Am 30.05.20 um 09:39 schrieb Jonathan Wakely: > On Sat, 30 May 2020 at 02:01, Manfred Schwarb <manfred99@xxxxxx> 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? > > There's a whole wiki page about that: > https://gcc.gnu.org/wiki/DebuggingGCC > Thanks a lot for the pointer. I didn't know about "--enable-valgrind-annotations" and "setarch -R". But this does not help me getting gdb working. As mentioned, gdb does not let me change frames or list code, unfortunately. BOOT_CFLAGS="-O2 -fsanitize=address" would be really handy, it seems to me... > You probably don't want to use -O2 >
