clang  3.9.0
Rewriter.cpp
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1 //===--- Rewriter.cpp - Code rewriting interface --------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the Rewriter class, which is used for code
11 // transformations.
12 //
13 //===----------------------------------------------------------------------===//
14 
16 #include "clang/Basic/Diagnostic.h"
19 #include "clang/Lex/Lexer.h"
20 #include "llvm/ADT/SmallString.h"
21 #include "llvm/Support/FileSystem.h"
22 #include "llvm/Support/raw_ostream.h"
23 using namespace clang;
24 
25 raw_ostream &RewriteBuffer::write(raw_ostream &os) const {
26  // Walk RewriteRope chunks efficiently using MoveToNextPiece() instead of the
27  // character iterator.
28  for (RopePieceBTreeIterator I = begin(), E = end(); I != E;
29  I.MoveToNextPiece())
30  os << I.piece();
31  return os;
32 }
33 
34 /// \brief Return true if this character is non-new-line whitespace:
35 /// ' ', '\\t', '\\f', '\\v', '\\r'.
36 static inline bool isWhitespaceExceptNL(unsigned char c) {
37  switch (c) {
38  case ' ':
39  case '\t':
40  case '\f':
41  case '\v':
42  case '\r':
43  return true;
44  default:
45  return false;
46  }
47 }
48 
49 void RewriteBuffer::RemoveText(unsigned OrigOffset, unsigned Size,
50  bool removeLineIfEmpty) {
51  // Nothing to remove, exit early.
52  if (Size == 0) return;
53 
54  unsigned RealOffset = getMappedOffset(OrigOffset, true);
55  assert(RealOffset+Size <= Buffer.size() && "Invalid location");
56 
57  // Remove the dead characters.
58  Buffer.erase(RealOffset, Size);
59 
60  // Add a delta so that future changes are offset correctly.
61  AddReplaceDelta(OrigOffset, -Size);
62 
63  if (removeLineIfEmpty) {
64  // Find the line that the remove occurred and if it is completely empty
65  // remove the line as well.
66 
67  iterator curLineStart = begin();
68  unsigned curLineStartOffs = 0;
69  iterator posI = begin();
70  for (unsigned i = 0; i != RealOffset; ++i) {
71  if (*posI == '\n') {
72  curLineStart = posI;
73  ++curLineStart;
74  curLineStartOffs = i + 1;
75  }
76  ++posI;
77  }
78 
79  unsigned lineSize = 0;
80  posI = curLineStart;
81  while (posI != end() && isWhitespaceExceptNL(*posI)) {
82  ++posI;
83  ++lineSize;
84  }
85  if (posI != end() && *posI == '\n') {
86  Buffer.erase(curLineStartOffs, lineSize + 1/* + '\n'*/);
87  AddReplaceDelta(curLineStartOffs, -(lineSize + 1/* + '\n'*/));
88  }
89  }
90 }
91 
92 void RewriteBuffer::InsertText(unsigned OrigOffset, StringRef Str,
93  bool InsertAfter) {
94 
95  // Nothing to insert, exit early.
96  if (Str.empty()) return;
97 
98  unsigned RealOffset = getMappedOffset(OrigOffset, InsertAfter);
99  Buffer.insert(RealOffset, Str.begin(), Str.end());
100 
101  // Add a delta so that future changes are offset correctly.
102  AddInsertDelta(OrigOffset, Str.size());
103 }
104 
105 /// ReplaceText - This method replaces a range of characters in the input
106 /// buffer with a new string. This is effectively a combined "remove+insert"
107 /// operation.
108 void RewriteBuffer::ReplaceText(unsigned OrigOffset, unsigned OrigLength,
109  StringRef NewStr) {
110  unsigned RealOffset = getMappedOffset(OrigOffset, true);
111  Buffer.erase(RealOffset, OrigLength);
112  Buffer.insert(RealOffset, NewStr.begin(), NewStr.end());
113  if (OrigLength != NewStr.size())
114  AddReplaceDelta(OrigOffset, NewStr.size() - OrigLength);
115 }
116 
117 
118 //===----------------------------------------------------------------------===//
119 // Rewriter class
120 //===----------------------------------------------------------------------===//
121 
122 /// getRangeSize - Return the size in bytes of the specified range if they
123 /// are in the same file. If not, this returns -1.
125  RewriteOptions opts) const {
126  if (!isRewritable(Range.getBegin()) ||
127  !isRewritable(Range.getEnd())) return -1;
128 
129  FileID StartFileID, EndFileID;
130  unsigned StartOff, EndOff;
131 
132  StartOff = getLocationOffsetAndFileID(Range.getBegin(), StartFileID);
133  EndOff = getLocationOffsetAndFileID(Range.getEnd(), EndFileID);
134 
135  if (StartFileID != EndFileID)
136  return -1;
137 
138  // If edits have been made to this buffer, the delta between the range may
139  // have changed.
140  std::map<FileID, RewriteBuffer>::const_iterator I =
141  RewriteBuffers.find(StartFileID);
142  if (I != RewriteBuffers.end()) {
143  const RewriteBuffer &RB = I->second;
144  EndOff = RB.getMappedOffset(EndOff, opts.IncludeInsertsAtEndOfRange);
145  StartOff = RB.getMappedOffset(StartOff, !opts.IncludeInsertsAtBeginOfRange);
146  }
147 
148 
149  // Adjust the end offset to the end of the last token, instead of being the
150  // start of the last token if this is a token range.
151  if (Range.isTokenRange())
152  EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
153 
154  return EndOff-StartOff;
155 }
156 
158  return getRangeSize(CharSourceRange::getTokenRange(Range), opts);
159 }
160 
161 
162 /// getRewrittenText - Return the rewritten form of the text in the specified
163 /// range. If the start or end of the range was unrewritable or if they are
164 /// in different buffers, this returns an empty string.
165 ///
166 /// Note that this method is not particularly efficient.
167 ///
168 std::string Rewriter::getRewrittenText(SourceRange Range) const {
169  if (!isRewritable(Range.getBegin()) ||
170  !isRewritable(Range.getEnd()))
171  return "";
172 
173  FileID StartFileID, EndFileID;
174  unsigned StartOff, EndOff;
175  StartOff = getLocationOffsetAndFileID(Range.getBegin(), StartFileID);
176  EndOff = getLocationOffsetAndFileID(Range.getEnd(), EndFileID);
177 
178  if (StartFileID != EndFileID)
179  return ""; // Start and end in different buffers.
180 
181  // If edits have been made to this buffer, the delta between the range may
182  // have changed.
183  std::map<FileID, RewriteBuffer>::const_iterator I =
184  RewriteBuffers.find(StartFileID);
185  if (I == RewriteBuffers.end()) {
186  // If the buffer hasn't been rewritten, just return the text from the input.
187  const char *Ptr = SourceMgr->getCharacterData(Range.getBegin());
188 
189  // Adjust the end offset to the end of the last token, instead of being the
190  // start of the last token.
191  EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
192  return std::string(Ptr, Ptr+EndOff-StartOff);
193  }
194 
195  const RewriteBuffer &RB = I->second;
196  EndOff = RB.getMappedOffset(EndOff, true);
197  StartOff = RB.getMappedOffset(StartOff);
198 
199  // Adjust the end offset to the end of the last token, instead of being the
200  // start of the last token.
201  EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
202 
203  // Advance the iterators to the right spot, yay for linear time algorithms.
204  RewriteBuffer::iterator Start = RB.begin();
205  std::advance(Start, StartOff);
207  std::advance(End, EndOff-StartOff);
208 
209  return std::string(Start, End);
210 }
211 
212 unsigned Rewriter::getLocationOffsetAndFileID(SourceLocation Loc,
213  FileID &FID) const {
214  assert(Loc.isValid() && "Invalid location");
215  std::pair<FileID,unsigned> V = SourceMgr->getDecomposedLoc(Loc);
216  FID = V.first;
217  return V.second;
218 }
219 
220 
221 /// getEditBuffer - Get or create a RewriteBuffer for the specified FileID.
222 ///
225  RewriteBuffers.lower_bound(FID);
226  if (I != RewriteBuffers.end() && I->first == FID)
227  return I->second;
228  I = RewriteBuffers.insert(I, std::make_pair(FID, RewriteBuffer()));
229 
230  StringRef MB = SourceMgr->getBufferData(FID);
231  I->second.Initialize(MB.begin(), MB.end());
232 
233  return I->second;
234 }
235 
236 /// InsertText - Insert the specified string at the specified location in the
237 /// original buffer.
238 bool Rewriter::InsertText(SourceLocation Loc, StringRef Str,
239  bool InsertAfter, bool indentNewLines) {
240  if (!isRewritable(Loc)) return true;
241  FileID FID;
242  unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);
243 
244  SmallString<128> indentedStr;
245  if (indentNewLines && Str.find('\n') != StringRef::npos) {
246  StringRef MB = SourceMgr->getBufferData(FID);
247 
248  unsigned lineNo = SourceMgr->getLineNumber(FID, StartOffs) - 1;
249  const SrcMgr::ContentCache *
250  Content = SourceMgr->getSLocEntry(FID).getFile().getContentCache();
251  unsigned lineOffs = Content->SourceLineCache[lineNo];
252 
253  // Find the whitespace at the start of the line.
254  StringRef indentSpace;
255  {
256  unsigned i = lineOffs;
257  while (isWhitespaceExceptNL(MB[i]))
258  ++i;
259  indentSpace = MB.substr(lineOffs, i-lineOffs);
260  }
261 
263  Str.split(lines, "\n");
264 
265  for (unsigned i = 0, e = lines.size(); i != e; ++i) {
266  indentedStr += lines[i];
267  if (i < e-1) {
268  indentedStr += '\n';
269  indentedStr += indentSpace;
270  }
271  }
272  Str = indentedStr.str();
273  }
274 
275  getEditBuffer(FID).InsertText(StartOffs, Str, InsertAfter);
276  return false;
277 }
278 
280  if (!isRewritable(Loc)) return true;
281  FileID FID;
282  unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);
283  RewriteOptions rangeOpts;
284  rangeOpts.IncludeInsertsAtBeginOfRange = false;
285  StartOffs += getRangeSize(SourceRange(Loc, Loc), rangeOpts);
286  getEditBuffer(FID).InsertText(StartOffs, Str, /*InsertAfter*/true);
287  return false;
288 }
289 
290 /// RemoveText - Remove the specified text region.
292  RewriteOptions opts) {
293  if (!isRewritable(Start)) return true;
294  FileID FID;
295  unsigned StartOffs = getLocationOffsetAndFileID(Start, FID);
296  getEditBuffer(FID).RemoveText(StartOffs, Length, opts.RemoveLineIfEmpty);
297  return false;
298 }
299 
300 /// ReplaceText - This method replaces a range of characters in the input
301 /// buffer with a new string. This is effectively a combined "remove/insert"
302 /// operation.
303 bool Rewriter::ReplaceText(SourceLocation Start, unsigned OrigLength,
304  StringRef NewStr) {
305  if (!isRewritable(Start)) return true;
306  FileID StartFileID;
307  unsigned StartOffs = getLocationOffsetAndFileID(Start, StartFileID);
308 
309  getEditBuffer(StartFileID).ReplaceText(StartOffs, OrigLength, NewStr);
310  return false;
311 }
312 
313 bool Rewriter::ReplaceText(SourceRange range, SourceRange replacementRange) {
314  if (!isRewritable(range.getBegin())) return true;
315  if (!isRewritable(range.getEnd())) return true;
316  if (replacementRange.isInvalid()) return true;
317  SourceLocation start = range.getBegin();
318  unsigned origLength = getRangeSize(range);
319  unsigned newLength = getRangeSize(replacementRange);
320  FileID FID;
321  unsigned newOffs = getLocationOffsetAndFileID(replacementRange.getBegin(),
322  FID);
323  StringRef MB = SourceMgr->getBufferData(FID);
324  return ReplaceText(start, origLength, MB.substr(newOffs, newLength));
325 }
326 
328  SourceLocation parentIndent) {
329  if (range.isInvalid()) return true;
330  if (!isRewritable(range.getBegin())) return true;
331  if (!isRewritable(range.getEnd())) return true;
332  if (!isRewritable(parentIndent)) return true;
333 
334  FileID StartFileID, EndFileID, parentFileID;
335  unsigned StartOff, EndOff, parentOff;
336 
337  StartOff = getLocationOffsetAndFileID(range.getBegin(), StartFileID);
338  EndOff = getLocationOffsetAndFileID(range.getEnd(), EndFileID);
339  parentOff = getLocationOffsetAndFileID(parentIndent, parentFileID);
340 
341  if (StartFileID != EndFileID || StartFileID != parentFileID)
342  return true;
343  if (StartOff > EndOff)
344  return true;
345 
346  FileID FID = StartFileID;
347  StringRef MB = SourceMgr->getBufferData(FID);
348 
349  unsigned parentLineNo = SourceMgr->getLineNumber(FID, parentOff) - 1;
350  unsigned startLineNo = SourceMgr->getLineNumber(FID, StartOff) - 1;
351  unsigned endLineNo = SourceMgr->getLineNumber(FID, EndOff) - 1;
352 
353  const SrcMgr::ContentCache *
354  Content = SourceMgr->getSLocEntry(FID).getFile().getContentCache();
355 
356  // Find where the lines start.
357  unsigned parentLineOffs = Content->SourceLineCache[parentLineNo];
358  unsigned startLineOffs = Content->SourceLineCache[startLineNo];
359 
360  // Find the whitespace at the start of each line.
361  StringRef parentSpace, startSpace;
362  {
363  unsigned i = parentLineOffs;
364  while (isWhitespaceExceptNL(MB[i]))
365  ++i;
366  parentSpace = MB.substr(parentLineOffs, i-parentLineOffs);
367 
368  i = startLineOffs;
369  while (isWhitespaceExceptNL(MB[i]))
370  ++i;
371  startSpace = MB.substr(startLineOffs, i-startLineOffs);
372  }
373  if (parentSpace.size() >= startSpace.size())
374  return true;
375  if (!startSpace.startswith(parentSpace))
376  return true;
377 
378  StringRef indent = startSpace.substr(parentSpace.size());
379 
380  // Indent the lines between start/end offsets.
381  RewriteBuffer &RB = getEditBuffer(FID);
382  for (unsigned lineNo = startLineNo; lineNo <= endLineNo; ++lineNo) {
383  unsigned offs = Content->SourceLineCache[lineNo];
384  unsigned i = offs;
385  while (isWhitespaceExceptNL(MB[i]))
386  ++i;
387  StringRef origIndent = MB.substr(offs, i-offs);
388  if (origIndent.startswith(startSpace))
389  RB.InsertText(offs, indent, /*InsertAfter=*/false);
390  }
391 
392  return false;
393 }
394 
395 namespace {
396 // A wrapper for a file stream that atomically overwrites the target.
397 //
398 // Creates a file output stream for a temporary file in the constructor,
399 // which is later accessible via getStream() if ok() return true.
400 // Flushes the stream and moves the temporary file to the target location
401 // in the destructor.
402 class AtomicallyMovedFile {
403 public:
404  AtomicallyMovedFile(DiagnosticsEngine &Diagnostics, StringRef Filename,
405  bool &AllWritten)
406  : Diagnostics(Diagnostics), Filename(Filename), AllWritten(AllWritten) {
407  TempFilename = Filename;
408  TempFilename += "-%%%%%%%%";
409  int FD;
410  if (llvm::sys::fs::createUniqueFile(TempFilename, FD, TempFilename)) {
411  AllWritten = false;
412  Diagnostics.Report(clang::diag::err_unable_to_make_temp)
413  << TempFilename;
414  } else {
415  FileStream.reset(new llvm::raw_fd_ostream(FD, /*shouldClose=*/true));
416  }
417  }
418 
419  ~AtomicallyMovedFile() {
420  if (!ok()) return;
421 
422  // Close (will also flush) theFileStream.
423  FileStream->close();
424  if (std::error_code ec = llvm::sys::fs::rename(TempFilename, Filename)) {
425  AllWritten = false;
426  Diagnostics.Report(clang::diag::err_unable_to_rename_temp)
427  << TempFilename << Filename << ec.message();
428  // If the remove fails, there's not a lot we can do - this is already an
429  // error.
430  llvm::sys::fs::remove(TempFilename);
431  }
432  }
433 
434  bool ok() { return (bool)FileStream; }
435  raw_ostream &getStream() { return *FileStream; }
436 
437 private:
438  DiagnosticsEngine &Diagnostics;
439  StringRef Filename;
440  SmallString<128> TempFilename;
441  std::unique_ptr<llvm::raw_fd_ostream> FileStream;
442  bool &AllWritten;
443 };
444 } // end anonymous namespace
445 
447  bool AllWritten = true;
448  for (buffer_iterator I = buffer_begin(), E = buffer_end(); I != E; ++I) {
449  const FileEntry *Entry =
450  getSourceMgr().getFileEntryForID(I->first);
451  AtomicallyMovedFile File(getSourceMgr().getDiagnostics(), Entry->getName(),
452  AllWritten);
453  if (File.ok()) {
454  I->second.write(File.getStream());
455  }
456  }
457  return !AllWritten;
458 }
SourceLocation getEnd() const
void insert(unsigned Offset, const char *Start, const char *End)
Definition: RewriteRope.h:196
bool IncreaseIndentation(CharSourceRange range, SourceLocation parentIndent)
Increase indentation for the lines between the given source range.
Definition: Rewriter.cpp:327
unsigned Length
SourceLocation getBegin() const
SourceManager & getSourceMgr() const
Definition: Rewriter.h:64
Defines the SourceManager interface.
static CharSourceRange getTokenRange(SourceRange R)
const SrcMgr::SLocEntry & getSLocEntry(FileID FID, bool *Invalid=nullptr) const
const char * getCharacterData(SourceLocation SL, bool *Invalid=nullptr) const
Return a pointer to the start of the specified location in the appropriate spelling MemoryBuffer...
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1124
bool RemoveText(SourceLocation Start, unsigned Length, RewriteOptions opts=RewriteOptions())
RemoveText - Remove the specified text region.
Definition: Rewriter.cpp:291
void erase(unsigned Offset, unsigned NumBytes)
Definition: RewriteRope.h:202
RewriteBuffer & getEditBuffer(FileID FID)
getEditBuffer - This is like getRewriteBufferFor, but always returns a buffer, and allows you to writ...
Definition: Rewriter.cpp:223
RewriteBuffer - As code is rewritten, SourceBuffer's from the original input with modifications get a...
Definition: RewriteBuffer.h:27
unsigned size() const
Definition: RewriteRope.h:184
StringRef getBufferData(FileID FID, bool *Invalid=nullptr) const
Return a StringRef to the source buffer data for the specified FileID.
bool ReplaceText(SourceLocation Start, unsigned OrigLength, StringRef NewStr)
ReplaceText - This method replaces a range of characters in the input buffer with a new string...
Definition: Rewriter.cpp:303
iterator end() const
Definition: RewriteBuffer.h:36
Concrete class used by the front-end to report problems and issues.
Definition: Diagnostic.h:135
detail::InMemoryDirectory::const_iterator I
buffer_iterator buffer_end()
Definition: Rewriter.h:178
iterator begin() const
Definition: RewriteBuffer.h:35
const FileEntry * getFileEntryForID(FileID FID) const
Returns the FileEntry record for the provided FileID.
StringRef Filename
Definition: Format.cpp:1194
const SmallVectorImpl< AnnotatedLine * >::const_iterator End
Represents a character-granular source range.
SourceLocation getEnd() const
static unsigned MeasureTokenLength(SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts)
MeasureTokenLength - Relex the token at the specified location and return its length in bytes in the ...
Definition: Lexer.cpp:406
void InsertText(unsigned OrigOffset, StringRef Str, bool InsertAfter=true)
InsertText - Insert some text at the specified point, where the offset in the buffer is specified rel...
Definition: Rewriter.cpp:92
bool overwriteChangedFiles()
overwriteChangedFiles - Save all changed files to disk.
Definition: Rewriter.cpp:446
bool isTokenRange() const
Return true if the end of this range specifies the start of the last token.
const char * getName() const
Definition: FileManager.h:85
void ReplaceText(unsigned OrigOffset, unsigned OrigLength, StringRef NewStr)
ReplaceText - This method replaces a range of characters in the input buffer with a new string...
Definition: Rewriter.cpp:108
Encodes a location in the source.
static bool isWhitespaceExceptNL(unsigned char c)
Return true if this character is non-new-line whitespace: ' ', '\t', '\f', '\v', '\r'.
Definition: Rewriter.cpp:36
const TemplateArgument * iterator
Definition: Type.h:4233
bool isValid() const
Return true if this is a valid SourceLocation object.
Cached information about one file (either on disk or in the virtual file system). ...
Definition: FileManager.h:53
bool InsertText(SourceLocation Loc, StringRef Str, bool InsertAfter=true, bool indentNewLines=false)
InsertText - Insert the specified string at the specified location in the original buffer...
Definition: Rewriter.cpp:238
bool RemoveLineIfEmpty
If true and removing some text leaves a blank line also remove the empty line (false by default)...
Definition: Rewriter.h:45
void RemoveText(unsigned OrigOffset, unsigned Size, bool removeLineIfEmpty=false)
RemoveText - Remove the specified text.
Definition: Rewriter.cpp:49
const FileInfo & getFile() const
SourceLocation getBegin() const
int getRangeSize(SourceRange Range, RewriteOptions opts=RewriteOptions()) const
getRangeSize - Return the size in bytes of the specified range if they are in the same file...
Definition: Rewriter.cpp:157
An opaque identifier used by SourceManager which refers to a source file (MemoryBuffer) along with it...
RopePieceBTreeIterator - This class provides read-only forward iteration over bytes that are in a Rop...
Definition: RewriteRope.h:88
const ContentCache * getContentCache() const
unsigned getLineNumber(FileID FID, unsigned FilePos, bool *Invalid=nullptr) const
Given a SourceLocation, return the spelling line number for the position indicated.
detail::InMemoryDirectory::const_iterator E
Defines the Diagnostic-related interfaces.
raw_ostream & write(raw_ostream &Stream) const
Write to Stream the result of applying all changes to the original buffer.
Definition: Rewriter.cpp:25
std::string getRewrittenText(SourceRange Range) const
getRewrittenText - Return the rewritten form of the text in the specified range.
Definition: Rewriter.cpp:168
bool IncludeInsertsAtBeginOfRange
Given a source range, true to include previous inserts at the beginning of the range as part of the r...
Definition: Rewriter.h:39
std::map< FileID, RewriteBuffer >::iterator buffer_iterator
Definition: Rewriter.h:53
bool isInvalid() const
buffer_iterator buffer_begin()
Definition: Rewriter.h:177
static bool isRewritable(SourceLocation Loc)
isRewritable - Return true if this location is a raw file location, which is rewritable.
Definition: Rewriter.h:69
Defines the Diagnostic IDs-related interfaces.
A trivial tuple used to represent a source range.
bool InsertTextAfterToken(SourceLocation Loc, StringRef Str)
Insert the specified string after the token in the specified location.
Definition: Rewriter.cpp:279
std::pair< FileID, unsigned > getDecomposedLoc(SourceLocation Loc) const
Decompose the specified location into a raw FileID + Offset pair.
bool IncludeInsertsAtEndOfRange
Given a source range, true to include previous inserts at the end of the range as part of the range i...
Definition: Rewriter.h:42