1 //===--- CommonOptionsParser.cpp - common options for clang tools ---------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //  This file implements the CommonOptionsParser class used to parse common
10 //  command-line options for clang tools, so that they can be run as separate
11 //  command-line applications with a consistent common interface for handling
12 //  compilation database and input files.
13 //
14 //  It provides a common subset of command-line options, common algorithm
15 //  for locating a compilation database and source files, and help messages
16 //  for the basic command-line interface.
17 //
18 //  It creates a CompilationDatabase and reads common command-line options.
19 //
20 //  This class uses the Clang Tooling infrastructure, see
21 //    http://clang.llvm.org/docs/HowToSetupToolingForLLVM.html
22 //  for details on setting it up with LLVM source tree.
23 //
24 //===----------------------------------------------------------------------===//
25 
26 #include "clang/Tooling/CommonOptionsParser.h"
27 #include "clang/Tooling/Tooling.h"
28 #include "llvm/Support/CommandLine.h"
29 
30 using namespace clang::tooling;
31 using namespace llvm;
32 
33 const char *const CommonOptionsParser::HelpMessage =
34     "\n"
35     "-p <build-path> is used to read a compile command database.\n"
36     "\n"
37     "\tFor example, it can be a CMake build directory in which a file named\n"
38     "\tcompile_commands.json exists (use -DCMAKE_EXPORT_COMPILE_COMMANDS=ON\n"
39     "\tCMake option to get this output). When no build path is specified,\n"
40     "\ta search for compile_commands.json will be attempted through all\n"
41     "\tparent paths of the first input file . See:\n"
42     "\thttps://clang.llvm.org/docs/HowToSetupToolingForLLVM.html for an\n"
43     "\texample of setting up Clang Tooling on a source tree.\n"
44     "\n"
45     "<source0> ... specify the paths of source files. These paths are\n"
46     "\tlooked up in the compile command database. If the path of a file is\n"
47     "\tabsolute, it needs to point into CMake's source tree. If the path is\n"
48     "\trelative, the current working directory needs to be in the CMake\n"
49     "\tsource tree and the file must be in a subdirectory of the current\n"
50     "\tworking directory. \"./\" prefixes in the relative files will be\n"
51     "\tautomatically removed, but the rest of a relative path must be a\n"
52     "\tsuffix of a path in the compile command database.\n"
53     "\n";
54 
appendArgumentsAdjuster(ArgumentsAdjuster Adjuster)55 void ArgumentsAdjustingCompilations::appendArgumentsAdjuster(
56     ArgumentsAdjuster Adjuster) {
57   Adjusters.push_back(std::move(Adjuster));
58 }
59 
getCompileCommands(StringRef FilePath) const60 std::vector<CompileCommand> ArgumentsAdjustingCompilations::getCompileCommands(
61     StringRef FilePath) const {
62   return adjustCommands(Compilations->getCompileCommands(FilePath));
63 }
64 
65 std::vector<std::string>
getAllFiles() const66 ArgumentsAdjustingCompilations::getAllFiles() const {
67   return Compilations->getAllFiles();
68 }
69 
70 std::vector<CompileCommand>
getAllCompileCommands() const71 ArgumentsAdjustingCompilations::getAllCompileCommands() const {
72   return adjustCommands(Compilations->getAllCompileCommands());
73 }
74 
adjustCommands(std::vector<CompileCommand> Commands) const75 std::vector<CompileCommand> ArgumentsAdjustingCompilations::adjustCommands(
76     std::vector<CompileCommand> Commands) const {
77   for (CompileCommand &Command : Commands)
78     for (const auto &Adjuster : Adjusters)
79       Command.CommandLine = Adjuster(Command.CommandLine, Command.Filename);
80   return Commands;
81 }
82 
init(int & argc,const char ** argv,cl::OptionCategory & Category,llvm::cl::NumOccurrencesFlag OccurrencesFlag,const char * Overview)83 llvm::Error CommonOptionsParser::init(
84     int &argc, const char **argv, cl::OptionCategory &Category,
85     llvm::cl::NumOccurrencesFlag OccurrencesFlag, const char *Overview) {
86 
87   static cl::opt<std::string> BuildPath("p", cl::desc("Build path"),
88                                         cl::Optional, cl::cat(Category),
89                                         cl::sub(*cl::AllSubCommands));
90 
91   static cl::list<std::string> SourcePaths(
92       cl::Positional, cl::desc("<source0> [... <sourceN>]"), OccurrencesFlag,
93       cl::cat(Category), cl::sub(*cl::AllSubCommands));
94 
95   static cl::list<std::string> ArgsAfter(
96       "extra-arg",
97       cl::desc("Additional argument to append to the compiler command line"),
98       cl::cat(Category), cl::sub(*cl::AllSubCommands));
99 
100   static cl::list<std::string> ArgsBefore(
101       "extra-arg-before",
102       cl::desc("Additional argument to prepend to the compiler command line"),
103       cl::cat(Category), cl::sub(*cl::AllSubCommands));
104 
105   cl::ResetAllOptionOccurrences();
106 
107   cl::HideUnrelatedOptions(Category);
108 
109   std::string ErrorMessage;
110   Compilations =
111       FixedCompilationDatabase::loadFromCommandLine(argc, argv, ErrorMessage);
112   if (!ErrorMessage.empty())
113     ErrorMessage.append("\n");
114   llvm::raw_string_ostream OS(ErrorMessage);
115   // Stop initializing if command-line option parsing failed.
116   if (!cl::ParseCommandLineOptions(argc, argv, Overview, &OS)) {
117     OS.flush();
118     return llvm::make_error<llvm::StringError>("[CommonOptionsParser]: " +
119                                                    ErrorMessage,
120                                                llvm::inconvertibleErrorCode());
121   }
122 
123   cl::PrintOptionValues();
124 
125   SourcePathList = SourcePaths;
126   if ((OccurrencesFlag == cl::ZeroOrMore || OccurrencesFlag == cl::Optional) &&
127       SourcePathList.empty())
128     return llvm::Error::success();
129   if (!Compilations) {
130     if (!BuildPath.empty()) {
131       Compilations =
132           CompilationDatabase::autoDetectFromDirectory(BuildPath, ErrorMessage);
133     } else {
134       Compilations = CompilationDatabase::autoDetectFromSource(SourcePaths[0],
135                                                                ErrorMessage);
136     }
137     if (!Compilations) {
138       llvm::errs() << "Error while trying to load a compilation database:\n"
139                    << ErrorMessage << "Running without flags.\n";
140       Compilations.reset(
141           new FixedCompilationDatabase(".", std::vector<std::string>()));
142     }
143   }
144   auto AdjustingCompilations =
145       std::make_unique<ArgumentsAdjustingCompilations>(
146           std::move(Compilations));
147   Adjuster =
148       getInsertArgumentAdjuster(ArgsBefore, ArgumentInsertPosition::BEGIN);
149   Adjuster = combineAdjusters(
150       std::move(Adjuster),
151       getInsertArgumentAdjuster(ArgsAfter, ArgumentInsertPosition::END));
152   AdjustingCompilations->appendArgumentsAdjuster(Adjuster);
153   Compilations = std::move(AdjustingCompilations);
154   return llvm::Error::success();
155 }
156 
create(int & argc,const char ** argv,llvm::cl::OptionCategory & Category,llvm::cl::NumOccurrencesFlag OccurrencesFlag,const char * Overview)157 llvm::Expected<CommonOptionsParser> CommonOptionsParser::create(
158     int &argc, const char **argv, llvm::cl::OptionCategory &Category,
159     llvm::cl::NumOccurrencesFlag OccurrencesFlag, const char *Overview) {
160   CommonOptionsParser Parser;
161   llvm::Error Err =
162       Parser.init(argc, argv, Category, OccurrencesFlag, Overview);
163   if (Err)
164     return std::move(Err);
165   return std::move(Parser);
166 }
167 
CommonOptionsParser(int & argc,const char ** argv,cl::OptionCategory & Category,llvm::cl::NumOccurrencesFlag OccurrencesFlag,const char * Overview)168 CommonOptionsParser::CommonOptionsParser(
169     int &argc, const char **argv, cl::OptionCategory &Category,
170     llvm::cl::NumOccurrencesFlag OccurrencesFlag, const char *Overview) {
171   llvm::Error Err = init(argc, argv, Category, OccurrencesFlag, Overview);
172   if (Err) {
173     llvm::report_fatal_error(
174         "CommonOptionsParser: failed to parse command-line arguments. " +
175         llvm::toString(std::move(Err)));
176   }
177 }
178