[Bug ada/40185] New: Segmentation fault on legal program

[Bug ada/40185] New: Segmentation fault on legal program

[ludovic at ludovic-brenta dot org]

(Debian bug #519336)

The following illegal program causes gnat1 to crash with a segmentation fault:

with Ada.Unchecked_Conversion;
package Essai is
   type Attributed_Character is record
      I : Integer;
   end record;
   type Video_Array is array (Integer range 0 .. 1) of Attributed_Character;
   type Video_Access is access Video_Array;
   function To_VA is new Ada.Unchecked_Conversion (Integer, Video_Access);
   Video : Video_Access := To_VA (0); -- line 9
end Essai;

/usr/lib/gcc/x86_64-linux-gnu/4.3.3/gnat1 -quiet -dumpbase essai.ads
- -mtune=generic essai.ads -o  tutu.s
segmentation fault

Removing line 9 causes GNAT not to segfault.

Also confirmed on GNAT GPL 2008 on x86_64-linux-gnu and with GCC 4.3.3 on
powerpc-linux-gnu.


-- 
           Summary: Segmentation fault on legal program
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ludovic at ludovic-brenta dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40185

[Bug ada/40185] Segmentation fault on legal program

[ludovic at ludovic-brenta dot org]

------- Comment #1 from ludovic at ludovic-brenta dot org  2009-05-19 06:30 -------
There was a typo in the original program that I mistakenly corrected.  This
typo is the trigger for the bug:

with Ada.Unchecked_Conversion;
package Essai is
   type Attributed_Chararcter is record -- line 3
      I : Integer;
   end record;
   type Video_Array is array (Integer range 0 .. 1) of Attributed_Character;
   type Video_Access is access Video_Array;
   function To_VA is new Ada.Unchecked_Conversion (Integer, Video_Access);
   Video : Video_Access := To_VA (0); -- line 9
end Essai;

So, either correcting the typo at line 3 or removing line 9 prevents the
segmentation fault:

gnatmake essai.ads
gcc-4.3 -c essai.ads
gcc-4.3: Internal error: Segmentation fault (program gnat1)
Please submit a full bug report.
See <file:///usr/share/doc/gcc-4.3/README.Bugs> for instructions.
gnatmake: "essai.ads" compilation error

Now comment out line 9:
gnatmake essai.ads
gcc-4.3 -c essai.ads
essai.ads:6:56: "Attributed_Character" is undefined
essai.ads:6:56: possible misspelling of "Attributed_Chararcter"
gnatmake: "essai.ads" compilation error

Now restore line 9 and correct the typo at line 3:
gcc-4.3 -c essai.ads
essai.ads:8:04: warning: types for unchecked conversion have different sizes


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40185