[Bug sanitizer/79265] [7 regression] -fsanitize=undefined inserts unnecessary null pointer tests
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79265 --- Comment #6 from Franz Sirl --- (In reply to Jakub Jelinek from comment #4) > This is a new warning, the fact that we didn't warn on some code and now > warn with a new warning is not necessarily a regression. Well, I wasn't so sure either if it counts as a regression, that's why I asked on IRC first and then changed it. If you feel otherwise, you can remove the marker again. I guess it is kind of a "usability regression": - "gcc-6 -Wall -Werror": compiles - "gcc-6 -Wall -Werror -fsanitize=undefined": compiles - "gcc-7 -Wall -Werror": compiles - "gcc-7 -Wall -Werror -fsanitize=undefined": doesn't compile because of false warning So it's no longer enough to "just add -fsanitize=undefined" and recompile, now you have to adjust warnings as well. If it can't be reasonably solved within the GCC-7 timeframe, I would be fine with a stop-gap measure like removing -Wformat-overflow from -Wall when UBSAN is active (for example).
[Bug sanitizer/79265] [7 regression] -fsanitize=undefined inserts unnecessary null pointer tests
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79265 Jakub Jelinek changed: What|Removed |Added CC||law at gcc dot gnu.org --- Comment #5 from Jakub Jelinek --- What we could do is disable jump threading basic blocks that contain the cold sanitizer builtins, i.e. in between BEGIN_SANITIZER_BUILTINS and END_SANITIZER_BUILTINS if they have cold attribute (which is really undesirable in any case, such jump threading only grows the cold section unnecessarily). Or move the warning earlier such that it doesn't warn on code after threading, though that is likely not GCC7 material.
[Bug sanitizer/79265] [7 regression] -fsanitize=undefined inserts unnecessary null pointer tests
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79265 --- Comment #4 from Jakub Jelinek --- This is a new warning, the fact that we didn't warn on some code and now warn with a new warning is not necessarily a regression.
[Bug sanitizer/79265] [7 regression] -fsanitize=undefined inserts unnecessary null pointer tests
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79265 Franz Sirl changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2017-04-05 Summary|-fsanitize=undefined|[7 regression] |inserts unnecessary null|-fsanitize=undefined |pointer tests |inserts unnecessary null ||pointer tests Ever confirmed|0 |1 --- Comment #3 from Franz Sirl --- Code that used to compile warning-free with "gcc-6 -Wall -fsanitize=undefined" now throws a warning with current gcc-7.0.1.
