xref: /llvm-project/clang/lib/CodeGen/ModuleBuilder.cpp (revision 629afaefe0cd1a583ccee54918b7b13f48bfe273)
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 "CGDebugInfo.h"
16 #include "CodeGenModule.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 "clang/Frontend/CodeGenOptions.h"
23 #include "llvm/ADT/OwningPtr.h"
24 #include "llvm/ADT/StringRef.h"
25 #include "llvm/IR/DataLayout.h"
26 #include "llvm/IR/LLVMContext.h"
27 #include "llvm/IR/Module.h"
28 using namespace clang;
29 
30 namespace {
31   class CodeGeneratorImpl : public CodeGenerator {
32     DiagnosticsEngine &Diags;
33     OwningPtr<const llvm::DataLayout> TD;
34     ASTContext *Ctx;
35     const CodeGenOptions CodeGenOpts;  // Intentionally copied in.
36   protected:
37     OwningPtr<llvm::Module> M;
38     OwningPtr<CodeGen::CodeGenModule> Builder;
39   public:
40     CodeGeneratorImpl(DiagnosticsEngine &diags, const std::string& ModuleName,
41                       const CodeGenOptions &CGO, llvm::LLVMContext& C)
42       : Diags(diags), CodeGenOpts(CGO),
43         M(new llvm::Module(ModuleName, C)) {}
44 
45     virtual ~CodeGeneratorImpl() {}
46 
47     virtual llvm::Module* GetModule() {
48       return M.get();
49     }
50 
51     virtual llvm::Module *ReleaseModule() { return M.release(); }
52 
53     virtual void Initialize(ASTContext &Context) {
54       Ctx = &Context;
55 
56       M->setTargetTriple(Ctx->getTargetInfo().getTriple().getTriple());
57       M->setDataLayout(Ctx->getTargetInfo().getTargetDescription());
58       TD.reset(new llvm::DataLayout(Ctx->getTargetInfo().getTargetDescription()));
59       Builder.reset(new CodeGen::CodeGenModule(Context, CodeGenOpts, *M, *TD,
60                                                Diags));
61 
62       for (size_t i = 0, e = CodeGenOpts.DependentLibraries.size(); i < e; ++i)
63         HandleDependentLibrary(CodeGenOpts.DependentLibraries[i]);
64     }
65 
66     virtual void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
67       if (Diags.hasErrorOccurred())
68         return;
69 
70       Builder->HandleCXXStaticMemberVarInstantiation(VD);
71     }
72 
73     virtual bool HandleTopLevelDecl(DeclGroupRef DG) {
74       if (Diags.hasErrorOccurred())
75         return true;
76 
77       // Make sure to emit all elements of a Decl.
78       for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
79         Builder->EmitTopLevelDecl(*I);
80       return true;
81     }
82 
83     /// HandleTagDeclDefinition - This callback is invoked each time a TagDecl
84     /// to (e.g. struct, union, enum, class) is completed. This allows the
85     /// client hack on the type, which can occur at any point in the file
86     /// (because these can be defined in declspecs).
87     virtual void HandleTagDeclDefinition(TagDecl *D) {
88       if (Diags.hasErrorOccurred())
89         return;
90 
91       Builder->UpdateCompletedType(D);
92 
93       // In C++, we may have member functions that need to be emitted at this
94       // point.
95       if (Ctx->getLangOpts().CPlusPlus && !D->isDependentContext()) {
96         for (auto *M : D->decls())
97           if (auto *Method = dyn_cast<CXXMethodDecl>(M))
98             if (Method->doesThisDeclarationHaveABody() &&
99                 (Method->hasAttr<UsedAttr>() ||
100                  Method->hasAttr<ConstructorAttr>()))
101               Builder->EmitTopLevelDecl(Method);
102       }
103     }
104 
105     virtual void HandleTagDeclRequiredDefinition(const TagDecl *D) override {
106       if (Diags.hasErrorOccurred())
107         return;
108 
109       if (CodeGen::CGDebugInfo *DI = Builder->getModuleDebugInfo())
110         if (const RecordDecl *RD = dyn_cast<RecordDecl>(D))
111           DI->completeRequiredType(RD);
112     }
113 
114     virtual void HandleTranslationUnit(ASTContext &Ctx) {
115       if (Diags.hasErrorOccurred()) {
116         if (Builder)
117           Builder->clear();
118         M.reset();
119         return;
120       }
121 
122       if (Builder)
123         Builder->Release();
124     }
125 
126     virtual void CompleteTentativeDefinition(VarDecl *D) {
127       if (Diags.hasErrorOccurred())
128         return;
129 
130       Builder->EmitTentativeDefinition(D);
131     }
132 
133     virtual void HandleVTable(CXXRecordDecl *RD, bool DefinitionRequired) {
134       if (Diags.hasErrorOccurred())
135         return;
136 
137       Builder->EmitVTable(RD, DefinitionRequired);
138     }
139 
140     virtual void HandleLinkerOptionPragma(llvm::StringRef Opts) {
141       Builder->AppendLinkerOptions(Opts);
142     }
143 
144     virtual void HandleDetectMismatch(llvm::StringRef Name,
145                                       llvm::StringRef Value) {
146       Builder->AddDetectMismatch(Name, Value);
147     }
148 
149     virtual void HandleDependentLibrary(llvm::StringRef Lib) {
150       Builder->AddDependentLib(Lib);
151     }
152   };
153 }
154 
155 void CodeGenerator::anchor() { }
156 
157 CodeGenerator *clang::CreateLLVMCodeGen(DiagnosticsEngine &Diags,
158                                         const std::string& ModuleName,
159                                         const CodeGenOptions &CGO,
160                                         const TargetOptions &/*TO*/,
161                                         llvm::LLVMContext& C) {
162   return new CodeGeneratorImpl(Diags, ModuleName, CGO, C);
163 }
164