Bug Summary

File:build/source/clang-tools-extra/clangd/AST.cpp
Warning:line 747, column 14
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 -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name AST.cpp -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 -mframe-pointer=none -relaxed-aliasing -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/source/build-llvm/tools/clang/stage2-bins -resource-dir /usr/lib/llvm-17/lib/clang/17 -D CLANG_REPOSITORY_STRING="++20230327111513+c3ee525e0295-1~exp1~20230327111622.1189" -D _DEBUG -D _GLIBCXX_ASSERTIONS -D _GNU_SOURCE -D _LIBCPP_ENABLE_ASSERTIONS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I tools/clang/tools/extra/clangd -I /build/source/clang-tools-extra/clangd -I /build/source/clang-tools-extra/clangd/../include-cleaner/include -I tools/clang/tools/extra/clangd/../clang-tidy -I /build/source/clang/include -I tools/clang/include -I include -I /build/source/llvm/include -I /build/source/clang-tools-extra/pseudo/lib/../include -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-17/lib/clang/17/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fmacro-prefix-map=/build/source/= -fcoverage-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fcoverage-prefix-map=/build/source/= -source-date-epoch 1679915782 -O2 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -Wno-misleading-indentation -std=c++17 -fdeprecated-macro -fdebug-compilation-dir=/build/source/build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/source/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -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-2023-03-27-130437-16335-1 -x c++ /build/source/clang-tools-extra/clangd/AST.cpp
1//===--- AST.cpp - Utility AST functions -----------------------*- 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#include "AST.h"
10
11#include "SourceCode.h"
12#include "clang/AST/ASTContext.h"
13#include "clang/AST/ASTTypeTraits.h"
14#include "clang/AST/Decl.h"
15#include "clang/AST/DeclBase.h"
16#include "clang/AST/DeclCXX.h"
17#include "clang/AST/DeclObjC.h"
18#include "clang/AST/DeclTemplate.h"
19#include "clang/AST/DeclarationName.h"
20#include "clang/AST/ExprCXX.h"
21#include "clang/AST/NestedNameSpecifier.h"
22#include "clang/AST/PrettyPrinter.h"
23#include "clang/AST/RecursiveASTVisitor.h"
24#include "clang/AST/Stmt.h"
25#include "clang/AST/TemplateBase.h"
26#include "clang/AST/TypeLoc.h"
27#include "clang/Basic/Builtins.h"
28#include "clang/Basic/SourceLocation.h"
29#include "clang/Basic/SourceManager.h"
30#include "clang/Basic/Specifiers.h"
31#include "clang/Index/USRGeneration.h"
32#include "llvm/ADT/ArrayRef.h"
33#include "llvm/ADT/STLExtras.h"
34#include "llvm/ADT/SmallSet.h"
35#include "llvm/ADT/StringRef.h"
36#include "llvm/Support/Casting.h"
37#include "llvm/Support/raw_ostream.h"
38#include <iterator>
39#include <optional>
40#include <string>
41#include <vector>
42
43namespace clang {
44namespace clangd {
45
46namespace {
47std::optional<llvm::ArrayRef<TemplateArgumentLoc>>
48getTemplateSpecializationArgLocs(const NamedDecl &ND) {
49 if (auto *Func = llvm::dyn_cast<FunctionDecl>(&ND)) {
50 if (const ASTTemplateArgumentListInfo *Args =
51 Func->getTemplateSpecializationArgsAsWritten())
52 return Args->arguments();
53 } else if (auto *Cls =
54 llvm::dyn_cast<ClassTemplatePartialSpecializationDecl>(&ND)) {
55 if (auto *Args = Cls->getTemplateArgsAsWritten())
56 return Args->arguments();
57 } else if (auto *Var =
58 llvm::dyn_cast<VarTemplatePartialSpecializationDecl>(&ND)) {
59 if (auto *Args = Var->getTemplateArgsAsWritten())
60 return Args->arguments();
61 } else if (auto *Var = llvm::dyn_cast<VarTemplateSpecializationDecl>(&ND)) {
62 if (auto *Args = Var->getTemplateArgsInfo())
63 return Args->arguments();
64 }
65 // We return std::nullopt for ClassTemplateSpecializationDecls because it does
66 // not contain TemplateArgumentLoc information.
67 return std::nullopt;
68}
69
70template <class T>
71bool isTemplateSpecializationKind(const NamedDecl *D,
72 TemplateSpecializationKind Kind) {
73 if (const auto *TD = dyn_cast<T>(D))
74 return TD->getTemplateSpecializationKind() == Kind;
75 return false;
76}
77
78bool isTemplateSpecializationKind(const NamedDecl *D,
79 TemplateSpecializationKind Kind) {
80 return isTemplateSpecializationKind<FunctionDecl>(D, Kind) ||
81 isTemplateSpecializationKind<CXXRecordDecl>(D, Kind) ||
82 isTemplateSpecializationKind<VarDecl>(D, Kind);
83}
84
85// Store all UsingDirectiveDecls in parent contexts of DestContext, that were
86// introduced before InsertionPoint.
87llvm::DenseSet<const NamespaceDecl *>
88getUsingNamespaceDirectives(const DeclContext *DestContext,
89 SourceLocation Until) {
90 const auto &SM = DestContext->getParentASTContext().getSourceManager();
91 llvm::DenseSet<const NamespaceDecl *> VisibleNamespaceDecls;
92 for (const auto *DC = DestContext; DC; DC = DC->getLookupParent()) {
93 for (const auto *D : DC->decls()) {
94 if (!SM.isWrittenInSameFile(D->getLocation(), Until) ||
95 !SM.isBeforeInTranslationUnit(D->getLocation(), Until))
96 continue;
97 if (auto *UDD = llvm::dyn_cast<UsingDirectiveDecl>(D))
98 VisibleNamespaceDecls.insert(
99 UDD->getNominatedNamespace()->getCanonicalDecl());
100 }
101 }
102 return VisibleNamespaceDecls;
103}
104
105// Goes over all parents of SourceContext until we find a common ancestor for
106// DestContext and SourceContext. Any qualifier including and above common
107// ancestor is redundant, therefore we stop at lowest common ancestor.
108// In addition to that stops early whenever IsVisible returns true. This can be
109// used to implement support for "using namespace" decls.
110std::string
111getQualification(ASTContext &Context, const DeclContext *DestContext,
112 const DeclContext *SourceContext,
113 llvm::function_ref<bool(NestedNameSpecifier *)> IsVisible) {
114 std::vector<const NestedNameSpecifier *> Parents;
115 bool ReachedNS = false;
116 for (const DeclContext *CurContext = SourceContext; CurContext;
117 CurContext = CurContext->getLookupParent()) {
118 // Stop once we reach a common ancestor.
119 if (CurContext->Encloses(DestContext))
120 break;
121
122 NestedNameSpecifier *NNS = nullptr;
123 if (auto *TD = llvm::dyn_cast<TagDecl>(CurContext)) {
124 // There can't be any more tag parents after hitting a namespace.
125 assert(!ReachedNS)(static_cast <bool> (!ReachedNS) ? void (0) : __assert_fail
("!ReachedNS", "clang-tools-extra/clangd/AST.cpp", 125, __extension__
__PRETTY_FUNCTION__));
126 (void)ReachedNS;
127 NNS = NestedNameSpecifier::Create(Context, nullptr, false,
128 TD->getTypeForDecl());
129 } else if (auto *NSD = llvm::dyn_cast<NamespaceDecl>(CurContext)) {
130 ReachedNS = true;
131 NNS = NestedNameSpecifier::Create(Context, nullptr, NSD);
132 // Anonymous and inline namespace names are not spelled while qualifying
133 // a name, so skip those.
134 if (NSD->isAnonymousNamespace() || NSD->isInlineNamespace())
135 continue;
136 } else {
137 // Other types of contexts cannot be spelled in code, just skip over
138 // them.
139 continue;
140 }
141 // Stop if this namespace is already visible at DestContext.
142 if (IsVisible(NNS))
143 break;
144
145 Parents.push_back(NNS);
146 }
147
148 // Go over name-specifiers in reverse order to create necessary qualification,
149 // since we stored inner-most parent first.
150 std::string Result;
151 llvm::raw_string_ostream OS(Result);
152 for (const auto *Parent : llvm::reverse(Parents))
153 Parent->print(OS, Context.getPrintingPolicy());
154 return OS.str();
155}
156
157} // namespace
158
159bool isImplicitTemplateInstantiation(const NamedDecl *D) {
160 return isTemplateSpecializationKind(D, TSK_ImplicitInstantiation);
161}
162
163bool isExplicitTemplateSpecialization(const NamedDecl *D) {
164 return isTemplateSpecializationKind(D, TSK_ExplicitSpecialization);
165}
166
167bool isImplementationDetail(const Decl *D) {
168 return !isSpelledInSource(D->getLocation(),
169 D->getASTContext().getSourceManager());
170}
171
172SourceLocation nameLocation(const clang::Decl &D, const SourceManager &SM) {
173 auto L = D.getLocation();
174 // For `- (void)foo` we want `foo` not the `-`.
175 if (const auto *MD = dyn_cast<ObjCMethodDecl>(&D))
176 L = MD->getSelectorStartLoc();
177 if (isSpelledInSource(L, SM))
178 return SM.getSpellingLoc(L);
179 return SM.getExpansionLoc(L);
180}
181
182std::string printQualifiedName(const NamedDecl &ND) {
183 std::string QName;
184 llvm::raw_string_ostream OS(QName);
185 PrintingPolicy Policy(ND.getASTContext().getLangOpts());
186 // Note that inline namespaces are treated as transparent scopes. This
187 // reflects the way they're most commonly used for lookup. Ideally we'd
188 // include them, but at query time it's hard to find all the inline
189 // namespaces to query: the preamble doesn't have a dedicated list.
190 Policy.SuppressUnwrittenScope = true;
191 // (unnamed struct), not (unnamed struct at /path/to/foo.cc:42:1).
192 // In clangd, context is usually available and paths are mostly noise.
193 Policy.AnonymousTagLocations = false;
194 ND.printQualifiedName(OS, Policy);
195 OS.flush();
196 assert(!StringRef(QName).startswith("::"))(static_cast <bool> (!StringRef(QName).startswith("::")
) ? void (0) : __assert_fail ("!StringRef(QName).startswith(\"::\")"
, "clang-tools-extra/clangd/AST.cpp", 196, __extension__ __PRETTY_FUNCTION__
));
197 return QName;
198}
199
200static bool isAnonymous(const DeclarationName &N) {
201 return N.isIdentifier() && !N.getAsIdentifierInfo();
202}
203
204NestedNameSpecifierLoc getQualifierLoc(const NamedDecl &ND) {
205 if (auto *V = llvm::dyn_cast<DeclaratorDecl>(&ND))
206 return V->getQualifierLoc();
207 if (auto *T = llvm::dyn_cast<TagDecl>(&ND))
208 return T->getQualifierLoc();
209 return NestedNameSpecifierLoc();
210}
211
212std::string printUsingNamespaceName(const ASTContext &Ctx,
213 const UsingDirectiveDecl &D) {
214 PrintingPolicy PP(Ctx.getLangOpts());
215 std::string Name;
216 llvm::raw_string_ostream Out(Name);
217
218 if (auto *Qual = D.getQualifier())
219 Qual->print(Out, PP);
220 D.getNominatedNamespaceAsWritten()->printName(Out);
221 return Out.str();
222}
223
224std::string printName(const ASTContext &Ctx, const NamedDecl &ND) {
225 std::string Name;
226 llvm::raw_string_ostream Out(Name);
227 PrintingPolicy PP(Ctx.getLangOpts());
228 // We don't consider a class template's args part of the constructor name.
229 PP.SuppressTemplateArgsInCXXConstructors = true;
230
231 // Handle 'using namespace'. They all have the same name - <using-directive>.
232 if (auto *UD = llvm::dyn_cast<UsingDirectiveDecl>(&ND)) {
233 Out << "using namespace ";
234 if (auto *Qual = UD->getQualifier())
235 Qual->print(Out, PP);
236 UD->getNominatedNamespaceAsWritten()->printName(Out);
237 return Out.str();
238 }
239
240 if (isAnonymous(ND.getDeclName())) {
241 // Come up with a presentation for an anonymous entity.
242 if (isa<NamespaceDecl>(ND))
243 return "(anonymous namespace)";
244 if (auto *Cls = llvm::dyn_cast<RecordDecl>(&ND)) {
245 if (Cls->isLambda())
246 return "(lambda)";
247 return ("(anonymous " + Cls->getKindName() + ")").str();
248 }
249 if (isa<EnumDecl>(ND))
250 return "(anonymous enum)";
251 return "(anonymous)";
252 }
253
254 // Print nested name qualifier if it was written in the source code.
255 if (auto *Qualifier = getQualifierLoc(ND).getNestedNameSpecifier())
256 Qualifier->print(Out, PP);
257 // Print the name itself.
258 ND.getDeclName().print(Out, PP);
259 // Print template arguments.
260 Out << printTemplateSpecializationArgs(ND);
261
262 return Out.str();
263}
264
265std::string printTemplateSpecializationArgs(const NamedDecl &ND) {
266 std::string TemplateArgs;
267 llvm::raw_string_ostream OS(TemplateArgs);
268 PrintingPolicy Policy(ND.getASTContext().getLangOpts());
269 if (std::optional<llvm::ArrayRef<TemplateArgumentLoc>> Args =
270 getTemplateSpecializationArgLocs(ND)) {
271 printTemplateArgumentList(OS, *Args, Policy);
272 } else if (auto *Cls = llvm::dyn_cast<ClassTemplateSpecializationDecl>(&ND)) {
273 if (const TypeSourceInfo *TSI = Cls->getTypeAsWritten()) {
274 // ClassTemplateSpecializationDecls do not contain
275 // TemplateArgumentTypeLocs, they only have TemplateArgumentTypes. So we
276 // create a new argument location list from TypeSourceInfo.
277 auto STL = TSI->getTypeLoc().getAs<TemplateSpecializationTypeLoc>();
278 llvm::SmallVector<TemplateArgumentLoc> ArgLocs;
279 ArgLocs.reserve(STL.getNumArgs());
280 for (unsigned I = 0; I < STL.getNumArgs(); ++I)
281 ArgLocs.push_back(STL.getArgLoc(I));
282 printTemplateArgumentList(OS, ArgLocs, Policy);
283 } else {
284 // FIXME: Fix cases when getTypeAsWritten returns null inside clang AST,
285 // e.g. friend decls. Currently we fallback to Template Arguments without
286 // location information.
287 printTemplateArgumentList(OS, Cls->getTemplateArgs().asArray(), Policy);
288 }
289 }
290 OS.flush();
291 return TemplateArgs;
292}
293
294std::string printNamespaceScope(const DeclContext &DC) {
295 for (const auto *Ctx = &DC; Ctx != nullptr; Ctx = Ctx->getParent())
296 if (const auto *NS = dyn_cast<NamespaceDecl>(Ctx))
297 if (!NS->isAnonymousNamespace() && !NS->isInlineNamespace())
298 return printQualifiedName(*NS) + "::";
299 return "";
300}
301
302static llvm::StringRef
303getNameOrErrForObjCInterface(const ObjCInterfaceDecl *ID) {
304 return ID ? ID->getName() : "<<error-type>>";
305}
306
307std::string printObjCMethod(const ObjCMethodDecl &Method) {
308 std::string Name;
309 llvm::raw_string_ostream OS(Name);
310
311 OS << (Method.isInstanceMethod() ? '-' : '+') << '[';
312
313 // Should always be true.
314 if (const ObjCContainerDecl *C =
315 dyn_cast<ObjCContainerDecl>(Method.getDeclContext()))
316 OS << printObjCContainer(*C);
317
318 Method.getSelector().print(OS << ' ');
319 if (Method.isVariadic())
320 OS << ", ...";
321
322 OS << ']';
323 OS.flush();
324 return Name;
325}
326
327std::string printObjCContainer(const ObjCContainerDecl &C) {
328 if (const ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(&C)) {
329 std::string Name;
330 llvm::raw_string_ostream OS(Name);
331 const ObjCInterfaceDecl *Class = Category->getClassInterface();
332 OS << getNameOrErrForObjCInterface(Class) << '(' << Category->getName()
333 << ')';
334 OS.flush();
335 return Name;
336 }
337 if (const ObjCCategoryImplDecl *CID = dyn_cast<ObjCCategoryImplDecl>(&C)) {
338 std::string Name;
339 llvm::raw_string_ostream OS(Name);
340 const ObjCInterfaceDecl *Class = CID->getClassInterface();
341 OS << getNameOrErrForObjCInterface(Class) << '(' << CID->getName() << ')';
342 OS.flush();
343 return Name;
344 }
345 return C.getNameAsString();
346}
347
348SymbolID getSymbolID(const Decl *D) {
349 llvm::SmallString<128> USR;
350 if (index::generateUSRForDecl(D, USR))
351 return {};
352 return SymbolID(USR);
353}
354
355SymbolID getSymbolID(const llvm::StringRef MacroName, const MacroInfo *MI,
356 const SourceManager &SM) {
357 if (MI == nullptr)
358 return {};
359 llvm::SmallString<128> USR;
360 if (index::generateUSRForMacro(MacroName, MI->getDefinitionLoc(), SM, USR))
361 return {};
362 return SymbolID(USR);
363}
364
365const ObjCImplDecl *getCorrespondingObjCImpl(const ObjCContainerDecl *D) {
366 if (const auto *ID = dyn_cast<ObjCInterfaceDecl>(D))
367 return ID->getImplementation();
368 if (const auto *CD = dyn_cast<ObjCCategoryDecl>(D)) {
369 if (CD->IsClassExtension()) {
370 if (const auto *ID = CD->getClassInterface())
371 return ID->getImplementation();
372 return nullptr;
373 }
374 return CD->getImplementation();
375 }
376 return nullptr;
377}
378
379Symbol::IncludeDirective
380preferredIncludeDirective(llvm::StringRef FileName, const LangOptions &LangOpts,
381 ArrayRef<Inclusion> MainFileIncludes,
382 ArrayRef<const Decl *> TopLevelDecls) {
383 // Always prefer #include for non-ObjC code.
384 if (!LangOpts.ObjC)
385 return Symbol::IncludeDirective::Include;
386 // If this is not a header file and has ObjC set as the language, prefer
387 // #import.
388 if (!isHeaderFile(FileName, LangOpts))
389 return Symbol::IncludeDirective::Import;
390
391 // Headers lack proper compile flags most of the time, so we might treat a
392 // header as ObjC accidentally. Perform some extra checks to make sure this
393 // works.
394
395 // Any file with a #import, should keep #import-ing.
396 for (auto &Inc : MainFileIncludes)
397 if (Inc.Directive == tok::pp_import)
398 return Symbol::IncludeDirective::Import;
399
400 // Any file declaring an ObjC decl should also be #import-ing.
401 // No need to look over the references, as the file doesn't have any #imports,
402 // it must be declaring interesting ObjC-like decls.
403 for (const Decl *D : TopLevelDecls)
404 if (isa<ObjCContainerDecl, ObjCIvarDecl, ObjCMethodDecl, ObjCPropertyDecl>(
405 D))
406 return Symbol::IncludeDirective::Import;
407
408 return Symbol::IncludeDirective::Include;
409}
410
411std::string printType(const QualType QT, const DeclContext &CurContext,
412 const llvm::StringRef Placeholder) {
413 std::string Result;
414 llvm::raw_string_ostream OS(Result);
415 PrintingPolicy PP(CurContext.getParentASTContext().getPrintingPolicy());
416 PP.SuppressTagKeyword = true;
417 PP.SuppressUnwrittenScope = true;
418
419 class PrintCB : public PrintingCallbacks {
420 public:
421 PrintCB(const DeclContext *CurContext) : CurContext(CurContext) {}
422 virtual ~PrintCB() {}
423 bool isScopeVisible(const DeclContext *DC) const override {
424 return DC->Encloses(CurContext);
425 }
426
427 private:
428 const DeclContext *CurContext;
429 };
430 PrintCB PCB(&CurContext);
431 PP.Callbacks = &PCB;
432
433 QT.print(OS, PP, Placeholder);
434 return OS.str();
435}
436
437bool hasReservedName(const Decl &D) {
438 if (const auto *ND = llvm::dyn_cast<NamedDecl>(&D))
439 if (const auto *II = ND->getIdentifier())
440 return isReservedName(II->getName());
441 return false;
442}
443
444bool hasReservedScope(const DeclContext &DC) {
445 for (const DeclContext *D = &DC; D; D = D->getParent()) {
446 if (D->isTransparentContext() || D->isInlineNamespace())
447 continue;
448 if (const auto *ND = llvm::dyn_cast<NamedDecl>(D))
449 if (hasReservedName(*ND))
450 return true;
451 }
452 return false;
453}
454
455QualType declaredType(const TypeDecl *D) {
456 if (const auto *CTSD = llvm::dyn_cast<ClassTemplateSpecializationDecl>(D))
457 if (const auto *TSI = CTSD->getTypeAsWritten())
458 return TSI->getType();
459 return D->getASTContext().getTypeDeclType(D);
460}
461
462namespace {
463/// Computes the deduced type at a given location by visiting the relevant
464/// nodes. We use this to display the actual type when hovering over an "auto"
465/// keyword or "decltype()" expression.
466/// FIXME: This could have been a lot simpler by visiting AutoTypeLocs but it
467/// seems that the AutoTypeLocs that can be visited along with their AutoType do
468/// not have the deduced type set. Instead, we have to go to the appropriate
469/// DeclaratorDecl/FunctionDecl and work our back to the AutoType that does have
470/// a deduced type set. The AST should be improved to simplify this scenario.
471class DeducedTypeVisitor : public RecursiveASTVisitor<DeducedTypeVisitor> {
472 SourceLocation SearchedLocation;
473
474public:
475 DeducedTypeVisitor(SourceLocation SearchedLocation)
476 : SearchedLocation(SearchedLocation) {}
477
478 // Handle auto initializers:
479 //- auto i = 1;
480 //- decltype(auto) i = 1;
481 //- auto& i = 1;
482 //- auto* i = &a;
483 bool VisitDeclaratorDecl(DeclaratorDecl *D) {
484 if (!D->getTypeSourceInfo() ||
485 D->getTypeSourceInfo()->getTypeLoc().getBeginLoc() != SearchedLocation)
486 return true;
487
488 if (auto *AT = D->getType()->getContainedAutoType()) {
489 DeducedType = AT->desugar();
490 }
491 return true;
492 }
493
494 // Handle auto return types:
495 //- auto foo() {}
496 //- auto& foo() {}
497 //- auto foo() -> int {}
498 //- auto foo() -> decltype(1+1) {}
499 //- operator auto() const { return 10; }
500 bool VisitFunctionDecl(FunctionDecl *D) {
501 if (!D->getTypeSourceInfo())
502 return true;
503 // Loc of auto in return type (c++14).
504 auto CurLoc = D->getReturnTypeSourceRange().getBegin();
505 // Loc of "auto" in operator auto()
506 if (CurLoc.isInvalid() && isa<CXXConversionDecl>(D))
507 CurLoc = D->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
508 // Loc of "auto" in function with trailing return type (c++11).
509 if (CurLoc.isInvalid())
510 CurLoc = D->getSourceRange().getBegin();
511 if (CurLoc != SearchedLocation)
512 return true;
513
514 const AutoType *AT = D->getReturnType()->getContainedAutoType();
515 if (AT && !AT->getDeducedType().isNull()) {
516 DeducedType = AT->getDeducedType();
517 } else if (auto *DT = dyn_cast<DecltypeType>(D->getReturnType())) {
518 // auto in a trailing return type just points to a DecltypeType and
519 // getContainedAutoType does not unwrap it.
520 if (!DT->getUnderlyingType().isNull())
521 DeducedType = DT->getUnderlyingType();
522 } else if (!D->getReturnType().isNull()) {
523 DeducedType = D->getReturnType();
524 }
525 return true;
526 }
527
528 // Handle non-auto decltype, e.g.:
529 // - auto foo() -> decltype(expr) {}
530 // - decltype(expr);
531 bool VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
532 if (TL.getBeginLoc() != SearchedLocation)
533 return true;
534
535 // A DecltypeType's underlying type can be another DecltypeType! E.g.
536 // int I = 0;
537 // decltype(I) J = I;
538 // decltype(J) K = J;
539 const DecltypeType *DT = dyn_cast<DecltypeType>(TL.getTypePtr());
540 while (DT && !DT->getUnderlyingType().isNull()) {
541 DeducedType = DT->getUnderlyingType();
542 DT = dyn_cast<DecltypeType>(DeducedType.getTypePtr());
543 }
544 return true;
545 }
546
547 // Handle functions/lambdas with `auto` typed parameters.
548 // We deduce the type if there's exactly one instantiation visible.
549 bool VisitParmVarDecl(ParmVarDecl *PVD) {
550 if (!PVD->getType()->isDependentType())
551 return true;
552 // 'auto' here does not name an AutoType, but an implicit template param.
553 TemplateTypeParmTypeLoc Auto =
554 getContainedAutoParamType(PVD->getTypeSourceInfo()->getTypeLoc());
555 if (Auto.isNull() || Auto.getNameLoc() != SearchedLocation)
556 return true;
557
558 // We expect the TTP to be attached to this function template.
559 // Find the template and the param index.
560 auto *Templated = llvm::dyn_cast<FunctionDecl>(PVD->getDeclContext());
561 if (!Templated)
562 return true;
563 auto *FTD = Templated->getDescribedFunctionTemplate();
564 if (!FTD)
565 return true;
566 int ParamIndex = paramIndex(*FTD, *Auto.getDecl());
567 if (ParamIndex < 0) {
568 assert(false && "auto TTP is not from enclosing function?")(static_cast <bool> (false && "auto TTP is not from enclosing function?"
) ? void (0) : __assert_fail ("false && \"auto TTP is not from enclosing function?\""
, "clang-tools-extra/clangd/AST.cpp", 568, __extension__ __PRETTY_FUNCTION__
));
569 return true;
570 }
571
572 // Now find the instantiation and the deduced template type arg.
573 auto *Instantiation =
574 llvm::dyn_cast_or_null<FunctionDecl>(getOnlyInstantiation(Templated));
575 if (!Instantiation)
576 return true;
577 const auto *Args = Instantiation->getTemplateSpecializationArgs();
578 if (Args->size() != FTD->getTemplateParameters()->size())
579 return true; // no weird variadic stuff
580 DeducedType = Args->get(ParamIndex).getAsType();
581 return true;
582 }
583
584 static int paramIndex(const TemplateDecl &TD, NamedDecl &Param) {
585 unsigned I = 0;
586 for (auto *ND : *TD.getTemplateParameters()) {
587 if (&Param == ND)
588 return I;
589 ++I;
590 }
591 return -1;
592 }
593
594 QualType DeducedType;
595};
596} // namespace
597
598std::optional<QualType> getDeducedType(ASTContext &ASTCtx, SourceLocation Loc) {
599 if (!Loc.isValid())
600 return {};
601 DeducedTypeVisitor V(Loc);
602 V.TraverseAST(ASTCtx);
603 if (V.DeducedType.isNull())
604 return std::nullopt;
605 return V.DeducedType;
606}
607
608TemplateTypeParmTypeLoc getContainedAutoParamType(TypeLoc TL) {
609 if (auto QTL = TL.getAs<QualifiedTypeLoc>())
610 return getContainedAutoParamType(QTL.getUnqualifiedLoc());
611 if (llvm::isa<PointerType, ReferenceType, ParenType>(TL.getTypePtr()))
612 return getContainedAutoParamType(TL.getNextTypeLoc());
613 if (auto FTL = TL.getAs<FunctionTypeLoc>())
614 return getContainedAutoParamType(FTL.getReturnLoc());
615 if (auto TTPTL = TL.getAs<TemplateTypeParmTypeLoc>()) {
616 if (TTPTL.getTypePtr()->getDecl()->isImplicit())
617 return TTPTL;
618 }
619 return {};
620}
621
622template <typename TemplateDeclTy>
623static NamedDecl *getOnlyInstantiationImpl(TemplateDeclTy *TD) {
624 NamedDecl *Only = nullptr;
625 for (auto *Spec : TD->specializations()) {
626 if (Spec->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
627 continue;
628 if (Only != nullptr)
629 return nullptr;
630 Only = Spec;
631 }
632 return Only;
633}
634
635NamedDecl *getOnlyInstantiation(NamedDecl *TemplatedDecl) {
636 if (TemplateDecl *TD = TemplatedDecl->getDescribedTemplate()) {
637 if (auto *CTD = llvm::dyn_cast<ClassTemplateDecl>(TD))
638 return getOnlyInstantiationImpl(CTD);
639 if (auto *FTD = llvm::dyn_cast<FunctionTemplateDecl>(TD))
640 return getOnlyInstantiationImpl(FTD);
641 if (auto *VTD = llvm::dyn_cast<VarTemplateDecl>(TD))
642 return getOnlyInstantiationImpl(VTD);
643 }
644 return nullptr;
645}
646
647std::vector<const Attr *> getAttributes(const DynTypedNode &N) {
648 std::vector<const Attr *> Result;
649 if (const auto *TL = N.get<TypeLoc>()) {
650 for (AttributedTypeLoc ATL = TL->getAs<AttributedTypeLoc>(); !ATL.isNull();
651 ATL = ATL.getModifiedLoc().getAs<AttributedTypeLoc>()) {
652 if (const Attr *A = ATL.getAttr())
653 Result.push_back(A);
654 assert(!ATL.getModifiedLoc().isNull())(static_cast <bool> (!ATL.getModifiedLoc().isNull()) ? void
(0) : __assert_fail ("!ATL.getModifiedLoc().isNull()", "clang-tools-extra/clangd/AST.cpp"
, 654, __extension__ __PRETTY_FUNCTION__));
655 }
656 }
657 if (const auto *S = N.get<AttributedStmt>()) {
658 for (; S != nullptr; S = dyn_cast<AttributedStmt>(S->getSubStmt()))
659 for (const Attr *A : S->getAttrs())
660 if (A)
661 Result.push_back(A);
662 }
663 if (const auto *D = N.get<Decl>()) {
664 for (const Attr *A : D->attrs())
665 if (A)
666 Result.push_back(A);
667 }
668 return Result;
669}
670
671std::string getQualification(ASTContext &Context,
672 const DeclContext *DestContext,
673 SourceLocation InsertionPoint,
674 const NamedDecl *ND) {
675 auto VisibleNamespaceDecls =
676 getUsingNamespaceDirectives(DestContext, InsertionPoint);
677 return getQualification(
678 Context, DestContext, ND->getDeclContext(),
679 [&](NestedNameSpecifier *NNS) {
680 if (NNS->getKind() != NestedNameSpecifier::Namespace)
681 return false;
682 const auto *CanonNSD = NNS->getAsNamespace()->getCanonicalDecl();
683 return llvm::any_of(VisibleNamespaceDecls,
684 [CanonNSD](const NamespaceDecl *NSD) {
685 return NSD->getCanonicalDecl() == CanonNSD;
686 });
687 });
688}
689
690std::string getQualification(ASTContext &Context,
691 const DeclContext *DestContext,
692 const NamedDecl *ND,
693 llvm::ArrayRef<std::string> VisibleNamespaces) {
694 for (llvm::StringRef NS : VisibleNamespaces) {
695 assert(NS.endswith("::"))(static_cast <bool> (NS.endswith("::")) ? void (0) : __assert_fail
("NS.endswith(\"::\")", "clang-tools-extra/clangd/AST.cpp", 695
, __extension__ __PRETTY_FUNCTION__));
696 (void)NS;
697 }
698 return getQualification(
699 Context, DestContext, ND->getDeclContext(),
700 [&](NestedNameSpecifier *NNS) {
701 return llvm::any_of(VisibleNamespaces, [&](llvm::StringRef Namespace) {
702 std::string NS;
703 llvm::raw_string_ostream OS(NS);
704 NNS->print(OS, Context.getPrintingPolicy());
705 return OS.str() == Namespace;
706 });
707 });
708}
709
710bool hasUnstableLinkage(const Decl *D) {
711 // Linkage of a ValueDecl depends on the type.
712 // If that's not deduced yet, deducing it may change the linkage.
713 auto *VD = llvm::dyn_cast_or_null<ValueDecl>(D);
714 return VD && !VD->getType().isNull() && VD->getType()->isUndeducedType();
715}
716
717bool isDeeplyNested(const Decl *D, unsigned MaxDepth) {
718 size_t ContextDepth = 0;
719 for (auto *Ctx = D->getDeclContext(); Ctx && !Ctx->isTranslationUnit();
720 Ctx = Ctx->getParent()) {
721 if (++ContextDepth == MaxDepth)
722 return true;
723 }
724 return false;
725}
726
727namespace {
728
729// returns true for `X` in `template <typename... X> void foo()`
730bool isTemplateTypeParameterPack(NamedDecl *D) {
731 if (const auto *TTPD = dyn_cast<TemplateTypeParmDecl>(D)) {
732 return TTPD->isParameterPack();
733 }
734 return false;
735}
736
737// Returns the template parameter pack type from an instantiated function
738// template, if it exists, nullptr otherwise.
739const TemplateTypeParmType *getFunctionPackType(const FunctionDecl *Callee) {
740 if (const auto *TemplateDecl = Callee->getPrimaryTemplate()) {
2
←
Assuming 'TemplateDecl' is non-null
→
3
←
Taking true branch
→
741 auto TemplateParams = TemplateDecl->getTemplateParameters()->asArray();
742 // find the template parameter pack from the back
743 const auto It = std::find_if(TemplateParams.rbegin(), TemplateParams.rend(),
744 isTemplateTypeParameterPack);
745 if (It != TemplateParams.rend()) {
4
←
Taking true branch
→
746 const auto *TTPD = dyn_cast<TemplateTypeParmDecl>(*It);
5
←
Assuming the object is not a 'CastReturnType'
→
6
←
'TTPD' initialized to a null pointer value
→
747 return TTPD->getTypeForDecl()->castAs<TemplateTypeParmType>();
7
←
Called C++ object pointer is null
748 }
749 }
750 return nullptr;
751}
752
753// Returns the template parameter pack type that this parameter was expanded
754// from (if in the Args... or Args&... or Args&&... form), if this is the case,
755// nullptr otherwise.
756const TemplateTypeParmType *getUnderylingPackType(const ParmVarDecl *Param) {
757 const auto *PlainType = Param->getType().getTypePtr();
758 if (auto *RT = dyn_cast<ReferenceType>(PlainType))
759 PlainType = RT->getPointeeTypeAsWritten().getTypePtr();
760 if (const auto *SubstType = dyn_cast<SubstTemplateTypeParmType>(PlainType)) {
761 const auto *ReplacedParameter = SubstType->getReplacedParameter();
762 if (ReplacedParameter->isParameterPack()) {
763 return ReplacedParameter->getTypeForDecl()
764 ->castAs<TemplateTypeParmType>();
765 }
766 }
767 return nullptr;
768}
769
770// This visitor walks over the body of an instantiated function template.
771// The template accepts a parameter pack and the visitor records whether
772// the pack parameters were forwarded to another call. For example, given:
773//
774// template <typename T, typename... Args>
775// auto make_unique(Args... args) {
776// return unique_ptr<T>(new T(args...));
777// }
778//
779// When called as `make_unique<std::string>(2, 'x')` this yields a function
780// `make_unique<std::string, int, char>` with two parameters.
781// The visitor records that those two parameters are forwarded to the
782// `constructor std::string(int, char);`.
783//
784// This information is recorded in the `ForwardingInfo` split into fully
785// resolved parameters (passed as argument to a parameter that is not an
786// expanded template type parameter pack) and forwarding parameters (passed to a
787// parameter that is an expanded template type parameter pack).
788class ForwardingCallVisitor
789 : public RecursiveASTVisitor<ForwardingCallVisitor> {
790public:
791 ForwardingCallVisitor(ArrayRef<const ParmVarDecl *> Parameters)
792 : Parameters{Parameters}, PackType{getUnderylingPackType(
793 Parameters.front())} {}
794
795 bool VisitCallExpr(CallExpr *E) {
796 auto *Callee = getCalleeDeclOrUniqueOverload(E);
797 if (Callee) {
798 handleCall(Callee, E->arguments());
799 }
800 return !Info.has_value();
801 }
802
803 bool VisitCXXConstructExpr(CXXConstructExpr *E) {
804 auto *Callee = E->getConstructor();
805 if (Callee) {
806 handleCall(Callee, E->arguments());
807 }
808 return !Info.has_value();
809 }
810
811 // The expanded parameter pack to be resolved
812 ArrayRef<const ParmVarDecl *> Parameters;
813 // The type of the parameter pack
814 const TemplateTypeParmType *PackType;
815
816 struct ForwardingInfo {
817 // If the parameters were resolved to another FunctionDecl, these are its
818 // first non-variadic parameters (i.e. the first entries of the parameter
819 // pack that are passed as arguments bound to a non-pack parameter.)
820 ArrayRef<const ParmVarDecl *> Head;
821 // If the parameters were resolved to another FunctionDecl, these are its
822 // variadic parameters (i.e. the entries of the parameter pack that are
823 // passed as arguments bound to a pack parameter.)
824 ArrayRef<const ParmVarDecl *> Pack;
825 // If the parameters were resolved to another FunctionDecl, these are its
826 // last non-variadic parameters (i.e. the last entries of the parameter pack
827 // that are passed as arguments bound to a non-pack parameter.)
828 ArrayRef<const ParmVarDecl *> Tail;
829 // If the parameters were resolved to another forwarding FunctionDecl, this
830 // is it.
831 std::optional<FunctionDecl *> PackTarget;
832 };
833
834 // The output of this visitor
835 std::optional<ForwardingInfo> Info;
836
837private:
838 // inspects the given callee with the given args to check whether it
839 // contains Parameters, and sets Info accordingly.
840 void handleCall(FunctionDecl *Callee, typename CallExpr::arg_range Args) {
841 // Skip functions with less parameters, they can't be the target.
842 if (Callee->parameters().size() < Parameters.size())
843 return;
844 if (llvm::any_of(Args,
845 [](const Expr *E) { return isa<PackExpansionExpr>(E); })) {
846 return;
847 }
848 auto PackLocation = findPack(Args);
849 if (!PackLocation)
850 return;
851 ArrayRef<ParmVarDecl *> MatchingParams =
852 Callee->parameters().slice(*PackLocation, Parameters.size());
853 // Check whether the function has a parameter pack as the last template
854 // parameter
855 if (const auto *TTPT = getFunctionPackType(Callee)) {
856 // In this case: Separate the parameters into head, pack and tail
857 auto IsExpandedPack = [&](const ParmVarDecl *P) {
858 return getUnderylingPackType(P) == TTPT;
859 };
860 ForwardingInfo FI;
861 FI.Head = MatchingParams.take_until(IsExpandedPack);
862 FI.Pack =
863 MatchingParams.drop_front(FI.Head.size()).take_while(IsExpandedPack);
864 FI.Tail = MatchingParams.drop_front(FI.Head.size() + FI.Pack.size());
865 FI.PackTarget = Callee;
866 Info = FI;
867 return;
868 }
869 // Default case: assume all parameters were fully resolved
870 ForwardingInfo FI;
871 FI.Head = MatchingParams;
872 Info = FI;
873 }
874
875 // Returns the beginning of the expanded pack represented by Parameters
876 // in the given arguments, if it is there.
877 std::optional<size_t> findPack(typename CallExpr::arg_range Args) {
878 // find the argument directly referring to the first parameter
879 assert(Parameters.size() <= static_cast<size_t>(llvm::size(Args)))(static_cast <bool> (Parameters.size() <= static_cast
<size_t>(llvm::size(Args))) ? void (0) : __assert_fail (
"Parameters.size() <= static_cast<size_t>(llvm::size(Args))"
, "clang-tools-extra/clangd/AST.cpp", 879, __extension__ __PRETTY_FUNCTION__
));
880 for (auto Begin = Args.begin(), End = Args.end() - Parameters.size() + 1;
881 Begin != End; ++Begin) {
882 if (const auto *RefArg = unwrapForward(*Begin)) {
883 if (Parameters.front() != RefArg->getDecl())
884 continue;
885 // Check that this expands all the way until the last parameter.
886 // It's enough to look at the last parameter, because it isn't possible
887 // to expand without expanding all of them.
888 auto ParamEnd = Begin + Parameters.size() - 1;
889 RefArg = unwrapForward(*ParamEnd);
890 if (!RefArg || Parameters.back() != RefArg->getDecl())
891 continue;
892 return std::distance(Args.begin(), Begin);
893 }
894 }
895 return std::nullopt;
896 }
897
898 static FunctionDecl *getCalleeDeclOrUniqueOverload(CallExpr *E) {
899 Decl *CalleeDecl = E->getCalleeDecl();
900 auto *Callee = dyn_cast_or_null<FunctionDecl>(CalleeDecl);
901 if (!Callee) {
902 if (auto *Lookup = dyn_cast<UnresolvedLookupExpr>(E->getCallee())) {
903 Callee = resolveOverload(Lookup, E);
904 }
905 }
906 // Ignore the callee if the number of arguments is wrong (deal with va_args)
907 if (Callee && Callee->getNumParams() == E->getNumArgs())
908 return Callee;
909 return nullptr;
910 }
911
912 static FunctionDecl *resolveOverload(UnresolvedLookupExpr *Lookup,
913 CallExpr *E) {
914 FunctionDecl *MatchingDecl = nullptr;
915 if (!Lookup->requiresADL()) {
916 // Check whether there is a single overload with this number of
917 // parameters
918 for (auto *Candidate : Lookup->decls()) {
919 if (auto *FuncCandidate = dyn_cast_or_null<FunctionDecl>(Candidate)) {
920 if (FuncCandidate->getNumParams() == E->getNumArgs()) {
921 if (MatchingDecl) {
922 // there are multiple candidates - abort
923 return nullptr;
924 }
925 MatchingDecl = FuncCandidate;
926 }
927 }
928 }
929 }
930 return MatchingDecl;
931 }
932
933 // Tries to get to the underlying argument by unwrapping implicit nodes and
934 // std::forward.
935 static const DeclRefExpr *unwrapForward(const Expr *E) {
936 E = E->IgnoreImplicitAsWritten();
937 // There might be an implicit copy/move constructor call on top of the
938 // forwarded arg.
939 // FIXME: Maybe mark implicit calls in the AST to properly filter here.
940 if (const auto *Const = dyn_cast<CXXConstructExpr>(E))
941 if (Const->getConstructor()->isCopyOrMoveConstructor())
942 E = Const->getArg(0)->IgnoreImplicitAsWritten();
943 if (const auto *Call = dyn_cast<CallExpr>(E)) {
944 const auto Callee = Call->getBuiltinCallee();
945 if (Callee == Builtin::BIforward) {
946 return dyn_cast<DeclRefExpr>(
947 Call->getArg(0)->IgnoreImplicitAsWritten());
948 }
949 }
950 return dyn_cast<DeclRefExpr>(E);
951 }
952};
953
954} // namespace
955
956SmallVector<const ParmVarDecl *>
957resolveForwardingParameters(const FunctionDecl *D, unsigned MaxDepth) {
958 auto Parameters = D->parameters();
959 // If the function has a template parameter pack
960 if (const auto *TTPT = getFunctionPackType(D)) {
1
Calling 'getFunctionPackType'
→
961 // Split the parameters into head, pack and tail
962 auto IsExpandedPack = [TTPT](const ParmVarDecl *P) {
963 return getUnderylingPackType(P) == TTPT;
964 };
965 ArrayRef<const ParmVarDecl *> Head = Parameters.take_until(IsExpandedPack);
966 ArrayRef<const ParmVarDecl *> Pack =
967 Parameters.drop_front(Head.size()).take_while(IsExpandedPack);
968 ArrayRef<const ParmVarDecl *> Tail =
969 Parameters.drop_front(Head.size() + Pack.size());
970 SmallVector<const ParmVarDecl *> Result(Parameters.size());
971 // Fill in non-pack parameters
972 auto HeadIt = std::copy(Head.begin(), Head.end(), Result.begin());
973 auto TailIt = std::copy(Tail.rbegin(), Tail.rend(), Result.rbegin());
974 // Recurse on pack parameters
975 size_t Depth = 0;
976 const FunctionDecl *CurrentFunction = D;
977 llvm::SmallSet<const FunctionTemplateDecl *, 4> SeenTemplates;
978 if (const auto *Template = D->getPrimaryTemplate()) {
979 SeenTemplates.insert(Template);
980 }
981 while (!Pack.empty() && CurrentFunction && Depth < MaxDepth) {
982 // Find call expressions involving the pack
983 ForwardingCallVisitor V{Pack};
984 V.TraverseStmt(CurrentFunction->getBody());
985 if (!V.Info) {
986 break;
987 }
988 // If we found something: Fill in non-pack parameters
989 auto Info = *V.Info;
990 HeadIt = std::copy(Info.Head.begin(), Info.Head.end(), HeadIt);
991 TailIt = std::copy(Info.Tail.rbegin(), Info.Tail.rend(), TailIt);
992 // Prepare next recursion level
993 Pack = Info.Pack;
994 CurrentFunction = Info.PackTarget.value_or(nullptr);
995 Depth++;
996 // If we are recursing into a previously encountered function: Abort
997 if (CurrentFunction) {
998 if (const auto *Template = CurrentFunction->getPrimaryTemplate()) {
999 bool NewFunction = SeenTemplates.insert(Template).second;
1000 if (!NewFunction) {
1001 return {Parameters.begin(), Parameters.end()};
1002 }
1003 }
1004 }
1005 }
1006 // Fill in the remaining unresolved pack parameters
1007 HeadIt = std::copy(Pack.begin(), Pack.end(), HeadIt);
1008 assert(TailIt.base() == HeadIt)(static_cast <bool> (TailIt.base() == HeadIt) ? void (0
) : __assert_fail ("TailIt.base() == HeadIt", "clang-tools-extra/clangd/AST.cpp"
, 1008, __extension__ __PRETTY_FUNCTION__));
1009 return Result;
1010 }
1011 return {Parameters.begin(), Parameters.end()};
1012}
1013
1014bool isExpandedFromParameterPack(const ParmVarDecl *D) {
1015 return getUnderylingPackType(D) != nullptr;
1016}
1017
1018} // namespace clangd
1019} // namespace clang