[cfe-dev] Clang produces corrupt pch leading to crash

[Tobias Hahn]

Hi all,

I've run into (what I believe is) a memory bug with clang while producing a precompiled header. In short, under certain circumstances, clang will write a pch that causes a crash when trying to use this pch in a later compilation unit. 

Occasionally, while clang is compiling the pch, malloc complains that one of its checksums has been overwritten; while at other times, clang throws an error that a definition has a different exception specification than the declaration two lines above it (when both have no exception specification). Both these symptoms lead me to believe that somewhere clang overwrites memory.

I have stripped the code that reliably causes this crash down to a few hundred lines and have created a little script to reproduce the bug (details at http://llvm.org/bugs/show_bug.cgi?id=20026). I'm not sure, however, about your process for handling such bugs, which is why I'm cross-posting here. My main question is if there is anything else I could provide you with to help fixing this issue.

Thank you very much in advance!

Best,
Tobias 


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