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
34namespace clang {
35
36class ASTReader;
37class CompilerInstance;
38class CompilerInvocation;
39class DiagnosticsEngine;
40class ExternalSemaSource;
41class FrontendOptions;
42class PCHContainerReader;
43class Preprocessor;
44class PreprocessorOptions;
45class PreprocessorOutputOptions;
46class CodeGenOptions;
47
48/// InitializePreprocessor - Initialize the preprocessor getting it and the
49/// environment ready to process a single file.
50void InitializePreprocessor(Preprocessor &PP, const PreprocessorOptions &PPOpts,
51 const PCHContainerReader &PCHContainerRdr,
52 const FrontendOptions &FEOpts,
53 const CodeGenOptions &CodeGenOpts);
54
55/// DoPrintPreprocessedInput - Implement -E mode.
56void 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.
63class DependencyCollector {
64public:
65 virtual ~DependencyCollector();
66
67 virtual void attachToPreprocessor(Preprocessor &PP);
68 virtual void attachToASTReader(ASTReader &R);
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.
79 virtual void finishedMainFile(DiagnosticsEngine &Diags) {}
80
81 /// Return true if system files should be passed to sawDependency().
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
90protected:
91 /// Return true if the filename was added to the list of dependencies, false
92 /// otherwise.
93 bool addDependency(StringRef Filename);
94
95private:
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.
104class DependencyFileGenerator : public DependencyCollector {
105public:
106 DependencyFileGenerator(const DependencyOutputOptions &Opts);
107
108 void attachToPreprocessor(Preprocessor &PP) override;
109
110 void finishedMainFile(DiagnosticsEngine &Diags) override;
111
112 bool needSystemDependencies() final { return IncludeSystemHeaders; }
113
114 bool sawDependency(StringRef Filename, bool FromModule, bool IsSystem,
115 bool IsModuleFile, bool IsMissing) final;
116
117protected:
118 void outputDependencyFile(llvm::raw_ostream &OS);
119
120private:
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.
136class 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
145public:
146 ModuleDependencyCollector(std::string DestDir)
147 : DestDir(std::move(DestDir)) {}
148 ~ModuleDependencyCollector() override { writeFileMap(); }
149
150 StringRef getDest() { return DestDir; }
151 virtual bool insertSeen(StringRef Filename) { return Seen.insert(key: Filename).second; }
152 virtual void addFile(StringRef Filename, StringRef FileDst = {});
153
154 virtual void addFileMapping(StringRef VPath, StringRef RPath) {
155 VFSWriter.addFileMapping(VirtualPath: VPath, RealPath: RPath);
156 }
157
158 void attachToPreprocessor(Preprocessor &PP) override;
159 void attachToASTReader(ASTReader &R) override;
160
161 virtual void writeFileMap();
162 virtual bool hasErrors() { return HasErrors; }
163};
164
165/// AttachDependencyGraphGen - Create a dependency graph generator, and attach
166/// it to the given preprocessor.
167void 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.
182void 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.
190IntrusiveRefCntPtr<ExternalSemaSource>
191createChainedIncludesSource(CompilerInstance &CI,
192 IntrusiveRefCntPtr<ExternalSemaSource> &Reader);
193
194/// Optional inputs to createInvocation.
195struct 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!
235std::unique_ptr<CompilerInvocation>
236createInvocation(ArrayRef<const char *> Args,
237 CreateInvocationOptions Opts = {});
238
239} // namespace clang
240
241#endif // LLVM_CLANG_FRONTEND_UTILS_H
242