//===--- tools/clang-check/ClangCheck.cpp - Clang check tool --------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

//  This file implements a clang-check tool that runs clang based on the info

//  stored in a compilation database.

//

//  This tool uses the Clang Tooling infrastructure, see

//    http://clang.llvm.org/docs/HowToSetupToolingForLLVM.html

//  for details on setting it up with LLVM source tree.

//

//===----------------------------------------------------------------------===//

#include "clang/AST/ASTConsumer.h"

#include "clang/CodeGen/ObjectFilePCHContainerOperations.h"

#include "clang/Driver/Options.h"

#include "clang/Frontend/ASTConsumers.h"

#include "clang/Frontend/CompilerInstance.h"

#include "clang/Rewrite/Frontend/FixItRewriter.h"

#include "clang/Rewrite/Frontend/FrontendActions.h"

#include "clang/StaticAnalyzer/Frontend/FrontendActions.h"

#include "clang/Tooling/CommonOptionsParser.h"

#include "clang/Tooling/Tooling.h"

#include "llvm/ADT/STLExtras.h"

#include "llvm/Option/OptTable.h"

#include "llvm/Support/Path.h"

#include "llvm/Support/Signals.h"

#include "llvm/Support/TargetSelect.h"

using namespace clang::driver;

using namespace clang::tooling;

using namespace llvm;

static cl::extrahelp CommonHelp(CommonOptionsParser::HelpMessage);

static cl::extrahelp MoreHelp(

    "\tFor example, to run clang-check on all files in a subtree of the\n"

    "\tsource tree, use:\n"

    "\n"

    "\t  find path/in/subtree -name '*.cpp'|xargs clang-check\n"

    "\n"

    "\tor using a specific build path:\n"

    "\n"

    "\t  find path/in/subtree -name '*.cpp'|xargs clang-check -p build/path\n"

    "\n"

    "\tNote, that path/in/subtree and current directory should follow the\n"

    "\trules described above.\n"

    "\n"

);

static cl::OptionCategory ClangCheckCategory("clang-check options");

static const opt::OptTable &Options = getDriverOptTable();

static cl::opt<bool>

    ASTDump("ast-dump",

            cl::desc(Options.getOptionHelpText(options::OPT_ast_dump)),

            cl::cat(ClangCheckCategory));

static cl::opt<bool>

    ASTList("ast-list",

            cl::desc(Options.getOptionHelpText(options::OPT_ast_list)),

            cl::cat(ClangCheckCategory));

static cl::opt<bool>

    ASTPrint("ast-print",

             cl::desc(Options.getOptionHelpText(options::OPT_ast_print)),

             cl::cat(ClangCheckCategory));

static cl::opt<std::string> ASTDumpFilter(

    "ast-dump-filter",

    cl::desc(Options.getOptionHelpText(options::OPT_ast_dump_filter)),

    cl::cat(ClangCheckCategory));

static cl::opt<bool>

    Analyze("analyze",

            cl::desc(Options.getOptionHelpText(options::OPT_analyze)),

            cl::cat(ClangCheckCategory));

static cl::opt<bool>

    Fixit("fixit", cl::desc(Options.getOptionHelpText(options::OPT_fixit)),

          cl::cat(ClangCheckCategory));

static cl::opt<bool> FixWhatYouCan(

    "fix-what-you-can",

    cl::desc(Options.getOptionHelpText(options::OPT_fix_what_you_can)),

    cl::cat(ClangCheckCategory));

namespace {

// FIXME: Move FixItRewriteInPlace from lib/Rewrite/Frontend/FrontendActions.cpp

// into a header file and reuse that.

class FixItOptions : public clang::FixItOptions {

public:

  FixItOptions() {

    FixWhatYouCan = ::FixWhatYouCan;

  }

  std::string RewriteFilename(const std::string& filename, int &fd) override {

    // We don't need to do permission checking here since clang will diagnose

    // any I/O errors itself.

    fd = -1;  // No file descriptor for file.

    return filename;

  }

};

/// Subclasses \c clang::FixItRewriter to not count fixed errors/warnings

/// in the final error counts.

///

/// This has the side-effect that clang-check -fixit exits with code 0 on

/// successfully fixing all errors.

class FixItRewriter : public clang::FixItRewriter {

public:

  FixItRewriter(clang::DiagnosticsEngine& Diags,

                clang::SourceManager& SourceMgr,

                const clang::LangOptions& LangOpts,

                clang::FixItOptions* FixItOpts)

      : clang::FixItRewriter(Diags, SourceMgr, LangOpts, FixItOpts) {

  }

  bool IncludeInDiagnosticCounts() const override { return false; }

};

/// Subclasses \c clang::FixItAction so that we can install the custom

/// \c FixItRewriter.

class ClangCheckFixItAction : public clang::FixItAction {

public:

  bool BeginSourceFileAction(clang::CompilerInstance& CI) override {

    FixItOpts.reset(new FixItOptions);

    Rewriter.reset(new FixItRewriter(CI.getDiagnostics(), CI.getSourceManager(),

                                     CI.getLangOpts(), FixItOpts.get()));

    return true;

  }

};

class ClangCheckActionFactory {

public:

  std::unique_ptr<clang::ASTConsumer> newASTConsumer() {

    if (ASTList)

      return clang::CreateASTDeclNodeLister();

    if (ASTDump)

      return clang::CreateASTDumper(nullptr /*Dump to stdout.*/, ASTDumpFilter,

                                    /*DumpDecls=*/true,

                                    /*Deserialize=*/false,

                                    /*DumpLookups=*/false,

                                    /*DumpDeclTypes=*/false,

                                    clang::ADOF_Default);

    if (ASTPrint)

      return clang::CreateASTPrinter(nullptr, ASTDumpFilter);

    return std::make_unique<clang::ASTConsumer>();

  }

};

} // namespace

int main(int argc, const char **argv) {

  llvm::sys::PrintStackTraceOnErrorSignal(argv[0]);

  // Initialize targets for clang module support.

  llvm::InitializeAllTargets();

  llvm::InitializeAllTargetMCs();

  llvm::InitializeAllAsmPrinters();

  llvm::InitializeAllAsmParsers();

  CommonOptionsParser OptionsParser(argc, argv, ClangCheckCategory);

  ClangTool Tool(OptionsParser.getCompilations(),

                 OptionsParser.getSourcePathList());

  // Clear adjusters because -fsyntax-only is inserted by the default chain.

  Tool.clearArgumentsAdjusters();

  Tool.appendArgumentsAdjuster(getClangStripOutputAdjuster());

  Tool.appendArgumentsAdjuster(getClangStripDependencyFileAdjuster());

  // Running the analyzer requires --analyze. Other modes can work with the

  // -fsyntax-only option.

  Tool.appendArgumentsAdjuster(getInsertArgumentAdjuster(

      Analyze ? 
"--analyze"4
 : "-fsyntax-only", ArgumentInsertPosition::BEGIN));

  ClangCheckActionFactory CheckFactory;

  std::unique_ptr<FrontendActionFactory> FrontendFactory;

  // Choose the correct factory based on the selected mode.

  if (Analyze)

    FrontendFactory = newFrontendActionFactory<clang::ento::AnalysisAction>();

  else if (Fixit)

    FrontendFactory = newFrontendActionFactory<ClangCheckFixItAction>();

  else

    FrontendFactory = newFrontendActionFactory(&CheckFactory);

  return Tool.run(FrontendFactory.get());

}