//===--- 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 "Sema.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Expr.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Basic/TargetInfo.h"
using namespace clang;
/// ConvertQualTypeToStringFn - This function is used to pretty print the
/// specified QualType as a string in diagnostics.
static void ConvertArgToStringFn(Diagnostic::ArgumentKind Kind, intptr_t Val,
const char *Modifier, unsigned ModLen,
const char *Argument, unsigned ArgLen,
llvm::SmallVectorImpl<char> &Output,
void *Cookie) {
ASTContext &Context = *static_cast<ASTContext*>(Cookie);
std::string S;
if (Kind == Diagnostic::ak_qualtype) {
assert(ModLen == 0 && ArgLen == 0 &&
"Invalid modifier for QualType argument");
QualType Ty(QualType::getFromOpaquePtr(reinterpret_cast<void*>(Val)));
// FIXME: Playing with std::string is really slow.
S = Ty.getAsString(Context.PrintingPolicy);
// If this is a sugared type (like a typedef, typeof, etc), then unwrap one
// level of the sugar so that the type is more obvious to the user.
QualType DesugaredTy = Ty->getDesugaredType(true);
DesugaredTy.setCVRQualifiers(DesugaredTy.getCVRQualifiers() |
Ty.getCVRQualifiers());
if (Ty != DesugaredTy &&
// If the desugared type is a vector type, we don't want to expand it,
// it will turn into an attribute mess. People want their "vec4".
!isa<VectorType>(DesugaredTy) &&
// Don't desugar magic Objective-C types.
Ty.getUnqualifiedType() != Context.getObjCIdType() &&
Ty.getUnqualifiedType() != Context.getObjCSelType() &&
Ty.getUnqualifiedType() != Context.getObjCProtoType() &&
Ty.getUnqualifiedType() != Context.getObjCClassType() &&
// Not va_list.
Ty.getUnqualifiedType() != Context.getBuiltinVaListType()) {
S = "'"+S+"' (aka '";
S += DesugaredTy.getAsString(Context.PrintingPolicy);
S += "')";
Output.append(S.begin(), S.end());
return;
}
} else if (Kind == Diagnostic::ak_declarationname) {
DeclarationName N = DeclarationName::getFromOpaqueInteger(Val);
S = N.getAsString();
if (ModLen == 9 && !memcmp(Modifier, "objcclass", 9) && ArgLen == 0)
S = '+' + S;
else if (ModLen == 12 && !memcmp(Modifier, "objcinstance", 12) && ArgLen==0)
S = '-' + S;
else
assert(ModLen == 0 && ArgLen == 0 &&
"Invalid modifier for DeclarationName argument");
} else {
assert(Kind == Diagnostic::ak_nameddecl);
if (ModLen == 1 && Modifier[0] == 'q' && ArgLen == 0)
S = reinterpret_cast<NamedDecl*>(Val)->getQualifiedNameAsString();
else {
assert(ModLen == 0 && ArgLen == 0 &&
"Invalid modifier for NamedDecl* argument");
S = reinterpret_cast<NamedDecl*>(Val)->getNameAsString();
}
}
Output.push_back('\'');
Output.append(S.begin(), S.end());
Output.push_back('\'');
}
static inline RecordDecl *CreateStructDecl(ASTContext &C, const char *Name) {
if (C.getLangOptions().CPlusPlus)
return CXXRecordDecl::Create(C, TagDecl::TK_struct,
C.getTranslationUnitDecl(),
SourceLocation(), &C.Idents.get(Name));
return RecordDecl::Create(C, TagDecl::TK_struct,
C.getTranslationUnitDecl(),
SourceLocation(), &C.Idents.get(Name));
}
void Sema::ActOnTranslationUnitScope(SourceLocation Loc, Scope *S) {
TUScope = S;
PushDeclContext(S, Context.getTranslationUnitDecl());
if (PP.getTargetInfo().getPointerWidth(0) >= 64) {
// Install [u]int128_t for 64-bit targets.
PushOnScopeChains(TypedefDecl::Create(Context, CurContext,
SourceLocation(),
&Context.Idents.get("__int128_t"),
Context.Int128Ty), TUScope);
PushOnScopeChains(TypedefDecl::Create(Context, CurContext,
SourceLocation(),
&Context.Idents.get("__uint128_t"),
Context.UnsignedInt128Ty), TUScope);
}
if (!PP.getLangOptions().ObjC1) return;
// Built-in ObjC types may already be set by PCHReader (hence isNull checks).
if (Context.getObjCSelType().isNull()) {
// Synthesize "typedef struct objc_selector *SEL;"
RecordDecl *SelTag = CreateStructDecl(Context, "objc_selector");
PushOnScopeChains(SelTag, TUScope);
QualType SelT = Context.getPointerType(Context.getTagDeclType(SelTag));
TypedefDecl *SelTypedef = TypedefDecl::Create(Context, CurContext,
SourceLocation(),
&Context.Idents.get("SEL"),
SelT);
PushOnScopeChains(SelTypedef, TUScope);
Context.setObjCSelType(Context.getTypeDeclType(SelTypedef));
}
if (Context.getObjCClassType().isNull()) {
RecordDecl *ClassTag = CreateStructDecl(Context, "objc_class");
QualType ClassT = Context.getPointerType(Context.getTagDeclType(ClassTag));
TypedefDecl *ClassTypedef =
TypedefDecl::Create(Context, CurContext, SourceLocation(),
&Context.Idents.get("Class"), ClassT);
PushOnScopeChains(ClassTag, TUScope);
PushOnScopeChains(ClassTypedef, TUScope);
Context.setObjCClassType(Context.getTypeDeclType(ClassTypedef));
}
// 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);
}
// Synthesize "typedef struct objc_object { Class isa; } *id;"
if (Context.getObjCIdType().isNull()) {
RecordDecl *ObjectTag = CreateStructDecl(Context, "objc_object");
QualType ObjT = Context.getPointerType(Context.getTagDeclType(ObjectTag));
PushOnScopeChains(ObjectTag, TUScope);
TypedefDecl *IdTypedef = TypedefDecl::Create(Context, CurContext,
SourceLocation(),
&Context.Idents.get("id"),
ObjT);
PushOnScopeChains(IdTypedef, TUScope);
Context.setObjCIdType(Context.getTypeDeclType(IdTypedef));
}
}
Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
bool CompleteTranslationUnit)
: LangOpts(pp.getLangOptions()), PP(pp), Context(ctxt), Consumer(consumer),
Diags(PP.getDiagnostics()), SourceMgr(PP.getSourceManager()),
ExternalSource(0), CurContext(0), PreDeclaratorDC(0),
CurBlock(0), PackContext(0), IdResolver(pp.getLangOptions()),
GlobalNewDeleteDeclared(false), ExprEvalContext(PotentiallyEvaluated),
CompleteTranslationUnit(CompleteTranslationUnit),
NumSFINAEErrors(0), CurrentInstantiationScope(0) {
StdNamespace = 0;
TUScope = 0;
if (getLangOptions().CPlusPlus)
FieldCollector.reset(new CXXFieldCollector());
// Tell diagnostics how to render things from the AST library.
PP.getDiagnostics().SetArgToStringFn(ConvertArgToStringFn, &Context);
}
/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast.
/// If there is already an implicit cast, merge into the existing one.
/// If isLvalue, the result of the cast is an lvalue.
void Sema::ImpCastExprToType(Expr *&Expr, QualType Ty, bool isLvalue) {
QualType ExprTy = Context.getCanonicalType(Expr->getType());
QualType TypeTy = Context.getCanonicalType(Ty);
if (ExprTy == TypeTy)
return;
if (Expr->getType().getTypePtr()->isPointerType() &&
Ty.getTypePtr()->isPointerType()) {
QualType ExprBaseType =
cast<PointerType>(ExprTy.getUnqualifiedType())->getPointeeType();
QualType BaseType =
cast<PointerType>(TypeTy.getUnqualifiedType())->getPointeeType();
if (ExprBaseType.getAddressSpace() != BaseType.getAddressSpace()) {
Diag(Expr->getExprLoc(), diag::err_implicit_pointer_address_space_cast)
<< Expr->getSourceRange();
}
}
if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(Expr)) {
ImpCast->setType(Ty);
ImpCast->setLvalueCast(isLvalue);
} else
Expr = new (Context) ImplicitCastExpr(Ty, Expr, isLvalue);
}
void Sema::DeleteExpr(ExprTy *E) {
if (E) static_cast<Expr*>(E)->Destroy(Context);
}
void Sema::DeleteStmt(StmtTy *S) {
if (S) static_cast<Stmt*>(S)->Destroy(Context);
}
/// 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() {
// 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.
PerformPendingImplicitInstantiations();
if (!CompleteTranslationUnit)
return;
// 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.
for (llvm::DenseMap<DeclarationName, VarDecl *>::iterator
D = TentativeDefinitions.begin(),
DEnd = TentativeDefinitions.end();
D != DEnd; ++D) {
VarDecl *VD = D->second;
if (VD->isInvalidDecl() || !VD->isTentativeDefinition(Context))
continue;
if (const IncompleteArrayType *ArrayT
= Context.getAsIncompleteArrayType(VD->getType())) {
if (RequireCompleteType(VD->getLocation(),
ArrayT->getElementType(),
diag::err_tentative_def_incomplete_type_arr))
VD->setInvalidDecl();
else {
// 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);
}
}
//===----------------------------------------------------------------------===//
// Helper functions.
//===----------------------------------------------------------------------===//
/// 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 = CurContext;
while (isa<BlockDecl>(DC))
DC = DC->getParent();
return dyn_cast<FunctionDecl>(DC);
}
ObjCMethodDecl *Sema::getCurMethodDecl() {
DeclContext *DC = CurContext;
while (isa<BlockDecl>(DC))
DC = DC->getParent();
return dyn_cast<ObjCMethodDecl>(DC);
}
NamedDecl *Sema::getCurFunctionOrMethodDecl() {
DeclContext *DC = CurContext;
while (isa<BlockDecl>(DC))
DC = DC->getParent();
if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC))
return cast<NamedDecl>(DC);
return 0;
}
Sema::SemaDiagnosticBuilder::~SemaDiagnosticBuilder() {
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 (!SemaRef.Diags.isBuiltinNote(DiagID) &&
!SemaRef.ActiveTemplateInstantiations.empty() &&
SemaRef.ActiveTemplateInstantiations.back()
!= SemaRef.LastTemplateInstantiationErrorContext) {
SemaRef.PrintInstantiationStack();
SemaRef.LastTemplateInstantiationErrorContext
= SemaRef.ActiveTemplateInstantiations.back();
}
}