clang-tools-extra/clang-doc/tool/ClangDocMain.cpp

   1 //===-- ClangDocMain.cpp - ClangDoc -----------------------------*- C++ -*-===//
   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 tool for generating C and C++ documentation from source code
  10 // and comments. Generally, it runs a LibTooling FrontendAction on source files,
  11 // mapping each declaration in those files to its USR and serializing relevant
  12 // information into LLVM bitcode. It then runs a pass over the collected
  13 // declaration information, reducing by USR. There is an option to dump this
  14 // intermediate result to bitcode. Finally, it hands the reduced information
  15 // off to a generator, which does the final parsing from the intermediate
  16 // representation to the desired output format.
  17 //
  18 //===----------------------------------------------------------------------===//
  19
  20 #include "BitcodeReader.h"
  21 #include "BitcodeWriter.h"
  22 #include "ClangDoc.h"
  23 #include "Generators.h"
  24 #include "Representation.h"
  25 #include "clang/AST/AST.h"
  26 #include "clang/AST/Decl.h"
  27 #include "clang/ASTMatchers/ASTMatchFinder.h"
  28 #include "clang/ASTMatchers/ASTMatchersInternal.h"
  29 #include "clang/Driver/Options.h"
  30 #include "clang/Frontend/FrontendActions.h"
  31 #include "clang/Tooling/AllTUsExecution.h"
  32 #include "clang/Tooling/CommonOptionsParser.h"
  33 #include "clang/Tooling/Execution.h"
  34 #include "clang/Tooling/Tooling.h"
  35 #include "llvm/ADT/APFloat.h"
  36 #include "llvm/Support/CommandLine.h"
  37 #include "llvm/Support/Error.h"
  38 #include "llvm/Support/FileSystem.h"
  39 #include "llvm/Support/Mutex.h"
  40 #include "llvm/Support/Path.h"
  41 #include "llvm/Support/Process.h"
  42 #include "llvm/Support/Signals.h"
  43 #include "llvm/Support/ThreadPool.h"
  44 #include "llvm/Support/raw_ostream.h"
  45 #include <atomic>
  46 #include <mutex>
  47 #include <string>
  48
  49 using namespace clang::ast_matchers;
  50 using namespace clang::tooling;
  51 using namespace clang;
  52
  53 static llvm::cl::extrahelp CommonHelp(CommonOptionsParser::HelpMessage);
  54 static llvm::cl::OptionCategory ClangDocCategory("clang-doc options");
  55
  56 static llvm::cl::opt<std::string>
  57     ProjectName("project-name", llvm::cl::desc("Name of project."),
  58                 llvm::cl::cat(ClangDocCategory));
  59
  60 static llvm::cl::opt<bool> IgnoreMappingFailures(
  61     "ignore-map-errors",
  62     llvm::cl::desc("Continue if files are not mapped correctly."),
  63     llvm::cl::init(true), llvm::cl::cat(ClangDocCategory));
  64
  65 static llvm::cl::opt<std::string>
  66     OutDirectory("output",
  67                  llvm::cl::desc("Directory for outputting generated files."),
  68                  llvm::cl::init("docs"), llvm::cl::cat(ClangDocCategory));
  69
  70 static llvm::cl::opt<bool>
  71     PublicOnly("public", llvm::cl::desc("Document only public declarations."),
  72                llvm::cl::init(false), llvm::cl::cat(ClangDocCategory));
  73
  74 static llvm::cl::opt<bool> DoxygenOnly(
  75     "doxygen",
  76     llvm::cl::desc("Use only doxygen-style comments to generate docs."),
  77     llvm::cl::init(false), llvm::cl::cat(ClangDocCategory));
  78
  79 static llvm::cl::list<std::string> UserStylesheets(
  80     "stylesheets", llvm::cl::CommaSeparated,
  81     llvm::cl::desc("CSS stylesheets to extend the default styles."),
  82     llvm::cl::cat(ClangDocCategory));
  83
  84 static llvm::cl::opt<std::string> SourceRoot("source-root", llvm::cl::desc(R"(
  85 Directory where processed files are stored.
  86 Links to definition locations will only be
  87 generated if the file is in this dir.)"),
  88                                              llvm::cl::cat(ClangDocCategory));
  89
  90 static llvm::cl::opt<std::string>
  91     RepositoryUrl("repository", llvm::cl::desc(R"(
  92 URL of repository that hosts code.
  93 Used for links to definition locations.)"),
  94                   llvm::cl::cat(ClangDocCategory));
  95
  96 enum OutputFormatTy {
  97   md,
  98   yaml,
  99   html,
 100 };
 101
 102 static llvm::cl::opt<OutputFormatTy>
 103     FormatEnum("format", llvm::cl::desc("Format for outputted docs."),
 104                llvm::cl::values(clEnumValN(OutputFormatTy::yaml, "yaml",
 105                                            "Documentation in YAML format."),
 106                                 clEnumValN(OutputFormatTy::md, "md",
 107                                            "Documentation in MD format."),
 108                                 clEnumValN(OutputFormatTy::html, "html",
 109                                            "Documentation in HTML format.")),
 110                llvm::cl::init(OutputFormatTy::yaml),
 111                llvm::cl::cat(ClangDocCategory));
 112
 113 std::string getFormatString() {
 114   switch (FormatEnum) {
 115   case OutputFormatTy::yaml:
 116     return "yaml";
 117   case OutputFormatTy::md:
 118     return "md";
 119   case OutputFormatTy::html:
 120     return "html";
 121   }
 122   llvm_unreachable("Unknown OutputFormatTy");
 123 }
 124
 125 // This function isn't referenced outside its translation unit, but it
 126 // can't use the "static" keyword because its address is used for
 127 // GetMainExecutable (since some platforms don't support taking the
 128 // address of main, and some platforms can't implement GetMainExecutable
 129 // without being given the address of a function in the main executable).
 130 std::string GetExecutablePath(const char *Argv0, void *MainAddr) {
 131   return llvm::sys::fs::getMainExecutable(Argv0, MainAddr);
 132 }
 133
 134 int main(int argc, const char **argv) {
 135   llvm::sys::PrintStackTraceOnErrorSignal(argv[0]);
 136   std::error_code OK;
 137
 138   const char *Overview =
 139     R"(Generates documentation from source code and comments.
 140
 141 Example usage for files without flags (default):
 142
 143   $ clang-doc File1.cpp File2.cpp ... FileN.cpp
 144
 145 Example usage for a project using a compile commands database:
 146
 147   $ clang-doc --executor=all-TUs compile_commands.json
 148 )";
 149
 150   auto Executor = clang::tooling::createExecutorFromCommandLineArgs(
 151       argc, argv, ClangDocCategory, Overview);
 152
 153   if (!Executor) {
 154     llvm::errs() << toString(Executor.takeError()) << "\n";
 155     return 1;
 156   }
 157
 158   // Fail early if an invalid format was provided.
 159   std::string Format = getFormatString();
 160   llvm::outs() << "Emiting docs in " << Format << " format.\n";
 161   auto G = doc::findGeneratorByName(Format);
 162   if (!G) {
 163     llvm::errs() << toString(G.takeError()) << "\n";
 164     return 1;
 165   }
 166
 167   ArgumentsAdjuster ArgAdjuster;
 168   if (!DoxygenOnly)
 169     ArgAdjuster = combineAdjusters(
 170         getInsertArgumentAdjuster("-fparse-all-comments",
 171                                   tooling::ArgumentInsertPosition::END),
 172         ArgAdjuster);
 173
 174   clang::doc::ClangDocContext CDCtx = {
 175       Executor->get()->getExecutionContext(),
 176       ProjectName,
 177       PublicOnly,
 178       OutDirectory,
 179       SourceRoot,
 180       RepositoryUrl,
 181       {UserStylesheets.begin(), UserStylesheets.end()},
 182       {"index.js", "index_json.js"}};
 183
 184   if (Format == "html") {
 185     void *MainAddr = (void *)(intptr_t)GetExecutablePath;
 186     std::string ClangDocPath = GetExecutablePath(argv[0], MainAddr);
 187     llvm::SmallString<128> NativeClangDocPath;
 188     llvm::sys::path::native(ClangDocPath, NativeClangDocPath);
 189     llvm::SmallString<128> AssetsPath;
 190     AssetsPath = llvm::sys::path::parent_path(NativeClangDocPath);
 191     llvm::sys::path::append(AssetsPath, "..", "share", "clang");
 192     llvm::SmallString<128> DefaultStylesheet;
 193     llvm::sys::path::native(AssetsPath, DefaultStylesheet);
 194     llvm::sys::path::append(DefaultStylesheet,
 195                             "clang-doc-default-stylesheet.css");
 196     llvm::SmallString<128> IndexJS;
 197     llvm::sys::path::native(AssetsPath, IndexJS);
 198     llvm::sys::path::append(IndexJS, "index.js");
 199     CDCtx.UserStylesheets.insert(CDCtx.UserStylesheets.begin(),
 200                                  std::string(DefaultStylesheet.str()));
 201     CDCtx.FilesToCopy.emplace_back(IndexJS.str());
 202   }
 203
 204   // Mapping phase
 205   llvm::outs() << "Mapping decls...\n";
 206   auto Err =
 207       Executor->get()->execute(doc::newMapperActionFactory(CDCtx), ArgAdjuster);
 208   if (Err) {
 209     if (IgnoreMappingFailures)
 210       llvm::errs() << "Error mapping decls in files. Clang-doc will ignore "
 211                       "these files and continue:\n"
 212                    << toString(std::move(Err)) << "\n";
 213     else {
 214       llvm::errs() << toString(std::move(Err)) << "\n";
 215       return 1;
 216     }
 217   }
 218
 219   // Collect values into output by key.
 220   // In ToolResults, the Key is the hashed USR and the value is the
 221   // bitcode-encoded representation of the Info object.
 222   llvm::outs() << "Collecting infos...\n";
 223   llvm::StringMap<std::vector<StringRef>> USRToBitcode;
 224   Executor->get()->getToolResults()->forEachResult(
 225       [&](StringRef Key, StringRef Value) {
 226         auto R = USRToBitcode.try_emplace(Key, std::vector<StringRef>());
 227         R.first->second.emplace_back(Value);
 228       });
 229
 230   // Collects all Infos according to their unique USR value. This map is added
 231   // to from the thread pool below and is protected by the USRToInfoMutex.
 232   llvm::sys::Mutex USRToInfoMutex;
 233   llvm::StringMap<std::unique_ptr<doc::Info>> USRToInfo;
 234
 235   // First reducing phase (reduce all decls into one info per decl).
 236   llvm::outs() << "Reducing " << USRToBitcode.size() << " infos...\n";
 237   std::atomic<bool> Error;
 238   Error = false;
 239   llvm::sys::Mutex IndexMutex;
 240   // ExecutorConcurrency is a flag exposed by AllTUsExecution.h
 241   llvm::ThreadPool Pool(llvm::hardware_concurrency(ExecutorConcurrency));
 242   for (auto &Group : USRToBitcode) {
 243     Pool.async([&]() {
 244       std::vector<std::unique_ptr<doc::Info>> Infos;
 245
 246       for (auto &Bitcode : Group.getValue()) {
 247         llvm::BitstreamCursor Stream(Bitcode);
 248         doc::ClangDocBitcodeReader Reader(Stream);
 249         auto ReadInfos = Reader.readBitcode();
 250         if (!ReadInfos) {
 251           llvm::errs() << toString(ReadInfos.takeError()) << "\n";
 252           Error = true;
 253           return;
 254         }
 255         std::move(ReadInfos->begin(), ReadInfos->end(),
 256                   std::back_inserter(Infos));
 257       }
 258
 259       auto Reduced = doc::mergeInfos(Infos);
 260       if (!Reduced) {
 261         llvm::errs() << llvm::toString(Reduced.takeError());
 262         return;
 263       }
 264
 265       // Add a reference to this Info in the Index
 266       {
 267         std::lock_guard<llvm::sys::Mutex> Guard(IndexMutex);
 268         clang::doc::Generator::addInfoToIndex(CDCtx.Idx, Reduced.get().get());
 269       }
 270
 271       // Save in the result map (needs a lock due to threaded access).
 272       {
 273         std::lock_guard<llvm::sys::Mutex> Guard(USRToInfoMutex);
 274         USRToInfo[Group.getKey()] = std::move(Reduced.get());
 275       }
 276     });
 277   }
 278
 279   Pool.wait();
 280
 281   if (Error)
 282     return 1;
 283
 284   // Ensure the root output directory exists.
 285   if (std::error_code Err = llvm::sys::fs::create_directories(OutDirectory);
 286       Err != std::error_code()) {
 287     llvm::errs() << "Failed to create directory '" << OutDirectory << "'\n";
 288     return 1;
 289   }
 290
 291   // Run the generator.
 292   llvm::outs() << "Generating docs...\n";
 293   if (auto Err =
 294           G->get()->generateDocs(OutDirectory, std::move(USRToInfo), CDCtx)) {
 295     llvm::errs() << toString(std::move(Err)) << "\n";
 296     return 1;
 297   }
 298
 299   llvm::outs() << "Generating assets for docs...\n";
 300   Err = G->get()->createResources(CDCtx);
 301   if (Err) {
 302     llvm::errs() << toString(std::move(Err)) << "\n";
 303     return 1;
 304   }
 305
 306   return 0;
 307 }