clang-tools-extra/tool-template/ToolTemplate.cpp

   1 //===---- tools/extra/ToolTemplate.cpp - Template for refactoring tool ----===//
   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 //  This file implements an empty refactoring tool using the clang tooling.
  10 //  The goal is to lower the "barrier to entry" for writing refactoring tools.
  11 //
  12 //  Usage:
  13 //  tool-template <cmake-output-dir> <file1> <file2> ...
  14 //
  15 //  Where <cmake-output-dir> is a CMake build directory in which a file named
  16 //  compile_commands.json exists (enable -DCMAKE_EXPORT_COMPILE_COMMANDS in
  17 //  CMake to get this output).
  18 //
  19 //  <file1> ... specify the paths of files in the CMake source tree. This path
  20 //  is looked up in the compile command database. If the path of a file is
  21 //  absolute, it needs to point into CMake's source tree. If the path is
  22 //  relative, the current working directory needs to be in the CMake source
  23 //  tree and the file must be in a subdirectory of the current working
  24 //  directory. "./" prefixes in the relative files will be automatically
  25 //  removed, but the rest of a relative path must be a suffix of a path in
  26 //  the compile command line database.
  27 //
  28 //  For example, to use tool-template on all files in a subtree of the
  29 //  source tree, use:
  30 //
  31 //    /path/in/subtree $ find . -name '*.cpp'|
  32 //        xargs tool-template /path/to/build
  33 //
  34 //===----------------------------------------------------------------------===//
  35
  36 #include "clang/ASTMatchers/ASTMatchFinder.h"
  37 #include "clang/ASTMatchers/ASTMatchers.h"
  38 #include "clang/Basic/SourceManager.h"
  39 #include "clang/Frontend/FrontendActions.h"
  40 #include "clang/Lex/Lexer.h"
  41 #include "clang/Tooling/CommonOptionsParser.h"
  42 #include "clang/Tooling/Execution.h"
  43 #include "clang/Tooling/Refactoring.h"
  44 #include "clang/Tooling/Refactoring/AtomicChange.h"
  45 #include "clang/Tooling/Tooling.h"
  46 #include "llvm/Support/CommandLine.h"
  47 #include "llvm/Support/MemoryBuffer.h"
  48 #include "llvm/Support/Signals.h"
  49
  50 using namespace clang;
  51 using namespace clang::ast_matchers;
  52 using namespace clang::tooling;
  53 using namespace llvm;
  54
  55 namespace {
  56 class ToolTemplateCallback : public MatchFinder::MatchCallback {
  57 public:
  58   ToolTemplateCallback(ExecutionContext &Context) : Context(Context) {}
  59
  60   void run(const MatchFinder::MatchResult &Result) override {
  61     // TODO: This routine will get called for each thing that the matchers
  62     // find.
  63     // At this point, you can examine the match, and do whatever you want,
  64     // including replacing the matched text with other text
  65     auto *D = Result.Nodes.getNodeAs<NamedDecl>("decl");
  66     assert(D);
  67     // Use AtomicChange to get a key.
  68     if (D->getBeginLoc().isValid()) {
  69       AtomicChange Change(*Result.SourceManager, D->getBeginLoc());
  70       Context.reportResult(Change.getKey(), D->getQualifiedNameAsString());
  71     }
  72   }
  73
  74   void onStartOfTranslationUnit() override {
  75     Context.reportResult("START", "Start of TU.");
  76   }
  77   void onEndOfTranslationUnit() override {
  78     Context.reportResult("END", "End of TU.");
  79   }
  80
  81 private:
  82   ExecutionContext &Context;
  83 };
  84 } // end anonymous namespace
  85
  86 // Set up the command line options
  87 static cl::extrahelp CommonHelp(CommonOptionsParser::HelpMessage);
  88 static cl::OptionCategory ToolTemplateCategory("tool-template options");
  89
  90 int main(int argc, const char **argv) {
  91   llvm::sys::PrintStackTraceOnErrorSignal(argv[0]);
  92
  93   auto Executor = clang::tooling::createExecutorFromCommandLineArgs(
  94       argc, argv, ToolTemplateCategory);
  95
  96   if (!Executor) {
  97     llvm::errs() << llvm::toString(Executor.takeError()) << "\n";
  98     return 1;
  99   }
 100
 101   ast_matchers::MatchFinder Finder;
 102   ToolTemplateCallback Callback(*Executor->get()->getExecutionContext());
 103
 104   // TODO: Put your matchers here.
 105   // Use Finder.addMatcher(...) to define the patterns in the AST that you
 106   // want to match against. You are not limited to just one matcher!
 107   //
 108   // This is a sample matcher:
 109   Finder.addMatcher(
 110       namedDecl(cxxRecordDecl(), isExpansionInMainFile()).bind("decl"),
 111       &Callback);
 112
 113   auto Err = Executor->get()->execute(newFrontendActionFactory(&Finder));
 114   if (Err) {
 115     llvm::errs() << llvm::toString(std::move(Err)) << "\n";
 116   }
 117   Executor->get()->getToolResults()->forEachResult(
 118       [](llvm::StringRef key, llvm::StringRef value) {
 119         llvm::errs() << "----" << key.str() << "\n" << value.str() << "\n";
 120       });
 121 }