1 //===- PrintFunctionNames.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 // Example clang plugin which simply prints the names of all the top-level decls 10 // in the input file. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "clang/Frontend/FrontendPluginRegistry.h" 15 #include "clang/AST/AST.h" 16 #include "clang/AST/ASTConsumer.h" 17 #include "clang/AST/RecursiveASTVisitor.h" 18 #include "clang/Frontend/CompilerInstance.h" 19 #include "clang/Sema/Sema.h" 20 #include "llvm/Support/raw_ostream.h" 21 using namespace clang; 22 23 namespace { 24 25 class PrintFunctionsConsumer : public ASTConsumer { 26 CompilerInstance &Instance; 27 std::set<std::string> ParsedTemplates; 28 29 public: PrintFunctionsConsumer(CompilerInstance & Instance,std::set<std::string> ParsedTemplates)30 PrintFunctionsConsumer(CompilerInstance &Instance, 31 std::set<std::string> ParsedTemplates) 32 : Instance(Instance), ParsedTemplates(ParsedTemplates) {} 33 HandleTopLevelDecl(DeclGroupRef DG)34 bool HandleTopLevelDecl(DeclGroupRef DG) override { 35 for (DeclGroupRef::iterator i = DG.begin(), e = DG.end(); i != e; ++i) { 36 const Decl *D = *i; 37 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 38 llvm::errs() << "top-level-decl: \"" << ND->getNameAsString() << "\"\n"; 39 } 40 41 return true; 42 } 43 HandleTranslationUnit(ASTContext & context)44 void HandleTranslationUnit(ASTContext& context) override { 45 if (!Instance.getLangOpts().DelayedTemplateParsing) 46 return; 47 48 // This demonstrates how to force instantiation of some templates in 49 // -fdelayed-template-parsing mode. (Note: Doing this unconditionally for 50 // all templates is similar to not using -fdelayed-template-parsig in the 51 // first place.) 52 // The advantage of doing this in HandleTranslationUnit() is that all 53 // codegen (when using -add-plugin) is completely finished and this can't 54 // affect the compiler output. 55 struct Visitor : public RecursiveASTVisitor<Visitor> { 56 const std::set<std::string> &ParsedTemplates; 57 Visitor(const std::set<std::string> &ParsedTemplates) 58 : ParsedTemplates(ParsedTemplates) {} 59 bool VisitFunctionDecl(FunctionDecl *FD) { 60 if (FD->isLateTemplateParsed() && 61 ParsedTemplates.count(FD->getNameAsString())) 62 LateParsedDecls.insert(FD); 63 return true; 64 } 65 66 std::set<FunctionDecl*> LateParsedDecls; 67 } v(ParsedTemplates); 68 v.TraverseDecl(context.getTranslationUnitDecl()); 69 clang::Sema &sema = Instance.getSema(); 70 for (const FunctionDecl *FD : v.LateParsedDecls) { 71 clang::LateParsedTemplate &LPT = 72 *sema.LateParsedTemplateMap.find(FD)->second; 73 sema.LateTemplateParser(sema.OpaqueParser, LPT); 74 llvm::errs() << "late-parsed-decl: \"" << FD->getNameAsString() << "\"\n"; 75 } 76 } 77 }; 78 79 class PrintFunctionNamesAction : public PluginASTAction { 80 std::set<std::string> ParsedTemplates; 81 protected: CreateASTConsumer(CompilerInstance & CI,llvm::StringRef)82 std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI, 83 llvm::StringRef) override { 84 return std::make_unique<PrintFunctionsConsumer>(CI, ParsedTemplates); 85 } 86 ParseArgs(const CompilerInstance & CI,const std::vector<std::string> & args)87 bool ParseArgs(const CompilerInstance &CI, 88 const std::vector<std::string> &args) override { 89 for (unsigned i = 0, e = args.size(); i != e; ++i) { 90 llvm::errs() << "PrintFunctionNames arg = " << args[i] << "\n"; 91 92 // Example error handling. 93 DiagnosticsEngine &D = CI.getDiagnostics(); 94 if (args[i] == "-an-error") { 95 unsigned DiagID = D.getCustomDiagID(DiagnosticsEngine::Error, 96 "invalid argument '%0'"); 97 D.Report(DiagID) << args[i]; 98 return false; 99 } else if (args[i] == "-parse-template") { 100 if (i + 1 >= e) { 101 D.Report(D.getCustomDiagID(DiagnosticsEngine::Error, 102 "missing -parse-template argument")); 103 return false; 104 } 105 ++i; 106 ParsedTemplates.insert(args[i]); 107 } 108 } 109 if (!args.empty() && args[0] == "help") 110 PrintHelp(llvm::errs()); 111 112 return true; 113 } PrintHelp(llvm::raw_ostream & ros)114 void PrintHelp(llvm::raw_ostream& ros) { 115 ros << "Help for PrintFunctionNames plugin goes here\n"; 116 } 117 118 }; 119 120 } 121 122 static FrontendPluginRegistry::Add<PrintFunctionNamesAction> 123 X("print-fns", "print function names"); 124