path: root/lib/Sema/Sema.cpp

//===--- 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 "llvm/ADT/DenseMap.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/PartialDiagnostic.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 aka just because we saw an elaborated type.
        (!isa<ElaboratedType>(Ty) ||
         cast<ElaboratedType>(Ty)->getUnderlyingType() != DesugaredTy) &&
      
        // Don't desugar magic Objective-C types.
        Ty.getUnqualifiedType() != Context.getObjCIdType() &&
        Ty.getUnqualifiedType() != Context.getObjCClassType() &&
        Ty.getUnqualifiedType() != Context.getObjCSelType() &&
        Ty.getUnqualifiedType() != Context.getObjCProtoType() &&
        
        // 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 if (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();
    }
  } else {
    llvm::raw_string_ostream OS(S);
    assert(Kind == Diagnostic::ak_nestednamespec);
    reinterpret_cast<NestedNameSpecifier*> (Val)->print(OS, 
                                                        Context.PrintingPolicy);
  }
  
  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));
  }

  // 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);
  }
  // Create the built-in typedef for 'id'.
  if (Context.getObjCIdType().isNull()) {
    TypedefDecl *IdTypedef = 
      TypedefDecl::Create( 
        Context, CurContext, SourceLocation(), &Context.Idents.get("id"),
        Context.getObjCObjectPointerType(Context.ObjCBuiltinIdTy)
      );
    PushOnScopeChains(IdTypedef, TUScope);
    Context.setObjCIdType(Context.getTypeDeclType(IdTypedef));
    Context.ObjCIdRedefinitionType = Context.getObjCIdType();
  }
  // Create the built-in typedef for 'Class'.
  if (Context.getObjCClassType().isNull()) {
    TypedefDecl *ClassTypedef = 
      TypedefDecl::Create( 
        Context, CurContext, SourceLocation(), &Context.Idents.get("Class"),
        Context.getObjCObjectPointerType(Context.ObjCBuiltinClassTy)
      );
    PushOnScopeChains(ClassTypedef, TUScope);
    Context.setObjCClassType(Context.getTypeDeclType(ClassTypedef));
    Context.ObjCClassRedefinitionType = Context.getObjCClassType();
  }
}

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 =