lib/CodeGen/ModuleBuilder.cpp

   1 //===--- ModuleBuilder.cpp - Emit LLVM Code from ASTs ---------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This builds an AST and converts it to LLVM Code.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "clang/CodeGen/ModuleBuilder.h"
  15 #include "CodeGenModule.h"
  16 #include "clang/Frontend/CodeGenOptions.h"
  17 #include "clang/AST/ASTContext.h"
  18 #include "clang/AST/DeclObjC.h"
  19 #include "clang/AST/Expr.h"
  20 #include "clang/Basic/Diagnostic.h"
  21 #include "clang/Basic/TargetInfo.h"
  22 #include "llvm/LLVMContext.h"
  23 #include "llvm/Module.h"
  24 #include "llvm/Target/TargetData.h"
  25 #include "llvm/ADT/OwningPtr.h"
  26 using namespace clang;
  27
  28 namespace {
  29   class CodeGeneratorImpl : public CodeGenerator {
  30     Diagnostic &Diags;
  31     llvm::OwningPtr<const llvm::TargetData> TD;
  32     ASTContext *Ctx;
  33     const CodeGenOptions CodeGenOpts;  // Intentionally copied in.
  34   protected:
  35     llvm::OwningPtr<llvm::Module> M;
  36     llvm::OwningPtr<CodeGen::CodeGenModule> Builder;
  37   public:
  38     CodeGeneratorImpl(Diagnostic &diags, const std::string& ModuleName,
  39                       const CodeGenOptions &CGO, llvm::LLVMContext& C)
  40       : Diags(diags), CodeGenOpts(CGO), M(new llvm::Module(ModuleName, C)) {}
  41
  42     virtual ~CodeGeneratorImpl() {}
  43
  44     virtual llvm::Module* GetModule() {
  45       return M.get();
  46     }
  47
  48     virtual llvm::Module* ReleaseModule() {
  49       return M.take();
  50     }
  51
  52     virtual void Initialize(ASTContext &Context) {
  53       Ctx = &Context;
  54
  55       M->setTargetTriple(Ctx->Target.getTriple().getTriple());
  56       M->setDataLayout(Ctx->Target.getTargetDescription());
  57       TD.reset(new llvm::TargetData(Ctx->Target.getTargetDescription()));
  58       Builder.reset(new CodeGen::CodeGenModule(Context, CodeGenOpts,
  59                                                *M, *TD, Diags));
  60     }
  61
  62     virtual void HandleTopLevelDecl(DeclGroupRef DG) {
  63       // Make sure to emit all elements of a Decl.
  64       for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
  65         Builder->EmitTopLevelDecl(*I);
  66     }
  67
  68     /// HandleTagDeclDefinition - This callback is invoked each time a TagDecl
  69     /// to (e.g. struct, union, enum, class) is completed. This allows the
  70     /// client hack on the type, which can occur at any point in the file
  71     /// (because these can be defined in declspecs).
  72     virtual void HandleTagDeclDefinition(TagDecl *D) {
  73       Builder->UpdateCompletedType(D);
  74
  75       // In C++, we may have member functions that need to be emitted at this
  76       // point.
  77       if (Ctx->getLangOptions().CPlusPlus && !D->isDependentContext()) {
  78         for (DeclContext::decl_iterator M = D->decls_begin(),
  79                                      MEnd = D->decls_end();
  80              M != MEnd; ++M)
  81           if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*M))
  82             if (Method->isThisDeclarationADefinition() &&
  83                 Method->hasAttr<UsedAttr>())
  84               Builder->EmitTopLevelDecl(Method);
  85       }
  86     }
  87
  88     virtual void HandleTranslationUnit(ASTContext &Ctx) {
  89       if (Diags.hasErrorOccurred()) {
  90         M.reset();
  91         return;
  92       }
  93
  94       if (Builder)
  95         Builder->Release();
  96     }
  97
  98     virtual void CompleteTentativeDefinition(VarDecl *D) {
  99       if (Diags.hasErrorOccurred())
 100         return;
 101
 102       Builder->EmitTentativeDefinition(D);
 103     }
 104
 105     virtual void HandleVTable(CXXRecordDecl *RD, bool DefinitionRequired) {
 106       if (Diags.hasErrorOccurred())
 107         return;
 108
 109       Builder->EmitVTable(RD, DefinitionRequired);
 110     }
 111   };
 112 }
 113
 114 CodeGenerator *clang::CreateLLVMCodeGen(Diagnostic &Diags,
 115                                         const std::string& ModuleName,
 116                                         const CodeGenOptions &CGO,
 117                                         llvm::LLVMContext& C) {
 118   return new CodeGeneratorImpl(Diags, ModuleName, CGO, C);
 119 }