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//===--- Sema.cpp - AST Builder and Semantic Analysis Implementation ------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file implements the actions class which performs semantic analysis and
// builds an AST out of a parse stream.
#include "UsedDeclVisitor.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTDiagnostic.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclFriend.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/PrettyDeclStackTrace.h"
#include "clang/AST/StmtCXX.h"
#include "clang/Basic/DarwinSDKInfo.h"
#include "clang/Basic/DiagnosticOptions.h"
#include "clang/Basic/PartialDiagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/Stack.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/HeaderSearchOptions.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Sema/CXXFieldCollector.h"
#include "clang/Sema/DelayedDiagnostic.h"
#include "clang/Sema/ExternalSemaSource.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/MultiplexExternalSemaSource.h"
#include "clang/Sema/ObjCMethodList.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/SemaConsumer.h"
#include "clang/Sema/SemaInternal.h"
#include "clang/Sema/TemplateDeduction.h"
#include "clang/Sema/TemplateInstCallback.h"
#include "clang/Sema/TypoCorrection.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Support/TimeProfiler.h"
using namespace clang;
using namespace sema;
SourceLocation Sema::getLocForEndOfToken(SourceLocation Loc, unsigned Offset) {
return Lexer::getLocForEndOfToken(Loc, Offset, SourceMgr, LangOpts);
ModuleLoader &Sema::getModuleLoader() const { return PP.getModuleLoader(); }
DarwinSDKInfo *
Sema::getDarwinSDKInfoForAvailabilityChecking(SourceLocation Loc,
StringRef Platform) {
if (CachedDarwinSDKInfo)
return CachedDarwinSDKInfo->get();
auto SDKInfo = parseDarwinSDKInfo(
if (SDKInfo && *SDKInfo) {
CachedDarwinSDKInfo = std::make_unique<DarwinSDKInfo>(std::move(**SDKInfo));
return CachedDarwinSDKInfo->get();
if (!SDKInfo)
Diag(Loc, diag::warn_missing_sdksettings_for_availability_checking)
<< Platform;
CachedDarwinSDKInfo = std::unique_ptr<DarwinSDKInfo>();
return nullptr;
IdentifierInfo *
Sema::InventAbbreviatedTemplateParameterTypeName(IdentifierInfo *ParamName,
unsigned int Index) {
std::string InventedName;
llvm::raw_string_ostream OS(InventedName);
if (!ParamName)
OS << "auto:" << Index + 1;
OS << ParamName->getName() << ":auto";
return &Context.Idents.get(OS.str());
PrintingPolicy Sema::getPrintingPolicy(const ASTContext &Context,
const Preprocessor &PP) {
PrintingPolicy Policy = Context.getPrintingPolicy();
// In diagnostics, we print _Bool as bool if the latter is defined as the
// former.
Policy.Bool = Context.getLangOpts().Bool;
if (!Policy.Bool) {
if (const MacroInfo *BoolMacro = PP.getMacroInfo(Context.getBoolName())) {
Policy.Bool = BoolMacro->isObjectLike() &&
BoolMacro->getNumTokens() == 1 &&
return Policy;
void Sema::ActOnTranslationUnitScope(Scope *S) {
TUScope = S;
PushDeclContext(S, Context.getTranslationUnitDecl());
namespace clang {
namespace sema {
class SemaPPCallbacks : public PPCallbacks {
Sema *S = nullptr;
llvm::SmallVector<SourceLocation, 8> IncludeStack;
void set(Sema &S) { this->S = &S; }
void reset() { S = nullptr; }
virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
SrcMgr::CharacteristicKind FileType,
FileID PrevFID) override {
if (!S)
switch (Reason) {
case EnterFile: {
SourceManager &SM = S->getSourceManager();
SourceLocation IncludeLoc = SM.getIncludeLoc(SM.getFileID(Loc));
if (IncludeLoc.isValid()) {
if (llvm::timeTraceProfilerEnabled()) {
const FileEntry *FE = SM.getFileEntryForID(SM.getFileID(Loc));
"Source", FE != nullptr ? FE->getName() : StringRef("<unknown>"));
case ExitFile:
if (!IncludeStack.empty()) {
if (llvm::timeTraceProfilerEnabled())
} // end namespace sema
} // end namespace clang
const unsigned Sema::MaxAlignmentExponent;
const uint64_t Sema::MaximumAlignment;
Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
TranslationUnitKind TUKind, CodeCompleteConsumer *CodeCompleter)
: ExternalSource(nullptr), isMultiplexExternalSource(false),
CurFPFeatures(pp.getLangOpts()), LangOpts(pp.getLangOpts()), PP(pp),
Context(ctxt), Consumer(consumer), Diags(PP.getDiagnostics()),
SourceMgr(PP.getSourceManager()), CollectStats(false),
CodeCompleter(CodeCompleter), CurContext(nullptr),
OriginalLexicalContext(nullptr), MSStructPragmaOn(false),
DataSegStack(nullptr), BSSSegStack(nullptr), ConstSegStack(nullptr),
CodeSegStack(nullptr), FpPragmaStack(FPOptionsOverride()),
CurInitSeg(nullptr), VisContext(nullptr),
IsBuildingRecoveryCallExpr(false), Cleanup{}, LateTemplateParser(nullptr),
LateTemplateParserCleanup(nullptr), OpaqueParser(nullptr), IdResolver(pp),
StdExperimentalNamespaceCache(nullptr), StdInitializerList(nullptr),
StdCoroutineTraitsCache(nullptr), CXXTypeInfoDecl(nullptr),
MSVCGuidDecl(nullptr), NSNumberDecl(nullptr), NSValueDecl(nullptr),
NSStringDecl(nullptr), StringWithUTF8StringMethod(nullptr),
ValueWithBytesObjCTypeMethod(nullptr), NSArrayDecl(nullptr),
ArrayWithObjectsMethod(nullptr), NSDictionaryDecl(nullptr),
DictionaryWithObjectsMethod(nullptr), GlobalNewDeleteDeclared(false),
TUKind(TUKind), NumSFINAEErrors(0),
static_cast<unsigned>(ComparisonCategoryType::Last) + 1),
SatisfactionCache(Context), AccessCheckingSFINAE(false),
InNonInstantiationSFINAEContext(false), NonInstantiationEntries(0),
ArgumentPackSubstitutionIndex(-1), CurrentInstantiationScope(nullptr),
DisableTypoCorrection(false), TyposCorrected(0), AnalysisWarnings(*this),
ThreadSafetyDeclCache(nullptr), VarDataSharingAttributesStack(nullptr),
CurScope(nullptr), Ident_super(nullptr), Ident___float128(nullptr) {
assert(pp.TUKind == TUKind);
TUScope = nullptr;
isConstantEvaluatedOverride = false;
LoadedExternalKnownNamespaces = false;
for (unsigned I = 0; I != NSAPI::NumNSNumberLiteralMethods; ++I)
NSNumberLiteralMethods[I] = nullptr;
if (getLangOpts().ObjC)
NSAPIObj.reset(new NSAPI(Context));
if (getLangOpts().CPlusPlus)
FieldCollector.reset(new CXXFieldCollector());
// Tell diagnostics how to render things from the AST library.
Diags.SetArgToStringFn(&FormatASTNodeDiagnosticArgument, &Context);
ExpressionEvaluationContext::PotentiallyEvaluated, 0, CleanupInfo{},
nullptr, ExpressionEvaluationContextRecord::EK_Other);
// Initialization of data sharing attributes stack for OpenMP
std::unique_ptr<sema::SemaPPCallbacks> Callbacks =
SemaPPCallbackHandler = Callbacks.get();
// Anchor Sema's type info to this TU.
void Sema::anchor() {}
void Sema::addImplicitTypedef(StringRef Name, QualType T) {
DeclarationName DN = &Context.Idents.get(Name);
if (IdResolver.begin(DN) == IdResolver.end())
PushOnScopeChains(Context.buildImplicitTypedef(T, Name), TUScope);
void Sema::Initialize() {
if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer))
// Tell the external Sema source about this Sema object.
if (ExternalSemaSource *ExternalSema
= dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource()))
// This needs to happen after ExternalSemaSource::InitializeSema(this) or we
// will not be able to merge any duplicate __va_list_tag decls correctly.
VAListTagName = PP.getIdentifierInfo("__va_list_tag");
if (!TUScope)
// Initialize predefined 128-bit integer types, if needed.
if (Context.getTargetInfo().hasInt128Type() ||
(Context.getAuxTargetInfo() &&
Context.getAuxTargetInfo()->hasInt128Type())) {
// If either of the 128-bit integer types are unavailable to name lookup,
// define them now.
DeclarationName Int128 = &Context.Idents.get("__int128_t");
if (IdResolver.begin(Int128) == IdResolver.end())
PushOnScopeChains(Context.getInt128Decl(), TUScope);
DeclarationName UInt128 = &Context.Idents.get("__uint128_t");
if (IdResolver.begin(UInt128) == IdResolver.end())
PushOnScopeChains(Context.getUInt128Decl(), TUScope);
// Initialize predefined Objective-C types:
if (getLangOpts().ObjC) {
// If 'SEL' does not yet refer to any declarations, make it refer to the
// predefined 'SEL'.
DeclarationName SEL = &Context.Idents.get("SEL");
if (IdResolver.begin(SEL) == IdResolver.end())
PushOnScopeChains(Context.getObjCSelDecl(), TUScope);
// If 'id' does not yet refer to any declarations, make it refer to the
// predefined 'id'.
DeclarationName Id = &Context.Idents.get("id");
if (IdResolver.begin(Id) == IdResolver.end())
PushOnScopeChains(Context.getObjCIdDecl(), TUScope);
// Create the built-in typedef for 'Class'.
DeclarationName Class = &Context.Idents.get("Class");
if (IdResolver.begin(Class) == IdResolver.end())
PushOnScopeChains(Context.getObjCClassDecl(), TUScope);
// Create the built-in forward declaratino for 'Protocol'.
DeclarationName Protocol = &Context.Idents.get("Protocol");
if (IdResolver.begin(Protocol) == IdResolver.end())
PushOnScopeChains(Context.getObjCProtocolDecl(), TUScope);
// Create the internal type for the *StringMakeConstantString builtins.
DeclarationName ConstantString = &Context.Idents.get("__NSConstantString");
if (IdResolver.begin(ConstantString) == IdResolver.end())
PushOnScopeChains(Context.getCFConstantStringDecl(), TUScope);
// Initialize Microsoft "predefined C++ types".
if (getLangOpts().MSVCCompat) {
if (getLangOpts().CPlusPlus &&
IdResolver.begin(&Context.Idents.get("type_info")) == IdResolver.end())
PushOnScopeChains(Context.buildImplicitRecord("type_info", TTK_Class),
addImplicitTypedef("size_t", Context.getSizeType());
// Initialize predefined OpenCL types and supported extensions and (optional)
// core features.
if (getLangOpts().OpenCL) {
Context.getTargetInfo().getSupportedOpenCLOpts(), getLangOpts());
addImplicitTypedef("sampler_t", Context.OCLSamplerTy);
addImplicitTypedef("event_t", Context.OCLEventTy);
if (getLangOpts().getOpenCLCompatibleVersion() >= 200) {
addImplicitTypedef("clk_event_t", Context.OCLClkEventTy);
addImplicitTypedef("queue_t", Context.OCLQueueTy);
if (getLangOpts().OpenCLPipes)
addImplicitTypedef("reserve_id_t", Context.OCLReserveIDTy);
addImplicitTypedef("atomic_int", Context.getAtomicType(Context.IntTy));
// OpenCLC v2.0, s6.13.11.6 requires that atomic_flag is implemented as
// 32-bit integer and OpenCLC v2.0, s6.1.1 int is always 32-bit wide.
addImplicitTypedef("atomic_flag", Context.getAtomicType(Context.IntTy));
// OpenCL v2.0 s6.13.11.6:
// - The atomic_long and atomic_ulong types are supported if the
// cl_khr_int64_base_atomics and cl_khr_int64_extended_atomics
// extensions are supported.
// - The atomic_double type is only supported if double precision
// is supported and the cl_khr_int64_base_atomics and
// cl_khr_int64_extended_atomics extensions are supported.
// - If the device address space is 64-bits, the data types
// atomic_intptr_t, atomic_uintptr_t, atomic_size_t and
// atomic_ptrdiff_t are supported if the cl_khr_int64_base_atomics and
// cl_khr_int64_extended_atomics extensions are supported.
auto AddPointerSizeDependentTypes = [&]() {
auto AtomicSizeT = Context.getAtomicType(Context.getSizeType());
auto AtomicIntPtrT = Context.getAtomicType(Context.getIntPtrType());
auto AtomicUIntPtrT = Context.getAtomicType(Context.getUIntPtrType());
auto AtomicPtrDiffT =
addImplicitTypedef("atomic_size_t", AtomicSizeT);
addImplicitTypedef("atomic_intptr_t", AtomicIntPtrT);
addImplicitTypedef("atomic_uintptr_t", AtomicUIntPtrT);
addImplicitTypedef("atomic_ptrdiff_t", AtomicPtrDiffT);
if (Context.getTypeSize(Context.getSizeType()) == 32) {
if (getOpenCLOptions().isSupported("cl_khr_fp16", getLangOpts())) {
auto AtomicHalfT = Context.getAtomicType(Context.HalfTy);
addImplicitTypedef("atomic_half", AtomicHalfT);
std::vector<QualType> Atomic64BitTypes;
if (getOpenCLOptions().isSupported("cl_khr_int64_base_atomics",
getLangOpts()) &&
getLangOpts())) {
if (getOpenCLOptions().isSupported("cl_khr_fp64", getLangOpts())) {
auto AtomicDoubleT = Context.getAtomicType(Context.DoubleTy);
addImplicitTypedef("atomic_double", AtomicDoubleT);
auto AtomicLongT = Context.getAtomicType(Context.LongTy);
auto AtomicULongT = Context.getAtomicType(Context.UnsignedLongTy);
addImplicitTypedef("atomic_long", AtomicLongT);
addImplicitTypedef("atomic_ulong", AtomicULongT);
if (Context.getTypeSize(Context.getSizeType()) == 64) {
#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
if (getOpenCLOptions().isSupported(#Ext, getLangOpts())) { \
addImplicitTypedef(#ExtType, Context.Id##Ty); \
#include "clang/Basic/OpenCLExtensionTypes.def"
if (Context.getTargetInfo().hasAArch64SVETypes()) {
#define SVE_TYPE(Name, Id, SingletonId) \
addImplicitTypedef(Name, Context.SingletonId);
#include "clang/Basic/AArch64SVEACLETypes.def"
if (Context.getTargetInfo().getTriple().isPPC64()) {
#define PPC_VECTOR_MMA_TYPE(Name, Id, Size) \
addImplicitTypedef(#Name, Context.Id##Ty);
#include "clang/Basic/PPCTypes.def"
#define PPC_VECTOR_VSX_TYPE(Name, Id, Size) \
addImplicitTypedef(#Name, Context.Id##Ty);
#include "clang/Basic/PPCTypes.def"
if (Context.getTargetInfo().hasRISCVVTypes()) {
#define RVV_TYPE(Name, Id, SingletonId) \
addImplicitTypedef(Name, Context.SingletonId);
#include "clang/Basic/RISCVVTypes.def"
if (Context.getTargetInfo().hasBuiltinMSVaList()) {
DeclarationName MSVaList = &Context.Idents.get("__builtin_ms_va_list");
if (IdResolver.begin(MSVaList) == IdResolver.end())
PushOnScopeChains(Context.getBuiltinMSVaListDecl(), TUScope);
DeclarationName BuiltinVaList = &Context.Idents.get("__builtin_va_list");
if (IdResolver.begin(BuiltinVaList) == IdResolver.end())
PushOnScopeChains(Context.getBuiltinVaListDecl(), TUScope);
Sema::~Sema() {
assert(InstantiatingSpecializations.empty() &&
"failed to clean up an InstantiatingTemplate?");
if (VisContext) FreeVisContext();
// Kill all the active scopes.
for (sema::FunctionScopeInfo *FSI : FunctionScopes)
delete FSI;
// Tell the SemaConsumer to forget about us; we're going out of scope.
if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer))
// Detach from the external Sema source.
if (ExternalSemaSource *ExternalSema
= dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource()))
// If Sema's ExternalSource is the multiplexer - we own it.
if (isMultiplexExternalSource)
delete ExternalSource;
// Delete cached satisfactions.
std::vector<ConstraintSatisfaction *> Satisfactions;
for (auto &Node : SatisfactionCache)
for (auto *Node : Satisfactions)
delete Node;
// Destroys data sharing attributes stack for OpenMP
// Detach from the PP callback handler which outlives Sema since it's owned
// by the preprocessor.
void Sema::warnStackExhausted(SourceLocation Loc) {
// Only warn about this once.
if (!WarnedStackExhausted) {
Diag(Loc, diag::warn_stack_exhausted);
WarnedStackExhausted = true;
void Sema::runWithSufficientStackSpace(SourceLocation Loc,
llvm::function_ref<void()> Fn) {
clang::runWithSufficientStackSpace([&] { warnStackExhausted(Loc); }, Fn);
/// makeUnavailableInSystemHeader - There is an error in the current
/// context. If we're still in a system header, and we can plausibly
/// make the relevant declaration unavailable instead of erroring, do
/// so and return true.
bool Sema::makeUnavailableInSystemHeader(SourceLocation loc,
UnavailableAttr::ImplicitReason reason) {
// If we're not in a function, it's an error.
FunctionDecl *fn = dyn_cast<FunctionDecl>(CurContext);
if (!fn) return false;
// If we're in template instantiation, it's an error.
if (inTemplateInstantiation())
return false;
// If that function's not in a system header, it's an error.
if (!Context.getSourceManager().isInSystemHeader(loc))
return false;
// If the function is already unavailable, it's not an error.
if (fn->hasAttr<UnavailableAttr>()) return true;
fn->addAttr(UnavailableAttr::CreateImplicit(Context, "", reason, loc));
return true;
ASTMutationListener *Sema::getASTMutationListener() const {
return getASTConsumer().GetASTMutationListener();
///Registers an external source. If an external source already exists,
/// creates a multiplex external source and appends to it.
///\param[in] E - A non-null external sema source.
void Sema::addExternalSource(ExternalSemaSource *E) {
assert(E && "Cannot use with NULL ptr");
if (!ExternalSource) {
ExternalSource = E;
if (isMultiplexExternalSource)
else {
ExternalSource = new MultiplexExternalSemaSource(*ExternalSource, *E);
isMultiplexExternalSource = true;
/// Print out statistics about the semantic analysis.
void Sema::PrintStats() const {
llvm::errs() << "\n*** Semantic Analysis Stats:\n";
llvm::errs() << NumSFINAEErrors << " SFINAE diagnostics trapped.\n";
void Sema::diagnoseNullableToNonnullConversion(QualType DstType,
QualType SrcType,
SourceLocation Loc) {
Optional<NullabilityKind> ExprNullability = SrcType->getNullability(Context);
if (!ExprNullability || (*ExprNullability != NullabilityKind::Nullable &&
*ExprNullability != NullabilityKind::NullableResult))
Optional<NullabilityKind> TypeNullability = DstType->getNullability(Context);
if (!TypeNullability || *TypeNullability != NullabilityKind::NonNull)
Diag(Loc, diag::warn_nullability_lost) << SrcType << DstType;
void Sema::diagnoseZeroToNullptrConversion(CastKind Kind, const Expr* E) {
if (Diags.isIgnored(diag::warn_zero_as_null_pointer_constant,
// nullptr only exists from C++11 on, so don't warn on its absence earlier.
if (!getLangOpts().CPlusPlus11)
if (Kind != CK_NullToPointer && Kind != CK_NullToMemberPointer)
if (E->IgnoreParenImpCasts()->getType()->isNullPtrType())
// Don't diagnose the conversion from a 0 literal to a null pointer argument
// in a synthesized call to operator<=>.
if (!CodeSynthesisContexts.empty() &&
CodeSynthesisContexts.back().Kind ==
// If it is a macro from system header, and if the macro name is not "NULL",
// do not warn.
SourceLocation MaybeMacroLoc = E->getBeginLoc();
if (Diags.getSuppressSystemWarnings() &&
SourceMgr.isInSystemMacro(MaybeMacroLoc) &&
!findMacroSpelling(MaybeMacroLoc, "NULL"))
Diag(E->getBeginLoc(), diag::warn_zero_as_null_pointer_constant)
<< FixItHint::CreateReplacement(E->getSourceRange(), "nullptr");
/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast.
/// If there is already an implicit cast, merge into the existing one.
/// The result is of the given category.
ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
CastKind Kind, ExprValueKind VK,
const CXXCastPath *BasePath,
CheckedConversionKind CCK) {
#ifndef NDEBUG
if (VK == VK_PRValue && !E->isPRValue()) {
switch (Kind) {
("can't implicitly cast glvalue to prvalue with this cast "
"kind: " +
case CK_Dependent:
case CK_LValueToRValue:
case CK_ArrayToPointerDecay:
case CK_FunctionToPointerDecay:
case CK_ToVoid:
case CK_NonAtomicToAtomic:
assert((VK == VK_PRValue || Kind == CK_Dependent || !E->isPRValue()) &&
"can't cast prvalue to glvalue");
diagnoseNullableToNonnullConversion(Ty, E->getType(), E->getBeginLoc());
diagnoseZeroToNullptrConversion(Kind, E);
QualType ExprTy = Context.getCanonicalType(E->getType());
QualType TypeTy = Context.getCanonicalType(Ty);
if (ExprTy == TypeTy)
return E;
if (Kind == CK_ArrayToPointerDecay) {
// C++1z [conv.array]: The temporary materialization conversion is applied.
// We also use this to fuel C++ DR1213, which applies to C++11 onwards.
if (getLangOpts().CPlusPlus && E->isPRValue()) {
// The temporary is an lvalue in C++98 and an xvalue otherwise.
ExprResult Materialized = CreateMaterializeTemporaryExpr(
E->getType(), E, !getLangOpts().CPlusPlus11);
if (Materialized.isInvalid())
return ExprError();
E = Materialized.get();
// C17 6.7.1p6 footnote 124: The implementation can treat any register
// declaration simply as an auto declaration. However, whether or not
// addressable storage is actually used, the address of any part of an
// object declared with storage-class specifier register cannot be
// computed, either explicitly(by use of the unary & operator as discussed
// in or implicitly(by converting an array name to a pointer as
// discussed in, the only operator that can be applied to an
// array declared with storage-class specifier register is sizeof.
if (VK == VK_PRValue && !getLangOpts().CPlusPlus && !E->isPRValue()) {
if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) {
if (const auto *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
if (VD->getStorageClass() == SC_Register) {
Diag(E->getExprLoc(), diag::err_typecheck_address_of)
<< /*register variable*/ 3 << E->getSourceRange();
return ExprError();
if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(E)) {
if (ImpCast->getCastKind() == Kind && (!BasePath || BasePath->empty())) {
return E;
return ImplicitCastExpr::Create(Context, Ty, Kind, E, BasePath, VK,
/// ScalarTypeToBooleanCastKind - Returns the cast kind corresponding
/// to the conversion from scalar type ScalarTy to the Boolean type.
CastKind Sema::ScalarTypeToBooleanCastKind(QualType ScalarTy) {
switch (ScalarTy->getScalarTypeKind()) {
case Type::STK_Bool: return CK_NoOp;
case Type::STK_CPointer: return CK_PointerToBoolean;
case Type::STK_BlockPointer: return CK_PointerToBoolean;
case Type::STK_ObjCObjectPointer: return CK_PointerToBoolean;
case Type::STK_MemberPointer: return CK_MemberPointerToBoolean;
case Type::STK_Integral: return CK_IntegralToBoolean;
case Type::STK_Floating: return CK_FloatingToBoolean;
case Type::STK_IntegralComplex: return CK_IntegralComplexToBoolean;
case Type::STK_FloatingComplex: return CK_FloatingComplexToBoolean;
case Type::STK_FixedPoint: return CK_FixedPointToBoolean;
llvm_unreachable("unknown scalar type kind");
/// Used to prune the decls of Sema's UnusedFileScopedDecls vector.
static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) {
if (D->getMostRecentDecl()->isUsed())
return true;
if (D->isExternallyVisible())
return true;
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
// If this is a function template and none of its specializations is used,
// we should warn.
if (FunctionTemplateDecl *Template = FD->getDescribedFunctionTemplate())
for (const auto *Spec : Template->specializations())
if (ShouldRemoveFromUnused(SemaRef, Spec))
return true;
// UnusedFileScopedDecls stores the first declaration.
// The declaration may have become definition so check again.
const FunctionDecl *DeclToCheck;
if (FD->hasBody(DeclToCheck))
return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
// Later redecls may add new information resulting in not having to warn,
// so check again.
DeclToCheck = FD->getMostRecentDecl();
if (DeclToCheck != FD)
return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
// If a variable usable in constant expressions is referenced,
// don't warn if it isn't used: if the value of a variable is required
// for the computation of a constant expression, it doesn't make sense to
// warn even if the variable isn't odr-used. (isReferenced doesn't
// precisely reflect that, but it's a decent approximation.)
if (VD->isReferenced() &&
return true;
if (VarTemplateDecl *Template = VD->getDescribedVarTemplate())
// If this is a variable template and none of its specializations is used,
// we should warn.
for (const auto *Spec : Template->specializations())
if (ShouldRemoveFromUnused(SemaRef, Spec))
return true;
// UnusedFileScopedDecls stores the first declaration.
// The declaration may have become definition so check again.
const VarDecl *DeclToCheck = VD->getDefinition();
if (DeclToCheck)
return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
// Later redecls may add new information resulting in not having to warn,
// so check again.
DeclToCheck = VD->getMostRecentDecl();
if (DeclToCheck != VD)
return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
return false;
static bool isFunctionOrVarDeclExternC(NamedDecl *ND) {
if (auto *FD = dyn_cast<FunctionDecl>(ND))
return FD->isExternC();
return cast<VarDecl>(ND)->isExternC();
/// Determine whether ND is an external-linkage function or variable whose
/// type has no linkage.
bool Sema::isExternalWithNoLinkageType(ValueDecl *VD) {
// Note: it's not quite enough to check whether VD has UniqueExternalLinkage,
// because we also want to catch the case where its type has VisibleNoLinkage,
// which does not affect the linkage of VD.
return getLangOpts().CPlusPlus && VD->hasExternalFormalLinkage() &&
!isExternalFormalLinkage(VD->getType()->getLinkage()) &&
/// Obtains a sorted list of functions and variables that are undefined but
/// ODR-used.
void Sema::getUndefinedButUsed(
SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> > &Undefined) {
for (const auto &UndefinedUse : UndefinedButUsed) {
NamedDecl *ND = UndefinedUse.first;
// Ignore attributes that have become invalid.
if (ND->isInvalidDecl()) continue;
// __attribute__((weakref)) is basically a definition.
if (ND->hasAttr<WeakRefAttr>()) continue;
if (isa<CXXDeductionGuideDecl>(ND))
if (ND->hasAttr<DLLImportAttr>() || ND->hasAttr<DLLExportAttr>()) {
// An exported function will always be emitted when defined, so even if
// the function is inline, it doesn't have to be emitted in this TU. An
// imported function implies that it has been exported somewhere else.
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
if (FD->isDefined())
if (FD->isExternallyVisible() &&
!isExternalWithNoLinkageType(FD) &&
!FD->getMostRecentDecl()->isInlined() &&
if (FD->getBuiltinID())
} else {
auto *VD = cast<VarDecl>(ND);
if (VD->hasDefinition() != VarDecl::DeclarationOnly)
if (VD->isExternallyVisible() &&
!isExternalWithNoLinkageType(VD) &&
!VD->getMostRecentDecl()->isInline() &&
// Skip VarDecls that lack formal definitions but which we know are in
// fact defined somewhere.
if (VD->isKnownToBeDefined())
Undefined.push_back(std::make_pair(ND, UndefinedUse.second));
/// checkUndefinedButUsed - Check for undefined objects with internal linkage
/// or that are inline.
static void checkUndefinedButUsed(Sema &S) {
if (S.UndefinedButUsed.empty()) return;
// Collect all the still-undefined entities with internal linkage.
SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
if (Undefined.empty()) return;
for (auto Undef : Undefined) {
ValueDecl *VD = cast<ValueDecl>(Undef.first);
SourceLocation UseLoc = Undef.second;
if (S.isExternalWithNoLinkageType(VD)) {
// C++ []p8:
// A type without linkage shall not be used as the type of a variable
// or function with external linkage unless
// -- the entity has C language linkage
// -- the entity is not odr-used or is defined in the same TU
// As an extension, accept this in cases where the type is externally
// visible, since the function or variable actually can be defined in
// another translation unit in that case.
S.Diag(VD->getLocation(), isExternallyVisible(VD->getType()->getLinkage())
? diag::ext_undefined_internal_type
: diag::err_undefined_internal_type)
<< isa<VarDecl>(VD) << VD;
} else if (!VD->isExternallyVisible()) {
// FIXME: We can promote this to an error. The function or variable can't
// be defined anywhere else, so the program must necessarily violate the
// one definition rule.
bool IsImplicitBase = false;
if (const auto *BaseD = dyn_cast<FunctionDecl>(VD)) {
auto *DVAttr = BaseD->getAttr<OMPDeclareVariantAttr>();
if (DVAttr && !DVAttr->getTraitInfo().isExtensionActive(
implementation_extension_disable_implicit_base)) {
const auto *Func = cast<FunctionDecl>(
IsImplicitBase = BaseD->isImplicit() &&
if (!S.getLangOpts().OpenMP || !IsImplicitBase)
S.Diag(VD->getLocation(), diag::warn_undefined_internal)
<< isa<VarDecl>(VD) << VD;
} else if (auto *FD = dyn_cast<FunctionDecl>(VD)) {
assert(FD->getMostRecentDecl()->isInlined() &&
"used object requires definition but isn't inline or internal?");
// FIXME: This is ill-formed; we should reject.
S.Diag(VD->getLocation(), diag::warn_undefined_inline) << VD;
} else {
assert(cast<VarDecl>(VD)->getMostRecentDecl()->isInline() &&
"used var requires definition but isn't inline or internal?");
S.Diag(VD->getLocation(), diag::err_undefined_inline_var) << VD;
if (UseLoc.isValid())
S.Diag(UseLoc, diag::note_used_here);
void Sema::LoadExternalWeakUndeclaredIdentifiers() {
if (!ExternalSource)
SmallVector<std::pair<IdentifierInfo *, WeakInfo>, 4> WeakIDs;
for (auto &WeakID : WeakIDs)
typedef llvm::DenseMap<const CXXRecordDecl*, bool> RecordCompleteMap;
/// Returns true, if all methods and nested classes of the given
/// CXXRecordDecl are defined in this translation unit.
/// Should only be called from ActOnEndOfTranslationUnit so that all
/// definitions are actually read.
static bool MethodsAndNestedClassesComplete(const CXXRecordDecl *RD,
RecordCompleteMap &MNCComplete) {
RecordCompleteMap::iterator Cache = MNCComplete.find(RD);
if (Cache != MNCComplete.end())
return Cache->second;
if (!RD->isCompleteDefinition())
return false;
bool Complete = true;
for (DeclContext::decl_iterator I = RD->decls_begin(),
E = RD->decls_end();
I != E && Complete; ++I) {
if (const CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(*I))
Complete = M->isDefined() || M->isDefaulted() ||
(M->isPure() && !isa<CXXDestructorDecl>(M));
else if (const FunctionTemplateDecl *F = dyn_cast<FunctionTemplateDecl>(*I))
// If the template function is marked as late template parsed at this
// point, it has not been instantiated and therefore we have not
// performed semantic analysis on it yet, so we cannot know if the type
// can be considered complete.
Complete = !F->getTemplatedDecl()->isLateTemplateParsed() &&
else if (const CXXRecordDecl *R = dyn_cast<CXXRecordDecl>(*I)) {
if (R->isInjectedClassName())
if (R->hasDefinition())
Complete = MethodsAndNestedClassesComplete(R->getDefinition(),
Complete = false;
MNCComplete[RD] = Complete;
return Complete;
/// Returns true, if the given CXXRecordDecl is fully defined in this
/// translation unit, i.e. all methods are defined or pure virtual and all
/// friends, friend functions and nested classes are fully defined in this
/// translation unit.
/// Should only be called from ActOnEndOfTranslationUnit so that all
/// definitions are actually read.
static bool IsRecordFullyDefined(const CXXRecordDecl *RD,
RecordCompleteMap &RecordsComplete,
RecordCompleteMap &MNCComplete) {
RecordCompleteMap::iterator Cache = RecordsComplete.find(RD);
if (Cache != RecordsComplete.end())
return Cache->second;
bool Complete = MethodsAndNestedClassesComplete(RD, MNCComplete);
for (CXXRecordDecl::friend_iterator I = RD->friend_begin(),
E = RD->friend_end();
I != E && Complete; ++I) {
// Check if friend classes and methods are complete.
if (TypeSourceInfo *TSI = (*I)->getFriendType()) {
// Friend classes are available as the TypeSourceInfo of the FriendDecl.
if (CXXRecordDecl *FriendD = TSI->getType()->getAsCXXRecordDecl())
Complete = MethodsAndNestedClassesComplete(FriendD, MNCComplete);
Complete = false;
} else {
// Friend functions are available through the NamedDecl of FriendDecl.
if (const FunctionDecl *FD =
Complete = FD->isDefined();
// This is a template friend, give up.
Complete = false;
RecordsComplete[RD] = Complete;
return Complete;
void Sema::emitAndClearUnusedLocalTypedefWarnings() {
if (ExternalSource)
for (const TypedefNameDecl *TD : UnusedLocalTypedefNameCandidates) {
if (TD->isReferenced())
Diag(TD->getLocation(), diag::warn_unused_local_typedef)
<< isa<TypeAliasDecl>(TD) << TD->getDeclName();
/// This is called before the very first declaration in the translation unit
/// is parsed. Note that the ASTContext may have already injected some
/// declarations.
void Sema::ActOnStartOfTranslationUnit() {
if (getLangOpts().ModulesTS &&
(getLangOpts().getCompilingModule() == LangOptions::CMK_ModuleInterface ||
getLangOpts().getCompilingModule() == LangOptions::CMK_None)) {
// We start in an implied global module fragment.
SourceLocation StartOfTU =
ModuleScopes.back().ImplicitGlobalModuleFragment = true;
void Sema::ActOnEndOfTranslationUnitFragment(TUFragmentKind Kind) {
// No explicit actions are required at the end of the global module fragment.
if (Kind == TUFragmentKind::Global)
// Transfer late parsed template instantiations over to the pending template
// instantiation list. During normal compilation, the late template parser
// will be installed and instantiating these templates will succeed.
// If we are building a TU prefix for serialization, it is also safe to
// transfer these over, even though they are not parsed. The end of the TU
// should be outside of any eager template instantiation scope, so when this
// AST is deserialized, these templates will not be parsed until the end of
// the combined TU.
// If DefinedUsedVTables ends up marking any virtual member functions it
// might lead to more pending template instantiations, which we then need
// to instantiate.
// C++: Perform implicit template instantiations.
// FIXME: When we perform these implicit instantiations, we do not
// carefully keep track of the point of instantiation (C++ [temp.point]).
// This means that name lookup that occurs within the template
// instantiation will always happen at the end of the translation unit,
// so it will find some names that are not required to be found. This is
// valid, but we could do better by diagnosing if an instantiation uses a
// name that was not visible at its first point of instantiation.
if (ExternalSource) {
// Load pending instantiations from the external source.
SmallVector<PendingImplicitInstantiation, 4> Pending;
for (auto PII : Pending)
if (auto Func = dyn_cast<FunctionDecl>(PII.first))
Pending.begin(), Pending.end());
llvm::TimeTraceScope TimeScope("PerformPendingInstantiations");
assert(LateParsedInstantiations.empty() &&
"end of TU template instantiation should not create more "
"late-parsed templates");
// Report diagnostics for uncorrected delayed typos. Ideally all of them
// should have been corrected by that time, but it is very hard to cover all
// cases in practice.
for (const auto &Typo : DelayedTypos) {
// We pass an empty TypoCorrection to indicate no correction was performed.
/// ActOnEndOfTranslationUnit - This is called at the very end of the
/// translation unit when EOF is reached and all but the top-level scope is
/// popped.
void Sema::ActOnEndOfTranslationUnit() {
assert(DelayedDiagnostics.getCurrentPool() == nullptr
&& "reached end of translation unit with a pool attached?");
// If code completion is enabled, don't perform any end-of-translation-unit
// work.
if (PP.isCodeCompletionEnabled())
// Complete translation units and modules define vtables and perform implicit
// instantiations. PCH files do not.
if (TUKind != TU_Prefix) {
!ModuleScopes.empty() && ModuleScopes.back().Module->Kind ==
? TUFragmentKind::Private
: TUFragmentKind::Normal);
if (LateTemplateParserCleanup)
} else {
// If we are building a TU prefix for serialization, it is safe to transfer
// these over, even though they are not parsed. The end of the TU should be
// outside of any eager template instantiation scope, so when this AST is
// deserialized, these templates will not be parsed until the end of the
// combined TU.
if (LangOpts.PCHInstantiateTemplates) {
llvm::TimeTraceScope TimeScope("PerformPendingInstantiations");
// All delayed member exception specs should be checked or we end up accepting
// incompatible declarations.
// All dllexport classes should have been processed already.
// Remove file scoped decls that turned out to be used.
std::remove_if(UnusedFileScopedDecls.begin(nullptr, true),
[this](const DeclaratorDecl *DD) {
return ShouldRemoveFromUnused(this, DD);
if (TUKind == TU_Prefix) {
// Translation unit prefixes don't need any of the checking below.
if (!PP.isIncrementalProcessingEnabled())
TUScope = nullptr;
// Check for #pragma weak identifiers that were never declared
for (auto WeakID : WeakUndeclaredIdentifiers) {
if (WeakID.second.getUsed())
Decl *PrevDecl = LookupSingleName(TUScope, WeakID.first, SourceLocation(),
if (PrevDecl != nullptr &&
!(isa<FunctionDecl>(PrevDecl) || isa<VarDecl>(PrevDecl)))
Diag(WeakID.second.getLocation(), diag::warn_attribute_wrong_decl_type)
<< "'weak'" << ExpectedVariableOrFunction;
Diag(WeakID.second.getLocation(), diag::warn_weak_identifier_undeclared)
<< WeakID.first;
if (LangOpts.CPlusPlus11 &&
!Diags.isIgnored(diag::warn_delegating_ctor_cycle, SourceLocation()))
if (!Diags.hasErrorOccurred()) {
if (ExternalSource)
// A global-module-fragment is only permitted within a module unit.
bool DiagnosedMissingModuleDeclaration = false;
if (!ModuleScopes.empty() &&
ModuleScopes.back().Module->Kind == Module::GlobalModuleFragment &&
!ModuleScopes.back().ImplicitGlobalModuleFragment) {
DiagnosedMissingModuleDeclaration = true;
if (TUKind == TU_Module) {
// If we are building a module interface unit, we need to have seen the
// module declaration by now.
if (getLangOpts().getCompilingModule() ==
LangOptions::CMK_ModuleInterface &&
(ModuleScopes.empty() ||
!ModuleScopes.back().Module->isModulePurview()) &&
!DiagnosedMissingModuleDeclaration) {
// FIXME: Make a better guess as to where to put the module declaration.
// If we are building a module, resolve all of the exported declarations
// now.
if (Module *CurrentModule = PP.getCurrentModule()) {
ModuleMap &ModMap = PP.getHeaderSearchInfo().getModuleMap();
SmallVector<Module *, 2> Stack;
while (!Stack.empty()) {
Module *Mod = Stack.pop_back_val();
// Resolve the exported declarations and conflicts.
// FIXME: Actually complain, once we figure out how to teach the
// diagnostic client to deal with complaints in the module map at this
// point.
ModMap.resolveExports(Mod, /*Complain=*/false);
ModMap.resolveUses(Mod, /*Complain=*/false);
ModMap.resolveConflicts(Mod, /*Complain=*/false);
// Queue the submodules, so their exports will also be resolved.
Stack.append(Mod->submodule_begin(), Mod->submodule_end());
// Warnings emitted in ActOnEndOfTranslationUnit() should be emitted for
// modules when they are built, not every time they are used.
// C99 6.9.2p2:
// A declaration of an identifier for an object that has file
// scope without an initializer, and without a storage-class
// specifier or with the storage-class specifier static,
// constitutes a tentative definition. If a translation unit
// contains one or more tentative definitions for an identifier,
// and the translation unit contains no external definition for
// that identifier, then the behavior is exactly as if the
// translation unit contains a file scope declaration of that
// identifier, with the composite type as of the end of the
// translation unit, with an initializer equal to 0.
llvm::SmallSet<VarDecl *, 32> Seen;
for (TentativeDefinitionsType::iterator
T = TentativeDefinitions.begin(ExternalSource),
TEnd = TentativeDefinitions.end();
T != TEnd; ++T) {
VarDecl *VD = (*T)->getActingDefinition();
// If the tentative definition was completed, getActingDefinition() returns
// null. If we've already seen this variable before, insert()'s second
// return value is false.
if (!VD || VD->isInvalidDecl() || !Seen.insert(VD).second)
if (const IncompleteArrayType *ArrayT
= Context.getAsIncompleteArrayType(VD->getType())) {
// Set the length of the array to 1 (C99 6.9.2p5).
Diag(VD->getLocation(), diag::warn_tentative_incomplete_array);
llvm::APInt One(Context.getTypeSize(Context.getSizeType()), true);
QualType T = Context.getConstantArrayType(ArrayT->getElementType(), One,
nullptr, ArrayType::Normal, 0);
} else if (RequireCompleteType(VD->getLocation(), VD->getType(),
// No initialization is performed for a tentative definition.
// Notify the consumer that we've completed a tentative definition.
if (!VD->isInvalidDecl())
for (auto D : ExternalDeclarations) {
if (!D || D->isInvalidDecl() || D->getPreviousDecl() || !D->isUsed())
// If there were errors, disable 'unused' warnings since they will mostly be
// noise. Don't warn for a use from a module: either we should warn on all
// file-scope declarations in modules or not at all, but whether the
// declaration is used is immaterial.
if (!Diags.hasErrorOccurred() && TUKind != TU_Module) {
// Output warning for unused file scoped decls.
for (UnusedFileScopedDeclsType::iterator
I = UnusedFileScopedDecls.begin(ExternalSource),
E = UnusedFileScopedDecls.end(); I != E; ++I) {
if (ShouldRemoveFromUnused(this, *I))
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
const FunctionDecl *DiagD;
if (!FD->hasBody(DiagD))
DiagD = FD;
if (DiagD->isDeleted())
continue; // Deleted functions are supposed to be unused.
if (DiagD->isReferenced()) {
if (isa<CXXMethodDecl>(DiagD))
Diag(DiagD->getLocation(), diag::warn_unneeded_member_function)
<< DiagD;
else {
if (FD->getStorageClass() == SC_Static &&
!FD->isInlineSpecified() &&
<< DiagD;
Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl)
<< /*function*/ 0 << DiagD;
} else {
if (FD->getDescribedFunctionTemplate())
Diag(DiagD->getLocation(), diag::warn_unused_template)
<< /*function*/ 0 << DiagD;
Diag(DiagD->getLocation(), isa<CXXMethodDecl>(DiagD)
? diag::warn_unused_member_function
: diag::warn_unused_function)
<< DiagD;
} else {
const VarDecl *DiagD = cast<VarDecl>(*I)->getDefinition();
if (!DiagD)
DiagD = cast<VarDecl>(*I);
if (DiagD->isReferenced()) {
Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl)
<< /*variable*/ 1 << DiagD;
} else if (DiagD->getType().isConstQualified()) {
const SourceManager &SM = SourceMgr;
if (SM.getMainFileID() != SM.getFileID(DiagD->getLocation()) ||
Diag(DiagD->getLocation(), diag::warn_unused_const_variable)
<< DiagD;
} else {
if (DiagD->getDescribedVarTemplate())
Diag(DiagD->getLocation(), diag::warn_unused_template)
<< /*variable*/ 1 << DiagD;
Diag(DiagD->getLocation(), diag::warn_unused_variable) << DiagD;
if (!Diags.isIgnored(diag::warn_unused_private_field, SourceLocation())) {
// FIXME: Load additional unused private field candidates from the external
// source.
RecordCompleteMap RecordsComplete;
RecordCompleteMap MNCComplete;
for (NamedDeclSetType::iterator I = UnusedPrivateFields.begin(),
E = UnusedPrivateFields.end(); I != E; ++I) {
const NamedDecl *D = *I;
const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
if (RD && !RD->isUnion() &&
IsRecordFullyDefined(RD, RecordsComplete, MNCComplete)) {
Diag(D->getLocation(), diag::warn_unused_private_field)
<< D->getDeclName();
if (!Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation())) {
if (ExternalSource)
for (const auto &DeletedFieldInfo : DeleteExprs) {
for (const auto &DeleteExprLoc : DeletedFieldInfo.second) {
AnalyzeDeleteExprMismatch(DeletedFieldInfo.first, DeleteExprLoc.first,
// Check we've noticed that we're no longer parsing the initializer for every
// variable. If we miss cases, then at best we have a performance issue and
// at worst a rejects-valid bug.
assert(ParsingInitForAutoVars.empty() &&
"Didn't unmark var as having its initializer parsed");
if (!PP.isIncrementalProcessingEnabled())
TUScope = nullptr;
// Helper functions.
DeclContext *Sema::getFunctionLevelDeclContext() {
DeclContext *DC = CurContext;
while (true) {
if (isa<BlockDecl>(DC) || isa<EnumDecl>(DC) || isa<CapturedDecl>(DC) ||
isa<RequiresExprBodyDecl>(DC)) {
DC = DC->getParent();
} else if (isa<CXXMethodDecl>(DC) &&
cast<CXXMethodDecl>(DC)->getOverloadedOperator() == OO_Call &&
cast<CXXRecordDecl>(DC->getParent())->isLambda()) {
DC = DC->getParent()->getParent();
else break;
return DC;
/// getCurFunctionDecl - If inside of a function body, this returns a pointer
/// to the function decl for the function being parsed. If we're currently
/// in a 'block', this returns the containing context.
FunctionDecl *Sema::getCurFunctionDecl() {
DeclContext *DC = getFunctionLevelDeclContext();
return dyn_cast<FunctionDecl>(DC);
ObjCMethodDecl *Sema::getCurMethodDecl() {
DeclContext *DC = getFunctionLevelDeclContext();
while (isa<RecordDecl>(DC))
DC = DC->getParent();
return dyn_cast<ObjCMethodDecl>(DC);
NamedDecl *Sema::getCurFunctionOrMethodDecl() {
DeclContext *DC = getFunctionLevelDeclContext();
if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC))
return cast<NamedDecl>(DC);
return nullptr;
LangAS Sema::getDefaultCXXMethodAddrSpace() const {
if (getLangOpts().OpenCL)
return getASTContext().getDefaultOpenCLPointeeAddrSpace();
return LangAS::Default;
void Sema::EmitCurrentDiagnostic(unsigned DiagID) {
// FIXME: It doesn't make sense to me that DiagID is an incoming argument here
// and yet we also use the current diag ID on the DiagnosticsEngine. This has
// been made more painfully obvious by the refactor that introduced this
// function, but it is possible that the incoming argument can be
// eliminated. If it truly cannot be (for example, there is some reentrancy
// issue I am not seeing yet), then there should at least be a clarifying
// comment somewhere.
if (Optional<TemplateDeductionInfo*> Info = isSFINAEContext()) {
switch (DiagnosticIDs::getDiagnosticSFINAEResponse(
Diags.getCurrentDiagID())) {
case DiagnosticIDs::SFINAE_Report:
// We'll report the diagnostic below.
case DiagnosticIDs::SFINAE_SubstitutionFailure:
// Count this failure so that we know that template argument deduction
// has failed.
// Make a copy of this suppressed diagnostic and store it with the
// template-deduction information.
if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
Diagnostic DiagInfo(&Diags);
PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
case DiagnosticIDs::SFINAE_AccessControl: {
// Per C++ Core Issue 1170, access control is part of SFINAE.
// Additionally, the AccessCheckingSFINAE flag can be used to temporarily
// make access control a part of SFINAE for the purposes of checking
// type traits.
if (!AccessCheckingSFINAE && !getLangOpts().CPlusPlus11)
SourceLocation Loc = Diags.getCurrentDiagLoc();
// Suppress this diagnostic.
// Make a copy of this suppressed diagnostic and store it with the
// template-deduction information.
if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
Diagnostic DiagInfo(&Diags);
PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
// Now the diagnostic state is clear, produce a C++98 compatibility
// warning.
Diag(Loc, diag::warn_cxx98_compat_sfinae_access_control);
// The last diagnostic which Sema produced was ignored. Suppress any
// notes attached to it.
case DiagnosticIDs::SFINAE_Suppress:
// Make a copy of this suppressed diagnostic and store it with the
// template-deduction information;
if (*Info) {
Diagnostic DiagInfo(&Diags);
PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
// Suppress this diagnostic.
// Copy the diagnostic printing policy over the ASTContext printing policy.
// TODO: Stop doing that. See:
// Emit the diagnostic.
if (!Diags.EmitCurrentDiagnostic())
// If this is not a note, and we're in a template instantiation
// that is different from the last template instantiation where
// we emitted an error, print a template instantiation
// backtrace.
if (!DiagnosticIDs::isBuiltinNote(DiagID))
Sema::Diag(SourceLocation Loc, const PartialDiagnostic &PD, bool DeferHint) {
return Diag(Loc, PD.getDiagID(), DeferHint) << PD;
bool Sema::hasUncompilableErrorOccurred() const {
if (getDiagnostics().hasUncompilableErrorOccurred())
return true;
auto *FD = dyn_cast<FunctionDecl>(CurContext);
if (!FD)
return false;
auto Loc = DeviceDeferredDiags.find(FD);
if (Loc == DeviceDeferredDiags.end())
return false;
for (auto PDAt : Loc->second) {
if (DiagnosticIDs::isDefaultMappingAsError(PDAt.second.getDiagID()))
return true;
return false;
// Print notes showing how we can reach FD starting from an a priori
// known-callable function.
static void emitCallStackNotes(Sema &S, FunctionDecl *FD) {
auto FnIt = S.DeviceKnownEmittedFns.find(FD);
while (FnIt != S.DeviceKnownEmittedFns.end()) {
// Respect error limit.
if (S.Diags.hasFatalErrorOccurred())
DiagnosticBuilder Builder(
S.Diags.Report(FnIt->second.Loc, diag::note_called_by));
Builder << FnIt->second.FD;
FnIt = S.DeviceKnownEmittedFns.find(FnIt->second.FD);
namespace {
/// Helper class that emits deferred diagnostic messages if an entity directly
/// or indirectly using the function that causes the deferred diagnostic
/// messages is known to be emitted.
/// During parsing of AST, certain diagnostic messages are recorded as deferred
/// diagnostics since it is unknown whether the functions containing such
/// diagnostics will be emitted. A list of potentially emitted functions and
/// variables that may potentially trigger emission of functions are also
/// recorded. DeferredDiagnosticsEmitter recursively visits used functions
/// by each function to emit deferred diagnostics.
/// During the visit, certain OpenMP directives or initializer of variables
/// with certain OpenMP attributes will cause subsequent visiting of any
/// functions enter a state which is called OpenMP device context in this
/// implementation. The state is exited when the directive or initializer is
/// exited. This state can change the emission states of subsequent uses
/// of functions.
/// Conceptually the functions or variables to be visited form a use graph
/// where the parent node uses the child node. At any point of the visit,
/// the tree nodes traversed from the tree root to the current node form a use
/// stack. The emission state of the current node depends on two factors:
/// 1. the emission state of the root node
/// 2. whether the current node is in OpenMP device context
/// If the function is decided to be emitted, its contained deferred diagnostics
/// are emitted, together with the information about the use stack.
class DeferredDiagnosticsEmitter
: public UsedDeclVisitor<DeferredDiagnosticsEmitter> {
typedef UsedDeclVisitor<DeferredDiagnosticsEmitter> Inherited;
// Whether the function is already in the current use-path.
llvm::SmallPtrSet<CanonicalDeclPtr<Decl>, 4> InUsePath;
// The current use-path.
llvm::SmallVector<CanonicalDeclPtr<FunctionDecl>, 4> UsePath;
// Whether the visiting of the function has been done. Done[0] is for the
// case not in OpenMP device context. Done[1] is for the case in OpenMP
// device context. We need two sets because diagnostics emission may be
// different depending on whether it is in OpenMP device context.
llvm::SmallPtrSet<CanonicalDeclPtr<Decl>, 4> DoneMap[2];
// Emission state of the root node of the current use graph.
bool ShouldEmitRootNode;
// Current OpenMP device context level. It is initialized to 0 and each
// entering of device context increases it by 1 and each exit decreases
// it by 1. Non-zero value indicates it is currently in device context.
unsigned InOMPDeviceContext;
DeferredDiagnosticsEmitter(Sema &S)
: Inherited(S), ShouldEmitRootNode(false), InOMPDeviceContext(0) {}
bool shouldVisitDiscardedStmt() const { return false; }
void VisitOMPTargetDirective(OMPTargetDirective *Node) {
void visitUsedDecl(SourceLocation Loc, Decl *D) {
if (isa<VarDecl>(D))
if (auto *FD = dyn_cast<FunctionDecl>(D))
checkFunc(Loc, FD);
Inherited::visitUsedDecl(Loc, D);
void checkVar(VarDecl *VD) {
assert(VD->isFileVarDecl() &&
"Should only check file-scope variables");
if (auto *Init = VD->getInit()) {
auto DevTy = OMPDeclareTargetDeclAttr::getDeviceType(VD);
bool IsDev = DevTy && (*DevTy == OMPDeclareTargetDeclAttr::DT_NoHost ||
*DevTy == OMPDeclareTargetDeclAttr::DT_Any);
if (IsDev)
if (IsDev)
void checkFunc(SourceLocation Loc, FunctionDecl *FD) {
auto &Done = DoneMap[InOMPDeviceContext > 0 ? 1 : 0];
FunctionDecl *Caller = UsePath.empty() ? nullptr : UsePath.back();
if ((!ShouldEmitRootNode && !S.getLangOpts().OpenMP && !Caller) ||
S.shouldIgnoreInHostDeviceCheck(FD) || InUsePath.count(FD))
// Finalize analysis of OpenMP-specific constructs.
if (Caller && S.LangOpts.OpenMP && UsePath.size() == 1 &&
(ShouldEmitRootNode || InOMPDeviceContext))
S.finalizeOpenMPDelayedAnalysis(Caller, FD, Loc);
if (Caller)
S.DeviceKnownEmittedFns[FD] = {Caller, Loc};
// Always emit deferred diagnostics for the direct users. This does not
// lead to explosion of diagnostics since each user is visited at most
// twice.
if (ShouldEmitRootNode || InOMPDeviceContext)
emitDeferredDiags(FD, Caller);
// Do not revisit a function if the function body has been completely
// visited before.
if (!Done.insert(FD).second)
if (auto *S = FD->getBody()) {
void checkRecordedDecl(Decl *D) {
if (auto *FD = dyn_cast<FunctionDecl>(D)) {
ShouldEmitRootNode = S.getEmissionStatus(FD, /*Final=*/true) ==
checkFunc(SourceLocation(), FD);
} else
// Emit any deferred diagnostics for FD
void emitDeferredDiags(FunctionDecl *FD, bool ShowCallStack) {
auto It = S.DeviceDeferredDiags.find(FD);
if (It == S.DeviceDeferredDiags.end())
bool HasWarningOrError = false;
bool FirstDiag = true;
for (PartialDiagnosticAt &PDAt : It->second) {
// Respect error limit.
if (S.Diags.hasFatalErrorOccurred())
const SourceLocation &Loc = PDAt.first;
const PartialDiagnostic &PD = PDAt.second;
HasWarningOrError |=
S.getDiagnostics().getDiagnosticLevel(PD.getDiagID(), Loc) >=
DiagnosticBuilder Builder(S.Diags.Report(Loc, PD.getDiagID()));
// Emit the note on the first diagnostic in case too many diagnostics
// cause the note not emitted.
if (FirstDiag && HasWarningOrError && ShowCallStack) {
emitCallStackNotes(S, FD);
FirstDiag = false;
} // namespace
void Sema::emitDeferredDiags() {
if (ExternalSource)
if ((DeviceDeferredDiags.empty() && !LangOpts.OpenMP) ||
DeferredDiagnosticsEmitter DDE(*this);
for (auto D : DeclsToCheckForDeferredDiags)
// In CUDA, there are some constructs which may appear in semantically-valid
// code, but trigger errors if we ever generate code for the function in which
// they appear. Essentially every construct you're not allowed to use on the
// device falls into this category, because you are allowed to use these
// constructs in a __host__ __device__ function, but only if that function is
// never codegen'ed on the device.
// To handle semantic checking for these constructs, we keep track of the set of
// functions we know will be emitted, either because we could tell a priori that
// they would be emitted, or because they were transitively called by a
// known-emitted function.
// We also keep a partial call graph of which not-known-emitted functions call
// which other not-known-emitted functions.
// When we see something which is illegal if the current function is emitted
// (usually by way of CUDADiagIfDeviceCode, CUDADiagIfHostCode, or
// CheckCUDACall), we first check if the current function is known-emitted. If
// so, we immediately output the diagnostic.
// Otherwise, we "defer" the diagnostic. It sits in Sema::DeviceDeferredDiags
// until we discover that the function is known-emitted, at which point we take
// it out of this map and emit the diagnostic.
Sema::SemaDiagnosticBuilder::SemaDiagnosticBuilder(Kind K, SourceLocation Loc,
unsigned DiagID,
FunctionDecl *Fn, Sema &S)
: S(S), Loc(Loc), DiagID(DiagID), Fn(Fn),
ShowCallStack(K == K_ImmediateWithCallStack || K == K_Deferred) {
switch (K) {
case K_Nop:
case K_Immediate:
case K_ImmediateWithCallStack:
ImmediateDiagBuilder(S.Diags.Report(Loc, DiagID), S, DiagID));
case K_Deferred:
assert(Fn && "Must have a function to attach the deferred diag to.");
auto &Diags = S.DeviceDeferredDiags[Fn];
Diags.emplace_back(Loc, S.PDiag(DiagID));
Sema::SemaDiagnosticBuilder::SemaDiagnosticBuilder(SemaDiagnosticBuilder &&D)
: S(D.S), Loc(D.Loc), DiagID(D.DiagID), Fn(D.Fn),
ShowCallStack(D.ShowCallStack), ImmediateDiag(D.ImmediateDiag),
PartialDiagId(D.PartialDiagId) {
// Clean the previous diagnostics.
D.ShowCallStack = false;
Sema::SemaDiagnosticBuilder::~SemaDiagnosticBuilder() {
if (ImmediateDiag) {
// Emit our diagnostic and, if it was a warning or error, output a callstack
// if Fn isn't a priori known-emitted.
bool IsWarningOrError = S.getDiagnostics().getDiagnosticLevel(
DiagID, Loc) >= DiagnosticsEngine::Warning;
ImmediateDiag.reset(); // Emit the immediate diag.
if (IsWarningOrError && ShowCallStack)
emitCallStackNotes(S, Fn);
} else {
assert((!PartialDiagId || ShowCallStack) &&
"Must always show call stack for deferred diags.");
Sema::targetDiag(SourceLocation Loc, unsigned DiagID, FunctionDecl *FD) {
FD = FD ? FD : getCurFunctionDecl();
if (LangOpts.OpenMP)
return LangOpts.OpenMPIsDevice ? diagIfOpenMPDeviceCode(Loc, DiagID, FD)
: diagIfOpenMPHostCode(Loc, DiagID, FD);
if (getLangOpts().CUDA)
return getLangOpts().CUDAIsDevice ? CUDADiagIfDeviceCode(Loc, DiagID)
: CUDADiagIfHostCode(Loc, DiagID);
if (getLangOpts().SYCLIsDevice)
return SYCLDiagIfDeviceCode(Loc, DiagID);
return SemaDiagnosticBuilder(SemaDiagnosticBuilder::K_Immediate, Loc, DiagID,
FD, *this);
Sema::SemaDiagnosticBuilder Sema::Diag(SourceLocation Loc, unsigned DiagID,
bool DeferHint) {
bool IsError = Diags.getDiagnosticIDs()->isDefaultMappingAsError(DiagID);
bool ShouldDefer = getLangOpts().CUDA && LangOpts.GPUDeferDiag &&
DiagnosticIDs::isDeferrable(DiagID) &&
(DeferHint || DeferDiags || !IsError);
auto SetIsLastErrorImmediate = [&](bool Flag) {
if (IsError)
IsLastErrorImmediate = Flag;
if (!ShouldDefer) {
return SemaDiagnosticBuilder(SemaDiagnosticBuilder::K_Immediate, Loc,
DiagID, getCurFunctionDecl(), *this);
SemaDiagnosticBuilder DB = getLangOpts().CUDAIsDevice
? CUDADiagIfDeviceCode(Loc, DiagID)
: CUDADiagIfHostCode(Loc, DiagID);
return DB;
void Sema::checkTypeSupport(QualType Ty, SourceLocation Loc, ValueDecl *D) {
if (isUnevaluatedContext() || Ty.isNull())
Decl *C = cast<Decl>(getCurLexicalContext());
// Memcpy operations for structs containing a member with unsupported type
// are ok, though.
if (const auto *MD = dyn_cast<CXXMethodDecl>(C)) {
if ((MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) &&
if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(MD))
if (Ctor->isCopyOrMoveConstructor() && Ctor->isTrivial())
// Try to associate errors with the lexical context, if that is a function, or
// the value declaration otherwise.
FunctionDecl *FD = isa<FunctionDecl>(C) ? cast<FunctionDecl>(C)
: dyn_cast_or_null<FunctionDecl>(D);
auto CheckDeviceType = [&](QualType Ty) {
if (Ty->isDependentType())
if (Ty->isExtIntType()) {
if (!Context.getTargetInfo().hasExtIntType()) {
PartialDiagnostic PD = PDiag(diag::err_target_unsupported_type);
if (D)
PD << D;
PD << "expression";
targetDiag(Loc, PD, FD)
<< false /*show bit size*/ << 0 /*bitsize*/ << false /*return*/
<< Ty << Context.getTargetInfo().getTriple().str();
// Check if we are dealing with two 'long double' but with different
// semantics.
bool LongDoubleMismatched = false;
if (Ty->isRealFloatingType() && Context.getTypeSize(Ty) == 128) {
const llvm::fltSemantics &Sem = Context.getFloatTypeSemantics(Ty);
if ((&Sem != &llvm::APFloat::PPCDoubleDouble() &&
!Context.getTargetInfo().hasFloat128Type()) ||
(&Sem == &llvm::APFloat::PPCDoubleDouble() &&
LongDoubleMismatched = true;
if ((Ty->isFloat16Type() && !Context.getTargetInfo().hasFloat16Type()) ||
(Ty->isFloat128Type() && !Context.getTargetInfo().hasFloat128Type()) ||
(Ty->isIbm128Type() && !Context.getTargetInfo().hasIbm128Type()) ||
(Ty->isIntegerType() && Context.getTypeSize(Ty) == 128 &&
!Context.getTargetInfo().hasInt128Type()) ||
LongDoubleMismatched) {
PartialDiagnostic PD = PDiag(diag::err_target_unsupported_type);
if (D)
PD << D;
PD << "expression";
if (targetDiag(Loc, PD, FD)
<< true /*show bit size*/
<< static_cast<unsigned>(Context.getTypeSize(Ty)) << Ty
<< false /*return*/ << Context.getTargetInfo().getTriple().str()) {
if (D)
if (D)
targetDiag(D->getLocation(), diag::note_defined_here, FD) << D;
auto CheckType = [&](QualType Ty, bool IsRetTy = false) {
if (LangOpts.SYCLIsDevice || (LangOpts.OpenMP && LangOpts.OpenMPIsDevice))
QualType UnqualTy = Ty.getCanonicalType().getUnqualifiedType();
const TargetInfo &TI = Context.getTargetInfo();
if (!TI.hasLongDoubleType() && UnqualTy == Context.LongDoubleTy) {
PartialDiagnostic PD = PDiag(diag::err_target_unsupported_type);
if (D)
PD << D;
PD << "expression";
if (Diag(Loc, PD, FD)
<< false /*show bit size*/ << 0 << Ty << false /*return*/
<< Context.getTargetInfo().getTriple().str()) {
if (D)
if (D)
targetDiag(D->getLocation(), diag::note_defined_here, FD) << D;
bool IsDouble = UnqualTy == Context.DoubleTy;
bool IsFloat = UnqualTy == Context.FloatTy;
if (IsRetTy && !TI.hasFPReturn() && (IsDouble || IsFloat)) {
PartialDiagnostic PD = PDiag(diag::err_target_unsupported_type);
if (D)
PD << D;
PD << "expression";
if (Diag(Loc, PD, FD)
<< false /*show bit size*/ << 0 << Ty << true /*return*/
<< Context.getTargetInfo().getTriple().str()) {
if (D)
if (D)
targetDiag(D->getLocation(), diag::note_defined_here, FD) << D;
if (const auto *FPTy = dyn_cast<FunctionProtoType>(Ty)) {
for (const auto &ParamTy : FPTy->param_types())
CheckType(FPTy->getReturnType(), /*IsRetTy=*/true);
if (const auto *FNPTy = dyn_cast<FunctionNoProtoType>(Ty))
CheckType(FNPTy->getReturnType(), /*IsRetTy=*/true);
/// Looks through the macro-expansion chain for the given
/// location, looking for a macro expansion with the given name.
/// If one is found, returns true and sets the location to that
/// expansion loc.
bool Sema::findMacroSpelling(SourceLocation &locref, StringRef name) {
SourceLocation loc = locref;
if (!loc.isMacroID()) return false;
// There's no good way right now to look at the intermediate
// expansions, so just jump to the expansion location.
loc = getSourceManager().getExpansionLoc(loc);
// If that's written with the name, stop here.
SmallString<16> buffer;
if (getPreprocessor().getSpelling(loc, buffer) == name) {
locref = loc;
return true;
return false;
/// Determines the active Scope associated with the given declaration
/// context.
/// This routine maps a declaration context to the active Scope object that
/// represents that declaration context in the parser. It is typically used
/// from "scope-less" code (e.g., template instantiation, lazy creation of
/// declarations) that injects a name for name-lookup purposes and, therefore,
/// must update the Scope.
/// \returns The scope corresponding to the given declaraion context, or NULL
/// if no such scope is open.
Scope *Sema::getScopeForContext(DeclContext *Ctx) {
if (!Ctx)
return nullptr;
Ctx = Ctx->getPrimaryContext();
for (Scope *S = getCurScope(); S; S = S->getParent()) {
// Ignore scopes that cannot have declarations. This is important for
// out-of-line definitions of static class members.
if (S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope))
if (DeclContext *Entity = S->getEntity())
if (Ctx == Entity->getPrimaryContext())
return S;
return nullptr;
/// Enter a new function scope
void Sema::PushFunctionScope() {
if (FunctionScopes.empty() && CachedFunctionScope) {
// Use CachedFunctionScope to avoid allocating memory when possible.
} else {
FunctionScopes.push_back(new FunctionScopeInfo(getDiagnostics()));
if (LangOpts.OpenMP)
void Sema::PushBlockScope(Scope *BlockScope, BlockDecl *Block) {
FunctionScopes.push_back(new BlockScopeInfo(getDiagnostics(),
BlockScope, Block));
LambdaScopeInfo *Sema::PushLambdaScope() {
LambdaScopeInfo *const LSI = new LambdaScopeInfo(getDiagnostics());
return LSI;
void Sema::RecordParsingTemplateParameterDepth(unsigned Depth) {
if (LambdaScopeInfo *const LSI = getCurLambda()) {
LSI->AutoTemplateParameterDepth = Depth;
"Remove assertion if intentionally called in a non-lambda context.");
// Check that the type of the VarDecl has an accessible copy constructor and
// resolve its destructor's exception specification.
// This also performs initialization of block variables when they are moved
// to the heap. It uses the same rules as applicable for implicit moves
// according to the C++ standard in effect ([class.copy.elision]p3).
static void checkEscapingByref(VarDecl *VD, Sema &S) {
QualType T = VD->getType();
EnterExpressionEvaluationContext scope(
S, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
SourceLocation Loc = VD->getLocation();
Expr *VarRef =
new (S.Context) DeclRefExpr(S.Context, VD, false, T, VK_LValue, Loc);
ExprResult Result;
auto IE = InitializedEntity::InitializeBlock(Loc, T);
if (S.getLangOpts().CPlusPlus2b) {
auto *E = ImplicitCastExpr::Create(S.Context, T, CK_NoOp, VarRef, nullptr,
VK_XValue, FPOptionsOverride());
Result = S.PerformCopyInitialization(IE, SourceLocation(), E);
} else {
Result = S.PerformMoveOrCopyInitialization(
IE, Sema::NamedReturnInfo{VD, Sema::NamedReturnInfo::MoveEligible},
if (!Result.isInvalid()) {
Result = S.MaybeCreateExprWithCleanups(Result);
Expr *Init = Result.getAs<Expr>();
S.Context.setBlockVarCopyInit(VD, Init, S.canThrow(Init));
// The destructor's exception specification is needed when IRGen generates
// block copy/destroy functions. Resolve it here.
if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
if (CXXDestructorDecl *DD = RD->getDestructor()) {
auto *FPT = DD->getType()->getAs<FunctionProtoType>();
S.ResolveExceptionSpec(Loc, FPT);
static void markEscapingByrefs(const FunctionScopeInfo &FSI, Sema &S) {
// Set the EscapingByref flag of __block variables captured by
// escaping blocks.
for (const BlockDecl *BD : FSI.Blocks) {
for (const BlockDecl::Capture &BC : BD->captures()) {
VarDecl *VD = BC.getVariable();
if (VD->hasAttr<BlocksAttr>()) {
// Nothing to do if this is a __block variable captured by a
// non-escaping block.
if (BD->doesNotEscape())
// Check whether the captured variable is or contains an object of
// non-trivial C union type.
QualType CapType = BC.getVariable()->getType();
if (CapType.hasNonTrivialToPrimitiveDestructCUnion() ||
for (VarDecl *VD : FSI.ByrefBlockVars) {
// __block variables might require us to capture a copy-initializer.
if (!VD->isEscapingByref())
// It's currently invalid to ever have a __block variable with an
// array type; should we diagnose that here?
// Regardless, we don't want to ignore array nesting when
// constructing this copy.
if (VD->getType()->isStructureOrClassType())
checkEscapingByref(VD, S);
/// Pop a function (or block or lambda or captured region) scope from the stack.
/// \param WP The warning policy to use for CFG-based warnings, or null if such
/// warnings should not be produced.
/// \param D The declaration corresponding to this function scope, if producing
/// CFG-based warnings.
/// \param BlockType The type of the block expression, if D is a BlockDecl.
Sema::PopFunctionScopeInfo(const AnalysisBasedWarnings::Policy *WP,
const Decl *D, QualType BlockType) {
assert(!FunctionScopes.empty() && "mismatched push/pop!");
markEscapingByrefs(*FunctionScopes.back(), *this);
PoppedFunctionScopePtr Scope(FunctionScopes.pop_back_val(),
if (LangOpts.OpenMP)
// Issue any analysis-based warnings.
if (WP && D)
AnalysisWarnings.IssueWarnings(*WP, Scope.get(), D, BlockType);
for (const auto &PUD : Scope->PossiblyUnreachableDiags)
Diag(PUD.Loc, PUD.PD);
return Scope;
void Sema::PoppedFunctionScopeDeleter::
operator()(sema::FunctionScopeInfo *Scope) const {
// Stash the function scope for later reuse if it's for a normal function.
if (Scope->isPlainFunction() && !Self->CachedFunctionScope)
delete Scope;
void Sema::PushCompoundScope(bool IsStmtExpr) {
void Sema::PopCompoundScope() {
FunctionScopeInfo *CurFunction = getCurFunction();
assert(!CurFunction->CompoundScopes.empty() && "mismatched push/pop");
/// Determine whether any errors occurred within this function/method/
/// block.
bool Sema::hasAnyUnrecoverableErrorsInThisFunction() const {
return getCurFunction()->hasUnrecoverableErrorOccurred();
void Sema::setFunctionHasBranchIntoScope() {
if (!FunctionScopes.empty())
void Sema::setFunctionHasBranchProtectedScope() {
if (!FunctionScopes.empty())
void Sema::setFunctionHasIndirectGoto() {
if (!FunctionScopes.empty())
void Sema::setFunctionHasMustTail() {
if (!FunctionScopes.empty())
BlockScopeInfo *Sema::getCurBlock() {
if (FunctionScopes.empty())
return nullptr;
auto CurBSI = dyn_cast<BlockScopeInfo>(FunctionScopes.back());
if (CurBSI && CurBSI->TheDecl &&
!CurBSI->TheDecl->Encloses(CurContext)) {
// We have switched contexts due to template instantiation.
return nullptr;
return CurBSI;
FunctionScopeInfo *Sema::getEnclosingFunction() const {
if (FunctionScopes.empty())
return nullptr;
for (int e = FunctionScopes.size() - 1; e >= 0; --e) {
if (isa<sema::BlockScopeInfo>(FunctionScopes[e]))
return FunctionScopes[e];
return nullptr;
LambdaScopeInfo *Sema::getEnclosingLambda() const {
for (auto *Scope : llvm::reverse(FunctionScopes)) {
if (auto *LSI = dyn_cast<sema::LambdaScopeInfo>(Scope)) {
if (LSI->Lambda && !LSI->Lambda->Encloses(CurContext)) {
// We have switched contexts due to template instantiation.
// FIXME: We should swap out the FunctionScopes during code synthesis
// so that we don't need to check for this.
return nullptr;
return LSI;
return nullptr;
LambdaScopeInfo *Sema::getCurLambda(bool IgnoreNonLambdaCapturingScope) {
if (FunctionScopes.empty())
return nullptr;
auto I = FunctionScopes.rbegin();
if (IgnoreNonLambdaCapturingScope) {
auto E = FunctionScopes.rend();
while (I != E && isa<CapturingScopeInfo>(*I) && !isa<LambdaScopeInfo>(*I))
if (I == E)
return nullptr;
auto *CurLSI = dyn_cast<LambdaScopeInfo>(*I);
if (CurLSI && CurLSI->Lambda &&
!CurLSI->Lambda->Encloses(CurContext)) {
// We have switched contexts due to template instantiation.
return nullptr;
return CurLSI;
// We have a generic lambda if we parsed auto parameters, or we have
// an associated template parameter list.
LambdaScopeInfo *Sema::getCurGenericLambda() {
if (LambdaScopeInfo *LSI = getCurLambda()) {
return (LSI->TemplateParams.size() ||
LSI->GLTemplateParameterList) ? LSI : nullptr;
return nullptr;
void Sema::ActOnComment(SourceRange Comment) {
if (!LangOpts.RetainCommentsFromSystemHeaders &&
RawComment RC(SourceMgr, Comment, LangOpts.CommentOpts, false);
if (RC.isAlmostTrailingComment()) {
SourceRange MagicMarkerRange(Comment.getBegin(),
StringRef MagicMarkerText;
switch (RC.getKind()) {
case RawComment::RCK_OrdinaryBCPL:
MagicMarkerText = "///<";
case RawComment::RCK_OrdinaryC:
MagicMarkerText = "/**<";
llvm_unreachable("if this is an almost Doxygen comment, "
"it should be ordinary");
Diag(Comment.getBegin(), diag::warn_not_a_doxygen_trailing_member_comment) <<
FixItHint::CreateReplacement(MagicMarkerRange, MagicMarkerText);
// Pin this vtable to this file.
ExternalSemaSource::~ExternalSemaSource() {}
char ExternalSemaSource::ID;
void ExternalSemaSource::ReadMethodPool(Selector Sel) { }
void ExternalSemaSource::updateOutOfDateSelector(Selector Sel) { }
void ExternalSemaSource::ReadKnownNamespaces(
SmallVectorImpl<NamespaceDecl *> &Namespaces) {
void ExternalSemaSource::ReadUndefinedButUsed(
llvm::MapVector<NamedDecl *, SourceLocation> &Undefined) {}
void ExternalSemaSource::ReadMismatchingDeleteExpressions(llvm::MapVector<
FieldDecl *, llvm::SmallVector<std::pair<SourceLocation, bool>, 4>> &) {}
/// Figure out if an expression could be turned into a call.
/// Use this when trying to recover from an error where the programmer may have
/// written just the name of a function instead of actually calling it.
/// \param E - The expression to examine.
/// \param ZeroArgCallReturnTy - If the expression can be turned into a call
/// with no arguments, this parameter is set to the type returned by such a
/// call; otherwise, it is set to an empty QualType.
/// \param OverloadSet - If the expression is an overloaded function
/// name, this parameter is populated with the decls of the various overloads.
bool Sema::tryExprAsCall(Expr &E, QualType &ZeroArgCallReturnTy,
UnresolvedSetImpl &OverloadSet) {
ZeroArgCallReturnTy = QualType();
const OverloadExpr *Overloads = nullptr;
bool IsMemExpr = false;
if (E.getType() == Context.OverloadTy) {
OverloadExpr::FindResult FR = OverloadExpr::find(const_cast<Expr*>(&E));
// Ignore overloads that are pointer-to-member constants.
if (FR.HasFormOfMemberPointer)
return false;
Overloads = FR.Expression;
} else if (E.getType() == Context.BoundMemberTy) {
Overloads = dyn_cast<UnresolvedMemberExpr>(E.IgnoreParens());
IsMemExpr = true;
bool Ambiguous = false;
bool IsMV = false;
if (Overloads) {
for (OverloadExpr::decls_iterator it = Overloads->decls_begin(),
DeclsEnd = Overloads->decls_end(); it != DeclsEnd; ++it) {
// Check whether the function is a non-template, non-member which takes no
// arguments.
if (IsMemExpr)
if (const FunctionDecl *OverloadDecl
= dyn_cast<FunctionDecl>((*it)->getUnderlyingDecl())) {
if (OverloadDecl->getMinRequiredArguments() == 0) {
if (!ZeroArgCallReturnTy.isNull() && !Ambiguous &&
(!IsMV || !(OverloadDecl->isCPUDispatchMultiVersion() ||
OverloadDecl->isCPUSpecificMultiVersion()))) {
ZeroArgCallReturnTy = QualType();
Ambiguous = true;
} else {
ZeroArgCallReturnTy = OverloadDecl->getReturnType();
IsMV = OverloadDecl->isCPUDispatchMultiVersion() ||
// If it's not a member, use better machinery to try to resolve the call
if (!IsMemExpr)
return !ZeroArgCallReturnTy.isNull();
// Attempt to call the member with no arguments - this will correctly handle
// member templates with defaults/deduction of template arguments, overloads
// with default arguments, etc.
if (IsMemExpr && !E.isTypeDependent()) {
Sema::TentativeAnalysisScope Trap(*this);
ExprResult R = BuildCallToMemberFunction(nullptr, &E, SourceLocation(),
None, SourceLocation());
if (R.isUsable()) {
ZeroArgCallReturnTy = R.get()->getType();
return true;
return false;
if (const DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E.IgnoreParens())) {
if (const FunctionDecl *Fun = dyn_cast<FunctionDecl>(DeclRef->getDecl())) {
if (Fun->getMinRequiredArguments() == 0)
ZeroArgCallReturnTy = Fun->getReturnType();
return true;
// We don't have an expression that's convenient to get a FunctionDecl from,
// but we can at least check if the type is "function of 0 arguments".
QualType ExprTy = E.getType();
const FunctionType *FunTy = nullptr;
QualType PointeeTy = ExprTy->getPointeeType();
if (!PointeeTy.isNull())
FunTy = PointeeTy->getAs<FunctionType>();
if (!FunTy)
FunTy = ExprTy->getAs<FunctionType>();
if (const FunctionProtoType *FPT =
dyn_cast_or_null<FunctionProtoType>(FunTy)) {
if (FPT->getNumParams() == 0)
ZeroArgCallReturnTy = FunTy->getReturnType();
return true;
return false;
/// Give notes for a set of overloads.
/// A companion to tryExprAsCall. In cases when the name that the programmer
/// wrote was an overloaded function, we may be able to make some guesses about
/// plausible overloads based on their return types; such guesses can be handed
/// off to this method to be emitted as notes.
/// \param Overloads - The overloads to note.
/// \param FinalNoteLoc - If we've suppressed printing some overloads due to
/// -fshow-overloads=best, this is the location to attach to the note about too
/// many candidates. Typically this will be the location of the original
/// ill-formed expression.
static void noteOverloads(Sema &S, const UnresolvedSetImpl &Overloads,
const SourceLocation FinalNoteLoc) {
unsigned ShownOverloads = 0;
unsigned SuppressedOverloads = 0;
for (UnresolvedSetImpl::iterator It = Overloads.begin(),
DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
if (ShownOverloads >= S.Diags.getNumOverloadCandidatesToShow()) {
NamedDecl *Fn = (*It)->getUnderlyingDecl();
// Don't print overloads for non-default multiversioned functions.
if (const auto *FD = Fn->getAsFunction()) {
if (FD->isMultiVersion() && FD->hasAttr<TargetAttr>() &&
S.Diag(Fn->getLocation(), diag::note_possible_target_of_call);
if (SuppressedOverloads)
S.Diag(FinalNoteLoc, diag::note_ovl_too_many_candidates)
<< SuppressedOverloads;
static void notePlausibleOverloads(Sema &S, SourceLocation Loc,
const UnresolvedSetImpl &Overloads,
bool (*IsPlausibleResult)(QualType)) {
if (!IsPlausibleResult)
return noteOverloads(S, Overloads, Loc);
UnresolvedSet<2> PlausibleOverloads;
for (OverloadExpr::decls_iterator It = Overloads.begin(),
DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
const FunctionDecl *OverloadDecl = cast<FunctionDecl>(*It);
QualType OverloadResultTy = OverloadDecl->getReturnType();
if (IsPlausibleResult(OverloadResultTy))
noteOverloads(S, PlausibleOverloads, Loc);
/// Determine whether the given expression can be called by just
/// putting parentheses after it. Notably, expressions with unary
/// operators can't be because the unary operator will start parsing
/// outside the call.
static bool IsCallableWithAppend(Expr *E) {
E = E->IgnoreImplicit();
return (!isa<CStyleCastExpr>(E) &&
!isa<UnaryOperator>(E) &&
!isa<BinaryOperator>(E) &&
static bool IsCPUDispatchCPUSpecificMultiVersion(const Expr *E) {
if (const auto *UO = dyn_cast<UnaryOperator>(E))
E = UO->getSubExpr();
if (const auto *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
if (ULE->getNumDecls() == 0)
return false;
const NamedDecl *ND = *ULE->decls_begin();
if (const auto *FD = dyn_cast<FunctionDecl>(ND))
return FD->isCPUDispatchMultiVersion() || FD->isCPUSpecificMultiVersion();
return false;
bool Sema::tryToRecoverWithCall(ExprResult &E, const PartialDiagnostic &PD,
bool ForceComplain,
bool (*IsPlausibleResult)(QualType)) {
SourceLocation Loc = E.get()->getExprLoc();
SourceRange Range = E.get()->getSourceRange();
QualType ZeroArgCallTy;
UnresolvedSet<4> Overloads;
if (tryExprAsCall(*E.get(), ZeroArgCallTy, Overloads) &&
!ZeroArgCallTy.isNull() &&
(!IsPlausibleResult || IsPlausibleResult(ZeroArgCallTy))) {
// At this point, we know E is potentially callable with 0
// arguments and that it returns something of a reasonable type,
// so we can emit a fixit and carry on pretending that E was
// actually a CallExpr.
SourceLocation ParenInsertionLoc = getLocForEndOfToken(Range.getEnd());
bool IsMV = IsCPUDispatchCPUSpecificMultiVersion(E.get());
Diag(Loc, PD) << /*zero-arg*/ 1 << IsMV << Range
<< (IsCallableWithAppend(E.get())
? FixItHint::CreateInsertion(ParenInsertionLoc, "()")
: FixItHint());
if (!IsMV)
notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult);
// FIXME: Try this before emitting the fixit, and suppress diagnostics
// while doing so.
E = BuildCallExpr(nullptr, E.get(), Range.getEnd(), None,
return true;
if (!ForceComplain) return false;
bool IsMV = IsCPUDispatchCPUSpecificMultiVersion(E.get());
Diag(Loc, PD) << /*not zero-arg*/ 0 << IsMV << Range;
if (!IsMV)
notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult);
E = ExprError();
return true;
IdentifierInfo *Sema::getSuperIdentifier() const {
if (!Ident_super)
Ident_super = &Context.Idents.get("super");
return Ident_super;
IdentifierInfo *Sema::getFloat128Identifier() const {
if (!Ident___float128)
Ident___float128 = &Context.Idents.get("__float128");
return Ident___float128;
void Sema::PushCapturedRegionScope(Scope *S, CapturedDecl *CD, RecordDecl *RD,
CapturedRegionKind K,
unsigned OpenMPCaptureLevel) {
auto *CSI = new CapturedRegionScopeInfo(
getDiagnostics(), S, CD, RD, CD->getContextParam(), K,
(getLangOpts().OpenMP && K == CR_OpenMP) ? getOpenMPNestingLevel() : 0,
CSI->ReturnType = Context.VoidTy;
CapturedRegionScopeInfo *Sema::getCurCapturedRegion() {
if (FunctionScopes.empty())
return nullptr;
return dyn_cast<CapturedRegionScopeInfo>(FunctionScopes.back());
const llvm::MapVector<FieldDecl *, Sema::DeleteLocs> &
Sema::getMismatchingDeleteExpressions() const {
return DeleteExprs;