From a0978c24829dfd552d38fc3bae2b86e18bb90d49 Mon Sep 17 00:00:00 2001 From: Eli Friedman Date: Mon, 18 May 2009 13:56:52 +0000 Subject: [PATCH] Fix for PR2386: distinguish between insertion and replacements in the delta tree. The issue is roughly a conflict in ReplaceText between two kinds of uses. One, it should be possible to replace a replacement: for example, the ObjC rewriter calls ReplaceStmt for an expression, then replaces the resulting expression with another expression. Two, it should be possible to replace text that already has text inserted before it: for example, the HTML rewriter inserts a bunch of tags at the beginning of the line, then tries to escape the first character on the line. This patch distinguishes the two cases by storing the deltas separately; essentially, replacements and insertions no longer interfere with each other. Another possibility would be to add some sort of flag to ReplaceText, but this seems a bit more intuitive and flexible. There are a few downsides to the current solution: one is that there isn't any way to remove/replace an insertion without touching additional surrounding text; if such an operation turns out to be useful, an additional method or flag can be added. Another is that an insertion and replacing a string of length zero are distinct operations; I'm not sure how to resolve this, or whether it will be confusing in practice. This is relatively sensitive code, so please test and tell me if anything breaks. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@72000 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/clang/Rewrite/Rewriter.h | 16 +++++++++++----- lib/Rewrite/Rewriter.cpp | 8 ++++---- test/Misc/emit-html-insert.c | 4 ++++ 3 files changed, 19 insertions(+), 9 deletions(-) create mode 100644 test/Misc/emit-html-insert.c diff --git a/include/clang/Rewrite/Rewriter.h b/include/clang/Rewrite/Rewriter.h index afa018d9cb..c3ee0175c3 100644 --- a/include/clang/Rewrite/Rewriter.h +++ b/include/clang/Rewrite/Rewriter.h @@ -102,13 +102,19 @@ private: // Methods only usable by Rewriter. /// inserted text at the position. unsigned getMappedOffset(unsigned OrigOffset, bool AfterInserts = false) const{ - return Deltas.getDeltaAt(OrigOffset+AfterInserts)+OrigOffset; + return Deltas.getDeltaAt(2*OrigOffset+AfterInserts)+OrigOffset; } - /// AddDelta - When a change is made that shifts around the text buffer, this - /// method is used to record that info. - void AddDelta(unsigned OrigOffset, int Change) { - return Deltas.AddDelta(OrigOffset, Change); + /// AddInsertDelta - When an insertion is made at a position, this + /// method is used to record that information. + void AddInsertDelta(unsigned OrigOffset, int Change) { + return Deltas.AddDelta(2*OrigOffset, Change); + } + + /// AddReplaceDelta - When a replacement/deletion is made at a position, this + /// method is used to record that information. + void AddReplaceDelta(unsigned OrigOffset, int Change) { + return Deltas.AddDelta(2*OrigOffset+1, Change); } }; diff --git a/lib/Rewrite/Rewriter.cpp b/lib/Rewrite/Rewriter.cpp index 805c61baed..d81c38d6a4 100644 --- a/lib/Rewrite/Rewriter.cpp +++ b/lib/Rewrite/Rewriter.cpp @@ -31,7 +31,7 @@ void RewriteBuffer::RemoveText(unsigned OrigOffset, unsigned Size) { Buffer.erase(RealOffset, Size); // Add a delta so that future changes are offset correctly. - AddDelta(OrigOffset, -Size); + AddReplaceDelta(OrigOffset, -Size); } void RewriteBuffer::InsertText(unsigned OrigOffset, @@ -45,7 +45,7 @@ void RewriteBuffer::InsertText(unsigned OrigOffset, Buffer.insert(RealOffset, StrData, StrData+StrLen); // Add a delta so that future changes are offset correctly. - AddDelta(OrigOffset, StrLen); + AddInsertDelta(OrigOffset, StrLen); } /// ReplaceText - This method replaces a range of characters in the input @@ -53,11 +53,11 @@ void RewriteBuffer::InsertText(unsigned OrigOffset, /// operation. void RewriteBuffer::ReplaceText(unsigned OrigOffset, unsigned OrigLength, const char *NewStr, unsigned NewLength) { - unsigned RealOffset = getMappedOffset(OrigOffset, false); + unsigned RealOffset = getMappedOffset(OrigOffset, true); Buffer.erase(RealOffset, OrigLength); Buffer.insert(RealOffset, NewStr, NewStr+NewLength); if (OrigLength != NewLength) - AddDelta(OrigOffset, NewLength-OrigLength); + AddReplaceDelta(OrigOffset, NewLength-OrigLength); } diff --git a/test/Misc/emit-html-insert.c b/test/Misc/emit-html-insert.c new file mode 100644 index 0000000000..ac6b519a3a --- /dev/null +++ b/test/Misc/emit-html-insert.c @@ -0,0 +1,4 @@ +// RUN: clang-cc %s -emit-html -o - | grep ">< 10; }" + +int a(int x) { return x +< 10; } -- 2.50.1