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 
89   static cl::opt<std::string> BuildPath("p", cl::desc("Build path"),
90                                         cl::Optional, cl::cat(Category));
91 
92   static cl::list<std::string> SourcePaths(
93       cl::Positional, cl::desc("<source0> [... <sourceN>]"), OccurrencesFlag,
94       cl::cat(Category));
95 
96   static cl::list<std::string> ArgsAfter(
97       "extra-arg",
98       cl::desc("Additional argument to append to the compiler command line"),
99       cl::cat(Category));
100 
101   static cl::list<std::string> ArgsBefore(
102       "extra-arg-before",
103       cl::desc("Additional argument to prepend to the compiler command line"),
104       cl::cat(Category));
105 
106   cl::HideUnrelatedOptions(Category);
107 
108   std::string ErrorMessage;
109   Compilations =
110       FixedCompilationDatabase::loadFromCommandLine(argc, argv, ErrorMessage);
111   if (!Compilations && !ErrorMessage.empty())
112     llvm::errs() << ErrorMessage;
113   cl::ParseCommandLineOptions(argc, argv, Overview);
114   cl::PrintOptionValues();
115 
116   SourcePathList = SourcePaths;
117   if ((OccurrencesFlag == cl::ZeroOrMore || OccurrencesFlag == cl::Optional) &&
118       SourcePathList.empty())
119     return;
120   if (!Compilations) {
121     if (!BuildPath.empty()) {
122       Compilations =
123           CompilationDatabase::autoDetectFromDirectory(BuildPath, ErrorMessage);
124     } else {
125       Compilations = CompilationDatabase::autoDetectFromSource(SourcePaths[0],
126                                                                ErrorMessage);
127     }
128     if (!Compilations) {
129       llvm::errs() << "Error while trying to load a compilation database:\n"
130                    << ErrorMessage << "Running without flags.\n";
131       Compilations.reset(
132           new FixedCompilationDatabase(".", std::vector<std::string>()));
133     }
134   }
135   auto AdjustingCompilations =
136       llvm::make_unique<ArgumentsAdjustingCompilations>(
137           std::move(Compilations));
138   AdjustingCompilations->appendArgumentsAdjuster(
139       getInsertArgumentAdjuster(ArgsBefore, ArgumentInsertPosition::BEGIN));
140   AdjustingCompilations->appendArgumentsAdjuster(
141       getInsertArgumentAdjuster(ArgsAfter, ArgumentInsertPosition::END));
142   Compilations = std::move(AdjustingCompilations);
143 }
144