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 "clang/Tooling/CommonOptionsParser.h"
28 #include "clang/Tooling/Tooling.h"
29 #include "llvm/Support/CommandLine.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 llvm::Error CommonOptionsParser::init(
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::ResetAllOptionOccurrences();
109 
110   cl::HideUnrelatedOptions(Category);
111 
112   std::string ErrorMessage;
113   Compilations =
114       FixedCompilationDatabase::loadFromCommandLine(argc, argv, ErrorMessage);
115   if (!ErrorMessage.empty())
116     ErrorMessage.append("\n");
117   llvm::raw_string_ostream OS(ErrorMessage);
118   // Stop initializing if command-line option parsing failed.
119   if (!cl::ParseCommandLineOptions(argc, argv, Overview, &OS)) {
120     OS.flush();
121     return llvm::make_error<llvm::StringError>("[CommonOptionsParser]: " +
122                                                    ErrorMessage,
123                                                llvm::inconvertibleErrorCode());
124   }
125 
126   cl::PrintOptionValues();
127 
128   SourcePathList = SourcePaths;
129   if ((OccurrencesFlag == cl::ZeroOrMore || OccurrencesFlag == cl::Optional) &&
130       SourcePathList.empty())
131     return llvm::Error::success();
132   if (!Compilations) {
133     if (!BuildPath.empty()) {
134       Compilations =
135           CompilationDatabase::autoDetectFromDirectory(BuildPath, ErrorMessage);
136     } else {
137       Compilations = CompilationDatabase::autoDetectFromSource(SourcePaths[0],
138                                                                ErrorMessage);
139     }
140     if (!Compilations) {
141       llvm::errs() << "Error while trying to load a compilation database:\n"
142                    << ErrorMessage << "Running without flags.\n";
143       Compilations.reset(
144           new FixedCompilationDatabase(".", std::vector<std::string>()));
145     }
146   }
147   auto AdjustingCompilations =
148       llvm::make_unique<ArgumentsAdjustingCompilations>(
149           std::move(Compilations));
150   AdjustingCompilations->appendArgumentsAdjuster(
151       getInsertArgumentAdjuster(ArgsBefore, ArgumentInsertPosition::BEGIN));
152   AdjustingCompilations->appendArgumentsAdjuster(
153       getInsertArgumentAdjuster(ArgsAfter, ArgumentInsertPosition::END));
154   Compilations = std::move(AdjustingCompilations);
155   return llvm::Error::success();
156 }
157 
158 llvm::Expected<CommonOptionsParser> CommonOptionsParser::create(
159     int &argc, const char **argv, llvm::cl::OptionCategory &Category,
160     llvm::cl::NumOccurrencesFlag OccurrencesFlag, const char *Overview) {
161   CommonOptionsParser Parser;
162   llvm::Error Err =
163       Parser.init(argc, argv, Category, OccurrencesFlag, Overview);
164   if (Err)
165     return std::move(Err);
166   return std::move(Parser);
167 }
168 
169 CommonOptionsParser::CommonOptionsParser(
170     int &argc, const char **argv, cl::OptionCategory &Category,
171     llvm::cl::NumOccurrencesFlag OccurrencesFlag, const char *Overview) {
172   llvm::Error Err = init(argc, argv, Category, OccurrencesFlag, Overview);
173   if (Err) {
174     llvm::report_fatal_error(
175         "CommonOptionsParser: failed to parse command-line arguments. " +
176         llvm::toString(std::move(Err)));
177   }
178 }
179