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Diffstat (limited to 'contrib/llvm/tools/clang/lib/Rewrite/Rewriter.cpp')
-rw-r--r-- | contrib/llvm/tools/clang/lib/Rewrite/Rewriter.cpp | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Rewrite/Rewriter.cpp b/contrib/llvm/tools/clang/lib/Rewrite/Rewriter.cpp new file mode 100644 index 0000000..376678a --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Rewrite/Rewriter.cpp @@ -0,0 +1,230 @@ +//===--- 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; +} |