Merge branch 'master' of ssh://bitbucket.org/czan/honours

1 files changed, 414 insertions, 0 deletions

diff --git a/clang/lib/Rewrite/Rewriter.cpp b/clang/lib/Rewrite/Rewriter.cpp
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+//===--- Rewriter.cpp - Code rewriting interface --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the Rewriter class, which is used for code
+//  transformations.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Rewrite/Rewriter.h"
+#include "clang/AST/Stmt.h"
+#include "clang/AST/Decl.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Basic/SourceManager.h"
+#include "llvm/ADT/SmallString.h"
+using namespace clang;
+
+raw_ostream &RewriteBuffer::write(raw_ostream &os) const {
+  // FIXME: eliminate the copy by writing out each chunk at a time
+  os << std::string(begin(), end());
+  return os;
+}
+
+/// \brief Return true if this character is non-new-line whitespace:
+/// ' ', '\t', '\f', '\v', '\r'.
+static inline bool isWhitespace(unsigned char c) {
+  switch (c) {
+  case ' ':
+  case '\t':
+  case '\f':
+  case '\v':
+  case '\r':
+    return true;
+  default:
+    return false;
+  }
+}
+
+void RewriteBuffer::RemoveText(unsigned OrigOffset, unsigned Size,
+                               bool removeLineIfEmpty) {
+  // Nothing to remove, exit early.
+  if (Size == 0) return;
+
+  unsigned RealOffset = getMappedOffset(OrigOffset, true);
+  assert(RealOffset+Size < Buffer.size() && "Invalid location");
+
+  // Remove the dead characters.
+  Buffer.erase(RealOffset, Size);
+
+  // Add a delta so that future changes are offset correctly.
+  AddReplaceDelta(OrigOffset, -Size);
+
+  if (removeLineIfEmpty) {
+    // Find the line that the remove occurred and if it is completely empty
+    // remove the line as well.
+
+    iterator curLineStart = begin();
+    unsigned curLineStartOffs = 0;
+    iterator posI = begin();
+    for (unsigned i = 0; i != RealOffset; ++i) {
+      if (*posI == '\n') {
+        curLineStart = posI;
+        ++curLineStart;
+        curLineStartOffs = i + 1;
+      }
+      ++posI;
+    }
+  
+    unsigned lineSize = 0;
+    posI = curLineStart;
+    while (posI != end() && isWhitespace(*posI)) {
+      ++posI;
+      ++lineSize;
+    }
+    if (posI != end() && *posI == '\n') {
+      Buffer.erase(curLineStartOffs, lineSize + 1/* + '\n'*/);
+      AddReplaceDelta(curLineStartOffs, -(lineSize + 1/* + '\n'*/));
+    }
+  }
+}
+
+void RewriteBuffer::InsertText(unsigned OrigOffset, StringRef Str,
+                               bool InsertAfter) {
+
+  // Nothing to insert, exit early.
+  if (Str.empty()) return;
+
+  unsigned RealOffset = getMappedOffset(OrigOffset, InsertAfter);
+  Buffer.insert(RealOffset, Str.begin(), Str.end());
+
+  // Add a delta so that future changes are offset correctly.
+  AddInsertDelta(OrigOffset, Str.size());
+}
+
+/// ReplaceText - This method replaces a range of characters in the input
+/// buffer with a new string.  This is effectively a combined "remove+insert"
+/// operation.
+void RewriteBuffer::ReplaceText(unsigned OrigOffset, unsigned OrigLength,
+                                StringRef NewStr) {
+  unsigned RealOffset = getMappedOffset(OrigOffset, true);
+  Buffer.erase(RealOffset, OrigLength);
+  Buffer.insert(RealOffset, NewStr.begin(), NewStr.end());
+  if (OrigLength != NewStr.size())
+    AddReplaceDelta(OrigOffset, NewStr.size() - OrigLength);
+}
+
+
+//===----------------------------------------------------------------------===//
+// Rewriter class
+//===----------------------------------------------------------------------===//
+
+/// getRangeSize - Return the size in bytes of the specified range if they
+/// are in the same file.  If not, this returns -1.
+int Rewriter::getRangeSize(const CharSourceRange &Range,
+                           RewriteOptions opts) const {
+  if (!isRewritable(Range.getBegin()) ||
+      !isRewritable(Range.getEnd())) return -1;
+
+  FileID StartFileID, EndFileID;
+  unsigned StartOff, EndOff;
+
+  StartOff = getLocationOffsetAndFileID(Range.getBegin(), StartFileID);
+  EndOff   = getLocationOffsetAndFileID(Range.getEnd(), EndFileID);
+
+  if (StartFileID != EndFileID)
+    return -1;
+
+  // If edits have been made to this buffer, the delta between the range may
+  // have changed.
+  std::map<FileID, RewriteBuffer>::const_iterator I =
+    RewriteBuffers.find(StartFileID);
+  if (I != RewriteBuffers.end()) {
+    const RewriteBuffer &RB = I->second;
+    EndOff = RB.getMappedOffset(EndOff, opts.IncludeInsertsAtEndOfRange);
+    StartOff = RB.getMappedOffset(StartOff, !opts.IncludeInsertsAtBeginOfRange);
+  }
+
+
+  // Adjust the end offset to the end of the last token, instead of being the
+  // start of the last token if this is a token range.
+  if (Range.isTokenRange())
+    EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
+
+  return EndOff-StartOff;
+}
+
+int Rewriter::getRangeSize(SourceRange Range, RewriteOptions opts) const {
+  return getRangeSize(CharSourceRange::getTokenRange(Range), opts);
+}
+
+
+/// getRewrittenText - Return the rewritten form of the text in the specified
+/// range.  If the start or end of the range was unrewritable or if they are
+/// in different buffers, this returns an empty string.
+///
+/// Note that this method is not particularly efficient.
+///
+std::string Rewriter::getRewrittenText(SourceRange Range) const {
+  if (!isRewritable(Range.getBegin()) ||
+      !isRewritable(Range.getEnd()))
+    return "";
+
+  FileID StartFileID, EndFileID;
+  unsigned StartOff, EndOff;
+  StartOff = getLocationOffsetAndFileID(Range.getBegin(), StartFileID);
+  EndOff   = getLocationOffsetAndFileID(Range.getEnd(), EndFileID);
+
+  if (StartFileID != EndFileID)
+    return ""; // Start and end in different buffers.
+
+  // If edits have been made to this buffer, the delta between the range may
+  // have changed.
+  std::map<FileID, RewriteBuffer>::const_iterator I =
+    RewriteBuffers.find(StartFileID);
+  if (I == RewriteBuffers.end()) {
+    // If the buffer hasn't been rewritten, just return the text from the input.
+    const char *Ptr = SourceMgr->getCharacterData(Range.getBegin());
+
+    // Adjust the end offset to the end of the last token, instead of being the
+    // start of the last token.
+    EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
+    return std::string(Ptr, Ptr+EndOff-StartOff);
+  }
+
+  const RewriteBuffer &RB = I->second;
+  EndOff = RB.getMappedOffset(EndOff, true);
+  StartOff = RB.getMappedOffset(StartOff);
+
+  // Adjust the end offset to the end of the last token, instead of being the
+  // start of the last token.
+  EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
+
+  // Advance the iterators to the right spot, yay for linear time algorithms.
+  RewriteBuffer::iterator Start = RB.begin();
+  std::advance(Start, StartOff);
+  RewriteBuffer::iterator End = Start;
+  std::advance(End, EndOff-StartOff);
+
+  return std::string(Start, End);
+}
+
+unsigned Rewriter::getLocationOffsetAndFileID(SourceLocation Loc,
+                                              FileID &FID) const {
+  assert(Loc.isValid() && "Invalid location");
+  std::pair<FileID,unsigned> V = SourceMgr->getDecomposedLoc(Loc);
+  FID = V.first;
+  return V.second;
+}
+
+
+/// getEditBuffer - Get or create a RewriteBuffer for the specified FileID.
+///
+RewriteBuffer &Rewriter::getEditBuffer(FileID FID) {
+  std::map<FileID, RewriteBuffer>::iterator I =
+    RewriteBuffers.lower_bound(FID);
+  if (I != RewriteBuffers.end() && I->first == FID)
+    return I->second;
+  I = RewriteBuffers.insert(I, std::make_pair(FID, RewriteBuffer()));
+
+  StringRef MB = SourceMgr->getBufferData(FID);
+  I->second.Initialize(MB.begin(), MB.end());
+
+  return I->second;
+}
+
+/// InsertText - Insert the specified string at the specified location in the
+/// original buffer.
+bool Rewriter::InsertText(SourceLocation Loc, StringRef Str,
+                          bool InsertAfter, bool indentNewLines) {
+  if (!isRewritable(Loc)) return true;
+  FileID FID;
+  unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);
+
+  SmallString<128> indentedStr;
+  if (indentNewLines && Str.find('\n') != StringRef::npos) {
+    StringRef MB = SourceMgr->getBufferData(FID);
+
+    unsigned lineNo = SourceMgr->getLineNumber(FID, StartOffs) - 1;
+    const SrcMgr::ContentCache *
+        Content = SourceMgr->getSLocEntry(FID).getFile().getContentCache();
+    unsigned lineOffs = Content->SourceLineCache[lineNo];
+
+    // Find the whitespace at the start of the line.
+    StringRef indentSpace;
+    {
+      unsigned i = lineOffs;
+      while (isWhitespace(MB[i]))
+        ++i;
+      indentSpace = MB.substr(lineOffs, i-lineOffs);
+    }
+
+    SmallVector<StringRef, 4> lines;
+    Str.split(lines, "\n");
+
+    for (unsigned i = 0, e = lines.size(); i != e; ++i) {
+      indentedStr += lines[i];
+      if (i < e-1) {
+        indentedStr += '\n';
+        indentedStr += indentSpace;
+      }
+    }
+    Str = indentedStr.str();
+  }
+
+  getEditBuffer(FID).InsertText(StartOffs, Str, InsertAfter);
+  return false;
+}
+
+bool Rewriter::InsertTextAfterToken(SourceLocation Loc, StringRef Str) {
+  if (!isRewritable(Loc)) return true;
+  FileID FID;
+  unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);
+  RewriteOptions rangeOpts;
+  rangeOpts.IncludeInsertsAtBeginOfRange = false;
+  StartOffs += getRangeSize(SourceRange(Loc, Loc), rangeOpts);
+  getEditBuffer(FID).InsertText(StartOffs, Str, /*InsertAfter*/true);
+  return false;
+}
+
+/// RemoveText - Remove the specified text region.
+bool Rewriter::RemoveText(SourceLocation Start, unsigned Length,
+                          RewriteOptions opts) {
+  if (!isRewritable(Start)) return true;
+  FileID FID;
+  unsigned StartOffs = getLocationOffsetAndFileID(Start, FID);
+  getEditBuffer(FID).RemoveText(StartOffs, Length, opts.RemoveLineIfEmpty);
+  return false;
+}
+
+/// ReplaceText - This method replaces a range of characters in the input
+/// buffer with a new string.  This is effectively a combined "remove/insert"
+/// operation.
+bool Rewriter::ReplaceText(SourceLocation Start, unsigned OrigLength,
+                           StringRef NewStr) {
+  if (!isRewritable(Start)) return true;
+  FileID StartFileID;
+  unsigned StartOffs = getLocationOffsetAndFileID(Start, StartFileID);
+
+  getEditBuffer(StartFileID).ReplaceText(StartOffs, OrigLength, NewStr);
+  return false;
+}
+
+bool Rewriter::ReplaceText(SourceRange range, SourceRange replacementRange) {
+  if (!isRewritable(range.getBegin())) return true;
+  if (!isRewritable(range.getEnd())) return true;
+  if (replacementRange.isInvalid()) return true;
+  SourceLocation start = range.getBegin();
+  unsigned origLength = getRangeSize(range);
+  unsigned newLength = getRangeSize(replacementRange);
+  FileID FID;
+  unsigned newOffs = getLocationOffsetAndFileID(replacementRange.getBegin(),
+                                                FID);
+  StringRef MB = SourceMgr->getBufferData(FID);
+  return ReplaceText(start, origLength, MB.substr(newOffs, newLength));
+}
+
+/// ReplaceStmt - This replaces a Stmt/Expr with another, using the pretty
+/// printer to generate the replacement code.  This returns true if the input
+/// could not be rewritten, or false if successful.
+bool Rewriter::ReplaceStmt(Stmt *From, Stmt *To) {
+  // Measaure the old text.
+  int Size = getRangeSize(From->getSourceRange());
+  if (Size == -1)
+    return true;
+
+  // Get the new text.
+  std::string SStr;
+  llvm::raw_string_ostream S(SStr);
+  To->printPretty(S, 0, PrintingPolicy(*LangOpts));
+  const std::string &Str = S.str();
+
+  ReplaceText(From->getLocStart(), Size, Str);
+  return false;
+}
+
+std::string Rewriter::ConvertToString(Stmt *From) {
+  std::string SStr;
+  llvm::raw_string_ostream S(SStr);
+  From->printPretty(S, 0, PrintingPolicy(*LangOpts));
+  return S.str();
+}
+
+bool Rewriter::IncreaseIndentation(CharSourceRange range,
+                                   SourceLocation parentIndent) {
+  if (range.isInvalid()) return true;
+  if (!isRewritable(range.getBegin())) return true;
+  if (!isRewritable(range.getEnd())) return true;
+  if (!isRewritable(parentIndent)) return true;
+
+  FileID StartFileID, EndFileID, parentFileID;
+  unsigned StartOff, EndOff, parentOff;
+
+  StartOff = getLocationOffsetAndFileID(range.getBegin(), StartFileID);
+  EndOff   = getLocationOffsetAndFileID(range.getEnd(), EndFileID);
+  parentOff = getLocationOffsetAndFileID(parentIndent, parentFileID);
+
+  if (StartFileID != EndFileID || StartFileID != parentFileID)
+    return true;
+  if (StartOff > EndOff)
+    return true;
+
+  FileID FID = StartFileID;
+  StringRef MB = SourceMgr->getBufferData(FID);
+
+  unsigned parentLineNo = SourceMgr->getLineNumber(FID, parentOff) - 1;
+  unsigned startLineNo = SourceMgr->getLineNumber(FID, StartOff) - 1;
+  unsigned endLineNo = SourceMgr->getLineNumber(FID, EndOff) - 1;
+  
+  const SrcMgr::ContentCache *
+      Content = SourceMgr->getSLocEntry(FID).getFile().getContentCache();
+  
+  // Find where the lines start.
+  unsigned parentLineOffs = Content->SourceLineCache[parentLineNo];
+  unsigned startLineOffs = Content->SourceLineCache[startLineNo];
+
+  // Find the whitespace at the start of each line.
+  StringRef parentSpace, startSpace;
+  {
+    unsigned i = parentLineOffs;
+    while (isWhitespace(MB[i]))
+      ++i;
+    parentSpace = MB.substr(parentLineOffs, i-parentLineOffs);
+
+    i = startLineOffs;
+    while (isWhitespace(MB[i]))
+      ++i;
+    startSpace = MB.substr(startLineOffs, i-startLineOffs);
+  }
+  if (parentSpace.size() >= startSpace.size())
+    return true;
+  if (!startSpace.startswith(parentSpace))
+    return true;
+
+  StringRef indent = startSpace.substr(parentSpace.size());
+
+  // Indent the lines between start/end offsets.
+  RewriteBuffer &RB = getEditBuffer(FID);
+  for (unsigned lineNo = startLineNo; lineNo <= endLineNo; ++lineNo) {
+    unsigned offs = Content->SourceLineCache[lineNo];
+    unsigned i = offs;
+    while (isWhitespace(MB[i]))
+      ++i;
+    StringRef origIndent = MB.substr(offs, i-offs);
+    if (origIndent.startswith(startSpace))
+      RB.InsertText(offs, indent, /*InsertAfter=*/false);
+  }
+
+  return false;
+}