Tim Deegan 4eb880e1b5 Implement DWARF DW_CFA_val_expression for x86_64 ... Ubuntu's libc-bin (2.15-0ubuntu20.2) on x86_64 uses DW_CFA_val_expression in describing the pthread spinlock operations __lll_unlock_wake() and __lll_lock_wait(). libunwind 1.1 doesn't understand that opcode and so backtraces from those operations are truncated. This changeset adds basic support for it, by adding a new type to dwarf_loc_t that describes the register's actual contents rather than its location. I've only implemented the new type for x86_64, and stubbed it out for all other architectures -- it looks like a lot of that code is duplicated so oughtn't to be that hard, but I don't have test cases for them. Tested that DW_CFA_val_expression works on x86_64 (by using https://code.google.com/p/gperftools/ on a lock-heavy program). Build-tested on x86, x86_64 and arm. The unit tests don't pass for me on any of those archs, but this cset doesn't break anything that was passing before. Signed-off-by: Tim Deegan <tjd@phlegethon.org>		2014-02-08 20:19:20 -08:00
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dwarf-config.h	Handle register nums > 16 on x86_64	2011-06-18 20:48:49 -07:00
jmpbuf.h	Remove extra empty line	2010-03-13 18:33:22 +02:00
libunwind_i.h	Implement DWARF DW_CFA_val_expression for x86_64	2014-02-08 20:19:20 -08:00