[lldb-dev] sigtrap (but only in the debugger)

Jim Ingham jingham at apple.com
Mon Nov 12 10:35:26 PST 2012


This is the place where we put a breakpoint to notify ourselves when shared libraries are added to the program.  The breakpoint there should be handled by the Mac OS X dyld Shared Library plugin.  The breakpoint is set in:

DynamicLoaderMacOSXDYLD::SetNotificationBreakpoint

and a callback is installed that should read in the new shared libraries and then continue on:

DynamicLoaderMacOSXDYLD::NotifyBreakpointHit

Maybe there is some error here such that the NotifyBreakpointHit is not continuing the target (which it does by returning "false".)  You should see if you are hitting the callback at all, and if so step through what's going on there to see what's up.

Jim


On Nov 12, 2012, at 3:04 AM, Carlo Kok <ck at remobjects.com> wrote:

> When using lldb and clicking the main menu on osx I get a sigtrap breakpoint in lldb:
> 
> 
> Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
> 0   dyld                          	0x00007fff67a0e6e5 gdb_image_notifier(dyld_image_mode, unsigned int, dyld_image_info const*) + 0
> 1   dyld                          	0x00007fff67a059b4 dyld::notifyBatchPartial(dyld_image_states, bool, char const* (*)(dyld_image_states, unsigned int, dyld_image_info const*)) + 791
> 2   dyld                          	0x00007fff67a0ffc4 ImageLoader::link(ImageLoader::LinkContext const&, bool, bool, ImageLoader::RPathChain const&) + 84
> 3   dyld                          	0x00007fff67a05ce4 dyld::link(ImageLoader*, bool, ImageLoader::RPathChain const&) + 547
> 
> 
> Exception Type:  EXC_BREAKPOINT (SIGTRAP)
> Exception Codes: 0x0000000000000002, 0x0000000000000000
> 
> It works outside the debugger. Given the name of that method it sounds like something LLDB should be dealing with internally. What could this be and how do I get around it?
> 
> (full crash log attached)
> <crash.txt>_______________________________________________
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