1 //===--- InterfaceStubFunctionsConsumer.cpp -------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "clang/AST/Mangle.h" 10 #include "clang/AST/RecursiveASTVisitor.h" 11 #include "clang/Frontend/CompilerInstance.h" 12 #include "clang/Frontend/FrontendActions.h" 13 #include "clang/Sema/TemplateInstCallback.h" 14 #include "llvm/BinaryFormat/ELF.h" 15 16 using namespace clang; 17 18 namespace { 19 class InterfaceStubFunctionsConsumer : public ASTConsumer { 20 CompilerInstance &Instance; 21 StringRef InFile; 22 StringRef Format; 23 std::set<std::string> ParsedTemplates; 24 25 enum RootDeclOrigin { TopLevel = 0, FromTU = 1, IsLate = 2 }; 26 struct MangledSymbol { 27 std::string ParentName; 28 uint8_t Type; 29 uint8_t Binding; 30 std::vector<std::string> Names; 31 MangledSymbol() = delete; 32 33 MangledSymbol(const std::string &ParentName, uint8_t Type, uint8_t Binding, 34 std::vector<std::string> Names) 35 : ParentName(ParentName), Type(Type), Binding(Binding), Names(Names) {} 36 }; 37 using MangledSymbols = std::map<const NamedDecl *, MangledSymbol>; 38 39 bool WriteNamedDecl(const NamedDecl *ND, MangledSymbols &Symbols, int RDO) { 40 // Here we filter out anything that's not set to DefaultVisibility. 41 // DefaultVisibility is set on a decl when -fvisibility is not specified on 42 // the command line (or specified as default) and the decl does not have 43 // __attribute__((visibility("hidden"))) set or when the command line 44 // argument is set to hidden but the decl explicitly has 45 // __attribute__((visibility ("default"))) set. We do this so that the user 46 // can have fine grain control of what they want to expose in the stub. 47 auto isVisible = [](const NamedDecl *ND) -> bool { 48 return ND->getVisibility() == DefaultVisibility; 49 }; 50 51 auto ignoreDecl = [this, isVisible](const NamedDecl *ND) -> bool { 52 if (!isVisible(ND)) 53 return true; 54 55 if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) 56 if ((VD->getStorageClass() == StorageClass::SC_Extern) || 57 (VD->getStorageClass() == StorageClass::SC_Static && 58 VD->getParentFunctionOrMethod() == nullptr)) 59 return true; 60 61 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) { 62 if (FD->isInlined() && !isa<CXXMethodDecl>(FD) && 63 !Instance.getLangOpts().GNUInline) 64 return true; 65 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { 66 if (const auto *RC = dyn_cast<CXXRecordDecl>(MD->getParent())) 67 if (isa<ClassTemplateDecl>(RC->getParent()) || !isVisible(RC)) 68 return true; 69 if (MD->isDependentContext() || !MD->hasBody()) 70 return true; 71 } 72 if (FD->getStorageClass() == StorageClass::SC_Static) 73 return true; 74 } 75 return false; 76 }; 77 78 auto getParentFunctionDecl = [](const NamedDecl *ND) -> const NamedDecl * { 79 if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) 80 if (const auto *FD = 81 dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod())) 82 return FD; 83 return nullptr; 84 }; 85 86 auto getMangledNames = [](const NamedDecl *ND) -> std::vector<std::string> { 87 if (!ND) 88 return {""}; 89 ASTNameGenerator NameGen(ND->getASTContext()); 90 std::vector<std::string> MangledNames = NameGen.getAllManglings(ND); 91 if (isa<CXXConstructorDecl>(ND) || isa<CXXDestructorDecl>(ND)) 92 return MangledNames; 93 #ifdef EXPENSIVE_CHECKS 94 assert(MangledNames.size() <= 1 && "Expected only one name mangling."); 95 #endif 96 return {NameGen.getName(ND)}; 97 }; 98 99 if (!(RDO & FromTU)) 100 return true; 101 if (Symbols.find(ND) != Symbols.end()) 102 return true; 103 // - Currently have not figured out how to produce the names for FieldDecls. 104 // - Do not want to produce symbols for function paremeters. 105 if (isa<FieldDecl>(ND) || isa<ParmVarDecl>(ND)) 106 return true; 107 108 const NamedDecl *ParentDecl = getParentFunctionDecl(ND); 109 if ((ParentDecl && ignoreDecl(ParentDecl)) || ignoreDecl(ND)) 110 return true; 111 112 if (RDO & IsLate) { 113 Instance.getDiagnostics().Report(diag::err_asm_invalid_type_in_input) 114 << "Generating Interface Stubs is not supported with " 115 "delayed template parsing."; 116 } else { 117 if (const auto *FD = dyn_cast<FunctionDecl>(ND)) 118 if (FD->isDependentContext()) 119 return true; 120 121 const bool IsWeak = (ND->hasAttr<WeakAttr>() || 122 ND->hasAttr<WeakRefAttr>() || ND->isWeakImported()); 123 124 Symbols.insert(std::make_pair( 125 ND, 126 MangledSymbol(getMangledNames(ParentDecl).front(), 127 // Type: 128 isa<VarDecl>(ND) ? llvm::ELF::STT_OBJECT 129 : llvm::ELF::STT_FUNC, 130 // Binding: 131 IsWeak ? llvm::ELF::STB_WEAK : llvm::ELF::STB_GLOBAL, 132 getMangledNames(ND)))); 133 } 134 return true; 135 } 136 137 void 138 HandleDecls(const llvm::iterator_range<DeclContext::decl_iterator> &Decls, 139 MangledSymbols &Symbols, int RDO) { 140 for (const auto *D : Decls) 141 HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO); 142 } 143 144 void HandleTemplateSpecializations(const FunctionTemplateDecl &FTD, 145 MangledSymbols &Symbols, int RDO) { 146 for (const auto *D : FTD.specializations()) 147 HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO); 148 } 149 150 void HandleTemplateSpecializations(const ClassTemplateDecl &CTD, 151 MangledSymbols &Symbols, int RDO) { 152 for (const auto *D : CTD.specializations()) 153 HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO); 154 } 155 156 bool HandleNamedDecl(const NamedDecl *ND, MangledSymbols &Symbols, int RDO) { 157 if (!ND) 158 return false; 159 160 switch (ND->getKind()) { 161 default: 162 break; 163 case Decl::Kind::Namespace: 164 HandleDecls(cast<NamespaceDecl>(ND)->decls(), Symbols, RDO); 165 return true; 166 case Decl::Kind::CXXRecord: 167 HandleDecls(cast<CXXRecordDecl>(ND)->decls(), Symbols, RDO); 168 return true; 169 case Decl::Kind::ClassTemplateSpecialization: 170 HandleDecls(cast<ClassTemplateSpecializationDecl>(ND)->decls(), Symbols, 171 RDO); 172 return true; 173 case Decl::Kind::ClassTemplate: 174 HandleTemplateSpecializations(*cast<ClassTemplateDecl>(ND), Symbols, RDO); 175 return true; 176 case Decl::Kind::FunctionTemplate: 177 HandleTemplateSpecializations(*cast<FunctionTemplateDecl>(ND), Symbols, 178 RDO); 179 return true; 180 case Decl::Kind::TemplateTypeParm: 181 return true; 182 case Decl::Kind::Var: 183 case Decl::Kind::ParmVar: 184 case Decl::Kind::CXXMethod: 185 case Decl::Kind::CXXConstructor: 186 case Decl::Kind::CXXDestructor: 187 case Decl::Kind::Function: 188 case Decl::Kind::Field: 189 if (WriteNamedDecl(ND, Symbols, RDO)) 190 return true; 191 } 192 193 // While interface stubs are in the development stage, it's probably best to 194 // catch anything that's not a VarDecl or Template/FunctionDecl. 195 Instance.getDiagnostics().Report(diag::err_asm_invalid_type_in_input) 196 << "Expected a function or function template decl."; 197 return false; 198 } 199 200 public: 201 InterfaceStubFunctionsConsumer(CompilerInstance &Instance, StringRef InFile, 202 StringRef Format) 203 : Instance(Instance), InFile(InFile), Format(Format) {} 204 205 void HandleTranslationUnit(ASTContext &context) override { 206 struct Visitor : public RecursiveASTVisitor<Visitor> { 207 bool VisitNamedDecl(NamedDecl *ND) { 208 if (const auto *FD = dyn_cast<FunctionDecl>(ND)) 209 if (FD->isLateTemplateParsed()) { 210 LateParsedDecls.insert(FD); 211 return true; 212 } 213 214 if (const auto *VD = dyn_cast<ValueDecl>(ND)) { 215 ValueDecls.insert(VD); 216 return true; 217 } 218 219 NamedDecls.insert(ND); 220 return true; 221 } 222 223 std::set<const NamedDecl *> LateParsedDecls; 224 std::set<NamedDecl *> NamedDecls; 225 std::set<const ValueDecl *> ValueDecls; 226 } v; 227 228 v.TraverseDecl(context.getTranslationUnitDecl()); 229 230 MangledSymbols Symbols; 231 auto OS = Instance.createDefaultOutputFile(/*Binary=*/false, InFile, "ifs"); 232 if (!OS) 233 return; 234 235 if (Instance.getLangOpts().DelayedTemplateParsing) { 236 clang::Sema &S = Instance.getSema(); 237 for (const auto *FD : v.LateParsedDecls) { 238 clang::LateParsedTemplate &LPT = 239 *S.LateParsedTemplateMap.find(cast<FunctionDecl>(FD))->second; 240 S.LateTemplateParser(S.OpaqueParser, LPT); 241 HandleNamedDecl(FD, Symbols, (FromTU | IsLate)); 242 } 243 } 244 245 for (const NamedDecl *ND : v.ValueDecls) 246 HandleNamedDecl(ND, Symbols, FromTU); 247 for (const NamedDecl *ND : v.NamedDecls) 248 HandleNamedDecl(ND, Symbols, FromTU); 249 250 auto writeIfsV1 = 251 [this](const llvm::Triple &T, const MangledSymbols &Symbols, 252 const ASTContext &context, StringRef Format, 253 raw_ostream &OS) -> void { 254 OS << "--- !" << Format << "\n"; 255 OS << "IfsVersion: 1.0\n"; 256 OS << "Triple: " << T.str() << "\n"; 257 OS << "ObjectFileFormat: " << "ELF" << "\n"; // TODO: For now, just ELF. 258 OS << "Symbols:\n"; 259 for (const auto &E : Symbols) { 260 const MangledSymbol &Symbol = E.second; 261 for (auto Name : Symbol.Names) { 262 OS << " " 263 << (Symbol.ParentName.empty() || Instance.getLangOpts().CPlusPlus 264 ? "" 265 : (Symbol.ParentName + ".")) 266 << Name << ": { Type: "; 267 switch (Symbol.Type) { 268 default: 269 llvm_unreachable( 270 "clang -emit-iterface-stubs: Unexpected symbol type."); 271 case llvm::ELF::STT_NOTYPE: 272 OS << "NoType"; 273 break; 274 case llvm::ELF::STT_OBJECT: { 275 auto VD = cast<ValueDecl>(E.first)->getType(); 276 OS << "Object, Size: " 277 << context.getTypeSizeInChars(VD).getQuantity(); 278 break; 279 } 280 case llvm::ELF::STT_FUNC: 281 OS << "Func"; 282 break; 283 } 284 if (Symbol.Binding == llvm::ELF::STB_WEAK) 285 OS << ", Weak: true"; 286 OS << " }\n"; 287 } 288 } 289 OS << "...\n"; 290 OS.flush(); 291 }; 292 293 assert(Format == "experimental-ifs-v1" && "Unexpected IFS Format."); 294 writeIfsV1(Instance.getTarget().getTriple(), Symbols, context, Format, *OS); 295 } 296 }; 297 } // namespace 298 299 std::unique_ptr<ASTConsumer> 300 GenerateInterfaceIfsExpV1Action::CreateASTConsumer(CompilerInstance &CI, 301 StringRef InFile) { 302 return std::make_unique<InterfaceStubFunctionsConsumer>( 303 CI, InFile, "experimental-ifs-v1"); 304 } 305