xref: /llvm-project/clang/lib/CodeGen/ModuleBuilder.cpp (revision 5d041beb4e86787b55236d9cf3259fef17423323)
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/DeclObjC.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/Basic/Diagnostic.h"
20 #include "clang/Basic/TargetInfo.h"
21 #include "clang/Frontend/CodeGenOptions.h"
22 #include "llvm/ADT/OwningPtr.h"
23 #include "llvm/ADT/StringRef.h"
24 #include "llvm/IR/DataLayout.h"
25 #include "llvm/IR/LLVMContext.h"
26 #include "llvm/IR/Module.h"
27 using namespace clang;
28 
29 namespace {
30   class CodeGeneratorImpl : public CodeGenerator {
31     DiagnosticsEngine &Diags;
32     OwningPtr<const llvm::DataLayout> TD;
33     ASTContext *Ctx;
34     const CodeGenOptions CodeGenOpts;  // Intentionally copied in.
35   protected:
36     OwningPtr<llvm::Module> M;
37     OwningPtr<CodeGen::CodeGenModule> Builder;
38   public:
39     CodeGeneratorImpl(DiagnosticsEngine &diags, const std::string& ModuleName,
40                       const CodeGenOptions &CGO, llvm::LLVMContext& C)
41       : Diags(diags), CodeGenOpts(CGO),
42         M(new llvm::Module(ModuleName, C)) {}
43 
44     virtual ~CodeGeneratorImpl() {}
45 
46     virtual llvm::Module* GetModule() {
47       return M.get();
48     }
49 
50     virtual llvm::Module* ReleaseModule() {
51       return M.take();
52     }
53 
54     virtual void Initialize(ASTContext &Context) {
55       Ctx = &Context;
56 
57       M->setTargetTriple(Ctx->getTargetInfo().getTriple().getTriple());
58       M->setDataLayout(Ctx->getTargetInfo().getTargetDescription());
59       TD.reset(new llvm::DataLayout(Ctx->getTargetInfo().getTargetDescription()));
60       Builder.reset(new CodeGen::CodeGenModule(Context, CodeGenOpts, *M, *TD,
61                                                Diags));
62     }
63 
64     virtual void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
65       Builder->HandleCXXStaticMemberVarInstantiation(VD);
66     }
67 
68     virtual bool HandleTopLevelDecl(DeclGroupRef DG) {
69       // Make sure to emit all elements of a Decl.
70       for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
71         Builder->EmitTopLevelDecl(*I);
72       return true;
73     }
74 
75     /// HandleTagDeclDefinition - This callback is invoked each time a TagDecl
76     /// to (e.g. struct, union, enum, class) is completed. This allows the
77     /// client hack on the type, which can occur at any point in the file
78     /// (because these can be defined in declspecs).
79     virtual void HandleTagDeclDefinition(TagDecl *D) {
80       Builder->UpdateCompletedType(D);
81 
82       // In C++, we may have member functions that need to be emitted at this
83       // point.
84       if (Ctx->getLangOpts().CPlusPlus && !D->isDependentContext()) {
85         for (DeclContext::decl_iterator M = D->decls_begin(),
86                                      MEnd = D->decls_end();
87              M != MEnd; ++M)
88           if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*M))
89             if (Method->doesThisDeclarationHaveABody() &&
90                 (Method->hasAttr<UsedAttr>() ||
91                  Method->hasAttr<ConstructorAttr>()))
92               Builder->EmitTopLevelDecl(Method);
93       }
94     }
95 
96     virtual void HandleTranslationUnit(ASTContext &Ctx) {
97       if (Diags.hasErrorOccurred()) {
98         M.reset();
99         return;
100       }
101 
102       if (Builder)
103         Builder->Release();
104     }
105 
106     virtual void CompleteTentativeDefinition(VarDecl *D) {
107       if (Diags.hasErrorOccurred())
108         return;
109 
110       Builder->EmitTentativeDefinition(D);
111     }
112 
113     virtual void HandleVTable(CXXRecordDecl *RD, bool DefinitionRequired) {
114       if (Diags.hasErrorOccurred())
115         return;
116 
117       Builder->EmitVTable(RD, DefinitionRequired);
118     }
119 
120     virtual void HandleLinkerOptionPragma(llvm::StringRef Opts) {
121       Builder->AppendLinkerOptions(Opts);
122     }
123 
124     virtual void HandleDetectMismatch(llvm::StringRef Name,
125                                       llvm::StringRef Value) {
126       Builder->AddDetectMismatch(Name, Value);
127     }
128 
129     virtual void HandleDependentLibrary(llvm::StringRef Lib) {
130       Builder->AddDependentLib(Lib);
131     }
132   };
133 }
134 
135 void CodeGenerator::anchor() { }
136 
137 CodeGenerator *clang::CreateLLVMCodeGen(DiagnosticsEngine &Diags,
138                                         const std::string& ModuleName,
139                                         const CodeGenOptions &CGO,
140                                         const TargetOptions &/*TO*/,
141                                         llvm::LLVMContext& C) {
142   return new CodeGeneratorImpl(Diags, ModuleName, CGO, C);
143 }
144