| //===--- DependencyFile.cpp - Generate dependency file --------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This code generates dependency files. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/Frontend/Utils.h" |
| #include "clang/Basic/FileManager.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/Frontend/DependencyOutputOptions.h" |
| #include "clang/Frontend/FrontendDiagnostic.h" |
| #include "clang/Lex/DirectoryLookup.h" |
| #include "clang/Lex/ModuleMap.h" |
| #include "clang/Lex/PPCallbacks.h" |
| #include "clang/Lex/Preprocessor.h" |
| #include "clang/Serialization/ASTReader.h" |
| #include "llvm/ADT/StringSet.h" |
| #include "llvm/ADT/StringSwitch.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/Path.h" |
| #include "llvm/Support/raw_ostream.h" |
| |
| using namespace clang; |
| |
| namespace { |
| struct DepCollectorPPCallbacks : public PPCallbacks { |
| DependencyCollector &DepCollector; |
| SourceManager &SM; |
| DiagnosticsEngine &Diags; |
| DepCollectorPPCallbacks(DependencyCollector &L, SourceManager &SM, |
| DiagnosticsEngine &Diags) |
| : DepCollector(L), SM(SM), Diags(Diags) {} |
| |
| void FileChanged(SourceLocation Loc, FileChangeReason Reason, |
| SrcMgr::CharacteristicKind FileType, |
| FileID PrevFID) override { |
| if (Reason != PPCallbacks::EnterFile) |
| return; |
| |
| // Dependency generation really does want to go all the way to the |
| // file entry for a source location to find out what is depended on. |
| // We do not want #line markers to affect dependency generation! |
| Optional<FileEntryRef> File = |
| SM.getFileEntryRefForID(SM.getFileID(SM.getExpansionLoc(Loc))); |
| if (!File) |
| return; |
| |
| StringRef Filename = |
| llvm::sys::path::remove_leading_dotslash(File->getName()); |
| |
| DepCollector.maybeAddDependency(Filename, /*FromModule*/false, |
| isSystem(FileType), |
| /*IsModuleFile*/false, /*IsMissing*/false); |
| } |
| |
| void FileSkipped(const FileEntryRef &SkippedFile, const Token &FilenameTok, |
| SrcMgr::CharacteristicKind FileType) override { |
| StringRef Filename = |
| llvm::sys::path::remove_leading_dotslash(SkippedFile.getName()); |
| DepCollector.maybeAddDependency(Filename, /*FromModule=*/false, |
| /*IsSystem=*/isSystem(FileType), |
| /*IsModuleFile=*/false, |
| /*IsMissing=*/false); |
| } |
| |
| void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok, |
| StringRef FileName, bool IsAngled, |
| CharSourceRange FilenameRange, const FileEntry *File, |
| StringRef SearchPath, StringRef RelativePath, |
| const Module *Imported, |
| SrcMgr::CharacteristicKind FileType) override { |
| if (!File) |
| DepCollector.maybeAddDependency(FileName, /*FromModule*/false, |
| /*IsSystem*/false, /*IsModuleFile*/false, |
| /*IsMissing*/true); |
| // Files that actually exist are handled by FileChanged. |
| } |
| |
| void HasInclude(SourceLocation Loc, StringRef SpelledFilename, bool IsAngled, |
| Optional<FileEntryRef> File, |
| SrcMgr::CharacteristicKind FileType) override { |
| if (!File) |
| return; |
| StringRef Filename = |
| llvm::sys::path::remove_leading_dotslash(File->getName()); |
| DepCollector.maybeAddDependency(Filename, /*FromModule=*/false, |
| /*IsSystem=*/isSystem(FileType), |
| /*IsModuleFile=*/false, |
| /*IsMissing=*/false); |
| } |
| |
| void EndOfMainFile() override { DepCollector.finishedMainFile(Diags); } |
| }; |
| |
| struct DepCollectorMMCallbacks : public ModuleMapCallbacks { |
| DependencyCollector &DepCollector; |
| DepCollectorMMCallbacks(DependencyCollector &DC) : DepCollector(DC) {} |
| |
| void moduleMapFileRead(SourceLocation Loc, const FileEntry &Entry, |
| bool IsSystem) override { |
| StringRef Filename = Entry.getName(); |
| DepCollector.maybeAddDependency(Filename, /*FromModule*/false, |
| /*IsSystem*/IsSystem, |
| /*IsModuleFile*/false, |
| /*IsMissing*/false); |
| } |
| }; |
| |
| struct DepCollectorASTListener : public ASTReaderListener { |
| DependencyCollector &DepCollector; |
| DepCollectorASTListener(DependencyCollector &L) : DepCollector(L) { } |
| bool needsInputFileVisitation() override { return true; } |
| bool needsSystemInputFileVisitation() override { |
| return DepCollector.needSystemDependencies(); |
| } |
| void visitModuleFile(StringRef Filename, |
| serialization::ModuleKind Kind) override { |
| DepCollector.maybeAddDependency(Filename, /*FromModule*/true, |
| /*IsSystem*/false, /*IsModuleFile*/true, |
| /*IsMissing*/false); |
| } |
| bool visitInputFile(StringRef Filename, bool IsSystem, |
| bool IsOverridden, bool IsExplicitModule) override { |
| if (IsOverridden || IsExplicitModule) |
| return true; |
| |
| DepCollector.maybeAddDependency(Filename, /*FromModule*/true, IsSystem, |
| /*IsModuleFile*/false, /*IsMissing*/false); |
| return true; |
| } |
| }; |
| } // end anonymous namespace |
| |
| void DependencyCollector::maybeAddDependency(StringRef Filename, bool FromModule, |
| bool IsSystem, bool IsModuleFile, |
| bool IsMissing) { |
| if (sawDependency(Filename, FromModule, IsSystem, IsModuleFile, IsMissing)) |
| addDependency(Filename); |
| } |
| |
| bool DependencyCollector::addDependency(StringRef Filename) { |
| if (Seen.insert(Filename).second) { |
| Dependencies.push_back(Filename); |
| return true; |
| } |
| return false; |
| } |
| |
| static bool isSpecialFilename(StringRef Filename) { |
| return llvm::StringSwitch<bool>(Filename) |
| .Case("<built-in>", true) |
| .Case("<stdin>", true) |
| .Default(false); |
| } |
| |
| bool DependencyCollector::sawDependency(StringRef Filename, bool FromModule, |
| bool IsSystem, bool IsModuleFile, |
| bool IsMissing) { |
| return !isSpecialFilename(Filename) && |
| (needSystemDependencies() || !IsSystem); |
| } |
| |
| DependencyCollector::~DependencyCollector() { } |
| void DependencyCollector::attachToPreprocessor(Preprocessor &PP) { |
| PP.addPPCallbacks(std::make_unique<DepCollectorPPCallbacks>( |
| *this, PP.getSourceManager(), PP.getDiagnostics())); |
| PP.getHeaderSearchInfo().getModuleMap().addModuleMapCallbacks( |
| std::make_unique<DepCollectorMMCallbacks>(*this)); |
| } |
| void DependencyCollector::attachToASTReader(ASTReader &R) { |
| R.addListener(std::make_unique<DepCollectorASTListener>(*this)); |
| } |
| |
| DependencyFileGenerator::DependencyFileGenerator( |
| const DependencyOutputOptions &Opts) |
| : OutputFile(Opts.OutputFile), Targets(Opts.Targets), |
| IncludeSystemHeaders(Opts.IncludeSystemHeaders), |
| PhonyTarget(Opts.UsePhonyTargets), |
| AddMissingHeaderDeps(Opts.AddMissingHeaderDeps), SeenMissingHeader(false), |
| IncludeModuleFiles(Opts.IncludeModuleFiles), |
| OutputFormat(Opts.OutputFormat), InputFileIndex(0) { |
| for (const auto &ExtraDep : Opts.ExtraDeps) { |
| if (addDependency(ExtraDep)) |
| ++InputFileIndex; |
| } |
| } |
| |
| void DependencyFileGenerator::attachToPreprocessor(Preprocessor &PP) { |
| // Disable the "file not found" diagnostic if the -MG option was given. |
| if (AddMissingHeaderDeps) |
| PP.SetSuppressIncludeNotFoundError(true); |
| |
| DependencyCollector::attachToPreprocessor(PP); |
| } |
| |
| bool DependencyFileGenerator::sawDependency(StringRef Filename, bool FromModule, |
| bool IsSystem, bool IsModuleFile, |
| bool IsMissing) { |
| if (IsMissing) { |
| // Handle the case of missing file from an inclusion directive. |
| if (AddMissingHeaderDeps) |
| return true; |
| SeenMissingHeader = true; |
| return false; |
| } |
| if (IsModuleFile && !IncludeModuleFiles) |
| return false; |
| |
| if (isSpecialFilename(Filename)) |
| return false; |
| |
| if (IncludeSystemHeaders) |
| return true; |
| |
| return !IsSystem; |
| } |
| |
| void DependencyFileGenerator::finishedMainFile(DiagnosticsEngine &Diags) { |
| outputDependencyFile(Diags); |
| } |
| |
| /// Print the filename, with escaping or quoting that accommodates the three |
| /// most likely tools that use dependency files: GNU Make, BSD Make, and |
| /// NMake/Jom. |
| /// |
| /// BSD Make is the simplest case: It does no escaping at all. This means |
| /// characters that are normally delimiters, i.e. space and # (the comment |
| /// character) simply aren't supported in filenames. |
| /// |
| /// GNU Make does allow space and # in filenames, but to avoid being treated |
| /// as a delimiter or comment, these must be escaped with a backslash. Because |
| /// backslash is itself the escape character, if a backslash appears in a |
| /// filename, it should be escaped as well. (As a special case, $ is escaped |
| /// as $$, which is the normal Make way to handle the $ character.) |
| /// For compatibility with BSD Make and historical practice, if GNU Make |
| /// un-escapes characters in a filename but doesn't find a match, it will |
| /// retry with the unmodified original string. |
| /// |
| /// GCC tries to accommodate both Make formats by escaping any space or # |
| /// characters in the original filename, but not escaping backslashes. The |
| /// apparent intent is so that filenames with backslashes will be handled |
| /// correctly by BSD Make, and by GNU Make in its fallback mode of using the |
| /// unmodified original string; filenames with # or space characters aren't |
| /// supported by BSD Make at all, but will be handled correctly by GNU Make |
| /// due to the escaping. |
| /// |
| /// A corner case that GCC gets only partly right is when the original filename |
| /// has a backslash immediately followed by space or #. GNU Make would expect |
| /// this backslash to be escaped; however GCC escapes the original backslash |
| /// only when followed by space, not #. It will therefore take a dependency |
| /// from a directive such as |
| /// #include "a\ b\#c.h" |
| /// and emit it as |
| /// a\\\ b\\#c.h |
| /// which GNU Make will interpret as |
| /// a\ b\ |
| /// followed by a comment. Failing to find this file, it will fall back to the |
| /// original string, which probably doesn't exist either; in any case it won't |
| /// find |
| /// a\ b\#c.h |
| /// which is the actual filename specified by the include directive. |
| /// |
| /// Clang does what GCC does, rather than what GNU Make expects. |
| /// |
| /// NMake/Jom has a different set of scary characters, but wraps filespecs in |
| /// double-quotes to avoid misinterpreting them; see |
| /// https://msdn.microsoft.com/en-us/library/dd9y37ha.aspx for NMake info, |
| /// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx |
| /// for Windows file-naming info. |
| static void PrintFilename(raw_ostream &OS, StringRef Filename, |
| DependencyOutputFormat OutputFormat) { |
| // Convert filename to platform native path |
| llvm::SmallString<256> NativePath; |
| llvm::sys::path::native(Filename.str(), NativePath); |
| |
| if (OutputFormat == DependencyOutputFormat::NMake) { |
| // Add quotes if needed. These are the characters listed as "special" to |
| // NMake, that are legal in a Windows filespec, and that could cause |
| // misinterpretation of the dependency string. |
| if (NativePath.find_first_of(" #${}^!") != StringRef::npos) |
| OS << '\"' << NativePath << '\"'; |
| else |
| OS << NativePath; |
| return; |
| } |
| assert(OutputFormat == DependencyOutputFormat::Make); |
| for (unsigned i = 0, e = NativePath.size(); i != e; ++i) { |
| if (NativePath[i] == '#') // Handle '#' the broken gcc way. |
| OS << '\\'; |
| else if (NativePath[i] == ' ') { // Handle space correctly. |
| OS << '\\'; |
| unsigned j = i; |
| while (j > 0 && NativePath[--j] == '\\') |
| OS << '\\'; |
| } else if (NativePath[i] == '$') // $ is escaped by $$. |
| OS << '$'; |
| OS << NativePath[i]; |
| } |
| } |
| |
| void DependencyFileGenerator::outputDependencyFile(DiagnosticsEngine &Diags) { |
| if (SeenMissingHeader) { |
| llvm::sys::fs::remove(OutputFile); |
| return; |
| } |
| |
| std::error_code EC; |
| llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::OF_Text); |
| if (EC) { |
| Diags.Report(diag::err_fe_error_opening) << OutputFile << EC.message(); |
| return; |
| } |
| |
| outputDependencyFile(OS); |
| } |
| |
| void DependencyFileGenerator::outputDependencyFile(llvm::raw_ostream &OS) { |
| // Write out the dependency targets, trying to avoid overly long |
| // lines when possible. We try our best to emit exactly the same |
| // dependency file as GCC (4.2), assuming the included files are the |
| // same. |
| const unsigned MaxColumns = 75; |
| unsigned Columns = 0; |
| |
| for (StringRef Target : Targets) { |
| unsigned N = Target.size(); |
| if (Columns == 0) { |
| Columns += N; |
| } else if (Columns + N + 2 > MaxColumns) { |
| Columns = N + 2; |
| OS << " \\\n "; |
| } else { |
| Columns += N + 1; |
| OS << ' '; |
| } |
| // Targets already quoted as needed. |
| OS << Target; |
| } |
| |
| OS << ':'; |
| Columns += 1; |
| |
| // Now add each dependency in the order it was seen, but avoiding |
| // duplicates. |
| ArrayRef<std::string> Files = getDependencies(); |
| for (StringRef File : Files) { |
| // Start a new line if this would exceed the column limit. Make |
| // sure to leave space for a trailing " \" in case we need to |
| // break the line on the next iteration. |
| unsigned N = File.size(); |
| if (Columns + (N + 1) + 2 > MaxColumns) { |
| OS << " \\\n "; |
| Columns = 2; |
| } |
| OS << ' '; |
| PrintFilename(OS, File, OutputFormat); |
| Columns += N + 1; |
| } |
| OS << '\n'; |
| |
| // Create phony targets if requested. |
| if (PhonyTarget && !Files.empty()) { |
| unsigned Index = 0; |
| for (auto I = Files.begin(), E = Files.end(); I != E; ++I) { |
| if (Index++ == InputFileIndex) |
| continue; |
| OS << '\n'; |
| PrintFilename(OS, *I, OutputFormat); |
| OS << ":\n"; |
| } |
| } |
| } |
