[Bug ada/109374] New: FAIL: gnat.dg/div_zero.adb execution test

[Bug ada/109374] New: FAIL: gnat.dg/div_zero.adb execution test

[danglin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

            Bug ID: 109374
           Summary: FAIL: gnat.dg/div_zero.adb execution test
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
          Assignee: unassigned at gcc dot gnu.org
          Reporter: danglin at gcc dot gnu.org
                CC: dkm at gcc dot gnu.org
  Target Milestone: ---
              Host: hppa*-*-linux*
            Target: hppa*-*-linux*
             Build: hppa*-*-linux*

Executing on host: /home/dave/gnu/gcc/objdir/gcc/gnatmake
--GCC=/home/dave/gnu/gcc/objdir/gcc/xgcc
--GNATBIND=/home/dave/gnu/gcc/objdir/gcc/gnatbind
--GNATLINK=/home/dave/gnu/gcc/objdir/gcc/gnatlink -cargs -B/ho
me/dave/gnu/gcc/objdir/gcc -largs --GCC=/home/dave/gnu/gcc/objdir/gcc/xgcc\
-B/home/dave/gnu/gcc/objdir/gcc\  -margs
--RTS=/home/dave/gnu/gcc/objdir/hppa-linux-gnu/./libada -q -f 
/home/dave/gnu/gcc/gcc/gcc/test
suite/gnat.dg/div_zero.adb  -largs  -margs  -fdiagnostics-plain-output   
-largs  -lm  -margs -o ./div_zero.exe    (timeout = 300)
spawn -ignore SIGHUP /home/dave/gnu/gcc/objdir/gcc/gnatmake
--GCC=/home/dave/gnu/gcc/objdir/gcc/xgcc
--GNATBIND=/home/dave/gnu/gcc/objdir/gcc/gnatbind
--GNATLINK=/home/dave/gnu/gcc/objdir/gcc/gnatlink -cargs -B/
home/dave/gnu/gcc/objdir/gcc -largs --GCC=/home/dave/gnu/gcc/objdir/gcc/xgcc
-B/home/dave/gnu/gcc/objdir/gcc  -margs
--RTS=/home/dave/gnu/gcc/objdir/hppa-linux-gnu/./libada -q -f
/home/dave/gnu/gcc/gcc/gcc/tests
uite/gnat.dg/div_zero.adb -largs -margs -fdiagnostics-plain-output -largs -lm
-margs -o ./div_zero.exe
Executing on host: /home/dave/gnu/gcc/objdir/gcc/gnatclean -c -q -n ./div_zero 
 (timeout = 300)
spawn -ignore SIGHUP /home/dave/gnu/gcc/objdir/gcc/gnatclean -c -q -n
./div_zero
./div_zero.ali
./div_zero.o
PASS: gnat.dg/div_zero.adb (test for excess errors)
Setting LD_LIBRARY_PATH to
:/home/dave/gnu/gcc/objdir/gcc::/home/dave/gnu/gcc/objdir/gcc:/home/dave/gnu/gcc/objdir/hppa-linux-gnu/libstdc++-v3/src/.libs:/home/dave/gnu/gcc/objdir/hppa-linux-gnu/libssp/.libs:/hom
e/dave/gnu/gcc/objdir/hppa-linux-gnu/libphobos/src/.libs:/home/dave/gnu/gcc/objdir/hppa-linux-gnu/libgm2/.libs:/home/dave/gnu/gcc/objdir/hppa-linux-gnu/libgomp/.libs:/home/dave/gnu/gcc/objdir/hppa-linux-gnu/liba
tomic/.libs:/home/dave/gnu/gcc/objdir/./gcc:/home/dave/gnu/gcc/objdir/./prev-gcc:/home/dave/gnu/gcc/objdir/hppa-linux-gnu/libstdc++-v3/src/.libs:/home/dave/gnu/gcc/objdir/hppa-linux-gnu/libssp/.libs:/home/dave/g
nu/gcc/objdir/hppa-linux-gnu/libphobos/src/.libs:/home/dave/gnu/gcc/objdir/hppa-linux-gnu/libgm2/.libs:/home/dave/gnu/gcc/objdir/hppa-linux-gnu/libgomp/.libs:/home/dave/gnu/gcc/objdir/hppa-linux-gnu/libatomic/.l
ibs:/home/dave/gnu/gcc/objdir/./gcc:/home/dave/gnu/gcc/objdir/./prev-gcc
Execution timeout is: 300
spawn [open ...]

raised CONSTRAINT_ERROR : SIGFPE
FAIL: gnat.dg/div_zero.adb execution test

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2023-04-02
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
                 CC|                            |ebotcazou at gcc dot gnu.org
          Component|ada                         |target

--- Comment #1 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
See the comment in the test.

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[dave.anglin at bell dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

--- Comment #2 from dave.anglin at bell dot net ---
I believe hppa-linux can unwind through signal frames.  VDSO support was added
fairly recently.
The unwind tests in glibc all pass.

GDB needs an update to unwind through signal frames with recent kernels.

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING

--- Comment #3 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> I believe hppa-linux can unwind through signal frames.  VDSO support was
> added fairly recently.

Does the unwinder compensate for the signal vs non-signal discrepancy?  See
__gnat_adjust_context_for_raise in ada/init.c:470 for possible tweaks.

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[dave.anglin at bell dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

--- Comment #4 from dave.anglin at bell dot net ---
On 2023-04-02 12:54 p.m., ebotcazou at gcc dot gnu.org wrote:
>> I believe hppa-linux can unwind through signal frames.  VDSO support was
>> added fairly recently.
> Does the unwinder compensate for the signal vs non-signal discrepancy?  See
> __gnat_adjust_context_for_raise in ada/init.c:470 for possible tweaks.
I don't think it does with VDSO kernels.  The unwinder uses
MD_FALLBACK_FRAME_STATE_FOR
with non VDSO kernels.

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[danglin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

--- Comment #5 from John David Anglin <danglin at gcc dot gnu.org> ---
I'm not sure what is expected here:

(gdb) r
Starting program: /home/dave/gnu/gcc/objdir/gcc/testsuite/gnat/div_zero.exe
warning: Unable to find libthread_db matching inferior's thread library, thread
debugging will not be available.

Program received signal SIGFPE, Arithmetic exception.
$$divoI () at ../../../gcc/libgcc/config/pa/milli64.S:448
448             addit,= 0,arg1,r0       /*  trap if divisor == 0 */
(gdb) c
Continuing.

Breakpoint 1, __gnat_error_handler (sig=8, si=0xf8f02488, ucontext=0xf8f02508)
at init.c:538
538          now, before we possibly trigger a recursive fault below.  */
(gdb) p/x ((ucontext_t *) ucontext)->uc_mcontext.sc_iaoq[0]
$2 = 0x1d1bf
(gdb) bt
#0  __gnat_error_handler (sig=8, si=0xf8f02488, ucontext=0xf8f02508) at
init.c:538
#1  <signal handler called>
#2  $$divoI () at ../../../gcc/libgcc/config/pa/milli64.S:448
#3  0x0001a124 in div_zero ()
(gdb) frame 2
#2  $$divoI () at ../../../gcc/libgcc/config/pa/milli64.S:448
448             addit,= 0,arg1,r0       /*  trap if divisor == 0 */
(gdb) disass $pc-16,$pc+16
Dump of assembler code from 0x1d1ac to 0x1d1cc:
   0x0001d1ac <$$divoI+428>:    bv,n r0(r31)
   0x0001d1b0 <$$divoI+432>:    nop
   0x0001d1b4 <$$divoI+436>:    blr,n r25,r0
   0x0001d1b8 <$$divoI+440>:    nop
=> 0x0001d1bc <$$divoI+444>:    addi,tc,= 0,r25,r0
   0x0001d1c0 <$$divoI+448>:    nop
   0x0001d1c4 <$$divoI+452>:    bv r0(r31)
   0x0001d1c8 <$$divoI+456>:    copy r26,ret1
End of assembler dump.
(gdb) frame 0
#0  __gnat_error_handler (sig=8, si=0xf8f02488, ucontext=0xf8f02508) at
init.c:538
538          now, before we possibly trigger a recursive fault below.  */
(gdb) ptype ((ucontext_t *) ucontext)->uc_mcontext.sc_iaoq[0]
type = unsigned long

As things stands, the pc (head iaoq value) points at the nop after the
addi,tc,= which caused the trap.

As far as I can tell, this test has always failed on both 32-bit linux and
hpux.

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

--- Comment #6 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> As far as I can tell, this test has always failed on both 32-bit linux and
> hpux.

Does libgcc/config/pa/milli64.S contain CFI directives or EH tables?

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[dave.anglin at bell dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

--- Comment #7 from dave.anglin at bell dot net ---
On 2023-04-03 4:46 p.m., ebotcazou at gcc dot gnu.org wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374
>
> --- Comment #6 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
>> As far as I can tell, this test has always failed on both 32-bit linux and
>> hpux.
> Does libgcc/config/pa/milli64.S contain CFI directives or EH tables?
No.

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

--- Comment #8 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> No.

Then the unwinder cannot unwind through it and the test cannot pass.

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by John David Anglin <danglin@gcc.gnu.org>:

https://gcc.gnu.org/g:ddb0f66e6c1e846bdc217075c9a770bfd0b01970

commit r13-7012-gddb0f66e6c1e846bdc217075c9a770bfd0b01970
Author: John David Anglin <danglin@gcc.gnu.org>
Date:   Wed Apr 5 14:44:54 2023 +0000

    Add assember CFI directives to millicode division and remainder routines.

    The millicode division and remainder routines trap division by zero.
    The unwinder needs these directives to unwind divide by zero traps.

    2023-04-05  John David Anglin  <danglin@gcc.gnu.org>

    libgcc/ChangeLog:

            PR target/109374
            * config/pa/milli64.S (RETURN_COLUMN): Define.
            ($$divI): Add CFI directives.
            ($$divU): Likewise.
            ($$remI): Likewise.
            ($$remU): Likewise.

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[danglin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

John David Anglin <danglin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|WAITING                     |RESOLVED

--- Comment #10 from John David Anglin <danglin at gcc dot gnu.org> ---
Fixed on trunk.

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

--- Comment #11 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
Nice work!

[Bug target/109374] FAIL: gnat.dg/div_zero.adb execution test

[dave.anglin at bell dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109374

--- Comment #12 from dave.anglin at bell dot net ---
On 2023-04-05 10:56 a.m., ebotcazou at gcc dot gnu.org wrote:
> Nice work!
Your comments were accurate and very helpful.

Thanks,
dave