  VectorArg->getElementType(), Info, Deduced, TDF))
        return Result;

      // Perform deduction on the vector size, if we can.
      NonTypeTemplateParmDecl *NTTP =
          getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr());
      if (!NTTP)
        return Sema::TDK_Success;

      llvm::APSInt ArgSize(S.Context.getTypeSize(S.Context.IntTy), false);
      ArgSize = VectorArg->getNumElements();
      // Note that we use the "array bound" rules here; just like in that
      // case, we don't have any particular type for the vector size, but
      // we can provide one if necessary.
      return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, ArgSize,
                                           S.Context.UnsignedIntTy, true,
                                           Info, Deduced);
    }

    if (const auto *VectorArg = dyn_cast<DependentVectorType>(Arg)) {
      // Perform deduction on the element types.
      if (Sema::TemplateDeductionResult Result =
              DeduceTemplateArgumentsByTypeMatch(
                  S, TemplateParams, VectorParam->getElementType(),
                  VectorArg->getElementType(), Info, Deduced, TDF))
        return Result;

      // Perform deduction on the vector size, if we can.
      NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr(
          Info, VectorParam->getSizeExpr());
      if (!NTTP)
        return Sema::TDK_Success;

      return DeduceNonTypeTemplateArgument(
          S, TemplateParams, NTTP, VectorArg->getSizeExpr(), Info, Deduced);
    }

    return Sema::TDK_NonDeducedMismatch;
  }

  //     (clang extension)
  //
  //     T __attribute__(((ext_vector_type(N))))
  case Type::DependentSizedExtVector: {
    const DependentSizedExtVectorType *VectorParam
      = cast<DependentSizedExtVectorType>(Param);

    if (const ExtVectorType *VectorArg = dyn_cast<ExtVectorType>(Arg)) {
      // Perform deduction on the element types.
      if (Sema::TemplateDeductionResult Result
            = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                                VectorParam->getElementType(),
                                                 VectorArg->getElementType(),
                                                 Info, Deduced, TDF))
        return Result;

      // Perform deduction on the vector size, if we can.
      NonTypeTemplateParmDecl *NTTP
        = getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr());
      if (!NTTP)
        return Sema::TDK_Success;

      llvm::APSInt ArgSize(S.Context.getTypeSize(S.Context.IntTy), false);
      ArgSize = VectorArg->getNumElements();
      // Note that we use the "array bound" rules here; just like in that
      // case, we don't have any particular type for the vector size, but
      // we can provide one if necessary.
      return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, ArgSize,
                                           S.Context.IntTy, true, Info,
                                           Deduced);
    }

    if (const DependentSizedExtVectorType *VectorArg
                              = dyn_cast<DependentSizedExtVectorType>(Arg)) {
      // Perform deduction on the element types.
      if (Sema::TemplateDeductionResult Result
          = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                               VectorParam->getElementType(),
                                               VectorArg->getElementType(),
                                               Info, Deduced, TDF))
        return Result;

      // Perform deduction on the vector size, if we can.
      NonTypeTemplateParmDecl *NTTP
        = getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr());
      if (!NTTP)
        return Sema::TDK_Success;

      return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
                                           VectorArg->getSizeExpr(),
                                           Info, Deduced);
    }

    return Sema::TDK_NonDeducedMismatch;
  }

  //     (clang extension)
  //
  //     T __attribute__(((address_space(N))))
  case Type::DependentAddressSpace: {
    const DependentAddressSpaceType *AddressSpaceParam =
        cast<DependentAddressSpaceType>(Param);

    if (const DependentAddressSpaceType *AddressSpaceArg =
            dyn_cast<DependentAddressSpaceType>(Arg)) {
      // Perform deduction on the pointer type.
      if (Sema::TemplateDeductionResult Result =
              DeduceTemplateArgumentsByTypeMatch(
                  S, TemplateParams, AddressSpaceParam->getPointeeType(),
                  AddressSpaceArg->getPointeeType(), Info, Deduced, TDF))
        return Result;

      // Perform deduction on the address space, if we can.
      NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr(
          Info, AddressSpaceParam->getAddrSpaceExpr());
      if (!NTTP)
        return Sema::TDK_Success;

      return DeduceNonTypeTemplateArgument(
          S, TemplateParams, NTTP, AddressSpaceArg->getAddrSpaceExpr(), Info,
          Deduced);
    }

    if (isTargetAddressSpace(Arg.getAddressSpace())) {
      llvm::APSInt ArgAddressSpace(S.Context.getTypeSize(S.Context.IntTy),
                                   false);
      ArgAddressSpace = toTargetAddressSpace(Arg.getAddressSpace());

      // Perform deduction on the pointer types.
      if (Sema::TemplateDeductionResult Result =
              DeduceTemplateArgumentsByTypeMatch(
                  S, TemplateParams, AddressSpaceParam->getPointeeType(),
                  S.Context.removeAddrSpaceQualType(Arg), Info, Deduced, TDF))
        return Result;

      // Perform deduction on the address space, if we can.
      NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr(
          Info, AddressSpaceParam->getAddrSpaceExpr());
      if (!NTTP)
        return Sema::TDK_Success;

      return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
                                           ArgAddressSpace, S.Context.IntTy,
                                           true, Info, Deduced);
    }

    return Sema::TDK_NonDeducedMismatch;
  }

  case Type::TypeOfExpr:
  case Type::TypeOf:
  case Type::DependentName:
  case Type::UnresolvedUsing:
  case Type::Decltype:
  case Type::UnaryTransform:
  case Type::Auto:
  case Type::DeducedTemplateSpecialization:
  case Type::DependentTemplateSpecialization:
  case Type::PackExpansion:
  case Type::Pipe:
    // No template argument deduction for these types
    return Sema::TDK_Success;
}

llvm_unreachable("Invalid Type Class!")::llvm::llvm_unreachable_internal("Invalid Type Class!", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2113);
2114}

2116static Sema::TemplateDeductionResult
2117DeduceTemplateArguments(Sema &S,
                      TemplateParameterList *TemplateParams,
                      const TemplateArgument &Param,
                      TemplateArgument Arg,
                      TemplateDeductionInfo &Info,
                      SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
// If the template argument is a pack expansion, perform template argument
// deduction against the pattern of that expansion. This only occurs during
// partial ordering.
if (Arg.isPackExpansion())
  Arg = Arg.getPackExpansionPattern();

switch (Param.getKind()) {
case TemplateArgument::Null:
  llvm_unreachable("Null template argument in parameter list")::llvm::llvm_unreachable_internal("Null template argument in parameter list"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2131);

case TemplateArgument::Type:
  if (Arg.getKind() == TemplateArgument::Type)
    return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
                                              Param.getAsType(),
                                              Arg.getAsType(),
                                              Info, Deduced, 0);
  Info.FirstArg = Param;
  Info.SecondArg = Arg;
  return Sema::TDK_NonDeducedMismatch;

case TemplateArgument::Template:
  if (Arg.getKind() == TemplateArgument::Template)
    return DeduceTemplateArguments(S, TemplateParams,
                                   Param.getAsTemplate(),
                                   Arg.getAsTemplate(), Info, Deduced);
  Info.FirstArg = Param;
  Info.SecondArg = Arg;
  return Sema::TDK_NonDeducedMismatch;

case TemplateArgument::TemplateExpansion:
  llvm_unreachable("caller should handle pack expansions")::llvm::llvm_unreachable_internal("caller should handle pack expansions"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2153);

case TemplateArgument::Declaration:
  if (Arg.getKind() == TemplateArgument::Declaration &&
      isSameDeclaration(Param.getAsDecl(), Arg.getAsDecl()))
    return Sema::TDK_Success;

  Info.FirstArg = Param;
  Info.SecondArg = Arg;
  return Sema::TDK_NonDeducedMismatch;

case TemplateArgument::NullPtr:
  if (Arg.getKind() == TemplateArgument::NullPtr &&
      S.Context.hasSameType(Param.getNullPtrType(), Arg.getNullPtrType()))
    return Sema::TDK_Success;

  Info.FirstArg = Param;
  Info.SecondArg = Arg;
  return Sema::TDK_NonDeducedMismatch;

case TemplateArgument::Integral:
  if (Arg.getKind() == TemplateArgument::Integral) {
    if (hasSameExtendedValue(Param.getAsIntegral(), Arg.getAsIntegral()))
      return Sema::TDK_Success;

    Info.FirstArg = Param;
    Info.SecondArg = Arg;
    return Sema::TDK_NonDeducedMismatch;
  }

  if (Arg.getKind() == TemplateArgument::Expression) {
    Info.FirstArg = Param;
    Info.SecondArg = Arg;
    return Sema::TDK_NonDeducedMismatch;
  }

  Info.FirstArg = Param;
  Info.SecondArg = Arg;
  return Sema::TDK_NonDeducedMismatch;

case TemplateArgument::Expression:
  if (NonTypeTemplateParmDecl *NTTP
        = getDeducedParameterFromExpr(Info, Param.getAsExpr())) {
    if (Arg.getKind() == TemplateArgument::Integral)
      return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
                                           Arg.getAsIntegral(),
                                           Arg.getIntegralType(),
                                           /*ArrayBound=*/false,
                                           Info, Deduced);
    if (Arg.getKind() == TemplateArgument::NullPtr)
      return DeduceNullPtrTemplateArgument(S, TemplateParams, NTTP,
                                           Arg.getNullPtrType(),
                                           Info, Deduced);
    if (Arg.getKind() == TemplateArgument::Expression)
      return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
                                           Arg.getAsExpr(), Info, Deduced);
    if (Arg.getKind() == TemplateArgument::Declaration)
      return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
                                           Arg.getAsDecl(),
                                           Arg.getParamTypeForDecl(),
                                           Info, Deduced);

    Info.FirstArg = Param;
    Info.SecondArg = Arg;
    return Sema::TDK_NonDeducedMismatch;
  }

  // Can't deduce anything, but that's okay.
  return Sema::TDK_Success;

case TemplateArgument::Pack:
  llvm_unreachable("Argument packs should be expanded by the caller!")::llvm::llvm_unreachable_internal("Argument packs should be expanded by the caller!"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2224);
}

llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2227);
2228}

2230/// Determine whether there is a template argument to be used for
2231/// deduction.
2232///
2233/// This routine "expands" argument packs in-place, overriding its input
2234/// parameters so that \c Args[ArgIdx] will be the available template argument.
2235///
2236/// \returns true if there is another template argument (which will be at
2237/// \c Args[ArgIdx]), false otherwise.
2238static bool hasTemplateArgumentForDeduction(ArrayRef<TemplateArgument> &Args,
                                          unsigned &ArgIdx) {
if (ArgIdx == Args.size())
  return false;

const TemplateArgument &Arg = Args[ArgIdx];
if (Arg.getKind() != TemplateArgument::Pack)
  return true;

assert(ArgIdx == Args.size() - 1 && "Pack not at the end of argument list?")((ArgIdx == Args.size() - 1 && "Pack not at the end of argument list?"
) ? static_cast<void> (0) : __assert_fail ("ArgIdx == Args.size() - 1 && \"Pack not at the end of argument list?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2247, __PRETTY_FUNCTION__));
Args = Arg.pack_elements();
ArgIdx = 0;
return ArgIdx < Args.size();
2251}

2253/// Determine whether the given set of template arguments has a pack
2254/// expansion that is not the last template argument.
2255static bool hasPackExpansionBeforeEnd(ArrayRef<TemplateArgument> Args) {
bool FoundPackExpansion = false;
for (const auto &A : Args) {
  if (FoundPackExpansion)
    return true;

  if (A.getKind() == TemplateArgument::Pack)
    return hasPackExpansionBeforeEnd(A.pack_elements());

  // FIXME: If this is a fixed-arity pack expansion from an outer level of
  // templates, it should not be treated as a pack expansion.
  if (A.isPackExpansion())
    FoundPackExpansion = true;
}

return false;
2271}

2273static Sema::TemplateDeductionResult
2274DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams,
                      ArrayRef<TemplateArgument> Params,
                      ArrayRef<TemplateArgument> Args,
                      TemplateDeductionInfo &Info,
                      SmallVectorImpl<DeducedTemplateArgument> &Deduced,
                      bool NumberOfArgumentsMustMatch) {
// C++0x [temp.deduct.type]p9:
//   If the template argument list of P contains a pack expansion that is not
//   the last template argument, the entire template argument list is a
//   non-deduced context.
if (hasPackExpansionBeforeEnd(Params))
  return Sema::TDK_Success;

// C++0x [temp.deduct.type]p9:
//   If P has a form that contains <T> or <i>, then each argument Pi of the
//   respective template argument list P is compared with the corresponding
//   argument Ai of the corresponding template argument list of A.
unsigned ArgIdx = 0, ParamIdx = 0;
for (; hasTemplateArgumentForDeduction(Params, ParamIdx); ++ParamIdx) {
  if (!Params[ParamIdx].isPackExpansion()) {
    // The simple case: deduce template arguments by matching Pi and Ai.

    // Check whether we have enough arguments.
    if (!hasTemplateArgumentForDeduction(Args, ArgIdx))
      return NumberOfArgumentsMustMatch
                 ? Sema::TDK_MiscellaneousDeductionFailure
                 : Sema::TDK_Success;

    // C++1z [temp.deduct.type]p9:
    //   During partial ordering, if Ai was originally a pack expansion [and]
    //   Pi is not a pack expansion, template argument deduction fails.
    if (Args[ArgIdx].isPackExpansion())
      return Sema::TDK_MiscellaneousDeductionFailure;

    // Perform deduction for this Pi/Ai pair.
    if (Sema::TemplateDeductionResult Result
          = DeduceTemplateArguments(S, TemplateParams,
                                    Params[ParamIdx], Args[ArgIdx],
                                    Info, Deduced))
      return Result;

    // Move to the next argument.
    ++ArgIdx;
    continue;
  }

  // The parameter is a pack expansion.

  // C++0x [temp.deduct.type]p9:
  //   If Pi is a pack expansion, then the pattern of Pi is compared with
  //   each remaining argument in the template argument list of A. Each
  //   comparison deduces template arguments for subsequent positions in the
  //   template parameter packs expanded by Pi.
  TemplateArgument Pattern = Params[ParamIdx].getPackExpansionPattern();

  // Prepare to deduce the packs within the pattern.
  PackDeductionScope PackScope(S, TemplateParams, Deduced, Info, Pattern);

  // Keep track of the deduced template arguments for each parameter pack
  // expanded by this pack expansion (the outer index) and for each
  // template argument (the inner SmallVectors).
  for (; hasTemplateArgumentForDeduction(Args, ArgIdx) &&
         PackScope.hasNextElement();
       ++ArgIdx) {
    // Deduce template arguments from the pattern.
    if (Sema::TemplateDeductionResult Result
          = DeduceTemplateArguments(S, TemplateParams, Pattern, Args[ArgIdx],
                                    Info, Deduced))
      return Result;

    PackScope.nextPackElement();
  }

  // Build argument packs for each of the parameter packs expanded by this
  // pack expansion.
  if (auto Result = PackScope.finish())
    return Result;
}

return Sema::TDK_Success;
2354}

2356static Sema::TemplateDeductionResult
2357DeduceTemplateArguments(Sema &S,
                      TemplateParameterList *TemplateParams,
                      const TemplateArgumentList &ParamList,
                      const TemplateArgumentList &ArgList,
                      TemplateDeductionInfo &Info,
                      SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
return DeduceTemplateArguments(S, TemplateParams, ParamList.asArray(),
                               ArgList.asArray(), Info, Deduced,
                               /*NumberOfArgumentsMustMatch*/false);
2366}

2368/// Determine whether two template arguments are the same.
2369static bool isSameTemplateArg(ASTContext &Context,
                            TemplateArgument X,
                            const TemplateArgument &Y,
                            bool PackExpansionMatchesPack = false) {
// If we're checking deduced arguments (X) against original arguments (Y),
// we will have flattened packs to non-expansions in X.
if (PackExpansionMatchesPack && X.isPackExpansion() && !Y.isPackExpansion())
  X = X.getPackExpansionPattern();

if (X.getKind() != Y.getKind())
  return false;

switch (X.getKind()) {
  case TemplateArgument::Null:
    llvm_unreachable("Comparing NULL template argument")::llvm::llvm_unreachable_internal("Comparing NULL template argument"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2383);

  case TemplateArgument::Type:
    return Context.getCanonicalType(X.getAsType()) ==
           Context.getCanonicalType(Y.getAsType());

  case TemplateArgument::Declaration:
    return isSameDeclaration(X.getAsDecl(), Y.getAsDecl());

  case TemplateArgument::NullPtr:
    return Context.hasSameType(X.getNullPtrType(), Y.getNullPtrType());

  case TemplateArgument::Template:
  case TemplateArgument::TemplateExpansion:
    return Context.getCanonicalTemplateName(
                  X.getAsTemplateOrTemplatePattern()).getAsVoidPointer() ==
           Context.getCanonicalTemplateName(
                  Y.getAsTemplateOrTemplatePattern()).getAsVoidPointer();

  case TemplateArgument::Integral:
    return hasSameExtendedValue(X.getAsIntegral(), Y.getAsIntegral());

  case TemplateArgument::Expression: {
    llvm::FoldingSetNodeID XID, YID;
    X.getAsExpr()->Profile(XID, Context, true);
    Y.getAsExpr()->Profile(YID, Context, true);
    return XID == YID;
  }

  case TemplateArgument::Pack:
    if (X.pack_size() != Y.pack_size())
      return false;

    for (TemplateArgument::pack_iterator XP = X.pack_begin(),
                                      XPEnd = X.pack_end(),
                                         YP = Y.pack_begin();
         XP != XPEnd; ++XP, ++YP)
      if (!isSameTemplateArg(Context, *XP, *YP, PackExpansionMatchesPack))
        return false;

    return true;
}

llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2426);
2427}

2429/// Allocate a TemplateArgumentLoc where all locations have
2430/// been initialized to the given location.
2431///
2432/// \param Arg The template argument we are producing template argument
2433/// location information for.
2434///
2435/// \param NTTPType For a declaration template argument, the type of
2436/// the non-type template parameter that corresponds to this template
2437/// argument. Can be null if no type sugar is available to add to the
2438/// type from the template argument.
2439///
2440/// \param Loc The source location to use for the resulting template
2441/// argument.
2442TemplateArgumentLoc
2443Sema::getTrivialTemplateArgumentLoc(const TemplateArgument &Arg,
                                  QualType NTTPType, SourceLocation Loc) {
switch (Arg.getKind()) {
case TemplateArgument::Null:
  llvm_unreachable("Can't get a NULL template argument here")::llvm::llvm_unreachable_internal("Can't get a NULL template argument here"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2447);

case TemplateArgument::Type:
  return TemplateArgumentLoc(
      Arg, Context.getTrivialTypeSourceInfo(Arg.getAsType(), Loc));

case TemplateArgument::Declaration: {
  if (NTTPType.isNull())
    NTTPType = Arg.getParamTypeForDecl();
  Expr *E = BuildExpressionFromDeclTemplateArgument(Arg, NTTPType, Loc)
                .getAs<Expr>();
  return TemplateArgumentLoc(TemplateArgument(E), E);
}

case TemplateArgument::NullPtr: {
  if (NTTPType.isNull())
    NTTPType = Arg.getNullPtrType();
  Expr *E = BuildExpressionFromDeclTemplateArgument(Arg, NTTPType, Loc)
                .getAs<Expr>();
  return TemplateArgumentLoc(TemplateArgument(NTTPType, /*isNullPtr*/true),
                             E);
}

case TemplateArgument::Integral: {
  Expr *E =
      BuildExpressionFromIntegralTemplateArgument(Arg, Loc).getAs<Expr>();
  return TemplateArgumentLoc(TemplateArgument(E), E);
}

  case TemplateArgument::Template:
  case TemplateArgument::TemplateExpansion: {
    NestedNameSpecifierLocBuilder Builder;
    TemplateName Template = Arg.getAsTemplate();
    if (DependentTemplateName *DTN = Template.getAsDependentTemplateName())
      Builder.MakeTrivial(Context, DTN->getQualifier(), Loc);
    else if (QualifiedTemplateName *QTN =
                 Template.getAsQualifiedTemplateName())
      Builder.MakeTrivial(Context, QTN->getQualifier(), Loc);

    if (Arg.getKind() == TemplateArgument::Template)
      return TemplateArgumentLoc(Arg, Builder.getWithLocInContext(Context),
                                 Loc);

    return TemplateArgumentLoc(Arg, Builder.getWithLocInContext(Context),
                               Loc, Loc);
  }

case TemplateArgument::Expression:
  return TemplateArgumentLoc(Arg, Arg.getAsExpr());

case TemplateArgument::Pack:
  return TemplateArgumentLoc(Arg, TemplateArgumentLocInfo());
}

llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2501);
2502}

2504/// Convert the given deduced template argument and add it to the set of
2505/// fully-converted template arguments.
2506static bool
2507ConvertDeducedTemplateArgument(Sema &S, NamedDecl *Param,
                             DeducedTemplateArgument Arg,
                             NamedDecl *Template,
                             TemplateDeductionInfo &Info,
                             bool IsDeduced,
                             SmallVectorImpl<TemplateArgument> &Output) {
auto ConvertArg = [&](DeducedTemplateArgument Arg,
                      unsigned ArgumentPackIndex) {
  // Convert the deduced template argument into a template
  // argument that we can check, almost as if the user had written
  // the template argument explicitly.
  TemplateArgumentLoc ArgLoc =
      S.getTrivialTemplateArgumentLoc(Arg, QualType(), Info.getLocation());

  // Check the template argument, converting it as necessary.
  return S.CheckTemplateArgument(
      Param, ArgLoc, Template, Template->getLocation(),
      Template->getSourceRange().getEnd(), ArgumentPackIndex, Output,
      IsDeduced
          ? (Arg.wasDeducedFromArrayBound() ? Sema::CTAK_DeducedFromArrayBound
                                            : Sema::CTAK_Deduced)
          : Sema::CTAK_Specified);
};

if (Arg.getKind() == TemplateArgument::Pack) {
  // This is a template argument pack, so check each of its arguments against
  // the template parameter.
  SmallVector<TemplateArgument, 2> PackedArgsBuilder;
  for (const auto &P : Arg.pack_elements()) {
    // When converting the deduced template argument, append it to the
    // general output list. We need to do this so that the template argument
    // checking logic has all of the prior template arguments available.
    DeducedTemplateArgument InnerArg(P);
    InnerArg.setDeducedFromArrayBound(Arg.wasDeducedFromArrayBound());
    assert(InnerArg.getKind() != TemplateArgument::Pack &&((InnerArg.getKind() != TemplateArgument::Pack && "deduced nested pack"
) ? static_cast<void> (0) : __assert_fail ("InnerArg.getKind() != TemplateArgument::Pack && \"deduced nested pack\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2542, __PRETTY_FUNCTION__))
           "deduced nested pack")((InnerArg.getKind() != TemplateArgument::Pack && "deduced nested pack"
) ? static_cast<void> (0) : __assert_fail ("InnerArg.getKind() != TemplateArgument::Pack && \"deduced nested pack\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2542, __PRETTY_FUNCTION__));
    if (P.isNull()) {
      // We deduced arguments for some elements of this pack, but not for
      // all of them. This happens if we get a conditionally-non-deduced
      // context in a pack expansion (such as an overload set in one of the
      // arguments).
      S.Diag(Param->getLocation(),
             diag::err_template_arg_deduced_incomplete_pack)
        << Arg << Param;
      return true;
    }
    if (ConvertArg(InnerArg, PackedArgsBuilder.size()))
      return true;

    // Move the converted template argument into our argument pack.
    PackedArgsBuilder.push_back(Output.pop_back_val());
  }

  // If the pack is empty, we still need to substitute into the parameter
  // itself, in case that substitution fails.
  if (PackedArgsBuilder.empty()) {
    LocalInstantiationScope Scope(S);
    TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Output);
    MultiLevelTemplateArgumentList Args(TemplateArgs);

    if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
      Sema::InstantiatingTemplate Inst(S, Template->getLocation(), Template,
                                       NTTP, Output,
                                       Template->getSourceRange());
      if (Inst.isInvalid() ||
          S.SubstType(NTTP->getType(), Args, NTTP->getLocation(),
                      NTTP->getDeclName()).isNull())
        return true;
    } else if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Param)) {
      Sema::InstantiatingTemplate Inst(S, Template->getLocation(), Template,
                                       TTP, Output,
                                       Template->getSourceRange());
      if (Inst.isInvalid() || !S.SubstDecl(TTP, S.CurContext, Args))
        return true;
    }
    // For type parameters, no substitution is ever required.
  }

  // Create the resulting argument pack.
  Output.push_back(
      TemplateArgument::CreatePackCopy(S.Context, PackedArgsBuilder));
  return false;
}

return ConvertArg(Arg, 0);
2592}

2594// FIXME: This should not be a template, but
2595// ClassTemplatePartialSpecializationDecl sadly does not derive from
2596// TemplateDecl.
2597template<typename TemplateDeclT>
2598static Sema::TemplateDeductionResult ConvertDeducedTemplateArguments(
  Sema &S, TemplateDeclT *Template, bool IsDeduced,
  SmallVectorImpl<DeducedTemplateArgument> &Deduced,
  TemplateDeductionInfo &Info, SmallVectorImpl<TemplateArgument> &Builder,
  LocalInstantiationScope *CurrentInstantiationScope = nullptr,
  unsigned NumAlreadyConverted = 0, bool PartialOverloading = false) {
TemplateParameterList *TemplateParams = Template->getTemplateParameters();

for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
  NamedDecl *Param = TemplateParams->getParam(I);

  // C++0x [temp.arg.explicit]p3:
  //    A trailing template parameter pack (14.5.3) not otherwise deduced will
  //    be deduced to an empty sequence of template arguments.
  // FIXME: Where did the word "trailing" come from?
  if (Deduced[I].isNull() && Param->isTemplateParameterPack()) {
    if (auto Result = PackDeductionScope(S, TemplateParams, Deduced, Info, I)
                          .finish(/*TreatNoDeductionsAsNonDeduced*/false))
      return Result;
  }

  if (!Deduced[I].isNull()) {
    if (I < NumAlreadyConverted) {
      // We may have had explicitly-specified template arguments for a
      // template parameter pack (that may or may not have been extended
      // via additional deduced arguments).
      if (Param->isParameterPack() && CurrentInstantiationScope &&
          CurrentInstantiationScope->getPartiallySubstitutedPack() == Param) {
        // Forget the partially-substituted pack; its substitution is now
        // complete.
        CurrentInstantiationScope->ResetPartiallySubstitutedPack();
        // We still need to check the argument in case it was extended by
        // deduction.
      } else {
        // We have already fully type-checked and converted this
        // argument, because it was explicitly-specified. Just record the
        // presence of this argument.
        Builder.push_back(Deduced[I]);
        continue;
      }
    }

    // We may have deduced this argument, so it still needs to be
    // checked and converted.
    if (ConvertDeducedTemplateArgument(S, Param, Deduced[I], Template, Info,
                                       IsDeduced, Builder)) {
      Info.Param = makeTemplateParameter(Param);
      // FIXME: These template arguments are temporary. Free them!
      Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder));
      return Sema::TDK_SubstitutionFailure;
    }

    continue;
  }

  // Substitute into the default template argument, if available.
  bool HasDefaultArg = false;
  TemplateDecl *TD = dyn_cast<TemplateDecl>(Template);
  if (!TD) {
    assert(isa<ClassTemplatePartialSpecializationDecl>(Template) ||((isa<ClassTemplatePartialSpecializationDecl>(Template)
 || isa<VarTemplatePartialSpecializationDecl>(Template)
) ? static_cast<void> (0) : __assert_fail ("isa<ClassTemplatePartialSpecializationDecl>(Template) || isa<VarTemplatePartialSpecializationDecl>(Template)"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2658, __PRETTY_FUNCTION__))
           isa<VarTemplatePartialSpecializationDecl>(Template))((isa<ClassTemplatePartialSpecializationDecl>(Template)
 || isa<VarTemplatePartialSpecializationDecl>(Template)
) ? static_cast<void> (0) : __assert_fail ("isa<ClassTemplatePartialSpecializationDecl>(Template) || isa<VarTemplatePartialSpecializationDecl>(Template)"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2658, __PRETTY_FUNCTION__));
    return Sema::TDK_Incomplete;
  }

  TemplateArgumentLoc DefArg = S.SubstDefaultTemplateArgumentIfAvailable(
      TD, TD->getLocation(), TD->getSourceRange().getEnd(), Param, Builder,
      HasDefaultArg);

  // If there was no default argument, deduction is incomplete.
  if (DefArg.getArgument().isNull()) {
    Info.Param = makeTemplateParameter(
        const_cast<NamedDecl *>(TemplateParams->getParam(I)));
    Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder));
    if (PartialOverloading) break;

    return HasDefaultArg ? Sema::TDK_SubstitutionFailure
                         : Sema::TDK_Incomplete;
  }

  // Check whether we can actually use the default argument.
  if (S.CheckTemplateArgument(Param, DefArg, TD, TD->getLocation(),
                              TD->getSourceRange().getEnd(), 0, Builder,
                              Sema::CTAK_Specified)) {
    Info.Param = makeTemplateParameter(
                       const_cast<NamedDecl *>(TemplateParams->getParam(I)));
    // FIXME: These template arguments are temporary. Free them!
    Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder));
    return Sema::TDK_SubstitutionFailure;
  }

  // If we get here, we successfully used the default template argument.
}

return Sema::TDK_Success;
2692}

2694static DeclContext *getAsDeclContextOrEnclosing(Decl *D) {
if (auto *DC = dyn_cast<DeclContext>(D))
  return DC;
return D->getDeclContext();
2698}

2700template<typename T> struct IsPartialSpecialization {
static constexpr bool value = false;
2702};
2703template<>
2704struct IsPartialSpecialization<ClassTemplatePartialSpecializationDecl> {
static constexpr bool value = true;
2706};
2707template<>
2708struct IsPartialSpecialization<VarTemplatePartialSpecializationDecl> {
static constexpr bool value = true;
2710};

2712/// Complete template argument deduction for a partial specialization.
2713template <typename T>
2714static typename std::enable_if<IsPartialSpecialization<T>::value,
                             Sema::TemplateDeductionResult>::type
2716FinishTemplateArgumentDeduction(
  Sema &S, T *Partial, bool IsPartialOrdering,
  const TemplateArgumentList &TemplateArgs,
  SmallVectorImpl<DeducedTemplateArgument> &Deduced,
  TemplateDeductionInfo &Info) {
// Unevaluated SFINAE context.
EnterExpressionEvaluationContext Unevaluated(
    S, Sema::ExpressionEvaluationContext::Unevaluated);
Sema::SFINAETrap Trap(S);

Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(Partial));

// C++ [temp.deduct.type]p2:
//   [...] or if any template argument remains neither deduced nor
//   explicitly specified, template argument deduction fails.
SmallVector<TemplateArgument, 4> Builder;
if (auto Result = ConvertDeducedTemplateArguments(
        S, Partial, IsPartialOrdering, Deduced, Info, Builder))
  return Result;

// Form the template argument list from the deduced template arguments.
TemplateArgumentList *DeducedArgumentList
  = TemplateArgumentList::CreateCopy(S.Context, Builder);

Info.reset(DeducedArgumentList);

// Substitute the deduced template arguments into the template
// arguments of the class template partial specialization, and
// verify that the instantiated template arguments are both valid
// and are equivalent to the template arguments originally provided
// to the class template.
LocalInstantiationScope InstScope(S);
auto *Template = Partial->getSpecializedTemplate();
const ASTTemplateArgumentListInfo *PartialTemplArgInfo =
    Partial->getTemplateArgsAsWritten();
const TemplateArgumentLoc *PartialTemplateArgs =
    PartialTemplArgInfo->getTemplateArgs();

TemplateArgumentListInfo InstArgs(PartialTemplArgInfo->LAngleLoc,
                                  PartialTemplArgInfo->RAngleLoc);

if (S.Subst(PartialTemplateArgs, PartialTemplArgInfo->NumTemplateArgs,
            InstArgs, MultiLevelTemplateArgumentList(*DeducedArgumentList))) {
  unsigned ArgIdx = InstArgs.size(), ParamIdx = ArgIdx;
  if (ParamIdx >= Partial->getTemplateParameters()->size())
    ParamIdx = Partial->getTemplateParameters()->size() - 1;

  Decl *Param = const_cast<NamedDecl *>(
      Partial->getTemplateParameters()->getParam(ParamIdx));
  Info.Param = makeTemplateParameter(Param);
  Info.FirstArg = PartialTemplateArgs[ArgIdx].getArgument();
  return Sema::TDK_SubstitutionFailure;
}

SmallVector<TemplateArgument, 4> ConvertedInstArgs;
if (S.CheckTemplateArgumentList(Template, Partial->getLocation(), InstArgs,
                                false, ConvertedInstArgs))
  return Sema::TDK_SubstitutionFailure;

TemplateParameterList *TemplateParams = Template->getTemplateParameters();
for (unsigned I = 0, E = TemplateParams->size(); I != E; ++I) {
  TemplateArgument InstArg = ConvertedInstArgs.data()[I];
  if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg)) {
    Info.Param = makeTemplateParameter(TemplateParams->getParam(I));
    Info.FirstArg = TemplateArgs[I];
    Info.SecondArg = InstArg;
    return Sema::TDK_NonDeducedMismatch;
  }
}

if (Trap.hasErrorOccurred())
  return Sema::TDK_SubstitutionFailure;

return Sema::TDK_Success;
2790}

2792/// Complete template argument deduction for a class or variable template,
2793/// when partial ordering against a partial specialization.
2794// FIXME: Factor out duplication with partial specialization version above.
2795static Sema::TemplateDeductionResult FinishTemplateArgumentDeduction(
  Sema &S, TemplateDecl *Template, bool PartialOrdering,
  const TemplateArgumentList &TemplateArgs,
  SmallVectorImpl<DeducedTemplateArgument> &Deduced,
  TemplateDeductionInfo &Info) {
// Unevaluated SFINAE context.
EnterExpressionEvaluationContext Unevaluated(
    S, Sema::ExpressionEvaluationContext::Unevaluated);
Sema::SFINAETrap Trap(S);

Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(Template));

// C++ [temp.deduct.type]p2:
//   [...] or if any template argument remains neither deduced nor
//   explicitly specified, template argument deduction fails.
SmallVector<TemplateArgument, 4> Builder;
if (auto Result = ConvertDeducedTemplateArguments(
        S, Template, /*IsDeduced*/PartialOrdering, Deduced, Info, Builder))
  return Result;

// Check that we produced the correct argument list.
TemplateParameterList *TemplateParams = Template->getTemplateParameters();
for (unsigned I = 0, E = TemplateParams->size(); I != E; ++I) {
  TemplateArgument InstArg = Builder[I];
  if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg,
                         /*PackExpansionMatchesPack*/true)) {
    Info.Param = makeTemplateParameter(TemplateParams->getParam(I));
    Info.FirstArg = TemplateArgs[I];
    Info.SecondArg = InstArg;
    return Sema::TDK_NonDeducedMismatch;
  }
}

if (Trap.hasErrorOccurred())
  return Sema::TDK_SubstitutionFailure;

return Sema::TDK_Success;
2832}


2835/// Perform template argument deduction to determine whether
2836/// the given template arguments match the given class template
2837/// partial specialization per C++ [temp.class.spec.match].
2838Sema::TemplateDeductionResult
2839Sema::DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
                            const TemplateArgumentList &TemplateArgs,
                            TemplateDeductionInfo &Info) {
if (Partial->isInvalidDecl())
  return TDK_Invalid;

// C++ [temp.class.spec.match]p2:
//   A partial specialization matches a given actual template
//   argument list if the template arguments of the partial
//   specialization can be deduced from the actual template argument
//   list (14.8.2).

// Unevaluated SFINAE context.
EnterExpressionEvaluationContext Unevaluated(
    *this, Sema::ExpressionEvaluationContext::Unevaluated);
SFINAETrap Trap(*this);

SmallVector<DeducedTemplateArgument, 4> Deduced;
Deduced.resize(Partial->getTemplateParameters()->size());
if (TemplateDeductionResult Result
      = ::DeduceTemplateArguments(*this,
                                  Partial->getTemplateParameters(),
                                  Partial->getTemplateArgs(),
                                  TemplateArgs, Info, Deduced))
  return Result;

SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end());
InstantiatingTemplate Inst(*this, Info.getLocation(), Partial, DeducedArgs,
                           Info);
if (Inst.isInvalid())
  return TDK_InstantiationDepth;

if (Trap.hasErrorOccurred())
  return Sema::TDK_SubstitutionFailure;

return ::FinishTemplateArgumentDeduction(
    *this, Partial, /*IsPartialOrdering=*/false, TemplateArgs, Deduced, Info);
2876}

2878/// Perform template argument deduction to determine whether
2879/// the given template arguments match the given variable template
2880/// partial specialization per C++ [temp.class.spec.match].
2881Sema::TemplateDeductionResult
2882Sema::DeduceTemplateArguments(VarTemplatePartialSpecializationDecl *Partial,
                            const TemplateArgumentList &TemplateArgs,
                            TemplateDeductionInfo &Info) {
if (Partial->isInvalidDecl())
  return TDK_Invalid;

// C++ [temp.class.spec.match]p2:
//   A partial specialization matches a given actual template
//   argument list if the template arguments of the partial
//   specialization can be deduced from the actual template argument
//   list (14.8.2).

// Unevaluated SFINAE context.
EnterExpressionEvaluationContext Unevaluated(
    *this, Sema::ExpressionEvaluationContext::Unevaluated);
SFINAETrap Trap(*this);

SmallVector<DeducedTemplateArgument, 4> Deduced;
Deduced.resize(Partial->getTemplateParameters()->size());
if (TemplateDeductionResult Result = ::DeduceTemplateArguments(
        *this, Partial->getTemplateParameters(), Partial->getTemplateArgs(),
        TemplateArgs, Info, Deduced))
  return Result;

SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end());
InstantiatingTemplate Inst(*this, Info.getLocation(), Partial, DeducedArgs,
                           Info);
if (Inst.isInvalid())
  return TDK_InstantiationDepth;

if (Trap.hasErrorOccurred())
  return Sema::TDK_SubstitutionFailure;

return ::FinishTemplateArgumentDeduction(
    *this, Partial, /*IsPartialOrdering=*/false, TemplateArgs, Deduced, Info);
2917}

2919/// Determine whether the given type T is a simple-template-id type.
2920static bool isSimpleTemplateIdType(QualType T) {
if (const TemplateSpecializationType *Spec36.1
'Spec' is non-null
1
'Spec' is non-null

36.1	'Spec' is non-null

←

Taking true branch

→

2922 = T->getAs<TemplateSpecializationType>())

←

Assuming the object is a 'TemplateSpecializationType'

→

2923 return Spec->getTemplateName().getAsTemplateDecl() != nullptr;

←

Assuming the condition is false

→

←

Returning zero, which participates in a condition later

→

2924 2925 // C++17 [temp.local]p2: 2926 // the injected-class-name [...] is equivalent to the template-name followed 2927 // by the template-arguments of the class template specialization or partial 2928 // specialization enclosed in <> 2929 // ... which means it's equivalent to a simple-template-id. 2930 // 2931 // This only arises during class template argument deduction for a copy 2932 // deduction candidate, where it permits slicing. 2933 if (T->getAs<InjectedClassNameType>()) 2934 return true; 2935 2936 return false; 2937} 2938 2939/// Substitute the explicitly-provided template arguments into the 2940/// given function template according to C++ [temp.arg.explicit]. 2941/// 2942/// \param FunctionTemplate the function template into which the explicit 2943/// template arguments will be substituted. 2944/// 2945/// \param ExplicitTemplateArgs the explicitly-specified template 2946/// arguments. 2947/// 2948/// \param Deduced the deduced template arguments, which will be populated 2949/// with the converted and checked explicit template arguments. 2950/// 2951/// \param ParamTypes will be populated with the instantiated function 2952/// parameters. 2953/// 2954/// \param FunctionType if non-NULL, the result type of the function template 2955/// will also be instantiated and the pointed-to value will be updated with 2956/// the instantiated function type. 2957/// 2958/// \param Info if substitution fails for any reason, this object will be 2959/// populated with more information about the failure. 2960/// 2961/// \returns TDK_Success if substitution was successful, or some failure 2962/// condition. 2963Sema::TemplateDeductionResult 2964Sema::SubstituteExplicitTemplateArguments( 2965 FunctionTemplateDecl *FunctionTemplate, 2966 TemplateArgumentListInfo &ExplicitTemplateArgs, 2967 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 2968 SmallVectorImpl<QualType> &ParamTypes, 2969 QualType *FunctionType, 2970 TemplateDeductionInfo &Info) { 2971 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 2972 TemplateParameterList *TemplateParams 2973 = FunctionTemplate->getTemplateParameters(); 2974 2975 if (ExplicitTemplateArgs.size() == 0) { 2976 // No arguments to substitute; just copy over the parameter types and 2977 // fill in the function type. 2978 for (auto P : Function->parameters()) 2979 ParamTypes.push_back(P->getType()); 2980 2981 if (FunctionType) 2982 *FunctionType = Function->getType(); 2983 return TDK_Success; 2984 } 2985 2986 // Unevaluated SFINAE context. 2987 EnterExpressionEvaluationContext Unevaluated( 2988 *this, Sema::ExpressionEvaluationContext::Unevaluated); 2989 SFINAETrap Trap(*this); 2990 2991 // C++ [temp.arg.explicit]p3: 2992 // Template arguments that are present shall be specified in the 2993 // declaration order of their corresponding template-parameters. The 2994 // template argument list shall not specify more template-arguments than 2995 // there are corresponding template-parameters. 2996 SmallVector<TemplateArgument, 4> Builder; 2997 2998 // Enter a new template instantiation context where we check the 2999 // explicitly-specified template arguments against this function template, 3000 // and then substitute them into the function parameter types. 3001 SmallVector<TemplateArgument, 4> DeducedArgs; 3002 InstantiatingTemplate Inst( 3003 *this, Info.getLocation(), FunctionTemplate, DeducedArgs, 3004 CodeSynthesisContext::ExplicitTemplateArgumentSubstitution, Info); 3005 if (Inst.isInvalid()) 3006 return TDK_InstantiationDepth; 3007 3008 if (CheckTemplateArgumentList(FunctionTemplate, SourceLocation(), 3009 ExplicitTemplateArgs, true, Builder, false) || 3010 Trap.hasErrorOccurred()) { 3011 unsigned Index = Builder.size(); 3012 if (Index >= TemplateParams->size()) 3013 return TDK_SubstitutionFailure; 3014 Info.Param = makeTemplateParameter(TemplateParams->getParam(Index)); 3015 return TDK_InvalidExplicitArguments; 3016 } 3017 3018 // Form the template argument list from the explicitly-specified 3019 // template arguments. 3020 TemplateArgumentList *ExplicitArgumentList 3021 = TemplateArgumentList::CreateCopy(Context, Builder); 3022 Info.setExplicitArgs(ExplicitArgumentList); 3023 3024 // Template argument deduction and the final substitution should be 3025 // done in the context of the templated declaration. Explicit 3026 // argument substitution, on the other hand, needs to happen in the 3027 // calling context. 3028 ContextRAII SavedContext(*this, FunctionTemplate->getTemplatedDecl()); 3029 3030 // If we deduced template arguments for a template parameter pack, 3031 // note that the template argument pack is partially substituted and record 3032 // the explicit template arguments. They'll be used as part of deduction 3033 // for this template parameter pack. 3034 unsigned PartiallySubstitutedPackIndex = -1u; 3035 if (!Builder.empty()) { 3036 const TemplateArgument &Arg = Builder.back(); 3037 if (Arg.getKind() == TemplateArgument::Pack) { 3038 auto *Param = TemplateParams->getParam(Builder.size() - 1); 3039 // If this is a fully-saturated fixed-size pack, it should be 3040 // fully-substituted, not partially-substituted. 3041 Optional<unsigned> Expansions = getExpandedPackSize(Param); 3042 if (!Expansions || Arg.pack_size() < *Expansions) { 3043 PartiallySubstitutedPackIndex = Builder.size() - 1; 3044 CurrentInstantiationScope->SetPartiallySubstitutedPack( 3045 Param, Arg.pack_begin(), Arg.pack_size()); 3046 } 3047 } 3048 } 3049 3050 const FunctionProtoType *Proto 3051 = Function->getType()->getAs<FunctionProtoType>(); 3052 assert(Proto && "Function template does not have a prototype?")((Proto && "Function template does not have a prototype?"
) ? static_cast<void> (0) : __assert_fail ("Proto && \"Function template does not have a prototype?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3052, __PRETTY_FUNCTION__)); 3053 3054 // Isolate our substituted parameters from our caller. 3055 LocalInstantiationScope InstScope(*this, /*MergeWithOuterScope*/true); 3056 3057 ExtParameterInfoBuilder ExtParamInfos; 3058 3059 // Instantiate the types of each of the function parameters given the 3060 // explicitly-specified template arguments. If the function has a trailing 3061 // return type, substitute it after the arguments to ensure we substitute 3062 // in lexical order. 3063 if (Proto->hasTrailingReturn()) { 3064 if (SubstParmTypes(Function->getLocation(), Function->parameters(), 3065 Proto->getExtParameterInfosOrNull(), 3066 MultiLevelTemplateArgumentList(*ExplicitArgumentList), 3067 ParamTypes, /*params*/ nullptr, ExtParamInfos)) 3068 return TDK_SubstitutionFailure; 3069 } 3070 3071 // Instantiate the return type. 3072 QualType ResultType; 3073 { 3074 // C++11 [expr.prim.general]p3: 3075 // If a declaration declares a member function or member function 3076 // template of a class X, the expression this is a prvalue of type 3077 // "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq 3078 // and the end of the function-definition, member-declarator, or 3079 // declarator. 3080 Qualifiers ThisTypeQuals; 3081 CXXRecordDecl *ThisContext = nullptr; 3082 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3083 ThisContext = Method->getParent(); 3084 ThisTypeQuals = Method->getMethodQualifiers(); 3085 } 3086 3087 CXXThisScopeRAII ThisScope(*this, ThisContext, ThisTypeQuals, 3088 getLangOpts().CPlusPlus11); 3089 3090 ResultType = 3091 SubstType(Proto->getReturnType(), 3092 MultiLevelTemplateArgumentList(*ExplicitArgumentList), 3093 Function->getTypeSpecStartLoc(), Function->getDeclName()); 3094 if (ResultType.isNull() || Trap.hasErrorOccurred()) 3095 return TDK_SubstitutionFailure; 3096 // CUDA: Kernel function must have 'void' return type. 3097 if (getLangOpts().CUDA) 3098 if (Function->hasAttr<CUDAGlobalAttr>() && !ResultType->isVoidType()) { 3099 Diag(Function->getLocation(), diag::err_kern_type_not_void_return) 3100 << Function->getType() << Function->getSourceRange(); 3101 return TDK_SubstitutionFailure; 3102 } 3103 } 3104 3105 // Instantiate the types of each of the function parameters given the 3106 // explicitly-specified template arguments if we didn't do so earlier. 3107 if (!Proto->hasTrailingReturn() && 3108 SubstParmTypes(Function->getLocation(), Function->parameters(), 3109 Proto->getExtParameterInfosOrNull(), 3110 MultiLevelTemplateArgumentList(*ExplicitArgumentList), 3111 ParamTypes, /*params*/ nullptr, ExtParamInfos)) 3112 return TDK_SubstitutionFailure; 3113 3114 if (FunctionType) { 3115 auto EPI = Proto->getExtProtoInfo(); 3116 EPI.ExtParameterInfos = ExtParamInfos.getPointerOrNull(ParamTypes.size()); 3117 3118 // In C++1z onwards, exception specifications are part of the function type, 3119 // so substitution into the type must also substitute into the exception 3120 // specification. 3121 SmallVector<QualType, 4> ExceptionStorage; 3122 if (getLangOpts().CPlusPlus17 && 3123 SubstExceptionSpec( 3124 Function->getLocation(), EPI.ExceptionSpec, ExceptionStorage, 3125 MultiLevelTemplateArgumentList(*ExplicitArgumentList))) 3126 return TDK_SubstitutionFailure; 3127 3128 *FunctionType = BuildFunctionType(ResultType, ParamTypes, 3129 Function->getLocation(), 3130 Function->getDeclName(), 3131 EPI); 3132 if (FunctionType->isNull() || Trap.hasErrorOccurred()) 3133 return TDK_SubstitutionFailure; 3134 } 3135 3136 // C++ [temp.arg.explicit]p2: 3137 // Trailing template arguments that can be deduced (14.8.2) may be 3138 // omitted from the list of explicit template-arguments. If all of the 3139 // template arguments can be deduced, they may all be omitted; in this 3140 // case, the empty template argument list <> itself may also be omitted. 3141 // 3142 // Take all of the explicitly-specified arguments and put them into 3143 // the set of deduced template arguments. The partially-substituted 3144 // parameter pack, however, will be set to NULL since the deduction 3145 // mechanism handles the partially-substituted argument pack directly. 3146 Deduced.reserve(TemplateParams->size()); 3147 for (unsigned I = 0, N = ExplicitArgumentList->size(); I != N; ++I) { 3148 const TemplateArgument &Arg = ExplicitArgumentList->get(I); 3149 if (I == PartiallySubstitutedPackIndex) 3150 Deduced.push_back(DeducedTemplateArgument()); 3151 else 3152 Deduced.push_back(Arg); 3153 } 3154 3155 return TDK_Success; 3156} 3157 3158/// Check whether the deduced argument type for a call to a function 3159/// template matches the actual argument type per C++ [temp.deduct.call]p4. 3160static Sema::TemplateDeductionResult 3161CheckOriginalCallArgDeduction(Sema &S, TemplateDeductionInfo &Info, 3162 Sema::OriginalCallArg OriginalArg, 3163 QualType DeducedA) { 3164 ASTContext &Context = S.Context; 3165 3166 auto Failed = [&]() -> Sema::TemplateDeductionResult { 3167 Info.FirstArg = TemplateArgument(DeducedA); 3168 Info.SecondArg = TemplateArgument(OriginalArg.OriginalArgType); 3169 Info.CallArgIndex = OriginalArg.ArgIdx; 3170 return OriginalArg.DecomposedParam ? Sema::TDK_DeducedMismatchNested 3171 : Sema::TDK_DeducedMismatch; 3172 }; 3173 3174 QualType A = OriginalArg.OriginalArgType; 3175 QualType OriginalParamType = OriginalArg.OriginalParamType; 3176 3177 // Check for type equality (top-level cv-qualifiers are ignored). 3178 if (Context.hasSameUnqualifiedType(A, DeducedA)) 3179 return Sema::TDK_Success; 3180 3181 // Strip off references on the argument types; they aren't needed for 3182 // the following checks. 3183 if (const ReferenceType *DeducedARef = DeducedA->getAs<ReferenceType>()) 3184 DeducedA = DeducedARef->getPointeeType(); 3185 if (const ReferenceType *ARef = A->getAs<ReferenceType>()) 3186 A = ARef->getPointeeType(); 3187 3188 // C++ [temp.deduct.call]p4: 3189 // [...] However, there are three cases that allow a difference: 3190 // - If the original P is a reference type, the deduced A (i.e., the 3191 // type referred to by the reference) can be more cv-qualified than 3192 // the transformed A. 3193 if (const ReferenceType *OriginalParamRef 3194 = OriginalParamType->getAs<ReferenceType>()) { 3195 // We don't want to keep the reference around any more. 3196 OriginalParamType = OriginalParamRef->getPointeeType(); 3197 3198 // FIXME: Resolve core issue (no number yet): if the original P is a 3199 // reference type and the transformed A is function type "noexcept F", 3200 // the deduced A can be F. 3201 QualType Tmp; 3202 if (A->isFunctionType() && S.IsFunctionConversion(A, DeducedA, Tmp)) 3203 return Sema::TDK_Success; 3204 3205 Qualifiers AQuals = A.getQualifiers(); 3206 Qualifiers DeducedAQuals = DeducedA.getQualifiers(); 3207 3208 // Under Objective-C++ ARC, the deduced type may have implicitly 3209 // been given strong or (when dealing with a const reference) 3210 // unsafe_unretained lifetime. If so, update the original 3211 // qualifiers to include this lifetime. 3212 if (S.getLangOpts().ObjCAutoRefCount && 3213 ((DeducedAQuals.getObjCLifetime() == Qualifiers::OCL_Strong && 3214 AQuals.getObjCLifetime() == Qualifiers::OCL_None) || 3215 (DeducedAQuals.hasConst() && 3216 DeducedAQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone))) { 3217 AQuals.setObjCLifetime(DeducedAQuals.getObjCLifetime()); 3218 } 3219 3220 if (AQuals == DeducedAQuals) { 3221 // Qualifiers match; there's nothing to do. 3222 } else if (!DeducedAQuals.compatiblyIncludes(AQuals)) { 3223 return Failed(); 3224 } else { 3225 // Qualifiers are compatible, so have the argument type adopt the 3226 // deduced argument type's qualifiers as if we had performed the 3227 // qualification conversion. 3228 A = Context.getQualifiedType(A.getUnqualifiedType(), DeducedAQuals); 3229 } 3230 } 3231 3232 // - The transformed A can be another pointer or pointer to member 3233 // type that can be converted to the deduced A via a function pointer 3234 // conversion and/or a qualification conversion. 3235 // 3236 // Also allow conversions which merely strip __attribute__((noreturn)) from 3237 // function types (recursively). 3238 bool ObjCLifetimeConversion = false; 3239 QualType ResultTy; 3240 if ((A->isAnyPointerType() || A->isMemberPointerType()) && 3241 (S.IsQualificationConversion(A, DeducedA, false, 3242 ObjCLifetimeConversion) || 3243 S.IsFunctionConversion(A, DeducedA, ResultTy))) 3244 return Sema::TDK_Success; 3245 3246 // - If P is a class and P has the form simple-template-id, then the 3247 // transformed A can be a derived class of the deduced A. [...] 3248 // [...] Likewise, if P is a pointer to a class of the form 3249 // simple-template-id, the transformed A can be a pointer to a 3250 // derived class pointed to by the deduced A. 3251 if (const PointerType *OriginalParamPtr 3252 = OriginalParamType->getAs<PointerType>()) { 3253 if (const PointerType *DeducedAPtr = DeducedA->getAs<PointerType>()) { 3254 if (const PointerType *APtr = A->getAs<PointerType>()) { 3255 if (A->getPointeeType()->isRecordType()) { 3256 OriginalParamType = OriginalParamPtr->getPointeeType(); 3257 DeducedA = DeducedAPtr->getPointeeType(); 3258 A = APtr->getPointeeType(); 3259 } 3260 } 3261 } 3262 } 3263 3264 if (Context.hasSameUnqualifiedType(A, DeducedA)) 3265 return Sema::TDK_Success; 3266 3267 if (A->isRecordType() && isSimpleTemplateIdType(OriginalParamType) && 3268 S.IsDerivedFrom(Info.getLocation(), A, DeducedA)) 3269 return Sema::TDK_Success; 3270 3271 return Failed(); 3272} 3273 3274/// Find the pack index for a particular parameter index in an instantiation of 3275/// a function template with specific arguments. 3276/// 3277/// \return The pack index for whichever pack produced this parameter, or -1 3278/// if this was not produced by a parameter. Intended to be used as the 3279/// ArgumentPackSubstitutionIndex for further substitutions. 3280// FIXME: We should track this in OriginalCallArgs so we don't need to 3281// reconstruct it here. 3282static unsigned getPackIndexForParam(Sema &S, 3283 FunctionTemplateDecl *FunctionTemplate, 3284 const MultiLevelTemplateArgumentList &Args, 3285 unsigned ParamIdx) { 3286 unsigned Idx = 0; 3287 for (auto *PD : FunctionTemplate->getTemplatedDecl()->parameters()) { 3288 if (PD->isParameterPack()) { 3289 unsigned NumExpansions = 3290 S.getNumArgumentsInExpansion(PD->getType(), Args).getValueOr(1); 3291 if (Idx + NumExpansions > ParamIdx) 3292 return ParamIdx - Idx; 3293 Idx += NumExpansions; 3294 } else { 3295 if (Idx == ParamIdx) 3296 return -1; // Not a pack expansion 3297 ++Idx; 3298 } 3299 } 3300 3301 llvm_unreachable("parameter index would not be produced from template")::llvm::llvm_unreachable_internal("parameter index would not be produced from template"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3301); 3302} 3303 3304/// Finish template argument deduction for a function template, 3305/// checking the deduced template arguments for completeness and forming 3306/// the function template specialization. 3307/// 3308/// \param OriginalCallArgs If non-NULL, the original call arguments against 3309/// which the deduced argument types should be compared. 3310Sema::TemplateDeductionResult Sema::FinishTemplateArgumentDeduction( 3311 FunctionTemplateDecl *FunctionTemplate, 3312 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3313 unsigned NumExplicitlySpecified, FunctionDecl *&Specialization, 3314 TemplateDeductionInfo &Info, 3315 SmallVectorImpl<OriginalCallArg> const *OriginalCallArgs, 3316 bool PartialOverloading, llvm::function_ref<bool()> CheckNonDependent) { 3317 // Unevaluated SFINAE context. 3318 EnterExpressionEvaluationContext Unevaluated( 3319 *this, Sema::ExpressionEvaluationContext::Unevaluated); 3320 SFINAETrap Trap(*this); 3321 3322 // Enter a new template instantiation context while we instantiate the 3323 // actual function declaration. 3324 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end()); 3325 InstantiatingTemplate Inst( 3326 *this, Info.getLocation(), FunctionTemplate, DeducedArgs, 3327 CodeSynthesisContext::DeducedTemplateArgumentSubstitution, Info); 3328 if (Inst.isInvalid()) 3329 return TDK_InstantiationDepth; 3330 3331 ContextRAII SavedContext(*this, FunctionTemplate->getTemplatedDecl()); 3332 3333 // C++ [temp.deduct.type]p2: 3334 // [...] or if any template argument remains neither deduced nor 3335 // explicitly specified, template argument deduction fails. 3336 SmallVector<TemplateArgument, 4> Builder; 3337 if (auto Result = ConvertDeducedTemplateArguments( 3338 *this, FunctionTemplate, /*IsDeduced*/true, Deduced, Info, Builder, 3339 CurrentInstantiationScope, NumExplicitlySpecified, 3340 PartialOverloading)) 3341 return Result; 3342 3343 // C++ [temp.deduct.call]p10: [DR1391] 3344 // If deduction succeeds for all parameters that contain 3345 // template-parameters that participate in template argument deduction, 3346 // and all template arguments are explicitly specified, deduced, or 3347 // obtained from default template arguments, remaining parameters are then 3348 // compared with the corresponding arguments. For each remaining parameter 3349 // P with a type that was non-dependent before substitution of any 3350 // explicitly-specified template arguments, if the corresponding argument 3351 // A cannot be implicitly converted to P, deduction fails. 3352 if (CheckNonDependent()) 3353 return TDK_NonDependentConversionFailure; 3354 3355 // Form the template argument list from the deduced template arguments. 3356 TemplateArgumentList *DeducedArgumentList 3357 = TemplateArgumentList::CreateCopy(Context, Builder); 3358 Info.reset(DeducedArgumentList); 3359 3360 // Substitute the deduced template arguments into the function template 3361 // declaration to produce the function template specialization. 3362 DeclContext *Owner = FunctionTemplate->getDeclContext(); 3363 if (FunctionTemplate->getFriendObjectKind()) 3364 Owner = FunctionTemplate->getLexicalDeclContext(); 3365 MultiLevelTemplateArgumentList SubstArgs(*DeducedArgumentList); 3366 Specialization = cast_or_null<FunctionDecl>( 3367 SubstDecl(FunctionTemplate->getTemplatedDecl(), Owner, SubstArgs)); 3368 if (!Specialization || Specialization->isInvalidDecl()) 3369 return TDK_SubstitutionFailure; 3370 3371 assert(Specialization->getPrimaryTemplate()->getCanonicalDecl() ==((Specialization->getPrimaryTemplate()->getCanonicalDecl
() == FunctionTemplate->getCanonicalDecl()) ? static_cast<
void> (0) : __assert_fail ("Specialization->getPrimaryTemplate()->getCanonicalDecl() == FunctionTemplate->getCanonicalDecl()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3372, __PRETTY_FUNCTION__)) 3372 FunctionTemplate->getCanonicalDecl())((Specialization->getPrimaryTemplate()->getCanonicalDecl
() == FunctionTemplate->getCanonicalDecl()) ? static_cast<
void> (0) : __assert_fail ("Specialization->getPrimaryTemplate()->getCanonicalDecl() == FunctionTemplate->getCanonicalDecl()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3372, __PRETTY_FUNCTION__)); 3373 3374 // If the template argument list is owned by the function template 3375 // specialization, release it. 3376 if (Specialization->getTemplateSpecializationArgs() == DeducedArgumentList && 3377 !Trap.hasErrorOccurred()) 3378 Info.take(); 3379 3380 // There may have been an error that did not prevent us from constructing a 3381 // declaration. Mark the declaration invalid and return with a substitution 3382 // failure. 3383 if (Trap.hasErrorOccurred()) { 3384 Specialization->setInvalidDecl(true); 3385 return TDK_SubstitutionFailure; 3386 } 3387 3388 if (OriginalCallArgs) { 3389 // C++ [temp.deduct.call]p4: 3390 // In general, the deduction process attempts to find template argument 3391 // values that will make the deduced A identical to A (after the type A 3392 // is transformed as described above). [...] 3393 llvm::SmallDenseMap<std::pair<unsigned, QualType>, QualType> DeducedATypes; 3394 for (unsigned I = 0, N = OriginalCallArgs->size(); I != N; ++I) { 3395 OriginalCallArg OriginalArg = (*OriginalCallArgs)[I]; 3396 3397 auto ParamIdx = OriginalArg.ArgIdx; 3398 if (ParamIdx >= Specialization->getNumParams()) 3399 // FIXME: This presumably means a pack ended up smaller than we 3400 // expected while deducing. Should this not result in deduction 3401 // failure? Can it even happen? 3402 continue; 3403 3404 QualType DeducedA; 3405 if (!OriginalArg.DecomposedParam) { 3406 // P is one of the function parameters, just look up its substituted 3407 // type. 3408 DeducedA = Specialization->getParamDecl(ParamIdx)->getType(); 3409 } else { 3410 // P is a decomposed element of a parameter corresponding to a 3411 // braced-init-list argument. Substitute back into P to find the 3412 // deduced A. 3413 QualType &CacheEntry = 3414 DeducedATypes[{ParamIdx, OriginalArg.OriginalParamType}]; 3415 if (CacheEntry.isNull()) { 3416 ArgumentPackSubstitutionIndexRAII PackIndex( 3417 *this, getPackIndexForParam(*this, FunctionTemplate, SubstArgs, 3418 ParamIdx)); 3419 CacheEntry = 3420 SubstType(OriginalArg.OriginalParamType, SubstArgs, 3421 Specialization->getTypeSpecStartLoc(), 3422 Specialization->getDeclName()); 3423 } 3424 DeducedA = CacheEntry; 3425 } 3426 3427 if (auto TDK = 3428 CheckOriginalCallArgDeduction(*this, Info, OriginalArg, DeducedA)) 3429 return TDK; 3430 } 3431 } 3432 3433 // If we suppressed any diagnostics while performing template argument 3434 // deduction, and if we haven't already instantiated this declaration, 3435 // keep track of these diagnostics. They'll be emitted if this specialization 3436 // is actually used. 3437 if (Info.diag_begin() != Info.diag_end()) { 3438 SuppressedDiagnosticsMap::iterator 3439 Pos = SuppressedDiagnostics.find(Specialization->getCanonicalDecl()); 3440 if (Pos == SuppressedDiagnostics.end()) 3441 SuppressedDiagnostics[Specialization->getCanonicalDecl()] 3442 .append(Info.diag_begin(), Info.diag_end()); 3443 } 3444 3445 return TDK_Success; 3446} 3447 3448/// Gets the type of a function for template-argument-deducton 3449/// purposes when it's considered as part of an overload set. 3450static QualType GetTypeOfFunction(Sema &S, const OverloadExpr::FindResult &R, 3451 FunctionDecl *Fn) { 3452 // We may need to deduce the return type of the function now. 3453 if (S.getLangOpts().CPlusPlus14 && Fn->getReturnType()->isUndeducedType() && 3454 S.DeduceReturnType(Fn, R.Expression->getExprLoc(), /*Diagnose*/ false)) 3455 return {}; 3456 3457 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) 3458 if (Method->isInstance()) { 3459 // An instance method that's referenced in a form that doesn't 3460 // look like a member pointer is just invalid. 3461 if (!R.HasFormOfMemberPointer) 3462 return {}; 3463 3464 return S.Context.getMemberPointerType(Fn->getType(), 3465 S.Context.getTypeDeclType(Method->getParent()).getTypePtr()); 3466 } 3467 3468 if (!R.IsAddressOfOperand) return Fn->getType(); 3469 return S.Context.getPointerType(Fn->getType()); 3470} 3471 3472/// Apply the deduction rules for overload sets. 3473/// 3474/// \return the null type if this argument should be treated as an 3475/// undeduced context 3476static QualType 3477ResolveOverloadForDeduction(Sema &S, TemplateParameterList *TemplateParams, 3478 Expr *Arg, QualType ParamType, 3479 bool ParamWasReference) { 3480 3481 OverloadExpr::FindResult R = OverloadExpr::find(Arg); 3482 3483 OverloadExpr *Ovl = R.Expression; 3484 3485 // C++0x [temp.deduct.call]p4 3486 unsigned TDF = 0; 3487 if (ParamWasReference) 3488 TDF |= TDF_ParamWithReferenceType; 3489 if (R.IsAddressOfOperand) 3490 TDF |= TDF_IgnoreQualifiers; 3491 3492 // C++0x [temp.deduct.call]p6: 3493 // When P is a function type, pointer to function type, or pointer 3494 // to member function type: 3495 3496 if (!ParamType->isFunctionType() && 3497 !ParamType->isFunctionPointerType() && 3498 !ParamType->isMemberFunctionPointerType()) { 3499 if (Ovl->hasExplicitTemplateArgs()) { 3500 // But we can still look for an explicit specialization. 3501 if (FunctionDecl *ExplicitSpec 3502 = S.ResolveSingleFunctionTemplateSpecialization(Ovl)) 3503 return GetTypeOfFunction(S, R, ExplicitSpec); 3504 } 3505 3506 DeclAccessPair DAP; 3507 if (FunctionDecl *Viable = 3508 S.resolveAddressOfOnlyViableOverloadCandidate(Arg, DAP)) 3509 return GetTypeOfFunction(S, R, Viable); 3510 3511 return {}; 3512 } 3513 3514 // Gather the explicit template arguments, if any. 3515 TemplateArgumentListInfo ExplicitTemplateArgs; 3516 if (Ovl->hasExplicitTemplateArgs()) 3517 Ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs); 3518 QualType Match; 3519 for (UnresolvedSetIterator I = Ovl->decls_begin(), 3520 E = Ovl->decls_end(); I != E; ++I) { 3521 NamedDecl *D = (*I)->getUnderlyingDecl(); 3522 3523 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D)) { 3524 // - If the argument is an overload set containing one or more 3525 // function templates, the parameter is treated as a 3526 // non-deduced context. 3527 if (!Ovl->hasExplicitTemplateArgs()) 3528 return {}; 3529 3530 // Otherwise, see if we can resolve a function type 3531 FunctionDecl *Specialization = nullptr; 3532 TemplateDeductionInfo Info(Ovl->getNameLoc()); 3533 if (S.DeduceTemplateArguments(FunTmpl, &ExplicitTemplateArgs, 3534 Specialization, Info)) 3535 continue; 3536 3537 D = Specialization; 3538 } 3539 3540 FunctionDecl *Fn = cast<FunctionDecl>(D); 3541 QualType ArgType = GetTypeOfFunction(S, R, Fn); 3542 if (ArgType.isNull()) continue; 3543 3544 // Function-to-pointer conversion. 3545 if (!ParamWasReference && ParamType->isPointerType() && 3546 ArgType->isFunctionType()) 3547 ArgType = S.Context.getPointerType(ArgType); 3548 3549 // - If the argument is an overload set (not containing function 3550 // templates), trial argument deduction is attempted using each 3551 // of the members of the set. If deduction succeeds for only one 3552 // of the overload set members, that member is used as the 3553 // argument value for the deduction. If deduction succeeds for 3554 // more than one member of the overload set the parameter is 3555 // treated as a non-deduced context. 3556 3557 // We do all of this in a fresh context per C++0x [temp.deduct.type]p2: 3558 // Type deduction is done independently for each P/A pair, and 3559 // the deduced template argument values are then combined. 3560 // So we do not reject deductions which were made elsewhere. 3561 SmallVector<DeducedTemplateArgument, 8> 3562 Deduced(TemplateParams->size()); 3563 TemplateDeductionInfo Info(Ovl->getNameLoc()); 3564 Sema::TemplateDeductionResult Result 3565 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, ParamType, 3566 ArgType, Info, Deduced, TDF); 3567 if (Result) continue; 3568 if (!Match.isNull()) 3569 return {}; 3570 Match = ArgType; 3571 } 3572 3573 return Match; 3574} 3575 3576/// Perform the adjustments to the parameter and argument types 3577/// described in C++ [temp.deduct.call]. 3578/// 3579/// \returns true if the caller should not attempt to perform any template 3580/// argument deduction based on this P/A pair because the argument is an 3581/// overloaded function set that could not be resolved. 3582static bool AdjustFunctionParmAndArgTypesForDeduction( 3583 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex, 3584 QualType &ParamType, QualType &ArgType, Expr *Arg, unsigned &TDF) { 3585 // C++0x [temp.deduct.call]p3: 3586 // If P is a cv-qualified type, the top level cv-qualifiers of P's type 3587 // are ignored for type deduction. 3588 if (ParamType.hasQualifiers())

←

Assuming the condition is false

→

←

Taking false branch

→

3589 ParamType = ParamType.getUnqualifiedType(); 3590 3591 // [...] If P is a reference type, the type referred to by P is 3592 // used for type deduction. 3593 const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>();

←

Assuming the object is not a 'ReferenceType'

→

3594 if (ParamRefType

20.1	'ParamRefType' is null

20.1	'ParamRefType' is null

20.1	'ParamRefType' is null

)

←

Taking false branch

→

3595 ParamType = ParamRefType->getPointeeType(); 3596 3597 // Overload sets usually make this parameter an undeduced context, 3598 // but there are sometimes special circumstances. Typically 3599 // involving a template-id-expr. 3600 if (ArgType == S.Context.OverloadTy) {

←

Calling 'operator=='

→

←

Returning from 'operator=='

→

←

Taking false branch

→

3601 ArgType = ResolveOverloadForDeduction(S, TemplateParams, 3602 Arg, ParamType, 3603 ParamRefType != nullptr); 3604 if (ArgType.isNull()) 3605 return true; 3606 } 3607 3608 if (ParamRefType

29.1	'ParamRefType' is null

29.1	'ParamRefType' is null

29.1	'ParamRefType' is null

) {

←

Taking false branch

→

3609 // If the argument has incomplete array type, try to complete its type. 3610 if (ArgType->isIncompleteArrayType()) { 3611 S.completeExprArrayBound(Arg); 3612 ArgType = Arg->getType(); 3613 } 3614 3615 // C++1z [temp.deduct.call]p3: 3616 // If P is a forwarding reference and the argument is an lvalue, the type 3617 // "lvalue reference to A" is used in place of A for type deduction. 3618 if (isForwardingReference(QualType(ParamRefType, 0), FirstInnerIndex) && 3619 Arg->isLValue()) 3620 ArgType = S.Context.getLValueReferenceType(ArgType); 3621 } else { 3622 // C++ [temp.deduct.call]p2: 3623 // If P is not a reference type: 3624 // - If A is an array type, the pointer type produced by the 3625 // array-to-pointer standard conversion (4.2) is used in place of 3626 // A for type deduction; otherwise, 3627 if (ArgType->isArrayType())

←

Taking false branch

→

3628 ArgType = S.Context.getArrayDecayedType(ArgType); 3629 // - If A is a function type, the pointer type produced by the 3630 // function-to-pointer standard conversion (4.3) is used in place 3631 // of A for type deduction; otherwise, 3632 else if (ArgType->isFunctionType())

←

Taking true branch

→

3633 ArgType = S.Context.getPointerType(ArgType); 3634 else { 3635 // - If A is a cv-qualified type, the top level cv-qualifiers of A's 3636 // type are ignored for type deduction. 3637 ArgType = ArgType.getUnqualifiedType(); 3638 } 3639 } 3640 3641 // C++0x [temp.deduct.call]p4: 3642 // In general, the deduction process attempts to find template argument 3643 // values that will make the deduced A identical to A (after the type A 3644 // is transformed as described above). [...] 3645 TDF = TDF_SkipNonDependent; 3646 3647 // - If the original P is a reference type, the deduced A (i.e., the 3648 // type referred to by the reference) can be more cv-qualified than 3649 // the transformed A. 3650 if (ParamRefType

32.1	'ParamRefType' is null

32.1	'ParamRefType' is null

32.1	'ParamRefType' is null

)

←

Taking false branch

→

3651 TDF |= TDF_ParamWithReferenceType; 3652 // - The transformed A can be another pointer or pointer to member 3653 // type that can be converted to the deduced A via a qualification 3654 // conversion (4.4). 3655 if (ArgType->isPointerType() || ArgType->isMemberPointerType() ||

←

Taking false branch

→

3656 ArgType->isObjCObjectPointerType()) 3657 TDF |= TDF_IgnoreQualifiers; 3658 // - If P is a class and P has the form simple-template-id, then the 3659 // transformed A can be a derived class of the deduced A. Likewise, 3660 // if P is a pointer to a class of the form simple-template-id, the 3661 // transformed A can be a pointer to a derived class pointed to by 3662 // the deduced A. 3663 if (isSimpleTemplateIdType(ParamType) ||

←

Calling 'isSimpleTemplateIdType'

→

←

Returning from 'isSimpleTemplateIdType'

→

3664 (isa<PointerType>(ParamType) &&

←

Assuming 'ParamType' is a 'PointerType'

→

3665 isSimpleTemplateIdType( 3666 ParamType->getAs<PointerType>()->getPointeeType())))

←

Assuming the object is not a 'PointerType'

→

←

Called C++ object pointer is null

3667 TDF |= TDF_DerivedClass; 3668 3669 return false; 3670} 3671 3672static bool 3673hasDeducibleTemplateParameters(Sema &S, FunctionTemplateDecl *FunctionTemplate, 3674 QualType T); 3675 3676static Sema::TemplateDeductionResult DeduceTemplateArgumentsFromCallArgument( 3677 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex, 3678 QualType ParamType, Expr *Arg, TemplateDeductionInfo &Info, 3679 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3680 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs, 3681 bool DecomposedParam, unsigned ArgIdx, unsigned TDF); 3682 3683/// Attempt template argument deduction from an initializer list 3684/// deemed to be an argument in a function call. 3685static Sema::TemplateDeductionResult DeduceFromInitializerList( 3686 Sema &S, TemplateParameterList *TemplateParams, QualType AdjustedParamType, 3687 InitListExpr *ILE, TemplateDeductionInfo &Info, 3688 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3689 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs, unsigned ArgIdx, 3690 unsigned TDF) { 3691 // C++ [temp.deduct.call]p1: (CWG 1591) 3692 // If removing references and cv-qualifiers from P gives 3693 // std::initializer_list<P0> or P0[N] for some P0 and N and the argument is 3694 // a non-empty initializer list, then deduction is performed instead for 3695 // each element of the initializer list, taking P0 as a function template 3696 // parameter type and the initializer element as its argument 3697 // 3698 // We've already removed references and cv-qualifiers here. 3699 if (!ILE->getNumInits()) 3700 return Sema::TDK_Success; 3701 3702 QualType ElTy; 3703 auto *ArrTy = S.Context.getAsArrayType(AdjustedParamType); 3704 if (ArrTy) 3705 ElTy = ArrTy->getElementType(); 3706 else if (!S.isStdInitializerList(AdjustedParamType, &ElTy)) { 3707 // Otherwise, an initializer list argument causes the parameter to be 3708 // considered a non-deduced context 3709 return Sema::TDK_Success; 3710 } 3711 3712 // Resolving a core issue: a braced-init-list containing any designators is 3713 // a non-deduced context. 3714 for (Expr *E : ILE->inits()) 3715 if (isa<DesignatedInitExpr>(E)) 3716 return Sema::TDK_Success; 3717 3718 // Deduction only needs to be done for dependent types. 3719 if (ElTy->isDependentType()) { 3720 for (Expr *E : ILE->inits()) { 3721 if (auto Result = DeduceTemplateArgumentsFromCallArgument( 3722 S, TemplateParams, 0, ElTy, E, Info, Deduced, OriginalCallArgs, true, 3723 ArgIdx, TDF)) 3724 return Result; 3725 } 3726 } 3727 3728 // in the P0[N] case, if N is a non-type template parameter, N is deduced 3729 // from the length of the initializer list. 3730 if (auto *DependentArrTy = dyn_cast_or_null<DependentSizedArrayType>(ArrTy)) { 3731 // Determine the array bound is something we can deduce. 3732 if (NonTypeTemplateParmDecl *NTTP = 3733 getDeducedParameterFromExpr(Info, DependentArrTy->getSizeExpr())) { 3734 // We can perform template argument deduction for the given non-type 3735 // template parameter. 3736 // C++ [temp.deduct.type]p13: 3737 // The type of N in the type T[N] is std::size_t. 3738 QualType T = S.Context.getSizeType(); 3739 llvm::APInt Size(S.Context.getIntWidth(T), ILE->getNumInits()); 3740 if (auto Result = DeduceNonTypeTemplateArgument( 3741 S, TemplateParams, NTTP, llvm::APSInt(Size), T, 3742 /*ArrayBound=*/true, Info, Deduced)) 3743 return Result; 3744 } 3745 } 3746 3747 return Sema::TDK_Success; 3748} 3749 3750/// Perform template argument deduction per [temp.deduct.call] for a 3751/// single parameter / argument pair. 3752static Sema::TemplateDeductionResult DeduceTemplateArgumentsFromCallArgument( 3753 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex, 3754 QualType ParamType, Expr *Arg, TemplateDeductionInfo &Info, 3755 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3756 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs, 3757 bool DecomposedParam, unsigned ArgIdx, unsigned TDF) { 3758 QualType ArgType = Arg->getType(); 3759 QualType OrigParamType = ParamType; 3760 3761 // If P is a reference type [...] 3762 // If P is a cv-qualified type [...] 3763 if (AdjustFunctionParmAndArgTypesForDeduction(

←

Calling 'AdjustFunctionParmAndArgTypesForDeduction'

→

3764 S, TemplateParams, FirstInnerIndex, ParamType, ArgType, Arg, TDF)) 3765 return Sema::TDK_Success; 3766 3767 // If [...] the argument is a non-empty initializer list [...] 3768 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Arg)) 3769 return DeduceFromInitializerList(S, TemplateParams, ParamType, ILE, Info, 3770 Deduced, OriginalCallArgs, ArgIdx, TDF); 3771 3772 // [...] the deduction process attempts to find template argument values 3773 // that will make the deduced A identical to A 3774 // 3775 // Keep track of the argument type and corresponding parameter index, 3776 // so we can check for compatibility between the deduced A and A. 3777 OriginalCallArgs.push_back( 3778 Sema::OriginalCallArg(OrigParamType, DecomposedParam, ArgIdx, ArgType)); 3779 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, ParamType, 3780 ArgType, Info, Deduced, TDF); 3781} 3782 3783/// Perform template argument deduction from a function call 3784/// (C++ [temp.deduct.call]). 3785/// 3786/// \param FunctionTemplate the function template for which we are performing 3787/// template argument deduction. 3788/// 3789/// \param ExplicitTemplateArgs the explicit template arguments provided 3790/// for this call. 3791/// 3792/// \param Args the function call arguments 3793/// 3794/// \param Specialization if template argument deduction was successful, 3795/// this will be set to the function template specialization produced by 3796/// template argument deduction. 3797/// 3798/// \param Info the argument will be updated to provide additional information 3799/// about template argument deduction. 3800/// 3801/// \param CheckNonDependent A callback to invoke to check conversions for 3802/// non-dependent parameters, between deduction and substitution, per DR1391. 3803/// If this returns true, substitution will be skipped and we return 3804/// TDK_NonDependentConversionFailure. The callback is passed the parameter 3805/// types (after substituting explicit template arguments). 3806/// 3807/// \returns the result of template argument deduction. 3808Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( 3809 FunctionTemplateDecl *FunctionTemplate, 3810 TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args, 3811 FunctionDecl *&Specialization, TemplateDeductionInfo &Info, 3812 bool PartialOverloading, 3813 llvm::function_ref<bool(ArrayRef<QualType>)> CheckNonDependent) { 3814 if (FunctionTemplate->isInvalidDecl())

Assuming the condition is false

→

←

Taking false branch

→

3815 return TDK_Invalid; 3816 3817 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 3818 unsigned NumParams = Function->getNumParams(); 3819 3820 unsigned FirstInnerIndex = getFirstInnerIndex(FunctionTemplate); 3821 3822 // C++ [temp.deduct.call]p1: 3823 // Template argument deduction is done by comparing each function template 3824 // parameter type (call it P) with the type of the corresponding argument 3825 // of the call (call it A) as described below. 3826 if (Args.size() < Function->getMinRequiredArguments() && !PartialOverloading)

←

Assuming the condition is false

→

3827 return TDK_TooFewArguments; 3828 else if (TooManyArguments(NumParams, Args.size(), PartialOverloading)) {

←

Taking false branch

→

3829 const auto *Proto = Function->getType()->castAs<FunctionProtoType>(); 3830 if (Proto->isTemplateVariadic()) 3831 /* Do nothing */; 3832 else if (!Proto->isVariadic()) 3833 return TDK_TooManyArguments; 3834 } 3835 3836 // The types of the parameters from which we will perform template argument 3837 // deduction. 3838 LocalInstantiationScope InstScope(*this); 3839 TemplateParameterList *TemplateParams 3840 = FunctionTemplate->getTemplateParameters(); 3841 SmallVector<DeducedTemplateArgument, 4> Deduced; 3842 SmallVector<QualType, 8> ParamTypes; 3843 unsigned NumExplicitlySpecified = 0; 3844 if (ExplicitTemplateArgs) {

←

Assuming 'ExplicitTemplateArgs' is null

→

←

Taking false branch

→

3845 TemplateDeductionResult Result = 3846 SubstituteExplicitTemplateArguments(FunctionTemplate, 3847 *ExplicitTemplateArgs, 3848 Deduced, 3849 ParamTypes, 3850 nullptr, 3851 Info); 3852 if (Result) 3853 return Result; 3854 3855 NumExplicitlySpecified = Deduced.size(); 3856 } else { 3857 // Just fill in the parameter types from the function declaration. 3858 for (unsigned I = 0; I != NumParams; ++I)

←

Assuming 'I' is equal to 'NumParams'

→

←

Loop condition is false. Execution continues on line 3862

→

3859 ParamTypes.push_back(Function->getParamDecl(I)->getType()); 3860 } 3861 3862 SmallVector<OriginalCallArg, 8> OriginalCallArgs; 3863 3864 // Deduce an argument of type ParamType from an expression with index ArgIdx. 3865 auto DeduceCallArgument = [&](QualType ParamType, unsigned ArgIdx) { 3866 // C++ [demp.deduct.call]p1: (DR1391) 3867 // Template argument deduction is done by comparing each function template 3868 // parameter that contains template-parameters that participate in 3869 // template argument deduction ... 3870 if (!hasDeducibleTemplateParameters(*this, FunctionTemplate, ParamType))

←

Taking false branch

→

3871 return Sema::TDK_Success; 3872 3873 // ... with the type of the corresponding argument 3874 return DeduceTemplateArgumentsFromCallArgument(

←

Calling 'DeduceTemplateArgumentsFromCallArgument'

→

3875 *this, TemplateParams, FirstInnerIndex, ParamType, Args[ArgIdx], Info, Deduced, 3876 OriginalCallArgs, /*Decomposed*/false, ArgIdx, /*TDF*/ 0); 3877 }; 3878 3879 // Deduce template arguments from the function parameters. 3880 Deduced.resize(TemplateParams->size()); 3881 SmallVector<QualType, 8> ParamTypesForArgChecking; 3882 for (unsigned ParamIdx = 0, NumParamTypes = ParamTypes.size(), ArgIdx = 0;

←

Loop condition is true. Entering loop body

→

3883 ParamIdx != NumParamTypes; ++ParamIdx) {

←

Assuming 'ParamIdx' is not equal to 'NumParamTypes'

→

3884 QualType ParamType = ParamTypes[ParamIdx]; 3885 3886 const PackExpansionType *ParamExpansion = 3887 dyn_cast<PackExpansionType>(ParamType); 3888 if (!ParamExpansion

10.1	'ParamExpansion' is null

10.1	'ParamExpansion' is null

10.1	'ParamExpansion' is null

) {

←

Taking true branch

→

3889 // Simple case: matching a function parameter to a function argument. 3890 if (ArgIdx >= Args.size())

←

Assuming the condition is false

→

←

Taking false branch

→

3891 break; 3892 3893 ParamTypesForArgChecking.push_back(ParamType); 3894 if (auto Result = DeduceCallArgument(ParamType, ArgIdx++))

←

Calling 'operator()'

→

3895 return Result; 3896 3897 continue; 3898 } 3899 3900 QualType ParamPattern = ParamExpansion->getPattern(); 3901 PackDeductionScope PackScope(*this, TemplateParams, Deduced, Info, 3902 ParamPattern); 3903 3904 // C++0x [temp.deduct.call]p1: 3905 // For a function parameter pack that occurs at the end of the 3906 // parameter-declaration-list, the type A of each remaining argument of 3907 // the call is compared with the type P of the declarator-id of the 3908 // function parameter pack. Each comparison deduces template arguments 3909 // for subsequent positions in the template parameter packs expanded by 3910 // the function parameter pack. When a function parameter pack appears 3911 // in a non-deduced context [not at the end of the list], the type of 3912 // that parameter pack is never deduced. 3913 // 3914 // FIXME: The above rule allows the size of the parameter pack to change 3915 // after we skip it (in the non-deduced case). That makes no sense, so 3916 // we instead notionally deduce the pack against N arguments, where N is 3917 // the length of the explicitly-specified pack if it's expanded by the 3918 // parameter pack and 0 otherwise, and we treat each deduction as a 3919 // non-deduced context. 3920 if (ParamIdx + 1 == NumParamTypes || PackScope.hasFixedArity()) { 3921 for (; ArgIdx < Args.size() && PackScope.hasNextElement(); 3922 PackScope.nextPackElement(), ++ArgIdx) { 3923 ParamTypesForArgChecking.push_back(ParamPattern); 3924 if (auto Result = DeduceCallArgument(ParamPattern, ArgIdx)) 3925 return Result; 3926 } 3927 } else { 3928 // If the parameter type contains an explicitly-specified pack that we 3929 // could not expand, skip the number of parameters notionally created 3930 // by the expansion. 3931 Optional<unsigned> NumExpansions = ParamExpansion->getNumExpansions(); 3932 if (NumExpansions && !PackScope.isPartiallyExpanded()) { 3933 for (unsigned I = 0; I != *NumExpansions && ArgIdx < Args.size(); 3934 ++I, ++ArgIdx) { 3935 ParamTypesForArgChecking.push_back(ParamPattern); 3936 // FIXME: Should we add OriginalCallArgs for these? What if the 3937 // corresponding argument is a list? 3938 PackScope.nextPackElement(); 3939 } 3940 } 3941 } 3942 3943 // Build argument packs for each of the parameter packs expanded by this 3944 // pack expansion. 3945 if (auto Result = PackScope.finish()) 3946 return Result; 3947 } 3948 3949 // Capture the context in which the function call is made. This is the context 3950 // that is needed when the accessibility of template arguments is checked. 3951 DeclContext *CallingCtx = CurContext; 3952 3953 return FinishTemplateArgumentDeduction( 3954 FunctionTemplate, Deduced, NumExplicitlySpecified, Specialization, Info, 3955 &OriginalCallArgs, PartialOverloading, [&, CallingCtx]() { 3956 ContextRAII SavedContext(*this, CallingCtx); 3957 return CheckNonDependent(ParamTypesForArgChecking); 3958 }); 3959} 3960 3961QualType Sema::adjustCCAndNoReturn(QualType ArgFunctionType, 3962 QualType FunctionType, 3963 bool AdjustExceptionSpec) { 3964 if (ArgFunctionType.isNull()) 3965 return ArgFunctionType; 3966 3967 const auto *FunctionTypeP = FunctionType->castAs<FunctionProtoType>(); 3968 const auto *ArgFunctionTypeP = ArgFunctionType->castAs<FunctionProtoType>(); 3969 FunctionProtoType::ExtProtoInfo EPI = ArgFunctionTypeP->getExtProtoInfo(); 3970 bool Rebuild = false; 3971 3972 CallingConv CC = FunctionTypeP->getCallConv(); 3973 if (EPI.ExtInfo.getCC() != CC) { 3974 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC); 3975 Rebuild = true; 3976 } 3977 3978 bool NoReturn = FunctionTypeP->getNoReturnAttr(); 3979 if (EPI.ExtInfo.getNoReturn() != NoReturn) { 3980 EPI.ExtInfo = EPI.ExtInfo.withNoReturn(NoReturn); 3981 Rebuild = true; 3982 } 3983 3984 if (AdjustExceptionSpec && (FunctionTypeP->hasExceptionSpec() || 3985 ArgFunctionTypeP->hasExceptionSpec())) { 3986 EPI.ExceptionSpec = FunctionTypeP->getExtProtoInfo().ExceptionSpec; 3987 Rebuild = true; 3988 } 3989 3990 if (!Rebuild) 3991 return ArgFunctionType; 3992 3993 return Context.getFunctionType(ArgFunctionTypeP->getReturnType(), 3994 ArgFunctionTypeP->getParamTypes(), EPI); 3995} 3996 3997/// Deduce template arguments when taking the address of a function 3998/// template (C++ [temp.deduct.funcaddr]) or matching a specialization to 3999/// a template. 4000/// 4001/// \param FunctionTemplate the function template for which we are performing 4002/// template argument deduction. 4003/// 4004/// \param ExplicitTemplateArgs the explicitly-specified template 4005/// arguments. 4006/// 4007/// \param ArgFunctionType the function type that will be used as the 4008/// "argument" type (A) when performing template argument deduction from the 4009/// function template's function type. This type may be NULL, if there is no 4010/// argument type to compare against, in C++0x [temp.arg.explicit]p3. 4011/// 4012/// \param Specialization if template argument deduction was successful, 4013/// this will be set to the function template specialization produced by 4014/// template argument deduction. 4015/// 4016/// \param Info the argument will be updated to provide additional information 4017/// about template argument deduction. 4018/// 4019/// \param IsAddressOfFunction If \c true, we are deducing as part of taking 4020/// the address of a function template per [temp.deduct.funcaddr] and 4021/// [over.over]. If \c false, we are looking up a function template 4022/// specialization based on its signature, per [temp.deduct.decl]. 4023/// 4024/// \returns the result of template argument deduction. 4025Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( 4026 FunctionTemplateDecl *FunctionTemplate, 4027 TemplateArgumentListInfo *ExplicitTemplateArgs, QualType ArgFunctionType, 4028 FunctionDecl *&Specialization, TemplateDeductionInfo &Info, 4029 bool IsAddressOfFunction) { 4030 if (FunctionTemplate->isInvalidDecl()) 4031 return TDK_Invalid; 4032 4033 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 4034 TemplateParameterList *TemplateParams 4035 = FunctionTemplate->getTemplateParameters(); 4036 QualType FunctionType = Function->getType(); 4037 4038 // Substitute any explicit template arguments. 4039 LocalInstantiationScope InstScope(*this); 4040 SmallVector<DeducedTemplateArgument, 4> Deduced; 4041 unsigned NumExplicitlySpecified = 0; 4042 SmallVector<QualType, 4> ParamTypes; 4043 if (ExplicitTemplateArgs) { 4044 if (TemplateDeductionResult Result 4045 = SubstituteExplicitTemplateArguments(FunctionTemplate, 4046 *ExplicitTemplateArgs, 4047 Deduced, ParamTypes, 4048 &FunctionType, Info)) 4049 return Result; 4050 4051 NumExplicitlySpecified = Deduced.size(); 4052 } 4053 4054 // When taking the address of a function, we require convertibility of 4055 // the resulting function type. Otherwise, we allow arbitrary mismatches 4056 // of calling convention and noreturn. 4057 if (!IsAddressOfFunction) 4058 ArgFunctionType = adjustCCAndNoReturn(ArgFunctionType, FunctionType, 4059 /*AdjustExceptionSpec*/false); 4060 4061 // Unevaluated SFINAE context. 4062 EnterExpressionEvaluationContext Unevaluated( 4063 *this, Sema::ExpressionEvaluationContext::Unevaluated); 4064 SFINAETrap Trap(*this); 4065 4066 Deduced.resize(TemplateParams->size()); 4067 4068 // If the function has a deduced return type, substitute it for a dependent 4069 // type so that we treat it as a non-deduced context in what follows. If we 4070 // are looking up by signature, the signature type should also have a deduced 4071 // return type, which we instead expect to exactly match. 4072 bool HasDeducedReturnType = false; 4073 if (getLangOpts().CPlusPlus14 && IsAddressOfFunction && 4074 Function->getReturnType()->getContainedAutoType()) { 4075 FunctionType = SubstAutoType(FunctionType, Context.DependentTy); 4076 HasDeducedReturnType = true; 4077 } 4078 4079 if (!ArgFunctionType.isNull()) { 4080 unsigned TDF = 4081 TDF_TopLevelParameterTypeList | TDF_AllowCompatibleFunctionType; 4082 // Deduce template arguments from the function type. 4083 if (TemplateDeductionResult Result 4084 = DeduceTemplateArgumentsByTypeMatch(*this, TemplateParams, 4085 FunctionType, ArgFunctionType, 4086 Info, Deduced, TDF)) 4087 return Result; 4088 } 4089 4090 if (TemplateDeductionResult Result 4091 = FinishTemplateArgumentDeduction(FunctionTemplate, Deduced, 4092 NumExplicitlySpecified, 4093 Specialization, Info)) 4094 return Result; 4095 4096 // If the function has a deduced return type, deduce it now, so we can check 4097 // that the deduced function type matches the requested type. 4098 if (HasDeducedReturnType && 4099 Specialization->getReturnType()->isUndeducedType() && 4100 DeduceReturnType(Specialization, Info.getLocation(), false)) 4101 return TDK_MiscellaneousDeductionFailure; 4102 4103 // If the function has a dependent exception specification, resolve it now, 4104 // so we can check that the exception specification matches. 4105 auto *SpecializationFPT = 4106 Specialization->getType()->castAs<FunctionProtoType>(); 4107 if (getLangOpts().CPlusPlus17 && 4108 isUnresolvedExceptionSpec(SpecializationFPT->getExceptionSpecType()) && 4109 !ResolveExceptionSpec(Info.getLocation(), SpecializationFPT)) 4110 return TDK_MiscellaneousDeductionFailure; 4111 4112 // Adjust the exception specification of the argument to match the 4113 // substituted and resolved type we just formed. (Calling convention and 4114 // noreturn can't be dependent, so we don't actually need this for them 4115 // right now.) 4116 QualType SpecializationType = Specialization->getType(); 4117 if (!IsAddressOfFunction) 4118 ArgFunctionType = adjustCCAndNoReturn(ArgFunctionType, SpecializationType, 4119 /*AdjustExceptionSpec*/true); 4120 4121 // If the requested function type does not match the actual type of the 4122 // specialization with respect to arguments of compatible pointer to function 4123 // types, template argument deduction fails. 4124 if (!ArgFunctionType.isNull()) { 4125 if (IsAddressOfFunction && 4126 !isSameOrCompatibleFunctionType( 4127 Context.getCanonicalType(SpecializationType), 4128 Context.getCanonicalType(ArgFunctionType))) 4129 return TDK_MiscellaneousDeductionFailure; 4130 4131 if (!IsAddressOfFunction && 4132 !Context.hasSameType(SpecializationType, ArgFunctionType)) 4133 return TDK_MiscellaneousDeductionFailure; 4134 } 4135 4136 return TDK_Success; 4137} 4138 4139/// Deduce template arguments for a templated conversion 4140/// function (C++ [temp.deduct.conv]) and, if successful, produce a 4141/// conversion function template specialization. 4142Sema::TemplateDeductionResult 4143Sema::DeduceTemplateArguments(FunctionTemplateDecl *ConversionTemplate, 4144 QualType ToType, 4145 CXXConversionDecl *&Specialization, 4146 TemplateDeductionInfo &Info) { 4147 if (ConversionTemplate->isInvalidDecl()) 4148 return TDK_Invalid; 4149 4150 CXXConversionDecl *ConversionGeneric 4151 = cast<CXXConversionDecl>(ConversionTemplate->getTemplatedDecl()); 4152 4153 QualType FromType = ConversionGeneric->getConversionType(); 4154 4155 // Canonicalize the types for deduction. 4156 QualType P = Context.getCanonicalType(FromType); 4157 QualType A = Context.getCanonicalType(ToType); 4158 4159 // C++0x [temp.deduct.conv]p2: 4160 // If P is a reference type, the type referred to by P is used for 4161 // type deduction. 4162 if (const ReferenceType *PRef = P->getAs<ReferenceType>()) 4163 P = PRef->getPointeeType(); 4164 4165 // C++0x [temp.deduct.conv]p4: 4166 // [...] If A is a reference type, the type referred to by A is used 4167 // for type deduction. 4168 if (const ReferenceType *ARef = A->getAs<ReferenceType>()) { 4169 A = ARef->getPointeeType(); 4170 // We work around a defect in the standard here: cv-qualifiers are also 4171 // removed from P and A in this case, unless P was a reference type. This 4172 // seems to mostly match what other compilers are doing. 4173 if (!FromType->getAs<ReferenceType>()) { 4174 A = A.getUnqualifiedType(); 4175 P = P.getUnqualifiedType(); 4176 } 4177 4178 // C++ [temp.deduct.conv]p3: 4179 // 4180 // If A is not a reference type: 4181 } else { 4182 assert(!A->isReferenceType() && "Reference types were handled above")((!A->isReferenceType() && "Reference types were handled above"
) ? static_cast<void> (0) : __assert_fail ("!A->isReferenceType() && \"Reference types were handled above\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4182, __PRETTY_FUNCTION__)); 4183 4184 // - If P is an array type, the pointer type produced by the 4185 // array-to-pointer standard conversion (4.2) is used in place 4186 // of P for type deduction; otherwise, 4187 if (P->isArrayType()) 4188 P = Context.getArrayDecayedType(P); 4189 // - If P is a function type, the pointer type produced by the 4190 // function-to-pointer standard conversion (4.3) is used in 4191 // place of P for type deduction; otherwise, 4192 else if (P->isFunctionType()) 4193 P = Context.getPointerType(P); 4194 // - If P is a cv-qualified type, the top level cv-qualifiers of 4195 // P's type are ignored for type deduction. 4196 else 4197 P = P.getUnqualifiedType(); 4198 4199 // C++0x [temp.deduct.conv]p4: 4200 // If A is a cv-qualified type, the top level cv-qualifiers of A's 4201 // type are ignored for type deduction. If A is a reference type, the type 4202 // referred to by A is used for type deduction. 4203 A = A.getUnqualifiedType(); 4204 } 4205 4206 // Unevaluated SFINAE context. 4207 EnterExpressionEvaluationContext Unevaluated( 4208 *this, Sema::ExpressionEvaluationContext::Unevaluated); 4209 SFINAETrap Trap(*this); 4210 4211 // C++ [temp.deduct.conv]p1: 4212 // Template argument deduction is done by comparing the return 4213 // type of the template conversion function (call it P) with the 4214 // type that is required as the result of the conversion (call it 4215 // A) as described in 14.8.2.4. 4216 TemplateParameterList *TemplateParams 4217 = ConversionTemplate->getTemplateParameters(); 4218 SmallVector<DeducedTemplateArgument, 4> Deduced; 4219 Deduced.resize(TemplateParams->size()); 4220 4221 // C++0x [temp.deduct.conv]p4: 4222 // In general, the deduction process attempts to find template 4223 // argument values that will make the deduced A identical to 4224 // A. However, there are two cases that allow a difference: 4225 unsigned TDF = 0; 4226 // - If the original A is a reference type, A can be more 4227 // cv-qualified than the deduced A (i.e., the type referred to 4228 // by the reference) 4229 if (ToType->isReferenceType()) 4230 TDF |= TDF_ArgWithReferenceType; 4231 // - The deduced A can be another pointer or pointer to member 4232 // type that can be converted to A via a qualification 4233 // conversion. 4234 // 4235 // (C++0x [temp.deduct.conv]p6 clarifies that this only happens when 4236 // both P and A are pointers or member pointers. In this case, we 4237 // just ignore cv-qualifiers completely). 4238 if ((P->isPointerType() && A->isPointerType()) || 4239 (P->isMemberPointerType() && A->isMemberPointerType())) 4240 TDF |= TDF_IgnoreQualifiers; 4241 if (TemplateDeductionResult Result 4242 = DeduceTemplateArgumentsByTypeMatch(*this, TemplateParams, 4243 P, A, Info, Deduced, TDF)) 4244 return Result; 4245 4246 // Create an Instantiation Scope for finalizing the operator. 4247 LocalInstantiationScope InstScope(*this); 4248 // Finish template argument deduction. 4249 FunctionDecl *ConversionSpecialized = nullptr; 4250 TemplateDeductionResult Result 4251 = FinishTemplateArgumentDeduction(ConversionTemplate, Deduced, 0, 4252 ConversionSpecialized, Info); 4253 Specialization = cast_or_null<CXXConversionDecl>(ConversionSpecialized); 4254 return Result; 4255} 4256 4257/// Deduce template arguments for a function template when there is 4258/// nothing to deduce against (C++0x [temp.arg.explicit]p3). 4259/// 4260/// \param FunctionTemplate the function template for which we are performing 4261/// template argument deduction. 4262/// 4263/// \param ExplicitTemplateArgs the explicitly-specified template 4264/// arguments. 4265/// 4266/// \param Specialization if template argument deduction was successful, 4267/// this will be set to the function template specialization produced by 4268/// template argument deduction. 4269/// 4270/// \param Info the argument will be updated to provide additional information 4271/// about template argument deduction. 4272/// 4273/// \param IsAddressOfFunction If \c true, we are deducing as part of taking 4274/// the address of a function template in a context where we do not have a 4275/// target type, per [over.over]. If \c false, we are looking up a function 4276/// template specialization based on its signature, which only happens when 4277/// deducing a function parameter type from an argument that is a template-id 4278/// naming a function template specialization. 4279/// 4280/// \returns the result of template argument deduction. 4281Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( 4282 FunctionTemplateDecl *FunctionTemplate, 4283 TemplateArgumentListInfo *ExplicitTemplateArgs, 4284 FunctionDecl *&Specialization, TemplateDeductionInfo &Info, 4285 bool IsAddressOfFunction) { 4286 return DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 4287 QualType(), Specialization, Info, 4288 IsAddressOfFunction); 4289} 4290 4291namespace { 4292 struct DependentAuto { bool IsPack; }; 4293 4294 /// Substitute the 'auto' specifier or deduced template specialization type 4295 /// specifier within a type for a given replacement type. 4296 class SubstituteDeducedTypeTransform : 4297 public TreeTransform<SubstituteDeducedTypeTransform> { 4298 QualType Replacement; 4299 bool ReplacementIsPack; 4300 bool UseTypeSugar; 4301 4302 public: 4303 SubstituteDeducedTypeTransform(Sema &SemaRef, DependentAuto DA) 4304 : TreeTransform<SubstituteDeducedTypeTransform>(SemaRef), Replacement(), 4305 ReplacementIsPack(DA.IsPack), UseTypeSugar(true) {} 4306 4307 SubstituteDeducedTypeTransform(Sema &SemaRef, QualType Replacement, 4308 bool UseTypeSugar = true) 4309 : TreeTransform<SubstituteDeducedTypeTransform>(SemaRef), 4310 Replacement(Replacement), ReplacementIsPack(false), 4311 UseTypeSugar(UseTypeSugar) {} 4312 4313 QualType TransformDesugared(TypeLocBuilder &TLB, DeducedTypeLoc TL) { 4314 assert(isa<TemplateTypeParmType>(Replacement) &&((isa<TemplateTypeParmType>(Replacement) && "unexpected unsugared replacement kind"
) ? static_cast<void> (0) : __assert_fail ("isa<TemplateTypeParmType>(Replacement) && \"unexpected unsugared replacement kind\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4315, __PRETTY_FUNCTION__)) 4315 "unexpected unsugared replacement kind")((isa<TemplateTypeParmType>(Replacement) && "unexpected unsugared replacement kind"
) ? static_cast<void> (0) : __assert_fail ("isa<TemplateTypeParmType>(Replacement) && \"unexpected unsugared replacement kind\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4315, __PRETTY_FUNCTION__)); 4316 QualType Result = Replacement; 4317 TemplateTypeParmTypeLoc NewTL = TLB.push<TemplateTypeParmTypeLoc>(Result); 4318 NewTL.setNameLoc(TL.getNameLoc()); 4319 return Result; 4320 } 4321 4322 QualType TransformAutoType(TypeLocBuilder &TLB, AutoTypeLoc TL) { 4323 // If we're building the type pattern to deduce against, don't wrap the 4324 // substituted type in an AutoType. Certain template deduction rules 4325 // apply only when a template type parameter appears directly (and not if 4326 // the parameter is found through desugaring). For instance: 4327 // auto &&lref = lvalue; 4328 // must transform into "rvalue reference to T" not "rvalue reference to 4329 // auto type deduced as T" in order for [temp.deduct.call]p3 to apply. 4330 // 4331 // FIXME: Is this still necessary? 4332 if (!UseTypeSugar) 4333 return TransformDesugared(TLB, TL); 4334 4335 QualType Result = SemaRef.Context.getAutoType( 4336 Replacement, TL.getTypePtr()->getKeyword(), Replacement.isNull(), 4337 ReplacementIsPack); 4338 auto NewTL = TLB.push<AutoTypeLoc>(Result); 4339 NewTL.setNameLoc(TL.getNameLoc()); 4340 return Result; 4341 } 4342 4343 QualType TransformDeducedTemplateSpecializationType( 4344 TypeLocBuilder &TLB, DeducedTemplateSpecializationTypeLoc TL) { 4345 if (!UseTypeSugar) 4346 return TransformDesugared(TLB, TL); 4347 4348 QualType Result = SemaRef.Context.getDeducedTemplateSpecializationType( 4349 TL.getTypePtr()->getTemplateName(), 4350 Replacement, Replacement.isNull()); 4351 auto NewTL = TLB.push<DeducedTemplateSpecializationTypeLoc>(Result); 4352 NewTL.setNameLoc(TL.getNameLoc()); 4353 return Result; 4354 } 4355 4356 ExprResult TransformLambdaExpr(LambdaExpr *E) { 4357 // Lambdas never need to be transformed. 4358 return E; 4359 } 4360 4361 QualType Apply(TypeLoc TL) { 4362 // Create some scratch storage for the transformed type locations. 4363 // FIXME: We're just going to throw this information away. Don't build it. 4364 TypeLocBuilder TLB; 4365 TLB.reserve(TL.getFullDataSize()); 4366 return TransformType(TLB, TL); 4367 } 4368 }; 4369 4370} // namespace 4371 4372Sema::DeduceAutoResult 4373Sema::DeduceAutoType(TypeSourceInfo *Type, Expr *&Init, QualType &Result, 4374 Optional<unsigned> DependentDeductionDepth) { 4375 return DeduceAutoType(Type->getTypeLoc(), Init, Result, 4376 DependentDeductionDepth); 4377} 4378 4379/// Attempt to produce an informative diagostic explaining why auto deduction 4380/// failed. 4381/// \return \c true if diagnosed, \c false if not. 4382static bool diagnoseAutoDeductionFailure(Sema &S, 4383 Sema::TemplateDeductionResult TDK, 4384 TemplateDeductionInfo &Info, 4385 ArrayRef<SourceRange> Ranges) { 4386 switch (TDK) { 4387 case Sema::TDK_Inconsistent: { 4388 // Inconsistent deduction means we were deducing from an initializer list. 4389 auto D = S.Diag(Info.getLocation(), diag::err_auto_inconsistent_deduction); 4390 D << Info.FirstArg << Info.SecondArg; 4391 for (auto R : Ranges) 4392 D << R; 4393 return true; 4394 } 4395 4396 // FIXME: Are there other cases for which a custom diagnostic is more useful 4397 // than the basic "types don't match" diagnostic? 4398 4399 default: 4400 return false; 4401 } 4402} 4403 4404/// Deduce the type for an auto type-specifier (C++11 [dcl.spec.auto]p6) 4405/// 4406/// Note that this is done even if the initializer is dependent. (This is 4407/// necessary to support partial ordering of templates using 'auto'.) 4408/// A dependent type will be produced when deducing from a dependent type. 4409/// 4410/// \param Type the type pattern using the auto type-specifier. 4411/// \param Init the initializer for the variable whose type is to be deduced. 4412/// \param Result if type deduction was successful, this will be set to the 4413/// deduced type. 4414/// \param DependentDeductionDepth Set if we should permit deduction in 4415/// dependent cases. This is necessary for template partial ordering with 4416/// 'auto' template parameters. The value specified is the template 4417/// parameter depth at which we should perform 'auto' deduction. 4418Sema::DeduceAutoResult 4419Sema::DeduceAutoType(TypeLoc Type, Expr *&Init, QualType &Result, 4420 Optional<unsigned> DependentDeductionDepth) { 4421 if (Init->getType()->isNonOverloadPlaceholderType()) { 4422 ExprResult NonPlaceholder = CheckPlaceholderExpr(Init); 4423 if (NonPlaceholder.isInvalid()) 4424 return DAR_FailedAlreadyDiagnosed; 4425 Init = NonPlaceholder.get(); 4426 } 4427 4428 DependentAuto DependentResult = { 4429 /*.IsPack = */ (bool)Type.getAs<PackExpansionTypeLoc>()}; 4430 4431 if (!DependentDeductionDepth && 4432 (Type.getType()->isDependentType() || Init->isTypeDependent())) { 4433 Result = SubstituteDeducedTypeTransform(*this, DependentResult).Apply(Type); 4434 assert(!Result.isNull() && "substituting DependentTy can't fail")((!Result.isNull() && "substituting DependentTy can't fail"
) ? static_cast<void> (0) : __assert_fail ("!Result.isNull() && \"substituting DependentTy can't fail\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4434, __PRETTY_FUNCTION__)); 4435 return DAR_Succeeded; 4436 } 4437 4438 // Find the depth of template parameter to synthesize. 4439 unsigned Depth = DependentDeductionDepth.getValueOr(0); 4440 4441 // If this is a 'decltype(auto)' specifier, do the decltype dance. 4442 // Since 'decltype(auto)' can only occur at the top of the type, we 4443 // don't need to go digging for it. 4444 if (const AutoType *AT = Type.getType()->getAs<AutoType>()) { 4445 if (AT->isDecltypeAuto()) { 4446 if (isa<InitListExpr>(Init)) { 4447 Diag(Init->getBeginLoc(), diag::err_decltype_auto_initializer_list); 4448 return DAR_FailedAlreadyDiagnosed; 4449 } 4450 4451 ExprResult ER = CheckPlaceholderExpr(Init); 4452 if (ER.isInvalid()) 4453 return DAR_FailedAlreadyDiagnosed; 4454 Init = ER.get(); 4455 QualType Deduced = BuildDecltypeType(Init, Init->getBeginLoc(), false); 4456 if (Deduced.isNull()) 4457 return DAR_FailedAlreadyDiagnosed; 4458 // FIXME: Support a non-canonical deduced type for 'auto'. 4459 Deduced = Context.getCanonicalType(Deduced); 4460 Result = SubstituteDeducedTypeTransform(*this, Deduced).Apply(Type); 4461 if (Result.isNull()) 4462 return DAR_FailedAlreadyDiagnosed; 4463 return DAR_Succeeded; 4464 } else if (!getLangOpts().CPlusPlus) { 4465 if (isa<InitListExpr>(Init)) { 4466 Diag(Init->getBeginLoc(), diag::err_auto_init_list_from_c); 4467 return DAR_FailedAlreadyDiagnosed; 4468 } 4469 } 4470 } 4471 4472 SourceLocation Loc = Init->getExprLoc(); 4473 4474 LocalInstantiationScope InstScope(*this); 4475 4476 // Build template<class TemplParam> void Func(FuncParam); 4477 TemplateTypeParmDecl *TemplParam = TemplateTypeParmDecl::Create( 4478 Context, nullptr, SourceLocation(), Loc, Depth, 0, nullptr, false, false); 4479 QualType TemplArg = QualType(TemplParam->getTypeForDecl(), 0); 4480 NamedDecl *TemplParamPtr = TemplParam; 4481 FixedSizeTemplateParameterListStorage<1, false> TemplateParamsSt( 4482 Loc, Loc, TemplParamPtr, Loc, nullptr); 4483 4484 QualType FuncParam = 4485 SubstituteDeducedTypeTransform(*this, TemplArg, /*UseTypeSugar*/false) 4486 .Apply(Type); 4487 assert(!FuncParam.isNull() &&((!FuncParam.isNull() && "substituting template parameter for 'auto' failed"
) ? static_cast<void> (0) : __assert_fail ("!FuncParam.isNull() && \"substituting template parameter for 'auto' failed\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4488, __PRETTY_FUNCTION__)) 4488 "substituting template parameter for 'auto' failed")((!FuncParam.isNull() && "substituting template parameter for 'auto' failed"
) ? static_cast<void> (0) : __assert_fail ("!FuncParam.isNull() && \"substituting template parameter for 'auto' failed\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4488, __PRETTY_FUNCTION__)); 4489 4490 // Deduce type of TemplParam in Func(Init) 4491 SmallVector<DeducedTemplateArgument, 1> Deduced; 4492 Deduced.resize(1); 4493 4494 TemplateDeductionInfo Info(Loc, Depth); 4495 4496 // If deduction failed, don't diagnose if the initializer is dependent; it 4497 // might acquire a matching type in the instantiation. 4498 auto DeductionFailed = [&](TemplateDeductionResult TDK, 4499 ArrayRef<SourceRange> Ranges) -> DeduceAutoResult { 4500 if (Init->isTypeDependent()) { 4501 Result = 4502 SubstituteDeducedTypeTransform(*this, DependentResult).Apply(Type); 4503 assert(!Result.isNull() && "substituting DependentTy can't fail")((!Result.isNull() && "substituting DependentTy can't fail"
) ? static_cast<void> (0) : __assert_fail ("!Result.isNull() && \"substituting DependentTy can't fail\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4503, __PRETTY_FUNCTION__)); 4504 return DAR_Succeeded; 4505 } 4506 if (diagnoseAutoDeductionFailure(*this, TDK, Info, Ranges)) 4507 return DAR_FailedAlreadyDiagnosed; 4508 return DAR_Failed; 4509 }; 4510 4511 SmallVector<OriginalCallArg, 4> OriginalCallArgs; 4512 4513 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 4514 if (InitList) { 4515 // Notionally, we substitute std::initializer_list<T> for 'auto' and deduce 4516 // against that. Such deduction only succeeds if removing cv-qualifiers and 4517 // references results in std::initializer_list<T>. 4518 if (!Type.getType().getNonReferenceType()->getAs<AutoType>()) 4519 return DAR_Failed; 4520 4521 // Resolving a core issue: a braced-init-list containing any designators is 4522 // a non-deduced context. 4523 for (Expr *E : InitList->inits()) 4524 if (isa<DesignatedInitExpr>(E)) 4525 return DAR_Failed; 4526 4527 SourceRange DeducedFromInitRange; 4528 for (unsigned i = 0, e = InitList->getNumInits(); i < e; ++i) { 4529 Expr *Init = InitList->getInit(i); 4530 4531 if (auto TDK = DeduceTemplateArgumentsFromCallArgument( 4532 *this, TemplateParamsSt.get(), 0, TemplArg, Init, 4533 Info, Deduced, OriginalCallArgs, /*Decomposed*/ true, 4534 /*ArgIdx*/ 0, /*TDF*/ 0)) 4535 return DeductionFailed(TDK, {DeducedFromInitRange, 4536 Init->getSourceRange()}); 4537 4538 if (DeducedFromInitRange.isInvalid() && 4539 Deduced[0].getKind() != TemplateArgument::Null) 4540 DeducedFromInitRange = Init->getSourceRange(); 4541 } 4542 } else { 4543 if (!getLangOpts().CPlusPlus && Init->refersToBitField()) { 4544 Diag(Loc, diag::err_auto_bitfield); 4545 return DAR_FailedAlreadyDiagnosed; 4546 } 4547 4548 if (auto TDK = DeduceTemplateArgumentsFromCallArgument( 4549 *this, TemplateParamsSt.get(), 0, FuncParam, Init, Info, Deduced, 4550 OriginalCallArgs, /*Decomposed*/ false, /*ArgIdx*/ 0, /*TDF*/ 0)) 4551 return DeductionFailed(TDK, {}); 4552 } 4553 4554 // Could be null if somehow 'auto' appears in a non-deduced context. 4555 if (Deduced[0].getKind() != TemplateArgument::Type) 4556 return DeductionFailed(TDK_Incomplete, {}); 4557 4558 QualType DeducedType = Deduced[0].getAsType(); 4559 4560 if (InitList) { 4561 DeducedType = BuildStdInitializerList(DeducedType, Loc); 4562 if (DeducedType.isNull()) 4563 return DAR_FailedAlreadyDiagnosed; 4564 } 4565 4566 Result = SubstituteDeducedTypeTransform(*this, DeducedType).Apply(Type); 4567 if (Result.isNull()) 4568 return DAR_FailedAlreadyDiagnosed; 4569 4570 // Check that the deduced argument type is compatible with the original 4571 // argument type per C++ [temp.deduct.call]p4. 4572 QualType DeducedA = InitList ? Deduced[0].getAsType() : Result; 4573 for (const OriginalCallArg &OriginalArg : OriginalCallArgs) { 4574 assert((bool)InitList == OriginalArg.DecomposedParam &&(((bool)InitList == OriginalArg.DecomposedParam && "decomposed non-init-list in auto deduction?"
) ? static_cast<void> (0) : __assert_fail ("(bool)InitList == OriginalArg.DecomposedParam && \"decomposed non-init-list in auto deduction?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4575, __PRETTY_FUNCTION__)) 4575 "decomposed non-init-list in auto deduction?")(((bool)InitList == OriginalArg.DecomposedParam && "decomposed non-init-list in auto deduction?"
) ? static_cast<void> (0) : __assert_fail ("(bool)InitList == OriginalArg.DecomposedParam && \"decomposed non-init-list in auto deduction?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4575, __PRETTY_FUNCTION__)); 4576 if (auto TDK = 4577 CheckOriginalCallArgDeduction(*this, Info, OriginalArg, DeducedA)) { 4578 Result = QualType(); 4579 return DeductionFailed(TDK, {}); 4580 } 4581 } 4582 4583 return DAR_Succeeded; 4584} 4585 4586QualType Sema::SubstAutoType(QualType TypeWithAuto, 4587 QualType TypeToReplaceAuto) { 4588 if (TypeToReplaceAuto->isDependentType()) 4589 return SubstituteDeducedTypeTransform( 4590 *this, DependentAuto{ 4591 TypeToReplaceAuto->containsUnexpandedParameterPack()}) 4592 .TransformType(TypeWithAuto); 4593 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto) 4594 .TransformType(TypeWithAuto); 4595} 4596 4597TypeSourceInfo *Sema::SubstAutoTypeSourceInfo(TypeSourceInfo *TypeWithAuto, 4598 QualType TypeToReplaceAuto) { 4599 if (TypeToReplaceAuto->isDependentType()) 4600 return SubstituteDeducedTypeTransform( 4601 *this, 4602 DependentAuto{ 4603 TypeToReplaceAuto->containsUnexpandedParameterPack()}) 4604 .TransformType(TypeWithAuto); 4605 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto) 4606 .TransformType(TypeWithAuto); 4607} 4608 4609QualType Sema::ReplaceAutoType(QualType TypeWithAuto, 4610 QualType TypeToReplaceAuto) { 4611 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto, 4612 /*UseTypeSugar*/ false) 4613 .TransformType(TypeWithAuto); 4614} 4615 4616void Sema::DiagnoseAutoDeductionFailure(VarDecl *VDecl, Expr *Init) { 4617 if (isa<InitListExpr>(Init)) 4618 Diag(VDecl->getLocation(), 4619 VDecl->isInitCapture() 4620 ? diag::err_init_capture_deduction_failure_from_init_list 4621 : diag::err_auto_var_deduction_failure_from_init_list) 4622 << VDecl->getDeclName() << VDecl->getType() << Init->getSourceRange(); 4623 else 4624 Diag(VDecl->getLocation(), 4625 VDecl->isInitCapture() ? diag::err_init_capture_deduction_failure 4626 : diag::err_auto_var_deduction_failure) 4627 << VDecl->getDeclName() << VDecl->getType() << Init->getType() 4628 << Init->getSourceRange(); 4629} 4630 4631bool Sema::DeduceReturnType(FunctionDecl *FD, SourceLocation Loc, 4632 bool Diagnose) { 4633 assert(FD->getReturnType()->isUndeducedType())((FD->getReturnType()->isUndeducedType()) ? static_cast
<void> (0) : __assert_fail ("FD->getReturnType()->isUndeducedType()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4633, __PRETTY_FUNCTION__)); 4634 4635 // For a lambda's conversion operator, deduce any 'auto' or 'decltype(auto)' 4636 // within the return type from the call operator's type. 4637 if (isLambdaConversionOperator(FD)) { 4638 CXXRecordDecl *Lambda = cast<CXXMethodDecl>(FD)->getParent(); 4639 FunctionDecl *CallOp = Lambda->getLambdaCallOperator(); 4640 4641 // For a generic lambda, instantiate the call operator if needed. 4642 if (auto *Args = FD->getTemplateSpecializationArgs()) { 4643 CallOp = InstantiateFunctionDeclaration( 4644 CallOp->getDescribedFunctionTemplate(), Args, Loc); 4645 if (!CallOp || CallOp->isInvalidDecl()) 4646 return true; 4647 4648 // We might need to deduce the return type by instantiating the definition 4649 // of the operator() function. 4650 if (CallOp->getReturnType()->isUndeducedType()) { 4651 runWithSufficientStackSpace(Loc, [&] { 4652 InstantiateFunctionDefinition(Loc, CallOp); 4653 }); 4654 } 4655 } 4656 4657 if (CallOp->isInvalidDecl()) 4658 return true; 4659 assert(!CallOp->getReturnType()->isUndeducedType() &&((!CallOp->getReturnType()->isUndeducedType() &&
"failed to deduce lambda return type") ? static_cast<void
> (0) : __assert_fail ("!CallOp->getReturnType()->isUndeducedType() && \"failed to deduce lambda return type\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4660, __PRETTY_FUNCTION__)) 4660 "failed to deduce lambda return type")((!CallOp->getReturnType()->isUndeducedType() &&
"failed to deduce lambda return type") ? static_cast<void
> (0) : __assert_fail ("!CallOp->getReturnType()->isUndeducedType() && \"failed to deduce lambda return type\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4660, __PRETTY_FUNCTION__)); 4661 4662 // Build the new return type from scratch. 4663 QualType RetType = getLambdaConversionFunctionResultType( 4664 CallOp->getType()->castAs<FunctionProtoType>()); 4665 if (FD->getReturnType()->getAs<PointerType>()) 4666 RetType = Context.getPointerType(RetType); 4667 else { 4668 assert(FD->getReturnType()->getAs<BlockPointerType>())((FD->getReturnType()->getAs<BlockPointerType>())
? static_cast<void> (0) : __assert_fail ("FD->getReturnType()->getAs<BlockPointerType>()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4668, __PRETTY_FUNCTION__)); 4669 RetType = Context.getBlockPointerType(RetType); 4670 } 4671 Context.adjustDeducedFunctionResultType(FD, RetType); 4672 return false; 4673 } 4674 4675 if (FD->getTemplateInstantiationPattern()) { 4676 runWithSufficientStackSpace(Loc, [&] { 4677 InstantiateFunctionDefinition(Loc, FD); 4678 }); 4679 } 4680 4681 bool StillUndeduced = FD->getReturnType()->isUndeducedType(); 4682 if (StillUndeduced && Diagnose && !FD->isInvalidDecl()) { 4683 Diag(Loc, diag::err_auto_fn_used_before_defined) << FD; 4684 Diag(FD->getLocation(), diag::note_callee_decl) << FD; 4685 } 4686 4687 return StillUndeduced; 4688} 4689 4690/// If this is a non-static member function, 4691static void 4692AddImplicitObjectParameterType(ASTContext &Context, 4693 CXXMethodDecl *Method, 4694 SmallVectorImpl<QualType> &ArgTypes) { 4695 // C++11 [temp.func.order]p3: 4696 // [...] The new parameter is of type "reference to cv A," where cv are 4697 // the cv-qualifiers of the function template (if any) and A is 4698 // the class of which the function template is a member. 4699 // 4700 // The standard doesn't say explicitly, but we pick the appropriate kind of 4701 // reference type based on [over.match.funcs]p4. 4702 QualType ArgTy = Context.getTypeDeclType(Method->getParent()); 4703 ArgTy = Context.getQualifiedType(ArgTy, Method->getMethodQualifiers()); 4704 if (Method->getRefQualifier() == RQ_RValue) 4705 ArgTy = Context.getRValueReferenceType(ArgTy); 4706 else 4707 ArgTy = Context.getLValueReferenceType(ArgTy); 4708 ArgTypes.push_back(ArgTy); 4709} 4710 4711/// Determine whether the function template \p FT1 is at least as 4712/// specialized as \p FT2. 4713static bool isAtLeastAsSpecializedAs(Sema &S, 4714 SourceLocation Loc, 4715 FunctionTemplateDecl *FT1, 4716 FunctionTemplateDecl *FT2, 4717 TemplatePartialOrderingContext TPOC, 4718 unsigned NumCallArguments1) { 4719 FunctionDecl *FD1 = FT1->getTemplatedDecl(); 4720 FunctionDecl *FD2 = FT2->getTemplatedDecl(); 4721 const FunctionProtoType *Proto1 = FD1->getType()->getAs<FunctionProtoType>(); 4722 const FunctionProtoType *Proto2 = FD2->getType()->getAs<FunctionProtoType>(); 4723 4724 assert(Proto1 && Proto2 && "Function templates must have prototypes")((Proto1 && Proto2 && "Function templates must have prototypes"
) ? static_cast<void> (0) : __assert_fail ("Proto1 && Proto2 && \"Function templates must have prototypes\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4724, __PRETTY_FUNCTION__)); 4725 TemplateParameterList *TemplateParams = FT2->getTemplateParameters(); 4726 SmallVector<DeducedTemplateArgument, 4> Deduced; 4727 Deduced.resize(TemplateParams->size()); 4728 4729 // C++0x [temp.deduct.partial]p3: 4730 // The types used to determine the ordering depend on the context in which 4731 // the partial ordering is done: 4732 TemplateDeductionInfo Info(Loc); 4733 SmallVector<QualType, 4> Args2; 4734 switch (TPOC) { 4735 case TPOC_Call: { 4736 // - In the context of a function call, the function parameter types are 4737 // used. 4738 CXXMethodDecl *Method1 = dyn_cast<CXXMethodDecl>(FD1); 4739 CXXMethodDecl *Method2 = dyn_cast<CXXMethodDecl>(FD2); 4740 4741 // C++11 [temp.func.order]p3: 4742 // [...] If only one of the function templates is a non-static 4743 // member, that function template is considered to have a new 4744 // first parameter inserted in its function parameter list. The 4745 // new parameter is of type "reference to cv A," where cv are 4746 // the cv-qualifiers of the function template (if any) and A is 4747 // the class of which the function template is a member. 4748 // 4749 // Note that we interpret this to mean "if one of the function 4750 // templates is a non-static member and the other is a non-member"; 4751 // otherwise, the ordering rules for static functions against non-static 4752 // functions don't make any sense. 4753 // 4754 // C++98/03 doesn't have this provision but we've extended DR532 to cover 4755 // it as wording was broken prior to it. 4756 SmallVector<QualType, 4> Args1; 4757 4758 unsigned NumComparedArguments = NumCallArguments1; 4759 4760 if (!Method2 && Method1 && !Method1->isStatic()) { 4761 // Compare 'this' from Method1 against first parameter from Method2. 4762 AddImplicitObjectParameterType(S.Context, Method1, Args1); 4763 ++NumComparedArguments; 4764 } else if (!Method1 && Method2 && !Method2->isStatic()) { 4765 // Compare 'this' from Method2 against first parameter from Method1. 4766 AddImplicitObjectParameterType(S.Context, Method2, Args2); 4767 } 4768 4769 Args1.insert(Args1.end(), Proto1->param_type_begin(), 4770 Proto1->param_type_end()); 4771 Args2.insert(Args2.end(), Proto2->param_type_begin(), 4772 Proto2->param_type_end()); 4773 4774 // C++ [temp.func.order]p5: 4775 // The presence of unused ellipsis and default arguments has no effect on 4776 // the partial ordering of function templates. 4777 if (Args1.size() > NumComparedArguments) 4778 Args1.resize(NumComparedArguments); 4779 if (Args2.size() > NumComparedArguments) 4780 Args2.resize(NumComparedArguments); 4781 if (DeduceTemplateArguments(S, TemplateParams, Args2.data(), Args2.size(), 4782 Args1.data(), Args1.size(), Info, Deduced, 4783 TDF_None, /*PartialOrdering=*/true)) 4784 return false; 4785 4786 break; 4787 } 4788 4789 case TPOC_Conversion: 4790 // - In the context of a call to a conversion operator, the return types 4791 // of the conversion function templates are used. 4792 if (DeduceTemplateArgumentsByTypeMatch( 4793 S, TemplateParams, Proto2->getReturnType(), Proto1->getReturnType(), 4794 Info, Deduced, TDF_None, 4795 /*PartialOrdering=*/true)) 4796 return false; 4797 break; 4798 4799 case TPOC_Other: 4800 // - In other contexts (14.6.6.2) the function template's function type 4801 // is used. 4802 if (DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 4803 FD2->getType(), FD1->getType(), 4804 Info, Deduced, TDF_None, 4805 /*PartialOrdering=*/true)) 4806 return false; 4807 break; 4808 } 4809 4810 // C++0x [temp.deduct.partial]p11: 4811 // In most cases, all template parameters must have values in order for 4812 // deduction to succeed, but for partial ordering purposes a template 4813 // parameter may remain without a value provided it is not used in the 4814 // types being used for partial ordering. [ Note: a template parameter used 4815 // in a non-deduced context is considered used. -end note] 4816 unsigned ArgIdx = 0, NumArgs = Deduced.size(); 4817 for (; ArgIdx != NumArgs; ++ArgIdx) 4818 if (Deduced[ArgIdx].isNull()) 4819 break; 4820 4821 // FIXME: We fail to implement [temp.deduct.type]p1 along this path. We need 4822 // to substitute the deduced arguments back into the template and check that 4823 // we get the right type. 4824 4825 if (ArgIdx == NumArgs) { 4826 // All template arguments were deduced. FT1 is at least as specialized 4827 // as FT2. 4828 return true; 4829 } 4830 4831 // Figure out which template parameters were used. 4832 llvm::SmallBitVector UsedParameters(TemplateParams->size()); 4833 switch (TPOC) { 4834 case TPOC_Call: 4835 for (unsigned I = 0, N = Args2.size(); I != N; ++I) 4836 ::MarkUsedTemplateParameters(S.Context, Args2[I], false, 4837 TemplateParams->getDepth(), 4838 UsedParameters); 4839 break; 4840 4841 case TPOC_Conversion: 4842 ::MarkUsedTemplateParameters(S.Context, Proto2->getReturnType(), false, 4843 TemplateParams->getDepth(), UsedParameters); 4844 break; 4845 4846 case TPOC_Other: 4847 ::MarkUsedTemplateParameters(S.Context, FD2->getType(), false, 4848 TemplateParams->getDepth(), 4849 UsedParameters); 4850 break; 4851 } 4852 4853 for (; ArgIdx != NumArgs; ++ArgIdx) 4854 // If this argument had no value deduced but was used in one of the types 4855 // used for partial ordering, then deduction fails. 4856 if (Deduced[ArgIdx].isNull() && UsedParameters[ArgIdx]) 4857 return false; 4858 4859 return true; 4860} 4861 4862/// Determine whether this a function template whose parameter-type-list 4863/// ends with a function parameter pack. 4864static bool isVariadicFunctionTemplate(FunctionTemplateDecl *FunTmpl) { 4865 FunctionDecl *Function = FunTmpl->getTemplatedDecl(); 4866 unsigned NumParams = Function->getNumParams(); 4867 if (NumParams == 0) 4868 return false; 4869 4870 ParmVarDecl *Last = Function->getParamDecl(NumParams - 1); 4871 if (!Last->isParameterPack()) 4872 return false; 4873 4874 // Make sure that no previous parameter is a parameter pack. 4875 while (--NumParams > 0) { 4876 if (Function->getParamDecl(NumParams - 1)->isParameterPack()) 4877 return false; 4878 } 4879 4880 return true; 4881} 4882 4883/// Returns the more specialized function template according 4884/// to the rules of function template partial ordering (C++ [temp.func.order]). 4885/// 4886/// \param FT1 the first function template 4887/// 4888/// \param FT2 the second function template 4889/// 4890/// \param TPOC the context in which we are performing partial ordering of 4891/// function templates. 4892/// 4893/// \param NumCallArguments1 The number of arguments in the call to FT1, used 4894/// only when \c TPOC is \c TPOC_Call. 4895/// 4896/// \param NumCallArguments2 The number of arguments in the call to FT2, used 4897/// only when \c TPOC is \c TPOC_Call. 4898/// 4899/// \returns the more specialized function template. If neither 4900/// template is more specialized, returns NULL. 4901FunctionTemplateDecl * 4902Sema::getMoreSpecializedTemplate(FunctionTemplateDecl *FT1, 4903 FunctionTemplateDecl *FT2, 4904 SourceLocation Loc, 4905 TemplatePartialOrderingContext TPOC, 4906 unsigned NumCallArguments1, 4907 unsigned NumCallArguments2) { 4908 bool Better1 = isAtLeastAsSpecializedAs(*this, Loc, FT1, FT2, TPOC, 4909 NumCallArguments1); 4910 bool Better2 = isAtLeastAsSpecializedAs(*this, Loc, FT2, FT1, TPOC, 4911 NumCallArguments2); 4912 4913 if (Better1 != Better2) // We have a clear winner 4914 return Better1 ? FT1 : FT2; 4915 4916 if (!Better1 && !Better2) // Neither is better than the other 4917 return nullptr; 4918 4919 // FIXME: This mimics what GCC implements, but doesn't match up with the 4920 // proposed resolution for core issue 692. This area needs to be sorted out, 4921 // but for now we attempt to maintain compatibility. 4922 bool Variadic1 = isVariadicFunctionTemplate(FT1); 4923 bool Variadic2 = isVariadicFunctionTemplate(FT2); 4924 if (Variadic1 != Variadic2) 4925 return Variadic1? FT2 : FT1; 4926 4927 return nullptr; 4928} 4929 4930/// Determine if the two templates are equivalent. 4931static bool isSameTemplate(TemplateDecl *T1, TemplateDecl *T2) { 4932 if (T1 == T2) 4933 return true; 4934 4935 if (!T1 || !T2) 4936 return false; 4937 4938 return T1->getCanonicalDecl() == T2->getCanonicalDecl(); 4939} 4940 4941/// Retrieve the most specialized of the given function template 4942/// specializations. 4943/// 4944/// \param SpecBegin the start iterator of the function template 4945/// specializations that we will be comparing. 4946/// 4947/// \param SpecEnd the end iterator of the function template 4948/// specializations, paired with \p SpecBegin. 4949/// 4950/// \param Loc the location where the ambiguity or no-specializations 4951/// diagnostic should occur. 4952/// 4953/// \param NoneDiag partial diagnostic used to diagnose cases where there are 4954/// no matching candidates. 4955/// 4956/// \param AmbigDiag partial diagnostic used to diagnose an ambiguity, if one 4957/// occurs. 4958/// 4959/// \param CandidateDiag partial diagnostic used for each function template 4960/// specialization that is a candidate in the ambiguous ordering. One parameter 4961/// in this diagnostic should be unbound, which will correspond to the string 4962/// describing the template arguments for the function template specialization. 4963/// 4964/// \returns the most specialized function template specialization, if 4965/// found. Otherwise, returns SpecEnd. 4966UnresolvedSetIterator Sema::getMostSpecialized( 4967 UnresolvedSetIterator SpecBegin, UnresolvedSetIterator SpecEnd, 4968 TemplateSpecCandidateSet &FailedCandidates, 4969 SourceLocation Loc, const PartialDiagnostic &NoneDiag, 4970 const PartialDiagnostic &AmbigDiag, const PartialDiagnostic &CandidateDiag, 4971 bool Complain, QualType TargetType) { 4972 if (SpecBegin == SpecEnd) { 4973 if (Complain) { 4974 Diag(Loc, NoneDiag); 4975 FailedCandidates.NoteCandidates(*this, Loc); 4976 } 4977 return SpecEnd; 4978 } 4979 4980 if (SpecBegin + 1 == SpecEnd) 4981 return SpecBegin; 4982 4983 // Find the function template that is better than all of the templates it 4984 // has been compared to. 4985 UnresolvedSetIterator Best = SpecBegin; 4986 FunctionTemplateDecl *BestTemplate 4987 = cast<FunctionDecl>(*Best)->getPrimaryTemplate(); 4988 assert(BestTemplate && "Not a function template specialization?")((BestTemplate && "Not a function template specialization?"
) ? static_cast<void> (0) : __assert_fail ("BestTemplate && \"Not a function template specialization?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4988, __PRETTY_FUNCTION__)); 4989 for (UnresolvedSetIterator I = SpecBegin + 1; I != SpecEnd; ++I) { 4990 FunctionTemplateDecl *Challenger 4991 = cast<FunctionDecl>(*I)->getPrimaryTemplate(); 4992 assert(Challenger && "Not a function template specialization?")((Challenger && "Not a function template specialization?"
) ? static_cast<void> (0) : __assert_fail ("Challenger && \"Not a function template specialization?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4992, __PRETTY_FUNCTION__)); 4993 if (isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger, 4994 Loc, TPOC_Other, 0, 0), 4995 Challenger)) { 4996 Best = I; 4997 BestTemplate = Challenger; 4998 } 4999 } 5000 5001 // Make sure that the "best" function template is more specialized than all 5002 // of the others. 5003 bool Ambiguous = false; 5004 for (UnresolvedSetIterator I = SpecBegin; I != SpecEnd; ++I) { 5005 FunctionTemplateDecl *Challenger 5006 = cast<FunctionDecl>(*I)->getPrimaryTemplate(); 5007 if (I != Best && 5008 !isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger, 5009 Loc, TPOC_Other, 0, 0), 5010 BestTemplate)) { 5011 Ambiguous = true; 5012 break; 5013 } 5014 } 5015 5016 if (!Ambiguous) { 5017 // We found an answer. Return it. 5018 return Best; 5019 } 5020 5021 // Diagnose the ambiguity. 5022 if (Complain) { 5023 Diag(Loc, AmbigDiag); 5024 5025 // FIXME: Can we order the candidates in some sane way? 5026 for (UnresolvedSetIterator I = SpecBegin; I != SpecEnd; ++I) { 5027 PartialDiagnostic PD = CandidateDiag; 5028 const auto *FD = cast<FunctionDecl>(*I); 5029 PD << FD << getTemplateArgumentBindingsText( 5030 FD->getPrimaryTemplate()->getTemplateParameters(), 5031 *FD->getTemplateSpecializationArgs()); 5032 if (!TargetType.isNull()) 5033 HandleFunctionTypeMismatch(PD, FD->getType(), TargetType); 5034 Diag((*I)->getLocation(), PD); 5035 } 5036 } 5037 5038 return SpecEnd; 5039} 5040 5041/// Determine whether one partial specialization, P1, is at least as 5042/// specialized than another, P2. 5043/// 5044/// \tparam TemplateLikeDecl The kind of P2, which must be a 5045/// TemplateDecl or {Class,Var}TemplatePartialSpecializationDecl. 5046/// \param T1 The injected-class-name of P1 (faked for a variable template). 5047/// \param T2 The injected-class-name of P2 (faked for a variable template). 5048template<typename TemplateLikeDecl> 5049static bool isAtLeastAsSpecializedAs(Sema &S, QualType T1, QualType T2, 5050 TemplateLikeDecl *P2, 5051 TemplateDeductionInfo &Info) { 5052 // C++ [temp.class.order]p1: 5053 // For two class template partial specializations, the first is at least as 5054 // specialized as the second if, given the following rewrite to two 5055 // function templates, the first function template is at least as 5056 // specialized as the second according to the ordering rules for function 5057 // templates (14.6.6.2): 5058 // - the first function template has the same template parameters as the 5059 // first partial specialization and has a single function parameter 5060 // whose type is a class template specialization with the template 5061 // arguments of the first partial specialization, and 5062 // - the second function template has the same template parameters as the 5063 // second partial specialization and has a single function parameter 5064 // whose type is a class template specialization with the template 5065 // arguments of the second partial specialization. 5066 // 5067 // Rather than synthesize function templates, we merely perform the 5068 // equivalent partial ordering by performing deduction directly on 5069 // the template arguments of the class template partial 5070 // specializations. This computation is slightly simpler than the 5071 // general problem of function template partial ordering, because 5072 // class template partial specializations are more constrained. We 5073 // know that every template parameter is deducible from the class 5074 // template partial specialization's template arguments, for 5075 // example. 5076 SmallVector<DeducedTemplateArgument, 4> Deduced; 5077 5078 // Determine whether P1 is at least as specialized as P2. 5079 Deduced.resize(P2->getTemplateParameters()->size()); 5080 if (DeduceTemplateArgumentsByTypeMatch(S, P2->getTemplateParameters(), 5081 T2, T1, Info, Deduced, TDF_None, 5082 /*PartialOrdering=*/true)) 5083 return false; 5084 5085 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), 5086 Deduced.end()); 5087 Sema::InstantiatingTemplate Inst(S, Info.getLocation(), P2, DeducedArgs, 5088 Info); 5089 auto *TST1 = T1->castAs<TemplateSpecializationType>(); 5090 if (FinishTemplateArgumentDeduction( 5091 S, P2, /*IsPartialOrdering=*/true, 5092 TemplateArgumentList(TemplateArgumentList::OnStack, 5093 TST1->template_arguments()), 5094 Deduced, Info)) 5095 return false; 5096 5097 return true; 5098} 5099 5100/// Returns the more specialized class template partial specialization 5101/// according to the rules of partial ordering of class template partial 5102/// specializations (C++ [temp.class.order]). 5103/// 5104/// \param PS1 the first class template partial specialization 5105/// 5106/// \param PS2 the second class template partial specialization 5107/// 5108/// \returns the more specialized class template partial specialization. If 5109/// neither partial specialization is more specialized, returns NULL. 5110ClassTemplatePartialSpecializationDecl * 5111Sema::getMoreSpecializedPartialSpecialization( 5112 ClassTemplatePartialSpecializationDecl *PS1, 5113 ClassTemplatePartialSpecializationDecl *PS2, 5114 SourceLocation Loc) { 5115 QualType PT1 = PS1->getInjectedSpecializationType(); 5116 QualType PT2 = PS2->getInjectedSpecializationType(); 5117 5118 TemplateDeductionInfo Info(Loc); 5119 bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info); 5120 bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info); 5121 5122 if (Better1 == Better2) 5123 return nullptr; 5124 5125 return Better1 ? PS1 : PS2; 5126} 5127 5128bool Sema::isMoreSpecializedThanPrimary( 5129 ClassTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo &Info) { 5130 ClassTemplateDecl *Primary = Spec->getSpecializedTemplate(); 5131 QualType PrimaryT = Primary->getInjectedClassNameSpecialization(); 5132 QualType PartialT = Spec->getInjectedSpecializationType(); 5133 if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info)) 5134 return false; 5135 if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) { 5136 Info.clearSFINAEDiagnostic(); 5137 return false; 5138 } 5139 return true; 5140} 5141 5142VarTemplatePartialSpecializationDecl * 5143Sema::getMoreSpecializedPartialSpecialization( 5144 VarTemplatePartialSpecializationDecl *PS1, 5145 VarTemplatePartialSpecializationDecl *PS2, SourceLocation Loc) { 5146 // Pretend the variable template specializations are class template 5147 // specializations and form a fake injected class name type for comparison. 5148 assert(PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() &&((PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate
() && "the partial specializations being compared should specialize"
" the same template.") ? static_cast<void> (0) : __assert_fail
("PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() && \"the partial specializations being compared should specialize\" \" the same template.\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5150, __PRETTY_FUNCTION__)) 5149 "the partial specializations being compared should specialize"((PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate
() && "the partial specializations being compared should specialize"
" the same template.") ? static_cast<void> (0) : __assert_fail
("PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() && \"the partial specializations being compared should specialize\" \" the same template.\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5150, __PRETTY_FUNCTION__)) 5150 " the same template.")((PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate
() && "the partial specializations being compared should specialize"
" the same template.") ? static_cast<void> (0) : __assert_fail
("PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() && \"the partial specializations being compared should specialize\" \" the same template.\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5150, __PRETTY_FUNCTION__)); 5151 TemplateName Name(PS1->getSpecializedTemplate()); 5152 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name); 5153 QualType PT1 = Context.getTemplateSpecializationType( 5154 CanonTemplate, PS1->getTemplateArgs().asArray()); 5155 QualType PT2 = Context.getTemplateSpecializationType( 5156 CanonTemplate, PS2->getTemplateArgs().asArray()); 5157 5158 TemplateDeductionInfo Info(Loc); 5159 bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info); 5160 bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info); 5161 5162 if (Better1 == Better2) 5163 return nullptr; 5164 5165 return Better1 ? PS1 : PS2; 5166} 5167 5168bool Sema::isMoreSpecializedThanPrimary( 5169 VarTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo &Info) { 5170 TemplateDecl *Primary = Spec->getSpecializedTemplate(); 5171 // FIXME: Cache the injected template arguments rather than recomputing 5172 // them for each partial specialization. 5173 SmallVector<TemplateArgument, 8> PrimaryArgs; 5174 Context.getInjectedTemplateArgs(Primary->getTemplateParameters(), 5175 PrimaryArgs); 5176 5177 TemplateName CanonTemplate = 5178 Context.getCanonicalTemplateName(TemplateName(Primary)); 5179 QualType PrimaryT = Context.getTemplateSpecializationType( 5180 CanonTemplate, PrimaryArgs); 5181 QualType PartialT = Context.getTemplateSpecializationType( 5182 CanonTemplate, Spec->getTemplateArgs().asArray()); 5183 if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info)) 5184 return false; 5185 if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) { 5186 Info.clearSFINAEDiagnostic(); 5187 return false; 5188 } 5189 return true; 5190} 5191 5192bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs( 5193 TemplateParameterList *P, TemplateDecl *AArg, SourceLocation Loc) { 5194 // C++1z [temp.arg.template]p4: (DR 150) 5195 // A template template-parameter P is at least as specialized as a 5196 // template template-argument A if, given the following rewrite to two 5197 // function templates... 5198 5199 // Rather than synthesize function templates, we merely perform the 5200 // equivalent partial ordering by performing deduction directly on 5201 // the template parameter lists of the template template parameters. 5202 // 5203 // Given an invented class template X with the template parameter list of 5204 // A (including default arguments): 5205 TemplateName X = Context.getCanonicalTemplateName(TemplateName(AArg)); 5206 TemplateParameterList *A = AArg->getTemplateParameters(); 5207 5208 // - Each function template has a single function parameter whose type is 5209 // a specialization of X with template arguments corresponding to the 5210 // template parameters from the respective function template 5211 SmallVector<TemplateArgument, 8> AArgs; 5212 Context.getInjectedTemplateArgs(A, AArgs); 5213 5214 // Check P's arguments against A's parameter list. This will fill in default 5215 // template arguments as needed. AArgs are already correct by construction. 5216 // We can't just use CheckTemplateIdType because that will expand alias 5217 // templates. 5218 SmallVector<TemplateArgument, 4> PArgs; 5219 { 5220 SFINAETrap Trap(*this); 5221 5222 Context.getInjectedTemplateArgs(P, PArgs); 5223 TemplateArgumentListInfo PArgList(P->getLAngleLoc(), P->getRAngleLoc()); 5224 for (unsigned I = 0, N = P->size(); I != N; ++I) { 5225 // Unwrap packs that getInjectedTemplateArgs wrapped around pack 5226 // expansions, to form an "as written" argument list. 5227 TemplateArgument Arg = PArgs[I]; 5228 if (Arg.getKind() == TemplateArgument::Pack) { 5229 assert(Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion())((Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion
()) ? static_cast<void> (0) : __assert_fail ("Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5229, __PRETTY_FUNCTION__)); 5230 Arg = *Arg.pack_begin(); 5231 } 5232 PArgList.addArgument(getTrivialTemplateArgumentLoc( 5233 Arg, QualType(), P->getParam(I)->getLocation())); 5234 } 5235 PArgs.clear(); 5236 5237 // C++1z [temp.arg.template]p3: 5238 // If the rewrite produces an invalid type, then P is not at least as 5239 // specialized as A. 5240 if (CheckTemplateArgumentList(AArg, Loc, PArgList, false, PArgs) || 5241 Trap.hasErrorOccurred()) 5242 return false; 5243 } 5244 5245 QualType AType = Context.getTemplateSpecializationType(X, AArgs); 5246 QualType PType = Context.getTemplateSpecializationType(X, PArgs); 5247 5248 // ... the function template corresponding to P is at least as specialized 5249 // as the function template corresponding to A according to the partial 5250 // ordering rules for function templates. 5251 TemplateDeductionInfo Info(Loc, A->getDepth()); 5252 return isAtLeastAsSpecializedAs(*this, PType, AType, AArg, Info); 5253} 5254 5255/// Mark the template parameters that are used by the given 5256/// expression. 5257static void 5258MarkUsedTemplateParameters(ASTContext &Ctx, 5259 const Expr *E, 5260 bool OnlyDeduced, 5261 unsigned Depth, 5262 llvm::SmallBitVector &Used) { 5263 // We can deduce from a pack expansion. 5264 if (const PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(E)) 5265 E = Expansion->getPattern(); 5266 5267 // Skip through any implicit casts we added while type-checking, and any 5268 // substitutions performed by template alias expansion. 5269 while (true) { 5270 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) 5271 E = ICE->getSubExpr(); 5272 else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(E)) 5273 E = CE->getSubExpr(); 5274 else if (const SubstNonTypeTemplateParmExpr *Subst = 5275 dyn_cast<SubstNonTypeTemplateParmExpr>(E)) 5276 E = Subst->getReplacement(); 5277 else 5278 break; 5279 } 5280 5281 // FIXME: if !OnlyDeduced, we have to walk the whole subexpression to 5282 // find other occurrences of template parameters. 5283 const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E); 5284 if (!DRE) 5285 return; 5286 5287 const NonTypeTemplateParmDecl *NTTP 5288 = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl()); 5289 if (!NTTP) 5290 return; 5291 5292 if (NTTP->getDepth() == Depth) 5293 Used[NTTP->getIndex()] = true; 5294 5295 // In C++17 mode, additional arguments may be deduced from the type of a 5296 // non-type argument. 5297 if (Ctx.getLangOpts().CPlusPlus17) 5298 MarkUsedTemplateParameters(Ctx, NTTP->getType(), OnlyDeduced, Depth, Used); 5299} 5300 5301/// Mark the template parameters that are used by the given 5302/// nested name specifier. 5303static void 5304MarkUsedTemplateParameters(ASTContext &Ctx, 5305 NestedNameSpecifier *NNS, 5306 bool OnlyDeduced, 5307 unsigned Depth, 5308 llvm::SmallBitVector &Used) { 5309 if (!NNS) 5310 return; 5311 5312 MarkUsedTemplateParameters(Ctx, NNS->getPrefix(), OnlyDeduced, Depth, 5313 Used); 5314 MarkUsedTemplateParameters(Ctx, QualType(NNS->getAsType(), 0), 5315 OnlyDeduced, Depth, Used); 5316} 5317 5318/// Mark the template parameters that are used by the given 5319/// template name. 5320static void 5321MarkUsedTemplateParameters(ASTContext &Ctx, 5322 TemplateName Name, 5323 bool OnlyDeduced, 5324 unsigned Depth, 5325 llvm::SmallBitVector &Used) { 5326 if (TemplateDecl *Template = Name.getAsTemplateDecl()) { 5327 if (TemplateTemplateParmDecl *TTP 5328 = dyn_cast<TemplateTemplateParmDecl>(Template)) { 5329 if (TTP->getDepth() == Depth) 5330 Used[TTP->getIndex()] = true; 5331 } 5332 return; 5333 } 5334 5335 if (QualifiedTemplateName *QTN = Name.getAsQualifiedTemplateName()) 5336 MarkUsedTemplateParameters(Ctx, QTN->getQualifier(), OnlyDeduced, 5337 Depth, Used); 5338 if (DependentTemplateName *DTN = Name.getAsDependentTemplateName()) 5339 MarkUsedTemplateParameters(Ctx, DTN->getQualifier(), OnlyDeduced, 5340 Depth, Used); 5341} 5342 5343/// Mark the template parameters that are used by the given 5344/// type. 5345static void 5346MarkUsedTemplateParameters(ASTContext &Ctx, QualType T, 5347 bool OnlyDeduced, 5348 unsigned Depth, 5349 llvm::SmallBitVector &Used) { 5350 if (T.isNull()) 5351 return; 5352 5353 // Non-dependent types have nothing deducible 5354 if (!T->isDependentType()) 5355 return; 5356 5357 T = Ctx.getCanonicalType(T); 5358 switch (T->getTypeClass()) { 5359 case Type::Pointer: 5360 MarkUsedTemplateParameters(Ctx, 5361 cast<PointerType>(T)->getPointeeType(), 5362 OnlyDeduced, 5363 Depth, 5364 Used); 5365 break; 5366 5367 case Type::BlockPointer: 5368 MarkUsedTemplateParameters(Ctx, 5369 cast<BlockPointerType>(T)->getPointeeType(), 5370 OnlyDeduced, 5371 Depth, 5372 Used); 5373 break; 5374 5375 case Type::LValueReference: 5376 case Type::RValueReference: 5377 MarkUsedTemplateParameters(Ctx, 5378 cast<ReferenceType>(T)->getPointeeType(), 5379 OnlyDeduced, 5380 Depth, 5381 Used); 5382 break; 5383 5384 case Type::MemberPointer: { 5385 const MemberPointerType *MemPtr = cast<MemberPointerType>(T.getTypePtr()); 5386 MarkUsedTemplateParameters(Ctx, MemPtr->getPointeeType(), OnlyDeduced, 5387 Depth, Used); 5388 MarkUsedTemplateParameters(Ctx, QualType(MemPtr->getClass(), 0), 5389 OnlyDeduced, Depth, Used); 5390 break; 5391 } 5392 5393 case Type::DependentSizedArray: 5394 MarkUsedTemplateParameters(Ctx, 5395 cast<DependentSizedArrayType>(T)->getSizeExpr(), 5396 OnlyDeduced, Depth, Used); 5397 // Fall through to check the element type 5398 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 5399 5400 case Type::ConstantArray: 5401 case Type::IncompleteArray: 5402 MarkUsedTemplateParameters(Ctx, 5403 cast<ArrayType>(T)->getElementType(), 5404 OnlyDeduced, Depth, Used); 5405 break; 5406 5407 case Type::Vector: 5408 case Type::ExtVector: 5409 MarkUsedTemplateParameters(Ctx, 5410 cast<VectorType>(T)->getElementType(), 5411 OnlyDeduced, Depth, Used); 5412 break; 5413 5414 case Type::DependentVector: { 5415 const auto *VecType = cast<DependentVectorType>(T); 5416 MarkUsedTemplateParameters(Ctx, VecType->getElementType(), OnlyDeduced, 5417 Depth, Used); 5418 MarkUsedTemplateParameters(Ctx, VecType->getSizeExpr(), OnlyDeduced, Depth, 5419 Used); 5420 break; 5421 } 5422 case Type::DependentSizedExtVector: { 5423 const DependentSizedExtVectorType *VecType 5424 = cast<DependentSizedExtVectorType>(T); 5425 MarkUsedTemplateParameters(Ctx, VecType->getElementType(), OnlyDeduced, 5426 Depth, Used); 5427 MarkUsedTemplateParameters(Ctx, VecType->getSizeExpr(), OnlyDeduced, 5428 Depth, Used); 5429 break; 5430 } 5431 5432 case Type::DependentAddressSpace: { 5433 const DependentAddressSpaceType *DependentASType = 5434 cast<DependentAddressSpaceType>(T); 5435 MarkUsedTemplateParameters(Ctx, DependentASType->getPointeeType(), 5436 OnlyDeduced, Depth, Used); 5437 MarkUsedTemplateParameters(Ctx, 5438 DependentASType->getAddrSpaceExpr(), 5439 OnlyDeduced, Depth, Used); 5440 break; 5441 } 5442 5443 case Type::FunctionProto: { 5444 const FunctionProtoType *Proto = cast<FunctionProtoType>(T); 5445 MarkUsedTemplateParameters(Ctx, Proto->getReturnType(), OnlyDeduced, Depth, 5446 Used); 5447 for (unsigned I = 0, N = Proto->getNumParams(); I != N; ++I) { 5448 // C++17 [temp.deduct.type]p5: 5449 // The non-deduced contexts are: [...] 5450 // -- A function parameter pack that does not occur at the end of the 5451 // parameter-declaration-list. 5452 if (!OnlyDeduced || I + 1 == N || 5453 !Proto->getParamType(I)->getAs<PackExpansionType>()) { 5454 MarkUsedTemplateParameters(Ctx, Proto->getParamType(I), OnlyDeduced, 5455 Depth, Used); 5456 } else { 5457 // FIXME: C++17 [temp.deduct.call]p1: 5458 // When a function parameter pack appears in a non-deduced context, 5459 // the type of that pack is never deduced. 5460 // 5461 // We should also track a set of "never deduced" parameters, and 5462 // subtract that from the list of deduced parameters after marking. 5463 } 5464 } 5465 if (auto *E = Proto->getNoexceptExpr()) 5466 MarkUsedTemplateParameters(Ctx, E, OnlyDeduced, Depth, Used); 5467 break; 5468 } 5469 5470 case Type::TemplateTypeParm: { 5471 const TemplateTypeParmType *TTP = cast<TemplateTypeParmType>(T); 5472 if (TTP->getDepth() == Depth) 5473 Used[TTP->getIndex()] = true; 5474 break; 5475 } 5476 5477 case Type::SubstTemplateTypeParmPack: { 5478 const SubstTemplateTypeParmPackType *Subst 5479 = cast<SubstTemplateTypeParmPackType>(T); 5480 MarkUsedTemplateParameters(Ctx, 5481 QualType(Subst->getReplacedParameter(), 0), 5482 OnlyDeduced, Depth, Used); 5483 MarkUsedTemplateParameters(Ctx, Subst->getArgumentPack(), 5484 OnlyDeduced, Depth, Used); 5485 break; 5486 } 5487 5488 case Type::InjectedClassName: 5489 T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType(); 5490 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 5491 5492 case Type::TemplateSpecialization: { 5493 const TemplateSpecializationType *Spec 5494 = cast<TemplateSpecializationType>(T); 5495 MarkUsedTemplateParameters(Ctx, Spec->getTemplateName(), OnlyDeduced, 5496 Depth, Used); 5497 5498 // C++0x [temp.deduct.type]p9: 5499 // If the template argument list of P contains a pack expansion that is 5500 // not the last template argument, the entire template argument list is a 5501 // non-deduced context. 5502 if (OnlyDeduced && 5503 hasPackExpansionBeforeEnd(Spec->template_arguments())) 5504 break; 5505 5506 for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I) 5507 MarkUsedTemplateParameters(Ctx, Spec->getArg(I), OnlyDeduced, Depth, 5508 Used); 5509 break; 5510 } 5511 5512 case Type::Complex: 5513 if (!OnlyDeduced) 5514 MarkUsedTemplateParameters(Ctx, 5515 cast<ComplexType>(T)->getElementType(), 5516 OnlyDeduced, Depth, Used); 5517 break; 5518 5519 case Type::Atomic: 5520 if (!OnlyDeduced) 5521 MarkUsedTemplateParameters(Ctx, 5522 cast<AtomicType>(T)->getValueType(), 5523 OnlyDeduced, Depth, Used); 5524 break; 5525 5526 case Type::DependentName: 5527 if (!OnlyDeduced) 5528 MarkUsedTemplateParameters(Ctx, 5529 cast<DependentNameType>(T)->getQualifier(), 5530 OnlyDeduced, Depth, Used); 5531 break; 5532 5533 case Type::DependentTemplateSpecialization: { 5534 // C++14 [temp.deduct.type]p5: 5535 // The non-deduced contexts are: 5536 // -- The nested-name-specifier of a type that was specified using a 5537 // qualified-id 5538 // 5539 // C++14 [temp.deduct.type]p6: 5540 // When a type name is specified in a way that includes a non-deduced 5541 // context, all of the types that comprise that type name are also 5542 // non-deduced. 5543 if (OnlyDeduced) 5544 break; 5545 5546 const DependentTemplateSpecializationType *Spec 5547 = cast<DependentTemplateSpecializationType>(T); 5548 5549 MarkUsedTemplateParameters(Ctx, Spec->getQualifier(), 5550 OnlyDeduced, Depth, Used); 5551 5552 for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I) 5553 MarkUsedTemplateParameters(Ctx, Spec->getArg(I), OnlyDeduced, Depth, 5554 Used); 5555 break; 5556 } 5557 5558 case Type::TypeOf: 5559 if (!OnlyDeduced) 5560 MarkUsedTemplateParameters(Ctx, 5561 cast<TypeOfType>(T)->getUnderlyingType(), 5562 OnlyDeduced, Depth, Used); 5563 break; 5564 5565 case Type::TypeOfExpr: 5566 if (!OnlyDeduced) 5567 MarkUsedTemplateParameters(Ctx, 5568 cast<TypeOfExprType>(T)->getUnderlyingExpr(), 5569 OnlyDeduced, Depth, Used); 5570 break; 5571 5572 case Type::Decltype: 5573 if (!OnlyDeduced) 5574 MarkUsedTemplateParameters(Ctx, 5575 cast<DecltypeType>(T)->getUnderlyingExpr(), 5576 OnlyDeduced, Depth, Used); 5577 break; 5578 5579 case Type::UnaryTransform: 5580 if (!OnlyDeduced) 5581 MarkUsedTemplateParameters(Ctx, 5582 cast<UnaryTransformType>(T)->getUnderlyingType(), 5583 OnlyDeduced, Depth, Used); 5584 break; 5585 5586 case Type::PackExpansion: 5587 MarkUsedTemplateParameters(Ctx, 5588 cast<PackExpansionType>(T)->getPattern(), 5589 OnlyDeduced, Depth, Used); 5590 break; 5591 5592 case Type::Auto: 5593 case Type::DeducedTemplateSpecialization: 5594 MarkUsedTemplateParameters(Ctx, 5595 cast<DeducedType>(T)->getDeducedType(), 5596 OnlyDeduced, Depth, Used); 5597 break; 5598 5599 // None of these types have any template parameters in them. 5600 case Type::Builtin: 5601 case Type::VariableArray: 5602 case Type::FunctionNoProto: 5603 case Type::Record: 5604 case Type::Enum: 5605 case Type::ObjCInterface: 5606 case Type::ObjCObject: 5607 case Type::ObjCObjectPointer: 5608 case Type::UnresolvedUsing: 5609 case Type::Pipe: 5610#define TYPE(Class, Base) 5611#define ABSTRACT_TYPE(Class, Base) 5612#define DEPENDENT_TYPE(Class, Base) 5613#define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 5614#include "clang/AST/TypeNodes.inc" 5615 break; 5616 } 5617} 5618 5619/// Mark the template parameters that are used by this 5620/// template argument. 5621static void 5622MarkUsedTemplateParameters(ASTContext &Ctx, 5623 const TemplateArgument &TemplateArg, 5624 bool OnlyDeduced, 5625 unsigned Depth, 5626 llvm::SmallBitVector &Used) { 5627 switch (TemplateArg.getKind()) { 5628 case TemplateArgument::Null: 5629 case TemplateArgument::Integral: 5630 case TemplateArgument::Declaration: 5631 break; 5632 5633 case TemplateArgument::NullPtr: 5634 MarkUsedTemplateParameters(Ctx, TemplateArg.getNullPtrType(), OnlyDeduced, 5635 Depth, Used); 5636 break; 5637 5638 case TemplateArgument::Type: 5639 MarkUsedTemplateParameters(Ctx, TemplateArg.getAsType(), OnlyDeduced, 5640 Depth, Used); 5641 break; 5642 5643 case TemplateArgument::Template: 5644 case TemplateArgument::TemplateExpansion: 5645 MarkUsedTemplateParameters(Ctx, 5646 TemplateArg.getAsTemplateOrTemplatePattern(), 5647 OnlyDeduced, Depth, Used); 5648 break; 5649 5650 case TemplateArgument::Expression: 5651 MarkUsedTemplateParameters(Ctx, TemplateArg.getAsExpr(), OnlyDeduced, 5652 Depth, Used); 5653 break; 5654 5655 case TemplateArgument::Pack: 5656 for (const auto &P : TemplateArg.pack_elements()) 5657 MarkUsedTemplateParameters(Ctx, P, OnlyDeduced, Depth, Used); 5658 break; 5659 } 5660} 5661 5662/// Mark which template parameters can be deduced from a given 5663/// template argument list. 5664/// 5665/// \param TemplateArgs the template argument list from which template 5666/// parameters will be deduced. 5667/// 5668/// \param Used a bit vector whose elements will be set to \c true 5669/// to indicate when the corresponding template parameter will be 5670/// deduced. 5671void 5672Sema::MarkUsedTemplateParameters(const TemplateArgumentList &TemplateArgs, 5673 bool OnlyDeduced, unsigned Depth, 5674 llvm::SmallBitVector &Used) { 5675 // C++0x [temp.deduct.type]p9: 5676 // If the template argument list of P contains a pack expansion that is not 5677 // the last template argument, the entire template argument list is a 5678 // non-deduced context. 5679 if (OnlyDeduced && 5680 hasPackExpansionBeforeEnd(TemplateArgs.asArray())) 5681 return; 5682 5683 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 5684 ::MarkUsedTemplateParameters(Context, TemplateArgs[I], OnlyDeduced, 5685 Depth, Used); 5686} 5687 5688/// Marks all of the template parameters that will be deduced by a 5689/// call to the given function template. 5690void Sema::MarkDeducedTemplateParameters( 5691 ASTContext &Ctx, const FunctionTemplateDecl *FunctionTemplate, 5692 llvm::SmallBitVector &Deduced) { 5693 TemplateParameterList *TemplateParams 5694 = FunctionTemplate->getTemplateParameters(); 5695 Deduced.clear(); 5696 Deduced.resize(TemplateParams->size()); 5697 5698 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 5699 for (unsigned I = 0, N = Function->getNumParams(); I != N; ++I) 5700 ::MarkUsedTemplateParameters(Ctx, Function->getParamDecl(I)->getType(), 5701 true, TemplateParams->getDepth(), Deduced); 5702} 5703 5704bool hasDeducibleTemplateParameters(Sema &S, 5705 FunctionTemplateDecl *FunctionTemplate, 5706 QualType T) { 5707 if (!T->isDependentType()) 5708 return false; 5709 5710 TemplateParameterList *TemplateParams 5711 = FunctionTemplate->getTemplateParameters(); 5712 llvm::SmallBitVector Deduced(TemplateParams->size()); 5713 ::MarkUsedTemplateParameters(S.Context, T, true, TemplateParams->getDepth(), 5714 Deduced); 5715 5716 return Deduced.any(); 5717}

←

/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/include/clang/AST/Type.h

→

1	//===- Type.h - C Language Family Type Representation ------------ C++ --===//
2	//
3	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4	// See https://llvm.org/LICENSE.txt for license information.
5	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6	//
7	//===----------------------------------------------------------------------===//
8	//
9	/// \file
10	/// C Language Family Type Representation
11	///
12	/// This file defines the clang::Type interface and subclasses, used to
13	/// represent types for languages in the C family.
14	//
15	//===----------------------------------------------------------------------===//
16
17	#ifndef LLVM_CLANG_AST_TYPE_H
18	#define LLVM_CLANG_AST_TYPE_H
19
20	#include "clang/AST/NestedNameSpecifier.h"
21	#include "clang/AST/TemplateName.h"
22	#include "clang/Basic/AddressSpaces.h"
23	#include "clang/Basic/AttrKinds.h"
24	#include "clang/Basic/Diagnostic.h"
25	#include "clang/Basic/ExceptionSpecificationType.h"
26	#include "clang/Basic/LLVM.h"
27	#include "clang/Basic/Linkage.h"
28	#include "clang/Basic/PartialDiagnostic.h"
29	#include "clang/Basic/SourceLocation.h"
30	#include "clang/Basic/Specifiers.h"
31	#include "clang/Basic/Visibility.h"
32	#include "llvm/ADT/APInt.h"
33	#include "llvm/ADT/APSInt.h"
34	#include "llvm/ADT/ArrayRef.h"
35	#include "llvm/ADT/FoldingSet.h"
36	#include "llvm/ADT/None.h"
37	#include "llvm/ADT/Optional.h"
38	#include "llvm/ADT/PointerIntPair.h"
39	#include "llvm/ADT/PointerUnion.h"
40	#include "llvm/ADT/StringRef.h"
41	#include "llvm/ADT/Twine.h"
42	#include "llvm/ADT/iterator_range.h"
43	#include "llvm/Support/Casting.h"
44	#include "llvm/Support/Compiler.h"
45	#include "llvm/Support/ErrorHandling.h"
46	#include "llvm/Support/PointerLikeTypeTraits.h"
47	#include "llvm/Support/type_traits.h"
48	#include "llvm/Support/TrailingObjects.h"
49	#include <cassert>
50	#include <cstddef>
51	#include <cstdint>
52	#include <cstring>
53	#include <string>
54	#include <type_traits>
55	#include <utility>
56
57	namespace clang {
58
59	class ExtQuals;
60	class QualType;
61	class TagDecl;
62	class Type;
63
64	enum {
65	TypeAlignmentInBits = 4,
66	TypeAlignment = 1 << TypeAlignmentInBits
67	};
68
69	} // namespace clang
70
71	namespace llvm {
72
73	template <typename T>
74	struct PointerLikeTypeTraits;
75	template<>
76	struct PointerLikeTypeTraits< ::clang::Type*> {
77	static inline void getAsVoidPointer(::clang::Type P) { return P; }
78
79	static inline ::clang::Type getFromVoidPointer(void P) {
80	return static_cast< ::clang::Type*>(P);
81	}
82
83	enum { NumLowBitsAvailable = clang::TypeAlignmentInBits };
84	};
85
86	template<>
87	struct PointerLikeTypeTraits< ::clang::ExtQuals*> {
88	static inline void getAsVoidPointer(::clang::ExtQuals P) { return P; }
89
90	static inline ::clang::ExtQuals getFromVoidPointer(void P) {
91	return static_cast< ::clang::ExtQuals*>(P);
92	}
93
94	enum { NumLowBitsAvailable = clang::TypeAlignmentInBits };
95	};
96
97	} // namespace llvm
98
99	namespace clang {
100
101	class ASTContext;
102	template <typename> class CanQual;
103	class CXXRecordDecl;
104	class DeclContext;
105	class EnumDecl;
106	class Expr;
107	class ExtQualsTypeCommonBase;
108	class FunctionDecl;
109	class IdentifierInfo;
110	class NamedDecl;
111	class ObjCInterfaceDecl;
112	class ObjCProtocolDecl;
113	class ObjCTypeParamDecl;
114	struct PrintingPolicy;
115	class RecordDecl;
116	class Stmt;
117	class TagDecl;
118	class TemplateArgument;
119	class TemplateArgumentListInfo;
120	class TemplateArgumentLoc;
121	class TemplateTypeParmDecl;
122	class TypedefNameDecl;
123	class UnresolvedUsingTypenameDecl;
124
125	using CanQualType = CanQual<Type>;
126
127	// Provide forward declarations for all of the *Type classes.
128	#define TYPE(Class, Base) class Class##Type;
129	#include "clang/AST/TypeNodes.inc"
130
131	/// The collection of all-type qualifiers we support.
132	/// Clang supports five independent qualifiers:
133	/// * C99: const, volatile, and restrict
134	/// * MS: __unaligned
135	/// * Embedded C (TR18037): address spaces
136	/// * Objective C: the GC attributes (none, weak, or strong)
137	class Qualifiers {
138	public:
139	enum TQ { // NOTE: These flags must be kept in sync with DeclSpec::TQ.
140	Const = 0x1,
141	Restrict = 0x2,
142	Volatile = 0x4,
143	CVRMask = Const \| Volatile \| Restrict
144	};
145
146	enum GC {
147	GCNone = 0,
148	Weak,
149	Strong
150	};
151
152	enum ObjCLifetime {
153	/// There is no lifetime qualification on this type.
154	OCL_None,
155
156	/// This object can be modified without requiring retains or
157	/// releases.
158	OCL_ExplicitNone,
159
160	/// Assigning into this object requires the old value to be
161	/// released and the new value to be retained. The timing of the
162	/// release of the old value is inexact: it may be moved to
163	/// immediately after the last known point where the value is
164	/// live.
165	OCL_Strong,
166
167	/// Reading or writing from this object requires a barrier call.
168	OCL_Weak,
169
170	/// Assigning into this object requires a lifetime extension.
171	OCL_Autoreleasing
172	};
173
174	enum {
175	/// The maximum supported address space number.
176	/// 23 bits should be enough for anyone.
177	MaxAddressSpace = 0x7fffffu,
178
179	/// The width of the "fast" qualifier mask.
180	FastWidth = 3,
181
182	/// The fast qualifier mask.
183	FastMask = (1 << FastWidth) - 1
184	};
185
186	/// Returns the common set of qualifiers while removing them from
187	/// the given sets.
188	static Qualifiers removeCommonQualifiers(Qualifiers &L, Qualifiers &R) {
189	// If both are only CVR-qualified, bit operations are sufficient.
190	if (!(L.Mask & ~CVRMask) && !(R.Mask & ~CVRMask)) {
191	Qualifiers Q;
192	Q.Mask = L.Mask & R.Mask;
193	L.Mask &= ~Q.Mask;