[PATCH 2/2] Eliminate incorrect check for grub_I386_CHECK_REGPARM_BUG

[Pavel Roskin]

NESTED_FUNC_ATTR is defined to "__attribute__ ((__regparm__ (1))" for
i386 targets regardless of the outcome of the test.  Since
NESTED_FUNC_ATTR is on the way out, a better test won't be written.

To be safe, define NESTED_FUNC_ATTR whenever we are compiling the
specific file for i386 architecture, even the target platform is not
i386 (i.e. compiling utilities when the host is i386 and the target is
not).

ChangeLog:

        * aclocal.m4 (grub_I386_CHECK_REGPARM_BUG): Remove.
        * configure.ac: Don't call grub_I386_CHECK_REGPARM_BUG.  Define
        NESTED_FUNC_ATTR by AH_BOTTOM.  Base NESTED_FUNC_ATTR value
        solely on the compile time architecture.
---
 aclocal.m4   |   54 ------------------------------------------------------
 configure.ac |    7 ++++++-
 2 files changed, 6 insertions(+), 55 deletions(-)

diff --git a/aclocal.m4 b/aclocal.m4
index 779df3d..38a9a4a 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -301,60 +301,6 @@ else
 fi
 ])
 
-dnl Check if the C compiler has a bug while using nested functions when
-dnl mregparm is used on the i386.  Some gcc versions do not pass the third
-dnl parameter correctly to the nested function.
-dnl Written by Marco Gerards.
-AC_DEFUN(grub_I386_CHECK_REGPARM_BUG,
-[AC_REQUIRE([AC_PROG_CC])
-AC_MSG_CHECKING([if GCC has the regparm=3 bug])
-AC_CACHE_VAL(grub_cv_i386_check_nested_functions,
-[AC_RUN_IFELSE([AC_LANG_SOURCE(
-[[
-static int
-test (int *n)
-{
-  return *n == -1;
-}
-
-static int
-testfunc (int __attribute__ ((__regparm__ (3))) (*hook) (int a, int b, int *c))
-{
-  int a = 0;
-  int b = 0;
-  int c = -1;
-  return hook (a, b, &c);
-}
-
-int
-main (void)
-{
-  int __attribute__ ((__regparm__ (3))) nestedfunc (int a, int b, int *c)
-    {
-      return a == b && test (c);
-    }
-  return testfunc (nestedfunc) ? 0 : 1;
-}
-]])],
-       [grub_cv_i386_check_nested_functions=no],
-       [grub_cv_i386_check_nested_functions=yes],
-       [grub_cv_i386_check_nested_functions=yes])])
-
-AC_MSG_RESULT([$grub_cv_i386_check_nested_functions])
-
-if test "x$grub_cv_i386_check_nested_functions" = xyes; then
-  AC_DEFINE([NESTED_FUNC_ATTR], 
-       [__attribute__ ((__regparm__ (1)))],
-       [Catch gcc bug])
-else
-dnl Unfortunately, the above test does not detect a bug in gcc-4.0.
-dnl So use regparm 2 until a better test is found.
-  AC_DEFINE([NESTED_FUNC_ATTR], 
-       [__attribute__ ((__regparm__ (1)))],
-       [Catch gcc bug])
-fi
-])
-
 dnl Check if the C compiler generates calls to `__enable_execute_stack()'.
 AC_DEFUN(grub_CHECK_ENABLE_EXECUTE_STACK,[
 AC_MSG_CHECKING([whether `$CC' generates calls to `__enable_execute_stack()'])
diff --git a/configure.ac b/configure.ac
index d84e2b6..0ba197e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -391,11 +391,16 @@ if test "x$target_cpu" = xi386; then
   grub_I386_ASM_PREFIX_REQUIREMENT
   grub_I386_ASM_ADDR32
   grub_I386_ASM_ABSOLUTE_WITHOUT_ASTERISK
-  grub_I386_CHECK_REGPARM_BUG
 else
   AC_DEFINE([NESTED_FUNC_ATTR], [], [Catch gcc bug])
 fi
 
+AH_BOTTOM([#ifdef __i386__
+#define NESTED_FUNC_ATTR __attribute__ ((__regparm__ (1)))
+#else
+#define NESTED_FUNC_ATTR
+#endif])
+
 # Restore the flags.
 CC="$tmp_CC"
 CFLAGS="$tmp_CFLAGS"