Debugging ICE in GCC

[Manfred Schwarb]

Bah, I hit the wrong button, answer went only to Dan.

Am 31.05.20 um 01:45 schrieb Manfred Schwarb:
> Am 30.05.20 um 04:01 schrieb Dan Kegel:
>> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95090 looks sorted, did you
>> figure out your gdb question?
>>
>
> Bug is sorted now, but debugging with printf's is a bit tedious ...
> So no, gdb question is not resolved. The issue is, I can't change frames
> or list code in GDB somehow.
>
>
>> On Fri, May 29, 2020, 16:55 Manfred Schwarb <manfred99@gmx.ch> wrote:
>>
>>> Hi,
>>> I tried to debug fortran.dg/pr95090.f90, which showed
>>>
>>> f951: internal compiler error: Segmentation fault
>>> 0x83cfe3c ???
>>>         ../sysdeps/i386/start.S:117
>>> Please submit a full bug report,
>>> with preprocessed source if appropriate.
>>> Please include the complete backtrace with any bug report.
>>> See <https://gcc.gnu.org/bugs/> for instructions.
>>>
>>>
>>> Using GDB (8.3.1), I got
>>> #> f951="`$instdir/bin/gcc -print-prog-name=f951`"
>>> #> gdb -ex run -ex bt --batch --args $f951 fortran.dg/pr95090.f90
>>>
>>> Program received signal SIGSEGV, Segmentation fault.
>>> 0xf7aa5162 in __strlen_sse2_bsf () from /lib/libc.so.6
>>> #0  0xf7aa5162 in __strlen_sse2_bsf () from /lib/libc.so.6
>>> #1  0x083e7c3f in get_unique_hashed_string(char*, gfc_symbol*) ()
>>> #2  0x083e85a4 in gfc_find_derived_vtab(gfc_symbol*) ()
>>> #3  0x0847fde1 in resolve_fl_derived(gfc_symbol*) ()
>>> #4  0x0847c717 in resolve_symbol(gfc_symbol*) ()
>>> #5  0x084a78d0 in do_traverse_symtree(gfc_symtree*, void
>>> (*)(gfc_symtree*), void (*)(gfc_symbol*)) ()
>>> #6  0x08487f77 in resolve_types(gfc_namespace*) ()
>>> #7  0x0847b6e5 in gfc_resolve(gfc_namespace*) ()
>>> #8  0x0846e9f6 in gfc_parse_file() ()
>>> #9  0x084bebe7 in gfc_be_parse_file() ()
>>> #10 0x08a3b59e in compile_file() ()
>>> #11 0x083c98a5 in toplev::main(int, char**) ()
>>> #12 0x083cd9b1 in main ()
>>>
>>>
>>> So far so good, but there are no file locations shown, and I can't
>>> switch frames and list code in GDB.
>>> This although I built GCC with debug information and binaries are not
>>> stripped.
>>>
>>> I built GCC with
>>> #> ../configure --enable-checking=yes,extra i686-linux
>>> #> make BOOT_CFLAGS="-O2 -ggdb" bootstrap2-lean
>>>
>>> In desperation, I even tried
>>> #> make BOOT_CFLAGS="-O2 -fanalyzer" bootstrap2-lean
>>> and
>>> #> make BOOT_CFLAGS="-O2 -fsanitize=address" bootstrap2-lean
>>> but both compilation attempts failed.
>>>
>>>
>>> Are there any magic knobs to make GDB output more useful?
>>>
>>> Thanks,
>>> Manfred
>>>
>>>
>>>
>>
>