Incorrect code caused a ICE: wws@w6ws-4:/tmp$ cat cls.f90 module cls_allocmod implicit none contains subroutine cls_alloc (n, str) integer, intent(in) :: n character(*), allocatable, intent(out) :: str ! Note: Star ^ should have been a colon (:) allocate (character(n)::str) end subroutine end module program cls use cls_allocmod implicit none character(:), allocatable :: string call cls_alloc (42, string) print *, 'string len =', len(string) end program wws@w6ws-4:/tmp$ Gfortran 5.4 produces an ICE. So do older versions (e.g., 4.8 on one of my other machines.): wws@w6ws-4:/tmp$ gfortran --version GNU Fortran (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609 Copyright (C) 2015 Free Software Foundation, Inc. GNU Fortran comes with NO WARRANTY, to the extent permitted by law. You may redistribute copies of GNU Fortran under the terms of the GNU General Public License. For more information about these matters, see the file named COPYING wws@w6ws-4:/tmp$ gfortran cls.f90 f951: internal compiler error: Segmentation fault Please submit a full bug report, with preprocessed source if appropriate. See <file:///usr/share/doc/gcc-5/README.Bugs> for instructions. wws@w6ws-4:/tmp$ The trunk as of a couple of days ago also produces an ICE - this time with a compiler traceback: wws@w6ws-4:/tmp$ /usr/local/gcc-trunk/bin/gfortran --version GNU Fortran (GCC) 8.0.0 20170927 (experimental) Copyright (C) 2017 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. wws@w6ws-4:/tmp$ /usr/local/gcc-trunk/bin/gfortran cls.f90 f951: internal compiler error: Segmentation fault 0xc906cf crash_signal ../../gcc-trunk/gcc/toplev.c:326 0x727af8 gfc_dep_compare_expr(gfc_expr*, gfc_expr*) ../../gcc-trunk/gcc/fortran/dependency.c:321 0x6fe687 resolve_allocate_expr ../../gcc-trunk/gcc/fortran/resolve.c:7391 0x6fe687 resolve_allocate_deallocate ../../gcc-trunk/gcc/fortran/resolve.c:7782 0x70067a gfc_resolve_code(gfc_code*, gfc_namespace*) ../../gcc-trunk/gcc/fortran/resolve.c:11212 0x701c02 resolve_codes ../../gcc-trunk/gcc/fortran/resolve.c:16236 0x701b07 resolve_codes ../../gcc-trunk/gcc/fortran/resolve.c:16221 0x701d06 gfc_resolve(gfc_namespace*) ../../gcc-trunk/gcc/fortran/resolve.c:16271 0x6eb54c gfc_parse_file() ../../gcc-trunk/gcc/fortran/parse.c:6217 0x7313af gfc_be_parse_file ../../gcc-trunk/gcc/fortran/f95-lang.c:204 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. wws@w6ws-4:/tmp$
PGI and NAG both catch this error. I can try Intel if needed.
ICE confirmed from 4.8 up to trunk. Compiling the test with my instrumented gfortran gives ../../work/gcc/fortran/dependency.c:321:11: runtime error: member access within null pointer of type 'struct gfc_expr' ASAN:DEADLYSIGNAL ================================================================= ==15952==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x0001003d484b bp 0x7fff5fbfe4b0 sp 0x7fff5fbfe490 T0) ==15952==The signal is caused by a READ memory access. ==15952==Hint: address points to the zero page. #0 0x1003d484a in gfc_dep_compare_expr(gfc_expr*, gfc_expr*) (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x1003d484a) #1 0x100337829 in resolve_allocate_expr(gfc_expr*, gfc_code*, bool*) (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x100337829) #2 0x10033f34d in resolve_allocate_deallocate(gfc_code*, char const*) (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x10033f34d) #3 0x1003535ee in gfc_resolve_code(gfc_code*, gfc_namespace*) (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x1003535ee) #4 0x100355d83 in resolve_codes(gfc_namespace*) (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x100355d83) #5 0x100355b2b in resolve_codes(gfc_namespace*) (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x100355b2b) #6 0x1002f42e1 in gfc_resolve(gfc_namespace*) (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x1002f42e1) #7 0x10029a2bf in gfc_parse_file() (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x10029a2bf) #8 0x1003f14f2 in gfc_be_parse_file() (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x1003f14f2) #9 0x1045a4bac in compile_file() (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x1045a4bac) #10 0x1045ad7fe in do_compile() (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x1045ad7fe) #11 0x10651f30d in toplev::main(int, char**) (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x10651f30d) #12 0x1065249ce in main (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x1065249ce) #13 0x7fffbcb65234 in start (/usr/lib/system/libdyld.dylib+0x5234) AddressSanitizer can not provide additional info. SUMMARY: AddressSanitizer: SEGV (/opt/gcc/gcc8g/libexec/gcc/x86_64-apple-darwin16.7.0/8.0.0/f951+0x1003d484a) in gfc_dep_compare_expr(gfc_expr*, gfc_expr*) 8820864) False positive error reports may follow For details see https://github.com/google/sanitizers/issues/189 f951: internal compiler error: Abort trap: 6
% svn diff resolve.c Index: resolve.c =================================================================== --- resolve.c (revision 253236) +++ resolve.c (working copy) @@ -7387,8 +7387,14 @@ resolve_allocate_expr (gfc_expr *e, gfc_code *code, bo if (code->ext.alloc.ts.type == BT_CHARACTER && !e->ts.deferred && !UNLIMITED_POLY (e)) { - int cmp = gfc_dep_compare_expr (e->ts.u.cl->length, - code->ext.alloc.ts.u.cl->length); + int cmp; + + if (!e->ts.u.cl->length) + goto failure; + + cmp = gfc_dep_compare_expr (e->ts.u.cl->length, + code->ext.alloc.ts.u.cl->length); + if (cmp == 1 || cmp == -1 || cmp == -3) { gfc_error ("Allocating %s at %L with type-spec requires the same "
(In reply to kargl from comment #3) > % svn diff resolve.c > Index: resolve.c > =================================================================== > --- resolve.c (revision 253236) > +++ resolve.c (working copy) > @@ -7387,8 +7387,14 @@ resolve_allocate_expr (gfc_expr *e, gfc_code *code, bo > if (code->ext.alloc.ts.type == BT_CHARACTER && !e->ts.deferred > && !UNLIMITED_POLY (e)) > { > - int cmp = gfc_dep_compare_expr (e->ts.u.cl->length, > - code->ext.alloc.ts.u.cl->length); > + int cmp; > + > + if (!e->ts.u.cl->length) > + goto failure; > + > + cmp = gfc_dep_compare_expr (e->ts.u.cl->length, > + code->ext.alloc.ts.u.cl->length); > + > if (cmp == 1 || cmp == -1 || cmp == -3) > { > gfc_error ("Allocating %s at %L with type-spec requires the same " Looks good (and obvious, too). Pre-approved.
Author: kargl Date: Wed Jan 10 23:26:15 2018 New Revision: 256464 URL: https://gcc.gnu.org/viewcvs?rev=256464&root=gcc&view=rev Log: 2018-01-10 Steven G. Kargl <kargl@gcc.gnu.org> PR fortran/82367 * resolve.c (resolve_allocate_expr): Check for NULL pointer. 2018-01-10 Steven G. Kargl <kargl@gcc.gnu.org> PR fortran/82367 * gfortran.dg/deferred_character_18.f90: New test. Added: trunk/gcc/testsuite/gfortran.dg/deferred_character_18.f90 Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/resolve.c trunk/gcc/testsuite/ChangeLog
Author: kargl Date: Wed Jan 10 23:41:48 2018 New Revision: 256466 URL: https://gcc.gnu.org/viewcvs?rev=256466&root=gcc&view=rev Log: 2018-01-10 Steven G. Kargl <kargl@gcc.gnu.org> PR fortran/82367 * resolve.c (resolve_allocate_expr): Check for NULL pointer. 2018-01-10 Steven G. Kargl <kargl@gcc.gnu.org> PR fortran/82367 * gfortran.dg/deferred_character_18.f90: New test. Added: branches/gcc-7-branch/gcc/testsuite/gfortran.dg/deferred_character_18.f90 Modified: branches/gcc-7-branch/gcc/fortran/ChangeLog branches/gcc-7-branch/gcc/fortran/resolve.c branches/gcc-7-branch/gcc/testsuite/ChangeLog
Author: kargl Date: Wed Jan 10 23:55:00 2018 New Revision: 256467 URL: https://gcc.gnu.org/viewcvs?rev=256467&root=gcc&view=rev Log: 2018-01-10 Steven G. Kargl <kargl@gcc.gnu.org> PR fortran/82367 * resolve.c (resolve_allocate_expr): Check for NULL pointer. 2018-01-10 Steven G. Kargl <kargl@gcc.gnu.org> PR fortran/82367 * gfortran.dg/deferred_character_18.f90: New test. Added: branches/gcc-6-branch/gcc/testsuite/gfortran.dg/deferred_character_18.f90 Modified: branches/gcc-6-branch/gcc/fortran/ChangeLog branches/gcc-6-branch/gcc/fortran/resolve.c branches/gcc-6-branch/gcc/testsuite/ChangeLog
Fixed on 6-branch, 7-branch, and trunk. Thanks for the bug report.