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//===--- Sema.h - Semantic Analysis & AST Building --------------*- C++ -*-===//
// 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 defines the Sema class, which performs semantic analysis and
// builds ASTs.
#include "clang/AST/ASTConcept.h"
#include "clang/AST/Attr.h"
#include "clang/AST/Availability.h"
#include "clang/AST/ComparisonCategories.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/DeclarationName.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprConcepts.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/ExternalASTSource.h"
#include "clang/AST/LocInfoType.h"
#include "clang/AST/MangleNumberingContext.h"
#include "clang/AST/NSAPI.h"
#include "clang/AST/PrettyPrinter.h"
#include "clang/AST/StmtCXX.h"
#include "clang/AST/TypeLoc.h"
#include "clang/AST/TypeOrdering.h"
#include "clang/Basic/BitmaskEnum.h"
#include "clang/Basic/ExpressionTraits.h"
#include "clang/Basic/Module.h"
#include "clang/Basic/OpenMPKinds.h"
#include "clang/Basic/PragmaKinds.h"
#include "clang/Basic/Specifiers.h"
#include "clang/Basic/TemplateKinds.h"
#include "clang/Basic/TypeTraits.h"
#include "clang/Sema/AnalysisBasedWarnings.h"
#include "clang/Sema/CleanupInfo.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/ExternalSemaSource.h"
#include "clang/Sema/IdentifierResolver.h"
#include "clang/Sema/ObjCMethodList.h"
#include "clang/Sema/Ownership.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/SemaConcept.h"
#include "clang/Sema/TypoCorrection.h"
#include "clang/Sema/Weak.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallBitVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/Frontend/OpenMP/OMPConstants.h"
#include <deque>
#include <memory>
#include <string>
#include <tuple>
#include <vector>
namespace llvm {
class APSInt;
template <typename ValueT> struct DenseMapInfo;
template <typename ValueT, typename ValueInfoT> class DenseSet;
class SmallBitVector;
struct InlineAsmIdentifierInfo;
namespace clang {
class ADLResult;
class ASTConsumer;
class ASTContext;
class ASTMutationListener;
class ASTReader;
class ASTWriter;
class ArrayType;
class ParsedAttr;
class BindingDecl;
class BlockDecl;
class CapturedDecl;
class CXXBasePath;
class CXXBasePaths;
class CXXBindTemporaryExpr;
typedef SmallVector<CXXBaseSpecifier*, 4> CXXCastPath;
class CXXConstructorDecl;
class CXXConversionDecl;
class CXXDeleteExpr;
class CXXDestructorDecl;
class CXXFieldCollector;
class CXXMemberCallExpr;
class CXXMethodDecl;
class CXXScopeSpec;
class CXXTemporary;
class CXXTryStmt;
class CallExpr;
class ClassTemplateDecl;
class ClassTemplatePartialSpecializationDecl;
class ClassTemplateSpecializationDecl;
class VarTemplatePartialSpecializationDecl;
class CodeCompleteConsumer;
class CodeCompletionAllocator;
class CodeCompletionTUInfo;
class CodeCompletionResult;
class CoroutineBodyStmt;
class Decl;
class DeclAccessPair;
class DeclContext;
class DeclRefExpr;
class DeclaratorDecl;
class DeducedTemplateArgument;
class DependentDiagnostic;
class DesignatedInitExpr;
class Designation;
class EnableIfAttr;
class EnumConstantDecl;
class Expr;
class ExtVectorType;
class FormatAttr;
class FriendDecl;
class FunctionDecl;
class FunctionProtoType;
class FunctionTemplateDecl;
class ImplicitConversionSequence;
typedef MutableArrayRef<ImplicitConversionSequence> ConversionSequenceList;
class InitListExpr;
class InitializationKind;
class InitializationSequence;
class InitializedEntity;
class IntegerLiteral;
class LabelStmt;
class LambdaExpr;
class LangOptions;
class LocalInstantiationScope;
class LookupResult;
class MacroInfo;
typedef ArrayRef<std::pair<IdentifierInfo *, SourceLocation>> ModuleIdPath;
class ModuleLoader;
class MultiLevelTemplateArgumentList;
class NamedDecl;
class ObjCCategoryDecl;
class ObjCCategoryImplDecl;
class ObjCCompatibleAliasDecl;
class ObjCContainerDecl;
class ObjCImplDecl;
class ObjCImplementationDecl;
class ObjCInterfaceDecl;
class ObjCIvarDecl;
template <class T> class ObjCList;
class ObjCMessageExpr;
class ObjCMethodDecl;
class ObjCPropertyDecl;
class ObjCProtocolDecl;
class OMPThreadPrivateDecl;
class OMPRequiresDecl;
class OMPDeclareReductionDecl;
class OMPDeclareSimdDecl;
class OMPClause;
struct OMPVarListLocTy;
struct OverloadCandidate;
enum class OverloadCandidateParamOrder : char;
enum OverloadCandidateRewriteKind : unsigned;
class OverloadCandidateSet;
class OverloadExpr;
class ParenListExpr;
class ParmVarDecl;
class Preprocessor;
class PseudoDestructorTypeStorage;
class PseudoObjectExpr;
class QualType;
class StandardConversionSequence;
class Stmt;
class StringLiteral;
class SwitchStmt;
class TemplateArgument;
class TemplateArgumentList;
class TemplateArgumentLoc;
class TemplateDecl;
class TemplateInstantiationCallback;
class TemplateParameterList;
class TemplatePartialOrderingContext;
class TemplateTemplateParmDecl;
class Token;
class TypeAliasDecl;
class TypedefDecl;
class TypedefNameDecl;
class TypeLoc;
class TypoCorrectionConsumer;
class UnqualifiedId;
class UnresolvedLookupExpr;
class UnresolvedMemberExpr;
class UnresolvedSetImpl;
class UnresolvedSetIterator;
class UsingDecl;
class UsingShadowDecl;
class ValueDecl;
class VarDecl;
class VarTemplateSpecializationDecl;
class VisibilityAttr;
class VisibleDeclConsumer;
class IndirectFieldDecl;
struct DeductionFailureInfo;
class TemplateSpecCandidateSet;
namespace sema {
class AccessedEntity;
class BlockScopeInfo;
class Capture;
class CapturedRegionScopeInfo;
class CapturingScopeInfo;
class CompoundScopeInfo;
class DelayedDiagnostic;
class DelayedDiagnosticPool;
class FunctionScopeInfo;
class LambdaScopeInfo;
class PossiblyUnreachableDiag;
class SemaPPCallbacks;
class TemplateDeductionInfo;
namespace threadSafety {
class BeforeSet;
void threadSafetyCleanup(BeforeSet* Cache);
// FIXME: No way to easily map from TemplateTypeParmTypes to
// TemplateTypeParmDecls, so we have this horrible PointerUnion.
typedef std::pair<llvm::PointerUnion<const TemplateTypeParmType*, NamedDecl*>,
SourceLocation> UnexpandedParameterPack;
/// Describes whether we've seen any nullability information for the given
/// file.
struct FileNullability {
/// The first pointer declarator (of any pointer kind) in the file that does
/// not have a corresponding nullability annotation.
SourceLocation PointerLoc;
/// The end location for the first pointer declarator in the file. Used for
/// placing fix-its.
SourceLocation PointerEndLoc;
/// Which kind of pointer declarator we saw.
uint8_t PointerKind;
/// Whether we saw any type nullability annotations in the given file.
bool SawTypeNullability = false;
/// A mapping from file IDs to a record of whether we've seen nullability
/// information in that file.
class FileNullabilityMap {
/// A mapping from file IDs to the nullability information for each file ID.
llvm::DenseMap<FileID, FileNullability> Map;
/// A single-element cache based on the file ID.
struct {
FileID File;
FileNullability Nullability;
} Cache;
FileNullability &operator[](FileID file) {
// Check the single-element cache.
if (file == Cache.File)
return Cache.Nullability;
// It's not in the single-element cache; flush the cache if we have one.
if (!Cache.File.isInvalid()) {
Map[Cache.File] = Cache.Nullability;
// Pull this entry into the cache.
Cache.File = file;
Cache.Nullability = Map[file];
return Cache.Nullability;
/// Keeps track of expected type during expression parsing. The type is tied to
/// a particular token, all functions that update or consume the type take a
/// start location of the token they are looking at as a parameter. This allows
/// to avoid updating the type on hot paths in the parser.
class PreferredTypeBuilder {
PreferredTypeBuilder() = default;
explicit PreferredTypeBuilder(QualType Type) : Type(Type) {}
void enterCondition(Sema &S, SourceLocation Tok);
void enterReturn(Sema &S, SourceLocation Tok);
void enterVariableInit(SourceLocation Tok, Decl *D);
/// Computing a type for the function argument may require running
/// overloading, so we postpone its computation until it is actually needed.
/// Clients should be very careful when using this funciton, as it stores a
/// function_ref, clients should make sure all calls to get() with the same
/// location happen while function_ref is alive.
void enterFunctionArgument(SourceLocation Tok,
llvm::function_ref<QualType()> ComputeType);
void enterParenExpr(SourceLocation Tok, SourceLocation LParLoc);
void enterUnary(Sema &S, SourceLocation Tok, tok::TokenKind OpKind,
SourceLocation OpLoc);
void enterBinary(Sema &S, SourceLocation Tok, Expr *LHS, tok::TokenKind Op);
void enterMemAccess(Sema &S, SourceLocation Tok, Expr *Base);
void enterSubscript(Sema &S, SourceLocation Tok, Expr *LHS);
/// Handles all type casts, including C-style cast, C++ casts, etc.
void enterTypeCast(SourceLocation Tok, QualType CastType);
QualType get(SourceLocation Tok) const {
if (Tok != ExpectedLoc)
return QualType();
if (!Type.isNull())
return Type;
if (ComputeType)
return ComputeType();
return QualType();
/// Start position of a token for which we store expected type.
SourceLocation ExpectedLoc;
/// Expected type for a token starting at ExpectedLoc.
QualType Type;
/// A function to compute expected type at ExpectedLoc. It is only considered
/// if Type is null.
llvm::function_ref<QualType()> ComputeType;
/// Sema - This implements semantic analysis and AST building for C.
class Sema final {
Sema(const Sema &) = delete;
void operator=(const Sema &) = delete;
/// A key method to reduce duplicate debug info from Sema.
virtual void anchor();
///Source of additional semantic information.
ExternalSemaSource *ExternalSource;
///Whether Sema has generated a multiplexer and has to delete it.
bool isMultiplexExternalSource;
static bool mightHaveNonExternalLinkage(const DeclaratorDecl *FD);
bool isVisibleSlow(const NamedDecl *D);
/// Determine whether two declarations should be linked together, given that
/// the old declaration might not be visible and the new declaration might
/// not have external linkage.
bool shouldLinkPossiblyHiddenDecl(const NamedDecl *Old,
const NamedDecl *New) {
if (isVisible(Old))
return true;
// See comment in below overload for why it's safe to compute the linkage
// of the new declaration here.
if (New->isExternallyDeclarable()) {
assert(Old->isExternallyDeclarable() &&
"should not have found a non-externally-declarable previous decl");
return true;
return false;
bool shouldLinkPossiblyHiddenDecl(LookupResult &Old, const NamedDecl *New);
void setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem,
QualType ResultTy,
ArrayRef<QualType> Args);
typedef OpaquePtr<DeclGroupRef> DeclGroupPtrTy;
typedef OpaquePtr<TemplateName> TemplateTy;
typedef OpaquePtr<QualType> TypeTy;
OpenCLOptions OpenCLFeatures;
FPOptions FPFeatures;
const LangOptions &LangOpts;
Preprocessor &PP;
ASTContext &Context;
ASTConsumer &Consumer;
DiagnosticsEngine &Diags;
SourceManager &SourceMgr;
/// Flag indicating whether or not to collect detailed statistics.
bool CollectStats;
/// Code-completion consumer.
CodeCompleteConsumer *CodeCompleter;
/// CurContext - This is the current declaration context of parsing.
DeclContext *CurContext;
/// Generally null except when we temporarily switch decl contexts,
/// like in \see ActOnObjCTemporaryExitContainerContext.
DeclContext *OriginalLexicalContext;
/// VAListTagName - The declaration name corresponding to __va_list_tag.
/// This is used as part of a hack to omit that class from ADL results.
DeclarationName VAListTagName;
bool MSStructPragmaOn; // True when \#pragma ms_struct on
/// Controls member pointer representation format under the MS ABI.
/// Stack of active SEH __finally scopes. Can be empty.
SmallVector<Scope*, 2> CurrentSEHFinally;
/// Source location for newly created implicit MSInheritanceAttrs
SourceLocation ImplicitMSInheritanceAttrLoc;
/// Holds TypoExprs that are created from `createDelayedTypo`. This is used by
/// `TransformTypos` in order to keep track of any TypoExprs that are created
/// recursively during typo correction and wipe them away if the correction
/// fails.
llvm::SmallVector<TypoExpr *, 2> TypoExprs;
/// pragma clang section kind
enum PragmaClangSectionKind {
PCSK_Invalid = 0,
PCSK_Data = 2,
PCSK_Rodata = 3,
PCSK_Text = 4,
PCSK_Relro = 5
enum PragmaClangSectionAction {
PCSA_Set = 0,
PCSA_Clear = 1
struct PragmaClangSection {
std::string SectionName;
bool Valid = false;
SourceLocation PragmaLocation;
void Act(SourceLocation PragmaLocation,
PragmaClangSectionAction Action,
StringLiteral* Name);
PragmaClangSection PragmaClangBSSSection;
PragmaClangSection PragmaClangDataSection;
PragmaClangSection PragmaClangRodataSection;
PragmaClangSection PragmaClangRelroSection;
PragmaClangSection PragmaClangTextSection;
enum PragmaMsStackAction {
PSK_Reset = 0x0, // #pragma ()
PSK_Set = 0x1, // #pragma (value)
PSK_Push = 0x2, // #pragma (push[, id])
PSK_Pop = 0x4, // #pragma (pop[, id])
PSK_Show = 0x8, // #pragma (show) -- only for "pack"!
PSK_Push_Set = PSK_Push | PSK_Set, // #pragma (push[, id], value)
PSK_Pop_Set = PSK_Pop | PSK_Set, // #pragma (pop[, id], value)
template<typename ValueType>
struct PragmaStack {
struct Slot {
llvm::StringRef StackSlotLabel;
ValueType Value;
SourceLocation PragmaLocation;
SourceLocation PragmaPushLocation;
Slot(llvm::StringRef StackSlotLabel, ValueType Value,
SourceLocation PragmaLocation, SourceLocation PragmaPushLocation)
: StackSlotLabel(StackSlotLabel), Value(Value),
PragmaPushLocation(PragmaPushLocation) {}
void Act(SourceLocation PragmaLocation,
PragmaMsStackAction Action,
llvm::StringRef StackSlotLabel,
ValueType Value);
// MSVC seems to add artificial slots to #pragma stacks on entering a C++
// method body to restore the stacks on exit, so it works like this:
// struct S {
// #pragma <name>(push, InternalPragmaSlot, <current_pragma_value>)
// void Method {}
// #pragma <name>(pop, InternalPragmaSlot)
// };
// It works even with #pragma vtordisp, although MSVC doesn't support
// #pragma vtordisp(push [, id], n)
// syntax.
// Push / pop a named sentinel slot.
void SentinelAction(PragmaMsStackAction Action, StringRef Label) {
assert((Action == PSK_Push || Action == PSK_Pop) &&
"Can only push / pop #pragma stack sentinels!");
Act(CurrentPragmaLocation, Action, Label, CurrentValue);
// Constructors.
explicit PragmaStack(const ValueType &Default)
: DefaultValue(Default), CurrentValue(Default) {}
bool hasValue() const { return CurrentValue != DefaultValue; }
SmallVector<Slot, 2> Stack;
ValueType DefaultValue; // Value used for PSK_Reset action.
ValueType CurrentValue;
SourceLocation CurrentPragmaLocation;
// FIXME: We should serialize / deserialize these if they occur in a PCH (but
// we shouldn't do so if they're in a module).
/// Whether to insert vtordisps prior to virtual bases in the Microsoft
/// C++ ABI. Possible values are 0, 1, and 2, which mean:
/// 0: Suppress all vtordisps
/// 1: Insert vtordisps in the presence of vbase overrides and non-trivial
/// structors
/// 2: Always insert vtordisps to support RTTI on partially constructed
/// objects
PragmaStack<MSVtorDispMode> VtorDispStack;
// #pragma pack.
// Sentinel to represent when the stack is set to mac68k alignment.
static const unsigned kMac68kAlignmentSentinel = ~0U;
PragmaStack<unsigned> PackStack;
// The current #pragma pack values and locations at each #include.
struct PackIncludeState {
unsigned CurrentValue;
SourceLocation CurrentPragmaLocation;
bool HasNonDefaultValue, ShouldWarnOnInclude;
SmallVector<PackIncludeState, 8> PackIncludeStack;
// Segment #pragmas.
PragmaStack<StringLiteral *> DataSegStack;
PragmaStack<StringLiteral *> BSSSegStack;
PragmaStack<StringLiteral *> ConstSegStack;
PragmaStack<StringLiteral *> CodeSegStack;
// RAII object to push / pop sentinel slots for all MS #pragma stacks.
// Actions should be performed only if we enter / exit a C++ method body.
class PragmaStackSentinelRAII {
PragmaStackSentinelRAII(Sema &S, StringRef SlotLabel, bool ShouldAct);
Sema &S;
StringRef SlotLabel;
bool ShouldAct;
/// A mapping that describes the nullability we've seen in each header file.
FileNullabilityMap NullabilityMap;
/// Last section used with #pragma init_seg.
StringLiteral *CurInitSeg;
SourceLocation CurInitSegLoc;
/// VisContext - Manages the stack for \#pragma GCC visibility.
void *VisContext; // Really a "PragmaVisStack*"
/// This an attribute introduced by \#pragma clang attribute.
struct PragmaAttributeEntry {
SourceLocation Loc;
ParsedAttr *Attribute;
SmallVector<attr::SubjectMatchRule, 4> MatchRules;
bool IsUsed;
/// A push'd group of PragmaAttributeEntries.
struct PragmaAttributeGroup {
/// The location of the push attribute.
SourceLocation Loc;
/// The namespace of this push group.
const IdentifierInfo *Namespace;
SmallVector<PragmaAttributeEntry, 2> Entries;
SmallVector<PragmaAttributeGroup, 2> PragmaAttributeStack;
/// The declaration that is currently receiving an attribute from the
/// #pragma attribute stack.
const Decl *PragmaAttributeCurrentTargetDecl;
/// This represents the last location of a "#pragma clang optimize off"
/// directive if such a directive has not been closed by an "on" yet. If
/// optimizations are currently "on", this is set to an invalid location.
SourceLocation OptimizeOffPragmaLocation;
/// Flag indicating if Sema is building a recovery call expression.
/// This flag is used to avoid building recovery call expressions
/// if Sema is already doing so, which would cause infinite recursions.
bool IsBuildingRecoveryCallExpr;
/// Used to control the generation of ExprWithCleanups.
CleanupInfo Cleanup;
/// ExprCleanupObjects - This is the stack of objects requiring
/// cleanup that are created by the current full expression. The
/// element type here is ExprWithCleanups::Object.
SmallVector<BlockDecl*, 8> ExprCleanupObjects;
/// Store a set of either DeclRefExprs or MemberExprs that contain a reference
/// to a variable (constant) that may or may not be odr-used in this Expr, and
/// we won't know until all lvalue-to-rvalue and discarded value conversions
/// have been applied to all subexpressions of the enclosing full expression.
/// This is cleared at the end of each full expression.
using MaybeODRUseExprSet = llvm::SmallPtrSet<Expr *, 2>;
MaybeODRUseExprSet MaybeODRUseExprs;
std::unique_ptr<sema::FunctionScopeInfo> CachedFunctionScope;
/// Stack containing information about each of the nested
/// function, block, and method scopes that are currently active.
SmallVector<sema::FunctionScopeInfo *, 4> FunctionScopes;
/// Stack containing information needed when in C++2a an 'auto' is encountered
/// in a function declaration parameter type specifier in order to invent a
/// corresponding template parameter in the enclosing abbreviated function
/// template. This information is also present in LambdaScopeInfo, stored in
/// the FunctionScopes stack.
SmallVector<InventedTemplateParameterInfo, 4> InventedParameterInfos;
typedef LazyVector<TypedefNameDecl *, ExternalSemaSource,
&ExternalSemaSource::ReadExtVectorDecls, 2, 2>
/// ExtVectorDecls - This is a list all the extended vector types. This allows
/// us to associate a raw vector type with one of the ext_vector type names.
/// This is only necessary for issuing pretty diagnostics.
ExtVectorDeclsType ExtVectorDecls;
/// FieldCollector - Collects CXXFieldDecls during parsing of C++ classes.
std::unique_ptr<CXXFieldCollector> FieldCollector;
typedef llvm::SmallSetVector<NamedDecl *, 16> NamedDeclSetType;
/// Set containing all declared private fields that are not used.
NamedDeclSetType UnusedPrivateFields;
/// Set containing all typedefs that are likely unused.
llvm::SmallSetVector<const TypedefNameDecl *, 4>
/// Delete-expressions to be analyzed at the end of translation unit
/// This list contains class members, and locations of delete-expressions
/// that could not be proven as to whether they mismatch with new-expression
/// used in initializer of the field.
typedef std::pair<SourceLocation, bool> DeleteExprLoc;
typedef llvm::SmallVector<DeleteExprLoc, 4> DeleteLocs;
llvm::MapVector<FieldDecl *, DeleteLocs> DeleteExprs;
typedef llvm::SmallPtrSet<const CXXRecordDecl*, 8> RecordDeclSetTy;
/// PureVirtualClassDiagSet - a set of class declarations which we have
/// emitted a list of pure virtual functions. Used to prevent emitting the
/// same list more than once.
std::unique_ptr<RecordDeclSetTy> PureVirtualClassDiagSet;
/// ParsingInitForAutoVars - a set of declarations with auto types for which
/// we are currently parsing the initializer.
llvm::SmallPtrSet<const Decl*, 4> ParsingInitForAutoVars;
/// Look for a locally scoped extern "C" declaration by the given name.
NamedDecl *findLocallyScopedExternCDecl(DeclarationName Name);
typedef LazyVector<VarDecl *, ExternalSemaSource,
&ExternalSemaSource::ReadTentativeDefinitions, 2, 2>
/// All the tentative definitions encountered in the TU.
TentativeDefinitionsType TentativeDefinitions;
/// All the external declarations encoutered and used in the TU.
SmallVector<VarDecl *, 4> ExternalDeclarations;
typedef LazyVector<const DeclaratorDecl *, ExternalSemaSource,
&ExternalSemaSource::ReadUnusedFileScopedDecls, 2, 2>
/// The set of file scoped decls seen so far that have not been used
/// and must warn if not used. Only contains the first declaration.
UnusedFileScopedDeclsType UnusedFileScopedDecls;
typedef LazyVector<CXXConstructorDecl *, ExternalSemaSource,
&ExternalSemaSource::ReadDelegatingConstructors, 2, 2>
/// All the delegating constructors seen so far in the file, used for
/// cycle detection at the end of the TU.
DelegatingCtorDeclsType DelegatingCtorDecls;
/// All the overriding functions seen during a class definition
/// that had their exception spec checks delayed, plus the overridden
/// function.
SmallVector<std::pair<const CXXMethodDecl*, const CXXMethodDecl*>, 2>
/// All the function redeclarations seen during a class definition that had
/// their exception spec checks delayed, plus the prior declaration they
/// should be checked against. Except during error recovery, the new decl
/// should always be a friend declaration, as that's the only valid way to
/// redeclare a special member before its class is complete.
SmallVector<std::pair<FunctionDecl*, FunctionDecl*>, 2>
typedef llvm::MapVector<const FunctionDecl *,
LateParsedTemplateMapT LateParsedTemplateMap;
/// Callback to the parser to parse templated functions when needed.
typedef void LateTemplateParserCB(void *P, LateParsedTemplate &LPT);
typedef void LateTemplateParserCleanupCB(void *P);
LateTemplateParserCB *LateTemplateParser;
LateTemplateParserCleanupCB *LateTemplateParserCleanup;
void *OpaqueParser;
void SetLateTemplateParser(LateTemplateParserCB *LTP,
LateTemplateParserCleanupCB *LTPCleanup,
void *P) {
LateTemplateParser = LTP;
LateTemplateParserCleanup = LTPCleanup;
OpaqueParser = P;
class DelayedDiagnostics;
class DelayedDiagnosticsState {
sema::DelayedDiagnosticPool *SavedPool;
friend class Sema::DelayedDiagnostics;
typedef DelayedDiagnosticsState ParsingDeclState;
typedef DelayedDiagnosticsState ProcessingContextState;
/// A class which encapsulates the logic for delaying diagnostics
/// during parsing and other processing.
class DelayedDiagnostics {
/// The current pool of diagnostics into which delayed
/// diagnostics should go.
sema::DelayedDiagnosticPool *CurPool;
DelayedDiagnostics() : CurPool(nullptr) {}
/// Adds a delayed diagnostic.
void add(const sema::DelayedDiagnostic &diag); // in DelayedDiagnostic.h
/// Determines whether diagnostics should be delayed.
bool shouldDelayDiagnostics() { return CurPool != nullptr; }
/// Returns the current delayed-diagnostics pool.
sema::DelayedDiagnosticPool *getCurrentPool() const {
return CurPool;
/// Enter a new scope. Access and deprecation diagnostics will be
/// collected in this pool.
DelayedDiagnosticsState push(sema::DelayedDiagnosticPool &pool) {
DelayedDiagnosticsState state;
state.SavedPool = CurPool;
CurPool = &pool;
return state;
/// Leave a delayed-diagnostic state that was previously pushed.
/// Do not emit any of the diagnostics. This is performed as part
/// of the bookkeeping of popping a pool "properly".
void popWithoutEmitting(DelayedDiagnosticsState state) {
CurPool = state.SavedPool;
/// Enter a new scope where access and deprecation diagnostics are
/// not delayed.
DelayedDiagnosticsState pushUndelayed() {
DelayedDiagnosticsState state;
state.SavedPool = CurPool;
CurPool = nullptr;
return state;
/// Undo a previous pushUndelayed().
void popUndelayed(DelayedDiagnosticsState state) {
assert(CurPool == nullptr);
CurPool = state.SavedPool;
} DelayedDiagnostics;
/// A RAII object to temporarily push a declaration context.
class ContextRAII {
Sema &S;
DeclContext *SavedContext;
ProcessingContextState SavedContextState;
QualType SavedCXXThisTypeOverride;
ContextRAII(Sema &S, DeclContext *ContextToPush, bool NewThisContext = true)
: S(S), SavedContext(S.CurContext),
assert(ContextToPush && "pushing null context");
S.CurContext = ContextToPush;
if (NewThisContext)
S.CXXThisTypeOverride = QualType();
void pop() {
if (!SavedContext) return;
S.CurContext = SavedContext;
S.CXXThisTypeOverride = SavedCXXThisTypeOverride;
SavedContext = nullptr;
~ContextRAII() {
/// Used to change context to isConstantEvaluated without pushing a heavy
/// ExpressionEvaluationContextRecord object.
bool isConstantEvaluatedOverride;
bool isConstantEvaluated() {
return ExprEvalContexts.back().isConstantEvaluated() ||
/// RAII object to handle the state changes required to synthesize
/// a function body.
class SynthesizedFunctionScope {
Sema &S;
Sema::ContextRAII SavedContext;
bool PushedCodeSynthesisContext = false;
SynthesizedFunctionScope(Sema &S, DeclContext *DC)
: S(S), SavedContext(S, DC) {
if (auto *FD = dyn_cast<FunctionDecl>(DC))
void addContextNote(SourceLocation UseLoc) {
Sema::CodeSynthesisContext Ctx;
Ctx.Kind = Sema::CodeSynthesisContext::DefiningSynthesizedFunction;
Ctx.PointOfInstantiation = UseLoc;
Ctx.Entity = cast<Decl>(S.CurContext);
PushedCodeSynthesisContext = true;
~SynthesizedFunctionScope() {
if (PushedCodeSynthesisContext)
if (auto *FD = dyn_cast<FunctionDecl>(S.CurContext))
/// WeakUndeclaredIdentifiers - Identifiers contained in
/// \#pragma weak before declared. rare. may alias another
/// identifier, declared or undeclared
llvm::MapVector<IdentifierInfo *, WeakInfo> WeakUndeclaredIdentifiers;
/// ExtnameUndeclaredIdentifiers - Identifiers contained in
/// \#pragma redefine_extname before declared. Used in Solaris system headers
/// to define functions that occur in multiple standards to call the version
/// in the currently selected standard.
llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*> ExtnameUndeclaredIdentifiers;
/// Load weak undeclared identifiers from the external source.
void LoadExternalWeakUndeclaredIdentifiers();
/// WeakTopLevelDecl - Translation-unit scoped declarations generated by
/// \#pragma weak during processing of other Decls.
/// I couldn't figure out a clean way to generate these in-line, so
/// we store them here and handle separately -- which is a hack.
/// It would be best to refactor this.
SmallVector<Decl*,2> WeakTopLevelDecl;
IdentifierResolver IdResolver;
/// Translation Unit Scope - useful to Objective-C actions that need
/// to lookup file scope declarations in the "ordinary" C decl namespace.
/// For example, user-defined classes, built-in "id" type, etc.
Scope *TUScope;
/// The C++ "std" namespace, where the standard library resides.
LazyDeclPtr StdNamespace;
/// The C++ "std::bad_alloc" class, which is defined by the C++
/// standard library.
LazyDeclPtr StdBadAlloc;
/// The C++ "std::align_val_t" enum class, which is defined by the C++
/// standard library.
LazyDeclPtr StdAlignValT;
/// The C++ "std::experimental" namespace, where the experimental parts
/// of the standard library resides.
NamespaceDecl *StdExperimentalNamespaceCache;
/// The C++ "std::initializer_list" template, which is defined in
/// \<initializer_list>.
ClassTemplateDecl *StdInitializerList;
/// The C++ "std::coroutine_traits" template, which is defined in
/// \<coroutine_traits>
ClassTemplateDecl *StdCoroutineTraitsCache;
/// The C++ "type_info" declaration, which is defined in \<typeinfo>.
RecordDecl *CXXTypeInfoDecl;
/// The MSVC "_GUID" struct, which is defined in MSVC header files.
RecordDecl *MSVCGuidDecl;
/// Caches identifiers/selectors for NSFoundation APIs.
std::unique_ptr<NSAPI> NSAPIObj;
/// The declaration of the Objective-C NSNumber class.
ObjCInterfaceDecl *NSNumberDecl;
/// The declaration of the Objective-C NSValue class.
ObjCInterfaceDecl *NSValueDecl;
/// Pointer to NSNumber type (NSNumber *).
QualType NSNumberPointer;
/// Pointer to NSValue type (NSValue *).
QualType NSValuePointer;
/// The Objective-C NSNumber methods used to create NSNumber literals.
ObjCMethodDecl *NSNumberLiteralMethods[NSAPI::NumNSNumberLiteralMethods];
/// The declaration of the Objective-C NSString class.
ObjCInterfaceDecl *NSStringDecl;
/// Pointer to NSString type (NSString *).
QualType NSStringPointer;
/// The declaration of the stringWithUTF8String: method.
ObjCMethodDecl *StringWithUTF8StringMethod;
/// The declaration of the valueWithBytes:objCType: method.
ObjCMethodDecl *ValueWithBytesObjCTypeMethod;
/// The declaration of the Objective-C NSArray class.
ObjCInterfaceDecl *NSArrayDecl;
/// The declaration of the arrayWithObjects:count: method.
ObjCMethodDecl *ArrayWithObjectsMethod;
/// The declaration of the Objective-C NSDictionary class.
ObjCInterfaceDecl *NSDictionaryDecl;
/// The declaration of the dictionaryWithObjects:forKeys:count: method.
ObjCMethodDecl *DictionaryWithObjectsMethod;
/// id<NSCopying> type.
QualType QIDNSCopying;
/// will hold 'respondsToSelector:'
Selector RespondsToSelectorSel;
/// A flag to remember whether the implicit forms of operator new and delete
/// have been declared.
bool GlobalNewDeleteDeclared;
/// A flag to indicate that we're in a context that permits abstract
/// references to fields. This is really a
bool AllowAbstractFieldReference;
/// Describes how the expressions currently being parsed are
/// evaluated at run-time, if at all.
enum class ExpressionEvaluationContext {
/// The current expression and its subexpressions occur within an
/// unevaluated operand (C++11 [expr]p7), such as the subexpression of
/// \c sizeof, where the type of the expression may be significant but
/// no code will be generated to evaluate the value of the expression at
/// run time.
/// The current expression occurs within a braced-init-list within
/// an unevaluated operand. This is mostly like a regular unevaluated
/// context, except that we still instantiate constexpr functions that are
/// referenced here so that we can perform narrowing checks correctly.
/// The current expression occurs within a discarded statement.
/// This behaves largely similarly to an unevaluated operand in preventing
/// definitions from being required, but not in other ways.
/// The current expression occurs within an unevaluated
/// operand that unconditionally permits abstract references to
/// fields, such as a SIZE operator in MS-style inline assembly.
/// The current context is "potentially evaluated" in C++11 terms,
/// but the expression is evaluated at compile-time (like the values of
/// cases in a switch statement).
/// The current expression is potentially evaluated at run time,
/// which means that code may be generated to evaluate the value of the
/// expression at run time.
/// The current expression is potentially evaluated, but any
/// declarations referenced inside that expression are only used if
/// in fact the current expression is used.
/// This value is used when parsing default function arguments, for which
/// we would like to provide diagnostics (e.g., passing non-POD arguments
/// through varargs) but do not want to mark declarations as "referenced"
/// until the default argument is used.
/// Data structure used to record current or nested
/// expression evaluation contexts.
struct ExpressionEvaluationContextRecord {
/// The expression evaluation context.
ExpressionEvaluationContext Context;
/// Whether the enclosing context needed a cleanup.
CleanupInfo ParentCleanup;
/// Whether we are in a decltype expression.
bool IsDecltype;
/// The number of active cleanup objects when we entered
/// this expression evaluation context.
unsigned NumCleanupObjects;
/// The number of typos encountered during this expression evaluation
/// context (i.e. the number of TypoExprs created).
unsigned NumTypos;
MaybeODRUseExprSet SavedMaybeODRUseExprs;
/// The lambdas that are present within this context, if it
/// is indeed an unevaluated context.
SmallVector<LambdaExpr *, 2> Lambdas;
/// The declaration that provides context for lambda expressions
/// and block literals if the normal declaration context does not
/// suffice, e.g., in a default function argument.
Decl *ManglingContextDecl;
/// If we are processing a decltype type, a set of call expressions
/// for which we have deferred checking the completeness of the return type.
SmallVector<CallExpr *, 8> DelayedDecltypeCalls;
/// If we are processing a decltype type, a set of temporary binding
/// expressions for which we have deferred checking the destructor.
SmallVector<CXXBindTemporaryExpr *, 8> DelayedDecltypeBinds;
llvm::SmallPtrSet<const Expr *, 8> PossibleDerefs;
/// Expressions appearing as the LHS of a volatile assignment in this
/// context. We produce a warning for these when popping the context if
/// they are not discarded-value expressions nor unevaluated operands.
SmallVector<Expr*, 2> VolatileAssignmentLHSs;
/// \brief Describes whether we are in an expression constext which we have
/// to handle differently.
enum ExpressionKind {
EK_Decltype, EK_TemplateArgument, EK_Other
} ExprContext;
ExpressionEvaluationContextRecord(ExpressionEvaluationContext Context,
unsigned NumCleanupObjects,
CleanupInfo ParentCleanup,
Decl *ManglingContextDecl,
ExpressionKind ExprContext)
: Context(Context), ParentCleanup(ParentCleanup),
NumCleanupObjects(NumCleanupObjects), NumTypos(0),
ManglingContextDecl(ManglingContextDecl), ExprContext(ExprContext) {}
bool isUnevaluated() const {
return Context == ExpressionEvaluationContext::Unevaluated ||
Context == ExpressionEvaluationContext::UnevaluatedAbstract ||
Context == ExpressionEvaluationContext::UnevaluatedList;
bool isConstantEvaluated() const {
return Context == ExpressionEvaluationContext::ConstantEvaluated;
/// A stack of expression evaluation contexts.
SmallVector<ExpressionEvaluationContextRecord, 8> ExprEvalContexts;
/// Emit a warning for all pending noderef expressions that we recorded.
void WarnOnPendingNoDerefs(ExpressionEvaluationContextRecord &Rec);
/// Compute the mangling number context for a lambda expression or
/// block literal. Also return the extra mangling decl if any.
/// \param DC - The DeclContext containing the lambda expression or
/// block literal.
std::tuple<MangleNumberingContext *, Decl *>
getCurrentMangleNumberContext(const DeclContext *DC);
/// SpecialMemberOverloadResult - The overloading result for a special member
/// function.
/// This is basically a wrapper around PointerIntPair. The lowest bits of the
/// integer are used to determine whether overload resolution succeeded.
class SpecialMemberOverloadResult {
enum Kind {
llvm::PointerIntPair<CXXMethodDecl*, 2> Pair;
SpecialMemberOverloadResult() : Pair() {}
SpecialMemberOverloadResult(CXXMethodDecl *MD)
: Pair(MD, MD->isDeleted() ? NoMemberOrDeleted : Success) {}
CXXMethodDecl *getMethod() const { return Pair.getPointer(); }
void setMethod(CXXMethodDecl *MD) { Pair.setPointer(MD); }
Kind getKind() const { return static_cast<Kind>(Pair.getInt()); }
void setKind(Kind K) { Pair.setInt(K); }
class SpecialMemberOverloadResultEntry
: public llvm::FastFoldingSetNode,
public SpecialMemberOverloadResult {
SpecialMemberOverloadResultEntry(const llvm::FoldingSetNodeID &ID)
: FastFoldingSetNode(ID)
/// A cache of special member function overload resolution results
/// for C++ records.
llvm::FoldingSet<SpecialMemberOverloadResultEntry> SpecialMemberCache;
/// A cache of the flags available in enumerations with the flag_bits
/// attribute.
mutable llvm::DenseMap<const EnumDecl*, llvm::APInt> FlagBitsCache;
/// The kind of translation unit we are processing.
/// When we're processing a complete translation unit, Sema will perform
/// end-of-translation-unit semantic tasks (such as creating
/// initializers for tentative definitions in C) once parsing has
/// completed. Modules and precompiled headers perform different kinds of
/// checks.
TranslationUnitKind TUKind;
llvm::BumpPtrAllocator BumpAlloc;
/// The number of SFINAE diagnostics that have been trapped.
unsigned NumSFINAEErrors;
typedef llvm::DenseMap<ParmVarDecl *, llvm::TinyPtrVector<ParmVarDecl *>>
/// A mapping from parameters with unparsed default arguments to the
/// set of instantiations of each parameter.
/// This mapping is a temporary data structure used when parsing
/// nested class templates or nested classes of class templates,
/// where we might end up instantiating an inner class before the
/// default arguments of its methods have been parsed.
UnparsedDefaultArgInstantiationsMap UnparsedDefaultArgInstantiations;
// Contains the locations of the beginning of unparsed default
// argument locations.
llvm::DenseMap<ParmVarDecl *, SourceLocation> UnparsedDefaultArgLocs;
/// UndefinedInternals - all the used, undefined objects which require a
/// definition in this translation unit.
llvm::MapVector<NamedDecl *, SourceLocation> UndefinedButUsed;
/// Determine if VD, which must be a variable or function, is an external
/// symbol that nonetheless can't be referenced from outside this translation
/// unit because its type has no linkage and it's not extern "C".
bool isExternalWithNoLinkageType(ValueDecl *VD);
/// Obtain a sorted list of functions that are undefined but ODR-used.
void getUndefinedButUsed(
SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> > &Undefined);
/// Retrieves list of suspicious delete-expressions that will be checked at
/// the end of translation unit.
const llvm::MapVector<FieldDecl *, DeleteLocs> &
getMismatchingDeleteExpressions() const;
typedef std::pair<ObjCMethodList, ObjCMethodList> GlobalMethods;
typedef llvm::DenseMap<Selector, GlobalMethods> GlobalMethodPool;
/// Method Pool - allows efficient lookup when typechecking messages to "id".
/// We need to maintain a list, since selectors can have differing signatures
/// across classes. In Cocoa, this happens to be extremely uncommon (only 1%
/// of selectors are "overloaded").
/// At the head of the list it is recorded whether there were 0, 1, or >= 2
/// methods inside categories with a particular selector.
GlobalMethodPool MethodPool;
/// Method selectors used in a \@selector expression. Used for implementation
/// of -Wselector.
llvm::MapVector<Selector, SourceLocation> ReferencedSelectors;
/// List of SourceLocations where 'self' is implicitly retained inside a
/// block.
llvm::SmallVector<std::pair<SourceLocation, const BlockDecl *>, 1>
/// Kinds of C++ special members.
enum CXXSpecialMember {
typedef llvm::PointerIntPair<CXXRecordDecl *, 3, CXXSpecialMember>
/// The C++ special members which we are currently in the process of
/// declaring. If this process recursively triggers the declaration of the
/// same special member, we should act as if it is not yet declared.
llvm::SmallPtrSet<SpecialMemberDecl, 4> SpecialMembersBeingDeclared;
/// Kinds of defaulted comparison operator functions.
enum class DefaultedComparisonKind : unsigned char {
/// This is not a defaultable comparison operator.
/// This is an operator== that should be implemented as a series of
/// subobject comparisons.
/// This is an operator<=> that should be implemented as a series of
/// subobject comparisons.
/// This is an operator!= that should be implemented as a rewrite in terms
/// of a == comparison.
/// This is an <, <=, >, or >= that should be implemented as a rewrite in
/// terms of a <=> comparison.
/// The function definitions which were renamed as part of typo-correction
/// to match their respective declarations. We want to keep track of them
/// to ensure that we don't emit a "redefinition" error if we encounter a
/// correctly named definition after the renamed definition.
llvm::SmallPtrSet<const NamedDecl *, 4> TypoCorrectedFunctionDefinitions;
/// Stack of types that correspond to the parameter entities that are
/// currently being copy-initialized. Can be empty.
llvm::SmallVector<QualType, 4> CurrentParameterCopyTypes;
void ReadMethodPool(Selector Sel);
void updateOutOfDateSelector(Selector Sel);
/// Private Helper predicate to check for 'self'.
bool isSelfExpr(Expr *RExpr);
bool isSelfExpr(Expr *RExpr, const ObjCMethodDecl *Method);
/// Cause the active diagnostic on the DiagosticsEngine to be
/// emitted. This is closely coupled to the SemaDiagnosticBuilder class and
/// should not be used elsewhere.
void EmitCurrentDiagnostic(unsigned DiagID);
/// Records and restores the FP_CONTRACT state on entry/exit of compound
/// statements.
class FPContractStateRAII {
FPContractStateRAII(Sema &S) : S(S), OldFPFeaturesState(S.FPFeatures) {}
~FPContractStateRAII() { S.FPFeatures = OldFPFeaturesState; }
Sema& S;
FPOptions OldFPFeaturesState;
void addImplicitTypedef(StringRef Name, QualType T);
bool WarnedStackExhausted = false;
Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
TranslationUnitKind TUKind = TU_Complete,
CodeCompleteConsumer *CompletionConsumer = nullptr);
/// Perform initialization that occurs after the parser has been
/// initialized but before it parses anything.
void Initialize();
const LangOptions &getLangOpts() const { return LangOpts; }
OpenCLOptions &getOpenCLOptions() { return OpenCLFeatures; }
FPOptions &getFPOptions() { return FPFeatures; }
DiagnosticsEngine &getDiagnostics() const { return Diags; }
SourceManager &getSourceManager() const { return SourceMgr; }
Preprocessor &getPreprocessor() const { return PP; }
ASTContext &getASTContext() const { return Context; }
ASTConsumer &getASTConsumer() const { return Consumer; }
ASTMutationListener *getASTMutationListener() const;
ExternalSemaSource* getExternalSource() const { return ExternalSource; }
///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 addExternalSource(ExternalSemaSource *E);
void PrintStats() const;
/// Warn that the stack is nearly exhausted.
void warnStackExhausted(SourceLocation Loc);
/// Run some code with "sufficient" stack space. (Currently, at least 256K is
/// guaranteed). Produces a warning if we're low on stack space and allocates
/// more in that case. Use this in code that may recurse deeply (for example,
/// in template instantiation) to avoid stack overflow.
void runWithSufficientStackSpace(SourceLocation Loc,
llvm::function_ref<void()> Fn);
/// Helper class that creates diagnostics with optional
/// template instantiation stacks.
/// This class provides a wrapper around the basic DiagnosticBuilder
/// class that emits diagnostics. SemaDiagnosticBuilder is
/// responsible for emitting the diagnostic (as DiagnosticBuilder
/// does) and, if the diagnostic comes from inside a template
/// instantiation, printing the template instantiation stack as
/// well.
class SemaDiagnosticBuilder : public DiagnosticBuilder {
Sema &SemaRef;
unsigned DiagID;
SemaDiagnosticBuilder(DiagnosticBuilder &DB, Sema &SemaRef, unsigned DiagID)
: DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) { }
// This is a cunning lie. DiagnosticBuilder actually performs move
// construction in its copy constructor (but due to varied uses, it's not
// possible to conveniently express this as actual move construction). So
// the default copy ctor here is fine, because the base class disables the
// source anyway, so the user-defined ~SemaDiagnosticBuilder is a safe no-op
// in that case anwyay.
SemaDiagnosticBuilder(const SemaDiagnosticBuilder&) = default;
~SemaDiagnosticBuilder() {
// If we aren't active, there is nothing to do.
if (!isActive()) return;
// Otherwise, we need to emit the diagnostic. First flush the underlying
// DiagnosticBuilder data, and clear the diagnostic builder itself so it
// won't emit the diagnostic in its own destructor.
// This seems wasteful, in that as written the DiagnosticBuilder dtor will
// do its own needless checks to see if the diagnostic needs to be
// emitted. However, because we take care to ensure that the builder
// objects never escape, a sufficiently smart compiler will be able to
// eliminate that code.
// Dispatch to Sema to emit the diagnostic.
/// Teach operator<< to produce an object of the correct type.
template<typename T>
friend const SemaDiagnosticBuilder &operator<<(
const SemaDiagnosticBuilder &Diag, const T &Value) {
const DiagnosticBuilder &BaseDiag = Diag;
BaseDiag << Value;
return Diag;
/// Emit a diagnostic.
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) {
DiagnosticBuilder DB = Diags.Report(Loc, DiagID);
return SemaDiagnosticBuilder(DB, *this, DiagID);
/// Emit a partial diagnostic.
SemaDiagnosticBuilder Diag(SourceLocation Loc, const PartialDiagnostic& PD);
/// Build a partial diagnostic.
PartialDiagnostic PDiag(unsigned DiagID = 0); // in SemaInternal.h
bool findMacroSpelling(SourceLocation &loc, StringRef name);
/// Get a string to suggest for zero-initialization of a type.
getFixItZeroInitializerForType(QualType T, SourceLocation Loc) const;
std::string getFixItZeroLiteralForType(QualType T, SourceLocation Loc) const;
/// Calls \c Lexer::getLocForEndOfToken()
SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset = 0);
/// Retrieve the module loader associated with the preprocessor.
ModuleLoader &getModuleLoader() const;
/// Invent a new identifier for parameters of abbreviated templates.
IdentifierInfo *
InventAbbreviatedTemplateParameterTypeName(IdentifierInfo *ParamName,
unsigned Index);
void emitAndClearUnusedLocalTypedefWarnings();
enum TUFragmentKind {
/// The global module fragment, between 'module;' and a module-declaration.
/// A normal translation unit fragment. For a non-module unit, this is the
/// entire translation unit. Otherwise, it runs from the module-declaration
/// to the private-module-fragment (if any) or the end of the TU (if not).
/// The private module fragment, between 'module :private;' and the end of
/// the translation unit.
void ActOnStartOfTranslationUnit();
void ActOnEndOfTranslationUnit();
void ActOnEndOfTranslationUnitFragment(TUFragmentKind Kind);
void CheckDelegatingCtorCycles();
Scope *getScopeForContext(DeclContext *Ctx);
void PushFunctionScope();
void PushBlockScope(Scope *BlockScope, BlockDecl *Block);
sema::LambdaScopeInfo *PushLambdaScope();
/// This is used to inform Sema what the current TemplateParameterDepth
/// is during Parsing. Currently it is used to pass on the depth
/// when parsing generic lambda 'auto' parameters.
void RecordParsingTemplateParameterDepth(unsigned Depth);
void PushCapturedRegionScope(Scope *RegionScope, CapturedDecl *CD,
RecordDecl *RD, CapturedRegionKind K,
unsigned OpenMPCaptureLevel = 0);
/// Custom deleter to allow FunctionScopeInfos to be kept alive for a short
/// time after they've been popped.
class PoppedFunctionScopeDeleter {
Sema *Self;
explicit PoppedFunctionScopeDeleter(Sema *Self) : Self(Self) {}
void operator()(sema::FunctionScopeInfo *Scope) const;
using PoppedFunctionScopePtr =
std::unique_ptr<sema::FunctionScopeInfo, PoppedFunctionScopeDeleter>;
PopFunctionScopeInfo(const sema::AnalysisBasedWarnings::Policy *WP = nullptr,
const Decl *D = nullptr,
QualType BlockType = QualType());
sema::FunctionScopeInfo *getCurFunction() const {
return FunctionScopes.empty() ? nullptr : FunctionScopes.back();
sema::FunctionScopeInfo *getEnclosingFunction() const;
void setFunctionHasBranchIntoScope();
void setFunctionHasBranchProtectedScope();
void setFunctionHasIndirectGoto();
void PushCompoundScope(bool IsStmtExpr);
void PopCompoundScope();
sema::CompoundScopeInfo &getCurCompoundScope() const;
bool hasAnyUnrecoverableErrorsInThisFunction() const;
/// Retrieve the current block, if any.
sema::BlockScopeInfo *getCurBlock();
/// Get the innermost lambda enclosing the current location, if any. This
/// looks through intervening non-lambda scopes such as local functions and
/// blocks.
sema::LambdaScopeInfo *getEnclosingLambda() const;
/// Retrieve the current lambda scope info, if any.
/// \param IgnoreNonLambdaCapturingScope true if should find the top-most
/// lambda scope info ignoring all inner capturing scopes that are not
/// lambda scopes.
sema::LambdaScopeInfo *
getCurLambda(bool IgnoreNonLambdaCapturingScope = false);
/// Retrieve the current generic lambda info, if any.
sema::LambdaScopeInfo *getCurGenericLambda();
/// Retrieve the current captured region, if any.
sema::CapturedRegionScopeInfo *getCurCapturedRegion();
/// WeakTopLevelDeclDecls - access to \#pragma weak-generated Decls
SmallVectorImpl<Decl *> &WeakTopLevelDecls() { return WeakTopLevelDecl; }
/// Called before parsing a function declarator belonging to a function
/// declaration.
void ActOnStartFunctionDeclarationDeclarator(Declarator &D,
unsigned TemplateParameterDepth);
/// Called after parsing a function declarator belonging to a function
/// declaration.
void ActOnFinishFunctionDeclarationDeclarator(Declarator &D);
void ActOnComment(SourceRange Comment);
// Type Analysis / Processing: SemaType.cpp.
QualType BuildQualifiedType(QualType T, SourceLocation Loc, Qualifiers Qs,
const DeclSpec *DS = nullptr);
QualType BuildQualifiedType(QualType T, SourceLocation Loc, unsigned CVRA,
const DeclSpec *DS = nullptr);
QualType BuildPointerType(QualType T,
SourceLocation Loc, DeclarationName Entity);
QualType BuildReferenceType(QualType T, bool LValueRef,
SourceLocation Loc, DeclarationName Entity);
QualType BuildArrayType(QualType T, ArrayType::ArraySizeModifier ASM,
Expr *ArraySize, unsigned Quals,
SourceRange Brackets, DeclarationName Entity);
QualType BuildVectorType(QualType T, Expr *VecSize, SourceLocation AttrLoc);
QualType BuildExtVectorType(QualType T, Expr *ArraySize,
SourceLocation AttrLoc);
QualType BuildAddressSpaceAttr(QualType &T, LangAS ASIdx, Expr *AddrSpace,
SourceLocation AttrLoc);
/// Same as above, but constructs the AddressSpace index if not provided.
QualType BuildAddressSpaceAttr(QualType &T, Expr *AddrSpace,
SourceLocation AttrLoc);
bool CheckQualifiedFunctionForTypeId(QualType T, SourceLocation Loc);
bool CheckFunctionReturnType(QualType T, SourceLocation Loc);
/// Build a function type.
/// This routine checks the function type according to C++ rules and
/// under the assumption that the result type and parameter types have
/// just been instantiated from a template. It therefore duplicates
/// some of the behavior of GetTypeForDeclarator, but in a much
/// simpler form that is only suitable for this narrow use case.
/// \param T The return type of the function.
/// \param ParamTypes The parameter types of the function. This array
/// will be modified to account for adjustments to the types of the
/// function parameters.
/// \param Loc The location of the entity whose type involves this
/// function type or, if there is no such entity, the location of the
/// type that will have function type.
/// \param Entity The name of the entity that involves the function
/// type, if known.
/// \param EPI Extra information about the function type. Usually this will
/// be taken from an existing function with the same prototype.
/// \returns A suitable function type, if there are no errors. The
/// unqualified type will always be a FunctionProtoType.
/// Otherwise, returns a NULL type.
QualType BuildFunctionType(QualType T,
MutableArrayRef<QualType> ParamTypes,
SourceLocation Loc, DeclarationName Entity,
const FunctionProtoType::ExtProtoInfo &EPI);
QualType BuildMemberPointerType(QualType T, QualType Class,
SourceLocation Loc,
DeclarationName Entity);
QualType BuildBlockPointerType(QualType T,
SourceLocation Loc, DeclarationName Entity);
QualType BuildParenType(QualType T);
QualType BuildAtomicType(QualType T, SourceLocation Loc);
QualType BuildReadPipeType(QualType T,
SourceLocation Loc);
QualType BuildWritePipeType(QualType T,
SourceLocation Loc);
TypeSourceInfo *GetTypeForDeclarator(Declarator &D, Scope *S);
TypeSourceInfo *GetTypeForDeclaratorCast(Declarator &D, QualType FromTy);
/// Package the given type and TSI into a ParsedType.
ParsedType CreateParsedType(QualType T, TypeSourceInfo *TInfo);
DeclarationNameInfo GetNameForDeclarator(Declarator &D);
DeclarationNameInfo GetNameFromUnqualifiedId(const UnqualifiedId &Name);
static QualType GetTypeFromParser(ParsedType Ty,
TypeSourceInfo **TInfo = nullptr);
CanThrowResult canThrow(const Stmt *E);
const FunctionProtoType *ResolveExceptionSpec(SourceLocation Loc,
const FunctionProtoType *FPT);
void UpdateExceptionSpec(FunctionDecl *FD,
const FunctionProtoType::ExceptionSpecInfo &ESI);
bool CheckSpecifiedExceptionType(QualType &T, SourceRange Range);
bool CheckDistantExceptionSpec(QualType T);
bool CheckEquivalentExceptionSpec(FunctionDecl *Old, FunctionDecl *New);
bool CheckEquivalentExceptionSpec(
const FunctionProtoType *Old, SourceLocation OldLoc,
const FunctionProtoType *New, SourceLocation NewLoc);
bool CheckEquivalentExceptionSpec(
const PartialDiagnostic &DiagID, const PartialDiagnostic & NoteID,
const FunctionProtoType *Old, SourceLocation OldLoc,
const FunctionProtoType *New, SourceLocation NewLoc);
bool handlerCanCatch(QualType HandlerType, QualType ExceptionType);
bool CheckExceptionSpecSubset(const PartialDiagnostic &DiagID,
const PartialDiagnostic &NestedDiagID,
const PartialDiagnostic &NoteID,
const PartialDiagnostic &NoThrowDiagID,
const FunctionProtoType *Superset,
SourceLocation SuperLoc,
const FunctionProtoType *Subset,
SourceLocation SubLoc);
bool CheckParamExceptionSpec(const PartialDiagnostic &NestedDiagID,
const PartialDiagnostic &NoteID,
const FunctionProtoType *Target,
SourceLocation TargetLoc,
const FunctionProtoType *Source,
SourceLocation SourceLoc);
TypeResult ActOnTypeName(Scope *S, Declarator &D);
/// The parser has parsed the context-sensitive type 'instancetype'
/// in an Objective-C message declaration. Return the appropriate type.
ParsedType ActOnObjCInstanceType(SourceLocation Loc);
/// Abstract class used to diagnose incomplete types.
struct TypeDiagnoser {
TypeDiagnoser() {}
virtual void diagnose(Sema &S, SourceLocation Loc, QualType T) = 0;
virtual ~TypeDiagnoser() {}
static int getPrintable(int I) { return I; }
static unsigned getPrintable(unsigned I) { return I; }
static bool getPrintable(bool B) { return B; }
static const char * getPrintable(const char *S) { return S; }
static StringRef getPrintable(StringRef S) { return S; }
static const std::string &getPrintable(const std::string &S) { return S; }
static const IdentifierInfo *getPrintable(const IdentifierInfo *II) {
return II;
static DeclarationName getPrintable(DeclarationName N) { return N; }
static QualType getPrintable(QualType T) { return T; }
static SourceRange getPrintable(SourceRange R) { return R; }
static SourceRange getPrintable(SourceLocation L) { return L; }
static SourceRange getPrintable(const Expr *E) { return E->getSourceRange(); }
static SourceRange getPrintable(TypeLoc TL) { return TL.getSourceRange();}
template <typename... Ts> class BoundTypeDiagnoser : public TypeDiagnoser {
unsigned DiagID;
std::tuple<const Ts &...> Args;
template <std::size_t... Is>
void emit(const SemaDiagnosticBuilder &DB,
std::index_sequence<Is...>) const {
// Apply all tuple elements to the builder in order.
bool Dummy[] = {false, (DB << getPrintable(std::get<Is>(Args)))...};
BoundTypeDiagnoser(unsigned DiagID, const Ts &...Args)
: TypeDiagnoser(), DiagID(DiagID), Args(Args...) {
assert(DiagID != 0 && "no diagnostic for type diagnoser");
void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
const SemaDiagnosticBuilder &DB = S.Diag(Loc, DiagID);
emit(DB, std::index_sequence_for<Ts...>());
DB << T;
/// Methods for marking which expressions involve dereferencing a pointer
/// marked with the 'noderef' attribute. Expressions are checked bottom up as
/// they are parsed, meaning that a noderef pointer may not be accessed. For
/// example, in `&*p` where `p` is a noderef pointer, we will first parse the
/// `*p`, but need to check that `address of` is called on it. This requires
/// keeping a container of all pending expressions and checking if the address
/// of them are eventually taken.
void CheckSubscriptAccessOfNoDeref(const ArraySubscriptExpr *E);
void CheckAddressOfNoDeref(const Expr *E);
void CheckMemberAccessOfNoDeref(const MemberExpr *E);
bool RequireCompleteTypeImpl(SourceLocation Loc, QualType T,
TypeDiagnoser *Diagnoser);
struct ModuleScope {
SourceLocation BeginLoc;
clang::Module *Module = nullptr;
bool ModuleInterface = false;
bool ImplicitGlobalModuleFragment = false;
VisibleModuleSet OuterVisibleModules;
/// The modules we're currently parsing.
llvm::SmallVector<ModuleScope, 16> ModuleScopes;
/// Namespace definitions that we will export when they finish.
llvm::SmallPtrSet<const NamespaceDecl*, 8> DeferredExportedNamespaces;
/// Get the module whose scope we are currently within.
Module *getCurrentModule() const {
return ModuleScopes.empty() ? nullptr : ModuleScopes.back().Module;
VisibleModuleSet VisibleModules;
/// Get the module owning an entity.
Module *getOwningModule(const Decl *Entity) {
return Entity->getOwningModule();
/// Make a merged definition of an existing hidden definition \p ND
/// visible at the specified location.
void makeMergedDefinitionVisible(NamedDecl *ND);
bool isModuleVisible(const Module *M, bool ModulePrivate = false);
/// Determine whether a declaration is visible to name lookup.
bool isVisible(const NamedDecl *D) {
return !D->isHidden() || isVisibleSlow(D);
/// Determine whether any declaration of an entity is visible.
hasVisibleDeclaration(const NamedDecl *D,
llvm::SmallVectorImpl<Module *> *Modules = nullptr) {
return isVisible(D) || hasVisibleDeclarationSlow(D, Modules);
bool hasVisibleDeclarationSlow(const NamedDecl *D,
llvm::SmallVectorImpl<Module *> *Modules);
bool hasVisibleMergedDefinition(NamedDecl *Def);
bool hasMergedDefinitionInCurrentModule(NamedDecl *Def);
/// Determine if \p D and \p Suggested have a structurally compatible
/// layout as described in C11 6.2.7/1.
bool hasStructuralCompatLayout(Decl *D, Decl *Suggested);
/// Determine if \p D has a visible definition. If not, suggest a declaration
/// that should be made visible to expose the definition.
bool hasVisibleDefinition(NamedDecl *D, NamedDecl **Suggested,
bool OnlyNeedComplete = false);
bool hasVisibleDefinition(const NamedDecl *D) {
NamedDecl *Hidden;
return hasVisibleDefinition(const_cast<NamedDecl*>(D), &Hidden);
/// Determine if the template parameter \p D has a visible default argument.
hasVisibleDefaultArgument(const NamedDecl *D,
llvm::SmallVectorImpl<Module *> *Modules = nullptr);
/// Determine if there is a visible declaration of \p D that is an explicit
/// specialization declaration for a specialization of a template. (For a
/// member specialization, use hasVisibleMemberSpecialization.)
bool hasVisibleExplicitSpecialization(
const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules = nullptr);
/// Determine if there is a visible declaration of \p D that is a member
/// specialization declaration (as opposed to an instantiated declaration).
bool hasVisibleMemberSpecialization(
const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules = nullptr);
/// Determine if \p A and \p B are equivalent internal linkage declarations
/// from different modules, and thus an ambiguity error can be downgraded to
/// an extension warning.
bool isEquivalentInternalLinkageDeclaration(const NamedDecl *A,
const NamedDecl *B);
void diagnoseEquivalentInternalLinkageDeclarations(
SourceLocation Loc, const NamedDecl *D,
ArrayRef<const NamedDecl *> Equiv);
bool isUsualDeallocationFunction(const CXXMethodDecl *FD);
bool isCompleteType(SourceLocation Loc, QualType T) {
return !RequireCompleteTypeImpl(Loc, T, nullptr);
bool RequireCompleteType(SourceLocation Loc, QualType T,
TypeDiagnoser &Diagnoser);
bool RequireCompleteType(SourceLocation Loc, QualType T,
unsigned DiagID);
template <typename... Ts>
bool RequireCompleteType(SourceLocation Loc, QualType T, unsigned DiagID,
const Ts &...Args) {
BoundTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
return RequireCompleteType(Loc, T, Diagnoser);
void completeExprArrayBound(Expr *E);
bool RequireCompleteExprType(Expr *E, TypeDiagnoser &Diagnoser);
bool RequireCompleteExprType(Expr *E, unsigned DiagID);
template <typename... Ts>
bool RequireCompleteExprType(Expr *E, unsigned DiagID, const Ts &...Args) {
BoundTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
return RequireCompleteExprType(E, Diagnoser);
bool RequireLiteralType(SourceLocation Loc, QualType T,
TypeDiagnoser &Diagnoser);
bool RequireLiteralType(SourceLocation Loc, QualType T, unsigned DiagID);
template <typename... Ts>
bool RequireLiteralType(SourceLocation Loc, QualType T, unsigned DiagID,
const Ts &...Args) {
BoundTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
return RequireLiteralType(Loc, T, Diagnoser);
QualType getElaboratedType(ElaboratedTypeKeyword Keyword,
const CXXScopeSpec &SS, QualType T,
TagDecl *OwnedTagDecl = nullptr);
QualType BuildTypeofExprType(Expr *E, SourceLocation Loc);
/// If AsUnevaluated is false, E is treated as though it were an evaluated
/// context, such as when building a type for decltype(auto).
QualType BuildDecltypeType(Expr *E, SourceLocation Loc,
bool AsUnevaluated = true);
QualType BuildUnaryTransformType(QualType BaseType,
UnaryTransformType::UTTKind UKind,
SourceLocation Loc);
// Symbol table / Decl tracking callbacks: SemaDecl.cpp.
struct SkipBodyInfo {
: ShouldSkip(false), CheckSameAsPrevious(false), Previous(nullptr),
New(nullptr) {}
bool ShouldSkip;
bool CheckSameAsPrevious;
NamedDecl *Previous;
NamedDecl *New;
DeclGroupPtrTy ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType = nullptr);
void DiagnoseUseOfUnimplementedSelectors();
bool isSimpleTypeSpecifier(tok::TokenKind Kind) const;
ParsedType getTypeName(const IdentifierInfo &II, SourceLocation NameLoc,
Scope *S, CXXScopeSpec *SS = nullptr,
bool isClassName = false, bool HasTrailingDot = false,
ParsedType ObjectType = nullptr,
bool IsCtorOrDtorName = false,
bool WantNontrivialTypeSourceInfo = false,
bool IsClassTemplateDeductionContext = true,
IdentifierInfo **CorrectedII = nullptr);
TypeSpecifierType isTagName(IdentifierInfo &II, Scope *S);
bool isMicrosoftMissingTypename(const CXXScopeSpec *SS, Scope *S);
void DiagnoseUnknownTypeName(IdentifierInfo *&II,
SourceLocation IILoc,
Scope *S,
CXXScopeSpec *SS,
ParsedType &SuggestedType,
bool IsTemplateName = false);
/// Attempt to behave like MSVC in situations where lookup of an unqualified
/// type name has failed in a dependent context. In these situations, we
/// automatically form a DependentTypeName that will retry lookup in a related
/// scope during instantiation.
ParsedType ActOnMSVCUnknownTypeName(const IdentifierInfo &II,
SourceLocation NameLoc,
bool IsTemplateTypeArg);
/// Describes the result of the name lookup and resolution performed
/// by \c ClassifyName().
enum NameClassificationKind {
/// This name is not a type or template in this context, but might be
/// something else.
/// Classification failed; an error has been produced.
/// The name has been typo-corrected to a keyword.
/// The name was classified as a type.
/// The name was classified as a specific non-type, non-template
/// declaration. ActOnNameClassifiedAsNonType should be called to
/// convert the declaration to an expression.
/// The name was classified as an ADL-only function name.
/// ActOnNameClassifiedAsUndeclaredNonType should be called to convert the
/// result to an expression.
/// The name denotes a member of a dependent type that could not be
/// resolved. ActOnNameClassifiedAsDependentNonType should be called to
/// convert the result to an expression.
/// The name was classified as a non-type, and an expression representing
/// that name has been formed.
/// The name was classified as a template whose specializations are types.
/// The name was classified as a variable template name.
/// The name was classified as a function template name.
/// The name was classified as an ADL-only function template name.
/// The name was classified as a concept name.
class NameClassification {
NameClassificationKind Kind;
union {
ExprResult Expr;
NamedDecl *NonTypeDecl;
TemplateName Template;
ParsedType Type;
explicit NameClassification(NameClassificationKind Kind) : Kind(Kind) {}
NameClassification(ParsedType Type) : Kind(NC_Type), Type(Type) {}
NameClassification(const IdentifierInfo *Keyword) : Kind(NC_Keyword) {}
static NameClassification Error() {
return NameClassification(NC_Error);
static NameClassification Unknown() {
return NameClassification(NC_Unknown);
static NameClassification ContextIndependentExpr(ExprResult E) {
NameClassification Result(NC_ContextIndependentExpr);
Result.Expr = E;
return Result;
static NameClassification NonType(NamedDecl *D) {
NameClassification Result(NC_NonType);
Result.NonTypeDecl = D;
return Result;
static NameClassification UndeclaredNonType() {
return NameClassification(NC_UndeclaredNonType);
static NameClassification DependentNonType() {
return NameClassification(NC_DependentNonType);
static NameClassification TypeTemplate(TemplateName Name) {
NameClassification Result(NC_TypeTemplate);
Result.Template = Name;
return Result;
static NameClassification VarTemplate(TemplateName Name) {
NameClassification Result(NC_VarTemplate);
Result.Template = Name;
return Result;
static NameClassification FunctionTemplate(TemplateName Name) {
NameClassification Result(NC_FunctionTemplate);
Result.Template = Name;
return Result;
static NameClassification Concept(TemplateName Name) {
NameClassification Result(NC_Concept);
Result.Template = Name;
return Result;
static NameClassification UndeclaredTemplate(TemplateName Name) {
NameClassification Result(NC_UndeclaredTemplate);
Result.Template = Name;
return Result;
NameClassificationKind getKind() const { return Kind; }
ExprResult getExpression() const {
assert(Kind == NC_ContextIndependentExpr);
return Expr;
ParsedType getType() const {
assert(Kind == NC_Type);
return Type;
NamedDecl *getNonTypeDecl() const {
assert(Kind == NC_NonType);
return NonTypeDecl;
TemplateName getTemplateName() const {
assert(Kind == NC_TypeTemplate || Kind == NC_FunctionTemplate ||
Kind == NC_VarTemplate || Kind == NC_Concept ||
Kind == NC_UndeclaredTemplate);
return Template;
TemplateNameKind getTemplateNameKind() const {
switch (Kind) {
case NC_TypeTemplate:
return TNK_Type_template;
case NC_FunctionTemplate:
return TNK_Function_template;
case NC_VarTemplate:
return TNK_Var_template;
case NC_Concept:
return TNK_Concept_template;
case NC_UndeclaredTemplate:
return TNK_Undeclared_template;
llvm_unreachable("unsupported name classification.");
/// Perform name lookup on the given name, classifying it based on
/// the results of name lookup and the following token.
/// This routine is used by the parser to resolve identifiers and help direct
/// parsing. When the identifier cannot be found, this routine will attempt
/// to correct the typo and classify based on the resulting name.
/// \param S The scope in which we're performing name lookup.
/// \param SS The nested-name-specifier that precedes the name.
/// \param Name The identifier. If typo correction finds an alternative name,
/// this pointer parameter will be updated accordingly.
/// \param NameLoc The location of the identifier.
/// \param NextToken The token following the identifier. Used to help
/// disambiguate the name.
/// \param CCC The correction callback, if typo correction is desired.
NameClassification ClassifyName(Scope *S, CXXScopeSpec &SS,
IdentifierInfo *&Name, SourceLocation NameLoc,
const Token &NextToken,
CorrectionCandidateCallback *CCC = nullptr);
/// Act on the result of classifying a name as an undeclared (ADL-only)
/// non-type declaration.
ExprResult ActOnNameClassifiedAsUndeclaredNonType(IdentifierInfo *Name,
SourceLocation NameLoc);
/// Act on the result of classifying a name as an undeclared member of a
/// dependent base class.
ExprResult ActOnNameClassifiedAsDependentNonType(const CXXScopeSpec &SS,
IdentifierInfo *Name,
SourceLocation NameLoc,
bool IsAddressOfOperand);
/// Act on the result of classifying a name as a specific non-type
/// declaration.
ExprResult ActOnNameClassifiedAsNonType(Scope *S, const CXXScopeSpec &SS,
NamedDecl *Found,
SourceLocation NameLoc,
const Token &NextToken);
/// Describes the detailed kind of a template name. Used in diagnostics.
enum class TemplateNameKindForDiagnostics {
getTemplateNameKindForDiagnostics(TemplateName Name);
/// Determine whether it's plausible that E was intended to be a
/// template-name.
bool mightBeIntendedToBeTemplateName(ExprResult E, bool &Dependent) {
if (!getLangOpts().CPlusPlus || E.isInvalid())
return false;
Dependent = false;
if (auto *DRE = dyn_cast<DeclRefExpr>(E.get()))
return !DRE->hasExplicitTemplateArgs();
if (auto *ME = dyn_cast<MemberExpr>(E.get()))
return !ME->hasExplicitTemplateArgs();
Dependent = true;
if (auto *DSDRE = dyn_cast<DependentScopeDeclRefExpr>(E.get()))
return !DSDRE->hasExplicitTemplateArgs();
if (auto *DSME = dyn_cast<CXXDependentScopeMemberExpr>(E.get()))
return !DSME->hasExplicitTemplateArgs();
// Any additional cases recognized here should also be handled by
// diagnoseExprIntendedAsTemplateName.
return false;
void diagnoseExprIntendedAsTemplateName(Scope *S, ExprResult TemplateName,
SourceLocation Less,
SourceLocation Greater);
Decl *ActOnDeclarator(Scope *S, Declarator &D);
NamedDecl *HandleDeclarator(Scope *S, Declarator &D,
MultiTemplateParamsArg TemplateParameterLists);
void RegisterLocallyScopedExternCDecl(NamedDecl *ND, Scope *S);
bool DiagnoseClassNameShadow(DeclContext *DC, DeclarationNameInfo Info);
bool diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
DeclarationName Name, SourceLocation Loc,
bool IsTemplateId);
diagnoseIgnoredQualifiers(unsigned DiagID, unsigned Quals,
SourceLocation FallbackLoc,
SourceLocation ConstQualLoc = SourceLocation(),
SourceLocation VolatileQualLoc = SourceLocation(),
SourceLocation RestrictQualLoc = SourceLocation(),
SourceLocation AtomicQualLoc = SourceLocation(),
SourceLocation UnalignedQualLoc = SourceLocation());
static bool adjustContextForLocalExternDecl(DeclContext *&DC);
void DiagnoseFunctionSpecifiers(const DeclSpec &DS);
NamedDecl *getShadowedDeclaration(const TypedefNameDecl *D,
const LookupResult &R);
NamedDecl *getShadowedDeclaration(const VarDecl *D, const LookupResult &R);
void CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl,
const LookupResult &R);
void CheckShadow(Scope *S, VarDecl *D);
/// Warn if 'E', which is an expression that is about to be modified, refers
/// to a shadowing declaration.
void CheckShadowingDeclModification(Expr *E, SourceLocation Loc);
void DiagnoseShadowingLambdaDecls(const sema::LambdaScopeInfo *LSI);
/// Map of current shadowing declarations to shadowed declarations. Warn if
/// it looks like the user is trying to modify the shadowing declaration.
llvm::DenseMap<const NamedDecl *, const NamedDecl *> ShadowingDecls;
void CheckCastAlign(Expr *Op, QualType T, SourceRange TRange);
void handleTagNumbering(const TagDecl *Tag, Scope *TagScope);
void setTagNameForLinkagePurposes(TagDecl *TagFromDeclSpec,
TypedefNameDecl *NewTD);
void CheckTypedefForVariablyModifiedType(Scope *S, TypedefNameDecl *D);
NamedDecl* ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC,
TypeSourceInfo *TInfo,
LookupResult &Previous);
NamedDecl* ActOnTypedefNameDecl(Scope* S, DeclContext* DC, TypedefNameDecl *D,
LookupResult &Previous, bool &Redeclaration);
NamedDecl *ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
TypeSourceInfo *TInfo,
LookupResult &Previous,
MultiTemplateParamsArg TemplateParamLists,
bool &AddToScope,
ArrayRef<BindingDecl *> Bindings = None);
NamedDecl *
ActOnDecompositionDeclarator(Scope *S, Declarator &D,
MultiTemplateParamsArg TemplateParamLists);
// Returns true if the variable declaration is a redeclaration
bool CheckVariableDeclaration(VarDecl *NewVD, LookupResult &Previous);
void CheckVariableDeclarationType(VarDecl *NewVD);
bool DeduceVariableDeclarationType(VarDecl *VDecl, bool DirectInit,
Expr *Init);
void CheckCompleteVariableDeclaration(VarDecl *VD);
void CheckCompleteDecompositionDeclaration(DecompositionDecl *DD);
void MaybeSuggestAddingStaticToDecl(const FunctionDecl *D);
NamedDecl* ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC,
TypeSourceInfo *TInfo,
LookupResult &Previous,
MultiTemplateParamsArg TemplateParamLists,
bool &AddToScope);
bool AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD);
enum class CheckConstexprKind {
/// Diagnose issues that are non-constant or that are extensions.
/// Identify whether this function satisfies the formal rules for constexpr
/// functions in the current lanugage mode (with no extensions).
bool CheckConstexprFunctionDefinition(const FunctionDecl *FD,
CheckConstexprKind Kind);
void DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD);
void FindHiddenVirtualMethods(CXXMethodDecl *MD,
SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods);
void NoteHiddenVirtualMethods(CXXMethodDecl *MD,
SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods);
// Returns true if the function declaration is a redeclaration
bool CheckFunctionDeclaration(Scope *S,
FunctionDecl *NewFD, LookupResult &Previous,
bool IsMemberSpecialization);
bool shouldLinkDependentDeclWithPrevious(Decl *D, Decl *OldDecl);
bool canFullyTypeCheckRedeclaration(ValueDecl *NewD, ValueDecl *OldD,
QualType NewT, QualType OldT);
void CheckMain(FunctionDecl *FD, const DeclSpec &D);
void CheckMSVCRTEntryPoint(FunctionDecl *FD);
Attr *getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
bool IsDefinition);
void CheckFunctionOrTemplateParamDeclarator(Scope *S, Declarator &D);
Decl *ActOnParamDeclarator(Scope *S, Declarator &D);
ParmVarDecl *BuildParmVarDeclForTypedef(DeclContext *DC,
SourceLocation Loc,
QualType T);
ParmVarDecl *CheckParameter(DeclContext *DC, SourceLocation StartLoc,
SourceLocation NameLoc, IdentifierInfo *Name,
QualType T, TypeSourceInfo *TSInfo,
StorageClass SC);
void ActOnParamDefaultArgument(Decl *param,
SourceLocation EqualLoc,
Expr *defarg);
void ActOnParamUnparsedDefaultArgument(Decl *param,
SourceLocation EqualLoc,
SourceLocation ArgLoc);
void ActOnParamDefaultArgumentError(Decl *param, SourceLocation EqualLoc);
bool SetParamDefaultArgument(ParmVarDecl *Param, Expr *DefaultArg,
SourceLocation EqualLoc);
// Contexts where using non-trivial C union types can be disallowed. This is
// passed to err_non_trivial_c_union_in_invalid_context.
enum NonTrivialCUnionContext {
// Function parameter.
// Function return.
// Default-initialized object.
// Variable with automatic storage duration.
// Initializer expression that might copy from another object.
// Assignment.
// Compound literal.
// Block capture.
// lvalue-to-rvalue conversion of volatile type.
/// Emit diagnostics if the initializer or any of its explicit or
/// implicitly-generated subexpressions require copying or
/// default-initializing a type that is or contains a C union type that is
/// non-trivial to copy or default-initialize.
void checkNonTrivialCUnionInInitializer(const Expr *Init, SourceLocation Loc);
// These flags are passed to checkNonTrivialCUnion.
enum NonTrivialCUnionKind {
NTCUK_Init = 0x1,
NTCUK_Destruct = 0x2,
NTCUK_Copy = 0x4,
/// Emit diagnostics if a non-trivial C union type or a struct that contains
/// a non-trivial C union is used in an invalid context.
void checkNonTrivialCUnion(QualType QT, SourceLocation Loc,
NonTrivialCUnionContext UseContext,
unsigned NonTrivialKind);
void AddInitializerToDecl(Decl *dcl, Expr *init, bool DirectInit);
void ActOnUninitializedDecl(Decl *dcl);
void ActOnInitializerError(Decl *Dcl);
void ActOnPureSpecifier(Decl *D, SourceLocation PureSpecLoc);
void ActOnCXXForRangeDecl(Decl *D);
StmtResult ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc,
IdentifierInfo *Ident,
ParsedAttributes &Attrs,
SourceLocation AttrEnd);
void SetDeclDeleted(Decl *dcl, SourceLocation DelLoc);
void SetDeclDefaulted(Decl *dcl, SourceLocation DefaultLoc);
void CheckStaticLocalForDllExport(VarDecl *VD);
void FinalizeDeclaration(Decl *D);
DeclGroupPtrTy FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS,
ArrayRef<Decl *> Group);
DeclGroupPtrTy BuildDeclaratorGroup(MutableArrayRef<Decl *> Group);
/// Should be called on all declarations that might have attached
/// documentation comments.
void ActOnDocumentableDecl(Decl *D);
void ActOnDocumentableDecls(ArrayRef<Decl *> Group);
void ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D,
SourceLocation LocAfterDecls);
void CheckForFunctionRedefinition(
FunctionDecl *FD, const FunctionDecl *EffectiveDefinition = nullptr,
SkipBodyInfo *SkipBody = nullptr);
Decl *ActOnStartOfFunctionDef(Scope *S, Declarator &D,
MultiTemplateParamsArg TemplateParamLists,
SkipBodyInfo *SkipBody = nullptr);
Decl *ActOnStartOfFunctionDef(Scope *S, Decl *D,
SkipBodyInfo *SkipBody = nullptr);
void ActOnStartTrailingRequiresClause(Scope *S, Declarator &D);
ExprResult ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr);
void ActOnStartOfObjCMethodDef(Scope *S, Decl *D);
bool isObjCMethodDecl(Decl *D) {
return D && isa<ObjCMethodDecl>(D);
/// Determine whether we can delay parsing the body of a function or
/// function template until it is used, assuming we don't care about emitting
/// code for that function.
/// This will be \c false if we may need the body of the function in the
/// middle of parsing an expression (where it's impractical to switch to
/// parsing a different function), for instance, if it's constexpr in C++11
/// or has an 'auto' return type in C++14. These cases are essentially bugs.
bool canDelayFunctionBody(const Declarator &D);
/// Determine whether we can skip parsing the body of a function
/// definition, assuming we don't care about analyzing its body or emitting
/// code for that function.
/// This will be \c false only if we may need the body of the function in
/// order to parse the rest of the program (for instance, if it is
/// \c constexpr in C++11 or has an 'auto' return type in C++14).
bool canSkipFunctionBody(Decl *D);
void computeNRVO(Stmt *Body, sema::FunctionScopeInfo *Scope);
Decl *ActOnFinishFunctionBody(Decl *Decl, Stmt *Body);
Decl *ActOnFinishFunctionBody(Decl *Decl, Stmt *Body, bool IsInstantiation);
Decl *ActOnSkippedFunctionBody(Decl *Decl);
void ActOnFinishInlineFunctionDef(FunctionDecl *D);
/// ActOnFinishDelayedAttribute - Invoked when we have finished parsing an
/// attribute for which parsing is delayed.
void ActOnFinishDelayedAttribute(Scope *S, Decl *D, ParsedAttributes &Attrs);
/// Diagnose any unused parameters in the given sequence of
/// ParmVarDecl pointers.
void DiagnoseUnusedParameters(ArrayRef<ParmVarDecl *> Parameters);
/// Diagnose whether the size of parameters or return value of a
/// function or obj-c method definition is pass-by-value and larger than a
/// specified threshold.
DiagnoseSizeOfParametersAndReturnValue(ArrayRef<ParmVarDecl *> Parameters,
QualType ReturnTy, NamedDecl *D);
void DiagnoseInvalidJumps(Stmt *Body);
Decl *ActOnFileScopeAsmDecl(Expr *expr,
SourceLocation AsmLoc,
SourceLocation RParenLoc);
/// Handle a C++11 empty-declaration and attribute-declaration.
Decl *ActOnEmptyDeclaration(Scope *S, const ParsedAttributesView &AttrList,
SourceLocation SemiLoc);
enum class ModuleDeclKind {
Interface, ///< 'export module X;'
Implementation, ///< 'module X;'
/// The parser has processed a module-declaration that begins the definition
/// of a module interface or implementation.
DeclGroupPtrTy ActOnModuleDecl(SourceLocation StartLoc,
SourceLocation ModuleLoc, ModuleDeclKind MDK,
ModuleIdPath Path, bool IsFirstDecl);
/// The parser has processed a global-module-fragment declaration that begins
/// the definition of the global module fragment of the current module unit.
/// \param ModuleLoc The location of the 'module' keyword.
DeclGroupPtrTy ActOnGlobalModuleFragmentDecl(SourceLocation ModuleLoc);
/// The parser has processed a private-module-fragment declaration that begins
/// the definition of the private module fragment of the current module unit.
/// \param ModuleLoc The location of the 'module' keyword.
/// \param PrivateLoc The location of the 'private' keyword.
DeclGroupPtrTy ActOnPrivateModuleFragmentDecl(SourceLocation ModuleLoc,
SourceLocation PrivateLoc);
/// The parser has processed a module import declaration.
/// \param StartLoc The location of the first token in the declaration. This
/// could be the location of an '@', 'export', or 'import'.
/// \param ExportLoc The location of the 'export' keyword, if any.
/// \param ImportLoc The location of the 'import' keyword.
/// \param Path The module access path.
DeclResult ActOnModuleImport(SourceLocation StartLoc,
SourceLocation ExportLoc,
SourceLocation ImportLoc, ModuleIdPath Path);
DeclResult ActOnModuleImport(SourceLocation StartLoc,
SourceLocation ExportLoc,
SourceLocation ImportLoc, Module *M,
ModuleIdPath Path = {});
/// The parser has processed a module import translated from a
/// #include or similar preprocessing directive.
void ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod);
void BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod);
/// The parsed has entered a submodule.
void ActOnModuleBegin(SourceLocation DirectiveLoc, Module *Mod);
/// The parser has left a submodule.
void ActOnModuleEnd(SourceLocation DirectiveLoc, Module *Mod);
/// Create an implicit import of the given module at the given
/// source location, for error recovery, if possible.
/// This routine is typically used when an entity found by name lookup
/// is actually hidden within a module that we know about but the user
/// has forgotten to import.
void createImplicitModuleImportForErrorRecovery(SourceLocation Loc,
Module *Mod);
/// Kinds of missing import. Note, the values of these enumerators correspond
/// to %select values in diagnostics.
enum class MissingImportKind {
/// Diagnose that the specified declaration needs to be visible but
/// isn't, and suggest a module import that would resolve the problem.
void diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl,
MissingImportKind MIK, bool Recover = true);
void diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl,
SourceLocation DeclLoc, ArrayRef<Module *> Modules,
MissingImportKind MIK, bool Recover);
Decl *ActOnStartExportDecl(Scope *S, SourceLocation ExportLoc,
SourceLocation LBraceLoc);
Decl *ActOnFinishExportDecl(Scope *S, Decl *ExportDecl,
SourceLocation RBraceLoc);
/// We've found a use of a templated declaration that would trigger an
/// implicit instantiation. Check that any relevant explicit specializations
/// and partial specializations are visible, and diagnose if not.
void checkSpecializationVisibility(SourceLocation Loc, NamedDecl *Spec);
/// We've found a use of a template specialization that would select a
/// partial specialization. Check that the partial specialization is visible,
/// and diagnose if not.
void checkPartialSpecializationVisibility(SourceLocation Loc,
NamedDecl *Spec);
/// Retrieve a suitable printing policy for diagnostics.
PrintingPolicy getPrintingPolicy() const {
return getPrintingPolicy(Context, PP);
/// Retrieve a suitable printing policy for diagnostics.
static PrintingPolicy getPrintingPolicy(const ASTContext &Ctx,
const Preprocessor &PP);
/// Scope actions.
void ActOnPopScope(SourceLocation Loc, Scope *S);
void ActOnTranslationUnitScope(Scope *S);
Decl *ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
RecordDecl *&AnonRecord);
Decl *ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
MultiTemplateParamsArg TemplateParams,
bool IsExplicitInstantiation,
RecordDecl *&AnonRecord);
Decl *BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
AccessSpecifier AS,
RecordDecl *Record,
const PrintingPolicy &Policy);
Decl *BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS,
RecordDecl *Record);
/// Common ways to introduce type names without a tag for use in diagnostics.
/// Keep in sync with err_tag_reference_non_tag.
enum NonTagKind {
/// Given a non-tag type declaration, returns an enum useful for indicating
/// what kind of non-tag type this is.
NonTagKind getNonTagTypeDeclKind(const Decl *D, TagTypeKind TTK);
bool isAcceptableTagRedeclaration(const TagDecl *Previous,
TagTypeKind NewTag, bool isDefinition,
SourceLocation NewTagLoc,
const IdentifierInfo *Name);
enum TagUseKind {
TUK_Reference, // Reference to a tag: 'struct foo *X;'
TUK_Declaration, // Fwd decl of a tag: 'struct foo;'
TUK_Definition, // Definition of a tag: 'struct foo { int X; } Y;'
TUK_Friend // Friend declaration: 'friend struct foo;'
Decl *ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
SourceLocation KWLoc, CXXScopeSpec &SS, IdentifierInfo *Name,
SourceLocation NameLoc, const ParsedAttributesView &Attr,
AccessSpecifier AS, SourceLocation ModulePrivateLoc,
MultiTemplateParamsArg TemplateParameterLists, bool &OwnedDecl,
bool &IsDependent, SourceLocation ScopedEnumKWLoc,
bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
bool IsTypeSpecifier, bool IsTemplateParamOrArg,
SkipBodyInfo *SkipBody = nullptr);
Decl *ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
unsigned TagSpec, SourceLocation TagLoc,
CXXScopeSpec &SS, IdentifierInfo *Name,
SourceLocation NameLoc,
const ParsedAttributesView &Attr,
MultiTemplateParamsArg TempParamLists);
TypeResult ActOnDependentTag(Scope *S,
unsigned TagSpec,
TagUseKind TUK,
const CXXScopeSpec &SS,
IdentifierInfo *Name,
SourceLocation TagLoc,
SourceLocation NameLoc);
void ActOnDefs(Scope *S, Decl *TagD, SourceLocation DeclStart,
IdentifierInfo *ClassName,
SmallVectorImpl<Decl *> &Decls);
Decl *ActOnField(Scope *S, Decl *TagD, SourceLocation DeclStart,
Declarator &D, Expr *BitfieldWidth);
FieldDecl *HandleField(Scope *S, RecordDecl *TagD, SourceLocation DeclStart,
Declarator &D, Expr *BitfieldWidth,
InClassInitStyle InitStyle,
AccessSpecifier AS);
MSPropertyDecl *HandleMSProperty(Scope *S, RecordDecl *TagD,
SourceLocation DeclStart, Declarator &D,
Expr *BitfieldWidth,
InClassInitStyle InitStyle,
AccessSpecifier AS,
const ParsedAttr &MSPropertyAttr);
FieldDecl *CheckFieldDecl(DeclarationName Name, QualType T,
TypeSourceInfo *TInfo,
RecordDecl *Record, SourceLocation Loc,
bool Mutable, Expr *BitfieldWidth,
InClassInitStyle InitStyle,
SourceLocation TSSL,
AccessSpecifier AS, NamedDecl *PrevDecl,
Declarator *D = nullptr);
bool CheckNontrivialField(FieldDecl *FD);
void DiagnoseNontrivial(const CXXRecordDecl *Record, CXXSpecialMember CSM);
enum TrivialABIHandling {
/// The triviality of a method unaffected by "trivial_abi".
/// The triviality of a method affected by "trivial_abi".
bool SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM,
TrivialABIHandling TAH = TAH_IgnoreTrivialABI,
bool Diagnose = false);
/// For a defaulted function, the kind of defaulted function that it is.
class DefaultedFunctionKind {
CXXSpecialMember SpecialMember : 8;
DefaultedComparisonKind Comparison : 8;
: SpecialMember(CXXInvalid), Comparison(DefaultedComparisonKind::None) {
DefaultedFunctionKind(CXXSpecialMember CSM)
: SpecialMember(CSM), Comparison(DefaultedComparisonKind::None) {}
DefaultedFunctionKind(DefaultedComparisonKind Comp)
: SpecialMember(CXXInvalid), Comparison(Comp) {}
bool isSpecialMember() const { return SpecialMember != CXXInvalid; }
bool isComparison() const {
return Comparison != DefaultedComparisonKind::None;
explicit operator bool() const {
return isSpecialMember() || isComparison();
CXXSpecialMember asSpecialMember() const { return SpecialMember; }