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      1 //===--- CommonOptionsParser.cpp - common options for clang tools ---------===//
      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 //  This file implements the CommonOptionsParser class used to parse common
     11 //  command-line options for clang tools, so that they can be run as separate
     12 //  command-line applications with a consistent common interface for handling
     13 //  compilation database and input files.
     14 //
     15 //  It provides a common subset of command-line options, common algorithm
     16 //  for locating a compilation database and source files, and help messages
     17 //  for the basic command-line interface.
     18 //
     19 //  It creates a CompilationDatabase and reads common command-line options.
     20 //
     21 //  This class uses the Clang Tooling infrastructure, see
     22 //    http://clang.llvm.org/docs/HowToSetupToolingForLLVM.html
     23 //  for details on setting it up with LLVM source tree.
     24 //
     25 //===----------------------------------------------------------------------===//
     26 
     27 #include "llvm/Support/CommandLine.h"
     28 #include "clang/Tooling/ArgumentsAdjusters.h"
     29 #include "clang/Tooling/CommonOptionsParser.h"
     30 #include "clang/Tooling/Tooling.h"
     31 
     32 using namespace clang::tooling;
     33 using namespace llvm;
     34 
     35 const char *const CommonOptionsParser::HelpMessage =
     36     "\n"
     37     "-p <build-path> is used to read a compile command database.\n"
     38     "\n"
     39     "\tFor example, it can be a CMake build directory in which a file named\n"
     40     "\tcompile_commands.json exists (use -DCMAKE_EXPORT_COMPILE_COMMANDS=ON\n"
     41     "\tCMake option to get this output). When no build path is specified,\n"
     42     "\ta search for compile_commands.json will be attempted through all\n"
     43     "\tparent paths of the first input file . See:\n"
     44     "\thttp://clang.llvm.org/docs/HowToSetupToolingForLLVM.html for an\n"
     45     "\texample of setting up Clang Tooling on a source tree.\n"
     46     "\n"
     47     "<source0> ... specify the paths of source files. These paths are\n"
     48     "\tlooked up in the compile command database. If the path of a file is\n"
     49     "\tabsolute, it needs to point into CMake's source tree. If the path is\n"
     50     "\trelative, the current working directory needs to be in the CMake\n"
     51     "\tsource tree and the file must be in a subdirectory of the current\n"
     52     "\tworking directory. \"./\" prefixes in the relative files will be\n"
     53     "\tautomatically removed, but the rest of a relative path must be a\n"
     54     "\tsuffix of a path in the compile command database.\n"
     55     "\n";
     56 
     57 namespace {
     58 class ArgumentsAdjustingCompilations : public CompilationDatabase {
     59 public:
     60   ArgumentsAdjustingCompilations(
     61       std::unique_ptr<CompilationDatabase> Compilations)
     62       : Compilations(std::move(Compilations)) {}
     63 
     64   void appendArgumentsAdjuster(ArgumentsAdjuster Adjuster) {
     65     Adjusters.push_back(Adjuster);
     66   }
     67 
     68   std::vector<CompileCommand>
     69   getCompileCommands(StringRef FilePath) const override {
     70     return adjustCommands(Compilations->getCompileCommands(FilePath));
     71   }
     72 
     73   std::vector<std::string> getAllFiles() const override {
     74     return Compilations->getAllFiles();
     75   }
     76 
     77   std::vector<CompileCommand> getAllCompileCommands() const override {
     78     return adjustCommands(Compilations->getAllCompileCommands());
     79   }
     80 
     81 private:
     82   std::unique_ptr<CompilationDatabase> Compilations;
     83   std::vector<ArgumentsAdjuster> Adjusters;
     84 
     85   std::vector<CompileCommand>
     86   adjustCommands(std::vector<CompileCommand> Commands) const {
     87     for (CompileCommand &Command : Commands)
     88       for (const auto &Adjuster : Adjusters)
     89         Command.CommandLine = Adjuster(Command.CommandLine, Command.Filename);
     90     return Commands;
     91   }
     92 };
     93 } // namespace
     94 
     95 CommonOptionsParser::CommonOptionsParser(
     96     int &argc, const char **argv, cl::OptionCategory &Category,
     97     llvm::cl::NumOccurrencesFlag OccurrencesFlag, const char *Overview) {
     98   static cl::opt<bool> Help("h", cl::desc("Alias for -help"), cl::Hidden);
     99 
    100   static cl::opt<std::string> BuildPath("p", cl::desc("Build path"),
    101                                         cl::Optional, cl::cat(Category));
    102 
    103   static cl::list<std::string> SourcePaths(
    104       cl::Positional, cl::desc("<source0> [... <sourceN>]"), OccurrencesFlag,
    105       cl::cat(Category));
    106 
    107   static cl::list<std::string> ArgsAfter(
    108       "extra-arg",
    109       cl::desc("Additional argument to append to the compiler command line"),
    110       cl::cat(Category));
    111 
    112   static cl::list<std::string> ArgsBefore(
    113       "extra-arg-before",
    114       cl::desc("Additional argument to prepend to the compiler command line"),
    115       cl::cat(Category));
    116 
    117   cl::HideUnrelatedOptions(Category);
    118 
    119   Compilations.reset(FixedCompilationDatabase::loadFromCommandLine(argc, argv));
    120   cl::ParseCommandLineOptions(argc, argv, Overview);
    121   SourcePathList = SourcePaths;
    122   if ((OccurrencesFlag == cl::ZeroOrMore || OccurrencesFlag == cl::Optional) &&
    123       SourcePathList.empty())
    124     return;
    125   if (!Compilations) {
    126     std::string ErrorMessage;
    127     if (!BuildPath.empty()) {
    128       Compilations =
    129           CompilationDatabase::autoDetectFromDirectory(BuildPath, ErrorMessage);
    130     } else {
    131       Compilations = CompilationDatabase::autoDetectFromSource(SourcePaths[0],
    132                                                                ErrorMessage);
    133     }
    134     if (!Compilations) {
    135       llvm::errs() << "Error while trying to load a compilation database:\n"
    136                    << ErrorMessage << "Running without flags.\n";
    137       Compilations.reset(
    138           new FixedCompilationDatabase(".", std::vector<std::string>()));
    139     }
    140   }
    141   auto AdjustingCompilations =
    142       llvm::make_unique<ArgumentsAdjustingCompilations>(
    143           std::move(Compilations));
    144   AdjustingCompilations->appendArgumentsAdjuster(
    145       getInsertArgumentAdjuster(ArgsBefore, ArgumentInsertPosition::BEGIN));
    146   AdjustingCompilations->appendArgumentsAdjuster(
    147       getInsertArgumentAdjuster(ArgsAfter, ArgumentInsertPosition::END));
    148   Compilations = std::move(AdjustingCompilations);
    149 }
    150