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