xref: /llvm-project/clang/lib/CodeGen/ModuleBuilder.cpp (revision 08899ff85dde961d36bf0c94d07ee3418905d536)
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/AST/ASTConsumer.h"
17 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/Decl.h"
19 using namespace clang;
20 
21 //===----------------------------------------------------------------------===//
22 // LLVM Emitter
23 
24 #include "clang/Basic/Diagnostic.h"
25 #include "clang/Basic/TargetInfo.h"
26 #include "clang/CodeGen/ModuleBuilder.h"
27 #include "llvm/Module.h"
28 #include "llvm/Target/TargetData.h"
29 #include "llvm/Target/TargetMachine.h"
30 
31 namespace {
32   class CodeGenerator : public ASTConsumer {
33     Diagnostic &Diags;
34     const llvm::TargetData *TD;
35     ASTContext *Ctx;
36     const LangOptions &Features;
37   protected:
38     llvm::Module *&M;
39     CodeGen::CodeGenModule *Builder;
40   public:
41     CodeGenerator(Diagnostic &diags, const LangOptions &LO,
42                   llvm::Module *&DestModule)
43     : Diags(diags), Features(LO), M(DestModule) {}
44 
45     ~CodeGenerator() {
46       delete Builder;
47     }
48 
49     virtual void Initialize(ASTContext &Context) {
50       Ctx = &Context;
51 
52       M->setTargetTriple(Ctx->Target.getTargetTriple());
53       M->setDataLayout(Ctx->Target.getTargetDescription());
54       TD = new llvm::TargetData(Ctx->Target.getTargetDescription());
55       Builder = new CodeGen::CodeGenModule(Context, Features, *M, *TD, Diags);
56     }
57 
58     virtual void HandleTopLevelDecl(Decl *D) {
59       // If an error occurred, stop code generation, but continue parsing and
60       // semantic analysis (to ensure all warnings and errors are emitted).
61       if (Diags.hasErrorOccurred())
62         return;
63 
64       if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
65         Builder->EmitFunction(FD);
66       } else if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
67         if (VD->isFileVarDecl())
68           Builder->EmitGlobalVarDeclarator(VD);
69       } else if (isa<ObjCClassDecl>(D) || isa<ObjCCategoryDecl>(D)) {
70         // Forward declaration.  Only used for type checking.
71       } else if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D)){
72         Builder->EmitObjCMethod(OMD);
73       } else if (LinkageSpecDecl *LSD = dyn_cast<LinkageSpecDecl>(D)) {
74         if (LSD->getLanguage() == LinkageSpecDecl::lang_cxx)
75           Builder->WarnUnsupported(LSD, "linkage spec");
76         // FIXME: implement C++ linkage, C linkage works mostly by C
77         // language reuse already.
78       } else if (FileScopeAsmDecl *AD = dyn_cast<FileScopeAsmDecl>(D)) {
79         std::string AsmString(AD->getAsmString()->getStrData(),
80                               AD->getAsmString()->getByteLength());
81 
82         const std::string &S = Builder->getModule().getModuleInlineAsm();
83         if (S.empty())
84           Builder->getModule().setModuleInlineAsm(AsmString);
85         else
86           Builder->getModule().setModuleInlineAsm(S + '\n' + AsmString);
87       } else {
88         assert(isa<TypeDecl>(D) && "Unknown top level decl");
89         // TODO: handle debug info?
90       }
91     }
92 
93     /// HandleTagDeclDefinition - This callback is invoked each time a TagDecl
94     /// (e.g. struct, union, enum, class) is completed.  This allows the client to
95     /// hack on the type, which can occur at any point in the file (because these
96     /// can be defined in declspecs).
97     virtual void HandleTagDeclDefinition(TagDecl *D) {
98       Builder->UpdateCompletedType(D);
99     }
100 
101   };
102 }
103 
104 ASTConsumer *clang::CreateLLVMCodeGen(Diagnostic &Diags,
105                                       const LangOptions &Features,
106                                       llvm::Module *&DestModule) {
107   return new CodeGenerator(Diags, Features, DestModule);
108 }
109 
110