xref: /llvm-project/clang/lib/CodeGen/ModuleBuilder.cpp (revision 2c674f6dbb086a813b32cd66a8be49407ff4f576)
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/ASTContext.h"
17 #include "clang/AST/Decl.h"
18 using namespace clang;
19 
20 //===----------------------------------------------------------------------===//
21 // LLVM Emitter
22 
23 #include "clang/Basic/Diagnostic.h"
24 #include "clang/Basic/TargetInfo.h"
25 #include "clang/CodeGen/ModuleBuilder.h"
26 #include "llvm/Module.h"
27 #include "llvm/Target/TargetData.h"
28 #include "llvm/Target/TargetMachine.h"
29 #include "llvm/Support/Compiler.h"
30 #include "llvm/ADT/OwningPtr.h"
31 
32 
33 namespace {
34   class VISIBILITY_HIDDEN CodeGeneratorImpl : public CodeGenerator {
35     Diagnostic &Diags;
36     llvm::OwningPtr<const llvm::TargetData> TD;
37     ASTContext *Ctx;
38     const LangOptions &Features;
39     bool GenerateDebugInfo;
40   protected:
41     llvm::OwningPtr<llvm::Module> M;
42     llvm::OwningPtr<CodeGen::CodeGenModule> Builder;
43   public:
44     CodeGeneratorImpl(Diagnostic &diags, const LangOptions &LO,
45                       const std::string& ModuleName,
46                       bool DebugInfoFlag)
47     : Diags(diags), Features(LO), GenerateDebugInfo(DebugInfoFlag),
48       M(new llvm::Module(ModuleName)) {}
49 
50     virtual ~CodeGeneratorImpl() {}
51 
52     virtual llvm::Module* ReleaseModule() {
53       if (Diags.hasErrorOccurred())
54         return 0;
55 
56       if (Builder)
57         Builder->Release();
58 
59       return M.take();
60     }
61 
62     virtual void Initialize(ASTContext &Context) {
63       Ctx = &Context;
64 
65       M->setTargetTriple(Ctx->Target.getTargetTriple());
66       M->setDataLayout(Ctx->Target.getTargetDescription());
67       TD.reset(new llvm::TargetData(Ctx->Target.getTargetDescription()));
68       Builder.reset(new CodeGen::CodeGenModule(Context, Features, *M, *TD,
69                                                Diags, GenerateDebugInfo));
70     }
71 
72     virtual void HandleTopLevelDecl(Decl *D) {
73       // If an error occurred, stop code generation, but continue parsing and
74       // semantic analysis (to ensure all warnings and errors are emitted).
75       if (Diags.hasErrorOccurred())
76         return;
77 
78       if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
79         Builder->EmitGlobal(FD);
80       } else if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
81         Builder->EmitGlobal(VD);
82       } else if (isa<ObjCClassDecl>(D)){
83         //Forward declaration.  Only used for type checking.
84       } else if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D)){
85         // Generate Protocol object.
86         Builder->EmitObjCProtocolImplementation(PD);
87       } else if (isa<ObjCCategoryDecl>(D)){
88         //Only used for typechecking.
89       } else if (ObjCCategoryImplDecl *OCD = dyn_cast<ObjCCategoryImplDecl>(D)){
90         // Generate methods, attach to category structure
91         Builder->EmitObjCCategoryImpl(OCD);
92       } else if (ObjCImplementationDecl * OID =
93           dyn_cast<ObjCImplementationDecl>(D)){
94         // Generate methods, attach to class structure
95         Builder->EmitObjCClassImplementation(OID);
96       } else if (isa<ObjCInterfaceDecl>(D)){
97         // Ignore - generated when the implementation decl is CodeGen'd
98       } else if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D)){
99         Builder->EmitObjCMethod(OMD);
100       } else if (isa<ObjCClassDecl>(D) || isa<ObjCCategoryDecl>(D)) {
101         // Forward declaration.  Only used for type checking.
102       } else if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D)){
103         Builder->EmitObjCMethod(OMD);
104       } else if (LinkageSpecDecl *LSD = dyn_cast<LinkageSpecDecl>(D)) {
105         if (LSD->getLanguage() == LinkageSpecDecl::lang_cxx)
106           Builder->WarnUnsupported(LSD, "linkage spec");
107         // FIXME: implement C++ linkage, C linkage works mostly by C
108         // language reuse already.
109       } else if (FileScopeAsmDecl *AD = dyn_cast<FileScopeAsmDecl>(D)) {
110         std::string AsmString(AD->getAsmString()->getStrData(),
111                               AD->getAsmString()->getByteLength());
112 
113         const std::string &S = Builder->getModule().getModuleInlineAsm();
114         if (S.empty())
115           Builder->getModule().setModuleInlineAsm(AsmString);
116         else
117           Builder->getModule().setModuleInlineAsm(S + '\n' + AsmString);
118       } else {
119         assert(isa<TypeDecl>(D) && "Unknown top level decl");
120         // TODO: handle debug info?
121       }
122 
123       if (ScopedDecl *SD = dyn_cast<ScopedDecl>(D)) {
124         SD = SD->getNextDeclarator();
125         if (SD)
126           HandleTopLevelDecl(SD);
127       }
128     }
129 
130     /// HandleTagDeclDefinition - This callback is invoked each time a TagDecl
131     /// (e.g. struct, union, enum, class) is completed.  This allows the client to
132     /// hack on the type, which can occur at any point in the file (because these
133     /// can be defined in declspecs).
134     virtual void HandleTagDeclDefinition(TagDecl *D) {
135       Builder->UpdateCompletedType(D);
136     }
137 
138   };
139 }
140 
141 CodeGenerator *clang::CreateLLVMCodeGen(Diagnostic &Diags,
142                                         const LangOptions &Features,
143                                         const std::string& ModuleName,
144                                         bool GenerateDebugInfo) {
145   return new CodeGeneratorImpl(Diags, Features, ModuleName, GenerateDebugInfo);
146 }
147