CommonOptionsParser.cpp revision 360784 
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
30using namespace clang::tooling;
31using namespace llvm;
32
33const 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
55void ArgumentsAdjustingCompilations::appendArgumentsAdjuster(
56    ArgumentsAdjuster Adjuster) {
57  Adjusters.push_back(std::move(Adjuster));
58}
59
60std::vector<CompileCommand> ArgumentsAdjustingCompilations::getCompileCommands(
61    StringRef FilePath) const {
62  return adjustCommands(Compilations->getCompileCommands(FilePath));
63}
64
65std::vector<std::string>
66ArgumentsAdjustingCompilations::getAllFiles() const {
67  return Compilations->getAllFiles();
68}
69
70std::vector<CompileCommand>
71ArgumentsAdjustingCompilations::getAllCompileCommands() const {
72  return adjustCommands(Compilations->getAllCompileCommands());
73}
74
75std::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
83llvm::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
157llvm::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
168CommonOptionsParser::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