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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/Support/raw_ostream.h"
+using namespace clang;
+
+llvm::raw_ostream &RewriteBuffer::write(llvm::raw_ostream &os) const {
+ // FIXME: eliminate the copy by writing out each chunk at a time
+ os << std::string(begin(), end());
+ return os;
+}
+
+void RewriteBuffer::RemoveText(unsigned OrigOffset, unsigned Size) {
+ // 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);
+}
+
+void RewriteBuffer::InsertText(unsigned OrigOffset, const llvm::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,
+ const llvm::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(SourceRange Range) 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, 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);
+
+ return EndOff-StartOff;
+}
+
+/// 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()));
+
+ llvm::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, const llvm::StringRef &Str,
+ bool InsertAfter) {
+ if (!isRewritable(Loc)) return true;
+ FileID FID;
+ unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);
+ getEditBuffer(FID).InsertText(StartOffs, Str, InsertAfter);
+ return false;
+}
+
+/// RemoveText - Remove the specified text region.
+bool Rewriter::RemoveText(SourceLocation Start, unsigned Length) {
+ if (!isRewritable(Start)) return true;
+ FileID FID;
+ unsigned StartOffs = getLocationOffsetAndFileID(Start, FID);
+ getEditBuffer(FID).RemoveText(StartOffs, Length);
+ 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,
+ const llvm::StringRef &NewStr) {
+ if (!isRewritable(Start)) return true;
+ FileID StartFileID;
+ unsigned StartOffs = getLocationOffsetAndFileID(Start, StartFileID);
+
+ getEditBuffer(StartFileID).ReplaceText(StartOffs, OrigLength, NewStr);
+ return false;
+}
+
+/// 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;
+}
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