1 //===- CodegenNameGenerator.cpp - Codegen name generation -----------------===//
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 // Determines the name that the symbol will get for code generation.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "clang/Index/CodegenNameGenerator.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/DeclCXX.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/Mangle.h"
19 #include "clang/AST/VTableBuilder.h"
20 #include "clang/Basic/TargetInfo.h"
21 #include "llvm/IR/DataLayout.h"
22 #include "llvm/IR/Mangler.h"
23 #include "llvm/Support/raw_ostream.h"
24
25 using namespace clang;
26 using namespace clang::index;
27
28 struct CodegenNameGenerator::Implementation {
29 std::unique_ptr<MangleContext> MC;
30 llvm::DataLayout DL;
31
ImplementationCodegenNameGenerator::Implementation32 Implementation(ASTContext &Ctx)
33 : MC(Ctx.createMangleContext()),
34 DL(Ctx.getTargetInfo().getDataLayout()) {}
35
writeNameCodegenNameGenerator::Implementation36 bool writeName(const Decl *D, raw_ostream &OS) {
37 // First apply frontend mangling.
38 SmallString<128> FrontendBuf;
39 llvm::raw_svector_ostream FrontendBufOS(FrontendBuf);
40 if (auto *FD = dyn_cast<FunctionDecl>(D)) {
41 if (FD->isDependentContext())
42 return true;
43 if (writeFuncOrVarName(FD, FrontendBufOS))
44 return true;
45 } else if (auto *VD = dyn_cast<VarDecl>(D)) {
46 if (writeFuncOrVarName(VD, FrontendBufOS))
47 return true;
48 } else if (auto *MD = dyn_cast<ObjCMethodDecl>(D)) {
49 MC->mangleObjCMethodNameWithoutSize(MD, OS);
50 return false;
51 } else if (auto *ID = dyn_cast<ObjCInterfaceDecl>(D)) {
52 writeObjCClassName(ID, FrontendBufOS);
53 } else {
54 return true;
55 }
56
57 // Now apply backend mangling.
58 llvm::Mangler::getNameWithPrefix(OS, FrontendBufOS.str(), DL);
59 return false;
60 }
61
getNameCodegenNameGenerator::Implementation62 std::string getName(const Decl *D) {
63 std::string Name;
64 {
65 llvm::raw_string_ostream OS(Name);
66 writeName(D, OS);
67 }
68 return Name;
69 }
70
71 enum ObjCKind {
72 ObjCClass,
73 ObjCMetaclass,
74 };
75
getAllManglingsCodegenNameGenerator::Implementation76 std::vector<std::string> getAllManglings(const ObjCContainerDecl *OCD) {
77 StringRef ClassName;
78 if (const auto *OID = dyn_cast<ObjCInterfaceDecl>(OCD))
79 ClassName = OID->getObjCRuntimeNameAsString();
80 else if (const auto *OID = dyn_cast<ObjCImplementationDecl>(OCD))
81 ClassName = OID->getObjCRuntimeNameAsString();
82
83 if (ClassName.empty())
84 return {};
85
86 auto Mangle = [&](ObjCKind Kind, StringRef ClassName) -> std::string {
87 SmallString<40> Mangled;
88 auto Prefix = getClassSymbolPrefix(Kind, OCD->getASTContext());
89 llvm::Mangler::getNameWithPrefix(Mangled, Prefix + ClassName, DL);
90 return Mangled.str();
91 };
92
93 return {
94 Mangle(ObjCClass, ClassName),
95 Mangle(ObjCMetaclass, ClassName),
96 };
97 }
98
getAllManglingsCodegenNameGenerator::Implementation99 std::vector<std::string> getAllManglings(const Decl *D) {
100 if (const auto *OCD = dyn_cast<ObjCContainerDecl>(D))
101 return getAllManglings(OCD);
102
103 if (!(isa<CXXRecordDecl>(D) || isa<CXXMethodDecl>(D)))
104 return {};
105
106 const NamedDecl *ND = cast<NamedDecl>(D);
107
108 ASTContext &Ctx = ND->getASTContext();
109 std::unique_ptr<MangleContext> M(Ctx.createMangleContext());
110
111 std::vector<std::string> Manglings;
112
113 auto hasDefaultCXXMethodCC = [](ASTContext &C, const CXXMethodDecl *MD) {
114 auto DefaultCC = C.getDefaultCallingConvention(/*IsVariadic=*/false,
115 /*IsCSSMethod=*/true);
116 auto CC = MD->getType()->getAs<FunctionProtoType>()->getCallConv();
117 return CC == DefaultCC;
118 };
119
120 if (const auto *CD = dyn_cast_or_null<CXXConstructorDecl>(ND)) {
121 Manglings.emplace_back(getMangledStructor(CD, Ctor_Base));
122
123 if (Ctx.getTargetInfo().getCXXABI().isItaniumFamily())
124 if (!CD->getParent()->isAbstract())
125 Manglings.emplace_back(getMangledStructor(CD, Ctor_Complete));
126
127 if (Ctx.getTargetInfo().getCXXABI().isMicrosoft())
128 if (CD->hasAttr<DLLExportAttr>() && CD->isDefaultConstructor())
129 if (!(hasDefaultCXXMethodCC(Ctx, CD) && CD->getNumParams() == 0))
130 Manglings.emplace_back(getMangledStructor(CD, Ctor_DefaultClosure));
131 } else if (const auto *DD = dyn_cast_or_null<CXXDestructorDecl>(ND)) {
132 Manglings.emplace_back(getMangledStructor(DD, Dtor_Base));
133 if (Ctx.getTargetInfo().getCXXABI().isItaniumFamily()) {
134 Manglings.emplace_back(getMangledStructor(DD, Dtor_Complete));
135 if (DD->isVirtual())
136 Manglings.emplace_back(getMangledStructor(DD, Dtor_Deleting));
137 }
138 } else if (const auto *MD = dyn_cast_or_null<CXXMethodDecl>(ND)) {
139 Manglings.emplace_back(getName(ND));
140 if (MD->isVirtual())
141 if (const auto *TIV = Ctx.getVTableContext()->getThunkInfo(MD))
142 for (const auto &T : *TIV)
143 Manglings.emplace_back(getMangledThunk(MD, T));
144 }
145
146 return Manglings;
147 }
148
149 private:
writeFuncOrVarNameCodegenNameGenerator::Implementation150 bool writeFuncOrVarName(const NamedDecl *D, raw_ostream &OS) {
151 if (MC->shouldMangleDeclName(D)) {
152 if (const auto *CtorD = dyn_cast<CXXConstructorDecl>(D))
153 MC->mangleCXXCtor(CtorD, Ctor_Complete, OS);
154 else if (const auto *DtorD = dyn_cast<CXXDestructorDecl>(D))
155 MC->mangleCXXDtor(DtorD, Dtor_Complete, OS);
156 else
157 MC->mangleName(D, OS);
158 return false;
159 } else {
160 IdentifierInfo *II = D->getIdentifier();
161 if (!II)
162 return true;
163 OS << II->getName();
164 return false;
165 }
166 }
167
writeObjCClassNameCodegenNameGenerator::Implementation168 void writeObjCClassName(const ObjCInterfaceDecl *D, raw_ostream &OS) {
169 OS << getClassSymbolPrefix(ObjCClass, D->getASTContext());
170 OS << D->getObjCRuntimeNameAsString();
171 }
172
getClassSymbolPrefixCodegenNameGenerator::Implementation173 static StringRef getClassSymbolPrefix(ObjCKind Kind, const ASTContext &Context) {
174 if (Context.getLangOpts().ObjCRuntime.isGNUFamily())
175 return Kind == ObjCMetaclass ? "_OBJC_METACLASS_" : "_OBJC_CLASS_";
176 return Kind == ObjCMetaclass ? "OBJC_METACLASS_$_" : "OBJC_CLASS_$_";
177 }
178
getMangledStructorCodegenNameGenerator::Implementation179 std::string getMangledStructor(const NamedDecl *ND, unsigned StructorType) {
180 std::string FrontendBuf;
181 llvm::raw_string_ostream FOS(FrontendBuf);
182
183 if (const auto *CD = dyn_cast_or_null<CXXConstructorDecl>(ND))
184 MC->mangleCXXCtor(CD, static_cast<CXXCtorType>(StructorType), FOS);
185 else if (const auto *DD = dyn_cast_or_null<CXXDestructorDecl>(ND))
186 MC->mangleCXXDtor(DD, static_cast<CXXDtorType>(StructorType), FOS);
187
188 std::string BackendBuf;
189 llvm::raw_string_ostream BOS(BackendBuf);
190
191 llvm::Mangler::getNameWithPrefix(BOS, FOS.str(), DL);
192
193 return BOS.str();
194 }
195
getMangledThunkCodegenNameGenerator::Implementation196 std::string getMangledThunk(const CXXMethodDecl *MD, const ThunkInfo &T) {
197 std::string FrontendBuf;
198 llvm::raw_string_ostream FOS(FrontendBuf);
199
200 MC->mangleThunk(MD, T, FOS);
201
202 std::string BackendBuf;
203 llvm::raw_string_ostream BOS(BackendBuf);
204
205 llvm::Mangler::getNameWithPrefix(BOS, FOS.str(), DL);
206
207 return BOS.str();
208 }
209 };
210
CodegenNameGenerator(ASTContext & Ctx)211 CodegenNameGenerator::CodegenNameGenerator(ASTContext &Ctx)
212 : Impl(new Implementation(Ctx)) {
213 }
214
~CodegenNameGenerator()215 CodegenNameGenerator::~CodegenNameGenerator() {
216 }
217
writeName(const Decl * D,raw_ostream & OS)218 bool CodegenNameGenerator::writeName(const Decl *D, raw_ostream &OS) {
219 return Impl->writeName(D, OS);
220 }
221
getName(const Decl * D)222 std::string CodegenNameGenerator::getName(const Decl *D) {
223 return Impl->getName(D);
224 }
225
getAllManglings(const Decl * D)226 std::vector<std::string> CodegenNameGenerator::getAllManglings(const Decl *D) {
227 return Impl->getAllManglings(D);
228 }
229