/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp

Bug Summary

File:	clang/lib/Analysis/CalledOnceCheck.cpp
Warning:	line 988, column 12 Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name CalledOnceCheck.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 -fhalf-no-semantic-interposition -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/build-llvm/tools/clang/lib/Analysis -resource-dir /usr/lib/llvm-13/lib/clang/13.0.0 -D CLANG_ROUND_TRIP_CC1_ARGS=ON -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/build-llvm/tools/clang/lib/Analysis -I /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis -I /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include -I /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/build-llvm/include -I /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/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/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../x86_64-linux-gnu/include -internal-isystem /usr/lib/llvm-13/lib/clang/13.0.0/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-13~++20210405022414+5f57793c4fe4/build-llvm/tools/clang/lib/Analysis -fdebug-prefix-map=/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-04-05-202135-9119-1 -x c++ /build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp

/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp

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1//===- CalledOnceCheck.cpp - Check 'called once' parameters ---------------===//
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//===----------------------------------------------------------------------===//

9#include "clang/Analysis/Analyses/CalledOnceCheck.h"
10#include "clang/AST/ASTContext.h"
11#include "clang/AST/Attr.h"
12#include "clang/AST/Decl.h"
13#include "clang/AST/DeclBase.h"
14#include "clang/AST/Expr.h"
15#include "clang/AST/ExprObjC.h"
16#include "clang/AST/OperationKinds.h"
17#include "clang/AST/ParentMap.h"
18#include "clang/AST/RecursiveASTVisitor.h"
19#include "clang/AST/Stmt.h"
20#include "clang/AST/StmtObjC.h"
21#include "clang/AST/StmtVisitor.h"
22#include "clang/AST/Type.h"
23#include "clang/Analysis/AnalysisDeclContext.h"
24#include "clang/Analysis/CFG.h"
25#include "clang/Analysis/FlowSensitive/DataflowWorklist.h"
26#include "clang/Basic/Builtins.h"
27#include "clang/Basic/IdentifierTable.h"
28#include "clang/Basic/LLVM.h"
29#include "llvm/ADT/BitVector.h"
30#include "llvm/ADT/BitmaskEnum.h"
31#include "llvm/ADT/Optional.h"
32#include "llvm/ADT/PointerIntPair.h"
33#include "llvm/ADT/STLExtras.h"
34#include "llvm/ADT/Sequence.h"
35#include "llvm/ADT/SmallVector.h"
36#include "llvm/ADT/StringRef.h"
37#include "llvm/Support/Casting.h"
38#include "llvm/Support/Compiler.h"
39#include "llvm/Support/ErrorHandling.h"
40#include <memory>

42using namespace clang;

44namespace {
45static constexpr unsigned EXPECTED_MAX_NUMBER_OF_PARAMS = 2;
46template <class T>
47using ParamSizedVector = llvm::SmallVector<T, EXPECTED_MAX_NUMBER_OF_PARAMS>;
48static constexpr unsigned EXPECTED_NUMBER_OF_BASIC_BLOCKS = 8;
49template <class T>
50using CFGSizedVector = llvm::SmallVector<T, EXPECTED_NUMBER_OF_BASIC_BLOCKS>;
51constexpr llvm::StringLiteral CONVENTIONAL_NAMES[] = {
  "completionHandler", "completion",      "withCompletionHandler",
  "withCompletion",    "completionBlock", "withCompletionBlock",
  "replyTo",           "reply",           "withReplyTo"};
55constexpr llvm::StringLiteral CONVENTIONAL_SUFFIXES[] = {
  "WithCompletionHandler", "WithCompletion", "WithCompletionBlock",
  "WithReplyTo", "WithReply"};
58constexpr llvm::StringLiteral CONVENTIONAL_CONDITIONS[] = {
  "error", "cancel", "shouldCall", "done", "OK", "success"};

61struct KnownCalledOnceParameter {
llvm::StringLiteral FunctionName;
unsigned ParamIndex;
64};
65constexpr KnownCalledOnceParameter KNOWN_CALLED_ONCE_PARAMETERS[] = {
  {llvm::StringLiteral{"dispatch_async"}, 1},
  {llvm::StringLiteral{"dispatch_async_and_wait"}, 1},
  {llvm::StringLiteral{"dispatch_after"}, 2},
  {llvm::StringLiteral{"dispatch_sync"}, 1},
  {llvm::StringLiteral{"dispatch_once"}, 1},
  {llvm::StringLiteral{"dispatch_barrier_async"}, 1},
  {llvm::StringLiteral{"dispatch_barrier_async_and_wait"}, 1},
  {llvm::StringLiteral{"dispatch_barrier_sync"}, 1}};

75class ParameterStatus {
76public:
// Status kind is basically the main part of parameter's status.
// The kind represents our knowledge (so far) about a tracked parameter
// in the context of this analysis.
//
// Since we want to report on missing and extraneous calls, we need to
// track the fact whether paramater was called or not.  This automatically
// decides two kinds: `NotCalled` and `Called`.
//
// One of the erroneous situations is the case when parameter is called only
// on some of the paths.  We could've considered it `NotCalled`, but we want
// to report double call warnings even if these two calls are not guaranteed
// to happen in every execution.  We also don't want to have it as `Called`
// because not calling tracked parameter on all of the paths is an error
// on its own.  For these reasons, we need to have a separate kind,
// `MaybeCalled`, and change `Called` to `DefinitelyCalled` to avoid
// confusion.
//
// Two violations of calling parameter more than once and not calling it on
// every path are not, however, mutually exclusive.  In situations where both
// violations take place, we prefer to report ONLY double call.  It's always
// harder to pinpoint a bug that has arisen when a user neglects to take the
// right action (and therefore, no action is taken), than when a user takes
// the wrong action.  And, in order to remember that we already reported
// a double call, we need another kind: `Reported`.
//
// Our analysis is intra-procedural and, while in the perfect world,
// developers only use tracked parameters to call them, in the real world,
// the picture might be different.  Parameters can be stored in global
// variables or leaked into other functions that we know nothing about.
// We try to be lenient and trust users.  Another kind `Escaped` reflects
// such situations.  We don't know if it gets called there or not, but we
// should always think of `Escaped` as the best possible option.
//
// Some of the paths in the analyzed functions might end with a call
// to noreturn functions.  Such paths are not required to have parameter
// calls and we want to track that.  For the purposes of better diagnostics,
// we don't want to reuse `Escaped` and, thus, have another kind `NoReturn`.
//
// Additionally, we have `NotVisited` kind that tells us nothing about
// a tracked parameter, but is used for tracking analyzed (aka visited)
// basic blocks.
//
// If we consider `|` to be a JOIN operation of two kinds coming from
// two different paths, the following properties must hold:
//
//   1. for any Kind K: K | K == K
//      Joining two identical kinds should result in the same kind.
//
//   2. for any Kind K: Reported | K == Reported
//      Doesn't matter on which path it was reported, it still is.
//
//   3. for any Kind K: NoReturn | K == K
//      We can totally ignore noreturn paths during merges.
//
//   4. DefinitelyCalled | NotCalled == MaybeCalled
//      Called on one path, not called on another - that's simply
//      a definition for MaybeCalled.
//
//   5. for any Kind K in [DefinitelyCalled, NotCalled, MaybeCalled]:
//      Escaped | K == K
//      Escaped mirrors other statuses after joins.
//      Every situation, when we join any of the listed kinds K,
//      is a violation.  For this reason, in order to assume the
//      best outcome for this escape, we consider it to be the
//      same as the other path.
//
//   6. for any Kind K in [DefinitelyCalled, NotCalled]:
//      MaybeCalled | K == MaybeCalled
//      MaybeCalled should basically stay after almost every join.
enum Kind {
  // No-return paths should be absolutely transparent for the analysis.
  // 0x0 is the identity element for selected join operation (binary or).
  NoReturn = 0x0, /* 0000 */
  // Escaped marks situations when marked parameter escaped into
  // another function (so we can assume that it was possibly called there).
  Escaped = 0x1, /* 0001 */
  // Parameter was definitely called once at this point.
  DefinitelyCalled = 0x3, /* 0011 */
  // Kinds less or equal to NON_ERROR_STATUS are not considered errors.
  NON_ERROR_STATUS = DefinitelyCalled,
  // Parameter was not yet called.
  NotCalled = 0x5, /* 0101 */
  // Parameter was not called at least on one path leading to this point,
  // while there is also at least one path that it gets called.
  MaybeCalled = 0x7, /* 0111 */
  // Parameter was not yet analyzed.
  NotVisited = 0x8, /* 1000 */
  // We already reported a violation and stopped tracking calls for this
  // parameter.
  Reported = 0x15, /* 1111 */
  LLVM_MARK_AS_BITMASK_ENUM(/* LargestValue = */ Reported)LLVM_BITMASK_LARGEST_ENUMERATOR = Reported
};

constexpr ParameterStatus() = default;
/* implicit */ ParameterStatus(Kind K) : StatusKind(K) {
  assert(!seenAnyCalls(K) && "Can't initialize status without a call")((!seenAnyCalls(K) && "Can't initialize status without a call"
) ? static_cast<void> (0) : __assert_fail ("!seenAnyCalls(K) && \"Can't initialize status without a call\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 172, __PRETTY_FUNCTION__));
}
ParameterStatus(Kind K, const Expr *Call) : StatusKind(K), Call(Call) {
  assert(seenAnyCalls(K) && "This kind is not supposed to have a call")((seenAnyCalls(K) && "This kind is not supposed to have a call"
) ? static_cast<void> (0) : __assert_fail ("seenAnyCalls(K) && \"This kind is not supposed to have a call\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 175, __PRETTY_FUNCTION__));
}

const Expr &getCall() const {
  assert(seenAnyCalls(getKind()) && "ParameterStatus doesn't have a call")((seenAnyCalls(getKind()) && "ParameterStatus doesn't have a call"
) ? static_cast<void> (0) : __assert_fail ("seenAnyCalls(getKind()) && \"ParameterStatus doesn't have a call\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 179, __PRETTY_FUNCTION__));
  return *Call;
}
static bool seenAnyCalls(Kind K) {
  return (K & DefinitelyCalled) == DefinitelyCalled && K != Reported;
}
bool seenAnyCalls() const { return seenAnyCalls(getKind()); }

static bool isErrorStatus(Kind K) { return K > NON_ERROR_STATUS; }
bool isErrorStatus() const { return isErrorStatus(getKind()); }

Kind getKind() const { return StatusKind; }

void join(const ParameterStatus &Other) {
  // If we have a pointer already, let's keep it.
  // For the purposes of the analysis, it doesn't really matter
  // which call we report.
  //
  // If we don't have a pointer, let's take whatever gets joined.
  if (!Call) {
    Call = Other.Call;
  }
  // Join kinds.
  StatusKind |= Other.getKind();
}

bool operator==(const ParameterStatus &Other) const {
  // We compare only kinds, pointers on their own is only additional
  // information.
  return getKind() == Other.getKind();
}

211private:
// It would've been a perfect place to use llvm::PointerIntPair, but
// unfortunately NumLowBitsAvailable for clang::Expr had been reduced to 2.
Kind StatusKind = NotVisited;
const Expr *Call = nullptr;
216};

218/// State aggregates statuses of all tracked parameters.
219class State {
220public:
State(unsigned Size, ParameterStatus::Kind K = ParameterStatus::NotVisited)
    : ParamData(Size, K) {}

/// Return status of a parameter with the given index.
/// \{
ParameterStatus &getStatusFor(unsigned Index) { return ParamData[Index]; }
const ParameterStatus &getStatusFor(unsigned Index) const {
  return ParamData[Index];
}
/// \}

/// Return true if parameter with the given index can be called.
bool seenAnyCalls(unsigned Index) const {
  return getStatusFor(Index).seenAnyCalls();
}
/// Return a reference that we consider a call.
///
/// Should only be used for parameters that can be called.
const Expr &getCallFor(unsigned Index) const {
  return getStatusFor(Index).getCall();
}
/// Return status kind of parameter with the given index.
ParameterStatus::Kind getKindFor(unsigned Index) const {
  return getStatusFor(Index).getKind();
}

bool isVisited() const {
  return llvm::all_of(ParamData, [](const ParameterStatus &S) {
    return S.getKind() != ParameterStatus::NotVisited;
  });
}

// Join other state into the current state.
void join(const State &Other) {
  assert(ParamData.size() == Other.ParamData.size() &&((ParamData.size() == Other.ParamData.size() && "Couldn't join statuses with different sizes"
) ? static_cast<void> (0) : __assert_fail ("ParamData.size() == Other.ParamData.size() && \"Couldn't join statuses with different sizes\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 256, __PRETTY_FUNCTION__))
         "Couldn't join statuses with different sizes")((ParamData.size() == Other.ParamData.size() && "Couldn't join statuses with different sizes"
) ? static_cast<void> (0) : __assert_fail ("ParamData.size() == Other.ParamData.size() && \"Couldn't join statuses with different sizes\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 256, __PRETTY_FUNCTION__));
  for (auto Pair : llvm::zip(ParamData, Other.ParamData)) {
    std::get<0>(Pair).join(std::get<1>(Pair));
  }
}

using iterator = ParamSizedVector<ParameterStatus>::iterator;
using const_iterator = ParamSizedVector<ParameterStatus>::const_iterator;

iterator begin() { return ParamData.begin(); }
iterator end() { return ParamData.end(); }

const_iterator begin() const { return ParamData.begin(); }
const_iterator end() const { return ParamData.end(); }

bool operator==(const State &Other) const {
  return ParamData == Other.ParamData;
}

275private:
ParamSizedVector<ParameterStatus> ParamData;
277};

279/// A simple class that finds DeclRefExpr in the given expression.
280///
281/// However, we don't want to find ANY nested DeclRefExpr skipping whatever
282/// expressions on our way.  Only certain expressions considered "no-op"
283/// for our task are indeed skipped.
284class DeclRefFinder
  : public ConstStmtVisitor<DeclRefFinder, const DeclRefExpr *> {
286public:
/// Find a DeclRefExpr in the given expression.
///
/// In its most basic form (ShouldRetrieveFromComparisons == false),
/// this function can be simply reduced to the following question:
///
///   - If expression E is used as a function argument, could we say
///     that DeclRefExpr nested in E is used as an argument?
///
/// According to this rule, we can say that parens, casts and dereferencing
/// (dereferencing only applied to function pointers, but this is our case)
/// can be skipped.
///
/// When we should look into comparisons the question changes to:
///
///   - If expression E is used as a condition, could we say that
///     DeclRefExpr is being checked?
///
/// And even though, these are two different questions, they have quite a lot
/// in common.  Actually, we can say that whatever expression answers
/// positively the first question also fits the second question as well.
///
/// In addition, we skip binary operators == and !=, and unary opeartor !.
static const DeclRefExpr *find(const Expr *E,
                               bool ShouldRetrieveFromComparisons = false) {
  return DeclRefFinder(ShouldRetrieveFromComparisons).Visit(E);
}

const DeclRefExpr *VisitDeclRefExpr(const DeclRefExpr *DR) { return DR; }

const DeclRefExpr *VisitUnaryOperator(const UnaryOperator *UO) {
  switch (UO->getOpcode()) {
  case UO_LNot:
    // We care about logical not only if we care about comparisons.
    if (!ShouldRetrieveFromComparisons)
      return nullptr;
    LLVM_FALLTHROUGH[[gnu::fallthrough]];
  // Function pointer/references can be dereferenced before a call.
  // That doesn't make it, however, any different from a regular call.
  // For this reason, dereference operation is a "no-op".
  case UO_Deref:
    return Visit(UO->getSubExpr());
  default:
    return nullptr;
  }
}

const DeclRefExpr *VisitBinaryOperator(const BinaryOperator *BO) {
  if (!ShouldRetrieveFromComparisons)
    return nullptr;

  switch (BO->getOpcode()) {
  case BO_EQ:
  case BO_NE: {
    const DeclRefExpr *LHS = Visit(BO->getLHS());
    return LHS ? LHS : Visit(BO->getRHS());
  }
  default:
    return nullptr;
  }
}

const DeclRefExpr *VisitOpaqueValueExpr(const OpaqueValueExpr *OVE) {
  return Visit(OVE->getSourceExpr());
}

const DeclRefExpr *VisitCallExpr(const CallExpr *CE) {
  if (!ShouldRetrieveFromComparisons)
    return nullptr;

  // We want to see through some of the boolean builtin functions
  // that we are likely to see in conditions.
  switch (CE->getBuiltinCallee()) {
  case Builtin::BI__builtin_expect:
  case Builtin::BI__builtin_expect_with_probability: {
    assert(CE->getNumArgs() >= 2)((CE->getNumArgs() >= 2) ? static_cast<void> (0) :
 __assert_fail ("CE->getNumArgs() >= 2", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 361, __PRETTY_FUNCTION__));

    const DeclRefExpr *Candidate = Visit(CE->getArg(0));
    return Candidate != nullptr ? Candidate : Visit(CE->getArg(1));
  }

  case Builtin::BI__builtin_unpredictable:
    return Visit(CE->getArg(0));

  default:
    return nullptr;
  }
}

const DeclRefExpr *VisitExpr(const Expr *E) {
  // It is a fallback method that gets called whenever the actual type
  // of the given expression is not covered.
  //
  // We first check if we have anything to skip.  And then repeat the whole
  // procedure for a nested expression instead.
  const Expr *DeclutteredExpr = E->IgnoreParenCasts();
  return E != DeclutteredExpr ? Visit(DeclutteredExpr) : nullptr;
}

385private:
DeclRefFinder(bool ShouldRetrieveFromComparisons)
    : ShouldRetrieveFromComparisons(ShouldRetrieveFromComparisons) {}

bool ShouldRetrieveFromComparisons;
390};

392const DeclRefExpr *findDeclRefExpr(const Expr *In,
                                 bool ShouldRetrieveFromComparisons = false) {
return DeclRefFinder::find(In, ShouldRetrieveFromComparisons);
395}

397const ParmVarDecl *
398findReferencedParmVarDecl(const Expr *In,
                        bool ShouldRetrieveFromComparisons = false) {
if (const DeclRefExpr *DR =
        findDeclRefExpr(In, ShouldRetrieveFromComparisons)) {
  return dyn_cast<ParmVarDecl>(DR->getDecl());
}

return nullptr;
406}

408/// Return conditions expression of a statement if it has one.
409const Expr *getCondition(const Stmt *S) {
if (!S) {
  return nullptr;
}

if (const auto *If = dyn_cast<IfStmt>(S)) {
  return If->getCond();
}
if (const auto *Ternary = dyn_cast<AbstractConditionalOperator>(S)) {
  return Ternary->getCond();
}

return nullptr;
422}

424/// A small helper class that collects all named identifiers in the given
425/// expression.  It traverses it recursively, so names from deeper levels
426/// of the AST will end up in the results.
427/// Results might have duplicate names, if this is a problem, convert to
428/// string sets afterwards.
429class NamesCollector : public RecursiveASTVisitor<NamesCollector> {
430public:
static constexpr unsigned EXPECTED_NUMBER_OF_NAMES = 5;
using NameCollection =
    llvm::SmallVector<llvm::StringRef, EXPECTED_NUMBER_OF_NAMES>;

static NameCollection collect(const Expr *From) {
  NamesCollector Impl;
  Impl.TraverseStmt(const_cast<Expr *>(From));
  return Impl.Result;
}

bool VisitDeclRefExpr(const DeclRefExpr *E) {
  Result.push_back(E->getDecl()->getName());
  return true;
}

bool VisitObjCPropertyRefExpr(const ObjCPropertyRefExpr *E) {
  llvm::StringRef Name;

  if (E->isImplicitProperty()) {
    ObjCMethodDecl *PropertyMethodDecl = nullptr;
    if (E->isMessagingGetter()) {
      PropertyMethodDecl = E->getImplicitPropertyGetter();
    } else {
      PropertyMethodDecl = E->getImplicitPropertySetter();
    }
    assert(PropertyMethodDecl &&((PropertyMethodDecl && "Implicit property must have associated declaration"
) ? static_cast<void> (0) : __assert_fail ("PropertyMethodDecl && \"Implicit property must have associated declaration\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 457, __PRETTY_FUNCTION__))
           "Implicit property must have associated declaration")((PropertyMethodDecl && "Implicit property must have associated declaration"
) ? static_cast<void> (0) : __assert_fail ("PropertyMethodDecl && \"Implicit property must have associated declaration\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 457, __PRETTY_FUNCTION__));
    Name = PropertyMethodDecl->getSelector().getNameForSlot(0);
  } else {
    assert(E->isExplicitProperty())((E->isExplicitProperty()) ? static_cast<void> (0) :
 __assert_fail ("E->isExplicitProperty()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 460, __PRETTY_FUNCTION__));
    Name = E->getExplicitProperty()->getName();
  }

  Result.push_back(Name);
  return true;
}

468private:
NamesCollector() = default;
NameCollection Result;
471};

473/// Check whether the given expression mentions any of conventional names.
474bool mentionsAnyOfConventionalNames(const Expr *E) {
NamesCollector::NameCollection MentionedNames = NamesCollector::collect(E);

return llvm::any_of(MentionedNames, [](llvm::StringRef ConditionName) {
  return llvm::any_of(
      CONVENTIONAL_CONDITIONS,
      [ConditionName](const llvm::StringLiteral &Conventional) {
        return ConditionName.contains_lower(Conventional);
      });
});
484}

486/// Clarification is a simple pair of a reason why parameter is not called
487/// on every path and a statement to blame.
488struct Clarification {
NeverCalledReason Reason;
const Stmt *Location;
491};

493/// A helper class that can produce a clarification based on the given pair
494/// of basic blocks.
495class NotCalledClarifier
  : public ConstStmtVisitor<NotCalledClarifier,
                            llvm::Optional<Clarification>> {
498public:
/// The main entrypoint for the class, the function that tries to find the
/// clarification of how to explain which sub-path starts with a CFG edge
/// from Conditional to SuccWithoutCall.
///
/// This means that this function has one precondition:
///   SuccWithoutCall should be a successor block for Conditional.
///
/// Because clarification is not needed for non-trivial pairs of blocks
/// (i.e. SuccWithoutCall is not the only successor), it returns meaningful
/// results only for such cases.  For this very reason, the parent basic
/// block, Conditional, is named that way, so it is clear what kind of
/// block is expected.
static llvm::Optional<Clarification>
clarify(const CFGBlock *Conditional, const CFGBlock *SuccWithoutCall) {
  if (const Stmt *Terminator = Conditional->getTerminatorStmt()) {
    return NotCalledClarifier{Conditional, SuccWithoutCall}.Visit(Terminator);
  }
  return llvm::None;
}

llvm::Optional<Clarification> VisitIfStmt(const IfStmt *If) {
  return VisitBranchingBlock(If, NeverCalledReason::IfThen);
}

llvm::Optional<Clarification>
VisitAbstractConditionalOperator(const AbstractConditionalOperator *Ternary) {
  return VisitBranchingBlock(Ternary, NeverCalledReason::IfThen);
}

llvm::Optional<Clarification> VisitSwitchStmt(const SwitchStmt *Switch) {
  const Stmt *CaseToBlame = SuccInQuestion->getLabel();
  if (!CaseToBlame) {
    // If interesting basic block is not labeled, it means that this
    // basic block does not represent any of the cases.
    return Clarification{NeverCalledReason::SwitchSkipped, Switch};
  }

  for (const SwitchCase *Case = Switch->getSwitchCaseList(); Case;
       Case = Case->getNextSwitchCase()) {
    if (Case == CaseToBlame) {
      return Clarification{NeverCalledReason::Switch, Case};
    }
  }

  llvm_unreachable("Found unexpected switch structure")::llvm::llvm_unreachable_internal("Found unexpected switch structure"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 543);
}

llvm::Optional<Clarification> VisitForStmt(const ForStmt *For) {
  return VisitBranchingBlock(For, NeverCalledReason::LoopEntered);
}

llvm::Optional<Clarification> VisitWhileStmt(const WhileStmt *While) {
  return VisitBranchingBlock(While, NeverCalledReason::LoopEntered);
}

llvm::Optional<Clarification>
VisitBranchingBlock(const Stmt *Terminator, NeverCalledReason DefaultReason) {
  assert(Parent->succ_size() == 2 &&((Parent->succ_size() == 2 && "Branching block should have exactly two successors"
) ? static_cast<void> (0) : __assert_fail ("Parent->succ_size() == 2 && \"Branching block should have exactly two successors\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 557, __PRETTY_FUNCTION__))
         "Branching block should have exactly two successors")((Parent->succ_size() == 2 && "Branching block should have exactly two successors"
) ? static_cast<void> (0) : __assert_fail ("Parent->succ_size() == 2 && \"Branching block should have exactly two successors\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 557, __PRETTY_FUNCTION__));
  unsigned SuccessorIndex = getSuccessorIndex(Parent, SuccInQuestion);
  NeverCalledReason ActualReason =
      updateForSuccessor(DefaultReason, SuccessorIndex);
  return Clarification{ActualReason, Terminator};
}

llvm::Optional<Clarification> VisitBinaryOperator(const BinaryOperator *) {
  // We don't want to report on short-curcuit logical operations.
  return llvm::None;
}

llvm::Optional<Clarification> VisitStmt(const Stmt *Terminator) {
  // If we got here, we didn't have a visit function for more derived
  // classes of statement that this terminator actually belongs to.
  //
  // This is not a good scenario and should not happen in practice, but
  // at least we'll warn the user.
  return Clarification{NeverCalledReason::FallbackReason, Terminator};
}

static unsigned getSuccessorIndex(const CFGBlock *Parent,
                                  const CFGBlock *Child) {
  CFGBlock::const_succ_iterator It = llvm::find(Parent->succs(), Child);
  assert(It != Parent->succ_end() &&((It != Parent->succ_end() && "Given blocks should be in parent-child relationship"
) ? static_cast<void> (0) : __assert_fail ("It != Parent->succ_end() && \"Given blocks should be in parent-child relationship\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 582, __PRETTY_FUNCTION__))
         "Given blocks should be in parent-child relationship")((It != Parent->succ_end() && "Given blocks should be in parent-child relationship"
) ? static_cast<void> (0) : __assert_fail ("It != Parent->succ_end() && \"Given blocks should be in parent-child relationship\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 582, __PRETTY_FUNCTION__));
  return It - Parent->succ_begin();
}

static NeverCalledReason
updateForSuccessor(NeverCalledReason ReasonForTrueBranch,
                   unsigned SuccessorIndex) {
  assert(SuccessorIndex <= 1)((SuccessorIndex <= 1) ? static_cast<void> (0) : __assert_fail
 ("SuccessorIndex <= 1", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 589, __PRETTY_FUNCTION__));
  unsigned RawReason =
      static_cast<unsigned>(ReasonForTrueBranch) + SuccessorIndex;
  assert(RawReason <=((RawReason <= static_cast<unsigned>(NeverCalledReason
::LARGEST_VALUE)) ? static_cast<void> (0) : __assert_fail
 ("RawReason <= static_cast<unsigned>(NeverCalledReason::LARGEST_VALUE)"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 593, __PRETTY_FUNCTION__))
         static_cast<unsigned>(NeverCalledReason::LARGEST_VALUE))((RawReason <= static_cast<unsigned>(NeverCalledReason
::LARGEST_VALUE)) ? static_cast<void> (0) : __assert_fail
 ("RawReason <= static_cast<unsigned>(NeverCalledReason::LARGEST_VALUE)"
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 593, __PRETTY_FUNCTION__));
  return static_cast<NeverCalledReason>(RawReason);
}

597private:
NotCalledClarifier(const CFGBlock *Parent, const CFGBlock *SuccInQuestion)
    : Parent(Parent), SuccInQuestion(SuccInQuestion) {}

const CFGBlock *Parent, *SuccInQuestion;
602};

604class CalledOnceChecker : public ConstStmtVisitor<CalledOnceChecker> {
605public:
static void check(AnalysisDeclContext &AC, CalledOnceCheckHandler &Handler,
                  bool CheckConventionalParameters) {
  CalledOnceChecker(AC, Handler, CheckConventionalParameters).check();
}

611private:
CalledOnceChecker(AnalysisDeclContext &AC, CalledOnceCheckHandler &Handler,
                  bool CheckConventionalParameters)
    : FunctionCFG(*AC.getCFG()), AC(AC), Handler(Handler),
      CheckConventionalParameters(CheckConventionalParameters),
      CurrentState(0) {
  initDataStructures();
  assert((size() == 0 || !States.empty()) &&(((size() == 0 || !States.empty()) && "Data structures are inconsistent"
) ? static_cast<void> (0) : __assert_fail ("(size() == 0 || !States.empty()) && \"Data structures are inconsistent\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 619, __PRETTY_FUNCTION__))
         "Data structures are inconsistent")(((size() == 0 || !States.empty()) && "Data structures are inconsistent"
) ? static_cast<void> (0) : __assert_fail ("(size() == 0 || !States.empty()) && \"Data structures are inconsistent\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 619, __PRETTY_FUNCTION__));
}

//===----------------------------------------------------------------------===//
//                            Initializing functions
//===----------------------------------------------------------------------===//

void initDataStructures() {
  const Decl *AnalyzedDecl = AC.getDecl();

  if (const auto *Function = dyn_cast<FunctionDecl>(AnalyzedDecl)) {
    findParamsToTrack(Function);
  } else if (const auto *Method = dyn_cast<ObjCMethodDecl>(AnalyzedDecl)) {
    findParamsToTrack(Method);
  } else if (const auto *Block = dyn_cast<BlockDecl>(AnalyzedDecl)) {
    findCapturesToTrack(Block);
    findParamsToTrack(Block);
  }

  // Have something to track, let's init states for every block from the CFG.
  if (size() != 0) {
    States =
        CFGSizedVector<State>(FunctionCFG.getNumBlockIDs(), State(size()));
  }
}

void findCapturesToTrack(const BlockDecl *Block) {
  for (const auto &Capture : Block->captures()) {
    if (const auto *P = dyn_cast<ParmVarDecl>(Capture.getVariable())) {
      // Parameter DeclContext is its owning function or method.
      const DeclContext *ParamContext = P->getDeclContext();
      if (shouldBeCalledOnce(ParamContext, P)) {
        TrackedParams.push_back(P);
      }
    }
  }
}

template <class FunctionLikeDecl>
void findParamsToTrack(const FunctionLikeDecl *Function) {
  for (unsigned Index : llvm::seq<unsigned>(0u, Function->param_size())) {
    if (shouldBeCalledOnce(Function, Index)) {
      TrackedParams.push_back(Function->getParamDecl(Index));
    }
  }
}

//===----------------------------------------------------------------------===//
//                         Main logic 'check' functions
//===----------------------------------------------------------------------===//

void check() {
  // Nothing to check here: we don't have marked parameters.
  if (size() == 0 || isPossiblyEmptyImpl())
    return;

  assert(((llvm::none_of(States, [](const State &S) { return S.isVisited
(); }) && "None of the blocks should be 'visited' before the analysis"
) ? static_cast<void> (0) : __assert_fail ("llvm::none_of(States, [](const State &S) { return S.isVisited(); }) && \"None of the blocks should be 'visited' before the analysis\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 677, __PRETTY_FUNCTION__))
      llvm::none_of(States, [](const State &S) { return S.isVisited(); }) &&((llvm::none_of(States, [](const State &S) { return S.isVisited
(); }) && "None of the blocks should be 'visited' before the analysis"
) ? static_cast<void> (0) : __assert_fail ("llvm::none_of(States, [](const State &S) { return S.isVisited(); }) && \"None of the blocks should be 'visited' before the analysis\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 677, __PRETTY_FUNCTION__))
      "None of the blocks should be 'visited' before the analysis")((llvm::none_of(States, [](const State &S) { return S.isVisited
(); }) && "None of the blocks should be 'visited' before the analysis"
) ? static_cast<void> (0) : __assert_fail ("llvm::none_of(States, [](const State &S) { return S.isVisited(); }) && \"None of the blocks should be 'visited' before the analysis\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 677, __PRETTY_FUNCTION__));

  // For our task, both backward and forward approaches suite well.
  // However, in order to report better diagnostics, we decided to go with
  // backward analysis.
  //
  // Let's consider the following CFG and how forward and backward analyses
  // will work for it.
  //
  //                  FORWARD:           |                 BACKWARD:
  //                    #1               |                     #1
  //                +---------+          |               +-----------+
  //                |   if    |          |               |MaybeCalled|
  //                +---------+          |               +-----------+
  //                |NotCalled|          |               |    if     |
  //                +---------+          |               +-----------+
  //                 /       \           |                 /       \
  //         #2     /         \  #3      |         #2     /         \  #3
  // +----------------+      +---------+ | +----------------+      +---------+
  // |     foo()      |      |   ...   | | |DefinitelyCalled|      |NotCalled|
  // +----------------+      +---------+ | +----------------+      +---------+
  // |DefinitelyCalled|      |NotCalled| | |     foo()      |      |   ...   |
  // +----------------+      +---------+ | +----------------+      +---------+
  //                \         /          |                \         /
  //                 \  #4   /           |                 \  #4   /
  //               +-----------+         |                +---------+
  //               |    ...    |         |                |NotCalled|
  //               +-----------+         |                +---------+
  //               |MaybeCalled|         |                |   ...   |
  //               +-----------+         |                +---------+
  //
  // The most natural way to report lacking call in the block #3 would be to
  // message that the false branch of the if statement in the block #1 doesn't
  // have a call.  And while with the forward approach we'll need to find a
  // least common ancestor or something like that to find the 'if' to blame,
  // backward analysis gives it to us out of the box.
  BackwardDataflowWorklist Worklist(FunctionCFG, AC);

  // Let's visit EXIT.
  const CFGBlock *Exit = &FunctionCFG.getExit();
  assignState(Exit, State(size(), ParameterStatus::NotCalled));
  Worklist.enqueuePredecessors(Exit);

  while (const CFGBlock *BB = Worklist.dequeue()) {
    assert(BB && "Worklist should filter out null blocks")((BB && "Worklist should filter out null blocks") ? static_cast
<void> (0) : __assert_fail ("BB && \"Worklist should filter out null blocks\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 721, __PRETTY_FUNCTION__));
    check(BB);
    assert(CurrentState.isVisited() &&((CurrentState.isVisited() && "After the check, basic block should be visited"
) ? static_cast<void> (0) : __assert_fail ("CurrentState.isVisited() && \"After the check, basic block should be visited\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 724, __PRETTY_FUNCTION__))
           "After the check, basic block should be visited")((CurrentState.isVisited() && "After the check, basic block should be visited"
) ? static_cast<void> (0) : __assert_fail ("CurrentState.isVisited() && \"After the check, basic block should be visited\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 724, __PRETTY_FUNCTION__));

    // Traverse successor basic blocks if the status of this block
    // has changed.
    if (assignState(BB, CurrentState)) {
      Worklist.enqueuePredecessors(BB);
    }
  }

  // Check that we have all tracked parameters at the last block.
  // As we are performing a backward version of the analysis,
  // it should be the ENTRY block.
  checkEntry(&FunctionCFG.getEntry());
}

void check(const CFGBlock *BB) {
  // We start with a state 'inherited' from all the successors.
  CurrentState = joinSuccessors(BB);
  assert(CurrentState.isVisited() &&((CurrentState.isVisited() && "Shouldn't start with a 'not visited' state"
) ? static_cast<void> (0) : __assert_fail ("CurrentState.isVisited() && \"Shouldn't start with a 'not visited' state\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 743, __PRETTY_FUNCTION__))
         "Shouldn't start with a 'not visited' state")((CurrentState.isVisited() && "Shouldn't start with a 'not visited' state"
) ? static_cast<void> (0) : __assert_fail ("CurrentState.isVisited() && \"Shouldn't start with a 'not visited' state\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 743, __PRETTY_FUNCTION__));

  // This is the 'exit' situation, broken promises are probably OK
  // in such scenarios.
  if (BB->hasNoReturnElement()) {
    markNoReturn();
    // This block still can have calls (even multiple calls) and
    // for this reason there is no early return here.
  }

  // We use a backward dataflow propagation and for this reason we
  // should traverse basic blocks bottom-up.
  for (const CFGElement &Element : llvm::reverse(*BB)) {
    if (Optional<CFGStmt> S = Element.getAs<CFGStmt>()) {
      check(S->getStmt());
    }
  }
}
void check(const Stmt *S) { Visit(S); }

void checkEntry(const CFGBlock *Entry) {
  // We finalize this algorithm with the ENTRY block because
  // we use a backward version of the analysis.  This is where
  // we can judge that some of the tracked parameters are not called on
  // every path from ENTRY to EXIT.

  const State &EntryStatus = getState(Entry);
  llvm::BitVector NotCalledOnEveryPath(size(), false);
  llvm::BitVector NotUsedOnEveryPath(size(), false);

  // Check if there are no calls of the marked parameter at all
  for (const auto &IndexedStatus : llvm::enumerate(EntryStatus)) {
    const ParmVarDecl *Parameter = getParameter(IndexedStatus.index());

    switch (IndexedStatus.value().getKind()) {
    case ParameterStatus::NotCalled:
      // If there were places where this parameter escapes (aka being used),
      // we can provide a more useful diagnostic by pointing at the exact
      // branches where it is not even mentioned.
      if (!hasEverEscaped(IndexedStatus.index())) {
        // This parameter is was not used at all, so we should report the
        // most generic version of the warning.
        if (isCaptured(Parameter)) {
          // We want to specify that it was captured by the block.
          Handler.handleCapturedNeverCalled(Parameter, AC.getDecl(),
                                            !isExplicitlyMarked(Parameter));
        } else {
          Handler.handleNeverCalled(Parameter,
                                    !isExplicitlyMarked(Parameter));
        }
      } else {
        // Mark it as 'interesting' to figure out which paths don't even
        // have escapes.
        NotUsedOnEveryPath[IndexedStatus.index()] = true;
      }

      break;
    case ParameterStatus::MaybeCalled:
      // If we have 'maybe called' at this point, we have an error
      // that there is at least one path where this parameter
      // is not called.
      //
      // However, reporting the warning with only that information can be
      // too vague for the users.  For this reason, we mark such parameters
      // as "interesting" for further analysis.
      NotCalledOnEveryPath[IndexedStatus.index()] = true;
      break;
    default:
      break;
    }
  }

  // Early exit if we don't have parameters for extra analysis...
  if (NotCalledOnEveryPath.none() && NotUsedOnEveryPath.none() &&
      // ... or if we've seen variables with cleanup functions.
      // We can't reason that we've seen every path in this case,
      // and thus abandon reporting any warnings that imply that.
      !FunctionHasCleanupVars)
    return;

  // We are looking for a pair of blocks A, B so that the following is true:
  //   * A is a predecessor of B
  //   * B is marked as NotCalled
  //   * A has at least one successor marked as either
  //     Escaped or DefinitelyCalled
  //
  // In that situation, it is guaranteed that B is the first block of the path
  // where the user doesn't call or use parameter in question.
  //
  // For this reason, branch A -> B can be used for reporting.
  //
  // This part of the algorithm is guarded by a condition that the function
  // does indeed have a violation of contract.  For this reason, we can
  // spend more time to find a good spot to place the warning.
  //
  // The following algorithm has the worst case complexity of O(V + E),
  // where V is the number of basic blocks in FunctionCFG,
  //       E is the number of edges between blocks in FunctionCFG.
  for (const CFGBlock *BB : FunctionCFG) {
    if (!BB)
      continue;

    const State &BlockState = getState(BB);

    for (unsigned Index : llvm::seq(0u, size())) {
      // We don't want to use 'isLosingCall' here because we want to report
      // the following situation as well:
      //
      //           MaybeCalled
      //            |  ...  |
      //    MaybeCalled   NotCalled
      //
      // Even though successor is not 'DefinitelyCalled', it is still useful
      // to report it, it is still a path without a call.
      if (NotCalledOnEveryPath[Index] &&
          BlockState.getKindFor(Index) == ParameterStatus::MaybeCalled) {

        findAndReportNotCalledBranches(BB, Index);
      } else if (NotUsedOnEveryPath[Index] &&
                 isLosingEscape(BlockState, BB, Index)) {

        findAndReportNotCalledBranches(BB, Index, /* IsEscape = */ true);
      }
    }
  }
}

/// Check potential call of a tracked parameter.
void checkDirectCall(const CallExpr *Call) {
  if (auto Index = getIndexOfCallee(Call)) {
    processCallFor(*Index, Call);
  }
}

/// Check the call expression for being an indirect call of one of the tracked
/// parameters.  It is indirect in the sense that this particular call is not
/// calling the parameter itself, but rather uses it as the argument.
template <class CallLikeExpr>
void checkIndirectCall(const CallLikeExpr *CallOrMessage) {
  // CallExpr::arguments does not interact nicely with llvm::enumerate.
  llvm::ArrayRef<const Expr *> Arguments = llvm::makeArrayRef(
      CallOrMessage->getArgs(), CallOrMessage->getNumArgs());

  // Let's check if any of the call arguments is a point of interest.
  for (const auto &Argument : llvm::enumerate(Arguments)) {
    if (auto Index = getIndexOfExpression(Argument.value())) {
2
←
Taking true branch→
4
←
Taking true branch→
      if (shouldBeCalledOnce(CallOrMessage, Argument.index())) {
3
←
Taking false branch→
5
←
Calling 'CalledOnceChecker::shouldBeCalledOnce'→
        // If the corresponding parameter is marked as 'called_once' we should
        // consider it as a call.
        processCallFor(*Index, CallOrMessage);
      } else {
        // Otherwise, we mark this parameter as escaped, which can be
        // interpreted both as called or not called depending on the context.
        processEscapeFor(*Index);
      }
      // Otherwise, let's keep the state as it is.
    }
  }
}

/// Process call of the parameter with the given index
void processCallFor(unsigned Index, const Expr *Call) {
  ParameterStatus &CurrentParamStatus = CurrentState.getStatusFor(Index);

  if (CurrentParamStatus.seenAnyCalls()) {

    // At this point, this parameter was called, so this is a second call.
    const ParmVarDecl *Parameter = getParameter(Index);
    Handler.handleDoubleCall(
        Parameter, &CurrentState.getCallFor(Index), Call,
        !isExplicitlyMarked(Parameter),
        // We are sure that the second call is definitely
        // going to happen if the status is 'DefinitelyCalled'.
        CurrentParamStatus.getKind() == ParameterStatus::DefinitelyCalled);

    // Mark this parameter as already reported on, so we don't repeat
    // warnings.
    CurrentParamStatus = ParameterStatus::Reported;

  } else if (CurrentParamStatus.getKind() != ParameterStatus::Reported) {
    // If we didn't report anything yet, let's mark this parameter
    // as called.
    ParameterStatus Called(ParameterStatus::DefinitelyCalled, Call);
    CurrentParamStatus = Called;
  }
}

/// Process escape of the parameter with the given index
void processEscapeFor(unsigned Index) {
  ParameterStatus &CurrentParamStatus = CurrentState.getStatusFor(Index);

  // Escape overrides whatever error we think happened.
  if (CurrentParamStatus.isErrorStatus()) {
    CurrentParamStatus = ParameterStatus::Escaped;
  }
}

void findAndReportNotCalledBranches(const CFGBlock *Parent, unsigned Index,
                                    bool IsEscape = false) {
  for (const CFGBlock *Succ : Parent->succs()) {
    if (!Succ)
      continue;

    if (getState(Succ).getKindFor(Index) == ParameterStatus::NotCalled) {
      assert(Parent->succ_size() >= 2 &&((Parent->succ_size() >= 2 && "Block should have at least two successors at this point"
) ? static_cast<void> (0) : __assert_fail ("Parent->succ_size() >= 2 && \"Block should have at least two successors at this point\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 948, __PRETTY_FUNCTION__))
             "Block should have at least two successors at this point")((Parent->succ_size() >= 2 && "Block should have at least two successors at this point"
) ? static_cast<void> (0) : __assert_fail ("Parent->succ_size() >= 2 && \"Block should have at least two successors at this point\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 948, __PRETTY_FUNCTION__));
      if (auto Clarification = NotCalledClarifier::clarify(Parent, Succ)) {
        const ParmVarDecl *Parameter = getParameter(Index);
        Handler.handleNeverCalled(
            Parameter, AC.getDecl(), Clarification->Location,
            Clarification->Reason, !IsEscape, !isExplicitlyMarked(Parameter));
      }
    }
  }
}

//===----------------------------------------------------------------------===//
//                   Predicate functions to check parameters
//===----------------------------------------------------------------------===//

/// Return true if parameter is explicitly marked as 'called_once'.
static bool isExplicitlyMarked(const ParmVarDecl *Parameter) {
  return Parameter->hasAttr<CalledOnceAttr>();
}

/// Return true if the given name matches conventional pattens.
static bool isConventional(llvm::StringRef Name) {
  return llvm::count(CONVENTIONAL_NAMES, Name) != 0;
}

/// Return true if the given name has conventional suffixes.
static bool hasConventionalSuffix(llvm::StringRef Name) {
  return llvm::any_of(CONVENTIONAL_SUFFIXES, [Name](llvm::StringRef Suffix) {
    return Name.endswith(Suffix);
  });
}

/// Return true if the given type can be used for conventional parameters.
static bool isConventional(QualType Ty) {
  if (!Ty->isBlockPointerType()) {
13
←
Calling 'Type::isBlockPointerType'→
16
←
Returning from 'Type::isBlockPointerType'→
17
←
Taking false branch→
    return false;
  }

  QualType BlockType = Ty->getAs<BlockPointerType>()->getPointeeType();
18
←
Assuming the object is a 'BlockPointerType'→
  // Completion handlers should have a block type with void return type.
  return BlockType->getAs<FunctionType>()->getReturnType()->isVoidType();
19
←
Assuming the object is not a 'FunctionType'→
20
←
Called C++ object pointer is null
}

/// Return true if the only parameter of the function is conventional.
static bool isOnlyParameterConventional(const FunctionDecl *Function) {
  IdentifierInfo *II = Function->getIdentifier();
  return Function->getNumParams() == 1 && II &&
         hasConventionalSuffix(II->getName());
}

/// Return true/false if 'swift_async' attribute states that the given
/// parameter is conventionally called once.
/// Return llvm::None if the given declaration doesn't have 'swift_async'
/// attribute.
static llvm::Optional<bool> isConventionalSwiftAsync(const Decl *D,
                                                     unsigned ParamIndex) {
  if (const SwiftAsyncAttr *A = D->getAttr<SwiftAsyncAttr>()) {
    if (A->getKind() == SwiftAsyncAttr::None) {
      return false;
    }

    return A->getCompletionHandlerIndex().getASTIndex() == ParamIndex;
  }
  return llvm::None;
}

/// Return true if the specified selector piece matches conventions.
static bool isConventionalSelectorPiece(Selector MethodSelector,
                                        unsigned PieceIndex,
                                        QualType PieceType) {
  if (!isConventional(PieceType)) {
    return false;
  }

  if (MethodSelector.getNumArgs() == 1) {
    assert(PieceIndex == 0)((PieceIndex == 0) ? static_cast<void> (0) : __assert_fail
 ("PieceIndex == 0", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 1023, __PRETTY_FUNCTION__));
    return hasConventionalSuffix(MethodSelector.getNameForSlot(0));
  }

  llvm::StringRef PieceName = MethodSelector.getNameForSlot(PieceIndex);
  return isConventional(PieceName) || hasConventionalSuffix(PieceName);
}

bool shouldBeCalledOnce(const ParmVarDecl *Parameter) const {
  return isExplicitlyMarked(Parameter) ||
         (CheckConventionalParameters &&
11
←
Assuming field 'CheckConventionalParameters' is true→
          (isConventional(Parameter->getName()) ||
           hasConventionalSuffix(Parameter->getName())) &&
          isConventional(Parameter->getType()));
12
←
Calling 'CalledOnceChecker::isConventional'→
}

bool shouldBeCalledOnce(const DeclContext *ParamContext,
                        const ParmVarDecl *Param) {
  unsigned ParamIndex = Param->getFunctionScopeIndex();
  if (const auto *Function = dyn_cast<FunctionDecl>(ParamContext)) {
    return shouldBeCalledOnce(Function, ParamIndex);
  }
  if (const auto *Method = dyn_cast<ObjCMethodDecl>(ParamContext)) {
    return shouldBeCalledOnce(Method, ParamIndex);
  }
  return shouldBeCalledOnce(Param);
}

bool shouldBeCalledOnce(const BlockDecl *Block, unsigned ParamIndex) const {
  return shouldBeCalledOnce(Block->getParamDecl(ParamIndex));
}

bool shouldBeCalledOnce(const FunctionDecl *Function,
                        unsigned ParamIndex) const {
  if (ParamIndex >= Function->getNumParams()) {
7
←
Assuming the condition is false→
8
←
Taking false branch→
    return false;
  }
  // 'swift_async' goes first and overrides anything else.
  if (auto ConventionalAsync =
9
←
Taking false branch→
          isConventionalSwiftAsync(Function, ParamIndex)) {
    return ConventionalAsync.getValue();
  }

  return shouldBeCalledOnce(Function->getParamDecl(ParamIndex)) ||
10
←
Calling 'CalledOnceChecker::shouldBeCalledOnce'→
         (CheckConventionalParameters &&
          isOnlyParameterConventional(Function));
}

bool shouldBeCalledOnce(const ObjCMethodDecl *Method,
                        unsigned ParamIndex) const {
  Selector MethodSelector = Method->getSelector();
  if (ParamIndex >= MethodSelector.getNumArgs()) {
    return false;
  }

  // 'swift_async' goes first and overrides anything else.
  if (auto ConventionalAsync = isConventionalSwiftAsync(Method, ParamIndex)) {
    return ConventionalAsync.getValue();
  }

  const ParmVarDecl *Parameter = Method->getParamDecl(ParamIndex);
  return shouldBeCalledOnce(Parameter) ||
         (CheckConventionalParameters &&
          isConventionalSelectorPiece(MethodSelector, ParamIndex,
                                      Parameter->getType()));
}

bool shouldBeCalledOnce(const CallExpr *Call, unsigned ParamIndex) const {
  const FunctionDecl *Function = Call->getDirectCallee();
  return Function5.1
'Function' is non-null
1
'Function' is non-null
 && shouldBeCalledOnce(Function, ParamIndex);
6
←
Calling 'CalledOnceChecker::shouldBeCalledOnce'→
}

bool shouldBeCalledOnce(const ObjCMessageExpr *Message,
                        unsigned ParamIndex) const {
  const ObjCMethodDecl *Method = Message->getMethodDecl();
  return Method && ParamIndex < Method->param_size() &&
         shouldBeCalledOnce(Method, ParamIndex);
}

//===----------------------------------------------------------------------===//
//                               Utility methods
//===----------------------------------------------------------------------===//

bool isCaptured(const ParmVarDecl *Parameter) const {
  if (const BlockDecl *Block = dyn_cast<BlockDecl>(AC.getDecl())) {
    return Block->capturesVariable(Parameter);
  }
  return false;
}

// Return a call site where the block is called exactly once or null otherwise
const Expr *getBlockGuaraneedCallSite(const BlockExpr *Block) const {
  ParentMap &PM = AC.getParentMap();

  // We don't want to track the block through assignments and so on, instead
  // we simply see how the block used and if it's used directly in a call,
  // we decide based on call to what it is.
  //
  // In order to do this, we go up the parents of the block looking for
  // a call or a message expressions.  These might not be immediate parents
  // of the actual block expression due to casts and parens, so we skip them.
  for (const Stmt *Prev = Block, *Current = PM.getParent(Block);
       Current != nullptr; Prev = Current, Current = PM.getParent(Current)) {
    // Skip no-op (for our case) operations.
    if (isa<CastExpr>(Current) || isa<ParenExpr>(Current))
      continue;

    // At this point, Prev represents our block as an immediate child of the
    // call.
    if (const auto *Call = dyn_cast<CallExpr>(Current)) {
      // It might be the call of the Block itself...
      if (Call->getCallee() == Prev)
        return Call;

      // ...or it can be an indirect call of the block.
      return shouldBlockArgumentBeCalledOnce(Call, Prev) ? Call : nullptr;
    }
    if (const auto *Message = dyn_cast<ObjCMessageExpr>(Current)) {
      return shouldBlockArgumentBeCalledOnce(Message, Prev) ? Message
                                                            : nullptr;
    }

    break;
  }

  return nullptr;
}

template <class CallLikeExpr>
bool shouldBlockArgumentBeCalledOnce(const CallLikeExpr *CallOrMessage,
                                     const Stmt *BlockArgument) const {
  // CallExpr::arguments does not interact nicely with llvm::enumerate.
  llvm::ArrayRef<const Expr *> Arguments = llvm::makeArrayRef(
      CallOrMessage->getArgs(), CallOrMessage->getNumArgs());

  for (const auto &Argument : llvm::enumerate(Arguments)) {
    if (Argument.value() == BlockArgument) {
      return shouldBlockArgumentBeCalledOnce(CallOrMessage, Argument.index());
    }
  }

  return false;
}

bool shouldBlockArgumentBeCalledOnce(const CallExpr *Call,
                                     unsigned ParamIndex) const {
  const FunctionDecl *Function = Call->getDirectCallee();
  return shouldBlockArgumentBeCalledOnce(Function, ParamIndex) ||
         shouldBeCalledOnce(Call, ParamIndex);
}

bool shouldBlockArgumentBeCalledOnce(const ObjCMessageExpr *Message,
                                     unsigned ParamIndex) const {
  // At the moment, we don't have any Obj-C methods we want to specifically
  // check in here.
  return shouldBeCalledOnce(Message, ParamIndex);
}

static bool shouldBlockArgumentBeCalledOnce(const FunctionDecl *Function,
                                            unsigned ParamIndex) {
  // There is a list of important API functions that while not following
  // conventions nor being directly annotated, still guarantee that the
  // callback parameter will be called exactly once.
  //
  // Here we check if this is the case.
  return Function &&
         llvm::any_of(KNOWN_CALLED_ONCE_PARAMETERS,
                      [Function, ParamIndex](
                          const KnownCalledOnceParameter &Reference) {
                        return Reference.FunctionName ==
                                   Function->getName() &&
                               Reference.ParamIndex == ParamIndex;
                      });
}

/// Return true if the analyzed function is actually a default implementation
/// of the method that has to be overriden.
///
/// These functions can have tracked parameters, but wouldn't call them
/// because they are not designed to perform any meaningful actions.
///
/// There are a couple of flavors of such default implementations:
///   1. Empty methods or methods with a single return statement
///   2. Methods that have one block with a call to no return function
///   3. Methods with only assertion-like operations
bool isPossiblyEmptyImpl() const {
  if (!isa<ObjCMethodDecl>(AC.getDecl())) {
    // We care only about functions that are not supposed to be called.
    // Only methods can be overriden.
    return false;
  }

  // Case #1 (without return statements)
  if (FunctionCFG.size() == 2) {
    // Method has only two blocks: ENTRY and EXIT.
    // This is equivalent to empty function.
    return true;
  }

  // Case #2
  if (FunctionCFG.size() == 3) {
    const CFGBlock &Entry = FunctionCFG.getEntry();
    if (Entry.succ_empty()) {
      return false;
    }

    const CFGBlock *OnlyBlock = *Entry.succ_begin();
    // Method has only one block, let's see if it has a no-return
    // element.
    if (OnlyBlock && OnlyBlock->hasNoReturnElement()) {
      return true;
    }
    // Fallthrough, CFGs with only one block can fall into #1 and #3 as well.
  }

  // Cases #1 (return statements) and #3.
  //
  // It is hard to detect that something is an assertion or came
  // from assertion.  Here we use a simple heuristic:
  //
  //   - If it came from a macro, it can be an assertion.
  //
  // Additionally, we can't assume a number of basic blocks or the CFG's
  // structure because assertions might include loops and conditions.
  return llvm::all_of(FunctionCFG, [](const CFGBlock *BB) {
    if (!BB) {
      // Unreachable blocks are totally fine.
      return true;
    }

    // Return statements can have sub-expressions that are represented as
    // separate statements of a basic block.  We should allow this.
    // This parent map will be initialized with a parent tree for all
    // subexpressions of the block's return statement (if it has one).
    std::unique_ptr<ParentMap> ReturnChildren;

    return llvm::all_of(
        llvm::reverse(*BB), // we should start with return statements, if we
                            // have any, i.e. from the bottom of the block
        [&ReturnChildren](const CFGElement &Element) {
          if (Optional<CFGStmt> S = Element.getAs<CFGStmt>()) {
            const Stmt *SuspiciousStmt = S->getStmt();

            if (isa<ReturnStmt>(SuspiciousStmt)) {
              // Let's initialize this structure to test whether
              // some further statement is a part of this return.
              ReturnChildren = std::make_unique<ParentMap>(
                  const_cast<Stmt *>(SuspiciousStmt));
              // Return statements are allowed as part of #1.
              return true;
            }

            return SuspiciousStmt->getBeginLoc().isMacroID() ||
                   (ReturnChildren &&
                    ReturnChildren->hasParent(SuspiciousStmt));
          }
          return true;
        });
  });
}

/// Check if parameter with the given index has ever escaped.
bool hasEverEscaped(unsigned Index) const {
  return llvm::any_of(States, [Index](const State &StateForOneBB) {
    return StateForOneBB.getKindFor(Index) == ParameterStatus::Escaped;
  });
}

/// Return status stored for the given basic block.
/// \{
State &getState(const CFGBlock *BB) {
  assert(BB)((BB) ? static_cast<void> (0) : __assert_fail ("BB", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 1294, __PRETTY_FUNCTION__));
  return States[BB->getBlockID()];
}
const State &getState(const CFGBlock *BB) const {
  assert(BB)((BB) ? static_cast<void> (0) : __assert_fail ("BB", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 1298, __PRETTY_FUNCTION__));
  return States[BB->getBlockID()];
}
/// \}

/// Assign status to the given basic block.
///
/// Returns true when the stored status changed.
bool assignState(const CFGBlock *BB, const State &ToAssign) {
  State &Current = getState(BB);
  if (Current == ToAssign) {
    return false;
  }

  Current = ToAssign;
  return true;
}

/// Join all incoming statuses for the given basic block.
State joinSuccessors(const CFGBlock *BB) const {
  auto Succs =
      llvm::make_filter_range(BB->succs(), [this](const CFGBlock *Succ) {
        return Succ && this->getState(Succ).isVisited();
      });
  // We came to this block from somewhere after all.
  assert(!Succs.empty() &&((!Succs.empty() && "Basic block should have at least one visited successor"
) ? static_cast<void> (0) : __assert_fail ("!Succs.empty() && \"Basic block should have at least one visited successor\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 1324, __PRETTY_FUNCTION__))
         "Basic block should have at least one visited successor")((!Succs.empty() && "Basic block should have at least one visited successor"
) ? static_cast<void> (0) : __assert_fail ("!Succs.empty() && \"Basic block should have at least one visited successor\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 1324, __PRETTY_FUNCTION__));

  State Result = getState(*Succs.begin());

  for (const CFGBlock *Succ : llvm::drop_begin(Succs, 1)) {
    Result.join(getState(Succ));
  }

  if (const Expr *Condition = getCondition(BB->getTerminatorStmt())) {
    handleConditional(BB, Condition, Result);
  }

  return Result;
}

void handleConditional(const CFGBlock *BB, const Expr *Condition,
                       State &ToAlter) const {
  handleParameterCheck(BB, Condition, ToAlter);
  if (SuppressOnConventionalErrorPaths) {
    handleConventionalCheck(BB, Condition, ToAlter);
  }
}

void handleParameterCheck(const CFGBlock *BB, const Expr *Condition,
                          State &ToAlter) const {
  // In this function, we try to deal with the following pattern:
  //
  //   if (parameter)
  //     parameter(...);
  //
  // It's not good to show a warning here because clearly 'parameter'
  // couldn't and shouldn't be called on the 'else' path.
  //
  // Let's check if this if statement has a check involving one of
  // the tracked parameters.
  if (const ParmVarDecl *Parameter = findReferencedParmVarDecl(
          Condition,
          /* ShouldRetrieveFromComparisons = */ true)) {
    if (const auto Index = getIndex(*Parameter)) {
      ParameterStatus &CurrentStatus = ToAlter.getStatusFor(*Index);

      // We don't want to deep dive into semantics of the check and
      // figure out if that check was for null or something else.
      // We simply trust the user that they know what they are doing.
      //
      // For this reason, in the following loop we look for the
      // best-looking option.
      for (const CFGBlock *Succ : BB->succs()) {
        if (!Succ)
          continue;

        const ParameterStatus &StatusInSucc =
            getState(Succ).getStatusFor(*Index);

        if (StatusInSucc.isErrorStatus()) {
          continue;
        }

        // Let's use this status instead.
        CurrentStatus = StatusInSucc;

        if (StatusInSucc.getKind() == ParameterStatus::DefinitelyCalled) {
          // This is the best option to have and we already found it.
          break;
        }

        // If we found 'Escaped' first, we still might find 'DefinitelyCalled'
        // on the other branch.  And we prefer the latter.
      }
    }
  }
}

void handleConventionalCheck(const CFGBlock *BB, const Expr *Condition,
                             State &ToAlter) const {
  // Even when the analysis is technically correct, it is a widespread pattern
  // not to call completion handlers in some scenarios.  These usually have
  // typical conditional names, such as 'error' or 'cancel'.
  if (!mentionsAnyOfConventionalNames(Condition)) {
    return;
  }

  for (const auto &IndexedStatus : llvm::enumerate(ToAlter)) {
    const ParmVarDecl *Parameter = getParameter(IndexedStatus.index());
    // Conventions do not apply to explicitly marked parameters.
    if (isExplicitlyMarked(Parameter)) {
      continue;
    }

    ParameterStatus &CurrentStatus = IndexedStatus.value();
    // If we did find that on one of the branches the user uses the callback
    // and doesn't on the other path, we believe that they know what they are
    // doing and trust them.
    //
    // There are two possible scenarios for that:
    //   1. Current status is 'MaybeCalled' and one of the branches is
    //      'DefinitelyCalled'
    //   2. Current status is 'NotCalled' and one of the branches is 'Escaped'
    if (isLosingCall(ToAlter, BB, IndexedStatus.index()) ||
        isLosingEscape(ToAlter, BB, IndexedStatus.index())) {
      CurrentStatus = ParameterStatus::Escaped;
    }
  }
}

bool isLosingCall(const State &StateAfterJoin, const CFGBlock *JoinBlock,
                  unsigned ParameterIndex) const {
  // Let's check if the block represents DefinitelyCalled -> MaybeCalled
  // transition.
  return isLosingJoin(StateAfterJoin, JoinBlock, ParameterIndex,
                      ParameterStatus::MaybeCalled,
                      ParameterStatus::DefinitelyCalled);
}

bool isLosingEscape(const State &StateAfterJoin, const CFGBlock *JoinBlock,
                    unsigned ParameterIndex) const {
  // Let's check if the block represents Escaped -> NotCalled transition.
  return isLosingJoin(StateAfterJoin, JoinBlock, ParameterIndex,
                      ParameterStatus::NotCalled, ParameterStatus::Escaped);
}

bool isLosingJoin(const State &StateAfterJoin, const CFGBlock *JoinBlock,
                  unsigned ParameterIndex, ParameterStatus::Kind AfterJoin,
                  ParameterStatus::Kind BeforeJoin) const {
  assert(!ParameterStatus::isErrorStatus(BeforeJoin) &&((!ParameterStatus::isErrorStatus(BeforeJoin) && ParameterStatus
::isErrorStatus(AfterJoin) && "It's not a losing join if statuses do not represent "
 "correct-to-error transition") ? static_cast<void> (0)
 : __assert_fail ("!ParameterStatus::isErrorStatus(BeforeJoin) && ParameterStatus::isErrorStatus(AfterJoin) && \"It's not a losing join if statuses do not represent \" \"correct-to-error transition\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 1451, __PRETTY_FUNCTION__))
         ParameterStatus::isErrorStatus(AfterJoin) &&((!ParameterStatus::isErrorStatus(BeforeJoin) && ParameterStatus
::isErrorStatus(AfterJoin) && "It's not a losing join if statuses do not represent "
 "correct-to-error transition") ? static_cast<void> (0)
 : __assert_fail ("!ParameterStatus::isErrorStatus(BeforeJoin) && ParameterStatus::isErrorStatus(AfterJoin) && \"It's not a losing join if statuses do not represent \" \"correct-to-error transition\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 1451, __PRETTY_FUNCTION__))
         "It's not a losing join if statuses do not represent "((!ParameterStatus::isErrorStatus(BeforeJoin) && ParameterStatus
::isErrorStatus(AfterJoin) && "It's not a losing join if statuses do not represent "
 "correct-to-error transition") ? static_cast<void> (0)
 : __assert_fail ("!ParameterStatus::isErrorStatus(BeforeJoin) && ParameterStatus::isErrorStatus(AfterJoin) && \"It's not a losing join if statuses do not represent \" \"correct-to-error transition\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 1451, __PRETTY_FUNCTION__))
         "correct-to-error transition")((!ParameterStatus::isErrorStatus(BeforeJoin) && ParameterStatus
::isErrorStatus(AfterJoin) && "It's not a losing join if statuses do not represent "
 "correct-to-error transition") ? static_cast<void> (0)
 : __assert_fail ("!ParameterStatus::isErrorStatus(BeforeJoin) && ParameterStatus::isErrorStatus(AfterJoin) && \"It's not a losing join if statuses do not represent \" \"correct-to-error transition\""
, "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 1451, __PRETTY_FUNCTION__));

  const ParameterStatus &CurrentStatus =
      StateAfterJoin.getStatusFor(ParameterIndex);

  return CurrentStatus.getKind() == AfterJoin &&
         anySuccessorHasStatus(JoinBlock, ParameterIndex, BeforeJoin);
}

/// Return true if any of the successors of the given basic block has
/// a specified status for the given parameter.
bool anySuccessorHasStatus(const CFGBlock *Parent, unsigned ParameterIndex,
                           ParameterStatus::Kind ToFind) const {
  return llvm::any_of(
      Parent->succs(), [this, ParameterIndex, ToFind](const CFGBlock *Succ) {
        return Succ && getState(Succ).getKindFor(ParameterIndex) == ToFind;
      });
}

/// Check given expression that was discovered to escape.
void checkEscapee(const Expr *E) {
  if (const ParmVarDecl *Parameter = findReferencedParmVarDecl(E)) {
    checkEscapee(*Parameter);
  }
}

/// Check given parameter that was discovered to escape.
void checkEscapee(const ParmVarDecl &Parameter) {
  if (auto Index = getIndex(Parameter)) {
    processEscapeFor(*Index);
  }
}

/// Mark all parameters in the current state as 'no-return'.
void markNoReturn() {
  for (ParameterStatus &PS : CurrentState) {
    PS = ParameterStatus::NoReturn;
  }
}

/// Check if the given assignment represents suppression and act on it.
void checkSuppression(const BinaryOperator *Assignment) {
  // Suppression has the following form:
  //    parameter = 0;
  // 0 can be of any form (NULL, nil, etc.)
  if (auto Index = getIndexOfExpression(Assignment->getLHS())) {

    // We don't care what is written in the RHS, it could be whatever
    // we can interpret as 0.
    if (auto Constant =
            Assignment->getRHS()->IgnoreParenCasts()->getIntegerConstantExpr(
                AC.getASTContext())) {

      ParameterStatus &CurrentParamStatus = CurrentState.getStatusFor(*Index);

      if (0 == *Constant && CurrentParamStatus.seenAnyCalls()) {
        // Even though this suppression mechanism is introduced to tackle
        // false positives for multiple calls, the fact that the user has
        // to use suppression can also tell us that we couldn't figure out
        // how different paths cancel each other out.  And if that is true,
        // we will most certainly have false positives about parameters not
        // being called on certain paths.
        //
        // For this reason, we abandon tracking this parameter altogether.
        CurrentParamStatus = ParameterStatus::Reported;
      }
    }
  }
}

1521public:
//===----------------------------------------------------------------------===//
//                            Tree traversal methods
//===----------------------------------------------------------------------===//

void VisitCallExpr(const CallExpr *Call) {
  // This call might be a direct call, i.e. a parameter call...
  checkDirectCall(Call);
  // ... or an indirect call, i.e. when parameter is an argument.
  checkIndirectCall(Call);
1
Calling 'CalledOnceChecker::checkIndirectCall'→
}

void VisitObjCMessageExpr(const ObjCMessageExpr *Message) {
  // The most common situation that we are defending against here is
  // copying a tracked parameter.
  if (const Expr *Receiver = Message->getInstanceReceiver()) {
    checkEscapee(Receiver);
  }
  // Message expressions unlike calls, could not be direct.
  checkIndirectCall(Message);
}

void VisitBlockExpr(const BlockExpr *Block) {
  // Block expressions are tricky.  It is a very common practice to capture
  // completion handlers by blocks and use them there.
  // For this reason, it is important to analyze blocks and report warnings
  // for completion handler misuse in blocks.
  //
  // However, it can be quite difficult to track how the block itself is being
  // used.  The full precise anlysis of that will be similar to alias analysis
  // for completion handlers and can be too heavyweight for a compile-time
  // diagnostic.  Instead, we judge about the immediate use of the block.
  //
  // Here, we try to find a call expression where we know due to conventions,
  // annotations, or other reasons that the block is called once and only
  // once.
  const Expr *CalledOnceCallSite = getBlockGuaraneedCallSite(Block);

  // We need to report this information to the handler because in the
  // situation when we know that the block is called exactly once, we can be
  // stricter in terms of reported diagnostics.
  if (CalledOnceCallSite) {
    Handler.handleBlockThatIsGuaranteedToBeCalledOnce(Block->getBlockDecl());
  } else {
    Handler.handleBlockWithNoGuarantees(Block->getBlockDecl());
  }

  for (const auto &Capture : Block->getBlockDecl()->captures()) {
    if (const auto *Param = dyn_cast<ParmVarDecl>(Capture.getVariable())) {
      if (auto Index = getIndex(*Param)) {
        if (CalledOnceCallSite) {
          // The call site of a block can be considered a call site of the
          // captured parameter we track.
          processCallFor(*Index, CalledOnceCallSite);
        } else {
          // We still should consider this block as an escape for parameter,
          // if we don't know about its call site or the number of time it
          // can be invoked.
          processEscapeFor(*Index);
        }
      }
    }
  }
}

void VisitBinaryOperator(const BinaryOperator *Op) {
  if (Op->getOpcode() == clang::BO_Assign) {
    // Let's check if one of the tracked parameters is assigned into
    // something, and if it is we don't want to track extra variables, so we
    // consider it as an escapee.
    checkEscapee(Op->getRHS());

    // Let's check whether this assignment is a suppression.
    checkSuppression(Op);
  }
}

void VisitDeclStmt(const DeclStmt *DS) {
  // Variable initialization is not assignment and should be handled
  // separately.
  //
  // Multiple declarations can be a part of declaration statement.
  for (const auto *Declaration : DS->getDeclGroup()) {
    if (const auto *Var = dyn_cast<VarDecl>(Declaration)) {
      if (Var->getInit()) {
        checkEscapee(Var->getInit());
      }

      if (Var->hasAttr<CleanupAttr>()) {
        FunctionHasCleanupVars = true;
      }
    }
  }
}

void VisitCStyleCastExpr(const CStyleCastExpr *Cast) {
  // We consider '(void)parameter' as a manual no-op escape.
  // It should be used to explicitly tell the analysis that this parameter
  // is intentionally not called on this path.
  if (Cast->getType().getCanonicalType()->isVoidType()) {
    checkEscapee(Cast->getSubExpr());
  }
}

void VisitObjCAtThrowStmt(const ObjCAtThrowStmt *) {
  // It is OK not to call marked parameters on exceptional paths.
  markNoReturn();
}

1630private:
unsigned size() const { return TrackedParams.size(); }

llvm::Optional<unsigned> getIndexOfCallee(const CallExpr *Call) const {
  return getIndexOfExpression(Call->getCallee());
}

llvm::Optional<unsigned> getIndexOfExpression(const Expr *E) const {
  if (const ParmVarDecl *Parameter = findReferencedParmVarDecl(E)) {
    return getIndex(*Parameter);
  }

  return llvm::None;
}

llvm::Optional<unsigned> getIndex(const ParmVarDecl &Parameter) const {
  // Expected number of parameters that we actually track is 1.
  //
  // Also, the maximum number of declared parameters could not be on a scale
  // of hundreds of thousands.
  //
  // In this setting, linear search seems reasonable and even performs better
  // than bisection.
  ParamSizedVector<const ParmVarDecl *>::const_iterator It =
      llvm::find(TrackedParams, &Parameter);

  if (It != TrackedParams.end()) {
    return It - TrackedParams.begin();
  }

  return llvm::None;
}

const ParmVarDecl *getParameter(unsigned Index) const {
  assert(Index < TrackedParams.size())((Index < TrackedParams.size()) ? static_cast<void> (
0) : __assert_fail ("Index < TrackedParams.size()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/lib/Analysis/CalledOnceCheck.cpp"
, 1664, __PRETTY_FUNCTION__));
  return TrackedParams[Index];
}

const CFG &FunctionCFG;
AnalysisDeclContext &AC;
CalledOnceCheckHandler &Handler;
bool CheckConventionalParameters;
// As of now, we turn this behavior off.  So, we still are going to report
// missing calls on paths that look like it was intentional.
// Technically such reports are true positives, but they can make some users
// grumpy because of the sheer number of warnings.
// It can be turned back on if we decide that we want to have the other way
// around.
bool SuppressOnConventionalErrorPaths = false;

// The user can annotate variable declarations with cleanup functions, which
// essentially imposes a custom destructor logic on that variable.
// It is possible to use it, however, to call tracked parameters on all exits
// from the function.  For this reason, we track the fact that the function
// actually has these.
bool FunctionHasCleanupVars = false;

State CurrentState;
ParamSizedVector<const ParmVarDecl *> TrackedParams;
CFGSizedVector<State> States;
1690};

1692} // end anonymous namespace

1694namespace clang {
1695void checkCalledOnceParameters(AnalysisDeclContext &AC,
                             CalledOnceCheckHandler &Handler,
                             bool CheckConventionalParameters) {
CalledOnceChecker::check(AC, Handler, CheckConventionalParameters);
1699}
1700} // end namespace clang

←

/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/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/DependenceFlags.h"
21	#include "clang/AST/NestedNameSpecifier.h"
22	#include "clang/AST/TemplateName.h"
23	#include "clang/Basic/AddressSpaces.h"
24	#include "clang/Basic/AttrKinds.h"
25	#include "clang/Basic/Diagnostic.h"
26	#include "clang/Basic/ExceptionSpecificationType.h"
27	#include "clang/Basic/LLVM.h"
28	#include "clang/Basic/Linkage.h"
29	#include "clang/Basic/PartialDiagnostic.h"
30	#include "clang/Basic/SourceLocation.h"
31	#include "clang/Basic/Specifiers.h"
32	#include "clang/Basic/Visibility.h"
33	#include "llvm/ADT/APInt.h"
34	#include "llvm/ADT/APSInt.h"
35	#include "llvm/ADT/ArrayRef.h"
36	#include "llvm/ADT/FoldingSet.h"
37	#include "llvm/ADT/None.h"
38	#include "llvm/ADT/Optional.h"
39	#include "llvm/ADT/PointerIntPair.h"
40	#include "llvm/ADT/PointerUnion.h"
41	#include "llvm/ADT/StringRef.h"
42	#include "llvm/ADT/Twine.h"
43	#include "llvm/ADT/iterator_range.h"
44	#include "llvm/Support/Casting.h"
45	#include "llvm/Support/Compiler.h"
46	#include "llvm/Support/ErrorHandling.h"
47	#include "llvm/Support/PointerLikeTypeTraits.h"
48	#include "llvm/Support/TrailingObjects.h"
49	#include "llvm/Support/type_traits.h"
50	#include <cassert>
51	#include <cstddef>
52	#include <cstdint>
53	#include <cstring>
54	#include <string>
55	#include <type_traits>
56	#include <utility>
57
58	namespace clang {
59
60	class ExtQuals;
61	class QualType;
62	class ConceptDecl;
63	class TagDecl;
64	class TemplateParameterList;
65	class Type;
66
67	enum {
68	TypeAlignmentInBits = 4,
69	TypeAlignment = 1 << TypeAlignmentInBits
70	};
71
72	namespace serialization {
73	template <class T> class AbstractTypeReader;
74	template <class T> class AbstractTypeWriter;
75	}
76
77	} // namespace clang
78
79	namespace llvm {
80
81	template <typename T>
82	struct PointerLikeTypeTraits;
83	template<>
84	struct PointerLikeTypeTraits< ::clang::Type*> {
85	static inline void getAsVoidPointer(::clang::Type P) { return P; }
86
87	static inline ::clang::Type getFromVoidPointer(void P) {
88	return static_cast< ::clang::Type*>(P);
89	}
90
91	static constexpr int NumLowBitsAvailable = clang::TypeAlignmentInBits;
92	};
93
94	template<>
95	struct PointerLikeTypeTraits< ::clang::ExtQuals*> {
96	static inline void getAsVoidPointer(::clang::ExtQuals P) { return P; }
97
98	static inline ::clang::ExtQuals getFromVoidPointer(void P) {
99	return static_cast< ::clang::ExtQuals*>(P);
100	}
101
102	static constexpr int NumLowBitsAvailable = clang::TypeAlignmentInBits;
103	};
104
105	} // namespace llvm
106
107	namespace clang {
108
109	class ASTContext;
110	template <typename> class CanQual;
111	class CXXRecordDecl;
112	class DeclContext;
113	class EnumDecl;
114	class Expr;
115	class ExtQualsTypeCommonBase;
116	class FunctionDecl;
117	class IdentifierInfo;
118	class NamedDecl;
119	class ObjCInterfaceDecl;
120	class ObjCProtocolDecl;
121	class ObjCTypeParamDecl;
122	struct PrintingPolicy;
123	class RecordDecl;
124	class Stmt;
125	class TagDecl;
126	class TemplateArgument;
127	class TemplateArgumentListInfo;
128	class TemplateArgumentLoc;
129	class TemplateTypeParmDecl;
130	class TypedefNameDecl;
131	class UnresolvedUsingTypenameDecl;
132
133	using CanQualType = CanQual<Type>;
134
135	// Provide forward declarations for all of the *Type classes.
136	#define TYPE(Class, Base) class Class##Type;
137	#include "clang/AST/TypeNodes.inc"
138
139	/// The collection of all-type qualifiers we support.
140	/// Clang supports five independent qualifiers:
141	/// * C99: const, volatile, and restrict
142	/// * MS: __unaligned
143	/// * Embedded C (TR18037): address spaces
144	/// * Objective C: the GC attributes (none, weak, or strong)
145	class Qualifiers {
146	public:
147	enum TQ { // NOTE: These flags must be kept in sync with DeclSpec::TQ.
148	Const = 0x1,
149	Restrict = 0x2,
150	Volatile = 0x4,
151	CVRMask = Const \| Volatile \| Restrict
152	};
153
154	enum GC {
155	GCNone = 0,
156	Weak,
157	Strong
158	};
159
160	enum ObjCLifetime {
161	/// There is no lifetime qualification on this type.
162	OCL_None,
163
164	/// This object can be modified without requiring retains or
165	/// releases.
166	OCL_ExplicitNone,
167
168	/// Assigning into this object requires the old value to be
169	/// released and the new value to be retained. The timing of the
170	/// release of the old value is inexact: it may be moved to
171	/// immediately after the last known point where the value is
172	/// live.
173	OCL_Strong,
174
175	/// Reading or writing from this object requires a barrier call.
176	OCL_Weak,
177
178	/// Assigning into this object requires a lifetime extension.
179	OCL_Autoreleasing
180	};
181
182	enum {
183	/// The maximum supported address space number.
184	/// 23 bits should be enough for anyone.
185	MaxAddressSpace = 0x7fffffu,
186
187	/// The width of the "fast" qualifier mask.
188	FastWidth = 3,
189
190	/// The fast qualifier mask.
191	FastMask = (1 << FastWidth) - 1
192	};
193
194	/// Returns the common set of qualifiers while removing them from
195	/// the given sets.
196	static Qualifiers removeCommonQualifiers(Qualifiers &L, Qualifiers &R) {
197	// If both are only CVR-qualified, bit operations are sufficient.
198	if (!(L.Mask & ~CVRMask) && !(R.Mask & ~CVRMask)) {
199	Qualifiers Q;
200	Q.Mask = L.Mask & R.Mask;
201	L.Mask &= ~Q.Mask;
202	R.Mask &= ~Q.Mask;
203	return Q;
204	}
205
206	Qualifiers Q;
207	unsigned CommonCRV = L.getCVRQualifiers() & R.getCVRQualifiers();
208	Q.addCVRQualifiers(CommonCRV);
209	L.removeCVRQualifiers(CommonCRV);
210	R.removeCVRQualifiers(CommonCRV);
211
212	if (L.getObjCGCAttr() == R.getObjCGCAttr()) {
213	Q.setObjCGCAttr(L.getObjCGCAttr());
214	L.removeObjCGCAttr();
215	R.removeObjCGCAttr();
216	}
217
218	if (L.getObjCLifetime() == R.getObjCLifetime()) {
219	Q.setObjCLifetime(L.getObjCLifetime());
220	L.removeObjCLifetime();
221	R.removeObjCLifetime();
222	}
223
224	if (L.getAddressSpace() == R.getAddressSpace()) {
225	Q.setAddressSpace(L.getAddressSpace());
226	L.removeAddressSpace();
227	R.removeAddressSpace();
228	}
229	return Q;
230	}
231
232	static Qualifiers fromFastMask(unsigned Mask) {
233	Qualifiers Qs;
234	Qs.addFastQualifiers(Mask);
235	return Qs;
236	}
237
238	static Qualifiers fromCVRMask(unsigned CVR) {
239	Qualifiers Qs;
240	Qs.addCVRQualifiers(CVR);
241	return Qs;
242	}
243
244	static Qualifiers fromCVRUMask(unsigned CVRU) {
245	Qualifiers Qs;
246	Qs.addCVRUQualifiers(CVRU);
247	return Qs;
248	}
249
250	// Deserialize qualifiers from an opaque representation.
251	static Qualifiers fromOpaqueValue(unsigned opaque) {
252	Qualifiers Qs;
253	Qs.Mask = opaque;
254	return Qs;
255	}
256
257	// Serialize these qualifiers into an opaque representation.
258	unsigned getAsOpaqueValue() const {
259	return Mask;
260	}
261
262	bool hasConst() const { return Mask & Const; }
263	bool hasOnlyConst() const { return Mask == Const; }
264	void removeConst() { Mask &= ~Const; }
265	void addConst() { Mask \|= Const; }
266
267	bool hasVolatile() const { return Mask & Volatile; }
268	bool hasOnlyVolatile() const { return Mask == Volatile; }
269	void removeVolatile() { Mask &= ~Volatile; }
270	void addVolatile() { Mask \|= Volatile; }
271
272	bool hasRestrict() const { return Mask & Restrict; }
273	bool hasOnlyRestrict() const { return Mask == Restrict; }
274	void removeRestrict() { Mask &= ~Restrict; }
275	void addRestrict() { Mask \|= Restrict; }
276
277	bool hasCVRQualifiers() const { return getCVRQualifiers(); }
278	unsigned getCVRQualifiers() const { return Mask & CVRMask; }
279	unsigned getCVRUQualifiers() const { return Mask & (CVRMask \| UMask); }
280
281	void setCVRQualifiers(unsigned mask) {
282	assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits")((!(mask & ~CVRMask) && "bitmask contains non-CVR bits" ) ? static_cast<void> (0) : __assert_fail ("!(mask & ~CVRMask) && \"bitmask contains non-CVR bits\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 282, __PRETTY_FUNCTION__));
283	Mask = (Mask & ~CVRMask) \| mask;
284	}
285	void removeCVRQualifiers(unsigned mask) {
286	assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits")((!(mask & ~CVRMask) && "bitmask contains non-CVR bits" ) ? static_cast<void> (0) : __assert_fail ("!(mask & ~CVRMask) && \"bitmask contains non-CVR bits\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 286, __PRETTY_FUNCTION__));
287	Mask &= ~mask;
288	}
289	void removeCVRQualifiers() {
290	removeCVRQualifiers(CVRMask);
291	}
292	void addCVRQualifiers(unsigned mask) {
293	assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits")((!(mask & ~CVRMask) && "bitmask contains non-CVR bits" ) ? static_cast<void> (0) : __assert_fail ("!(mask & ~CVRMask) && \"bitmask contains non-CVR bits\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 293, __PRETTY_FUNCTION__));
294	Mask \|= mask;
295	}
296	void addCVRUQualifiers(unsigned mask) {
297	assert(!(mask & ~CVRMask & ~UMask) && "bitmask contains non-CVRU bits")((!(mask & ~CVRMask & ~UMask) && "bitmask contains non-CVRU bits" ) ? static_cast<void> (0) : __assert_fail ("!(mask & ~CVRMask & ~UMask) && \"bitmask contains non-CVRU bits\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 297, __PRETTY_FUNCTION__));
298	Mask \|= mask;
299	}
300
301	bool hasUnaligned() const { return Mask & UMask; }
302	void setUnaligned(bool flag) {
303	Mask = (Mask & ~UMask) \| (flag ? UMask : 0);
304	}
305	void removeUnaligned() { Mask &= ~UMask; }
306	void addUnaligned() { Mask \|= UMask; }
307
308	bool hasObjCGCAttr() const { return Mask & GCAttrMask; }
309	GC getObjCGCAttr() const { return GC((Mask & GCAttrMask) >> GCAttrShift); }
310	void setObjCGCAttr(GC type) {
311	Mask = (Mask & ~GCAttrMask) \| (type << GCAttrShift);
312	}
313	void removeObjCGCAttr() { setObjCGCAttr(GCNone); }
314	void addObjCGCAttr(GC type) {
315	assert(type)((type) ? static_cast<void> (0) : __assert_fail ("type" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 315, __PRETTY_FUNCTION__));
316	setObjCGCAttr(type);
317	}
318	Qualifiers withoutObjCGCAttr() const {
319	Qualifiers qs = *this;
320	qs.removeObjCGCAttr();
321	return qs;
322	}
323	Qualifiers withoutObjCLifetime() const {
324	Qualifiers qs = *this;
325	qs.removeObjCLifetime();
326	return qs;
327	}
328	Qualifiers withoutAddressSpace() const {
329	Qualifiers qs = *this;
330	qs.removeAddressSpace();
331	return qs;
332	}
333
334	bool hasObjCLifetime() const { return Mask & LifetimeMask; }
335	ObjCLifetime getObjCLifetime() const {
336	return ObjCLifetime((Mask & LifetimeMask) >> LifetimeShift);
337	}
338	void setObjCLifetime(ObjCLifetime type) {
339	Mask = (Mask & ~LifetimeMask) \| (type << LifetimeShift);
340	}
341	void removeObjCLifetime() { setObjCLifetime(OCL_None); }
342	void addObjCLifetime(ObjCLifetime type) {
343	assert(type)((type) ? static_cast<void> (0) : __assert_fail ("type" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 343, __PRETTY_FUNCTION__));
344	assert(!hasObjCLifetime())((!hasObjCLifetime()) ? static_cast<void> (0) : __assert_fail ("!hasObjCLifetime()", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 344, __PRETTY_FUNCTION__));
345	Mask \|= (type << LifetimeShift);
346	}
347
348	/// True if the lifetime is neither None or ExplicitNone.
349	bool hasNonTrivialObjCLifetime() const {
350	ObjCLifetime lifetime = getObjCLifetime();
351	return (lifetime > OCL_ExplicitNone);
352	}
353
354	/// True if the lifetime is either strong or weak.
355	bool hasStrongOrWeakObjCLifetime() const {
356	ObjCLifetime lifetime = getObjCLifetime();
357	return (lifetime == OCL_Strong \|\| lifetime == OCL_Weak);
358	}
359
360	bool hasAddressSpace() const { return Mask & AddressSpaceMask; }
361	LangAS getAddressSpace() const {
362	return static_cast<LangAS>(Mask >> AddressSpaceShift);
363	}
364	bool hasTargetSpecificAddressSpace() const {
365	return isTargetAddressSpace(getAddressSpace());
366	}
367	/// Get the address space attribute value to be printed by diagnostics.
368	unsigned getAddressSpaceAttributePrintValue() const {
369	auto Addr = getAddressSpace();
370	// This function is not supposed to be used with language specific
371	// address spaces. If that happens, the diagnostic message should consider
372	// printing the QualType instead of the address space value.
373	assert(Addr == LangAS::Default \|\| hasTargetSpecificAddressSpace())((Addr == LangAS::Default \|\| hasTargetSpecificAddressSpace()) ? static_cast<void> (0) : __assert_fail ("Addr == LangAS::Default \|\| hasTargetSpecificAddressSpace()" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 373, __PRETTY_FUNCTION__));
374	if (Addr != LangAS::Default)
375	return toTargetAddressSpace(Addr);
376	// TODO: The diagnostic messages where Addr may be 0 should be fixed
377	// since it cannot differentiate the situation where 0 denotes the default
378	// address space or user specified __attribute__((address_space(0))).
379	return 0;
380	}
381	void setAddressSpace(LangAS space) {
382	assert((unsigned)space <= MaxAddressSpace)(((unsigned)space <= MaxAddressSpace) ? static_cast<void > (0) : __assert_fail ("(unsigned)space <= MaxAddressSpace" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 382, __PRETTY_FUNCTION__));
383	Mask = (Mask & ~AddressSpaceMask)
384	\| (((uint32_t) space) << AddressSpaceShift);
385	}
386	void removeAddressSpace() { setAddressSpace(LangAS::Default); }
387	void addAddressSpace(LangAS space) {
388	assert(space != LangAS::Default)((space != LangAS::Default) ? static_cast<void> (0) : __assert_fail ("space != LangAS::Default", "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 388, __PRETTY_FUNCTION__));
389	setAddressSpace(space);
390	}
391
392	// Fast qualifiers are those that can be allocated directly
393	// on a QualType object.
394	bool hasFastQualifiers() const { return getFastQualifiers(); }
395	unsigned getFastQualifiers() const { return Mask & FastMask; }
396	void setFastQualifiers(unsigned mask) {
397	assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits")((!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits" ) ? static_cast<void> (0) : __assert_fail ("!(mask & ~FastMask) && \"bitmask contains non-fast qualifier bits\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 397, __PRETTY_FUNCTION__));
398	Mask = (Mask & ~FastMask) \| mask;
399	}
400	void removeFastQualifiers(unsigned mask) {
401	assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits")((!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits" ) ? static_cast<void> (0) : __assert_fail ("!(mask & ~FastMask) && \"bitmask contains non-fast qualifier bits\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 401, __PRETTY_FUNCTION__));
402	Mask &= ~mask;
403	}
404	void removeFastQualifiers() {
405	removeFastQualifiers(FastMask);
406	}
407	void addFastQualifiers(unsigned mask) {
408	assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits")((!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits" ) ? static_cast<void> (0) : __assert_fail ("!(mask & ~FastMask) && \"bitmask contains non-fast qualifier bits\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 408, __PRETTY_FUNCTION__));
409	Mask \|= mask;
410	}
411
412	/// Return true if the set contains any qualifiers which require an ExtQuals
413	/// node to be allocated.
414	bool hasNonFastQualifiers() const { return Mask & ~FastMask; }
415	Qualifiers getNonFastQualifiers() const {
416	Qualifiers Quals = *this;
417	Quals.setFastQualifiers(0);
418	return Quals;
419	}
420
421	/// Return true if the set contains any qualifiers.
422	bool hasQualifiers() const { return Mask; }
423	bool empty() const { return !Mask; }
424
425	/// Add the qualifiers from the given set to this set.
426	void addQualifiers(Qualifiers Q) {
427	// If the other set doesn't have any non-boolean qualifiers, just
428	// bit-or it in.
429	if (!(Q.Mask & ~CVRMask))
430	Mask \|= Q.Mask;
431	else {
432	Mask \|= (Q.Mask & CVRMask);
433	if (Q.hasAddressSpace())
434	addAddressSpace(Q.getAddressSpace());
435	if (Q.hasObjCGCAttr())
436	addObjCGCAttr(Q.getObjCGCAttr());
437	if (Q.hasObjCLifetime())
438	addObjCLifetime(Q.getObjCLifetime());
439	}
440	}
441
442	/// Remove the qualifiers from the given set from this set.
443	void removeQualifiers(Qualifiers Q) {
444	// If the other set doesn't have any non-boolean qualifiers, just
445	// bit-and the inverse in.
446	if (!(Q.Mask & ~CVRMask))
447	Mask &= ~Q.Mask;
448	else {
449	Mask &= ~(Q.Mask & CVRMask);
450	if (getObjCGCAttr() == Q.getObjCGCAttr())
451	removeObjCGCAttr();
452	if (getObjCLifetime() == Q.getObjCLifetime())
453	removeObjCLifetime();
454	if (getAddressSpace() == Q.getAddressSpace())
455	removeAddressSpace();
456	}
457	}
458
459	/// Add the qualifiers from the given set to this set, given that
460	/// they don't conflict.
461	void addConsistentQualifiers(Qualifiers qs) {
462	assert(getAddressSpace() == qs.getAddressSpace() \|\|((getAddressSpace() == qs.getAddressSpace() \|\| !hasAddressSpace () \|\| !qs.hasAddressSpace()) ? static_cast<void> (0) : __assert_fail ("getAddressSpace() == qs.getAddressSpace() \|\| !hasAddressSpace() \|\| !qs.hasAddressSpace()" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 463, __PRETTY_FUNCTION__))
463	!hasAddressSpace() \|\| !qs.hasAddressSpace())((getAddressSpace() == qs.getAddressSpace() \|\| !hasAddressSpace () \|\| !qs.hasAddressSpace()) ? static_cast<void> (0) : __assert_fail ("getAddressSpace() == qs.getAddressSpace() \|\| !hasAddressSpace() \|\| !qs.hasAddressSpace()" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 463, __PRETTY_FUNCTION__));
464	assert(getObjCGCAttr() == qs.getObjCGCAttr() \|\|((getObjCGCAttr() == qs.getObjCGCAttr() \|\| !hasObjCGCAttr() \|\| !qs.hasObjCGCAttr()) ? static_cast<void> (0) : __assert_fail ("getObjCGCAttr() == qs.getObjCGCAttr() \|\| !hasObjCGCAttr() \|\| !qs.hasObjCGCAttr()" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 465, __PRETTY_FUNCTION__))
465	!hasObjCGCAttr() \|\| !qs.hasObjCGCAttr())((getObjCGCAttr() == qs.getObjCGCAttr() \|\| !hasObjCGCAttr() \|\| !qs.hasObjCGCAttr()) ? static_cast<void> (0) : __assert_fail ("getObjCGCAttr() == qs.getObjCGCAttr() \|\| !hasObjCGCAttr() \|\| !qs.hasObjCGCAttr()" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 465, __PRETTY_FUNCTION__));
466	assert(getObjCLifetime() == qs.getObjCLifetime() \|\|((getObjCLifetime() == qs.getObjCLifetime() \|\| !hasObjCLifetime () \|\| !qs.hasObjCLifetime()) ? static_cast<void> (0) : __assert_fail ("getObjCLifetime() == qs.getObjCLifetime() \|\| !hasObjCLifetime() \|\| !qs.hasObjCLifetime()" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 467, __PRETTY_FUNCTION__))
467	!hasObjCLifetime() \|\| !qs.hasObjCLifetime())((getObjCLifetime() == qs.getObjCLifetime() \|\| !hasObjCLifetime () \|\| !qs.hasObjCLifetime()) ? static_cast<void> (0) : __assert_fail ("getObjCLifetime() == qs.getObjCLifetime() \|\| !hasObjCLifetime() \|\| !qs.hasObjCLifetime()" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 467, __PRETTY_FUNCTION__));
468	Mask \|= qs.Mask;
469	}
470
471	/// Returns true if address space A is equal to or a superset of B.
472	/// OpenCL v2.0 defines conversion rules (OpenCLC v2.0 s6.5.5) and notion of
473	/// overlapping address spaces.
474	/// CL1.1 or CL1.2:
475	/// every address space is a superset of itself.
476	/// CL2.0 adds:
477	/// __generic is a superset of any address space except for __constant.
478	static bool isAddressSpaceSupersetOf(LangAS A, LangAS B) {
479	// Address spaces must match exactly.
480	return A == B \|\|
481	// Otherwise in OpenCLC v2.0 s6.5.5: every address space except
482	// for __constant can be used as __generic.
483	(A == LangAS::opencl_generic && B != LangAS::opencl_constant) \|\|
484	// We also define global_device and global_host address spaces,
485	// to distinguish global pointers allocated on host from pointers
486	// allocated on device, which are a subset of __global.
487	(A == LangAS::opencl_global && (B == LangAS::opencl_global_device \|\|
488	B == LangAS::opencl_global_host)) \|\|
489	// Consider pointer size address spaces to be equivalent to default.
490	((isPtrSizeAddressSpace(A) \|\| A == LangAS::Default) &&
491	(isPtrSizeAddressSpace(B) \|\| B == LangAS::Default));
492	}
493
494	/// Returns true if the address space in these qualifiers is equal to or
495	/// a superset of the address space in the argument qualifiers.
496	bool isAddressSpaceSupersetOf(Qualifiers other) const {
497	return isAddressSpaceSupersetOf(getAddressSpace(), other.getAddressSpace());
498	}
499
500	/// Determines if these qualifiers compatibly include another set.
501	/// Generally this answers the question of whether an object with the other
502	/// qualifiers can be safely used as an object with these qualifiers.
503	bool compatiblyIncludes(Qualifiers other) const {
504	return isAddressSpaceSupersetOf(other) &&
505	// ObjC GC qualifiers can match, be added, or be removed, but can't
506	// be changed.
507	(getObjCGCAttr() == other.getObjCGCAttr() \|\| !hasObjCGCAttr() \|\|
508	!other.hasObjCGCAttr()) &&
509	// ObjC lifetime qualifiers must match exactly.
510	getObjCLifetime() == other.getObjCLifetime() &&
511	// CVR qualifiers may subset.
512	(((Mask & CVRMask) \| (other.Mask & CVRMask)) == (Mask & CVRMask)) &&
513	// U qualifier may superset.
514	(!other.hasUnaligned() \|\| hasUnaligned());
515	}
516
517	/// Determines if these qualifiers compatibly include another set of
518	/// qualifiers from the narrow perspective of Objective-C ARC lifetime.
519	///
520	/// One set of Objective-C lifetime qualifiers compatibly includes the other
521	/// if the lifetime qualifiers match, or if both are non-__weak and the
522	/// including set also contains the 'const' qualifier, or both are non-__weak
523	/// and one is None (which can only happen in non-ARC modes).
524	bool compatiblyIncludesObjCLifetime(Qualifiers other) const {
525	if (getObjCLifetime() == other.getObjCLifetime())
526	return true;
527
528	if (getObjCLifetime() == OCL_Weak \|\| other.getObjCLifetime() == OCL_Weak)
529	return false;
530
531	if (getObjCLifetime() == OCL_None \|\| other.getObjCLifetime() == OCL_None)
532	return true;
533
534	return hasConst();
535	}
536
537	/// Determine whether this set of qualifiers is a strict superset of
538	/// another set of qualifiers, not considering qualifier compatibility.
539	bool isStrictSupersetOf(Qualifiers Other) const;
540
541	bool operator==(Qualifiers Other) const { return Mask == Other.Mask; }
542	bool operator!=(Qualifiers Other) const { return Mask != Other.Mask; }
543
544	explicit operator bool() const { return hasQualifiers(); }
545
546	Qualifiers &operator+=(Qualifiers R) {
547	addQualifiers(R);
548	return *this;
549	}
550
551	// Union two qualifier sets. If an enumerated qualifier appears
552	// in both sets, use the one from the right.
553	friend Qualifiers operator+(Qualifiers L, Qualifiers R) {
554	L += R;
555	return L;
556	}
557
558	Qualifiers &operator-=(Qualifiers R) {
559	removeQualifiers(R);
560	return *this;
561	}
562
563	/// Compute the difference between two qualifier sets.
564	friend Qualifiers operator-(Qualifiers L, Qualifiers R) {
565	L -= R;
566	return L;
567	}
568
569	std::string getAsString() const;
570	std::string getAsString(const PrintingPolicy &Policy) const;
571
572	static std::string getAddrSpaceAsString(LangAS AS);
573
574	bool isEmptyWhenPrinted(const PrintingPolicy &Policy) const;
575	void print(raw_ostream &OS, const PrintingPolicy &Policy,
576	bool appendSpaceIfNonEmpty = false) const;
577
578	void Profile(llvm::FoldingSetNodeID &ID) const {
579	ID.AddInteger(Mask);
580	}
581
582	private:
583	// bits: \|0 1 2\|3\|4 .. 5\|6 .. 8\|9 ... 31\|
584	// \|C R V\|U\|GCAttr\|Lifetime\|AddressSpace\|
585	uint32_t Mask = 0;
586
587	static const uint32_t UMask = 0x8;
588	static const uint32_t UShift = 3;
589	static const uint32_t GCAttrMask = 0x30;
590	static const uint32_t GCAttrShift = 4;
591	static const uint32_t LifetimeMask = 0x1C0;
592	static const uint32_t LifetimeShift = 6;
593	static const uint32_t AddressSpaceMask =
594	~(CVRMask \| UMask \| GCAttrMask \| LifetimeMask);
595	static const uint32_t AddressSpaceShift = 9;
596	};
597
598	/// A std::pair-like structure for storing a qualified type split
599	/// into its local qualifiers and its locally-unqualified type.
600	struct SplitQualType {
601	/// The locally-unqualified type.
602	const Type *Ty = nullptr;
603
604	/// The local qualifiers.
605	Qualifiers Quals;
606
607	SplitQualType() = default;
608	SplitQualType(const Type *ty, Qualifiers qs) : Ty(ty), Quals(qs) {}
609
610	SplitQualType getSingleStepDesugaredType() const; // end of this file
611
612	// Make std::tie work.
613	std::pair<const Type *,Qualifiers> asPair() const {
614	return std::pair<const Type *, Qualifiers>(Ty, Quals);
615	}
616
617	friend bool operator==(SplitQualType a, SplitQualType b) {
618	return a.Ty == b.Ty && a.Quals == b.Quals;
619	}
620	friend bool operator!=(SplitQualType a, SplitQualType b) {
621	return a.Ty != b.Ty \|\| a.Quals != b.Quals;
622	}
623	};
624
625	/// The kind of type we are substituting Objective-C type arguments into.
626	///
627	/// The kind of substitution affects the replacement of type parameters when
628	/// no concrete type information is provided, e.g., when dealing with an
629	/// unspecialized type.
630	enum class ObjCSubstitutionContext {
631	/// An ordinary type.
632	Ordinary,
633
634	/// The result type of a method or function.
635	Result,
636
637	/// The parameter type of a method or function.
638	Parameter,
639
640	/// The type of a property.
641	Property,
642
643	/// The superclass of a type.
644	Superclass,
645	};
646
647	/// A (possibly-)qualified type.
648	///
649	/// For efficiency, we don't store CV-qualified types as nodes on their
650	/// own: instead each reference to a type stores the qualifiers. This
651	/// greatly reduces the number of nodes we need to allocate for types (for
652	/// example we only need one for 'int', 'const int', 'volatile int',
653	/// 'const volatile int', etc).
654	///
655	/// As an added efficiency bonus, instead of making this a pair, we
656	/// just store the two bits we care about in the low bits of the
657	/// pointer. To handle the packing/unpacking, we make QualType be a
658	/// simple wrapper class that acts like a smart pointer. A third bit
659	/// indicates whether there are extended qualifiers present, in which
660	/// case the pointer points to a special structure.
661	class QualType {
662	friend class QualifierCollector;
663
664	// Thankfully, these are efficiently composable.
665	llvm::PointerIntPair<llvm::PointerUnion<const Type , const ExtQuals >,
666	Qualifiers::FastWidth> Value;
667
668	const ExtQuals *getExtQualsUnsafe() const {
669	return Value.getPointer().get<const ExtQuals*>();
670	}
671
672	const Type *getTypePtrUnsafe() const {
673	return Value.getPointer().get<const Type*>();
674	}
675
676	const ExtQualsTypeCommonBase *getCommonPtr() const {
677	assert(!isNull() && "Cannot retrieve a NULL type pointer")((!isNull() && "Cannot retrieve a NULL type pointer") ? static_cast<void> (0) : __assert_fail ("!isNull() && \"Cannot retrieve a NULL type pointer\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 677, __PRETTY_FUNCTION__));
678	auto CommonPtrVal = reinterpret_cast<uintptr_t>(Value.getOpaqueValue());
679	CommonPtrVal &= ~(uintptr_t)((1 << TypeAlignmentInBits) - 1);
680	return reinterpret_cast<ExtQualsTypeCommonBase*>(CommonPtrVal);
681	}
682
683	public:
684	QualType() = default;
685	QualType(const Type *Ptr, unsigned Quals) : Value(Ptr, Quals) {}
686	QualType(const ExtQuals *Ptr, unsigned Quals) : Value(Ptr, Quals) {}
687
688	unsigned getLocalFastQualifiers() const { return Value.getInt(); }
689	void setLocalFastQualifiers(unsigned Quals) { Value.setInt(Quals); }
690
691	/// Retrieves a pointer to the underlying (unqualified) type.
692	///
693	/// This function requires that the type not be NULL. If the type might be
694	/// NULL, use the (slightly less efficient) \c getTypePtrOrNull().
695	const Type *getTypePtr() const;
696
697	const Type *getTypePtrOrNull() const;
698
699	/// Retrieves a pointer to the name of the base type.
700	const IdentifierInfo *getBaseTypeIdentifier() const;
701
702	/// Divides a QualType into its unqualified type and a set of local
703	/// qualifiers.
704	SplitQualType split() const;
705
706	void *getAsOpaquePtr() const { return Value.getOpaqueValue(); }
707
708	static QualType getFromOpaquePtr(const void *Ptr) {
709	QualType T;
710	T.Value.setFromOpaqueValue(const_cast<void*>(Ptr));
711	return T;
712	}
713
714	const Type &operator*() const {
715	return *getTypePtr();
716	}
717
718	const Type *operator->() const {
719	return getTypePtr();
720	}
721
722	bool isCanonical() const;
723	bool isCanonicalAsParam() const;
724
725	/// Return true if this QualType doesn't point to a type yet.
726	bool isNull() const {
727	return Value.getPointer().isNull();
728	}
729
730	/// Determine whether this particular QualType instance has the
731	/// "const" qualifier set, without looking through typedefs that may have
732	/// added "const" at a different level.
733	bool isLocalConstQualified() const {
734	return (getLocalFastQualifiers() & Qualifiers::Const);
735	}
736
737	/// Determine whether this type is const-qualified.
738	bool isConstQualified() const;
739
740	/// Determine whether this particular QualType instance has the
741	/// "restrict" qualifier set, without looking through typedefs that may have
742	/// added "restrict" at a different level.
743	bool isLocalRestrictQualified() const {
744	return (getLocalFastQualifiers() & Qualifiers::Restrict);
745	}
746
747	/// Determine whether this type is restrict-qualified.
748	bool isRestrictQualified() const;
749
750	/// Determine whether this particular QualType instance has the
751	/// "volatile" qualifier set, without looking through typedefs that may have
752	/// added "volatile" at a different level.
753	bool isLocalVolatileQualified() const {
754	return (getLocalFastQualifiers() & Qualifiers::Volatile);
755	}
756
757	/// Determine whether this type is volatile-qualified.
758	bool isVolatileQualified() const;
759
760	/// Determine whether this particular QualType instance has any
761	/// qualifiers, without looking through any typedefs that might add
762	/// qualifiers at a different level.
763	bool hasLocalQualifiers() const {
764	return getLocalFastQualifiers() \|\| hasLocalNonFastQualifiers();
765	}
766
767	/// Determine whether this type has any qualifiers.
768	bool hasQualifiers() const;
769
770	/// Determine whether this particular QualType instance has any
771	/// "non-fast" qualifiers, e.g., those that are stored in an ExtQualType
772	/// instance.
773	bool hasLocalNonFastQualifiers() const {
774	return Value.getPointer().is<const ExtQuals*>();
775	}
776
777	/// Retrieve the set of qualifiers local to this particular QualType
778	/// instance, not including any qualifiers acquired through typedefs or
779	/// other sugar.
780	Qualifiers getLocalQualifiers() const;
781
782	/// Retrieve the set of qualifiers applied to this type.
783	Qualifiers getQualifiers() const;
784
785	/// Retrieve the set of CVR (const-volatile-restrict) qualifiers
786	/// local to this particular QualType instance, not including any qualifiers
787	/// acquired through typedefs or other sugar.
788	unsigned getLocalCVRQualifiers() const {
789	return getLocalFastQualifiers();
790	}
791
792	/// Retrieve the set of CVR (const-volatile-restrict) qualifiers
793	/// applied to this type.
794	unsigned getCVRQualifiers() const;
795
796	bool isConstant(const ASTContext& Ctx) const {
797	return QualType::isConstant(*this, Ctx);
798	}
799
800	/// Determine whether this is a Plain Old Data (POD) type (C++ 3.9p10).
801	bool isPODType(const ASTContext &Context) const;
802
803	/// Return true if this is a POD type according to the rules of the C++98
804	/// standard, regardless of the current compilation's language.
805	bool isCXX98PODType(const ASTContext &Context) const;
806
807	/// Return true if this is a POD type according to the more relaxed rules
808	/// of the C++11 standard, regardless of the current compilation's language.
809	/// (C++0x [basic.types]p9). Note that, unlike
810	/// CXXRecordDecl::isCXX11StandardLayout, this takes DRs into account.
811	bool isCXX11PODType(const ASTContext &Context) const;
812
813	/// Return true if this is a trivial type per (C++0x [basic.types]p9)
814	bool isTrivialType(const ASTContext &Context) const;
815
816	/// Return true if this is a trivially copyable type (C++0x [basic.types]p9)
817	bool isTriviallyCopyableType(const ASTContext &Context) const;
818
819
820	/// Returns true if it is a class and it might be dynamic.
821	bool mayBeDynamicClass() const;
822
823	/// Returns true if it is not a class or if the class might not be dynamic.
824	bool mayBeNotDynamicClass() const;
825
826	// Don't promise in the API that anything besides 'const' can be
827	// easily added.
828
829	/// Add the `const` type qualifier to this QualType.
830	void addConst() {
831	addFastQualifiers(Qualifiers::Const);
832	}
833	QualType withConst() const {
834	return withFastQualifiers(Qualifiers::Const);
835	}
836
837	/// Add the `volatile` type qualifier to this QualType.
838	void addVolatile() {
839	addFastQualifiers(Qualifiers::Volatile);
840	}
841	QualType withVolatile() const {
842	return withFastQualifiers(Qualifiers::Volatile);
843	}
844
845	/// Add the `restrict` qualifier to this QualType.
846	void addRestrict() {
847	addFastQualifiers(Qualifiers::Restrict);
848	}
849	QualType withRestrict() const {
850	return withFastQualifiers(Qualifiers::Restrict);
851	}
852
853	QualType withCVRQualifiers(unsigned CVR) const {
854	return withFastQualifiers(CVR);
855	}
856
857	void addFastQualifiers(unsigned TQs) {
858	assert(!(TQs & ~Qualifiers::FastMask)((!(TQs & ~Qualifiers::FastMask) && "non-fast qualifier bits set in mask!" ) ? static_cast<void> (0) : __assert_fail ("!(TQs & ~Qualifiers::FastMask) && \"non-fast qualifier bits set in mask!\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 859, __PRETTY_FUNCTION__))
859	&& "non-fast qualifier bits set in mask!")((!(TQs & ~Qualifiers::FastMask) && "non-fast qualifier bits set in mask!" ) ? static_cast<void> (0) : __assert_fail ("!(TQs & ~Qualifiers::FastMask) && \"non-fast qualifier bits set in mask!\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 859, __PRETTY_FUNCTION__));
860	Value.setInt(Value.getInt() \| TQs);
861	}
862
863	void removeLocalConst();
864	void removeLocalVolatile();
865	void removeLocalRestrict();
866	void removeLocalCVRQualifiers(unsigned Mask);
867
868	void removeLocalFastQualifiers() { Value.setInt(0); }
869	void removeLocalFastQualifiers(unsigned Mask) {
870	assert(!(Mask & ~Qualifiers::FastMask) && "mask has non-fast qualifiers")((!(Mask & ~Qualifiers::FastMask) && "mask has non-fast qualifiers" ) ? static_cast<void> (0) : __assert_fail ("!(Mask & ~Qualifiers::FastMask) && \"mask has non-fast qualifiers\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 870, __PRETTY_FUNCTION__));
871	Value.setInt(Value.getInt() & ~Mask);
872	}
873
874	// Creates a type with the given qualifiers in addition to any
875	// qualifiers already on this type.
876	QualType withFastQualifiers(unsigned TQs) const {
877	QualType T = *this;
878	T.addFastQualifiers(TQs);
879	return T;
880	}
881
882	// Creates a type with exactly the given fast qualifiers, removing
883	// any existing fast qualifiers.
884	QualType withExactLocalFastQualifiers(unsigned TQs) const {
885	return withoutLocalFastQualifiers().withFastQualifiers(TQs);
886	}
887
888	// Removes fast qualifiers, but leaves any extended qualifiers in place.
889	QualType withoutLocalFastQualifiers() const {
890	QualType T = *this;
891	T.removeLocalFastQualifiers();
892	return T;
893	}
894
895	QualType getCanonicalType() const;
896
897	/// Return this type with all of the instance-specific qualifiers
898	/// removed, but without removing any qualifiers that may have been applied
899	/// through typedefs.
900	QualType getLocalUnqualifiedType() const { return QualType(getTypePtr(), 0); }
901
902	/// Retrieve the unqualified variant of the given type,
903	/// removing as little sugar as possible.
904	///
905	/// This routine looks through various kinds of sugar to find the
906	/// least-desugared type that is unqualified. For example, given:
907	///
908	/// \code
909	/// typedef int Integer;
910	/// typedef const Integer CInteger;
911	/// typedef CInteger DifferenceType;
912	/// \endcode
913	///
914	/// Executing \c getUnqualifiedType() on the type \c DifferenceType will
915	/// desugar until we hit the type \c Integer, which has no qualifiers on it.
916	///
917	/// The resulting type might still be qualified if it's sugar for an array
918	/// type. To strip qualifiers even from within a sugared array type, use
919	/// ASTContext::getUnqualifiedArrayType.
920	inline QualType getUnqualifiedType() const;
921
922	/// Retrieve the unqualified variant of the given type, removing as little
923	/// sugar as possible.
924	///
925	/// Like getUnqualifiedType(), but also returns the set of
926	/// qualifiers that were built up.
927	///
928	/// The resulting type might still be qualified if it's sugar for an array
929	/// type. To strip qualifiers even from within a sugared array type, use
930	/// ASTContext::getUnqualifiedArrayType.
931	inline SplitQualType getSplitUnqualifiedType() const;
932
933	/// Determine whether this type is more qualified than the other
934	/// given type, requiring exact equality for non-CVR qualifiers.
935	bool isMoreQualifiedThan(QualType Other) const;
936
937	/// Determine whether this type is at least as qualified as the other
938	/// given type, requiring exact equality for non-CVR qualifiers.
939	bool isAtLeastAsQualifiedAs(QualType Other) const;
940
941	QualType getNonReferenceType() const;
942
943	/// Determine the type of a (typically non-lvalue) expression with the
944	/// specified result type.
945	///
946	/// This routine should be used for expressions for which the return type is
947	/// explicitly specified (e.g., in a cast or call) and isn't necessarily
948	/// an lvalue. It removes a top-level reference (since there are no
949	/// expressions of reference type) and deletes top-level cvr-qualifiers
950	/// from non-class types (in C++) or all types (in C).
951	QualType getNonLValueExprType(const ASTContext &Context) const;
952
953	/// Remove an outer pack expansion type (if any) from this type. Used as part
954	/// of converting the type of a declaration to the type of an expression that
955	/// references that expression. It's meaningless for an expression to have a
956	/// pack expansion type.
957	QualType getNonPackExpansionType() const;
958
959	/// Return the specified type with any "sugar" removed from
960	/// the type. This takes off typedefs, typeof's etc. If the outer level of
961	/// the type is already concrete, it returns it unmodified. This is similar
962	/// to getting the canonical type, but it doesn't remove all typedefs. For
963	/// example, it returns "T" as "T", (not as "int*"), because the pointer is
964	/// concrete.
965	///
966	/// Qualifiers are left in place.
967	QualType getDesugaredType(const ASTContext &Context) const {
968	return getDesugaredType(*this, Context);
969	}
970
971	SplitQualType getSplitDesugaredType() const {
972	return getSplitDesugaredType(*this);
973	}
974
975	/// Return the specified type with one level of "sugar" removed from
976	/// the type.
977	///
978	/// This routine takes off the first typedef, typeof, etc. If the outer level
979	/// of the type is already concrete, it returns it unmodified.
980	QualType getSingleStepDesugaredType(const ASTContext &Context) const {
981	return getSingleStepDesugaredTypeImpl(*this, Context);
982	}
983
984	/// Returns the specified type after dropping any
985	/// outer-level parentheses.
986	QualType IgnoreParens() const {
987	if (isa<ParenType>(*this))
988	return QualType::IgnoreParens(*this);
989	return *this;
990	}
991
992	/// Indicate whether the specified types and qualifiers are identical.
993	friend bool operator==(const QualType &LHS, const QualType &RHS) {
994	return LHS.Value == RHS.Value;
995	}
996	friend bool operator!=(const QualType &LHS, const QualType &RHS) {
997	return LHS.Value != RHS.Value;
998	}
999	friend bool operator<(const QualType &LHS, const QualType &RHS) {
1000	return LHS.Value < RHS.Value;
1001	}
1002
1003	static std::string getAsString(SplitQualType split,
1004	const PrintingPolicy &Policy) {
1005	return getAsString(split.Ty, split.Quals, Policy);
1006	}
1007	static std::string getAsString(const Type *ty, Qualifiers qs,
1008	const PrintingPolicy &Policy);
1009
1010	std::string getAsString() const;
1011	std::string getAsString(const PrintingPolicy &Policy) const;
1012
1013	void print(raw_ostream &OS, const PrintingPolicy &Policy,
1014	const Twine &PlaceHolder = Twine(),
1015	unsigned Indentation = 0) const;
1016
1017	static void print(SplitQualType split, raw_ostream &OS,
1018	const PrintingPolicy &policy, const Twine &PlaceHolder,
1019	unsigned Indentation = 0) {
1020	return print(split.Ty, split.Quals, OS, policy, PlaceHolder, Indentation);
1021	}
1022
1023	static void print(const Type *ty, Qualifiers qs,
1024	raw_ostream &OS, const PrintingPolicy &policy,
1025	const Twine &PlaceHolder,
1026	unsigned Indentation = 0);
1027
1028	void getAsStringInternal(std::string &Str,
1029	const PrintingPolicy &Policy) const;
1030
1031	static void getAsStringInternal(SplitQualType split, std::string &out,
1032	const PrintingPolicy &policy) {
1033	return getAsStringInternal(split.Ty, split.Quals, out, policy);
1034	}
1035
1036	static void getAsStringInternal(const Type *ty, Qualifiers qs,
1037	std::string &out,
1038	const PrintingPolicy &policy);
1039
1040	class StreamedQualTypeHelper {
1041	const QualType &T;
1042	const PrintingPolicy &Policy;
1043	const Twine &PlaceHolder;
1044	unsigned Indentation;
1045
1046	public:
1047	StreamedQualTypeHelper(const QualType &T, const PrintingPolicy &Policy,
1048	const Twine &PlaceHolder, unsigned Indentation)
1049	: T(T), Policy(Policy), PlaceHolder(PlaceHolder),
1050	Indentation(Indentation) {}
1051
1052	friend raw_ostream &operator<<(raw_ostream &OS,
1053	const StreamedQualTypeHelper &SQT) {
1054	SQT.T.print(OS, SQT.Policy, SQT.PlaceHolder, SQT.Indentation);
1055	return OS;
1056	}
1057	};
1058
1059	StreamedQualTypeHelper stream(const PrintingPolicy &Policy,
1060	const Twine &PlaceHolder = Twine(),
1061	unsigned Indentation = 0) const {
1062	return StreamedQualTypeHelper(*this, Policy, PlaceHolder, Indentation);
1063	}
1064
1065	void dump(const char *s) const;
1066	void dump() const;
1067	void dump(llvm::raw_ostream &OS, const ASTContext &Context) const;
1068
1069	void Profile(llvm::FoldingSetNodeID &ID) const {
1070	ID.AddPointer(getAsOpaquePtr());
1071	}
1072
1073	/// Check if this type has any address space qualifier.
1074	inline bool hasAddressSpace() const;
1075
1076	/// Return the address space of this type.
1077	inline LangAS getAddressSpace() const;
1078
1079	/// Returns true if address space qualifiers overlap with T address space
1080	/// qualifiers.
1081	/// OpenCL C defines conversion rules for pointers to different address spaces
1082	/// and notion of overlapping address spaces.
1083	/// CL1.1 or CL1.2:
1084	/// address spaces overlap iff they are they same.
1085	/// OpenCL C v2.0 s6.5.5 adds:
1086	/// __generic overlaps with any address space except for __constant.
1087	bool isAddressSpaceOverlapping(QualType T) const {
1088	Qualifiers Q = getQualifiers();
1089	Qualifiers TQ = T.getQualifiers();
1090	// Address spaces overlap if at least one of them is a superset of another
1091	return Q.isAddressSpaceSupersetOf(TQ) \|\| TQ.isAddressSpaceSupersetOf(Q);
1092	}
1093
1094	/// Returns gc attribute of this type.
1095	inline Qualifiers::GC getObjCGCAttr() const;
1096
1097	/// true when Type is objc's weak.
1098	bool isObjCGCWeak() const {
1099	return getObjCGCAttr() == Qualifiers::Weak;
1100	}
1101
1102	/// true when Type is objc's strong.
1103	bool isObjCGCStrong() const {
1104	return getObjCGCAttr() == Qualifiers::Strong;
1105	}
1106
1107	/// Returns lifetime attribute of this type.
1108	Qualifiers::ObjCLifetime getObjCLifetime() const {
1109	return getQualifiers().getObjCLifetime();
1110	}
1111
1112	bool hasNonTrivialObjCLifetime() const {
1113	return getQualifiers().hasNonTrivialObjCLifetime();
1114	}
1115
1116	bool hasStrongOrWeakObjCLifetime() const {
1117	return getQualifiers().hasStrongOrWeakObjCLifetime();
1118	}
1119
1120	// true when Type is objc's weak and weak is enabled but ARC isn't.
1121	bool isNonWeakInMRRWithObjCWeak(const ASTContext &Context) const;
1122
1123	enum PrimitiveDefaultInitializeKind {
1124	/// The type does not fall into any of the following categories. Note that
1125	/// this case is zero-valued so that values of this enum can be used as a
1126	/// boolean condition for non-triviality.
1127	PDIK_Trivial,
1128
1129	/// The type is an Objective-C retainable pointer type that is qualified
1130	/// with the ARC __strong qualifier.
1131	PDIK_ARCStrong,
1132
1133	/// The type is an Objective-C retainable pointer type that is qualified
1134	/// with the ARC __weak qualifier.
1135	PDIK_ARCWeak,
1136
1137	/// The type is a struct containing a field whose type is not PCK_Trivial.
1138	PDIK_Struct
1139	};
1140
1141	/// Functions to query basic properties of non-trivial C struct types.
1142
1143	/// Check if this is a non-trivial type that would cause a C struct
1144	/// transitively containing this type to be non-trivial to default initialize
1145	/// and return the kind.
1146	PrimitiveDefaultInitializeKind
1147	isNonTrivialToPrimitiveDefaultInitialize() const;
1148
1149	enum PrimitiveCopyKind {
1150	/// The type does not fall into any of the following categories. Note that
1151	/// this case is zero-valued so that values of this enum can be used as a
1152	/// boolean condition for non-triviality.
1153	PCK_Trivial,
1154
1155	/// The type would be trivial except that it is volatile-qualified. Types
1156	/// that fall into one of the other non-trivial cases may additionally be
1157	/// volatile-qualified.
1158	PCK_VolatileTrivial,
1159
1160	/// The type is an Objective-C retainable pointer type that is qualified
1161	/// with the ARC __strong qualifier.
1162	PCK_ARCStrong,
1163
1164	/// The type is an Objective-C retainable pointer type that is qualified
1165	/// with the ARC __weak qualifier.
1166	PCK_ARCWeak,
1167
1168	/// The type is a struct containing a field whose type is neither
1169	/// PCK_Trivial nor PCK_VolatileTrivial.
1170	/// Note that a C++ struct type does not necessarily match this; C++ copying
1171	/// semantics are too complex to express here, in part because they depend
1172	/// on the exact constructor or assignment operator that is chosen by
1173	/// overload resolution to do the copy.
1174	PCK_Struct
1175	};
1176
1177	/// Check if this is a non-trivial type that would cause a C struct
1178	/// transitively containing this type to be non-trivial to copy and return the
1179	/// kind.
1180	PrimitiveCopyKind isNonTrivialToPrimitiveCopy() const;
1181
1182	/// Check if this is a non-trivial type that would cause a C struct
1183	/// transitively containing this type to be non-trivial to destructively
1184	/// move and return the kind. Destructive move in this context is a C++-style
1185	/// move in which the source object is placed in a valid but unspecified state
1186	/// after it is moved, as opposed to a truly destructive move in which the
1187	/// source object is placed in an uninitialized state.
1188	PrimitiveCopyKind isNonTrivialToPrimitiveDestructiveMove() const;
1189
1190	enum DestructionKind {
1191	DK_none,
1192	DK_cxx_destructor,
1193	DK_objc_strong_lifetime,
1194	DK_objc_weak_lifetime,
1195	DK_nontrivial_c_struct
1196	};
1197
1198	/// Returns a nonzero value if objects of this type require
1199	/// non-trivial work to clean up after. Non-zero because it's
1200	/// conceivable that qualifiers (objc_gc(weak)?) could make
1201	/// something require destruction.
1202	DestructionKind isDestructedType() const {
1203	return isDestructedTypeImpl(*this);
1204	}
1205
1206	/// Check if this is or contains a C union that is non-trivial to
1207	/// default-initialize, which is a union that has a member that is non-trivial
1208	/// to default-initialize. If this returns true,
1209	/// isNonTrivialToPrimitiveDefaultInitialize returns PDIK_Struct.
1210	bool hasNonTrivialToPrimitiveDefaultInitializeCUnion() const;
1211
1212	/// Check if this is or contains a C union that is non-trivial to destruct,
1213	/// which is a union that has a member that is non-trivial to destruct. If
1214	/// this returns true, isDestructedType returns DK_nontrivial_c_struct.
1215	bool hasNonTrivialToPrimitiveDestructCUnion() const;
1216
1217	/// Check if this is or contains a C union that is non-trivial to copy, which
1218	/// is a union that has a member that is non-trivial to copy. If this returns
1219	/// true, isNonTrivialToPrimitiveCopy returns PCK_Struct.
1220	bool hasNonTrivialToPrimitiveCopyCUnion() const;
1221
1222	/// Determine whether expressions of the given type are forbidden
1223	/// from being lvalues in C.
1224	///
1225	/// The expression types that are forbidden to be lvalues are:
1226	/// - 'void', but not qualified void
1227	/// - function types
1228	///
1229	/// The exact rule here is C99 6.3.2.1:
1230	/// An lvalue is an expression with an object type or an incomplete
1231	/// type other than void.
1232	bool isCForbiddenLValueType() const;
1233
1234	/// Substitute type arguments for the Objective-C type parameters used in the
1235	/// subject type.
1236	///
1237	/// \param ctx ASTContext in which the type exists.
1238	///
1239	/// \param typeArgs The type arguments that will be substituted for the
1240	/// Objective-C type parameters in the subject type, which are generally
1241	/// computed via \c Type::getObjCSubstitutions. If empty, the type
1242	/// parameters will be replaced with their bounds or id/Class, as appropriate
1243	/// for the context.
1244	///
1245	/// \param context The context in which the subject type was written.
1246	///
1247	/// \returns the resulting type.
1248	QualType substObjCTypeArgs(ASTContext &ctx,
1249	ArrayRef<QualType> typeArgs,
1250	ObjCSubstitutionContext context) const;
1251
1252	/// Substitute type arguments from an object type for the Objective-C type
1253	/// parameters used in the subject type.
1254	///
1255	/// This operation combines the computation of type arguments for
1256	/// substitution (\c Type::getObjCSubstitutions) with the actual process of
1257	/// substitution (\c QualType::substObjCTypeArgs) for the convenience of
1258	/// callers that need to perform a single substitution in isolation.
1259	///
1260	/// \param objectType The type of the object whose member type we're
1261	/// substituting into. For example, this might be the receiver of a message
1262	/// or the base of a property access.
1263	///
1264	/// \param dc The declaration context from which the subject type was
1265	/// retrieved, which indicates (for example) which type parameters should
1266	/// be substituted.
1267	///
1268	/// \param context The context in which the subject type was written.
1269	///
1270	/// \returns the subject type after replacing all of the Objective-C type
1271	/// parameters with their corresponding arguments.
1272	QualType substObjCMemberType(QualType objectType,
1273	const DeclContext *dc,
1274	ObjCSubstitutionContext context) const;
1275
1276	/// Strip Objective-C "__kindof" types from the given type.
1277	QualType stripObjCKindOfType(const ASTContext &ctx) const;
1278
1279	/// Remove all qualifiers including _Atomic.
1280	QualType getAtomicUnqualifiedType() const;
1281
1282	private:
1283	// These methods are implemented in a separate translation unit;
1284	// "static"-ize them to avoid creating temporary QualTypes in the
1285	// caller.
1286	static bool isConstant(QualType T, const ASTContext& Ctx);
1287	static QualType getDesugaredType(QualType T, const ASTContext &Context);
1288	static SplitQualType getSplitDesugaredType(QualType T);
1289	static SplitQualType getSplitUnqualifiedTypeImpl(QualType type);
1290	static QualType getSingleStepDesugaredTypeImpl(QualType type,
1291	const ASTContext &C);
1292	static QualType IgnoreParens(QualType T);
1293	static DestructionKind isDestructedTypeImpl(QualType type);
1294
1295	/// Check if \param RD is or contains a non-trivial C union.
1296	static bool hasNonTrivialToPrimitiveDefaultInitializeCUnion(const RecordDecl *RD);
1297	static bool hasNonTrivialToPrimitiveDestructCUnion(const RecordDecl *RD);
1298	static bool hasNonTrivialToPrimitiveCopyCUnion(const RecordDecl *RD);
1299	};
1300
1301	} // namespace clang
1302
1303	namespace llvm {
1304
1305	/// Implement simplify_type for QualType, so that we can dyn_cast from QualType
1306	/// to a specific Type class.
1307	template<> struct simplify_type< ::clang::QualType> {
1308	using SimpleType = const ::clang::Type *;
1309
1310	static SimpleType getSimplifiedValue(::clang::QualType Val) {
1311	return Val.getTypePtr();
1312	}
1313	};
1314
1315	// Teach SmallPtrSet that QualType is "basically a pointer".
1316	template<>
1317	struct PointerLikeTypeTraits<clang::QualType> {
1318	static inline void *getAsVoidPointer(clang::QualType P) {
1319	return P.getAsOpaquePtr();
1320	}
1321
1322	static inline clang::QualType getFromVoidPointer(void *P) {
1323	return clang::QualType::getFromOpaquePtr(P);
1324	}
1325
1326	// Various qualifiers go in low bits.
1327	static constexpr int NumLowBitsAvailable = 0;
1328	};
1329
1330	} // namespace llvm
1331
1332	namespace clang {
1333
1334	/// Base class that is common to both the \c ExtQuals and \c Type
1335	/// classes, which allows \c QualType to access the common fields between the
1336	/// two.
1337	class ExtQualsTypeCommonBase {
1338	friend class ExtQuals;
1339	friend class QualType;
1340	friend class Type;
1341
1342	/// The "base" type of an extended qualifiers type (\c ExtQuals) or
1343	/// a self-referential pointer (for \c Type).
1344	///
1345	/// This pointer allows an efficient mapping from a QualType to its
1346	/// underlying type pointer.
1347	const Type *const BaseType;
1348
1349	/// The canonical type of this type. A QualType.
1350	QualType CanonicalType;
1351
1352	ExtQualsTypeCommonBase(const Type *baseType, QualType canon)
1353	: BaseType(baseType), CanonicalType(canon) {}
1354	};
1355
1356	/// We can encode up to four bits in the low bits of a
1357	/// type pointer, but there are many more type qualifiers that we want
1358	/// to be able to apply to an arbitrary type. Therefore we have this
1359	/// struct, intended to be heap-allocated and used by QualType to
1360	/// store qualifiers.
1361	///
1362	/// The current design tags the 'const', 'restrict', and 'volatile' qualifiers
1363	/// in three low bits on the QualType pointer; a fourth bit records whether
1364	/// the pointer is an ExtQuals node. The extended qualifiers (address spaces,
1365	/// Objective-C GC attributes) are much more rare.
1366	class ExtQuals : public ExtQualsTypeCommonBase, public llvm::FoldingSetNode {
1367	// NOTE: changing the fast qualifiers should be straightforward as
1368	// long as you don't make 'const' non-fast.
1369	// 1. Qualifiers:
1370	// a) Modify the bitmasks (Qualifiers::TQ and DeclSpec::TQ).
1371	// Fast qualifiers must occupy the low-order bits.
1372	// b) Update Qualifiers::FastWidth and FastMask.
1373	// 2. QualType:
1374	// a) Update is{Volatile,Restrict}Qualified(), defined inline.
1375	// b) Update remove{Volatile,Restrict}, defined near the end of
1376	// this header.
1377	// 3. ASTContext:
1378	// a) Update get{Volatile,Restrict}Type.
1379
1380	/// The immutable set of qualifiers applied by this node. Always contains
1381	/// extended qualifiers.
1382	Qualifiers Quals;
1383
1384	ExtQuals *this_() { return this; }
1385
1386	public:
1387	ExtQuals(const Type *baseType, QualType canon, Qualifiers quals)
1388	: ExtQualsTypeCommonBase(baseType,
1389	canon.isNull() ? QualType(this_(), 0) : canon),
1390	Quals(quals) {
1391	assert(Quals.hasNonFastQualifiers()((Quals.hasNonFastQualifiers() && "ExtQuals created with no fast qualifiers" ) ? static_cast<void> (0) : __assert_fail ("Quals.hasNonFastQualifiers() && \"ExtQuals created with no fast qualifiers\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 1392, __PRETTY_FUNCTION__))
1392	&& "ExtQuals created with no fast qualifiers")((Quals.hasNonFastQualifiers() && "ExtQuals created with no fast qualifiers" ) ? static_cast<void> (0) : __assert_fail ("Quals.hasNonFastQualifiers() && \"ExtQuals created with no fast qualifiers\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 1392, __PRETTY_FUNCTION__));
1393	assert(!Quals.hasFastQualifiers()((!Quals.hasFastQualifiers() && "ExtQuals created with fast qualifiers" ) ? static_cast<void> (0) : __assert_fail ("!Quals.hasFastQualifiers() && \"ExtQuals created with fast qualifiers\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 1394, __PRETTY_FUNCTION__))
1394	&& "ExtQuals created with fast qualifiers")((!Quals.hasFastQualifiers() && "ExtQuals created with fast qualifiers" ) ? static_cast<void> (0) : __assert_fail ("!Quals.hasFastQualifiers() && \"ExtQuals created with fast qualifiers\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 1394, __PRETTY_FUNCTION__));
1395	}
1396
1397	Qualifiers getQualifiers() const { return Quals; }
1398
1399	bool hasObjCGCAttr() const { return Quals.hasObjCGCAttr(); }
1400	Qualifiers::GC getObjCGCAttr() const { return Quals.getObjCGCAttr(); }
1401
1402	bool hasObjCLifetime() const { return Quals.hasObjCLifetime(); }
1403	Qualifiers::ObjCLifetime getObjCLifetime() const {
1404	return Quals.getObjCLifetime();
1405	}
1406
1407	bool hasAddressSpace() const { return Quals.hasAddressSpace(); }
1408	LangAS getAddressSpace() const { return Quals.getAddressSpace(); }
1409
1410	const Type *getBaseType() const { return BaseType; }
1411
1412	public:
1413	void Profile(llvm::FoldingSetNodeID &ID) const {
1414	Profile(ID, getBaseType(), Quals);
1415	}
1416
1417	static void Profile(llvm::FoldingSetNodeID &ID,
1418	const Type *BaseType,
1419	Qualifiers Quals) {
1420	assert(!Quals.hasFastQualifiers() && "fast qualifiers in ExtQuals hash!")((!Quals.hasFastQualifiers() && "fast qualifiers in ExtQuals hash!" ) ? static_cast<void> (0) : __assert_fail ("!Quals.hasFastQualifiers() && \"fast qualifiers in ExtQuals hash!\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 1420, __PRETTY_FUNCTION__));
1421	ID.AddPointer(BaseType);
1422	Quals.Profile(ID);
1423	}
1424	};
1425
1426	/// The kind of C++11 ref-qualifier associated with a function type.
1427	/// This determines whether a member function's "this" object can be an
1428	/// lvalue, rvalue, or neither.
1429	enum RefQualifierKind {
1430	/// No ref-qualifier was provided.
1431	RQ_None = 0,
1432
1433	/// An lvalue ref-qualifier was provided (\c &).
1434	RQ_LValue,
1435
1436	/// An rvalue ref-qualifier was provided (\c &&).
1437	RQ_RValue
1438	};
1439
1440	/// Which keyword(s) were used to create an AutoType.
1441	enum class AutoTypeKeyword {
1442	/// auto
1443	Auto,
1444
1445	/// decltype(auto)
1446	DecltypeAuto,
1447
1448	/// __auto_type (GNU extension)
1449	GNUAutoType
1450	};
1451
1452	/// The base class of the type hierarchy.
1453	///
1454	/// A central concept with types is that each type always has a canonical
1455	/// type. A canonical type is the type with any typedef names stripped out
1456	/// of it or the types it references. For example, consider:
1457	///
1458	/// typedef int foo;
1459	/// typedef foo* bar;
1460	/// 'int ' 'foo ' 'bar'
1461	///
1462	/// There will be a Type object created for 'int'. Since int is canonical, its
1463	/// CanonicalType pointer points to itself. There is also a Type for 'foo' (a
1464	/// TypedefType). Its CanonicalType pointer points to the 'int' Type. Next
1465	/// there is a PointerType that represents 'int*', which, like 'int', is
1466	/// canonical. Finally, there is a PointerType type for 'foo*' whose canonical
1467	/// type is 'int*', and there is a TypedefType for 'bar', whose canonical type
1468	/// is also 'int*'.
1469	///
1470	/// Non-canonical types are useful for emitting diagnostics, without losing
1471	/// information about typedefs being used. Canonical types are useful for type
1472	/// comparisons (they allow by-pointer equality tests) and useful for reasoning
1473	/// about whether something has a particular form (e.g. is a function type),
1474	/// because they implicitly, recursively, strip all typedefs out of a type.
1475	///
1476	/// Types, once created, are immutable.
1477	///
1478	class alignas(8) Type : public ExtQualsTypeCommonBase {
1479	public:
1480	enum TypeClass {
1481	#define TYPE(Class, Base) Class,
1482	#define LAST_TYPE(Class) TypeLast = Class
1483	#define ABSTRACT_TYPE(Class, Base)
1484	#include "clang/AST/TypeNodes.inc"
1485	};
1486
1487	private:
1488	/// Bitfields required by the Type class.
1489	class TypeBitfields {
1490	friend class Type;
1491	template <class T> friend class TypePropertyCache;
1492
1493	/// TypeClass bitfield - Enum that specifies what subclass this belongs to.
1494	unsigned TC : 8;
1495
1496	/// Store information on the type dependency.
1497	unsigned Dependence : llvm::BitWidth<TypeDependence>;
1498
1499	/// True if the cache (i.e. the bitfields here starting with
1500	/// 'Cache') is valid.
1501	mutable unsigned CacheValid : 1;
1502
1503	/// Linkage of this type.
1504	mutable unsigned CachedLinkage : 3;
1505
1506	/// Whether this type involves and local or unnamed types.
1507	mutable unsigned CachedLocalOrUnnamed : 1;
1508
1509	/// Whether this type comes from an AST file.
1510	mutable unsigned FromAST : 1;
1511
1512	bool isCacheValid() const {
1513	return CacheValid;
1514	}
1515
1516	Linkage getLinkage() const {
1517	assert(isCacheValid() && "getting linkage from invalid cache")((isCacheValid() && "getting linkage from invalid cache" ) ? static_cast<void> (0) : __assert_fail ("isCacheValid() && \"getting linkage from invalid cache\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 1517, __PRETTY_FUNCTION__));
1518	return static_cast<Linkage>(CachedLinkage);
1519	}
1520
1521	bool hasLocalOrUnnamedType() const {
1522	assert(isCacheValid() && "getting linkage from invalid cache")((isCacheValid() && "getting linkage from invalid cache" ) ? static_cast<void> (0) : __assert_fail ("isCacheValid() && \"getting linkage from invalid cache\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 1522, __PRETTY_FUNCTION__));
1523	return CachedLocalOrUnnamed;
1524	}
1525	};
1526	enum { NumTypeBits = 8 + llvm::BitWidth<TypeDependence> + 6 };
1527
1528	protected:
1529	// These classes allow subclasses to somewhat cleanly pack bitfields
1530	// into Type.
1531
1532	class ArrayTypeBitfields {
1533	friend class ArrayType;
1534
1535	unsigned : NumTypeBits;
1536
1537	/// CVR qualifiers from declarations like
1538	/// 'int X[static restrict 4]'. For function parameters only.
1539	unsigned IndexTypeQuals : 3;
1540
1541	/// Storage class qualifiers from declarations like
1542	/// 'int X[static restrict 4]'. For function parameters only.
1543	/// Actually an ArrayType::ArraySizeModifier.
1544	unsigned SizeModifier : 3;
1545	};
1546
1547	class ConstantArrayTypeBitfields {
1548	friend class ConstantArrayType;
1549
1550	unsigned : NumTypeBits + 3 + 3;
1551
1552	/// Whether we have a stored size expression.
1553	unsigned HasStoredSizeExpr : 1;
1554	};
1555
1556	class BuiltinTypeBitfields {
1557	friend class BuiltinType;
1558
1559	unsigned : NumTypeBits;
1560
1561	/// The kind (BuiltinType::Kind) of builtin type this is.
1562	unsigned Kind : 8;
1563	};
1564
1565	/// FunctionTypeBitfields store various bits belonging to FunctionProtoType.
1566	/// Only common bits are stored here. Additional uncommon bits are stored
1567	/// in a trailing object after FunctionProtoType.
1568	class FunctionTypeBitfields {
1569	friend class FunctionProtoType;
1570	friend class FunctionType;
1571
1572	unsigned : NumTypeBits;
1573
1574	/// Extra information which affects how the function is called, like
1575	/// regparm and the calling convention.
1576	unsigned ExtInfo : 13;
1577
1578	/// The ref-qualifier associated with a \c FunctionProtoType.
1579	///
1580	/// This is a value of type \c RefQualifierKind.
1581	unsigned RefQualifier : 2;
1582
1583	/// Used only by FunctionProtoType, put here to pack with the
1584	/// other bitfields.
1585	/// The qualifiers are part of FunctionProtoType because...
1586	///
1587	/// C++ 8.3.5p4: The return type, the parameter type list and the
1588	/// cv-qualifier-seq, [...], are part of the function type.
1589	unsigned FastTypeQuals : Qualifiers::FastWidth;
1590	/// Whether this function has extended Qualifiers.
1591	unsigned HasExtQuals : 1;
1592
1593	/// The number of parameters this function has, not counting '...'.
1594	/// According to [implimits] 8 bits should be enough here but this is
1595	/// somewhat easy to exceed with metaprogramming and so we would like to
1596	/// keep NumParams as wide as reasonably possible.
1597	unsigned NumParams : 16;
1598
1599	/// The type of exception specification this function has.
1600	unsigned ExceptionSpecType : 4;
1601
1602	/// Whether this function has extended parameter information.
1603	unsigned HasExtParameterInfos : 1;
1604
1605	/// Whether the function is variadic.
1606	unsigned Variadic : 1;
1607
1608	/// Whether this function has a trailing return type.
1609	unsigned HasTrailingReturn : 1;
1610	};
1611
1612	class ObjCObjectTypeBitfields {
1613	friend class ObjCObjectType;
1614
1615	unsigned : NumTypeBits;
1616
1617	/// The number of type arguments stored directly on this object type.
1618	unsigned NumTypeArgs : 7;
1619
1620	/// The number of protocols stored directly on this object type.
1621	unsigned NumProtocols : 6;
1622
1623	/// Whether this is a "kindof" type.
1624	unsigned IsKindOf : 1;
1625	};
1626
1627	class ReferenceTypeBitfields {
1628	friend class ReferenceType;
1629
1630	unsigned : NumTypeBits;
1631
1632	/// True if the type was originally spelled with an lvalue sigil.
1633	/// This is never true of rvalue references but can also be false
1634	/// on lvalue references because of C++0x [dcl.typedef]p9,
1635	/// as follows:
1636	///
1637	/// typedef int &ref; // lvalue, spelled lvalue
1638	/// typedef int &&rvref; // rvalue
1639	/// ref &a; // lvalue, inner ref, spelled lvalue
1640	/// ref &&a; // lvalue, inner ref
1641	/// rvref &a; // lvalue, inner ref, spelled lvalue
1642	/// rvref &&a; // rvalue, inner ref
1643	unsigned SpelledAsLValue : 1;
1644
1645	/// True if the inner type is a reference type. This only happens
1646	/// in non-canonical forms.
1647	unsigned InnerRef : 1;
1648	};
1649
1650	class TypeWithKeywordBitfields {
1651	friend class TypeWithKeyword;
1652
1653	unsigned : NumTypeBits;
1654
1655	/// An ElaboratedTypeKeyword. 8 bits for efficient access.
1656	unsigned Keyword : 8;
1657	};
1658
1659	enum { NumTypeWithKeywordBits = 8 };
1660
1661	class ElaboratedTypeBitfields {
1662	friend class ElaboratedType;
1663
1664	unsigned : NumTypeBits;
1665	unsigned : NumTypeWithKeywordBits;
1666
1667	/// Whether the ElaboratedType has a trailing OwnedTagDecl.
1668	unsigned HasOwnedTagDecl : 1;
1669	};
1670
1671	class VectorTypeBitfields {
1672	friend class VectorType;
1673	friend class DependentVectorType;
1674
1675	unsigned : NumTypeBits;
1676
1677	/// The kind of vector, either a generic vector type or some
1678	/// target-specific vector type such as for AltiVec or Neon.
1679	unsigned VecKind : 3;
1680	/// The number of elements in the vector.
1681	uint32_t NumElements;
1682	};
1683
1684	class AttributedTypeBitfields {
1685	friend class AttributedType;
1686
1687	unsigned : NumTypeBits;
1688
1689	/// An AttributedType::Kind
1690	unsigned AttrKind : 32 - NumTypeBits;
1691	};
1692
1693	class AutoTypeBitfields {
1694	friend class AutoType;
1695
1696	unsigned : NumTypeBits;
1697
1698	/// Was this placeholder type spelled as 'auto', 'decltype(auto)',
1699	/// or '__auto_type'? AutoTypeKeyword value.
1700	unsigned Keyword : 2;
1701
1702	/// The number of template arguments in the type-constraints, which is
1703	/// expected to be able to hold at least 1024 according to [implimits].
1704	/// However as this limit is somewhat easy to hit with template
1705	/// metaprogramming we'd prefer to keep it as large as possible.
1706	/// At the moment it has been left as a non-bitfield since this type
1707	/// safely fits in 64 bits as an unsigned, so there is no reason to
1708	/// introduce the performance impact of a bitfield.
1709	unsigned NumArgs;
1710	};
1711
1712	class SubstTemplateTypeParmPackTypeBitfields {
1713	friend class SubstTemplateTypeParmPackType;
1714
1715	unsigned : NumTypeBits;
1716
1717	/// The number of template arguments in \c Arguments, which is
1718	/// expected to be able to hold at least 1024 according to [implimits].
1719	/// However as this limit is somewhat easy to hit with template
1720	/// metaprogramming we'd prefer to keep it as large as possible.
1721	/// At the moment it has been left as a non-bitfield since this type
1722	/// safely fits in 64 bits as an unsigned, so there is no reason to
1723	/// introduce the performance impact of a bitfield.
1724	unsigned NumArgs;
1725	};
1726
1727	class TemplateSpecializationTypeBitfields {
1728	friend class TemplateSpecializationType;
1729
1730	unsigned : NumTypeBits;
1731
1732	/// Whether this template specialization type is a substituted type alias.
1733	unsigned TypeAlias : 1;
1734
1735	/// The number of template arguments named in this class template
1736	/// specialization, which is expected to be able to hold at least 1024
1737	/// according to [implimits]. However, as this limit is somewhat easy to
1738	/// hit with template metaprogramming we'd prefer to keep it as large
1739	/// as possible. At the moment it has been left as a non-bitfield since
1740	/// this type safely fits in 64 bits as an unsigned, so there is no reason
1741	/// to introduce the performance impact of a bitfield.
1742	unsigned NumArgs;
1743	};
1744
1745	class DependentTemplateSpecializationTypeBitfields {
1746	friend class DependentTemplateSpecializationType;
1747
1748	unsigned : NumTypeBits;
1749	unsigned : NumTypeWithKeywordBits;
1750
1751	/// The number of template arguments named in this class template
1752	/// specialization, which is expected to be able to hold at least 1024
1753	/// according to [implimits]. However, as this limit is somewhat easy to
1754	/// hit with template metaprogramming we'd prefer to keep it as large
1755	/// as possible. At the moment it has been left as a non-bitfield since
1756	/// this type safely fits in 64 bits as an unsigned, so there is no reason
1757	/// to introduce the performance impact of a bitfield.
1758	unsigned NumArgs;
1759	};
1760
1761	class PackExpansionTypeBitfields {
1762	friend class PackExpansionType;
1763
1764	unsigned : NumTypeBits;
1765
1766	/// The number of expansions that this pack expansion will
1767	/// generate when substituted (+1), which is expected to be able to
1768	/// hold at least 1024 according to [implimits]. However, as this limit
1769	/// is somewhat easy to hit with template metaprogramming we'd prefer to
1770	/// keep it as large as possible. At the moment it has been left as a
1771	/// non-bitfield since this type safely fits in 64 bits as an unsigned, so
1772	/// there is no reason to introduce the performance impact of a bitfield.
1773	///
1774	/// This field will only have a non-zero value when some of the parameter
1775	/// packs that occur within the pattern have been substituted but others
1776	/// have not.
1777	unsigned NumExpansions;
1778	};
1779
1780	union {
1781	TypeBitfields TypeBits;
1782	ArrayTypeBitfields ArrayTypeBits;
1783	ConstantArrayTypeBitfields ConstantArrayTypeBits;
1784	AttributedTypeBitfields AttributedTypeBits;
1785	AutoTypeBitfields AutoTypeBits;
1786	BuiltinTypeBitfields BuiltinTypeBits;
1787	FunctionTypeBitfields FunctionTypeBits;
1788	ObjCObjectTypeBitfields ObjCObjectTypeBits;
1789	ReferenceTypeBitfields ReferenceTypeBits;
1790	TypeWithKeywordBitfields TypeWithKeywordBits;
1791	ElaboratedTypeBitfields ElaboratedTypeBits;
1792	VectorTypeBitfields VectorTypeBits;
1793	SubstTemplateTypeParmPackTypeBitfields SubstTemplateTypeParmPackTypeBits;
1794	TemplateSpecializationTypeBitfields TemplateSpecializationTypeBits;
1795	DependentTemplateSpecializationTypeBitfields
1796	DependentTemplateSpecializationTypeBits;
1797	PackExpansionTypeBitfields PackExpansionTypeBits;
1798	};
1799
1800	private:
1801	template <class T> friend class TypePropertyCache;
1802
1803	/// Set whether this type comes from an AST file.
1804	void setFromAST(bool V = true) const {
1805	TypeBits.FromAST = V;
1806	}
1807
1808	protected:
1809	friend class ASTContext;
1810
1811	Type(TypeClass tc, QualType canon, TypeDependence Dependence)
1812	: ExtQualsTypeCommonBase(this,
1813	canon.isNull() ? QualType(this_(), 0) : canon) {
1814	static_assert(sizeof(*this) <= 8 + sizeof(ExtQualsTypeCommonBase),
1815	"changing bitfields changed sizeof(Type)!");
1816	static_assert(alignof(decltype(this)) % sizeof(void ) == 0,
1817	"Insufficient alignment!");
1818	TypeBits.TC = tc;
1819	TypeBits.Dependence = static_cast<unsigned>(Dependence);
1820	TypeBits.CacheValid = false;
1821	TypeBits.CachedLocalOrUnnamed = false;
1822	TypeBits.CachedLinkage = NoLinkage;
1823	TypeBits.FromAST = false;
1824	}
1825
1826	// silence VC++ warning C4355: 'this' : used in base member initializer list
1827	Type *this_() { return this; }
1828
1829	void setDependence(TypeDependence D) {
1830	TypeBits.Dependence = static_cast<unsigned>(D);
1831	}
1832
1833	void addDependence(TypeDependence D) { setDependence(getDependence() \| D); }
1834
1835	public:
1836	friend class ASTReader;
1837	friend class ASTWriter;
1838	template <class T> friend class serialization::AbstractTypeReader;
1839	template <class T> friend class serialization::AbstractTypeWriter;
1840
1841	Type(const Type &) = delete;
1842	Type(Type &&) = delete;
1843	Type &operator=(const Type &) = delete;
1844	Type &operator=(Type &&) = delete;
1845
1846	TypeClass getTypeClass() const { return static_cast<TypeClass>(TypeBits.TC); }
1847
1848	/// Whether this type comes from an AST file.
1849	bool isFromAST() const { return TypeBits.FromAST; }
1850
1851	/// Whether this type is or contains an unexpanded parameter
1852	/// pack, used to support C++0x variadic templates.
1853	///
1854	/// A type that contains a parameter pack shall be expanded by the
1855	/// ellipsis operator at some point. For example, the typedef in the
1856	/// following example contains an unexpanded parameter pack 'T':
1857	///
1858	/// \code
1859	/// template<typename ...T>
1860	/// struct X {
1861	/// typedef T* pointer_types; // ill-formed; T is a parameter pack.
1862	/// };
1863	/// \endcode
1864	///
1865	/// Note that this routine does not specify which
1866	bool containsUnexpandedParameterPack() const {
1867	return getDependence() & TypeDependence::UnexpandedPack;
1868	}
1869
1870	/// Determines if this type would be canonical if it had no further
1871	/// qualification.
1872	bool isCanonicalUnqualified() const {
1873	return CanonicalType == QualType(this, 0);
1874	}
1875
1876	/// Pull a single level of sugar off of this locally-unqualified type.
1877	/// Users should generally prefer SplitQualType::getSingleStepDesugaredType()
1878	/// or QualType::getSingleStepDesugaredType(const ASTContext&).
1879	QualType getLocallyUnqualifiedSingleStepDesugaredType() const;
1880
1881	/// As an extension, we classify types as one of "sized" or "sizeless";
1882	/// every type is one or the other. Standard types are all sized;
1883	/// sizeless types are purely an extension.
1884	///
1885	/// Sizeless types contain data with no specified size, alignment,
1886	/// or layout.
1887	bool isSizelessType() const;
1888	bool isSizelessBuiltinType() const;
1889
1890	/// Determines if this is a sizeless type supported by the
1891	/// 'arm_sve_vector_bits' type attribute, which can be applied to a single
1892	/// SVE vector or predicate, excluding tuple types such as svint32x4_t.
1893	bool isVLSTBuiltinType() const;
1894
1895	/// Returns the representative type for the element of an SVE builtin type.
1896	/// This is used to represent fixed-length SVE vectors created with the
1897	/// 'arm_sve_vector_bits' type attribute as VectorType.
1898	QualType getSveEltType(const ASTContext &Ctx) const;
1899
1900	/// Types are partitioned into 3 broad categories (C99 6.2.5p1):
1901	/// object types, function types, and incomplete types.
1902
1903	/// Return true if this is an incomplete type.
1904	/// A type that can describe objects, but which lacks information needed to
1905	/// determine its size (e.g. void, or a fwd declared struct). Clients of this
1906	/// routine will need to determine if the size is actually required.
1907	///
1908	/// Def If non-null, and the type refers to some kind of declaration
1909	/// that can be completed (such as a C struct, C++ class, or Objective-C
1910	/// class), will be set to the declaration.
1911	bool isIncompleteType(NamedDecl **Def = nullptr) const;
1912
1913	/// Return true if this is an incomplete or object
1914	/// type, in other words, not a function type.
1915	bool isIncompleteOrObjectType() const {
1916	return !isFunctionType();
1917	}
1918
1919	/// Determine whether this type is an object type.
1920	bool isObjectType() const {
1921	// C++ [basic.types]p8:
1922	// An object type is a (possibly cv-qualified) type that is not a
1923	// function type, not a reference type, and not a void type.
1924	return !isReferenceType() && !isFunctionType() && !isVoidType();
1925	}
1926
1927	/// Return true if this is a literal type
1928	/// (C++11 [basic.types]p10)
1929	bool isLiteralType(const ASTContext &Ctx) const;
1930
1931	/// Determine if this type is a structural type, per C++20 [temp.param]p7.
1932	bool isStructuralType() const;
1933
1934	/// Test if this type is a standard-layout type.
1935	/// (C++0x [basic.type]p9)
1936	bool isStandardLayoutType() const;
1937
1938	/// Helper methods to distinguish type categories. All type predicates
1939	/// operate on the canonical type, ignoring typedefs and qualifiers.
1940
1941	/// Returns true if the type is a builtin type.
1942	bool isBuiltinType() const;
1943
1944	/// Test for a particular builtin type.
1945	bool isSpecificBuiltinType(unsigned K) const;
1946
1947	/// Test for a type which does not represent an actual type-system type but
1948	/// is instead used as a placeholder for various convenient purposes within
1949	/// Clang. All such types are BuiltinTypes.
1950	bool isPlaceholderType() const;
1951	const BuiltinType *getAsPlaceholderType() const;
1952
1953	/// Test for a specific placeholder type.
1954	bool isSpecificPlaceholderType(unsigned K) const;
1955
1956	/// Test for a placeholder type other than Overload; see
1957	/// BuiltinType::isNonOverloadPlaceholderType.
1958	bool isNonOverloadPlaceholderType() const;
1959
1960	/// isIntegerType() does not include complex integers (a GCC extension).
1961	/// isComplexIntegerType() can be used to test for complex integers.
1962	bool isIntegerType() const; // C99 6.2.5p17 (int, char, bool, enum)
1963	bool isEnumeralType() const;
1964
1965	/// Determine whether this type is a scoped enumeration type.
1966	bool isScopedEnumeralType() const;
1967	bool isBooleanType() const;
1968	bool isCharType() const;
1969	bool isWideCharType() const;
1970	bool isChar8Type() const;
1971	bool isChar16Type() const;
1972	bool isChar32Type() const;
1973	bool isAnyCharacterType() const;
1974	bool isIntegralType(const ASTContext &Ctx) const;
1975
1976	/// Determine whether this type is an integral or enumeration type.
1977	bool isIntegralOrEnumerationType() const;
1978
1979	/// Determine whether this type is an integral or unscoped enumeration type.
1980	bool isIntegralOrUnscopedEnumerationType() const;
1981	bool isUnscopedEnumerationType() const;
1982
1983	/// Floating point categories.
1984	bool isRealFloatingType() const; // C99 6.2.5p10 (float, double, long double)
1985	/// isComplexType() does not include complex integers (a GCC extension).
1986	/// isComplexIntegerType() can be used to test for complex integers.
1987	bool isComplexType() const; // C99 6.2.5p11 (complex)
1988	bool isAnyComplexType() const; // C99 6.2.5p11 (complex) + Complex Int.
1989	bool isFloatingType() const; // C99 6.2.5p11 (real floating + complex)
1990	bool isHalfType() const; // OpenCL 6.1.1.1, NEON (IEEE 754-2008 half)
1991	bool isFloat16Type() const; // C11 extension ISO/IEC TS 18661
1992	bool isBFloat16Type() const;
1993	bool isFloat128Type() const;
1994	bool isRealType() const; // C99 6.2.5p17 (real floating + integer)
1995	bool isArithmeticType() const; // C99 6.2.5p18 (integer + floating)
1996	bool isVoidType() const; // C99 6.2.5p19
1997	bool isScalarType() const; // C99 6.2.5p21 (arithmetic + pointers)
1998	bool isAggregateType() const;
1999	bool isFundamentalType() const;
2000	bool isCompoundType() const;
2001
2002	// Type Predicates: Check to see if this type is structurally the specified
2003	// type, ignoring typedefs and qualifiers.
2004	bool isFunctionType() const;
2005	bool isFunctionNoProtoType() const { return getAs<FunctionNoProtoType>(); }
2006	bool isFunctionProtoType() const { return getAs<FunctionProtoType>(); }
2007	bool isPointerType() const;
2008	bool isAnyPointerType() const; // Any C pointer or ObjC object pointer
2009	bool isBlockPointerType() const;
2010	bool isVoidPointerType() const;
2011	bool isReferenceType() const;
2012	bool isLValueReferenceType() const;
2013	bool isRValueReferenceType() const;
2014	bool isObjectPointerType() const;
2015	bool isFunctionPointerType() const;
2016	bool isFunctionReferenceType() const;
2017	bool isMemberPointerType() const;
2018	bool isMemberFunctionPointerType() const;
2019	bool isMemberDataPointerType() const;
2020	bool isArrayType() const;
2021	bool isConstantArrayType() const;
2022	bool isIncompleteArrayType() const;
2023	bool isVariableArrayType() const;
2024	bool isDependentSizedArrayType() const;
2025	bool isRecordType() const;
2026	bool isClassType() const;
2027	bool isStructureType() const;
2028	bool isObjCBoxableRecordType() const;
2029	bool isInterfaceType() const;
2030	bool isStructureOrClassType() const;
2031	bool isUnionType() const;
2032	bool isComplexIntegerType() const; // GCC _Complex integer type.
2033	bool isVectorType() const; // GCC vector type.
2034	bool isExtVectorType() const; // Extended vector type.
2035	bool isMatrixType() const; // Matrix type.
2036	bool isConstantMatrixType() const; // Constant matrix type.
2037	bool isDependentAddressSpaceType() const; // value-dependent address space qualifier
2038	bool isObjCObjectPointerType() const; // pointer to ObjC object
2039	bool isObjCRetainableType() const; // ObjC object or block pointer
2040	bool isObjCLifetimeType() const; // (array of)* retainable type
2041	bool isObjCIndirectLifetimeType() const; // (pointer to)* lifetime type
2042	bool isObjCNSObjectType() const; // __attribute__((NSObject))
2043	bool isObjCIndependentClassType() const; // __attribute__((objc_independent_class))
2044	// FIXME: change this to 'raw' interface type, so we can used 'interface' type
2045	// for the common case.
2046	bool isObjCObjectType() const; // NSString or typeof(*(id)0)
2047	bool isObjCQualifiedInterfaceType() const; // NSString<foo>
2048	bool isObjCQualifiedIdType() const; // id<foo>
2049	bool isObjCQualifiedClassType() const; // Class<foo>
2050	bool isObjCObjectOrInterfaceType() const;
2051	bool isObjCIdType() const; // id
2052	bool isDecltypeType() const;
2053	/// Was this type written with the special inert-in-ARC __unsafe_unretained
2054	/// qualifier?
2055	///
2056	/// This approximates the answer to the following question: if this
2057	/// translation unit were compiled in ARC, would this type be qualified
2058	/// with __unsafe_unretained?
2059	bool isObjCInertUnsafeUnretainedType() const {
2060	return hasAttr(attr::ObjCInertUnsafeUnretained);
2061	}
2062
2063	/// Whether the type is Objective-C 'id' or a __kindof type of an
2064	/// object type, e.g., __kindof NSView * or __kindof id
2065	/// <NSCopying>.
2066	///
2067	/// \param bound Will be set to the bound on non-id subtype types,
2068	/// which will be (possibly specialized) Objective-C class type, or
2069	/// null for 'id.
2070	bool isObjCIdOrObjectKindOfType(const ASTContext &ctx,
2071	const ObjCObjectType *&bound) const;
2072
2073	bool isObjCClassType() const; // Class
2074
2075	/// Whether the type is Objective-C 'Class' or a __kindof type of an
2076	/// Class type, e.g., __kindof Class <NSCopying>.
2077	///
2078	/// Unlike \c isObjCIdOrObjectKindOfType, there is no relevant bound
2079	/// here because Objective-C's type system cannot express "a class
2080	/// object for a subclass of NSFoo".
2081	bool isObjCClassOrClassKindOfType() const;
2082
2083	bool isBlockCompatibleObjCPointerType(ASTContext &ctx) const;
2084	bool isObjCSelType() const; // Class
2085	bool isObjCBuiltinType() const; // 'id' or 'Class'
2086	bool isObjCARCBridgableType() const;
2087	bool isCARCBridgableType() const;
2088	bool isTemplateTypeParmType() const; // C++ template type parameter
2089	bool isNullPtrType() const; // C++11 std::nullptr_t
2090	bool isNothrowT() const; // C++ std::nothrow_t
2091	bool isAlignValT() const; // C++17 std::align_val_t
2092	bool isStdByteType() const; // C++17 std::byte
2093	bool isAtomicType() const; // C11 _Atomic()
2094	bool isUndeducedAutoType() const; // C++11 auto or
2095	// C++14 decltype(auto)
2096	bool isTypedefNameType() const; // typedef or alias template
2097
2098	#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
2099	bool is##Id##Type() const;
2100	#include "clang/Basic/OpenCLImageTypes.def"
2101
2102	bool isImageType() const; // Any OpenCL image type
2103
2104	bool isSamplerT() const; // OpenCL sampler_t
2105	bool isEventT() const; // OpenCL event_t
2106	bool isClkEventT() const; // OpenCL clk_event_t
2107	bool isQueueT() const; // OpenCL queue_t
2108	bool isReserveIDT() const; // OpenCL reserve_id_t
2109
2110	#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
2111	bool is##Id##Type() const;
2112	#include "clang/Basic/OpenCLExtensionTypes.def"
2113	// Type defined in cl_intel_device_side_avc_motion_estimation OpenCL extension
2114	bool isOCLIntelSubgroupAVCType() const;
2115	bool isOCLExtOpaqueType() const; // Any OpenCL extension type
2116
2117	bool isPipeType() const; // OpenCL pipe type
2118	bool isExtIntType() const; // Extended Int Type
2119	bool isOpenCLSpecificType() const; // Any OpenCL specific type
2120
2121	/// Determines if this type, which must satisfy
2122	/// isObjCLifetimeType(), is implicitly __unsafe_unretained rather
2123	/// than implicitly __strong.
2124	bool isObjCARCImplicitlyUnretainedType() const;
2125
2126	/// Check if the type is the CUDA device builtin surface type.
2127	bool isCUDADeviceBuiltinSurfaceType() const;
2128	/// Check if the type is the CUDA device builtin texture type.
2129	bool isCUDADeviceBuiltinTextureType() const;
2130
2131	/// Return the implicit lifetime for this type, which must not be dependent.
2132	Qualifiers::ObjCLifetime getObjCARCImplicitLifetime() const;
2133
2134	enum ScalarTypeKind {
2135	STK_CPointer,
2136	STK_BlockPointer,
2137	STK_ObjCObjectPointer,
2138	STK_MemberPointer,
2139	STK_Bool,
2140	STK_Integral,
2141	STK_Floating,
2142	STK_IntegralComplex,
2143	STK_FloatingComplex,
2144	STK_FixedPoint
2145	};
2146
2147	/// Given that this is a scalar type, classify it.
2148	ScalarTypeKind getScalarTypeKind() const;
2149
2150	TypeDependence getDependence() const {
2151	return static_cast<TypeDependence>(TypeBits.Dependence);
2152	}
2153
2154	/// Whether this type is an error type.
2155	bool containsErrors() const {
2156	return getDependence() & TypeDependence::Error;
2157	}
2158
2159	/// Whether this type is a dependent type, meaning that its definition
2160	/// somehow depends on a template parameter (C++ [temp.dep.type]).
2161	bool isDependentType() const {
2162	return getDependence() & TypeDependence::Dependent;
2163	}
2164
2165	/// Determine whether this type is an instantiation-dependent type,
2166	/// meaning that the type involves a template parameter (even if the
2167	/// definition does not actually depend on the type substituted for that
2168	/// template parameter).
2169	bool isInstantiationDependentType() const {
2170	return getDependence() & TypeDependence::Instantiation;
2171	}
2172
2173	/// Determine whether this type is an undeduced type, meaning that
2174	/// it somehow involves a C++11 'auto' type or similar which has not yet been
2175	/// deduced.
2176	bool isUndeducedType() const;
2177
2178	/// Whether this type is a variably-modified type (C99 6.7.5).
2179	bool isVariablyModifiedType() const {
2180	return getDependence() & TypeDependence::VariablyModified;
2181	}
2182
2183	/// Whether this type involves a variable-length array type
2184	/// with a definite size.
2185	bool hasSizedVLAType() const;
2186
2187	/// Whether this type is or contains a local or unnamed type.
2188	bool hasUnnamedOrLocalType() const;
2189
2190	bool isOverloadableType() const;
2191
2192	/// Determine wither this type is a C++ elaborated-type-specifier.
2193	bool isElaboratedTypeSpecifier() const;
2194
2195	bool canDecayToPointerType() const;
2196
2197	/// Whether this type is represented natively as a pointer. This includes
2198	/// pointers, references, block pointers, and Objective-C interface,
2199	/// qualified id, and qualified interface types, as well as nullptr_t.
2200	bool hasPointerRepresentation() const;
2201
2202	/// Whether this type can represent an objective pointer type for the
2203	/// purpose of GC'ability
2204	bool hasObjCPointerRepresentation() const;
2205
2206	/// Determine whether this type has an integer representation
2207	/// of some sort, e.g., it is an integer type or a vector.
2208	bool hasIntegerRepresentation() const;
2209
2210	/// Determine whether this type has an signed integer representation
2211	/// of some sort, e.g., it is an signed integer type or a vector.
2212	bool hasSignedIntegerRepresentation() const;
2213
2214	/// Determine whether this type has an unsigned integer representation
2215	/// of some sort, e.g., it is an unsigned integer type or a vector.
2216	bool hasUnsignedIntegerRepresentation() const;
2217
2218	/// Determine whether this type has a floating-point representation
2219	/// of some sort, e.g., it is a floating-point type or a vector thereof.
2220	bool hasFloatingRepresentation() const;
2221
2222	// Type Checking Functions: Check to see if this type is structurally the
2223	// specified type, ignoring typedefs and qualifiers, and return a pointer to
2224	// the best type we can.
2225	const RecordType *getAsStructureType() const;
2226	/// NOTE: getAs*ArrayType are methods on ASTContext.
2227	const RecordType *getAsUnionType() const;
2228	const ComplexType *getAsComplexIntegerType() const; // GCC complex int type.
2229	const ObjCObjectType *getAsObjCInterfaceType() const;
2230
2231	// The following is a convenience method that returns an ObjCObjectPointerType
2232	// for object declared using an interface.
2233	const ObjCObjectPointerType *getAsObjCInterfacePointerType() const;
2234	const ObjCObjectPointerType *getAsObjCQualifiedIdType() const;
2235	const ObjCObjectPointerType *getAsObjCQualifiedClassType() const;
2236	const ObjCObjectType *getAsObjCQualifiedInterfaceType() const;
2237
2238	/// Retrieves the CXXRecordDecl that this type refers to, either
2239	/// because the type is a RecordType or because it is the injected-class-name
2240	/// type of a class template or class template partial specialization.
2241	CXXRecordDecl *getAsCXXRecordDecl() const;
2242
2243	/// Retrieves the RecordDecl this type refers to.
2244	RecordDecl *getAsRecordDecl() const;
2245
2246	/// Retrieves the TagDecl that this type refers to, either
2247	/// because the type is a TagType or because it is the injected-class-name
2248	/// type of a class template or class template partial specialization.
2249	TagDecl *getAsTagDecl() const;
2250
2251	/// If this is a pointer or reference to a RecordType, return the
2252	/// CXXRecordDecl that the type refers to.
2253	///
2254	/// If this is not a pointer or reference, or the type being pointed to does
2255	/// not refer to a CXXRecordDecl, returns NULL.
2256	const CXXRecordDecl *getPointeeCXXRecordDecl() const;
2257
2258	/// Get the DeducedType whose type will be deduced for a variable with
2259	/// an initializer of this type. This looks through declarators like pointer
2260	/// types, but not through decltype or typedefs.
2261	DeducedType *getContainedDeducedType() const;
2262
2263	/// Get the AutoType whose type will be deduced for a variable with
2264	/// an initializer of this type. This looks through declarators like pointer
2265	/// types, but not through decltype or typedefs.
2266	AutoType *getContainedAutoType() const {
2267	return dyn_cast_or_null<AutoType>(getContainedDeducedType());
2268	}
2269
2270	/// Determine whether this type was written with a leading 'auto'
2271	/// corresponding to a trailing return type (possibly for a nested
2272	/// function type within a pointer to function type or similar).
2273	bool hasAutoForTrailingReturnType() const;
2274
2275	/// Member-template getAs<specific type>'. Look through sugar for
2276	/// an instance of \<specific type>. This scheme will eventually
2277	/// replace the specific getAsXXXX methods above.
2278	///
2279	/// There are some specializations of this member template listed
2280	/// immediately following this class.
2281	template <typename T> const T *getAs() const;
2282
2283	/// Member-template getAsAdjusted<specific type>. Look through specific kinds
2284	/// of sugar (parens, attributes, etc) for an instance of \<specific type>.
2285	/// This is used when you need to walk over sugar nodes that represent some
2286	/// kind of type adjustment from a type that was written as a \<specific type>
2287	/// to another type that is still canonically a \<specific type>.
2288	template <typename T> const T *getAsAdjusted() const;
2289
2290	/// A variant of getAs<> for array types which silently discards
2291	/// qualifiers from the outermost type.
2292	const ArrayType *getAsArrayTypeUnsafe() const;
2293
2294	/// Member-template castAs<specific type>. Look through sugar for
2295	/// the underlying instance of \<specific type>.
2296	///
2297	/// This method has the same relationship to getAs<T> as cast<T> has
2298	/// to dyn_cast<T>; which is to say, the underlying type must
2299	/// have the intended type, and this method will never return null.
2300	template <typename T> const T *castAs() const;
2301
2302	/// A variant of castAs<> for array type which silently discards
2303	/// qualifiers from the outermost type.
2304	const ArrayType *castAsArrayTypeUnsafe() const;
2305
2306	/// Determine whether this type had the specified attribute applied to it
2307	/// (looking through top-level type sugar).
2308	bool hasAttr(attr::Kind AK) const;
2309
2310	/// Get the base element type of this type, potentially discarding type
2311	/// qualifiers. This should never be used when type qualifiers
2312	/// are meaningful.
2313	const Type *getBaseElementTypeUnsafe() const;
2314
2315	/// If this is an array type, return the element type of the array,
2316	/// potentially with type qualifiers missing.
2317	/// This should never be used when type qualifiers are meaningful.
2318	const Type *getArrayElementTypeNoTypeQual() const;
2319
2320	/// If this is a pointer type, return the pointee type.
2321	/// If this is an array type, return the array element type.
2322	/// This should never be used when type qualifiers are meaningful.
2323	const Type *getPointeeOrArrayElementType() const;
2324
2325	/// If this is a pointer, ObjC object pointer, or block
2326	/// pointer, this returns the respective pointee.
2327	QualType getPointeeType() const;
2328
2329	/// Return the specified type with any "sugar" removed from the type,
2330	/// removing any typedefs, typeofs, etc., as well as any qualifiers.
2331	const Type *getUnqualifiedDesugaredType() const;
2332
2333	/// More type predicates useful for type checking/promotion
2334	bool isPromotableIntegerType() const; // C99 6.3.1.1p2
2335
2336	/// Return true if this is an integer type that is
2337	/// signed, according to C99 6.2.5p4 [char, signed char, short, int, long..],
2338	/// or an enum decl which has a signed representation.
2339	bool isSignedIntegerType() const;
2340
2341	/// Return true if this is an integer type that is
2342	/// unsigned, according to C99 6.2.5p6 [which returns true for _Bool],
2343	/// or an enum decl which has an unsigned representation.
2344	bool isUnsignedIntegerType() const;
2345
2346	/// Determines whether this is an integer type that is signed or an
2347	/// enumeration types whose underlying type is a signed integer type.
2348	bool isSignedIntegerOrEnumerationType() const;
2349
2350	/// Determines whether this is an integer type that is unsigned or an
2351	/// enumeration types whose underlying type is a unsigned integer type.
2352	bool isUnsignedIntegerOrEnumerationType() const;
2353
2354	/// Return true if this is a fixed point type according to
2355	/// ISO/IEC JTC1 SC22 WG14 N1169.
2356	bool isFixedPointType() const;
2357
2358	/// Return true if this is a fixed point or integer type.
2359	bool isFixedPointOrIntegerType() const;
2360
2361	/// Return true if this is a saturated fixed point type according to
2362	/// ISO/IEC JTC1 SC22 WG14 N1169. This type can be signed or unsigned.
2363	bool isSaturatedFixedPointType() const;
2364
2365	/// Return true if this is a saturated fixed point type according to
2366	/// ISO/IEC JTC1 SC22 WG14 N1169. This type can be signed or unsigned.
2367	bool isUnsaturatedFixedPointType() const;
2368
2369	/// Return true if this is a fixed point type that is signed according
2370	/// to ISO/IEC JTC1 SC22 WG14 N1169. This type can also be saturated.
2371	bool isSignedFixedPointType() const;
2372
2373	/// Return true if this is a fixed point type that is unsigned according
2374	/// to ISO/IEC JTC1 SC22 WG14 N1169. This type can also be saturated.
2375	bool isUnsignedFixedPointType() const;
2376
2377	/// Return true if this is not a variable sized type,
2378	/// according to the rules of C99 6.7.5p3. It is not legal to call this on
2379	/// incomplete types.
2380	bool isConstantSizeType() const;
2381
2382	/// Returns true if this type can be represented by some
2383	/// set of type specifiers.
2384	bool isSpecifierType() const;
2385
2386	/// Determine the linkage of this type.
2387	Linkage getLinkage() const;
2388
2389	/// Determine the visibility of this type.
2390	Visibility getVisibility() const {
2391	return getLinkageAndVisibility().getVisibility();
2392	}
2393
2394	/// Return true if the visibility was explicitly set is the code.
2395	bool isVisibilityExplicit() const {
2396	return getLinkageAndVisibility().isVisibilityExplicit();
2397	}
2398
2399	/// Determine the linkage and visibility of this type.
2400	LinkageInfo getLinkageAndVisibility() const;
2401
2402	/// True if the computed linkage is valid. Used for consistency
2403	/// checking. Should always return true.
2404	bool isLinkageValid() const;
2405
2406	/// Determine the nullability of the given type.
2407	///
2408	/// Note that nullability is only captured as sugar within the type
2409	/// system, not as part of the canonical type, so nullability will
2410	/// be lost by canonicalization and desugaring.
2411	Optional<NullabilityKind> getNullability(const ASTContext &context) const;
2412
2413	/// Determine whether the given type can have a nullability
2414	/// specifier applied to it, i.e., if it is any kind of pointer type.
2415	///
2416	/// \param ResultIfUnknown The value to return if we don't yet know whether
2417	/// this type can have nullability because it is dependent.
2418	bool canHaveNullability(bool ResultIfUnknown = true) const;
2419
2420	/// Retrieve the set of substitutions required when accessing a member
2421	/// of the Objective-C receiver type that is declared in the given context.
2422	///
2423	/// \c *this is the type of the object we're operating on, e.g., the
2424	/// receiver for a message send or the base of a property access, and is
2425	/// expected to be of some object or object pointer type.
2426	///
2427	/// \param dc The declaration context for which we are building up a
2428	/// substitution mapping, which should be an Objective-C class, extension,
2429	/// category, or method within.
2430	///
2431	/// \returns an array of type arguments that can be substituted for
2432	/// the type parameters of the given declaration context in any type described
2433	/// within that context, or an empty optional to indicate that no
2434	/// substitution is required.
2435	Optional<ArrayRef<QualType>>
2436	getObjCSubstitutions(const DeclContext *dc) const;
2437
2438	/// Determines if this is an ObjC interface type that may accept type
2439	/// parameters.
2440	bool acceptsObjCTypeParams() const;
2441
2442	const char *getTypeClassName() const;
2443
2444	QualType getCanonicalTypeInternal() const {
2445	return CanonicalType;
2446	}
2447
2448	CanQualType getCanonicalTypeUnqualified() const; // in CanonicalType.h
2449	void dump() const;
2450	void dump(llvm::raw_ostream &OS, const ASTContext &Context) const;
2451	};
2452
2453	/// This will check for a TypedefType by removing any existing sugar
2454	/// until it reaches a TypedefType or a non-sugared type.
2455	template <> const TypedefType *Type::getAs() const;
2456
2457	/// This will check for a TemplateSpecializationType by removing any
2458	/// existing sugar until it reaches a TemplateSpecializationType or a
2459	/// non-sugared type.
2460	template <> const TemplateSpecializationType *Type::getAs() const;
2461
2462	/// This will check for an AttributedType by removing any existing sugar
2463	/// until it reaches an AttributedType or a non-sugared type.
2464	template <> const AttributedType *Type::getAs() const;
2465
2466	// We can do canonical leaf types faster, because we don't have to
2467	// worry about preserving child type decoration.
2468	#define TYPE(Class, Base)
2469	#define LEAF_TYPE(Class) \
2470	template <> inline const Class##Type *Type::getAs() const { \
2471	return dyn_cast<Class##Type>(CanonicalType); \
2472	} \
2473	template <> inline const Class##Type *Type::castAs() const { \
2474	return cast<Class##Type>(CanonicalType); \
2475	}
2476	#include "clang/AST/TypeNodes.inc"
2477
2478	/// This class is used for builtin types like 'int'. Builtin
2479	/// types are always canonical and have a literal name field.
2480	class BuiltinType : public Type {
2481	public:
2482	enum Kind {
2483	// OpenCL image types
2484	#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) Id,
2485	#include "clang/Basic/OpenCLImageTypes.def"
2486	// OpenCL extension types
2487	#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) Id,
2488	#include "clang/Basic/OpenCLExtensionTypes.def"
2489	// SVE Types
2490	#define SVE_TYPE(Name, Id, SingletonId) Id,
2491	#include "clang/Basic/AArch64SVEACLETypes.def"
2492	// PPC MMA Types
2493	#define PPC_VECTOR_TYPE(Name, Id, Size) Id,
2494	#include "clang/Basic/PPCTypes.def"
2495	// RVV Types
2496	#define RVV_TYPE(Name, Id, SingletonId) Id,
2497	#include "clang/Basic/RISCVVTypes.def"
2498	// All other builtin types
2499	#define BUILTIN_TYPE(Id, SingletonId) Id,
2500	#define LAST_BUILTIN_TYPE(Id) LastKind = Id
2501	#include "clang/AST/BuiltinTypes.def"
2502	};
2503
2504	private:
2505	friend class ASTContext; // ASTContext creates these.
2506
2507	BuiltinType(Kind K)
2508	: Type(Builtin, QualType(),
2509	K == Dependent ? TypeDependence::DependentInstantiation
2510	: TypeDependence::None) {
2511	BuiltinTypeBits.Kind = K;
2512	}
2513
2514	public:
2515	Kind getKind() const { return static_cast<Kind>(BuiltinTypeBits.Kind); }
2516	StringRef getName(const PrintingPolicy &Policy) const;
2517
2518	const char *getNameAsCString(const PrintingPolicy &Policy) const {
2519	// The StringRef is null-terminated.
2520	StringRef str = getName(Policy);
2521	assert(!str.empty() && str.data()[str.size()] == '\0')((!str.empty() && str.data()[str.size()] == '\0') ? static_cast <void> (0) : __assert_fail ("!str.empty() && str.data()[str.size()] == '\\0'" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 2521, __PRETTY_FUNCTION__));
2522	return str.data();
2523	}
2524
2525	bool isSugared() const { return false; }
2526	QualType desugar() const { return QualType(this, 0); }
2527
2528	bool isInteger() const {
2529	return getKind() >= Bool && getKind() <= Int128;
2530	}
2531
2532	bool isSignedInteger() const {
2533	return getKind() >= Char_S && getKind() <= Int128;
2534	}
2535
2536	bool isUnsignedInteger() const {
2537	return getKind() >= Bool && getKind() <= UInt128;
2538	}
2539
2540	bool isFloatingPoint() const {
2541	return getKind() >= Half && getKind() <= Float128;
2542	}
2543
2544	/// Determines whether the given kind corresponds to a placeholder type.
2545	static bool isPlaceholderTypeKind(Kind K) {
2546	return K >= Overload;
2547	}
2548
2549	/// Determines whether this type is a placeholder type, i.e. a type
2550	/// which cannot appear in arbitrary positions in a fully-formed
2551	/// expression.
2552	bool isPlaceholderType() const {
2553	return isPlaceholderTypeKind(getKind());
2554	}
2555
2556	/// Determines whether this type is a placeholder type other than
2557	/// Overload. Most placeholder types require only syntactic
2558	/// information about their context in order to be resolved (e.g.
2559	/// whether it is a call expression), which means they can (and
2560	/// should) be resolved in an earlier "phase" of analysis.
2561	/// Overload expressions sometimes pick up further information
2562	/// from their context, like whether the context expects a
2563	/// specific function-pointer type, and so frequently need
2564	/// special treatment.
2565	bool isNonOverloadPlaceholderType() const {
2566	return getKind() > Overload;
2567	}
2568
2569	static bool classof(const Type *T) { return T->getTypeClass() == Builtin; }
2570	};
2571
2572	/// Complex values, per C99 6.2.5p11. This supports the C99 complex
2573	/// types (_Complex float etc) as well as the GCC integer complex extensions.
2574	class ComplexType : public Type, public llvm::FoldingSetNode {
2575	friend class ASTContext; // ASTContext creates these.
2576
2577	QualType ElementType;
2578
2579	ComplexType(QualType Element, QualType CanonicalPtr)
2580	: Type(Complex, CanonicalPtr, Element->getDependence()),
2581	ElementType(Element) {}
2582
2583	public:
2584	QualType getElementType() const { return ElementType; }
2585
2586	bool isSugared() const { return false; }
2587	QualType desugar() const { return QualType(this, 0); }
2588
2589	void Profile(llvm::FoldingSetNodeID &ID) {
2590	Profile(ID, getElementType());
2591	}
2592
2593	static void Profile(llvm::FoldingSetNodeID &ID, QualType Element) {
2594	ID.AddPointer(Element.getAsOpaquePtr());
2595	}
2596
2597	static bool classof(const Type *T) { return T->getTypeClass() == Complex; }
2598	};
2599
2600	/// Sugar for parentheses used when specifying types.
2601	class ParenType : public Type, public llvm::FoldingSetNode {
2602	friend class ASTContext; // ASTContext creates these.
2603
2604	QualType Inner;
2605
2606	ParenType(QualType InnerType, QualType CanonType)
2607	: Type(Paren, CanonType, InnerType->getDependence()), Inner(InnerType) {}
2608
2609	public:
2610	QualType getInnerType() const { return Inner; }
2611
2612	bool isSugared() const { return true; }
2613	QualType desugar() const { return getInnerType(); }
2614
2615	void Profile(llvm::FoldingSetNodeID &ID) {
2616	Profile(ID, getInnerType());
2617	}
2618
2619	static void Profile(llvm::FoldingSetNodeID &ID, QualType Inner) {
2620	Inner.Profile(ID);
2621	}
2622
2623	static bool classof(const Type *T) { return T->getTypeClass() == Paren; }
2624	};
2625
2626	/// PointerType - C99 6.7.5.1 - Pointer Declarators.
2627	class PointerType : public Type, public llvm::FoldingSetNode {
2628	friend class ASTContext; // ASTContext creates these.
2629
2630	QualType PointeeType;
2631
2632	PointerType(QualType Pointee, QualType CanonicalPtr)
2633	: Type(Pointer, CanonicalPtr, Pointee->getDependence()),
2634	PointeeType(Pointee) {}
2635
2636	public:
2637	QualType getPointeeType() const { return PointeeType; }
2638
2639	bool isSugared() const { return false; }
2640	QualType desugar() const { return QualType(this, 0); }
2641
2642	void Profile(llvm::FoldingSetNodeID &ID) {
2643	Profile(ID, getPointeeType());
2644	}
2645
2646	static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee) {
2647	ID.AddPointer(Pointee.getAsOpaquePtr());
2648	}
2649
2650	static bool classof(const Type *T) { return T->getTypeClass() == Pointer; }
2651	};
2652
2653	/// Represents a type which was implicitly adjusted by the semantic
2654	/// engine for arbitrary reasons. For example, array and function types can
2655	/// decay, and function types can have their calling conventions adjusted.
2656	class AdjustedType : public Type, public llvm::FoldingSetNode {
2657	QualType OriginalTy;
2658	QualType AdjustedTy;
2659
2660	protected:
2661	friend class ASTContext; // ASTContext creates these.
2662
2663	AdjustedType(TypeClass TC, QualType OriginalTy, QualType AdjustedTy,
2664	QualType CanonicalPtr)
2665	: Type(TC, CanonicalPtr, OriginalTy->getDependence()),
2666	OriginalTy(OriginalTy), AdjustedTy(AdjustedTy) {}
2667
2668	public:
2669	QualType getOriginalType() const { return OriginalTy; }
2670	QualType getAdjustedType() const { return AdjustedTy; }
2671
2672	bool isSugared() const { return true; }
2673	QualType desugar() const { return AdjustedTy; }
2674
2675	void Profile(llvm::FoldingSetNodeID &ID) {
2676	Profile(ID, OriginalTy, AdjustedTy);
2677	}
2678
2679	static void Profile(llvm::FoldingSetNodeID &ID, QualType Orig, QualType New) {
2680	ID.AddPointer(Orig.getAsOpaquePtr());
2681	ID.AddPointer(New.getAsOpaquePtr());
2682	}
2683
2684	static bool classof(const Type *T) {
2685	return T->getTypeClass() == Adjusted \|\| T->getTypeClass() == Decayed;
2686	}
2687	};
2688
2689	/// Represents a pointer type decayed from an array or function type.
2690	class DecayedType : public AdjustedType {
2691	friend class ASTContext; // ASTContext creates these.
2692
2693	inline
2694	DecayedType(QualType OriginalType, QualType Decayed, QualType Canonical);
2695
2696	public:
2697	QualType getDecayedType() const { return getAdjustedType(); }
2698
2699	inline QualType getPointeeType() const;
2700
2701	static bool classof(const Type *T) { return T->getTypeClass() == Decayed; }
2702	};
2703
2704	/// Pointer to a block type.
2705	/// This type is to represent types syntactically represented as
2706	/// "void (^)(int)", etc. Pointee is required to always be a function type.
2707	class BlockPointerType : public Type, public llvm::FoldingSetNode {
2708	friend class ASTContext; // ASTContext creates these.
2709
2710	// Block is some kind of pointer type
2711	QualType PointeeType;
2712
2713	BlockPointerType(QualType Pointee, QualType CanonicalCls)
2714	: Type(BlockPointer, CanonicalCls, Pointee->getDependence()),
2715	PointeeType(Pointee) {}
2716
2717	public:
2718	// Get the pointee type. Pointee is required to always be a function type.
2719	QualType getPointeeType() const { return PointeeType; }
2720
2721	bool isSugared() const { return false; }
2722	QualType desugar() const { return QualType(this, 0); }
2723
2724	void Profile(llvm::FoldingSetNodeID &ID) {
2725	Profile(ID, getPointeeType());
2726	}
2727
2728	static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee) {
2729	ID.AddPointer(Pointee.getAsOpaquePtr());
2730	}
2731
2732	static bool classof(const Type *T) {
2733	return T->getTypeClass() == BlockPointer;
2734	}
2735	};
2736
2737	/// Base for LValueReferenceType and RValueReferenceType
2738	class ReferenceType : public Type, public llvm::FoldingSetNode {
2739	QualType PointeeType;
2740
2741	protected:
2742	ReferenceType(TypeClass tc, QualType Referencee, QualType CanonicalRef,
2743	bool SpelledAsLValue)
2744	: Type(tc, CanonicalRef, Referencee->getDependence()),
2745	PointeeType(Referencee) {
2746	ReferenceTypeBits.SpelledAsLValue = SpelledAsLValue;
2747	ReferenceTypeBits.InnerRef = Referencee->isReferenceType();
2748	}
2749
2750	public:
2751	bool isSpelledAsLValue() const { return ReferenceTypeBits.SpelledAsLValue; }
2752	bool isInnerRef() const { return ReferenceTypeBits.InnerRef; }
2753
2754	QualType getPointeeTypeAsWritten() const { return PointeeType; }
2755
2756	QualType getPointeeType() const {
2757	// FIXME: this might strip inner qualifiers; okay?
2758	const ReferenceType *T = this;
2759	while (T->isInnerRef())
2760	T = T->PointeeType->castAs<ReferenceType>();
2761	return T->PointeeType;
2762	}
2763
2764	void Profile(llvm::FoldingSetNodeID &ID) {
2765	Profile(ID, PointeeType, isSpelledAsLValue());
2766	}
2767
2768	static void Profile(llvm::FoldingSetNodeID &ID,
2769	QualType Referencee,
2770	bool SpelledAsLValue) {
2771	ID.AddPointer(Referencee.getAsOpaquePtr());
2772	ID.AddBoolean(SpelledAsLValue);
2773	}
2774
2775	static bool classof(const Type *T) {
2776	return T->getTypeClass() == LValueReference \|\|
2777	T->getTypeClass() == RValueReference;
2778	}
2779	};
2780
2781	/// An lvalue reference type, per C++11 [dcl.ref].
2782	class LValueReferenceType : public ReferenceType {
2783	friend class ASTContext; // ASTContext creates these
2784
2785	LValueReferenceType(QualType Referencee, QualType CanonicalRef,
2786	bool SpelledAsLValue)
2787	: ReferenceType(LValueReference, Referencee, CanonicalRef,
2788	SpelledAsLValue) {}
2789
2790	public:
2791	bool isSugared() const { return false; }
2792	QualType desugar() const { return QualType(this, 0); }
2793
2794	static bool classof(const Type *T) {
2795	return T->getTypeClass() == LValueReference;
2796	}
2797	};
2798
2799	/// An rvalue reference type, per C++11 [dcl.ref].
2800	class RValueReferenceType : public ReferenceType {
2801	friend class ASTContext; // ASTContext creates these
2802
2803	RValueReferenceType(QualType Referencee, QualType CanonicalRef)
2804	: ReferenceType(RValueReference, Referencee, CanonicalRef, false) {}
2805
2806	public:
2807	bool isSugared() const { return false; }
2808	QualType desugar() const { return QualType(this, 0); }
2809
2810	static bool classof(const Type *T) {
2811	return T->getTypeClass() == RValueReference;
2812	}
2813	};
2814
2815	/// A pointer to member type per C++ 8.3.3 - Pointers to members.
2816	///
2817	/// This includes both pointers to data members and pointer to member functions.
2818	class MemberPointerType : public Type, public llvm::FoldingSetNode {
2819	friend class ASTContext; // ASTContext creates these.
2820
2821	QualType PointeeType;
2822
2823	/// The class of which the pointee is a member. Must ultimately be a
2824	/// RecordType, but could be a typedef or a template parameter too.
2825	const Type *Class;
2826
2827	MemberPointerType(QualType Pointee, const Type *Cls, QualType CanonicalPtr)
2828	: Type(MemberPointer, CanonicalPtr,
2829	(Cls->getDependence() & ~TypeDependence::VariablyModified) \|
2830	Pointee->getDependence()),
2831	PointeeType(Pointee), Class(Cls) {}
2832
2833	public:
2834	QualType getPointeeType() const { return PointeeType; }
2835
2836	/// Returns true if the member type (i.e. the pointee type) is a
2837	/// function type rather than a data-member type.
2838	bool isMemberFunctionPointer() const {
2839	return PointeeType->isFunctionProtoType();
2840	}
2841
2842	/// Returns true if the member type (i.e. the pointee type) is a
2843	/// data type rather than a function type.
2844	bool isMemberDataPointer() const {
2845	return !PointeeType->isFunctionProtoType();
2846	}
2847
2848	const Type *getClass() const { return Class; }
2849	CXXRecordDecl *getMostRecentCXXRecordDecl() const;
2850
2851	bool isSugared() const { return false; }
2852	QualType desugar() const { return QualType(this, 0); }
2853
2854	void Profile(llvm::FoldingSetNodeID &ID) {
2855	Profile(ID, getPointeeType(), getClass());
2856	}
2857
2858	static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee,
2859	const Type *Class) {
2860	ID.AddPointer(Pointee.getAsOpaquePtr());
2861	ID.AddPointer(Class);
2862	}
2863
2864	static bool classof(const Type *T) {
2865	return T->getTypeClass() == MemberPointer;
2866	}
2867	};
2868
2869	/// Represents an array type, per C99 6.7.5.2 - Array Declarators.
2870	class ArrayType : public Type, public llvm::FoldingSetNode {
2871	public:
2872	/// Capture whether this is a normal array (e.g. int X[4])
2873	/// an array with a static size (e.g. int X[static 4]), or an array
2874	/// with a star size (e.g. int X[*]).
2875	/// 'static' is only allowed on function parameters.
2876	enum ArraySizeModifier {
2877	Normal, Static, Star
2878	};
2879
2880	private:
2881	/// The element type of the array.
2882	QualType ElementType;
2883
2884	protected:
2885	friend class ASTContext; // ASTContext creates these.
2886
2887	ArrayType(TypeClass tc, QualType et, QualType can, ArraySizeModifier sm,
2888	unsigned tq, const Expr *sz = nullptr);
2889
2890	public:
2891	QualType getElementType() const { return ElementType; }
2892
2893	ArraySizeModifier getSizeModifier() const {
2894	return ArraySizeModifier(ArrayTypeBits.SizeModifier);
2895	}
2896
2897	Qualifiers getIndexTypeQualifiers() const {
2898	return Qualifiers::fromCVRMask(getIndexTypeCVRQualifiers());
2899	}
2900
2901	unsigned getIndexTypeCVRQualifiers() const {
2902	return ArrayTypeBits.IndexTypeQuals;
2903	}
2904
2905	static bool classof(const Type *T) {
2906	return T->getTypeClass() == ConstantArray \|\|
2907	T->getTypeClass() == VariableArray \|\|
2908	T->getTypeClass() == IncompleteArray \|\|
2909	T->getTypeClass() == DependentSizedArray;
2910	}
2911	};
2912
2913	/// Represents the canonical version of C arrays with a specified constant size.
2914	/// For example, the canonical type for 'int A[4 + 4*100]' is a
2915	/// ConstantArrayType where the element type is 'int' and the size is 404.
2916	class ConstantArrayType final
2917	: public ArrayType,
2918	private llvm::TrailingObjects<ConstantArrayType, const Expr *> {
2919	friend class ASTContext; // ASTContext creates these.
2920	friend TrailingObjects;
2921
2922	llvm::APInt Size; // Allows us to unique the type.
2923
2924	ConstantArrayType(QualType et, QualType can, const llvm::APInt &size,
2925	const Expr *sz, ArraySizeModifier sm, unsigned tq)
2926	: ArrayType(ConstantArray, et, can, sm, tq, sz), Size(size) {
2927	ConstantArrayTypeBits.HasStoredSizeExpr = sz != nullptr;
2928	if (ConstantArrayTypeBits.HasStoredSizeExpr) {
2929	assert(!can.isNull() && "canonical constant array should not have size")((!can.isNull() && "canonical constant array should not have size" ) ? static_cast<void> (0) : __assert_fail ("!can.isNull() && \"canonical constant array should not have size\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 2929, __PRETTY_FUNCTION__));
2930	getTrailingObjects<const Expr>() = sz;
2931	}
2932	}
2933
2934	unsigned numTrailingObjects(OverloadToken<const Expr*>) const {
2935	return ConstantArrayTypeBits.HasStoredSizeExpr;
2936	}
2937
2938	public:
2939	const llvm::APInt &getSize() const { return Size; }
2940	const Expr *getSizeExpr() const {
2941	return ConstantArrayTypeBits.HasStoredSizeExpr
2942	? getTrailingObjects<const Expr >()
2943	: nullptr;
2944	}
2945	bool isSugared() const { return false; }
2946	QualType desugar() const { return QualType(this, 0); }
2947
2948	/// Determine the number of bits required to address a member of
2949	// an array with the given element type and number of elements.
2950	static unsigned getNumAddressingBits(const ASTContext &Context,
2951	QualType ElementType,
2952	const llvm::APInt &NumElements);
2953
2954	/// Determine the maximum number of active bits that an array's size
2955	/// can require, which limits the maximum size of the array.
2956	static unsigned getMaxSizeBits(const ASTContext &Context);
2957
2958	void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx) {
2959	Profile(ID, Ctx, getElementType(), getSize(), getSizeExpr(),
2960	getSizeModifier(), getIndexTypeCVRQualifiers());
2961	}
2962
2963	static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx,
2964	QualType ET, const llvm::APInt &ArraySize,
2965	const Expr *SizeExpr, ArraySizeModifier SizeMod,
2966	unsigned TypeQuals);
2967
2968	static bool classof(const Type *T) {
2969	return T->getTypeClass() == ConstantArray;
2970	}
2971	};
2972
2973	/// Represents a C array with an unspecified size. For example 'int A[]' has
2974	/// an IncompleteArrayType where the element type is 'int' and the size is
2975	/// unspecified.
2976	class IncompleteArrayType : public ArrayType {
2977	friend class ASTContext; // ASTContext creates these.
2978
2979	IncompleteArrayType(QualType et, QualType can,
2980	ArraySizeModifier sm, unsigned tq)
2981	: ArrayType(IncompleteArray, et, can, sm, tq) {}
2982
2983	public:
2984	friend class StmtIteratorBase;
2985
2986	bool isSugared() const { return false; }
2987	QualType desugar() const { return QualType(this, 0); }
2988
2989	static bool classof(const Type *T) {
2990	return T->getTypeClass() == IncompleteArray;
2991	}
2992
2993	void Profile(llvm::FoldingSetNodeID &ID) {
2994	Profile(ID, getElementType(), getSizeModifier(),
2995	getIndexTypeCVRQualifiers());
2996	}
2997
2998	static void Profile(llvm::FoldingSetNodeID &ID, QualType ET,
2999	ArraySizeModifier SizeMod, unsigned TypeQuals) {
3000	ID.AddPointer(ET.getAsOpaquePtr());
3001	ID.AddInteger(SizeMod);
3002	ID.AddInteger(TypeQuals);
3003	}
3004	};
3005
3006	/// Represents a C array with a specified size that is not an
3007	/// integer-constant-expression. For example, 'int s[x+foo()]'.
3008	/// Since the size expression is an arbitrary expression, we store it as such.
3009	///
3010	/// Note: VariableArrayType's aren't uniqued (since the expressions aren't) and
3011	/// should not be: two lexically equivalent variable array types could mean
3012	/// different things, for example, these variables do not have the same type
3013	/// dynamically:
3014	///
3015	/// void foo(int x) {
3016	/// int Y[x];
3017	/// ++x;
3018	/// int Z[x];
3019	/// }
3020	class VariableArrayType : public ArrayType {
3021	friend class ASTContext; // ASTContext creates these.
3022
3023	/// An assignment-expression. VLA's are only permitted within
3024	/// a function block.
3025	Stmt *SizeExpr;
3026
3027	/// The range spanned by the left and right array brackets.
3028	SourceRange Brackets;
3029
3030	VariableArrayType(QualType et, QualType can, Expr *e,
3031	ArraySizeModifier sm, unsigned tq,
3032	SourceRange brackets)
3033	: ArrayType(VariableArray, et, can, sm, tq, e),
3034	SizeExpr((Stmt*) e), Brackets(brackets) {}
3035
3036	public:
3037	friend class StmtIteratorBase;
3038
3039	Expr *getSizeExpr() const {
3040	// We use C-style casts instead of cast<> here because we do not wish
3041	// to have a dependency of Type.h on Stmt.h/Expr.h.
3042	return (Expr*) SizeExpr;
3043	}
3044
3045	SourceRange getBracketsRange() const { return Brackets; }
3046	SourceLocation getLBracketLoc() const { return Brackets.getBegin(); }
3047	SourceLocation getRBracketLoc() const { return Brackets.getEnd(); }
3048
3049	bool isSugared() const { return false; }
3050	QualType desugar() const { return QualType(this, 0); }
3051
3052	static bool classof(const Type *T) {
3053	return T->getTypeClass() == VariableArray;
3054	}
3055
3056	void Profile(llvm::FoldingSetNodeID &ID) {
3057	llvm_unreachable("Cannot unique VariableArrayTypes.")::llvm::llvm_unreachable_internal("Cannot unique VariableArrayTypes." , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 3057);
3058	}
3059	};
3060
3061	/// Represents an array type in C++ whose size is a value-dependent expression.
3062	///
3063	/// For example:
3064	/// \code
3065	/// template<typename T, int Size>
3066	/// class array {
3067	/// T data[Size];
3068	/// };
3069	/// \endcode
3070	///
3071	/// For these types, we won't actually know what the array bound is
3072	/// until template instantiation occurs, at which point this will
3073	/// become either a ConstantArrayType or a VariableArrayType.
3074	class DependentSizedArrayType : public ArrayType {
3075	friend class ASTContext; // ASTContext creates these.
3076
3077	const ASTContext &Context;
3078
3079	/// An assignment expression that will instantiate to the
3080	/// size of the array.
3081	///
3082	/// The expression itself might be null, in which case the array
3083	/// type will have its size deduced from an initializer.
3084	Stmt *SizeExpr;
3085
3086	/// The range spanned by the left and right array brackets.
3087	SourceRange Brackets;
3088
3089	DependentSizedArrayType(const ASTContext &Context, QualType et, QualType can,
3090	Expr *e, ArraySizeModifier sm, unsigned tq,
3091	SourceRange brackets);
3092
3093	public:
3094	friend class StmtIteratorBase;
3095
3096	Expr *getSizeExpr() const {
3097	// We use C-style casts instead of cast<> here because we do not wish
3098	// to have a dependency of Type.h on Stmt.h/Expr.h.
3099	return (Expr*) SizeExpr;
3100	}
3101
3102	SourceRange getBracketsRange() const { return Brackets; }
3103	SourceLocation getLBracketLoc() const { return Brackets.getBegin(); }
3104	SourceLocation getRBracketLoc() const { return Brackets.getEnd(); }
3105
3106	bool isSugared() const { return false; }
3107	QualType desugar() const { return QualType(this, 0); }
3108
3109	static bool classof(const Type *T) {
3110	return T->getTypeClass() == DependentSizedArray;
3111	}
3112
3113	void Profile(llvm::FoldingSetNodeID &ID) {
3114	Profile(ID, Context, getElementType(),
3115	getSizeModifier(), getIndexTypeCVRQualifiers(), getSizeExpr());
3116	}
3117
3118	static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
3119	QualType ET, ArraySizeModifier SizeMod,
3120	unsigned TypeQuals, Expr *E);
3121	};
3122
3123	/// Represents an extended address space qualifier where the input address space
3124	/// value is dependent. Non-dependent address spaces are not represented with a
3125	/// special Type subclass; they are stored on an ExtQuals node as part of a QualType.
3126	///
3127	/// For example:
3128	/// \code
3129	/// template<typename T, int AddrSpace>
3130	/// class AddressSpace {
3131	/// typedef T __attribute__((address_space(AddrSpace))) type;
3132	/// }
3133	/// \endcode
3134	class DependentAddressSpaceType : public Type, public llvm::FoldingSetNode {
3135	friend class ASTContext;
3136
3137	const ASTContext &Context;
3138	Expr *AddrSpaceExpr;
3139	QualType PointeeType;
3140	SourceLocation loc;
3141
3142	DependentAddressSpaceType(const ASTContext &Context, QualType PointeeType,
3143	QualType can, Expr *AddrSpaceExpr,
3144	SourceLocation loc);
3145
3146	public:
3147	Expr *getAddrSpaceExpr() const { return AddrSpaceExpr; }
3148	QualType getPointeeType() const { return PointeeType; }
3149	SourceLocation getAttributeLoc() const { return loc; }
3150
3151	bool isSugared() const { return false; }
3152	QualType desugar() const { return QualType(this, 0); }
3153
3154	static bool classof(const Type *T) {
3155	return T->getTypeClass() == DependentAddressSpace;
3156	}
3157
3158	void Profile(llvm::FoldingSetNodeID &ID) {
3159	Profile(ID, Context, getPointeeType(), getAddrSpaceExpr());
3160	}
3161
3162	static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
3163	QualType PointeeType, Expr *AddrSpaceExpr);
3164	};
3165
3166	/// Represents an extended vector type where either the type or size is
3167	/// dependent.
3168	///
3169	/// For example:
3170	/// \code
3171	/// template<typename T, int Size>
3172	/// class vector {
3173	/// typedef T __attribute__((ext_vector_type(Size))) type;
3174	/// }
3175	/// \endcode
3176	class DependentSizedExtVectorType : public Type, public llvm::FoldingSetNode {
3177	friend class ASTContext;
3178
3179	const ASTContext &Context;
3180	Expr *SizeExpr;
3181
3182	/// The element type of the array.
3183	QualType ElementType;
3184
3185	SourceLocation loc;
3186
3187	DependentSizedExtVectorType(const ASTContext &Context, QualType ElementType,
3188	QualType can, Expr *SizeExpr, SourceLocation loc);
3189
3190	public:
3191	Expr *getSizeExpr() const { return SizeExpr; }
3192	QualType getElementType() const { return ElementType; }
3193	SourceLocation getAttributeLoc() const { return loc; }
3194
3195	bool isSugared() const { return false; }
3196	QualType desugar() const { return QualType(this, 0); }
3197
3198	static bool classof(const Type *T) {
3199	return T->getTypeClass() == DependentSizedExtVector;
3200	}
3201
3202	void Profile(llvm::FoldingSetNodeID &ID) {
3203	Profile(ID, Context, getElementType(), getSizeExpr());
3204	}
3205
3206	static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
3207	QualType ElementType, Expr *SizeExpr);
3208	};
3209
3210
3211	/// Represents a GCC generic vector type. This type is created using
3212	/// __attribute__((vector_size(n)), where "n" specifies the vector size in
3213	/// bytes; or from an Altivec __vector or vector declaration.
3214	/// Since the constructor takes the number of vector elements, the
3215	/// client is responsible for converting the size into the number of elements.
3216	class VectorType : public Type, public llvm::FoldingSetNode {
3217	public:
3218	enum VectorKind {
3219	/// not a target-specific vector type
3220	GenericVector,
3221
3222	/// is AltiVec vector
3223	AltiVecVector,
3224
3225	/// is AltiVec 'vector Pixel'
3226	AltiVecPixel,
3227
3228	/// is AltiVec 'vector bool ...'
3229	AltiVecBool,
3230
3231	/// is ARM Neon vector
3232	NeonVector,
3233
3234	/// is ARM Neon polynomial vector
3235	NeonPolyVector,
3236
3237	/// is AArch64 SVE fixed-length data vector
3238	SveFixedLengthDataVector,
3239
3240	/// is AArch64 SVE fixed-length predicate vector
3241	SveFixedLengthPredicateVector
3242	};
3243
3244	protected:
3245	friend class ASTContext; // ASTContext creates these.
3246
3247	/// The element type of the vector.
3248	QualType ElementType;
3249
3250	VectorType(QualType vecType, unsigned nElements, QualType canonType,
3251	VectorKind vecKind);
3252
3253	VectorType(TypeClass tc, QualType vecType, unsigned nElements,
3254	QualType canonType, VectorKind vecKind);
3255
3256	public:
3257	QualType getElementType() const { return ElementType; }
3258	unsigned getNumElements() const { return VectorTypeBits.NumElements; }
3259
3260	bool isSugared() const { return false; }
3261	QualType desugar() const { return QualType(this, 0); }
3262
3263	VectorKind getVectorKind() const {
3264	return VectorKind(VectorTypeBits.VecKind);
3265	}
3266
3267	void Profile(llvm::FoldingSetNodeID &ID) {
3268	Profile(ID, getElementType(), getNumElements(),
3269	getTypeClass(), getVectorKind());
3270	}
3271
3272	static void Profile(llvm::FoldingSetNodeID &ID, QualType ElementType,
3273	unsigned NumElements, TypeClass TypeClass,
3274	VectorKind VecKind) {
3275	ID.AddPointer(ElementType.getAsOpaquePtr());
3276	ID.AddInteger(NumElements);
3277	ID.AddInteger(TypeClass);
3278	ID.AddInteger(VecKind);
3279	}
3280
3281	static bool classof(const Type *T) {
3282	return T->getTypeClass() == Vector \|\| T->getTypeClass() == ExtVector;
3283	}
3284	};
3285
3286	/// Represents a vector type where either the type or size is dependent.
3287	////
3288	/// For example:
3289	/// \code
3290	/// template<typename T, int Size>
3291	/// class vector {
3292	/// typedef T __attribute__((vector_size(Size))) type;
3293	/// }
3294	/// \endcode
3295	class DependentVectorType : public Type, public llvm::FoldingSetNode {
3296	friend class ASTContext;
3297
3298	const ASTContext &Context;
3299	QualType ElementType;
3300	Expr *SizeExpr;
3301	SourceLocation Loc;
3302
3303	DependentVectorType(const ASTContext &Context, QualType ElementType,
3304	QualType CanonType, Expr *SizeExpr,
3305	SourceLocation Loc, VectorType::VectorKind vecKind);
3306
3307	public:
3308	Expr *getSizeExpr() const { return SizeExpr; }
3309	QualType getElementType() const { return ElementType; }
3310	SourceLocation getAttributeLoc() const { return Loc; }
3311	VectorType::VectorKind getVectorKind() const {
3312	return VectorType::VectorKind(VectorTypeBits.VecKind);
3313	}
3314
3315	bool isSugared() const { return false; }
3316	QualType desugar() const { return QualType(this, 0); }
3317
3318	static bool classof(const Type *T) {
3319	return T->getTypeClass() == DependentVector;
3320	}
3321
3322	void Profile(llvm::FoldingSetNodeID &ID) {
3323	Profile(ID, Context, getElementType(), getSizeExpr(), getVectorKind());
3324	}
3325
3326	static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
3327	QualType ElementType, const Expr *SizeExpr,
3328	VectorType::VectorKind VecKind);
3329	};
3330
3331	/// ExtVectorType - Extended vector type. This type is created using
3332	/// __attribute__((ext_vector_type(n)), where "n" is the number of elements.
3333	/// Unlike vector_size, ext_vector_type is only allowed on typedef's. This
3334	/// class enables syntactic extensions, like Vector Components for accessing
3335	/// points (as .xyzw), colors (as .rgba), and textures (modeled after OpenGL
3336	/// Shading Language).
3337	class ExtVectorType : public VectorType {
3338	friend class ASTContext; // ASTContext creates these.
3339
3340	ExtVectorType(QualType vecType, unsigned nElements, QualType canonType)
3341	: VectorType(ExtVector, vecType, nElements, canonType, GenericVector) {}
3342
3343	public:
3344	static int getPointAccessorIdx(char c) {
3345	switch (c) {
3346	default: return -1;
3347	case 'x': case 'r': return 0;
3348	case 'y': case 'g': return 1;
3349	case 'z': case 'b': return 2;
3350	case 'w': case 'a': return 3;
3351	}
3352	}
3353
3354	static int getNumericAccessorIdx(char c) {
3355	switch (c) {
3356	default: return -1;
3357	case '0': return 0;
3358	case '1': return 1;
3359	case '2': return 2;
3360	case '3': return 3;
3361	case '4': return 4;
3362	case '5': return 5;
3363	case '6': return 6;
3364	case '7': return 7;
3365	case '8': return 8;
3366	case '9': return 9;
3367	case 'A':
3368	case 'a': return 10;
3369	case 'B':
3370	case 'b': return 11;
3371	case 'C':
3372	case 'c': return 12;
3373	case 'D':
3374	case 'd': return 13;
3375	case 'E':
3376	case 'e': return 14;
3377	case 'F':
3378	case 'f': return 15;
3379	}
3380	}
3381
3382	static int getAccessorIdx(char c, bool isNumericAccessor) {
3383	if (isNumericAccessor)
3384	return getNumericAccessorIdx(c);
3385	else
3386	return getPointAccessorIdx(c);
3387	}
3388
3389	bool isAccessorWithinNumElements(char c, bool isNumericAccessor) const {
3390	if (int idx = getAccessorIdx(c, isNumericAccessor)+1)
3391	return unsigned(idx-1) < getNumElements();
3392	return false;
3393	}
3394
3395	bool isSugared() const { return false; }
3396	QualType desugar() const { return QualType(this, 0); }
3397
3398	static bool classof(const Type *T) {
3399	return T->getTypeClass() == ExtVector;
3400	}
3401	};
3402
3403	/// Represents a matrix type, as defined in the Matrix Types clang extensions.
3404	/// __attribute__((matrix_type(rows, columns))), where "rows" specifies
3405	/// number of rows and "columns" specifies the number of columns.
3406	class MatrixType : public Type, public llvm::FoldingSetNode {
3407	protected:
3408	friend class ASTContext;
3409
3410	/// The element type of the matrix.
3411	QualType ElementType;
3412
3413	MatrixType(QualType ElementTy, QualType CanonElementTy);
3414
3415	MatrixType(TypeClass TypeClass, QualType ElementTy, QualType CanonElementTy,
3416	const Expr RowExpr = nullptr, const Expr ColumnExpr = nullptr);
3417
3418	public:
3419	/// Returns type of the elements being stored in the matrix
3420	QualType getElementType() const { return ElementType; }
3421
3422	/// Valid elements types are the following:
3423	/// * an integer type (as in C2x 6.2.5p19), but excluding enumerated types
3424	/// and _Bool
3425	/// * the standard floating types float or double
3426	/// * a half-precision floating point type, if one is supported on the target
3427	static bool isValidElementType(QualType T) {
3428	return T->isDependentType() \|\|
3429	(T->isRealType() && !T->isBooleanType() && !T->isEnumeralType());
3430	}
3431
3432	bool isSugared() const { return false; }
3433	QualType desugar() const { return QualType(this, 0); }
3434
3435	static bool classof(const Type *T) {
3436	return T->getTypeClass() == ConstantMatrix \|\|
3437	T->getTypeClass() == DependentSizedMatrix;
3438	}
3439	};
3440
3441	/// Represents a concrete matrix type with constant number of rows and columns
3442	class ConstantMatrixType final : public MatrixType {
3443	protected:
3444	friend class ASTContext;
3445
3446	/// The element type of the matrix.
3447	// FIXME: Appears to be unused? There is also MatrixType::ElementType...
3448	QualType ElementType;
3449
3450	/// Number of rows and columns.
3451	unsigned NumRows;
3452	unsigned NumColumns;
3453
3454	static constexpr unsigned MaxElementsPerDimension = (1 << 20) - 1;
3455
3456	ConstantMatrixType(QualType MatrixElementType, unsigned NRows,
3457	unsigned NColumns, QualType CanonElementType);
3458
3459	ConstantMatrixType(TypeClass typeClass, QualType MatrixType, unsigned NRows,
3460	unsigned NColumns, QualType CanonElementType);
3461
3462	public:
3463	/// Returns the number of rows in the matrix.
3464	unsigned getNumRows() const { return NumRows; }
3465
3466	/// Returns the number of columns in the matrix.
3467	unsigned getNumColumns() const { return NumColumns; }
3468
3469	/// Returns the number of elements required to embed the matrix into a vector.
3470	unsigned getNumElementsFlattened() const {
3471	return getNumRows() * getNumColumns();
3472	}
3473
3474	/// Returns true if \p NumElements is a valid matrix dimension.
3475	static constexpr bool isDimensionValid(size_t NumElements) {
3476	return NumElements > 0 && NumElements <= MaxElementsPerDimension;
3477	}
3478
3479	/// Returns the maximum number of elements per dimension.
3480	static constexpr unsigned getMaxElementsPerDimension() {
3481	return MaxElementsPerDimension;
3482	}
3483
3484	void Profile(llvm::FoldingSetNodeID &ID) {
3485	Profile(ID, getElementType(), getNumRows(), getNumColumns(),
3486	getTypeClass());
3487	}
3488
3489	static void Profile(llvm::FoldingSetNodeID &ID, QualType ElementType,
3490	unsigned NumRows, unsigned NumColumns,
3491	TypeClass TypeClass) {
3492	ID.AddPointer(ElementType.getAsOpaquePtr());
3493	ID.AddInteger(NumRows);
3494	ID.AddInteger(NumColumns);
3495	ID.AddInteger(TypeClass);
3496	}
3497
3498	static bool classof(const Type *T) {
3499	return T->getTypeClass() == ConstantMatrix;
3500	}
3501	};
3502
3503	/// Represents a matrix type where the type and the number of rows and columns
3504	/// is dependent on a template.
3505	class DependentSizedMatrixType final : public MatrixType {
3506	friend class ASTContext;
3507
3508	const ASTContext &Context;
3509	Expr *RowExpr;
3510	Expr *ColumnExpr;
3511
3512	SourceLocation loc;
3513
3514	DependentSizedMatrixType(const ASTContext &Context, QualType ElementType,
3515	QualType CanonicalType, Expr *RowExpr,
3516	Expr *ColumnExpr, SourceLocation loc);
3517
3518	public:
3519	QualType getElementType() const { return ElementType; }
3520	Expr *getRowExpr() const { return RowExpr; }
3521	Expr *getColumnExpr() const { return ColumnExpr; }
3522	SourceLocation getAttributeLoc() const { return loc; }
3523
3524	bool isSugared() const { return false; }
3525	QualType desugar() const { return QualType(this, 0); }
3526
3527	static bool classof(const Type *T) {
3528	return T->getTypeClass() == DependentSizedMatrix;
3529	}
3530
3531	void Profile(llvm::FoldingSetNodeID &ID) {
3532	Profile(ID, Context, getElementType(), getRowExpr(), getColumnExpr());
3533	}
3534
3535	static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
3536	QualType ElementType, Expr RowExpr, Expr ColumnExpr);
3537	};
3538
3539	/// FunctionType - C99 6.7.5.3 - Function Declarators. This is the common base
3540	/// class of FunctionNoProtoType and FunctionProtoType.
3541	class FunctionType : public Type {
3542	// The type returned by the function.
3543	QualType ResultType;
3544
3545	public:
3546	/// Interesting information about a specific parameter that can't simply
3547	/// be reflected in parameter's type. This is only used by FunctionProtoType
3548	/// but is in FunctionType to make this class available during the
3549	/// specification of the bases of FunctionProtoType.
3550	///
3551	/// It makes sense to model language features this way when there's some
3552	/// sort of parameter-specific override (such as an attribute) that
3553	/// affects how the function is called. For example, the ARC ns_consumed
3554	/// attribute changes whether a parameter is passed at +0 (the default)
3555	/// or +1 (ns_consumed). This must be reflected in the function type,
3556	/// but isn't really a change to the parameter type.
3557	///
3558	/// One serious disadvantage of modelling language features this way is
3559	/// that they generally do not work with language features that attempt
3560	/// to destructure types. For example, template argument deduction will
3561	/// not be able to match a parameter declared as
3562	/// T (*)(U)
3563	/// against an argument of type
3564	/// void (*)(__attribute__((ns_consumed)) id)
3565	/// because the substitution of T=void, U=id into the former will
3566	/// not produce the latter.
3567	class ExtParameterInfo {
3568	enum {
3569	ABIMask = 0x0F,
3570	IsConsumed = 0x10,
3571	HasPassObjSize = 0x20,
3572	IsNoEscape = 0x40,
3573	};
3574	unsigned char Data = 0;
3575
3576	public:
3577	ExtParameterInfo() = default;
3578
3579	/// Return the ABI treatment of this parameter.
3580	ParameterABI getABI() const { return ParameterABI(Data & ABIMask); }
3581	ExtParameterInfo withABI(ParameterABI kind) const {
3582	ExtParameterInfo copy = *this;
3583	copy.Data = (copy.Data & ~ABIMask) \| unsigned(kind);
3584	return copy;
3585	}
3586
3587	/// Is this parameter considered "consumed" by Objective-C ARC?
3588	/// Consumed parameters must have retainable object type.
3589	bool isConsumed() const { return (Data & IsConsumed); }
3590	ExtParameterInfo withIsConsumed(bool consumed) const {
3591	ExtParameterInfo copy = *this;
3592	if (consumed)
3593	copy.Data \|= IsConsumed;
3594	else
3595	copy.Data &= ~IsConsumed;
3596	return copy;
3597	}
3598
3599	bool hasPassObjectSize() const { return Data & HasPassObjSize; }
3600	ExtParameterInfo withHasPassObjectSize() const {
3601	ExtParameterInfo Copy = *this;
3602	Copy.Data \|= HasPassObjSize;
3603	return Copy;
3604	}
3605
3606	bool isNoEscape() const { return Data & IsNoEscape; }
3607	ExtParameterInfo withIsNoEscape(bool NoEscape) const {
3608	ExtParameterInfo Copy = *this;
3609	if (NoEscape)
3610	Copy.Data \|= IsNoEscape;
3611	else
3612	Copy.Data &= ~IsNoEscape;
3613	return Copy;
3614	}
3615
3616	unsigned char getOpaqueValue() const { return Data; }
3617	static ExtParameterInfo getFromOpaqueValue(unsigned char data) {
3618	ExtParameterInfo result;
3619	result.Data = data;
3620	return result;
3621	}
3622
3623	friend bool operator==(ExtParameterInfo lhs, ExtParameterInfo rhs) {
3624	return lhs.Data == rhs.Data;
3625	}
3626
3627	friend bool operator!=(ExtParameterInfo lhs, ExtParameterInfo rhs) {
3628	return lhs.Data != rhs.Data;
3629	}
3630	};
3631
3632	/// A class which abstracts out some details necessary for
3633	/// making a call.
3634	///
3635	/// It is not actually used directly for storing this information in
3636	/// a FunctionType, although FunctionType does currently use the
3637	/// same bit-pattern.
3638	///
3639	// If you add a field (say Foo), other than the obvious places (both,
3640	// constructors, compile failures), what you need to update is
3641	// * Operator==
3642	// * getFoo
3643	// * withFoo
3644	// * functionType. Add Foo, getFoo.
3645	// * ASTContext::getFooType
3646	// * ASTContext::mergeFunctionTypes
3647	// * FunctionNoProtoType::Profile
3648	// * FunctionProtoType::Profile
3649	// * TypePrinter::PrintFunctionProto
3650	// * AST read and write
3651	// * Codegen
3652	class ExtInfo {
3653	friend class FunctionType;
3654
3655	// Feel free to rearrange or add bits, but if you go over 16, you'll need to
3656	// adjust the Bits field below, and if you add bits, you'll need to adjust
3657	// Type::FunctionTypeBitfields::ExtInfo as well.
3658
3659	// \| CC \|noreturn\|produces\|nocallersavedregs\|regparm\|nocfcheck\|cmsenscall\|
3660	// \|0 .. 4\| 5 \| 6 \| 7 \|8 .. 10\| 11 \| 12 \|
3661	//
3662	// regparm is either 0 (no regparm attribute) or the regparm value+1.
3663	enum { CallConvMask = 0x1F };
3664	enum { NoReturnMask = 0x20 };
3665	enum { ProducesResultMask = 0x40 };
3666	enum { NoCallerSavedRegsMask = 0x80 };
3667	enum {
3668	RegParmMask = 0x700,
3669	RegParmOffset = 8
3670	};
3671	enum { NoCfCheckMask = 0x800 };
3672	enum { CmseNSCallMask = 0x1000 };
3673	uint16_t Bits = CC_C;
3674
3675	ExtInfo(unsigned Bits) : Bits(static_cast<uint16_t>(Bits)) {}
3676
3677	public:
3678	// Constructor with no defaults. Use this when you know that you
3679	// have all the elements (when reading an AST file for example).
3680	ExtInfo(bool noReturn, bool hasRegParm, unsigned regParm, CallingConv cc,
3681	bool producesResult, bool noCallerSavedRegs, bool NoCfCheck,
3682	bool cmseNSCall) {
3683	assert((!hasRegParm \|\| regParm < 7) && "Invalid regparm value")(((!hasRegParm \|\| regParm < 7) && "Invalid regparm value" ) ? static_cast<void> (0) : __assert_fail ("(!hasRegParm \|\| regParm < 7) && \"Invalid regparm value\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 3683, __PRETTY_FUNCTION__));
3684	Bits = ((unsigned)cc) \| (noReturn ? NoReturnMask : 0) \|
3685	(producesResult ? ProducesResultMask : 0) \|
3686	(noCallerSavedRegs ? NoCallerSavedRegsMask : 0) \|
3687	(hasRegParm ? ((regParm + 1) << RegParmOffset) : 0) \|
3688	(NoCfCheck ? NoCfCheckMask : 0) \|
3689	(cmseNSCall ? CmseNSCallMask : 0);
3690	}
3691
3692	// Constructor with all defaults. Use when for example creating a
3693	// function known to use defaults.
3694	ExtInfo() = default;
3695
3696	// Constructor with just the calling convention, which is an important part
3697	// of the canonical type.
3698	ExtInfo(CallingConv CC) : Bits(CC) {}
3699
3700	bool getNoReturn() const { return Bits & NoReturnMask; }
3701	bool getProducesResult() const { return Bits & ProducesResultMask; }
3702	bool getCmseNSCall() const { return Bits & CmseNSCallMask; }
3703	bool getNoCallerSavedRegs() const { return Bits & NoCallerSavedRegsMask; }
3704	bool getNoCfCheck() const { return Bits & NoCfCheckMask; }
3705	bool getHasRegParm() const { return ((Bits & RegParmMask) >> RegParmOffset) != 0; }
3706
3707	unsigned getRegParm() const {
3708	unsigned RegParm = (Bits & RegParmMask) >> RegParmOffset;
3709	if (RegParm > 0)
3710	--RegParm;
3711	return RegParm;
3712	}
3713
3714	CallingConv getCC() const { return CallingConv(Bits & CallConvMask); }
3715
3716	bool operator==(ExtInfo Other) const {
3717	return Bits == Other.Bits;
3718	}
3719	bool operator!=(ExtInfo Other) const {
3720	return Bits != Other.Bits;
3721	}
3722
3723	// Note that we don't have setters. That is by design, use
3724	// the following with methods instead of mutating these objects.
3725
3726	ExtInfo withNoReturn(bool noReturn) const {
3727	if (noReturn)
3728	return ExtInfo(Bits \| NoReturnMask);
3729	else
3730	return ExtInfo(Bits & ~NoReturnMask);
3731	}
3732
3733	ExtInfo withProducesResult(bool producesResult) const {
3734	if (producesResult)
3735	return ExtInfo(Bits \| ProducesResultMask);
3736	else
3737	return ExtInfo(Bits & ~ProducesResultMask);
3738	}
3739
3740	ExtInfo withCmseNSCall(bool cmseNSCall) const {
3741	if (cmseNSCall)
3742	return ExtInfo(Bits \| CmseNSCallMask);
3743	else
3744	return ExtInfo(Bits & ~CmseNSCallMask);
3745	}
3746
3747	ExtInfo withNoCallerSavedRegs(bool noCallerSavedRegs) const {
3748	if (noCallerSavedRegs)
3749	return ExtInfo(Bits \| NoCallerSavedRegsMask);
3750	else
3751	return ExtInfo(Bits & ~NoCallerSavedRegsMask);
3752	}
3753
3754	ExtInfo withNoCfCheck(bool noCfCheck) const {
3755	if (noCfCheck)
3756	return ExtInfo(Bits \| NoCfCheckMask);
3757	else
3758	return ExtInfo(Bits & ~NoCfCheckMask);
3759	}
3760
3761	ExtInfo withRegParm(unsigned RegParm) const {
3762	assert(RegParm < 7 && "Invalid regparm value")((RegParm < 7 && "Invalid regparm value") ? static_cast <void> (0) : __assert_fail ("RegParm < 7 && \"Invalid regparm value\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 3762, __PRETTY_FUNCTION__));
3763	return ExtInfo((Bits & ~RegParmMask) \|
3764	((RegParm + 1) << RegParmOffset));
3765	}
3766
3767	ExtInfo withCallingConv(CallingConv cc) const {
3768	return ExtInfo((Bits & ~CallConvMask) \| (unsigned) cc);
3769	}
3770
3771	void Profile(llvm::FoldingSetNodeID &ID) const {
3772	ID.AddInteger(Bits);
3773	}
3774	};
3775
3776	/// A simple holder for a QualType representing a type in an
3777	/// exception specification. Unfortunately needed by FunctionProtoType
3778	/// because TrailingObjects cannot handle repeated types.
3779	struct ExceptionType { QualType Type; };
3780
3781	/// A simple holder for various uncommon bits which do not fit in
3782	/// FunctionTypeBitfields. Aligned to alignof(void *) to maintain the
3783	/// alignment of subsequent objects in TrailingObjects. You must update
3784	/// hasExtraBitfields in FunctionProtoType after adding extra data here.
3785	struct alignas(void *) FunctionTypeExtraBitfields {
3786	/// The number of types in the exception specification.
3787	/// A whole unsigned is not needed here and according to
3788	/// [implimits] 8 bits would be enough here.
3789	unsigned NumExceptionType;
3790	};
3791
3792	protected:
3793	FunctionType(TypeClass tc, QualType res, QualType Canonical,
3794	TypeDependence Dependence, ExtInfo Info)
3795	: Type(tc, Canonical, Dependence), ResultType(res) {
3796	FunctionTypeBits.ExtInfo = Info.Bits;
3797	}
3798
3799	Qualifiers getFastTypeQuals() const {
3800	return Qualifiers::fromFastMask(FunctionTypeBits.FastTypeQuals);
3801	}
3802
3803	public:
3804	QualType getReturnType() const { return ResultType; }
3805
3806	bool getHasRegParm() const { return getExtInfo().getHasRegParm(); }
3807	unsigned getRegParmType() const { return getExtInfo().getRegParm(); }
3808
3809	/// Determine whether this function type includes the GNU noreturn
3810	/// attribute. The C++11 [[noreturn]] attribute does not affect the function
3811	/// type.
3812	bool getNoReturnAttr() const { return getExtInfo().getNoReturn(); }
3813
3814	bool getCmseNSCallAttr() const { return getExtInfo().getCmseNSCall(); }
3815	CallingConv getCallConv() const { return getExtInfo().getCC(); }
3816	ExtInfo getExtInfo() const { return ExtInfo(FunctionTypeBits.ExtInfo); }
3817
3818	static_assert((~Qualifiers::FastMask & Qualifiers::CVRMask) == 0,
3819	"Const, volatile and restrict are assumed to be a subset of "
3820	"the fast qualifiers.");
3821
3822	bool isConst() const { return getFastTypeQuals().hasConst(); }
3823	bool isVolatile() const { return getFastTypeQuals().hasVolatile(); }
3824	bool isRestrict() const { return getFastTypeQuals().hasRestrict(); }
3825
3826	/// Determine the type of an expression that calls a function of
3827	/// this type.
3828	QualType getCallResultType(const ASTContext &Context) const {
3829	return getReturnType().getNonLValueExprType(Context);
3830	}
3831
3832	static StringRef getNameForCallConv(CallingConv CC);
3833
3834	static bool classof(const Type *T) {
3835	return T->getTypeClass() == FunctionNoProto \|\|
3836	T->getTypeClass() == FunctionProto;
3837	}
3838	};
3839
3840	/// Represents a K&R-style 'int foo()' function, which has
3841	/// no information available about its arguments.
3842	class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
3843	friend class ASTContext; // ASTContext creates these.
3844
3845	FunctionNoProtoType(QualType Result, QualType Canonical, ExtInfo Info)
3846	: FunctionType(FunctionNoProto, Result, Canonical,
3847	Result->getDependence() &
3848	~(TypeDependence::DependentInstantiation \|
3849	TypeDependence::UnexpandedPack),
3850	Info) {}
3851
3852	public:
3853	// No additional state past what FunctionType provides.
3854
3855	bool isSugared() const { return false; }
3856	QualType desugar() const { return QualType(this, 0); }
3857
3858	void Profile(llvm::FoldingSetNodeID &ID) {
3859	Profile(ID, getReturnType(), getExtInfo());
3860	}
3861
3862	static void Profile(llvm::FoldingSetNodeID &ID, QualType ResultType,
3863	ExtInfo Info) {
3864	Info.Profile(ID);
3865	ID.AddPointer(ResultType.getAsOpaquePtr());
3866	}
3867
3868	static bool classof(const Type *T) {
3869	return T->getTypeClass() == FunctionNoProto;
3870	}
3871	};
3872
3873	/// Represents a prototype with parameter type info, e.g.
3874	/// 'int foo(int)' or 'int foo(void)'. 'void' is represented as having no
3875	/// parameters, not as having a single void parameter. Such a type can have
3876	/// an exception specification, but this specification is not part of the
3877	/// canonical type. FunctionProtoType has several trailing objects, some of
3878	/// which optional. For more information about the trailing objects see
3879	/// the first comment inside FunctionProtoType.
3880	class FunctionProtoType final
3881	: public FunctionType,
3882	public llvm::FoldingSetNode,
3883	private llvm::TrailingObjects<
3884	FunctionProtoType, QualType, SourceLocation,
3885	FunctionType::FunctionTypeExtraBitfields, FunctionType::ExceptionType,
3886	Expr , FunctionDecl , FunctionType::ExtParameterInfo, Qualifiers> {
3887	friend class ASTContext; // ASTContext creates these.
3888	friend TrailingObjects;
3889
3890	// FunctionProtoType is followed by several trailing objects, some of
3891	// which optional. They are in order:
3892	//
3893	// * An array of getNumParams() QualType holding the parameter types.
3894	// Always present. Note that for the vast majority of FunctionProtoType,
3895	// these will be the only trailing objects.
3896	//
3897	// * Optionally if the function is variadic, the SourceLocation of the
3898	// ellipsis.
3899	//
3900	// * Optionally if some extra data is stored in FunctionTypeExtraBitfields
3901	// (see FunctionTypeExtraBitfields and FunctionTypeBitfields):
3902	// a single FunctionTypeExtraBitfields. Present if and only if
3903	// hasExtraBitfields() is true.
3904	//
3905	// * Optionally exactly one of:
3906	// * an array of getNumExceptions() ExceptionType,
3907	// * a single Expr *,
3908	// * a pair of FunctionDecl *,
3909	// * a single FunctionDecl *
3910	// used to store information about the various types of exception
3911	// specification. See getExceptionSpecSize for the details.
3912	//
3913	// * Optionally an array of getNumParams() ExtParameterInfo holding
3914	// an ExtParameterInfo for each of the parameters. Present if and
3915	// only if hasExtParameterInfos() is true.
3916	//
3917	// * Optionally a Qualifiers object to represent extra qualifiers that can't
3918	// be represented by FunctionTypeBitfields.FastTypeQuals. Present if and only
3919	// if hasExtQualifiers() is true.
3920	//
3921	// The optional FunctionTypeExtraBitfields has to be before the data
3922	// related to the exception specification since it contains the number
3923	// of exception types.
3924	//
3925	// We put the ExtParameterInfos last. If all were equal, it would make
3926	// more sense to put these before the exception specification, because
3927	// it's much easier to skip past them compared to the elaborate switch
3928	// required to skip the exception specification. However, all is not
3929	// equal; ExtParameterInfos are used to model very uncommon features,
3930	// and it's better not to burden the more common paths.
3931
3932	public:
3933	/// Holds information about the various types of exception specification.
3934	/// ExceptionSpecInfo is not stored as such in FunctionProtoType but is
3935	/// used to group together the various bits of information about the
3936	/// exception specification.
3937	struct ExceptionSpecInfo {
3938	/// The kind of exception specification this is.
3939	ExceptionSpecificationType Type = EST_None;
3940
3941	/// Explicitly-specified list of exception types.
3942	ArrayRef<QualType> Exceptions;
3943
3944	/// Noexcept expression, if this is a computed noexcept specification.
3945	Expr *NoexceptExpr = nullptr;
3946
3947	/// The function whose exception specification this is, for
3948	/// EST_Unevaluated and EST_Uninstantiated.
3949	FunctionDecl *SourceDecl = nullptr;
3950
3951	/// The function template whose exception specification this is instantiated
3952	/// from, for EST_Uninstantiated.
3953	FunctionDecl *SourceTemplate = nullptr;
3954
3955	ExceptionSpecInfo() = default;
3956
3957	ExceptionSpecInfo(ExceptionSpecificationType EST) : Type(EST) {}
3958	};
3959
3960	/// Extra information about a function prototype. ExtProtoInfo is not
3961	/// stored as such in FunctionProtoType but is used to group together
3962	/// the various bits of extra information about a function prototype.
3963	struct ExtProtoInfo {
3964	FunctionType::ExtInfo ExtInfo;
3965	bool Variadic : 1;
3966	bool HasTrailingReturn : 1;
3967	Qualifiers TypeQuals;
3968	RefQualifierKind RefQualifier = RQ_None;
3969	ExceptionSpecInfo ExceptionSpec;
3970	const ExtParameterInfo *ExtParameterInfos = nullptr;
3971	SourceLocation EllipsisLoc;
3972
3973	ExtProtoInfo() : Variadic(false), HasTrailingReturn(false) {}
3974
3975	ExtProtoInfo(CallingConv CC)
3976	: ExtInfo(CC), Variadic(false), HasTrailingReturn(false) {}
3977
3978	ExtProtoInfo withExceptionSpec(const ExceptionSpecInfo &ESI) {
3979	ExtProtoInfo Result(*this);
3980	Result.ExceptionSpec = ESI;
3981	return Result;
3982	}
3983	};
3984
3985	private:
3986	unsigned numTrailingObjects(OverloadToken<QualType>) const {
3987	return getNumParams();
3988	}
3989
3990	unsigned numTrailingObjects(OverloadToken<SourceLocation>) const {
3991	return isVariadic();
3992	}
3993
3994	unsigned numTrailingObjects(OverloadToken<FunctionTypeExtraBitfields>) const {
3995	return hasExtraBitfields();
3996	}
3997
3998	unsigned numTrailingObjects(OverloadToken<ExceptionType>) const {
3999	return getExceptionSpecSize().NumExceptionType;
4000	}
4001
4002	unsigned numTrailingObjects(OverloadToken<Expr *>) const {
4003	return getExceptionSpecSize().NumExprPtr;
4004	}
4005
4006	unsigned numTrailingObjects(OverloadToken<FunctionDecl *>) const {
4007	return getExceptionSpecSize().NumFunctionDeclPtr;
4008	}
4009
4010	unsigned numTrailingObjects(OverloadToken<ExtParameterInfo>) const {
4011	return hasExtParameterInfos() ? getNumParams() : 0;
4012	}
4013
4014	/// Determine whether there are any argument types that
4015	/// contain an unexpanded parameter pack.
4016	static bool containsAnyUnexpandedParameterPack(const QualType *ArgArray,
4017	unsigned numArgs) {
4018	for (unsigned Idx = 0; Idx < numArgs; ++Idx)
4019	if (ArgArray[Idx]->containsUnexpandedParameterPack())
4020	return true;
4021
4022	return false;
4023	}
4024
4025	FunctionProtoType(QualType result, ArrayRef<QualType> params,
4026	QualType canonical, const ExtProtoInfo &epi);
4027
4028	/// This struct is returned by getExceptionSpecSize and is used to
4029	/// translate an ExceptionSpecificationType to the number and kind
4030	/// of trailing objects related to the exception specification.
4031	struct ExceptionSpecSizeHolder {
4032	unsigned NumExceptionType;
4033	unsigned NumExprPtr;
4034	unsigned NumFunctionDeclPtr;
4035	};
4036
4037	/// Return the number and kind of trailing objects
4038	/// related to the exception specification.
4039	static ExceptionSpecSizeHolder
4040	getExceptionSpecSize(ExceptionSpecificationType EST, unsigned NumExceptions) {
4041	switch (EST) {
4042	case EST_None:
4043	case EST_DynamicNone:
4044	case EST_MSAny:
4045	case EST_BasicNoexcept:
4046	case EST_Unparsed:
4047	case EST_NoThrow:
4048	return {0, 0, 0};
4049
4050	case EST_Dynamic:
4051	return {NumExceptions, 0, 0};
4052
4053	case EST_DependentNoexcept:
4054	case EST_NoexceptFalse:
4055	case EST_NoexceptTrue:
4056	return {0, 1, 0};
4057
4058	case EST_Uninstantiated:
4059	return {0, 0, 2};
4060
4061	case EST_Unevaluated:
4062	return {0, 0, 1};
4063	}
4064	llvm_unreachable("bad exception specification kind")::llvm::llvm_unreachable_internal("bad exception specification kind" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 4064);
4065	}
4066
4067	/// Return the number and kind of trailing objects
4068	/// related to the exception specification.
4069	ExceptionSpecSizeHolder getExceptionSpecSize() const {
4070	return getExceptionSpecSize(getExceptionSpecType(), getNumExceptions());
4071	}
4072
4073	/// Whether the trailing FunctionTypeExtraBitfields is present.
4074	static bool hasExtraBitfields(ExceptionSpecificationType EST) {
4075	// If the exception spec type is EST_Dynamic then we have > 0 exception
4076	// types and the exact number is stored in FunctionTypeExtraBitfields.
4077	return EST == EST_Dynamic;
4078	}
4079
4080	/// Whether the trailing FunctionTypeExtraBitfields is present.
4081	bool hasExtraBitfields() const {
4082	return hasExtraBitfields(getExceptionSpecType());
4083	}
4084
4085	bool hasExtQualifiers() const {
4086	return FunctionTypeBits.HasExtQuals;
4087	}
4088
4089	public:
4090	unsigned getNumParams() const { return FunctionTypeBits.NumParams; }
4091
4092	QualType getParamType(unsigned i) const {
4093	assert(i < getNumParams() && "invalid parameter index")((i < getNumParams() && "invalid parameter index") ? static_cast<void> (0) : __assert_fail ("i < getNumParams() && \"invalid parameter index\"" , "/build/llvm-toolchain-snapshot-13~++20210405022414+5f57793c4fe4/clang/include/clang/AST/Type.h" , 4093, __PRETTY_FUNCTION__));
4094	return param_type_begin()[i];
4095	}
4096
4097	ArrayRef<QualType> getParamTypes() const {
4098	return llvm::makeArrayRef(param_type_begin(), param_type_end());
4099	}
4100
4101	ExtProtoInfo getExtProtoInfo() const {
4102	ExtProtoInfo EPI;
4103	EPI.ExtInfo = getExtInfo();
4104	EPI.Variadic = isVariadic();
4105	EPI.EllipsisLoc = getEllipsisLoc();
4106	EPI.HasTrailingReturn = hasTrailingReturn();
4107	EPI.ExceptionSpec = getExceptionSpecInfo();
4108	EPI.TypeQuals = getMethodQuals();
4109	EPI.RefQualifier = getRefQualifier();
4110	EPI.ExtParameterInfos = getExtParameterInfosOrNull();
4111	return EPI;
4112	}
4113
4114	/// Get the kind of exception specification on this function.
4115	ExceptionSpecificationType getExceptionSpecType() const {
4116	return static_cast<ExceptionSpecificationType>(
4117	FunctionTypeBits.ExceptionSpecType);
4118	}
4119
4120	/// Return whether this function has any kind of exception spec.
4121	bool hasExceptionSpec() const { return getExceptionSpecType() != EST_None; }
4122
4123	/// Return whether this function has a dynamic (throw) exception spec.
4124	bool hasDynamicExceptionSpec() const {
4125	return isDynamicExceptionSpec(getExceptionSpecType());
4126	}
4127
4128	/// Return whether this function has a noexcept exception spec.
4129	bool hasNoexceptExceptionSpec() const {
4130	return isNoexceptExceptionSpec(getExceptionSpecType());
4131	}
4132
4133	/// Return whether this function has a dependent exception spec.
4134	bool hasDependentExceptionSpec() const;
4135
4136	/// Return whether this function has an instantiation-dependent exception
4137	/// spec.
4138	bool hasInstantiationDependentExceptionSpec()