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