[Bug ada/34289] New: Systematic recompilation of up-to-date object files when using the "-s" gnatmake option GNAT 4.3.0 on x86-*-Darwin8

["bechir dot zalila at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

Hi,

When recompiling an Ada file (attachements p.ads p.adb) using "-s" option for
gnatmake. The object file is systemtically rebuild even if it is up-to-date and
if even the compiler flags have not changed.

* How to reproduce the bug:
===========================

INPUT FILES:
============

Attached p.ads and p.adb

COMMAND LINE:
=============

Two successive executions of:

gnatmake -s p.adb

EXPECTED BEHAVIOR:
==================

first: gnatmake -s p.adb

gcc -c p.adb

second: gnatmake -s p.adb

<nothing> (object file is up to date, thus it is not recompiled)

ACTUAL BEHAVIOR:
================

first: gnatmake -s p.adb

gcc -c p.adb

second: gnatmake -s p.adb

gcc -c p.adb

Object file is recompiled systematically at each execution

MINI DIAGNOSTIC:
================

If we use the -v flag of gnatmake, we get the following output:

GNATMAKE  4.3.0 20071119 (experimental)
Copyright (C) 1995-2007, Free Software Foundation, Inc.
  "p.ali" being checked ...
  -> "p.adb" different number of switches
-mmacosx-version-min=10.4

gcc -c p.adb
End of compilation

The command line option '-mmacosx-version-min=10.4' is added automatically 
by gcc when calling gnat1.

Passing -v to gcc (gcc -v -c p.adb) gives the following (truncated) output:

Using built-in specs.
Target: i686-apple-darwin8
Configured with: ../gcc_trunk/configure --disable-nls
--prefix=/Volumes/Stock/dev/gcc-4.3_trunk --host=i686-apple-darwin8
--target=i686-apple-darwin8 --build=i686-apple-darwin8 --enable-languages=c,ada
--with-gmp=/opt/local
Thread model: posix
gcc version 4.3.0 20071119 (experimental) (GCC)

...

.../gnat1 -quiet -dumpbase p.adb -mmacosx-version-min=10.4 -mtune=generic -fPIC
p.adb -o /var/tmp//ccqsMDI3.s

...

There are indeed several options added by gcc to gnat1 (especially
-mmacosx-version-min=10.4 and -mtune=generic). But for some reason, only
-mmacosx-version-min=10.4 causes the problem.

Here is my system configuration:

* the exact version of GCC, as shown by "gcc -v";

Using built-in specs.
Target: i686-apple-darwin8
Configured with: ../gcc_trunk/configure --disable-nls
--prefix=/Volumes/Stock/dev/gcc-4.3_trunk --host=i686-apple-darwin8
--target=i686-apple-darwin8 --build=i686-apple-darwin8 --enable-languages=c,ada
--with-gmp=/opt/local
Thread model: posix
gcc version 4.3.0 20071119 (experimental) (GCC)

* the system type (uname -a);

Darwin xxxxxxxxx.xxxx.xx 8.11.1 Darwin Kernel Version 8.11.1: Wed Oct 10
18:23:28 PDT 2007; root:xnu-792.25.20~1/RELEASE_I386 i386 i386

* the options when GCC was configured/built;

../gcc_trunk/configure --disable-nls --prefix=/Volumes/Stock/dev/gcc-4.3_trunk
--host=i686-apple-darwin8 --target=i686-apple-darwin8
--build=i686-apple-darwin8 --enable-languages=c,ada --with-gmp=/opt/local


-- 
           Summary: Systematic recompilation of up-to-date object files when
                    using the "-s" gnatmake option GNAT 4.3.0 on x86-*-
                    Darwin8
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bechir dot zalila at gmail dot com
 GCC build triplet: i686-apple-darwin8
  GCC host triplet: i686-apple-darwin8
GCC target triplet: i686-apple-darwin8


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34289