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/Option/OptSpecifier.h"
26 #include "llvm/Support/FileCollector.h"
27 #include "llvm/Support/VirtualFileSystem.h"
28 #include <cstdint>
29 #include <memory>
30 #include <string>
31 #include <system_error>
32 #include <utility>
33 #include <vector>
34 
35 namespace clang {
36 
37 class ASTReader;
38 class CompilerInstance;
39 class CompilerInvocation;
40 class DiagnosticsEngine;
41 class ExternalSemaSource;
42 class FrontendOptions;
43 class PCHContainerReader;
44 class Preprocessor;
45 class PreprocessorOptions;
46 class PreprocessorOutputOptions;
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 
54 /// DoPrintPreprocessedInput - Implement -E mode.
55 void DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,
56                               const PreprocessorOutputOptions &Opts);
57 
58 /// An interface for collecting the dependencies of a compilation. Users should
59 /// use \c attachToPreprocessor and \c attachToASTReader to get all of the
60 /// dependencies.
61 /// FIXME: Migrate DependencyGraphGen to use this interface.
62 class DependencyCollector {
63 public:
64   virtual ~DependencyCollector();
65 
66   virtual void attachToPreprocessor(Preprocessor &PP);
67   virtual void attachToASTReader(ASTReader &R);
68   ArrayRef<std::string> getDependencies() const { return Dependencies; }
69 
70   /// Called when a new file is seen. Return true if \p Filename should be added
71   /// to the list of dependencies.
72   ///
73   /// The default implementation ignores <built-in> and system files.
74   virtual bool sawDependency(StringRef Filename, bool FromModule,
75                              bool IsSystem, bool IsModuleFile, bool IsMissing);
76 
77   /// Called when the end of the main file is reached.
78   virtual void finishedMainFile(DiagnosticsEngine &Diags) {}
79 
80   /// Return true if system files should be passed to sawDependency().
81   virtual bool needSystemDependencies() { return false; }
82 
83   /// Add a dependency \p Filename if it has not been seen before and
84   /// sawDependency() returns true.
85   virtual void maybeAddDependency(StringRef Filename, bool FromModule,
86                                   bool IsSystem, bool IsModuleFile,
87                                   bool IsMissing);
88 
89 protected:
90   /// Return true if the filename was added to the list of dependencies, false
91   /// otherwise.
92   bool addDependency(StringRef Filename);
93 
94 private:
95   llvm::StringSet<> Seen;
96   std::vector<std::string> Dependencies;
97 };
98 
99 /// Builds a dependency file when attached to a Preprocessor (for includes) and
100 /// ASTReader (for module imports), and writes it out at the end of processing
101 /// a source file.  Users should attach to the ast reader whenever a module is
102 /// loaded.
103 class DependencyFileGenerator : public DependencyCollector {
104 public:
105   DependencyFileGenerator(const DependencyOutputOptions &Opts);
106 
107   void attachToPreprocessor(Preprocessor &PP) override;
108 
109   void finishedMainFile(DiagnosticsEngine &Diags) override;
110 
111   bool needSystemDependencies() final override { return IncludeSystemHeaders; }
112 
113   bool sawDependency(StringRef Filename, bool FromModule, bool IsSystem,
114                      bool IsModuleFile, bool IsMissing) final override;
115 
116 protected:
117   void outputDependencyFile(llvm::raw_ostream &OS);
118 
119 private:
120   void outputDependencyFile(DiagnosticsEngine &Diags);
121 
122   std::string OutputFile;
123   std::vector<std::string> Targets;
124   bool IncludeSystemHeaders;
125   bool PhonyTarget;
126   bool AddMissingHeaderDeps;
127   bool SeenMissingHeader;
128   bool IncludeModuleFiles;
129   DependencyOutputFormat OutputFormat;
130   unsigned InputFileIndex;
131 };
132 
133 /// Collects the dependencies for imported modules into a directory.  Users
134 /// should attach to the AST reader whenever a module is loaded.
135 class ModuleDependencyCollector : public DependencyCollector {
136   std::string DestDir;
137   bool HasErrors = false;
138   llvm::StringSet<> Seen;
139   llvm::vfs::YAMLVFSWriter VFSWriter;
140   llvm::FileCollector::PathCanonicalizer Canonicalizer;
141 
142   std::error_code copyToRoot(StringRef Src, StringRef Dst = {});
143 
144 public:
145   ModuleDependencyCollector(std::string DestDir)
146       : DestDir(std::move(DestDir)) {}
147   ~ModuleDependencyCollector() override { writeFileMap(); }
148 
149   StringRef getDest() { return DestDir; }
150   virtual bool insertSeen(StringRef Filename) { return Seen.insert(Filename).second; }
151   virtual void addFile(StringRef Filename, StringRef FileDst = {});
152 
153   virtual void addFileMapping(StringRef VPath, StringRef RPath) {
154     VFSWriter.addFileMapping(VPath, RPath);
155   }
156 
157   void attachToPreprocessor(Preprocessor &PP) override;
158   void attachToASTReader(ASTReader &R) override;
159 
160   virtual void writeFileMap();
161   virtual bool hasErrors() { return HasErrors; }
162 };
163 
164 /// AttachDependencyGraphGen - Create a dependency graph generator, and attach
165 /// it to the given preprocessor.
166 void AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
167                               StringRef SysRoot);
168 
169 /// AttachHeaderIncludeGen - Create a header include list generator, and attach
170 /// it to the given preprocessor.
171 ///
172 /// \param DepOpts - Options controlling the output.
173 /// \param ShowAllHeaders - If true, show all header information instead of just
174 /// headers following the predefines buffer. This is useful for making sure
175 /// includes mentioned on the command line are also reported, but differs from
176 /// the default behavior used by -H.
177 /// \param OutputPath - If non-empty, a path to write the header include
178 /// information to, instead of writing to stderr.
179 /// \param ShowDepth - Whether to indent to show the nesting of the includes.
180 /// \param MSStyle - Whether to print in cl.exe /showIncludes style.
181 void AttachHeaderIncludeGen(Preprocessor &PP,
182                             const DependencyOutputOptions &DepOpts,
183                             bool ShowAllHeaders = false,
184                             StringRef OutputPath = {},
185                             bool ShowDepth = true, bool MSStyle = false);
186 
187 /// The ChainedIncludesSource class converts headers to chained PCHs in
188 /// memory, mainly for testing.
189 IntrusiveRefCntPtr<ExternalSemaSource>
190 createChainedIncludesSource(CompilerInstance &CI,
191                             IntrusiveRefCntPtr<ExternalSemaSource> &Reader);
192 
193 /// createInvocationFromCommandLine - Construct a compiler invocation object for
194 /// a command line argument vector.
195 ///
196 /// \param ShouldRecoverOnErrors - whether we should attempt to return a
197 /// non-null (and possibly incorrect) CompilerInvocation if any errors were
198 /// encountered. When this flag is false, always return null on errors.
199 ///
200 /// \param CC1Args - if non-null, will be populated with the args to cc1
201 /// expanded from \p Args. May be set even if nullptr is returned.
202 ///
203 /// \return A CompilerInvocation, or nullptr if none was built for the given
204 /// argument vector.
205 std::unique_ptr<CompilerInvocation> createInvocationFromCommandLine(
206     ArrayRef<const char *> Args,
207     IntrusiveRefCntPtr<DiagnosticsEngine> Diags =
208         IntrusiveRefCntPtr<DiagnosticsEngine>(),
209     IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS = nullptr,
210     bool ShouldRecoverOnErrors = false,
211     std::vector<std::string> *CC1Args = nullptr);
212 
213 // Frontend timing utils
214 
215 } // namespace clang
216 
217 #endif // LLVM_CLANG_FRONTEND_UTILS_H
218