mirrors/llvm-project
0
0
Fork 0
mirror of https://github.com/llvm/llvm-project.git synced 2025-05-02 19:26:05 +00:00
Code Issues Projects Releases Wiki Activity
llvm-project/clang/lib/Sema/Sema.cpp
Douglas Gregor 840bd6cce5 Implement basic support for template instantiation of pack expansions 
whose patterns are template arguments. We can now instantiate, e.g.,

  typedef tuple<pair<OuterTypes, InnerTypes>...> type;

where OuterTypes and InnerTypes are template type parameter packs.

There is a horrible inefficiency in
TemplateArgumentLoc::getPackExpansionPattern(), where we need to
create copies of TypeLoc data because our interfaces traffic in
TypeSourceInfo pointers where they should traffic in TypeLocs
instead. I've isolated in efficiency in this one routine; once we
refactor our interfaces to traffic in TypeLocs, we can eliminate it.

llvm-svn: 122278
2010-12-20 22:05:00 +00:00

607 lines
22 KiB
C++
Raw Blame History

//===--- Sema.cpp - AST Builder and Semantic Analysis Implementation ------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the actions class which performs semantic analysis and
// builds an AST out of a parse stream.
//
//===----------------------------------------------------------------------===//
#include "clang/Sema/SemaInternal.h"
#include "clang/Sema/DelayedDiagnostic.h"
#include "TargetAttributesSema.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/APFloat.h"
#include "clang/Sema/CXXFieldCollector.h"
#include "clang/Sema/TemplateDeduction.h"
#include "clang/Sema/ExternalSemaSource.h"
#include "clang/Sema/ObjCMethodList.h"
#include "clang/Sema/PrettyDeclStackTrace.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/SemaConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTDiagnostic.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Expr.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Basic/PartialDiagnostic.h"
#include "clang/Basic/TargetInfo.h"
using namespace clang;
using namespace sema;
FunctionScopeInfo::~FunctionScopeInfo() { }
void FunctionScopeInfo::Clear() {
HasBranchProtectedScope = false;
HasBranchIntoScope = false;
HasIndirectGoto = false;
LabelMap.clear();
SwitchStack.clear();
Returns.clear();
ErrorTrap.reset();
}
BlockScopeInfo::~BlockScopeInfo() { }
void Sema::ActOnTranslationUnitScope(Scope *S) {
TUScope = S;
PushDeclContext(S, Context.getTranslationUnitDecl());
VAListTagName = PP.getIdentifierInfo("__va_list_tag");
if (!Context.isInt128Installed() && // May be set by ASTReader.
PP.getTargetInfo().getPointerWidth(0) >= 64) {
TypeSourceInfo *TInfo;
// Install [u]int128_t for 64-bit targets.
TInfo = Context.getTrivialTypeSourceInfo(Context.Int128Ty);
PushOnScopeChains(TypedefDecl::Create(Context, CurContext,
SourceLocation(),
&Context.Idents.get("__int128_t"),
TInfo), TUScope);
TInfo = Context.getTrivialTypeSourceInfo(Context.UnsignedInt128Ty);
PushOnScopeChains(TypedefDecl::Create(Context, CurContext,
SourceLocation(),
&Context.Idents.get("__uint128_t"),
TInfo), TUScope);
Context.setInt128Installed();
}
if (!PP.getLangOptions().ObjC1) return;
// Built-in ObjC types may already be set by ASTReader (hence isNull checks).
if (Context.getObjCSelType().isNull()) {
// Create the built-in typedef for 'SEL'.
QualType SelT = Context.getPointerType(Context.ObjCBuiltinSelTy);
TypeSourceInfo *SelInfo = Context.getTrivialTypeSourceInfo(SelT);
TypedefDecl *SelTypedef
= TypedefDecl::Create(Context, CurContext, SourceLocation(),
&Context.Idents.get("SEL"), SelInfo);
PushOnScopeChains(SelTypedef, TUScope);
Context.setObjCSelType(Context.getTypeDeclType(SelTypedef));
Context.ObjCSelRedefinitionType = Context.getObjCSelType();
}
// Synthesize "@class Protocol;
if (Context.getObjCProtoType().isNull()) {
ObjCInterfaceDecl *ProtocolDecl =
ObjCInterfaceDecl::Create(Context, CurContext, SourceLocation(),
&Context.Idents.get("Protocol"),
SourceLocation(), true);
Context.setObjCProtoType(Context.getObjCInterfaceType(ProtocolDecl));
PushOnScopeChains(ProtocolDecl, TUScope, false);
}
// Create the built-in typedef for 'id'.
if (Context.getObjCIdType().isNull()) {
QualType T = Context.getObjCObjectType(Context.ObjCBuiltinIdTy, 0, 0);
T = Context.getObjCObjectPointerType(T);
TypeSourceInfo *IdInfo = Context.getTrivialTypeSourceInfo(T);
TypedefDecl *IdTypedef
= TypedefDecl::Create(Context, CurContext, SourceLocation(),
&Context.Idents.get("id"), IdInfo);
PushOnScopeChains(IdTypedef, TUScope);
Context.setObjCIdType(Context.getTypeDeclType(IdTypedef));
Context.ObjCIdRedefinitionType = Context.getObjCIdType();
}
// Create the built-in typedef for 'Class'.
if (Context.getObjCClassType().isNull()) {
QualType T = Context.getObjCObjectType(Context.ObjCBuiltinClassTy, 0, 0);
T = Context.getObjCObjectPointerType(T);
TypeSourceInfo *ClassInfo = Context.getTrivialTypeSourceInfo(T);
TypedefDecl *ClassTypedef
= TypedefDecl::Create(Context, CurContext, SourceLocation(),
&Context.Idents.get("Class"), ClassInfo);
PushOnScopeChains(ClassTypedef, TUScope);
Context.setObjCClassType(Context.getTypeDeclType(ClassTypedef));
Context.ObjCClassRedefinitionType = Context.getObjCClassType();
}
}
Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
bool CompleteTranslationUnit,
CodeCompleteConsumer *CodeCompleter)
: TheTargetAttributesSema(0),
LangOpts(pp.getLangOptions()), PP(pp), Context(ctxt), Consumer(consumer),
Diags(PP.getDiagnostics()), SourceMgr(PP.getSourceManager()),
ExternalSource(0), CodeCompleter(CodeCompleter), CurContext(0),
PackContext(0), VisContext(0), ParsingDeclDepth(0),
IdResolver(pp.getLangOptions()), CXXTypeInfoDecl(0), MSVCGuidDecl(0),
GlobalNewDeleteDeclared(false),
CompleteTranslationUnit(CompleteTranslationUnit),
NumSFINAEErrors(0), SuppressAccessChecking(false),
NonInstantiationEntries(0), ArgumentPackSubstitutionIndex(-1),
CurrentInstantiationScope(0), TyposCorrected(0),
AnalysisWarnings(*this)
{
TUScope = 0;
if (getLangOptions().CPlusPlus)
FieldCollector.reset(new CXXFieldCollector());
// Tell diagnostics how to render things from the AST library.
PP.getDiagnostics().SetArgToStringFn(&FormatASTNodeDiagnosticArgument,
&Context);
ExprEvalContexts.push_back(
ExpressionEvaluationContextRecord(PotentiallyEvaluated, 0));
FunctionScopes.push_back(new FunctionScopeInfo(Diags));
}
void Sema::Initialize() {
// Tell the AST consumer about this Sema object.
Consumer.Initialize(Context);
// FIXME: Isn't this redundant with the initialization above?
if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer))
SC->InitializeSema(*this);
// Tell the external Sema source about this Sema object.
if (ExternalSemaSource *ExternalSema
= dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource()))
ExternalSema->InitializeSema(*this);
}
Sema::~Sema() {
if (PackContext) FreePackedContext();
if (VisContext) FreeVisContext();
delete TheTargetAttributesSema;
// Kill all the active scopes.
for (unsigned I = 1, E = FunctionScopes.size(); I != E; ++I)
delete FunctionScopes[I];
if (FunctionScopes.size() == 1)
delete FunctionScopes[0];
// Tell the SemaConsumer to forget about us; we're going out of scope.
if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer))
SC->ForgetSema();
// Detach from the external Sema source.
if (ExternalSemaSource *ExternalSema
= dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource()))
ExternalSema->ForgetSema();
}
/// 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.
void Sema::ImpCastExprToType(Expr *&Expr, QualType Ty,
CastKind Kind, ExprValueKind VK,
const CXXCastPath *BasePath) {
QualType ExprTy = Context.getCanonicalType(Expr->getType());
QualType TypeTy = Context.getCanonicalType(Ty);
if (ExprTy == TypeTy)
return;
if (Expr->getType()->isPointerType() && Ty->isPointerType()) {
QualType ExprBaseType = cast<PointerType>(ExprTy)->getPointeeType();
QualType BaseType = cast<PointerType>(TypeTy)->getPointeeType();
if (ExprBaseType.getAddressSpace() != BaseType.getAddressSpace()) {
Diag(Expr->getExprLoc(), diag::err_implicit_pointer_address_space_cast)
<< Expr->getSourceRange();
}
}
// If this is a derived-to-base cast to a through a virtual base, we
// need a vtable.
if (Kind == CK_DerivedToBase &&
BasePathInvolvesVirtualBase(*BasePath)) {
QualType T = Expr->getType();
if (const PointerType *Pointer = T->getAs<PointerType>())
T = Pointer->getPointeeType();
if (const RecordType *RecordTy = T->getAs<RecordType>())
MarkVTableUsed(Expr->getLocStart(),
cast<CXXRecordDecl>(RecordTy->getDecl()));
}
if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(Expr)) {
if (ImpCast->getCastKind() == Kind && (!BasePath || BasePath->empty())) {
ImpCast->setType(Ty);
ImpCast->setValueKind(VK);
return;
}
}
Expr = ImplicitCastExpr::Create(Context, Ty, Kind, Expr, BasePath, VK);
}
ExprValueKind Sema::CastCategory(Expr *E) {
Expr::Classification Classification = E->Classify(Context);
return Classification.isRValue() ? VK_RValue :
(Classification.isLValue() ? VK_LValue : VK_XValue);
}
/// \brief Used to prune the decls of Sema's UnusedFileScopedDecls vector.
static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) {
if (D->isUsed())
return true;
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
// 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->getMostRecentDeclaration();
if (DeclToCheck != FD)
return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
}
if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
// 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->getMostRecentDeclaration();
if (DeclToCheck != VD)
return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
}
return false;
}
/// 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() {
// At PCH writing, implicit instantiations and VTable handling info are
// stored and performed when the PCH is included.
if (CompleteTranslationUnit) {
// If any dynamic classes have their key function defined within
// this translation unit, then those vtables are considered "used" and must
// be emitted.
for (unsigned I = 0, N = DynamicClasses.size(); I != N; ++I) {
if (const CXXMethodDecl *KeyFunction
= Context.getKeyFunction(DynamicClasses[I])) {
const FunctionDecl *Definition = 0;
if (KeyFunction->hasBody(Definition))
MarkVTableUsed(Definition->getLocation(), DynamicClasses[I], true);
}
}
// If DefinedUsedVTables ends up marking any virtual member functions it
// might lead to more pending template instantiations, which we then need
// to instantiate.
DefineUsedVTables();
// 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 should not be found. Although this is
// common behavior for C++ compilers, it is technically wrong. In the
// future, we either need to be able to filter the results of name lookup
// or we need to perform template instantiations earlier.
PerformPendingInstantiations();
}
// Remove file scoped decls that turned out to be used.
UnusedFileScopedDecls.erase(std::remove_if(UnusedFileScopedDecls.begin(),
UnusedFileScopedDecls.end(),
std::bind1st(std::ptr_fun(ShouldRemoveFromUnused),
this)),
UnusedFileScopedDecls.end());
if (!CompleteTranslationUnit) {
TUScope = 0;
return;
}
// Check for #pragma weak identifiers that were never declared
// FIXME: This will cause diagnostics to be emitted in a non-determinstic
// order! Iterating over a densemap like this is bad.
for (llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator
I = WeakUndeclaredIdentifiers.begin(),
E = WeakUndeclaredIdentifiers.end(); I != E; ++I) {
if (I->second.getUsed()) continue;
Diag(I->second.getLocation(), diag::warn_weak_identifier_undeclared)
<< I->first;
}
// 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 (unsigned i = 0, e = TentativeDefinitions.size(); i != e; ++i) {
VarDecl *VD = TentativeDefinitions[i]->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 == 0 || VD->isInvalidDecl() || !Seen.insert(VD))
continue;
if (const IncompleteArrayType *ArrayT
= Context.getAsIncompleteArrayType(VD->getType())) {
if (RequireCompleteType(VD->getLocation(),
ArrayT->getElementType(),
diag::err_tentative_def_incomplete_type_arr)) {
VD->setInvalidDecl();
continue;
}
// 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, ArrayType::Normal, 0);
VD->setType(T);
} else if (RequireCompleteType(VD->getLocation(), VD->getType(),
diag::err_tentative_def_incomplete_type))
VD->setInvalidDecl();
// Notify the consumer that we've completed a tentative definition.
if (!VD->isInvalidDecl())
Consumer.CompleteTentativeDefinition(VD);
}
// Output warning for unused file scoped decls.
for (llvm::SmallVectorImpl<const DeclaratorDecl*>::iterator
I = UnusedFileScopedDecls.begin(),
E = UnusedFileScopedDecls.end(); I != E; ++I) {
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
const FunctionDecl *DiagD;
if (!FD->hasBody(DiagD))
DiagD = FD;
Diag(DiagD->getLocation(),
isa<CXXMethodDecl>(DiagD) ? diag::warn_unused_member_function
: diag::warn_unused_function)
<< DiagD->getDeclName();
} else {
const VarDecl *DiagD = cast<VarDecl>(*I)->getDefinition();
if (!DiagD)
DiagD = cast<VarDecl>(*I);
Diag(DiagD->getLocation(), diag::warn_unused_variable)
<< DiagD->getDeclName();
}
}
TUScope = 0;
}
//===----------------------------------------------------------------------===//
// Helper functions.
//===----------------------------------------------------------------------===//
DeclContext *Sema::getFunctionLevelDeclContext() {
DeclContext *DC = CurContext;
while (isa<BlockDecl>(DC) || isa<EnumDecl>(DC))
DC = DC->getParent();
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();
return dyn_cast<ObjCMethodDecl>(DC);
}
NamedDecl *Sema::getCurFunctionOrMethodDecl() {
DeclContext *DC = getFunctionLevelDeclContext();
if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC))
return cast<NamedDecl>(DC);
return 0;
}
Sema::SemaDiagnosticBuilder::~SemaDiagnosticBuilder() {
if (!isActive())
return;
if (TemplateDeductionInfo *Info = SemaRef.isSFINAEContext()) {
switch (DiagnosticIDs::getDiagnosticSFINAEResponse(getDiagID())) {
case DiagnosticIDs::SFINAE_Report:
// Fall through; we'll report the diagnostic below.
break;
case DiagnosticIDs::SFINAE_SubstitutionFailure:
// Count this failure so that we know that template argument deduction
// has failed.
++SemaRef.NumSFINAEErrors;
SemaRef.Diags.setLastDiagnosticIgnored();
SemaRef.Diags.Clear();
Clear();
return;
case DiagnosticIDs::SFINAE_Suppress:
// Make a copy of this suppressed diagnostic and store it with the
// template-deduction information;
FlushCounts();
DiagnosticInfo DiagInfo(&SemaRef.Diags);
Info->addSuppressedDiagnostic(DiagInfo.getLocation(),
PartialDiagnostic(DiagInfo,
SemaRef.Context.getDiagAllocator()));
// Suppress this diagnostic.
SemaRef.Diags.setLastDiagnosticIgnored();
SemaRef.Diags.Clear();
Clear();
return;
}
}
// Emit the diagnostic.
if (!this->Emit())
return;
// 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) &&
!SemaRef.ActiveTemplateInstantiations.empty() &&
SemaRef.ActiveTemplateInstantiations.back()
!= SemaRef.LastTemplateInstantiationErrorContext) {
SemaRef.PrintInstantiationStack();
SemaRef.LastTemplateInstantiationErrorContext
= SemaRef.ActiveTemplateInstantiations.back();
}
}
Sema::SemaDiagnosticBuilder Sema::Diag(SourceLocation Loc, unsigned DiagID) {
DiagnosticBuilder DB = Diags.Report(Loc, DiagID);
return SemaDiagnosticBuilder(DB, *this, DiagID);
}
Sema::SemaDiagnosticBuilder
Sema::Diag(SourceLocation Loc, const PartialDiagnostic& PD) {
SemaDiagnosticBuilder Builder(Diag(Loc, PD.getDiagID()));
PD.Emit(Builder);
return Builder;
}
/// \brief 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 0;
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 = static_cast<DeclContext *> (S->getEntity()))
if (Ctx == Entity->getPrimaryContext())
return S;
}
return 0;
}
/// \brief Enter a new function scope
void Sema::PushFunctionScope() {
if (FunctionScopes.size() == 1) {
// Use the "top" function scope rather than having to allocate
// memory for a new scope.
FunctionScopes.back()->Clear();
FunctionScopes.push_back(FunctionScopes.back());
return;
}
FunctionScopes.push_back(new FunctionScopeInfo(getDiagnostics()));
}
void Sema::PushBlockScope(Scope *BlockScope, BlockDecl *Block) {
FunctionScopes.push_back(new BlockScopeInfo(getDiagnostics(),
BlockScope, Block));
}
void Sema::PopFunctionOrBlockScope() {
FunctionScopeInfo *Scope = FunctionScopes.pop_back_val();
assert(!FunctionScopes.empty() && "mismatched push/pop!");
if (FunctionScopes.back() != Scope)
delete Scope;
}
/// \brief Determine whether any errors occurred within this function/method/
/// block.
bool Sema::hasAnyErrorsInThisFunction() const {
return getCurFunction()->ErrorTrap.hasErrorOccurred();
}
BlockScopeInfo *Sema::getCurBlock() {
if (FunctionScopes.empty())
return 0;
return dyn_cast<BlockScopeInfo>(FunctionScopes.back());
}
// Pin this vtable to this file.
ExternalSemaSource::~ExternalSemaSource() {}
std::pair<ObjCMethodList, ObjCMethodList>
ExternalSemaSource::ReadMethodPool(Selector Sel) {
return std::pair<ObjCMethodList, ObjCMethodList>();
}
void PrettyDeclStackTraceEntry::print(llvm::raw_ostream &OS) const {
SourceLocation Loc = this->Loc;
if (!Loc.isValid() && TheDecl) Loc = TheDecl->getLocation();
if (Loc.isValid()) {
Loc.print(OS, S.getSourceManager());
OS << ": ";
}
OS << Message;
if (TheDecl && isa<NamedDecl>(TheDecl)) {
std::string Name = cast<NamedDecl>(TheDecl)->getNameAsString();
if (!Name.empty())
OS << " '" << Name << '\'';
}
OS << '\n';
}
Reference in New Issue View Git Blame Copy Permalink