1 //===- Utils.h - Misc utilities for the front-end ---------------*- 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 header contains miscellaneous utilities for various front-end actions. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_CLANG_FRONTEND_UTILS_H 14 #define LLVM_CLANG_FRONTEND_UTILS_H 15 16 #include "clang/Basic/Diagnostic.h" 17 #include "clang/Basic/LLVM.h" 18 #include "clang/Driver/OptionUtils.h" 19 #include "clang/Frontend/DependencyOutputOptions.h" 20 #include "llvm/ADT/ArrayRef.h" 21 #include "llvm/ADT/IntrusiveRefCntPtr.h" 22 #include "llvm/ADT/StringMap.h" 23 #include "llvm/ADT/StringRef.h" 24 #include "llvm/ADT/StringSet.h" 25 #include "llvm/Support/FileCollector.h" 26 #include "llvm/Support/VirtualFileSystem.h" 27 #include <cstdint> 28 #include <memory> 29 #include <string> 30 #include <system_error> 31 #include <utility> 32 #include <vector> 33 34 namespace clang { 35 36 class ASTReader; 37 class CompilerInstance; 38 class CompilerInvocation; 39 class DiagnosticsEngine; 40 class ExternalSemaSource; 41 class FrontendOptions; 42 class PCHContainerReader; 43 class Preprocessor; 44 class PreprocessorOptions; 45 class PreprocessorOutputOptions; 46 class CodeGenOptions; 47 48 /// InitializePreprocessor - Initialize the preprocessor getting it and the 49 /// environment ready to process a single file. 50 void InitializePreprocessor(Preprocessor &PP, const PreprocessorOptions &PPOpts, 51 const PCHContainerReader &PCHContainerRdr, 52 const FrontendOptions &FEOpts, 53 const CodeGenOptions &CodeGenOpts); 54 55 /// DoPrintPreprocessedInput - Implement -E mode. 56 void DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS, 57 const PreprocessorOutputOptions &Opts); 58 59 /// An interface for collecting the dependencies of a compilation. Users should 60 /// use \c attachToPreprocessor and \c attachToASTReader to get all of the 61 /// dependencies. 62 /// FIXME: Migrate DependencyGraphGen to use this interface. 63 class DependencyCollector { 64 public: 65 virtual ~DependencyCollector(); 66 67 virtual void attachToPreprocessor(Preprocessor &PP); 68 virtual void attachToASTReader(ASTReader &R); getDependencies()69 ArrayRef<std::string> getDependencies() const { return Dependencies; } 70 71 /// Called when a new file is seen. Return true if \p Filename should be added 72 /// to the list of dependencies. 73 /// 74 /// The default implementation ignores <built-in> and system files. 75 virtual bool sawDependency(StringRef Filename, bool FromModule, 76 bool IsSystem, bool IsModuleFile, bool IsMissing); 77 78 /// Called when the end of the main file is reached. finishedMainFile(DiagnosticsEngine & Diags)79 virtual void finishedMainFile(DiagnosticsEngine &Diags) {} 80 81 /// Return true if system files should be passed to sawDependency(). needSystemDependencies()82 virtual bool needSystemDependencies() { return false; } 83 84 /// Add a dependency \p Filename if it has not been seen before and 85 /// sawDependency() returns true. 86 virtual void maybeAddDependency(StringRef Filename, bool FromModule, 87 bool IsSystem, bool IsModuleFile, 88 bool IsMissing); 89 90 protected: 91 /// Return true if the filename was added to the list of dependencies, false 92 /// otherwise. 93 bool addDependency(StringRef Filename); 94 95 private: 96 llvm::StringSet<> Seen; 97 std::vector<std::string> Dependencies; 98 }; 99 100 /// Builds a dependency file when attached to a Preprocessor (for includes) and 101 /// ASTReader (for module imports), and writes it out at the end of processing 102 /// a source file. Users should attach to the ast reader whenever a module is 103 /// loaded. 104 class DependencyFileGenerator : public DependencyCollector { 105 public: 106 DependencyFileGenerator(const DependencyOutputOptions &Opts); 107 108 void attachToPreprocessor(Preprocessor &PP) override; 109 110 void finishedMainFile(DiagnosticsEngine &Diags) override; 111 needSystemDependencies()112 bool needSystemDependencies() final { return IncludeSystemHeaders; } 113 114 bool sawDependency(StringRef Filename, bool FromModule, bool IsSystem, 115 bool IsModuleFile, bool IsMissing) final; 116 117 protected: 118 void outputDependencyFile(llvm::raw_ostream &OS); 119 120 private: 121 void outputDependencyFile(DiagnosticsEngine &Diags); 122 123 std::string OutputFile; 124 std::vector<std::string> Targets; 125 bool IncludeSystemHeaders; 126 bool PhonyTarget; 127 bool AddMissingHeaderDeps; 128 bool SeenMissingHeader; 129 bool IncludeModuleFiles; 130 DependencyOutputFormat OutputFormat; 131 unsigned InputFileIndex; 132 }; 133 134 /// Collects the dependencies for imported modules into a directory. Users 135 /// should attach to the AST reader whenever a module is loaded. 136 class ModuleDependencyCollector : public DependencyCollector { 137 std::string DestDir; 138 bool HasErrors = false; 139 llvm::StringSet<> Seen; 140 llvm::vfs::YAMLVFSWriter VFSWriter; 141 llvm::FileCollector::PathCanonicalizer Canonicalizer; 142 143 std::error_code copyToRoot(StringRef Src, StringRef Dst = {}); 144 145 public: ModuleDependencyCollector(std::string DestDir)146 ModuleDependencyCollector(std::string DestDir) 147 : DestDir(std::move(DestDir)) {} ~ModuleDependencyCollector()148 ~ModuleDependencyCollector() override { writeFileMap(); } 149 getDest()150 StringRef getDest() { return DestDir; } insertSeen(StringRef Filename)151 virtual bool insertSeen(StringRef Filename) { return Seen.insert(Filename).second; } 152 virtual void addFile(StringRef Filename, StringRef FileDst = {}); 153 addFileMapping(StringRef VPath,StringRef RPath)154 virtual void addFileMapping(StringRef VPath, StringRef RPath) { 155 VFSWriter.addFileMapping(VPath, RPath); 156 } 157 158 void attachToPreprocessor(Preprocessor &PP) override; 159 void attachToASTReader(ASTReader &R) override; 160 161 virtual void writeFileMap(); hasErrors()162 virtual bool hasErrors() { return HasErrors; } 163 }; 164 165 /// AttachDependencyGraphGen - Create a dependency graph generator, and attach 166 /// it to the given preprocessor. 167 void AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile, 168 StringRef SysRoot); 169 170 /// AttachHeaderIncludeGen - Create a header include list generator, and attach 171 /// it to the given preprocessor. 172 /// 173 /// \param DepOpts - Options controlling the output. 174 /// \param ShowAllHeaders - If true, show all header information instead of just 175 /// headers following the predefines buffer. This is useful for making sure 176 /// includes mentioned on the command line are also reported, but differs from 177 /// the default behavior used by -H. 178 /// \param OutputPath - If non-empty, a path to write the header include 179 /// information to, instead of writing to stderr. 180 /// \param ShowDepth - Whether to indent to show the nesting of the includes. 181 /// \param MSStyle - Whether to print in cl.exe /showIncludes style. 182 void AttachHeaderIncludeGen(Preprocessor &PP, 183 const DependencyOutputOptions &DepOpts, 184 bool ShowAllHeaders = false, 185 StringRef OutputPath = {}, 186 bool ShowDepth = true, bool MSStyle = false); 187 188 /// The ChainedIncludesSource class converts headers to chained PCHs in 189 /// memory, mainly for testing. 190 IntrusiveRefCntPtr<ExternalSemaSource> 191 createChainedIncludesSource(CompilerInstance &CI, 192 IntrusiveRefCntPtr<ExternalSemaSource> &Reader); 193 194 /// Optional inputs to createInvocation. 195 struct CreateInvocationOptions { 196 /// Receives diagnostics encountered while parsing command-line flags. 197 /// If not provided, these are printed to stderr. 198 IntrusiveRefCntPtr<DiagnosticsEngine> Diags = nullptr; 199 /// Used e.g. to probe for system headers locations. 200 /// If not provided, the real filesystem is used. 201 /// FIXME: the driver does perform some non-virtualized IO. 202 IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS = nullptr; 203 /// Whether to attempt to produce a non-null (possibly incorrect) invocation 204 /// if any errors were encountered. 205 /// By default, always return null on errors. 206 bool RecoverOnError = false; 207 /// Allow the driver to probe the filesystem for PCH files. 208 /// This is used to replace -include with -include-pch in the cc1 args. 209 /// FIXME: ProbePrecompiled=true is a poor, historical default. 210 /// It misbehaves if the PCH file is from GCC, has the wrong version, etc. 211 bool ProbePrecompiled = false; 212 /// If set, the target is populated with the cc1 args produced by the driver. 213 /// This may be populated even if createInvocation returns nullptr. 214 std::vector<std::string> *CC1Args = nullptr; 215 }; 216 217 /// Interpret clang arguments in preparation to parse a file. 218 /// 219 /// This simulates a number of steps Clang takes when its driver is invoked: 220 /// - choosing actions (e.g compile + link) to run 221 /// - probing the system for settings like standard library locations 222 /// - spawning a cc1 subprocess to compile code, with more explicit arguments 223 /// - in the cc1 process, assembling those arguments into a CompilerInvocation 224 /// which is used to configure the parser 225 /// 226 /// This simulation is lossy, e.g. in some situations one driver run would 227 /// result in multiple parses. (Multi-arch, CUDA, ...). 228 /// This function tries to select a reasonable invocation that tools should use. 229 /// 230 /// Args[0] should be the driver name, such as "clang" or "/usr/bin/g++". 231 /// Absolute path is preferred - this affects searching for system headers. 232 /// 233 /// May return nullptr if an invocation could not be determined. 234 /// See CreateInvocationOptions::ShouldRecoverOnErrors to try harder! 235 std::unique_ptr<CompilerInvocation> 236 createInvocation(ArrayRef<const char *> Args, 237 CreateInvocationOptions Opts = {}); 238 239 } // namespace clang 240 241 #endif // LLVM_CLANG_FRONTEND_UTILS_H 242