This makes -Wunreachable-code work for programs containing SEH (except for
__finally, which is still missing for now).
__try is modeled like try (but simpler since it can only have a single __except
or __finally), __except is fairly similar to catch (but simpler, since it can't
contain declarations). __leave is implemented similarly to break / continue.
Use the existing addTryDispatchBlock infrastructure (which
FindUnreachableCode() in ReachableCode.cpp uses via cfg->try_blocks_begin()) to
mark things in the __except blocks as reachable.
Re-use TryTerminatedBlock. This means we add EH edges from calls to the __try
block, but not from all other statements. While this is incomplete, it matches
LLVM's SEH codegen support. Also, in practice, BuildOpts.AddEHEdges is always
false in practice from what I can tell, so we never even insert the call EH
edges either.
https://reviews.llvm.org/D36914
llvm-svn: 311561
Nico Weber