[cfe-dev] Can one control where clang writes .gcda coverage files? (to avoid crash)

[Sean McBride]

Hi all,

Is there any way to control the location clang writes .gcda coverage files?

I ask because I create nightly builds of my app on a build machine, and when I run the resulting app on a different machine it crashes like so:

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000068

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   libsystem_c.dylib             	0x00007fff8bd021ec flockfile + 15
1   libsystem_c.dylib             	0x00007fff8bce3c86 fwrite + 87
2   com.rogue-research.brainsight2	0x000000010285e366 llvm_gcda_start_file + 262
3   com.rogue-research.brainsight2	0x00000001016e9e80 __llvm_gcov_writeout + 16
4   dyld                          	0x00007fff6ecc015c ImageLoaderMachO::doTermination(ImageLoader::LinkContext const&) + 178
5   dyld                          	0x00007fff6ecb4591 dyld::runTerminators(void*) + 67
6   libsystem_c.dylib             	0x00007fff8bcad7c8 __cxa_finalize + 274
7   libsystem_c.dylib             	0x00007fff8bcad652 exit + 18
8   com.apple.AppKit              	0x00007fff88f0863e -[NSApplication terminate:] + 1767

Using Intruments, I see the path it's trying to access is a path on the build machine, which does not exist on my machine:

#	Caller	Function	FD	Path
1195	llvm_gcda_start_file	open_nocancel	-1	/Users/builder/rogue_nightly_build/working_copy/brainsight2/trunk/build/Brainsight2.build/Debug/Brainsight.build/Objects-normal/x86_64/RRPCAPointFilterCore.gcda

I consider this an llvm/clang bug; llvm_gcda_start_file() should at the very least handle the error gracefully, write no coverage, and not crash.  Do you concur?  Shall I file a bug?  Any workaround suggestions?

Thanks,

-- 
____________________________________________________________
Sean McBride, B. Eng                 sean at rogue-research.com
Rogue Research                        www.rogue-research.com 
Mac Software Developer              Montréal, Québec, Canada