1 //===- Utils.h - Misc utilities for the front-end ---------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This header contains miscellaneous utilities for various front-end actions.
11 //===----------------------------------------------------------------------===//
13 #ifndef LLVM_CLANG_FRONTEND_UTILS_H
14 #define LLVM_CLANG_FRONTEND_UTILS_H
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"
30 #include <system_error>
37 class CompilerInstance;
38 class CompilerInvocation;
39 class DiagnosticsEngine;
40 class ExternalSemaSource;
41 class FrontendOptions;
42 class PCHContainerReader;
44 class PreprocessorOptions;
45 class PreprocessorOutputOptions;
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);
53 /// DoPrintPreprocessedInput - Implement -E mode.
54 void DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,
55 const PreprocessorOutputOptions &Opts);
57 /// An interface for collecting the dependencies of a compilation. Users should
58 /// use \c attachToPreprocessor and \c attachToASTReader to get all of the
60 /// FIXME: Migrate DependencyGraphGen to use this interface.
61 class DependencyCollector {
63 virtual ~DependencyCollector();
65 virtual void attachToPreprocessor(Preprocessor &PP);
66 virtual void attachToASTReader(ASTReader &R);
67 ArrayRef<std::string> getDependencies() const { return Dependencies; }
69 /// Called when a new file is seen. Return true if \p Filename should be added
70 /// to the list of dependencies.
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);
76 /// Called when the end of the main file is reached.
77 virtual void finishedMainFile(DiagnosticsEngine &Diags) {}
79 /// Return true if system files should be passed to sawDependency().
80 virtual bool needSystemDependencies() { return false; }
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,
89 /// Return true if the filename was added to the list of dependencies, false
91 bool addDependency(StringRef Filename);
94 llvm::StringSet<> Seen;
95 std::vector<std::string> Dependencies;
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
102 class DependencyFileGenerator : public DependencyCollector {
104 DependencyFileGenerator(const DependencyOutputOptions &Opts);
106 void attachToPreprocessor(Preprocessor &PP) override;
108 void finishedMainFile(DiagnosticsEngine &Diags) override;
110 bool needSystemDependencies() final { return IncludeSystemHeaders; }
112 bool sawDependency(StringRef Filename, bool FromModule, bool IsSystem,
113 bool IsModuleFile, bool IsMissing) final;
116 void outputDependencyFile(llvm::raw_ostream &OS);
119 void outputDependencyFile(DiagnosticsEngine &Diags);
121 std::string OutputFile;
122 std::vector<std::string> Targets;
123 bool IncludeSystemHeaders;
125 bool AddMissingHeaderDeps;
126 bool SeenMissingHeader;
127 bool IncludeModuleFiles;
128 DependencyOutputFormat OutputFormat;
129 unsigned InputFileIndex;
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 {
136 bool HasErrors = false;
137 llvm::StringSet<> Seen;
138 llvm::vfs::YAMLVFSWriter VFSWriter;
139 llvm::FileCollector::PathCanonicalizer Canonicalizer;
141 std::error_code copyToRoot(StringRef Src, StringRef Dst = {});
144 ModuleDependencyCollector(std::string DestDir)
145 : DestDir(std::move(DestDir)) {}
146 ~ModuleDependencyCollector() override { writeFileMap(); }
148 StringRef getDest() { return DestDir; }
149 virtual bool insertSeen(StringRef Filename) { return Seen.insert(Filename).second; }
150 virtual void addFile(StringRef Filename, StringRef FileDst = {});
152 virtual void addFileMapping(StringRef VPath, StringRef RPath) {
153 VFSWriter.addFileMapping(VPath, RPath);
156 void attachToPreprocessor(Preprocessor &PP) override;
157 void attachToASTReader(ASTReader &R) override;
159 virtual void writeFileMap();
160 virtual bool hasErrors() { return HasErrors; }
163 /// AttachDependencyGraphGen - Create a dependency graph generator, and attach
164 /// it to the given preprocessor.
165 void AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
168 /// AttachHeaderIncludeGen - Create a header include list generator, and attach
169 /// it to the given preprocessor.
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);
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);
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;
215 /// Interpret clang arguments in preparation to parse a file.
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
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.
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.
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 = {});
239 #endif // LLVM_CLANG_FRONTEND_UTILS_H