[Bug debug/51358] incorrect/missing location for function arg, -O0, without VTA
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51358 --- Comment #13 from Ben Woodard --- This adds some additional complexity to a feature request in https://sourceware.org/bugzilla/show_bug.cgi?id=19949. It would be helpful it were resolved.
[Bug debug/51358] incorrect/missing location for function arg, -O0, without VTA
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51358 --- Comment #12 from Mark Wielaard --- Having to parse line information to skip the prologue us somewhat inconvenient. Especially since GCC doesn't actually emit DW_LNS_set_prologue_end, you have to use some heuristic to determine whether you have reach the end of the prologue. As an alternative it might be nice if GCC could emit a DW_AT_GNU_entry_breakpoint that indicates where the "valid scope" of the function starts (it could either be an address or a constant to be added to low_pc).
[Bug debug/51358] incorrect/missing location for function arg, -O0, without VTA
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51358 --- Comment #11 from Frank Ch. Eigler fche at redhat dot com --- This problem continues to hit in gcc 4.8.2.
[Bug debug/51358] incorrect/missing location for function arg, -O0, without VTA
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51358 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Target Milestone|4.8.0 |--- Summary|[4.8 Regression]|incorrect/missing location |incorrect/missing location |for function arg, -O0, |for function arg, -O0, |without VTA |without VTA | --- Comment #10 from Richard Biener rguenth at gcc dot gnu.org 2012-12-06 16:21:33 UTC --- Don't see that either.
[Bug debug/51358] incorrect/missing location for function arg, -O0, without VTA
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51358 --- Comment #7 from Richard Guenther rguenth at gcc dot gnu.org 2012-08-13 08:55:05 UTC --- (In reply to comment #4) It would not be helpful, systemtap would then see no data (just not wrong data). Also at that time location list will need to be used and currently GDB when it sees any location list it thinks it no longer needs to skip the prologue. OTOH GDB could look at -grecord-gcc-switches first which it currently does not so I should just finally implement -grecord-gcc-switches in GDB in such case. I think seeing wrong data, thus, wrong-debug is never superior over no debug info / no data.
[Bug debug/51358] incorrect/missing location for function arg, -O0, without VTA
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51358 --- Comment #4 from Jan Kratochvil jan.kratochvil at redhat dot com 2012-08-12 18:37:26 UTC --- It would not be helpful, systemtap would then see no data (just not wrong data). Also at that time location list will need to be used and currently GDB when it sees any location list it thinks it no longer needs to skip the prologue. OTOH GDB could look at -grecord-gcc-switches first which it currently does not so I should just finally implement -grecord-gcc-switches in GDB in such case.
[Bug debug/51358] incorrect/missing location for function arg, -O0, without VTA
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51358 --- Comment #5 from Frank Ch. Eigler fche at redhat dot com 2012-08-12 20:21:24 UTC --- (In reply to comment #4) It would not be helpful, systemtap would then see no data [...] Not quite; systemtap can search the PC ranges/line tables for a nearby address where a corrected location list would cover.
[Bug debug/51358] incorrect/missing location for function arg, -O0, without VTA
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51358 --- Comment #6 from Mark Wielaard mark at gcc dot gnu.org 2012-08-12 20:30:36 UTC --- (In reply to comment #5) (In reply to comment #4) It would not be helpful, systemtap would then see no data [...] Not quite; systemtap can search the PC ranges/line tables for a nearby address where a corrected location list would cover. And at least systemtap could give an error/warning to the user the data isn't available instead of providing bogus values...
[Bug debug/51358] incorrect/missing location for function arg, -O0, without VTA
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51358 Richard Guenther rguenth at gcc dot gnu.org changed: What|Removed |Added Keywords||wrong-debug Status|UNCONFIRMED |NEW Last reconfirmed||2012-08-06 CC||rguenth at gcc dot gnu.org Ever Confirmed|0 |1 --- Comment #3 from Richard Guenther rguenth at gcc dot gnu.org 2012-08-06 18:35:35 UTC --- I also recently ran into this ... why can't GCC simply provide no location information for the prologue? Thus, properly restrict the PC range the fb-based locations are valid? At the moment GCC simply lies. Confirmed.
