xref: /llvm-project/clang/lib/CodeGen/ModuleBuilder.cpp (revision 3e1d35b92d507423b88172a96aef2d8e817b2db2)
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     bool GenerateDebugInfo;
38   protected:
39     llvm::Module *&M;
40     CodeGen::CodeGenModule *Builder;
41   public:
42     CodeGenerator(Diagnostic &diags, const LangOptions &LO,
43                   llvm::Module *&DestModule, bool DebugInfoFlag)
44     : Diags(diags), Features(LO), GenerateDebugInfo(DebugInfoFlag),
45     M(DestModule) {}
46 
47     ~CodeGenerator() {
48       delete Builder;
49       delete TD;
50     }
51 
52     virtual void Initialize(ASTContext &Context) {
53       Ctx = &Context;
54 
55       M->setTargetTriple(Ctx->Target.getTargetTriple());
56       M->setDataLayout(Ctx->Target.getTargetDescription());
57       TD = new llvm::TargetData(Ctx->Target.getTargetDescription());
58       Builder = new CodeGen::CodeGenModule(Context, Features, *M, *TD, Diags,
59                                            GenerateDebugInfo);
60     }
61 
62     virtual void HandleTopLevelDecl(Decl *D) {
63       // If an error occurred, stop code generation, but continue parsing and
64       // semantic analysis (to ensure all warnings and errors are emitted).
65       if (Diags.hasErrorOccurred())
66         return;
67 
68       if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
69         Builder->EmitFunction(FD);
70       } else if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
71         if (VD->isFileVarDecl())
72           Builder->EmitGlobalVarDeclarator(VD);
73       } else if (isa<ObjCClassDecl>(D) || isa<ObjCCategoryDecl>(D)) {
74         // Forward declaration.  Only used for type checking.
75       } else if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D)){
76         Builder->EmitObjCMethod(OMD);
77       } else if (LinkageSpecDecl *LSD = dyn_cast<LinkageSpecDecl>(D)) {
78         if (LSD->getLanguage() == LinkageSpecDecl::lang_cxx)
79           Builder->WarnUnsupported(LSD, "linkage spec");
80         // FIXME: implement C++ linkage, C linkage works mostly by C
81         // language reuse already.
82       } else if (FileScopeAsmDecl *AD = dyn_cast<FileScopeAsmDecl>(D)) {
83         std::string AsmString(AD->getAsmString()->getStrData(),
84                               AD->getAsmString()->getByteLength());
85 
86         const std::string &S = Builder->getModule().getModuleInlineAsm();
87         if (S.empty())
88           Builder->getModule().setModuleInlineAsm(AsmString);
89         else
90           Builder->getModule().setModuleInlineAsm(S + '\n' + AsmString);
91       } else {
92         assert(isa<TypeDecl>(D) && "Unknown top level decl");
93         // TODO: handle debug info?
94       }
95     }
96 
97     /// HandleTagDeclDefinition - This callback is invoked each time a TagDecl
98     /// (e.g. struct, union, enum, class) is completed.  This allows the client to
99     /// hack on the type, which can occur at any point in the file (because these
100     /// can be defined in declspecs).
101     virtual void HandleTagDeclDefinition(TagDecl *D) {
102       Builder->UpdateCompletedType(D);
103     }
104 
105   };
106 }
107 
108 ASTConsumer *clang::CreateLLVMCodeGen(Diagnostic &Diags,
109                                       const LangOptions &Features,
110                                       llvm::Module *&DestModule,
111                                       bool GenerateDebugInfo) {
112   return new CodeGenerator(Diags, Features, DestModule, GenerateDebugInfo);
113 }
114 
115