[PATCH] acinclude.m4: fix __builtin_alloca availability test

[Yann Droneaud]

Le jeudi 03 décembre 2009 à 21:48 +0100, Torbjorn Granlund a écrit :
> Yann Droneaud <yann at droneaud.fr> writes:
> 
>   # HG changeset patch
>   # User Yann Droneaud <yann at droneaud.fr>
>   # Date 1259853333 18000
>   # Node ID 3081e11883a3f2169a893e4f224d046f1f8ac93f
>   # Parent  5f710b3ff8457795a4e376281561c1aeeee1d3d4
>   acinclude.m4: fix __builtin_alloca availability test
>   
>   Use GMP_PROG_CC_WORKS_PART() instead of GMP_PROG_CC_WORKS_PART_TEST()
>   otherwise main() is not declared and the test program failed to link
>   
>   diff -r 5f710b3ff845 -r 3081e11883a3 acinclude.m4
>   --- a/acinclude.m4	Thu Dec 03 15:00:04 2009 +0100
>   +++ b/acinclude.m4	Thu Dec 03 10:15:33 2009 -0500
>   @@ -548,7 +548,7 @@
>    
>    # __builtin_alloca is not available everywhere, check it exists before
>    # seeing that it works
>   -GMP_PROG_CC_WORKS_PART_TEST([$1],[__builtin_alloca availability],
>   +GMP_PROG_CC_WORKS_PART([$1],[__builtin_alloca availability],
>    [int k; int foo () { __builtin_alloca (k); }],
>      [GMP_PROG_CC_WORKS_PART([$1], [alloca array],
>    [/* The following provokes an internal compiler error from Itanium HP-UX cc
> 
> This confuses me.
> 
> There is a main generated for this test, please see the generated
> configure.
> 

Seems not:

"
# __builtin_alloca is not available everywhere, check it exists before
# seeing that it works
if test "$gmp_prog_cc_works" = yes; then
  # remove anything that might look like compiler output to our "||"
expression
  rm -f conftest* a.out b.out a.exe a_out.exe
  cat >conftest.c <<EOF
int k; int foo () { __builtin_alloca (k); }
EOF
  echo "Test compile: __builtin_alloca availability" >&5
  gmp_compile="$cc $cflags $cppflags conftest.c >&5"
"

So it will always fail at link time.

Regards.

-- 
Yann Droneaud