https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66503
Bug ID: 66503 Summary: missing DW_AT_abstract_origin for cross-unit call sites Product: gcc Version: 5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: debug Assignee: unassigned at gcc dot gnu.org Reporter: derodat at adacore dot com Target Milestone: --- Created attachment 35754 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35754&action=edit C reproducer With the recent work for PR debug/65549, we observed a regression in the generated debugging information. Take the attached reproducer, build it and look at the output DWARF: $ gcc -c -O1 -g foo.c $ objdump --dwarf=info foo.o [...] <2><4e>: Abbrev Number: 3 (DW_TAG_GNU_call_site) <4f> DW_AT_low_pc : 0x9 <2><57>: Abbrev Number: 0 There is no DW_AT_abstract_origin attribute anymore, whereas there used to be one. On PowerPC with -mlongcall, for instance, call instructions are indirect and we (at AdaCore) rely on this attribute to determine what function is actually called (it's easier this way than interpreting machine code...). The DWARF proposal for call sites also say debuggers should be able to use this attribute (to build virtual call stacks in the presence of tail calls), but I could not observe this in practice with GDB. (Excepts from the <https://gcc.gnu.org/ml/gcc-patches/2015-06/msg00712.html> thread) As discussed on the corresponding thread on gcc-patches@, I am about to commit a fix on mainline and on the 5.0 branch.