[Bug ada/110314] Gnat failed assertion and Allocators with discriminant

["franckbehaghel_gcc at protonmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110314

--- Comment #2 from Franck Behaghel <franckbehaghel_gcc at protonmail dot com> ---

>This is new in 14, was OK when forking 13.
>https://ada.godbolt.org/z/TvbPxYfnP
>Currently bisecting.

Marc,
Released version may have checks disabled :
If the file gcc/DEV-PHASE contains experimental, the configure script set
--enable-checking=yes
When releasing, gcc/DEV-PHASE is not experimental anymore.
Hence, gcc 13.1 may seem not affected in Compiler Explorer.


The stack trace :

gcc -wrapper gdb,--args -c main_assertion_failed.adb

(gdb) catch exception
Catchpoint 1: all Ada exceptions


Catchpoint 1, ADA.ASSERTIONS.ASSERTION_ERROR (nlists.adb:172) at
<__gnat_debug_raise_exception> (e=0x2b80988 <ada.assertions.assertion_error>,
message=...) at /opt/gcc/gcc/ada/libgnat/s-excdeb.adb:38
38      /opt/gcc/gcc/ada/libgnat/s-excdeb.adb: No such file or directory.
(gdb) bt
#0  <__gnat_debug_raise_exception> (e=0x2b80988
<ada.assertions.assertion_error>, message=...) at
/opt/gcc/gcc/ada/libgnat/s-excdeb.adb:38
#1  0x0000000000cd3a2c in ada.exceptions.complete_occurrence
(x=x@entry=0x33089e0) at /opt/gcc/gcc/ada/libgnat/a-except.adb:1013
#2  0x0000000000cd495c in ada.exceptions.complete_and_propagate_occurrence
(x=x@entry=0x33089e0) at /opt/gcc/gcc/ada/libgnat/a-except.adb:1024
#3  0x0000000000cd49a4 in <__gnat_raise_exception> (e=0x2b80988
<ada.assertions.assertion_error>, message=...) at
/opt/gcc/gcc/ada/libgnat/a-except.adb:1061
#4  0x0000000000cd700c in system.assertions.raise_assert_failure (msg=...) at
/opt/gcc/gcc/ada/libgnat/s-assert.adb:44
#5  0x0000000000a90840 in nlists.append (node=19969, to=to@entry=-99989077) at
/opt/gcc/gcc/ada/nlists.adb:172
#6  0x0000000000b7ee34 in sem_ch4.analyze_allocator (n=853) at
/opt/gcc/gcc/ada/sem_ch4.adb:615
#7  0x0000000000ae6d80 in sem.analyze (n=n@entry=853) at
/opt/gcc/gcc/ada/sem.adb:149
#8  0x0000000000b728e4 in sem_ch3.analyze_object_declaration (n=n@entry=852) at
/opt/gcc/gcc/ada/sem_ch3.adb:4445
#9  0x0000000000ae6d5c in sem.analyze (n=n@entry=852) at
/opt/gcc/gcc/ada/sem.adb:359
#10 0x0000000000b591d0 in sem_ch3.analyze_declarations (l=-99999982) at
/opt/gcc/gcc/ada/sem_ch3.adb:2707
#11 0x0000000000ba3c48 in sem_ch6.analyze_subprogram_body_helper (n=0) at
/opt/gcc/gcc/ada/sem_ch6.adb:4631
#12 sem_ch6.analyze_subprogram_body (n=n@entry=814) at
/opt/gcc/gcc/ada/sem_ch6.adb:2245
#13 0x0000000000ae6ed4 in sem.analyze (n=n@entry=814) at
/opt/gcc/gcc/ada/sem.adb:564
#14 0x0000000000b10628 in sem_ch10.analyze_compilation_unit (n=n@entry=798) at
/opt/gcc/gcc/ada/sem_ch10.adb:930
#15 0x0000000000ae6a28 in sem.analyze (n=n@entry=798) at
/opt/gcc/gcc/ada/sem.adb:185
#16 0x0000000000ae7f44 in sem.semantics.do_analyze () at
/opt/gcc/gcc/ada/sem.adb:1476
#17 sem.semantics (comp_unit=798) at /opt/gcc/gcc/ada/sem.adb:1672
#18 0x0000000000a6636c in frontend () at /opt/gcc/gcc/ada/frontend.adb:425
#19 0x0000000000ce2420 in gnat1drv () at /opt/gcc/gcc/ada/gnat1drv.adb:1236
#20 0x0000000000883c00 in gnat_parse_file () at
/opt/gcc/gcc/ada/gcc-interface/misc.cc:118
#21 0x000000000128ba10 in compile_file () at /opt/gcc/gcc/toplev.cc:444
#22 0x00000000008594c4 in do_compile (no_backend=false) at
/opt/gcc/gcc/toplev.cc:2126



It seems to failed because gnat add the same "discriminant node" into 2
differents "nlists" which do not supports its.