[Bug ada/68849] New: Bug box when using a type with static predicate as formal parameter of generic procedure

["lars.schulna at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68849

            Bug ID: 68849
           Summary: Bug box when using a type with static predicate as
                    formal parameter of generic procedure
           Product: gcc
           Version: 5.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
          Assignee: unassigned at gcc dot gnu.org
          Reporter: lars.schulna at gmail dot com
  Target Milestone: ---

Created attachment 36990
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36990&action=edit
Source file triggering the bug

Hello,

I ran into a gnat internal error while compiling the following file.

main.adb:

function Main return Integer
is

   type I is new Integer
   with Static_Predicate => True;
   --  with Dynamic_Predicate => True; -- 1

   generic
      type T is private;
   procedure P (X : T);
   procedure P (X : T) is null;
   --  procedure P; -- 2
   --  procedure P is null; -- 2

   procedure P_Inst is new P (I); -- 3

begin
   return 0;
end Main;

$ gcc -v -save-temps -gnatd.n -c main.adb
Using built-in specs.
COLLECT_GCC=gcc
Target: x86_64-unknown-linux-gnu
Configured with: /build/gcc/src/gcc-5.3.0/configure --prefix=/usr
--libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared
--enable-threads=posix --enable-libmpx --with-system-zlib --with-isl
--enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu
--disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object
--enable-linker-build-id --enable-lto --enable-plugin
--enable-install-libiberty --with-linker-hash-style=gnu
--enable-gnu-indirect-function --disable-multilib --disable-werror
--enable-checking=release
Thread model: posix
gcc version 5.3.0 (GCC) 
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-gnatd.n' '-c' '-mtune=generic'
'-march=x86-64'
 /usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/gnat1 -quiet -dumpbase main.adb
-auxbase main -gnatd.n -mtune=generic -march=x86-64 main.adb -o main.s
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/system.ads
main.adb
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/ada.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/a-textio.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/a-ioexce.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/a-stream.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/s-ficobl.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/interfac.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/i-cstrea.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/s-crtl.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/s-parame.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/s-wchcon.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/s-stalib.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/a-unccon.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/s-exctab.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/a-tags.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/s-stoele.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/s-soflin.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/a-except.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/s-traent.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/s-stache.ads
/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/adainclude/s-unstyp.ads
+===========================GNAT BUG DETECTED==============================+
| 5.3.0 (x86_64-unknown-linux-gnu) GCC error:                              |
| in gnat_to_gnu_entity, at ada/gcc-interface/decl.c:4445                  |
| Error detected at main.adb:12:4 [main.adb:18:4]                          |
| Please submit a bug report; see http://gcc.gnu.org/bugs.html.            |
| Use a subject line meaningful to you and us to track the bug.            |
| Include the entire contents of this bug box in the report.               |
| Include the exact command that you entered.                              |
| Also include sources listed below.                                       |
+==========================================================================+

Please include these source files with error report
Note that list may not be accurate in some cases,
so please double check that the problem can still
be reproduced with the set of files listed.
Consider also -gnatd.n switch (see debug.adb).

main.adb

compilation abandoned



To trigger this bug, the type I has to have a Static_Predicate or (as seen in
the comment marked with -- 1)
a Dynamic_Predicate.

However, this bug is *not* triggered when the type T is not used in P (as seen
in the comment marked with --2) or when it's never instantiated (line marked
with -- 3).

I was able to reproduce it with the adacore libre version
(gnat-gpl-2015-x86_64-linux-bin.tar.gz)
from http://libre.adacore.com/download/configurations on a x86_64 Linux
machine.

I used the latter configuration first and it told me to write to
report@adacore.com, which I did.
That was a week ago and there wasn't any reaction.
I'm sorry if this bug report is redundant.