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/VirtualFileSystem.h"
27 #include <cstdint>
28 #include <memory>
29 #include <string>
30 #include <system_error>
31 #include <utility>
32 #include <vector>
33 
34 namespace llvm {
35 
36 class Triple;
37 
38 } // namespace llvm
39 
40 namespace clang {
41 
42 class ASTReader;
43 class CompilerInstance;
44 class CompilerInvocation;
45 class DiagnosticsEngine;
46 class ExternalSemaSource;
47 class FrontendOptions;
48 class HeaderSearch;
49 class HeaderSearchOptions;
50 class LangOptions;
51 class PCHContainerReader;
52 class Preprocessor;
53 class PreprocessorOptions;
54 class PreprocessorOutputOptions;
55 
56 /// Apply the header search options to get given HeaderSearch object.
57 void ApplyHeaderSearchOptions(HeaderSearch &HS,
58                               const HeaderSearchOptions &HSOpts,
59                               const LangOptions &Lang,
60                               const llvm::Triple &triple);
61 
62 /// InitializePreprocessor - Initialize the preprocessor getting it and the
63 /// environment ready to process a single file.
64 void InitializePreprocessor(Preprocessor &PP, const PreprocessorOptions &PPOpts,
65                             const PCHContainerReader &PCHContainerRdr,
66                             const FrontendOptions &FEOpts);
67 
68 /// DoPrintPreprocessedInput - Implement -E mode.
69 void DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,
70                               const PreprocessorOutputOptions &Opts);
71 
72 /// An interface for collecting the dependencies of a compilation. Users should
73 /// use \c attachToPreprocessor and \c attachToASTReader to get all of the
74 /// dependencies.
75 /// FIXME: Migrate DependencyGraphGen to use this interface.
76 class DependencyCollector {
77 public:
78   virtual ~DependencyCollector();
79 
80   virtual void attachToPreprocessor(Preprocessor &PP);
81   virtual void attachToASTReader(ASTReader &R);
82   ArrayRef<std::string> getDependencies() const { return Dependencies; }
83 
84   /// Called when a new file is seen. Return true if \p Filename should be added
85   /// to the list of dependencies.
86   ///
87   /// The default implementation ignores <built-in> and system files.
88   virtual bool sawDependency(StringRef Filename, bool FromModule,
89                              bool IsSystem, bool IsModuleFile, bool IsMissing);
90 
91   /// Called when the end of the main file is reached.
92   virtual void finishedMainFile(DiagnosticsEngine &Diags) {}
93 
94   /// Return true if system files should be passed to sawDependency().
95   virtual bool needSystemDependencies() { return false; }
96 
97   /// Add a dependency \p Filename if it has not been seen before and
98   /// sawDependency() returns true.
99   virtual void maybeAddDependency(StringRef Filename, bool FromModule,
100                                   bool IsSystem, bool IsModuleFile,
101                                   bool IsMissing);
102 
103 protected:
104   /// Return true if the filename was added to the list of dependencies, false
105   /// otherwise.
106   bool addDependency(StringRef Filename);
107 
108 private:
109   llvm::StringSet<> Seen;
110   std::vector<std::string> Dependencies;
111 };
112 
113 /// Builds a dependency file when attached to a Preprocessor (for includes) and
114 /// ASTReader (for module imports), and writes it out at the end of processing
115 /// a source file.  Users should attach to the ast reader whenever a module is
116 /// loaded.
117 class DependencyFileGenerator : public DependencyCollector {
118 public:
119   DependencyFileGenerator(const DependencyOutputOptions &Opts);
120 
121   void attachToPreprocessor(Preprocessor &PP) override;
122 
123   void finishedMainFile(DiagnosticsEngine &Diags) override;
124 
125   bool needSystemDependencies() final override { return IncludeSystemHeaders; }
126 
127   bool sawDependency(StringRef Filename, bool FromModule, bool IsSystem,
128                      bool IsModuleFile, bool IsMissing) final override;
129 
130 protected:
131   void outputDependencyFile(llvm::raw_ostream &OS);
132 
133 private:
134   void outputDependencyFile(DiagnosticsEngine &Diags);
135 
136   std::string OutputFile;
137   std::vector<std::string> Targets;
138   bool IncludeSystemHeaders;
139   bool PhonyTarget;
140   bool AddMissingHeaderDeps;
141   bool SeenMissingHeader;
142   bool IncludeModuleFiles;
143   DependencyOutputFormat OutputFormat;
144   unsigned InputFileIndex;
145 };
146 
147 /// Collects the dependencies for imported modules into a directory.  Users
148 /// should attach to the AST reader whenever a module is loaded.
149 class ModuleDependencyCollector : public DependencyCollector {
150   std::string DestDir;
151   bool HasErrors = false;
152   llvm::StringSet<> Seen;
153   llvm::vfs::YAMLVFSWriter VFSWriter;
154   llvm::StringMap<std::string> SymLinkMap;
155 
156   bool getRealPath(StringRef SrcPath, SmallVectorImpl<char> &Result);
157   std::error_code copyToRoot(StringRef Src, StringRef Dst = {});
158 
159 public:
160   ModuleDependencyCollector(std::string DestDir)
161       : DestDir(std::move(DestDir)) {}
162   ~ModuleDependencyCollector() override { writeFileMap(); }
163 
164   StringRef getDest() { return DestDir; }
165   virtual bool insertSeen(StringRef Filename) { return Seen.insert(Filename).second; }
166   virtual void addFile(StringRef Filename, StringRef FileDst = {});
167 
168   virtual void addFileMapping(StringRef VPath, StringRef RPath) {
169     VFSWriter.addFileMapping(VPath, RPath);
170   }
171 
172   void attachToPreprocessor(Preprocessor &PP) override;
173   void attachToASTReader(ASTReader &R) override;
174 
175   virtual void writeFileMap();
176   virtual bool hasErrors() { return HasErrors; }
177 };
178 
179 /// AttachDependencyGraphGen - Create a dependency graph generator, and attach
180 /// it to the given preprocessor.
181 void AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
182                               StringRef SysRoot);
183 
184 /// AttachHeaderIncludeGen - Create a header include list generator, and attach
185 /// it to the given preprocessor.
186 ///
187 /// \param DepOpts - Options controlling the output.
188 /// \param ShowAllHeaders - If true, show all header information instead of just
189 /// headers following the predefines buffer. This is useful for making sure
190 /// includes mentioned on the command line are also reported, but differs from
191 /// the default behavior used by -H.
192 /// \param OutputPath - If non-empty, a path to write the header include
193 /// information to, instead of writing to stderr.
194 /// \param ShowDepth - Whether to indent to show the nesting of the includes.
195 /// \param MSStyle - Whether to print in cl.exe /showIncludes style.
196 void AttachHeaderIncludeGen(Preprocessor &PP,
197                             const DependencyOutputOptions &DepOpts,
198                             bool ShowAllHeaders = false,
199                             StringRef OutputPath = {},
200                             bool ShowDepth = true, bool MSStyle = false);
201 
202 /// The ChainedIncludesSource class converts headers to chained PCHs in
203 /// memory, mainly for testing.
204 IntrusiveRefCntPtr<ExternalSemaSource>
205 createChainedIncludesSource(CompilerInstance &CI,
206                             IntrusiveRefCntPtr<ExternalSemaSource> &Reader);
207 
208 /// createInvocationFromCommandLine - Construct a compiler invocation object for
209 /// a command line argument vector.
210 ///
211 /// \param ShouldRecoverOnErrors - whether we should attempt to return a
212 /// non-null (and possibly incorrect) CompilerInvocation if any errors were
213 /// encountered. When this flag is false, always return null on errors.
214 ///
215 /// \param CC1Args - if non-null, will be populated with the args to cc1
216 /// expanded from \p Args. May be set even if nullptr is returned.
217 ///
218 /// \return A CompilerInvocation, or nullptr if none was built for the given
219 /// argument vector.
220 std::unique_ptr<CompilerInvocation> createInvocationFromCommandLine(
221     ArrayRef<const char *> Args,
222     IntrusiveRefCntPtr<DiagnosticsEngine> Diags =
223         IntrusiveRefCntPtr<DiagnosticsEngine>(),
224     IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS = nullptr,
225     bool ShouldRecoverOnErrors = false,
226     std::vector<std::string> *CC1Args = nullptr);
227 
228 // Frontend timing utils
229 
230 /// If the user specifies the -ftime-report argument on an Clang command line
231 /// then the value of this boolean will be true, otherwise false.
232 extern bool FrontendTimesIsEnabled;
233 
234 } // namespace clang
235 
236 #endif // LLVM_CLANG_FRONTEND_UTILS_H
237