Hi, Andrew - On Tue, Mar 09, 2021 at 10:05:04AM -0500, Andrew Cagney via Dwarf-Discuss wrote: > [...] > This means that: > - for simple objects, local functions; and > - with link-time-optimization, everything except library interface functions > are fair game for ABI non-compliant call optimizations. > > Is anyone aware of a compiler doing this (I figure with LTO there's a > strong incentive)? And if so, how is this described to the debugger. > The ABI / calling-convention is no longer on hand for filling in the > blanks.
FWIW, gcc does not leave ABI-dependent gaps in the DWARF generated for function parameters. First class location lists are given, whether or not they are in the ABI-governed locations, or whether they've been moved somewhere else, or whether they've been optimized out so that a consumer must recompute it somehow, or whether they exist at all. As I understand it, the location of *function return values* is however a gap in DWARF, and a consumer tool must resort to ABI specs. (Thus the elfutils dwfl_module_return_value_location() function.) I'm sure there's a Reason for this, but having worked on a consumer, it'd be handy if DWARF did explicitly identify the return value location too. - FChE _______________________________________________ Dwarf-Discuss mailing list Dwarf-Discuss@lists.dwarfstd.org http://lists.dwarfstd.org/listinfo.cgi/dwarf-discuss-dwarfstd.org
