Peter Collingbourne ff87ac19c3 LTO: Fix a potential race condition in the caching API. ... After the call to sys::fs::exists succeeds, indicating a cache hit, we call AddFile and the client will open the file using the supplied path. If the client is using cache pruning, there is a potential race between the pruner and the client. To avoid this, change the caching API so that it provides a MemoryBuffer to the client, and have clients use that MemoryBuffer where possible. This scheme won't work with the gold plugin because the plugin API expects a file path. So we have the gold plugin use the buffer identifier as a path and live with the race for now. (Note that the gold plugin isn't actually affected by the problem at the moment because it doesn't support cache pruning.) This effectively reverts r279883 modulo the change to use the existing path in the gold plugin. Differential Revision: https://reviews.llvm.org/D31063 llvm-svn: 298020		2017-03-17 00:34:07 +00:00
..
llvm	LTO: Fix a potential race condition in the caching API.	2017-03-17 00:34:07 +00:00
llvm-c	[GVN] Initial check-in of a new global value numbering algorithm.	2016-12-22 16:03:48 +00:00