xref: /freebsd/contrib/llvm-project/clang/lib/ARCMigrate/FileRemapper.cpp (revision 62cfcf62f627e5093fb37026a6d8c98e4d2ef04c) 
1 //===--- FileRemapper.cpp - File Remapping Helper -------------------------===//
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/ARCMigrate/FileRemapper.h"
10 #include "clang/Basic/Diagnostic.h"
11 #include "clang/Basic/FileManager.h"
12 #include "clang/Lex/PreprocessorOptions.h"
13 #include "llvm/Support/FileSystem.h"
14 #include "llvm/Support/MemoryBuffer.h"
15 #include "llvm/Support/Path.h"
16 #include "llvm/Support/raw_ostream.h"
17 #include <fstream>
18 
19 using namespace clang;
20 using namespace arcmt;
21 
22 FileRemapper::FileRemapper() {
23   FileMgr.reset(new FileManager(FileSystemOptions()));
24 }
25 
26 FileRemapper::~FileRemapper() {
27   clear();
28 }
29 
30 void FileRemapper::clear(StringRef outputDir) {
31   for (MappingsTy::iterator
32          I = FromToMappings.begin(), E = FromToMappings.end(); I != E; ++I)
33     resetTarget(I->second);
34   FromToMappings.clear();
35   assert(ToFromMappings.empty());
36   if (!outputDir.empty()) {
37     std::string infoFile = getRemapInfoFile(outputDir);
38     llvm::sys::fs::remove(infoFile);
39   }
40 }
41 
42 std::string FileRemapper::getRemapInfoFile(StringRef outputDir) {
43   assert(!outputDir.empty());
44   SmallString<128> InfoFile = outputDir;
45   llvm::sys::path::append(InfoFile, "remap");
46   return InfoFile.str();
47 }
48 
49 bool FileRemapper::initFromDisk(StringRef outputDir, DiagnosticsEngine &Diag,
50                                 bool ignoreIfFilesChanged) {
51   std::string infoFile = getRemapInfoFile(outputDir);
52   return initFromFile(infoFile, Diag, ignoreIfFilesChanged);
53 }
54 
55 bool FileRemapper::initFromFile(StringRef filePath, DiagnosticsEngine &Diag,
56                                 bool ignoreIfFilesChanged) {
57   assert(FromToMappings.empty() &&
58          "initFromDisk should be called before any remap calls");
59   std::string infoFile = filePath;
60   if (!llvm::sys::fs::exists(infoFile))
61     return false;
62 
63   std::vector<std::pair<const FileEntry *, const FileEntry *> > pairs;
64 
65   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> fileBuf =
66       llvm::MemoryBuffer::getFile(infoFile);
67   if (!fileBuf)
68     return report("Error opening file: " + infoFile, Diag);
69 
70   SmallVector<StringRef, 64> lines;
71   fileBuf.get()->getBuffer().split(lines, "\n");
72 
73   for (unsigned idx = 0; idx+3 <= lines.size(); idx += 3) {
74     StringRef fromFilename = lines[idx];
75     unsigned long long timeModified;
76     if (lines[idx+1].getAsInteger(10, timeModified))
77       return report("Invalid file data: '" + lines[idx+1] + "' not a number",
78                     Diag);
79     StringRef toFilename = lines[idx+2];
80 
81     llvm::ErrorOr<const FileEntry *> origFE = FileMgr->getFile(fromFilename);
82     if (!origFE) {
83       if (ignoreIfFilesChanged)
84         continue;
85       return report("File does not exist: " + fromFilename, Diag);
86     }
87     llvm::ErrorOr<const FileEntry *> newFE = FileMgr->getFile(toFilename);
88     if (!newFE) {
89       if (ignoreIfFilesChanged)
90         continue;
91       return report("File does not exist: " + toFilename, Diag);
92     }
93 
94     if ((uint64_t)(*origFE)->getModificationTime() != timeModified) {
95       if (ignoreIfFilesChanged)
96         continue;
97       return report("File was modified: " + fromFilename, Diag);
98     }
99 
100     pairs.push_back(std::make_pair(*origFE, *newFE));
101   }
102 
103   for (unsigned i = 0, e = pairs.size(); i != e; ++i)
104     remap(pairs[i].first, pairs[i].second);
105 
106   return false;
107 }
108 
109 bool FileRemapper::flushToDisk(StringRef outputDir, DiagnosticsEngine &Diag) {
110   using namespace llvm::sys;
111 
112   if (fs::create_directory(outputDir))
113     return report("Could not create directory: " + outputDir, Diag);
114 
115   std::string infoFile = getRemapInfoFile(outputDir);
116   return flushToFile(infoFile, Diag);
117 }
118 
119 bool FileRemapper::flushToFile(StringRef outputPath, DiagnosticsEngine &Diag) {
120   using namespace llvm::sys;
121 
122   std::error_code EC;
123   std::string infoFile = outputPath;
124   llvm::raw_fd_ostream infoOut(infoFile, EC, llvm::sys::fs::OF_None);
125   if (EC)
126     return report(EC.message(), Diag);
127 
128   for (MappingsTy::iterator
129          I = FromToMappings.begin(), E = FromToMappings.end(); I != E; ++I) {
130 
131     const FileEntry *origFE = I->first;
132     SmallString<200> origPath = StringRef(origFE->getName());
133     fs::make_absolute(origPath);
134     infoOut << origPath << '\n';
135     infoOut << (uint64_t)origFE->getModificationTime() << '\n';
136 
137     if (const FileEntry *FE = I->second.dyn_cast<const FileEntry *>()) {
138       SmallString<200> newPath = StringRef(FE->getName());
139       fs::make_absolute(newPath);
140       infoOut << newPath << '\n';
141     } else {
142 
143       SmallString<64> tempPath;
144       int fd;
145       if (fs::createTemporaryFile(path::filename(origFE->getName()),
146                                   path::extension(origFE->getName()).drop_front(), fd,
147                                   tempPath))
148         return report("Could not create file: " + tempPath.str(), Diag);
149 
150       llvm::raw_fd_ostream newOut(fd, /*shouldClose=*/true);
151       llvm::MemoryBuffer *mem = I->second.get<llvm::MemoryBuffer *>();
152       newOut.write(mem->getBufferStart(), mem->getBufferSize());
153       newOut.close();
154 
155       auto newE = FileMgr->getFile(tempPath);
156       if (newE) {
157         remap(origFE, *newE);
158         infoOut << (*newE)->getName() << '\n';
159       }
160     }
161   }
162 
163   infoOut.close();
164   return false;
165 }
166 
167 bool FileRemapper::overwriteOriginal(DiagnosticsEngine &Diag,
168                                      StringRef outputDir) {
169   using namespace llvm::sys;
170 
171   for (MappingsTy::iterator
172          I = FromToMappings.begin(), E = FromToMappings.end(); I != E; ++I) {
173     const FileEntry *origFE = I->first;
174     assert(I->second.is<llvm::MemoryBuffer *>());
175     if (!fs::exists(origFE->getName()))
176       return report(StringRef("File does not exist: ") + origFE->getName(),
177                     Diag);
178 
179     std::error_code EC;
180     llvm::raw_fd_ostream Out(origFE->getName(), EC, llvm::sys::fs::OF_None);
181     if (EC)
182       return report(EC.message(), Diag);
183 
184     llvm::MemoryBuffer *mem = I->second.get<llvm::MemoryBuffer *>();
185     Out.write(mem->getBufferStart(), mem->getBufferSize());
186     Out.close();
187   }
188 
189   clear(outputDir);
190   return false;
191 }
192 
193 void FileRemapper::applyMappings(PreprocessorOptions &PPOpts) const {
194   for (MappingsTy::const_iterator
195          I = FromToMappings.begin(), E = FromToMappings.end(); I != E; ++I) {
196     if (const FileEntry *FE = I->second.dyn_cast<const FileEntry *>()) {
197       PPOpts.addRemappedFile(I->first->getName(), FE->getName());
198     } else {
199       llvm::MemoryBuffer *mem = I->second.get<llvm::MemoryBuffer *>();
200       PPOpts.addRemappedFile(I->first->getName(), mem);
201     }
202   }
203 
204   PPOpts.RetainRemappedFileBuffers = true;
205 }
206 
207 void FileRemapper::remap(StringRef filePath,
208                          std::unique_ptr<llvm::MemoryBuffer> memBuf) {
209   remap(getOriginalFile(filePath), std::move(memBuf));
210 }
211 
212 void FileRemapper::remap(const FileEntry *file,
213                          std::unique_ptr<llvm::MemoryBuffer> memBuf) {
214   assert(file);
215   Target &targ = FromToMappings[file];
216   resetTarget(targ);
217   targ = memBuf.release();
218 }
219 
220 void FileRemapper::remap(const FileEntry *file, const FileEntry *newfile) {
221   assert(file && newfile);
222   Target &targ = FromToMappings[file];
223   resetTarget(targ);
224   targ = newfile;
225   ToFromMappings[newfile] = file;
226 }
227 
228 const FileEntry *FileRemapper::getOriginalFile(StringRef filePath) {
229   const FileEntry *file = nullptr;
230   if (auto fileOrErr = FileMgr->getFile(filePath))
231     file = *fileOrErr;
232   // If we are updating a file that overridden an original file,
233   // actually update the original file.
234   llvm::DenseMap<const FileEntry *, const FileEntry *>::iterator
235     I = ToFromMappings.find(file);
236   if (I != ToFromMappings.end()) {
237     file = I->second;
238     assert(FromToMappings.find(file) != FromToMappings.end() &&
239            "Original file not in mappings!");
240   }
241   return file;
242 }
243 
244 void FileRemapper::resetTarget(Target &targ) {
245   if (!targ)
246     return;
247 
248   if (llvm::MemoryBuffer *oldmem = targ.dyn_cast<llvm::MemoryBuffer *>()) {
249     delete oldmem;
250   } else {
251     const FileEntry *toFE = targ.get<const FileEntry *>();
252     ToFromMappings.erase(toFE);
253   }
254 }
255 
256 bool FileRemapper::report(const Twine &err, DiagnosticsEngine &Diag) {
257   Diag.Report(Diag.getCustomDiagID(DiagnosticsEngine::Error, "%0"))
258       << err.str();
259   return true;
260 }
261