From b79d25ca9c3b895d8fdc88c3acefec1202ca9da3 Mon Sep 17 00:00:00 2001 From: Matt Beaumont-Gay Date: Tue, 12 Mar 2013 23:55:24 +0000 Subject: [PATCH] Don't crash if write_impl() leaves less buffer space available than expected. This was tickled by a Clang diagnostic; Clang test case to follow. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176911 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Support/raw_ostream.cpp | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp index f71abd3b244..da26a371a76 100644 --- a/lib/Support/raw_ostream.cpp +++ b/lib/Support/raw_ostream.cpp @@ -306,7 +306,12 @@ raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) { if (LLVM_UNLIKELY(OutBufCur == OutBufStart)) { size_t BytesToWrite = Size - (Size % NumBytes); write_impl(Ptr, BytesToWrite); - copy_to_buffer(Ptr + BytesToWrite, Size - BytesToWrite); + size_t BytesRemaining = Size - BytesToWrite; + if (BytesRemaining > size_t(OutBufEnd - OutBufCur)) { + // Too much left over to copy into our buffer. + return write(Ptr + BytesToWrite, BytesRemaining); + } + copy_to_buffer(Ptr + BytesToWrite, BytesRemaining); return *this; }