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 }
122