1 //===- ClangTidyPlugin.cpp - clang-tidy as a clang plugin -----------------===//
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 "../ClangTidy.h"
10 #include "../ClangTidyDiagnosticConsumer.h"
11 #include "../ClangTidyForceLinker.h"
12 #include "../ClangTidyModule.h"
13 #include "clang/Frontend/CompilerInstance.h"
14 #include "clang/Frontend/FrontendPluginRegistry.h"
15 #include "clang/Frontend/MultiplexConsumer.h"
16 
17 namespace clang {
18 namespace tidy {
19 
20 /// The core clang tidy plugin action. This just provides the AST consumer and
21 /// command line flag parsing for using clang-tidy as a clang plugin.
22 class ClangTidyPluginAction : public PluginASTAction {
23   /// Wrapper to grant the context and diagnostics engine the same lifetime as
24   /// the action.
25   /// We use MultiplexConsumer to avoid writing out all the forwarding methods.
26   class WrapConsumer : public MultiplexConsumer {
27     std::unique_ptr<ClangTidyContext> Context;
28     std::unique_ptr<DiagnosticsEngine> DiagEngine;
29 
30   public:
WrapConsumer(std::unique_ptr<ClangTidyContext> Context,std::unique_ptr<DiagnosticsEngine> DiagEngine,std::vector<std::unique_ptr<ASTConsumer>> Consumer)31     WrapConsumer(std::unique_ptr<ClangTidyContext> Context,
32                  std::unique_ptr<DiagnosticsEngine> DiagEngine,
33                  std::vector<std::unique_ptr<ASTConsumer>> Consumer)
34         : MultiplexConsumer(std::move(Consumer)), Context(std::move(Context)),
35           DiagEngine(std::move(DiagEngine)) {}
36   };
37 
38 public:
CreateASTConsumer(CompilerInstance & Compiler,StringRef File)39   std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &Compiler,
40                                                  StringRef File) override {
41     // Create and set diagnostics engine
42     auto ExternalDiagEngine = &Compiler.getDiagnostics();
43     auto DiagConsumer =
44         new ClangTidyDiagnosticConsumer(*Context, ExternalDiagEngine);
45     auto DiagEngine = std::make_unique<DiagnosticsEngine>(
46         new DiagnosticIDs, new DiagnosticOptions, DiagConsumer);
47     Context->setDiagnosticsEngine(DiagEngine.get());
48 
49     // Create the AST consumer.
50     ClangTidyASTConsumerFactory Factory(*Context);
51     std::vector<std::unique_ptr<ASTConsumer>> Vec;
52     Vec.push_back(Factory.CreateASTConsumer(Compiler, File));
53 
54     return std::make_unique<WrapConsumer>(
55         std::move(Context), std::move(DiagEngine), std::move(Vec));
56   }
57 
ParseArgs(const CompilerInstance &,const std::vector<std::string> & Args)58   bool ParseArgs(const CompilerInstance &,
59                  const std::vector<std::string> &Args) override {
60     ClangTidyGlobalOptions GlobalOptions;
61     ClangTidyOptions DefaultOptions;
62     ClangTidyOptions OverrideOptions;
63 
64     // Parse the extra command line args.
65     // FIXME: This is very limited at the moment.
66     for (StringRef Arg : Args)
67       if (Arg.startswith("-checks="))
68         OverrideOptions.Checks = std::string(Arg.substr(strlen("-checks=")));
69 
70     auto Options = std::make_unique<FileOptionsProvider>(
71         GlobalOptions, DefaultOptions, OverrideOptions);
72     Context = std::make_unique<ClangTidyContext>(std::move(Options));
73     return true;
74   }
75 
76 private:
77   std::unique_ptr<ClangTidyContext> Context;
78 };
79 } // namespace tidy
80 } // namespace clang
81 
82 // This anchor is used to force the linker to link in the generated object file
83 // and thus register the clang-tidy plugin.
84 volatile int ClangTidyPluginAnchorSource = 0;
85 
86 static clang::FrontendPluginRegistry::Add<clang::tidy::ClangTidyPluginAction>
87     X("clang-tidy", "clang-tidy");
88