1 //===--- FrontendActions.cpp ----------------------------------------------===//
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 #include "clang/Rewrite/Frontend/FrontendActions.h"
10 #include "clang/AST/ASTConsumer.h"
11 #include "clang/Basic/CharInfo.h"
12 #include "clang/Basic/LangStandard.h"
13 #include "clang/Config/config.h"
14 #include "clang/Frontend/CompilerInstance.h"
15 #include "clang/Frontend/FrontendActions.h"
16 #include "clang/Frontend/FrontendDiagnostic.h"
17 #include "clang/Frontend/Utils.h"
18 #include "clang/Lex/Preprocessor.h"
19 #include "clang/Lex/PreprocessorOptions.h"
20 #include "clang/Rewrite/Frontend/ASTConsumers.h"
21 #include "clang/Rewrite/Frontend/FixItRewriter.h"
22 #include "clang/Rewrite/Frontend/Rewriters.h"
23 #include "clang/Serialization/ASTReader.h"
24 #include "clang/Serialization/ModuleFile.h"
25 #include "clang/Serialization/ModuleManager.h"
26 #include "llvm/ADT/DenseSet.h"
27 #include "llvm/Support/CrashRecoveryContext.h"
28 #include "llvm/Support/FileSystem.h"
29 #include "llvm/Support/Path.h"
30 #include "llvm/Support/raw_ostream.h"
31 #include <memory>
32 #include <utility>
33 
34 using namespace clang;
35 
36 //===----------------------------------------------------------------------===//
37 // AST Consumer Actions
38 //===----------------------------------------------------------------------===//
39 
40 std::unique_ptr<ASTConsumer>
41 HTMLPrintAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
42   if (std::unique_ptr<raw_ostream> OS =
43           CI.createDefaultOutputFile(false, InFile))
44     return CreateHTMLPrinter(std::move(OS), CI.getPreprocessor());
45   return nullptr;
46 }
47 
48 FixItAction::FixItAction() {}
49 FixItAction::~FixItAction() {}
50 
51 std::unique_ptr<ASTConsumer>
52 FixItAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
53   return std::make_unique<ASTConsumer>();
54 }
55 
56 namespace {
57 class FixItRewriteInPlace : public FixItOptions {
58 public:
59   FixItRewriteInPlace() { InPlace = true; }
60 
61   std::string RewriteFilename(const std::string &Filename, int &fd) override {
62     llvm_unreachable("don't call RewriteFilename for inplace rewrites");
63   }
64 };
65 
66 class FixItActionSuffixInserter : public FixItOptions {
67   std::string NewSuffix;
68 
69 public:
70   FixItActionSuffixInserter(std::string NewSuffix, bool FixWhatYouCan)
71       : NewSuffix(std::move(NewSuffix)) {
72     this->FixWhatYouCan = FixWhatYouCan;
73   }
74 
75   std::string RewriteFilename(const std::string &Filename, int &fd) override {
76     fd = -1;
77     SmallString<128> Path(Filename);
78     llvm::sys::path::replace_extension(Path,
79       NewSuffix + llvm::sys::path::extension(Path));
80     return std::string(Path);
81   }
82 };
83 
84 class FixItRewriteToTemp : public FixItOptions {
85 public:
86   std::string RewriteFilename(const std::string &Filename, int &fd) override {
87     SmallString<128> Path;
88     llvm::sys::fs::createTemporaryFile(llvm::sys::path::filename(Filename),
89                                        llvm::sys::path::extension(Filename).drop_front(), fd,
90                                        Path);
91     return std::string(Path);
92   }
93 };
94 } // end anonymous namespace
95 
96 bool FixItAction::BeginSourceFileAction(CompilerInstance &CI) {
97   const FrontendOptions &FEOpts = getCompilerInstance().getFrontendOpts();
98   if (!FEOpts.FixItSuffix.empty()) {
99     FixItOpts.reset(new FixItActionSuffixInserter(FEOpts.FixItSuffix,
100                                                   FEOpts.FixWhatYouCan));
101   } else {
102     FixItOpts.reset(new FixItRewriteInPlace);
103     FixItOpts->FixWhatYouCan = FEOpts.FixWhatYouCan;
104   }
105   Rewriter.reset(new FixItRewriter(CI.getDiagnostics(), CI.getSourceManager(),
106                                    CI.getLangOpts(), FixItOpts.get()));
107   return true;
108 }
109 
110 void FixItAction::EndSourceFileAction() {
111   // Otherwise rewrite all files.
112   Rewriter->WriteFixedFiles();
113 }
114 
115 bool FixItRecompile::BeginInvocation(CompilerInstance &CI) {
116 
117   std::vector<std::pair<std::string, std::string> > RewrittenFiles;
118   bool err = false;
119   {
120     const FrontendOptions &FEOpts = CI.getFrontendOpts();
121     std::unique_ptr<FrontendAction> FixAction(new SyntaxOnlyAction());
122     if (FixAction->BeginSourceFile(CI, FEOpts.Inputs[0])) {
123       std::unique_ptr<FixItOptions> FixItOpts;
124       if (FEOpts.FixToTemporaries)
125         FixItOpts.reset(new FixItRewriteToTemp());
126       else
127         FixItOpts.reset(new FixItRewriteInPlace());
128       FixItOpts->Silent = true;
129       FixItOpts->FixWhatYouCan = FEOpts.FixWhatYouCan;
130       FixItOpts->FixOnlyWarnings = FEOpts.FixOnlyWarnings;
131       FixItRewriter Rewriter(CI.getDiagnostics(), CI.getSourceManager(),
132                              CI.getLangOpts(), FixItOpts.get());
133       if (llvm::Error Err = FixAction->Execute()) {
134         // FIXME this drops the error on the floor.
135         consumeError(std::move(Err));
136         return false;
137       }
138 
139       err = Rewriter.WriteFixedFiles(&RewrittenFiles);
140 
141       FixAction->EndSourceFile();
142       CI.setSourceManager(nullptr);
143       CI.setFileManager(nullptr);
144     } else {
145       err = true;
146     }
147   }
148   if (err)
149     return false;
150   CI.getDiagnosticClient().clear();
151   CI.getDiagnostics().Reset();
152 
153   PreprocessorOptions &PPOpts = CI.getPreprocessorOpts();
154   PPOpts.RemappedFiles.insert(PPOpts.RemappedFiles.end(),
155                               RewrittenFiles.begin(), RewrittenFiles.end());
156   PPOpts.RemappedFilesKeepOriginalName = false;
157 
158   return true;
159 }
160 
161 #if CLANG_ENABLE_OBJC_REWRITER
162 
163 std::unique_ptr<ASTConsumer>
164 RewriteObjCAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
165   if (std::unique_ptr<raw_ostream> OS =
166           CI.createDefaultOutputFile(false, InFile, "cpp")) {
167     if (CI.getLangOpts().ObjCRuntime.isNonFragile())
168       return CreateModernObjCRewriter(std::string(InFile), std::move(OS),
169                                       CI.getDiagnostics(), CI.getLangOpts(),
170                                       CI.getDiagnosticOpts().NoRewriteMacros,
171                                       (CI.getCodeGenOpts().getDebugInfo() !=
172                                        llvm::codegenoptions::NoDebugInfo));
173     return CreateObjCRewriter(std::string(InFile), std::move(OS),
174                               CI.getDiagnostics(), CI.getLangOpts(),
175                               CI.getDiagnosticOpts().NoRewriteMacros);
176   }
177   return nullptr;
178 }
179 
180 #endif
181 
182 //===----------------------------------------------------------------------===//
183 // Preprocessor Actions
184 //===----------------------------------------------------------------------===//
185 
186 void RewriteMacrosAction::ExecuteAction() {
187   CompilerInstance &CI = getCompilerInstance();
188   std::unique_ptr<raw_ostream> OS =
189       CI.createDefaultOutputFile(/*Binary=*/true, getCurrentFileOrBufferName());
190   if (!OS) return;
191 
192   RewriteMacrosInInput(CI.getPreprocessor(), OS.get());
193 }
194 
195 void RewriteTestAction::ExecuteAction() {
196   CompilerInstance &CI = getCompilerInstance();
197   std::unique_ptr<raw_ostream> OS =
198       CI.createDefaultOutputFile(/*Binary=*/false, getCurrentFileOrBufferName());
199   if (!OS) return;
200 
201   DoRewriteTest(CI.getPreprocessor(), OS.get());
202 }
203 
204 class RewriteIncludesAction::RewriteImportsListener : public ASTReaderListener {
205   CompilerInstance &CI;
206   std::weak_ptr<raw_ostream> Out;
207 
208   llvm::DenseSet<const FileEntry*> Rewritten;
209 
210 public:
211   RewriteImportsListener(CompilerInstance &CI, std::shared_ptr<raw_ostream> Out)
212       : CI(CI), Out(Out) {}
213 
214   void visitModuleFile(StringRef Filename,
215                        serialization::ModuleKind Kind) override {
216     auto File = CI.getFileManager().getFile(Filename);
217     assert(File && "missing file for loaded module?");
218 
219     // Only rewrite each module file once.
220     if (!Rewritten.insert(*File).second)
221       return;
222 
223     serialization::ModuleFile *MF =
224         CI.getASTReader()->getModuleManager().lookup(*File);
225     assert(MF && "missing module file for loaded module?");
226 
227     // Not interested in PCH / preambles.
228     if (!MF->isModule())
229       return;
230 
231     auto OS = Out.lock();
232     assert(OS && "loaded module file after finishing rewrite action?");
233 
234     (*OS) << "#pragma clang module build ";
235     if (isValidAsciiIdentifier(MF->ModuleName))
236       (*OS) << MF->ModuleName;
237     else {
238       (*OS) << '"';
239       OS->write_escaped(MF->ModuleName);
240       (*OS) << '"';
241     }
242     (*OS) << '\n';
243 
244     // Rewrite the contents of the module in a separate compiler instance.
245     CompilerInstance Instance(CI.getPCHContainerOperations(),
246                               &CI.getModuleCache());
247     Instance.setInvocation(
248         std::make_shared<CompilerInvocation>(CI.getInvocation()));
249     Instance.createDiagnostics(
250         new ForwardingDiagnosticConsumer(CI.getDiagnosticClient()),
251         /*ShouldOwnClient=*/true);
252     Instance.getFrontendOpts().DisableFree = false;
253     Instance.getFrontendOpts().Inputs.clear();
254     Instance.getFrontendOpts().Inputs.emplace_back(
255         Filename, InputKind(Language::Unknown, InputKind::Precompiled));
256     Instance.getFrontendOpts().ModuleFiles.clear();
257     Instance.getFrontendOpts().ModuleMapFiles.clear();
258     // Don't recursively rewrite imports. We handle them all at the top level.
259     Instance.getPreprocessorOutputOpts().RewriteImports = false;
260 
261     llvm::CrashRecoveryContext().RunSafelyOnThread([&]() {
262       RewriteIncludesAction Action;
263       Action.OutputStream = OS;
264       Instance.ExecuteAction(Action);
265     });
266 
267     (*OS) << "#pragma clang module endbuild /*" << MF->ModuleName << "*/\n";
268   }
269 };
270 
271 bool RewriteIncludesAction::BeginSourceFileAction(CompilerInstance &CI) {
272   if (!OutputStream) {
273     OutputStream =
274         CI.createDefaultOutputFile(/*Binary=*/true, getCurrentFileOrBufferName());
275     if (!OutputStream)
276       return false;
277   }
278 
279   auto &OS = *OutputStream;
280 
281   // If we're preprocessing a module map, start by dumping the contents of the
282   // module itself before switching to the input buffer.
283   auto &Input = getCurrentInput();
284   if (Input.getKind().getFormat() == InputKind::ModuleMap) {
285     if (Input.isFile()) {
286       OS << "# 1 \"";
287       OS.write_escaped(Input.getFile());
288       OS << "\"\n";
289     }
290     getCurrentModule()->print(OS);
291     OS << "#pragma clang module contents\n";
292   }
293 
294   // If we're rewriting imports, set up a listener to track when we import
295   // module files.
296   if (CI.getPreprocessorOutputOpts().RewriteImports) {
297     CI.createASTReader();
298     CI.getASTReader()->addListener(
299         std::make_unique<RewriteImportsListener>(CI, OutputStream));
300   }
301 
302   return true;
303 }
304 
305 void RewriteIncludesAction::ExecuteAction() {
306   CompilerInstance &CI = getCompilerInstance();
307 
308   // If we're rewriting imports, emit the module build output first rather
309   // than switching back and forth (potentially in the middle of a line).
310   if (CI.getPreprocessorOutputOpts().RewriteImports) {
311     std::string Buffer;
312     llvm::raw_string_ostream OS(Buffer);
313 
314     RewriteIncludesInInput(CI.getPreprocessor(), &OS,
315                            CI.getPreprocessorOutputOpts());
316 
317     (*OutputStream) << OS.str();
318   } else {
319     RewriteIncludesInInput(CI.getPreprocessor(), OutputStream.get(),
320                            CI.getPreprocessorOutputOpts());
321   }
322 
323   OutputStream.reset();
324 }
325