Ahmed Bougacha 8a19eb2a85 [ADT][SmallVector] Flip an assert comparison to avoid overflows yielding false-negatives. NFC. ... r221973 changed SmallVector::operator[] to use size_t instead of unsigned. Before that, on 64bit platforms, when a large index (say -1) was passed, truncating it to unsigned avoided an overflow when computing 'begin() + idx', and failed the range checking assertion, as expected. With r221973, idx isn't truncated, so the addition wraps to '(char*)begin() - 1', and doesn't fire anymore when it should have done so. This commit changes the comparison to instead compute 'end() - begin()' (i.e., 'size()'), which avoids potentially overflowing additions, and correctly triggers the assertion when values such as -1 are passed. Note that the problem already existed before that revision, on platforms where sizeof(size_t) == sizeof(unsigned). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225338 91177308-0d34-0410-b5e6-96231b3b80d8		2015-01-07 02:42:01 +00:00
..
llvm	[ADT][SmallVector] Flip an assert comparison to avoid overflows yielding false-negatives. NFC.	2015-01-07 02:42:01 +00:00
llvm-c	Finish removing DestroySource.	2014-12-23 19:16:45 +00:00