This patch fixes broken preamble-skipping when the preamble region includes a byte order mark (BOM). Previously, parsing would fail if preamble PCH generation was enabled and a BOM was present.
This also fixes preamble invalidation when a BOM appears or disappears. This may seem to be an obscure edge case, but it happens regularly with IDEs that pass buffer overrides that never (or always) have a BOM, yet the underlying file from the initial parse that generated a PCH might (or might not) have a BOM.
I've included a test case for these scenarios.
Differential Revision: https://reviews.llvm.org/D37491
llvm-svn: 313796
Summary:
Two PrecompiledPreambles, used in parallel on separate threads,
could be writing preamble to the same temporary file.
Reviewers: bkramer, krasimir, klimek
Reviewed By: klimek
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D36529
llvm-svn: 310618
Cameron Desrochers