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