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 62 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) { 63 if (FD->isInlined() && !isa<CXXMethodDecl>(FD) && 64 !Instance.getLangOpts().GNUInline) 65 return true; 66 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { 67 if (const auto *RC = dyn_cast<CXXRecordDecl>(MD->getParent())) 68 if (isa<ClassTemplateDecl>(RC->getParent()) || !isVisible(RC)) 69 return true; 70 if (MD->isDependentContext() || !MD->hasBody()) 71 return true; 72 } 73 if (FD->getStorageClass() == StorageClass::SC_Static) 74 return true; 75 } 76 return false; 77 }; 78 79 auto getParentFunctionDecl = [](const NamedDecl *ND) -> const NamedDecl * { 80 if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) 81 if (const auto *FD = 82 dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod())) 83 return FD; 84 return nullptr; 85 }; 86 87 auto getMangledNames = [](const NamedDecl *ND) -> std::vector<std::string> { 88 if (!ND) 89 return {""}; 90 ASTNameGenerator NameGen(ND->getASTContext()); 91 std::vector<std::string> MangledNames = NameGen.getAllManglings(ND); 92 if (isa<CXXConstructorDecl>(ND) || isa<CXXDestructorDecl>(ND)) 93 return MangledNames; 94 #ifdef EXPENSIVE_CHECKS 95 assert(MangledNames.size() <= 1 && "Expected only one name mangling."); 96 #endif 97 return {NameGen.getName(ND)}; 98 }; 99 100 if (!(RDO & FromTU)) 101 return true; 102 if (Symbols.find(ND) != Symbols.end()) 103 return true; 104 // - Currently have not figured out how to produce the names for FieldDecls. 105 // - Do not want to produce symbols for function paremeters. 106 if (isa<FieldDecl>(ND) || isa<ParmVarDecl>(ND)) 107 return true; 108 109 const NamedDecl *ParentDecl = getParentFunctionDecl(ND); 110 if ((ParentDecl && ignoreDecl(ParentDecl)) || ignoreDecl(ND)) 111 return true; 112 113 if (RDO & IsLate) { 114 Instance.getDiagnostics().Report(diag::err_asm_invalid_type_in_input) 115 << "Generating Interface Stubs is not supported with " 116 "delayed template parsing."; 117 } else { 118 if (const auto *FD = dyn_cast<FunctionDecl>(ND)) 119 if (FD->isDependentContext()) 120 return true; 121 122 const bool IsWeak = (ND->hasAttr<WeakAttr>() || 123 ND->hasAttr<WeakRefAttr>() || ND->isWeakImported()); 124 125 Symbols.insert(std::make_pair( 126 ND, 127 MangledSymbol(getMangledNames(ParentDecl).front(), 128 // Type: 129 isa<VarDecl>(ND) ? llvm::ELF::STT_OBJECT 130 : llvm::ELF::STT_FUNC, 131 // Binding: 132 IsWeak ? llvm::ELF::STB_WEAK : llvm::ELF::STB_GLOBAL, 133 getMangledNames(ND)))); 134 } 135 return true; 136 } 137 138 void 139 HandleDecls(const llvm::iterator_range<DeclContext::decl_iterator> &Decls, 140 MangledSymbols &Symbols, int RDO) { 141 for (const auto *D : Decls) 142 HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO); 143 } 144 145 void HandleTemplateSpecializations(const FunctionTemplateDecl &FTD, 146 MangledSymbols &Symbols, int RDO) { 147 for (const auto *D : FTD.specializations()) 148 HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO); 149 } 150 151 void HandleTemplateSpecializations(const ClassTemplateDecl &CTD, 152 MangledSymbols &Symbols, int RDO) { 153 for (const auto *D : CTD.specializations()) 154 HandleNamedDecl(dyn_cast<NamedDecl>(D), Symbols, RDO); 155 } 156 157 bool HandleNamedDecl(const NamedDecl *ND, MangledSymbols &Symbols, int RDO) { 158 if (!ND) 159 return false; 160 161 switch (ND->getKind()) { 162 default: 163 break; 164 case Decl::Kind::Namespace: 165 HandleDecls(cast<NamespaceDecl>(ND)->decls(), Symbols, RDO); 166 return true; 167 case Decl::Kind::CXXRecord: 168 HandleDecls(cast<CXXRecordDecl>(ND)->decls(), Symbols, RDO); 169 return true; 170 case Decl::Kind::ClassTemplateSpecialization: 171 HandleDecls(cast<ClassTemplateSpecializationDecl>(ND)->decls(), Symbols, 172 RDO); 173 return true; 174 case Decl::Kind::ClassTemplate: 175 HandleTemplateSpecializations(*cast<ClassTemplateDecl>(ND), Symbols, RDO); 176 return true; 177 case Decl::Kind::FunctionTemplate: 178 HandleTemplateSpecializations(*cast<FunctionTemplateDecl>(ND), Symbols, 179 RDO); 180 return true; 181 case Decl::Kind::Record: 182 case Decl::Kind::Typedef: 183 case Decl::Kind::Enum: 184 case Decl::Kind::EnumConstant: 185 case Decl::Kind::TemplateTypeParm: 186 case Decl::Kind::NonTypeTemplateParm: 187 case Decl::Kind::CXXConversion: 188 case Decl::Kind::UnresolvedUsingValue: 189 case Decl::Kind::Using: 190 case Decl::Kind::UsingShadow: 191 case Decl::Kind::TypeAliasTemplate: 192 case Decl::Kind::TypeAlias: 193 case Decl::Kind::VarTemplate: 194 case Decl::Kind::VarTemplateSpecialization: 195 case Decl::Kind::UsingDirective: 196 case Decl::Kind::TemplateTemplateParm: 197 case Decl::Kind::ClassTemplatePartialSpecialization: 198 case Decl::Kind::IndirectField: 199 case Decl::Kind::ConstructorUsingShadow: 200 case Decl::Kind::CXXDeductionGuide: 201 case Decl::Kind::NamespaceAlias: 202 case Decl::Kind::UnresolvedUsingTypename: 203 return true; 204 case Decl::Kind::Var: { 205 // Bail on any VarDecl that either has no named symbol. 206 if (!ND->getIdentifier()) 207 return true; 208 const auto *VD = cast<VarDecl>(ND); 209 // Bail on any VarDecl that is a dependent or templated type. 210 if (VD->isTemplated() || VD->getType()->isDependentType()) 211 return true; 212 if (WriteNamedDecl(ND, Symbols, RDO)) 213 return true; 214 break; 215 } 216 case Decl::Kind::ParmVar: 217 case Decl::Kind::CXXMethod: 218 case Decl::Kind::CXXConstructor: 219 case Decl::Kind::CXXDestructor: 220 case Decl::Kind::Function: 221 case Decl::Kind::Field: 222 if (WriteNamedDecl(ND, Symbols, RDO)) 223 return true; 224 } 225 226 // While interface stubs are in the development stage, it's probably best to 227 // catch anything that's not a VarDecl or Template/FunctionDecl. 228 Instance.getDiagnostics().Report(diag::err_asm_invalid_type_in_input) 229 << "Expected a function or function template decl."; 230 return false; 231 } 232 233 public: 234 InterfaceStubFunctionsConsumer(CompilerInstance &Instance, StringRef InFile, 235 StringRef Format) 236 : Instance(Instance), InFile(InFile), Format(Format) {} 237 238 void HandleTranslationUnit(ASTContext &context) override { 239 struct Visitor : public RecursiveASTVisitor<Visitor> { 240 bool VisitNamedDecl(NamedDecl *ND) { 241 if (const auto *FD = dyn_cast<FunctionDecl>(ND)) 242 if (FD->isLateTemplateParsed()) { 243 LateParsedDecls.insert(FD); 244 return true; 245 } 246 247 if (const auto *VD = dyn_cast<ValueDecl>(ND)) { 248 ValueDecls.insert(VD); 249 return true; 250 } 251 252 NamedDecls.insert(ND); 253 return true; 254 } 255 256 std::set<const NamedDecl *> LateParsedDecls; 257 std::set<NamedDecl *> NamedDecls; 258 std::set<const ValueDecl *> ValueDecls; 259 } v; 260 261 v.TraverseDecl(context.getTranslationUnitDecl()); 262 263 MangledSymbols Symbols; 264 auto OS = Instance.createDefaultOutputFile(/*Binary=*/false, InFile, "ifs"); 265 if (!OS) 266 return; 267 268 if (Instance.getLangOpts().DelayedTemplateParsing) { 269 clang::Sema &S = Instance.getSema(); 270 for (const auto *FD : v.LateParsedDecls) { 271 clang::LateParsedTemplate &LPT = 272 *S.LateParsedTemplateMap.find(cast<FunctionDecl>(FD))->second; 273 S.LateTemplateParser(S.OpaqueParser, LPT); 274 HandleNamedDecl(FD, Symbols, (FromTU | IsLate)); 275 } 276 } 277 278 for (const NamedDecl *ND : v.ValueDecls) 279 HandleNamedDecl(ND, Symbols, FromTU); 280 for (const NamedDecl *ND : v.NamedDecls) 281 HandleNamedDecl(ND, Symbols, FromTU); 282 283 auto writeIfsV1 = [this](const llvm::Triple &T, 284 const MangledSymbols &Symbols, 285 const ASTContext &context, StringRef Format, 286 raw_ostream &OS) -> void { 287 OS << "--- !" << Format << "\n"; 288 OS << "IfsVersion: 1.0\n"; 289 OS << "Triple: " << T.str() << "\n"; 290 OS << "ObjectFileFormat: " 291 << "ELF" 292 << "\n"; // TODO: For now, just ELF. 293 OS << "Symbols:\n"; 294 for (const auto &E : Symbols) { 295 const MangledSymbol &Symbol = E.second; 296 for (auto Name : Symbol.Names) { 297 OS << " \"" 298 << (Symbol.ParentName.empty() || Instance.getLangOpts().CPlusPlus 299 ? "" 300 : (Symbol.ParentName + ".")) 301 << Name << "\" : { Type: "; 302 switch (Symbol.Type) { 303 default: 304 llvm_unreachable( 305 "clang -emit-interface-stubs: Unexpected symbol type."); 306 case llvm::ELF::STT_NOTYPE: 307 OS << "NoType"; 308 break; 309 case llvm::ELF::STT_OBJECT: { 310 auto VD = cast<ValueDecl>(E.first)->getType(); 311 OS << "Object, Size: " 312 << context.getTypeSizeInChars(VD).getQuantity(); 313 break; 314 } 315 case llvm::ELF::STT_FUNC: 316 OS << "Func"; 317 break; 318 } 319 if (Symbol.Binding == llvm::ELF::STB_WEAK) 320 OS << ", Weak: true"; 321 OS << " }\n"; 322 } 323 } 324 OS << "...\n"; 325 OS.flush(); 326 }; 327 328 assert(Format == "experimental-ifs-v1" && "Unexpected IFS Format."); 329 writeIfsV1(Instance.getTarget().getTriple(), Symbols, context, Format, *OS); 330 } 331 }; 332 } // namespace 333 334 std::unique_ptr<ASTConsumer> 335 GenerateInterfaceIfsExpV1Action::CreateASTConsumer(CompilerInstance &CI, 336 StringRef InFile) { 337 return std::make_unique<InterfaceStubFunctionsConsumer>( 338 CI, InFile, "experimental-ifs-v1"); 339 } 340