view Lib/fftw-3.2.1/m4/ax_gcc_aligns_stack.m4 @ 1:e86e9c111b29

Updates stuff that potentially fixes the memory leak and also makes it work on Windows and Linux (Need to test). Still have to fix fftw include for linux in Jucer.

dnl @synopsis AX_GCC_ALIGNS_STACK([ACTION-IF-YES], [ACTION-IF-NO])
dnl @summary check whether gcc can align stack to 8-byte boundary
dnl @category Misc
dnl
dnl Check to see if we are using a version of gcc that aligns the stack
dnl (true in gcc-2.95+, which have the -mpreferred-stack-boundary flag).
dnl Also, however, checks whether main() is correctly aligned by the
dnl OS/libc/..., as well as for a bug in the stack alignment of gcc-2.95.x
dnl (see http://gcc.gnu.org/ml/gcc-bugs/1999-11/msg00259.html).
dnl
dnl ACTION-IF-YES/ACTION-IF-NO are shell commands to execute if we are
dnl using gcc and the stack is/isn't aligned, respectively.
dnl
dnl Requires macro: AX_CHECK_COMPILER_FLAGS, AX_GCC_VERSION
dnl
dnl @version 2005-05-30
dnl @license GPLWithACException
dnl @author Steven G. Johnson <[e-mail]>
AC_DEFUN([AX_GCC_ALIGNS_STACK],
[
AC_REQUIRE([AC_PROG_CC])
ax_gcc_aligns_stack=no
if test "$GCC" = "yes"; then
AX_CHECK_COMPILER_FLAGS(-mpreferred-stack-boundary=4, [
	AC_MSG_CHECKING([whether the stack is at least 8-byte aligned by gcc])
	save_CFLAGS="$CFLAGS"
	CFLAGS="-O"
	AX_CHECK_COMPILER_FLAGS(-malign-double, CFLAGS="$CFLAGS -malign-double")
	AC_TRY_RUN([#include <stdlib.h>
#       include <stdio.h>
	struct yuck { int blechh; };
	int one(void) { return 1; }
	struct yuck ick(void) { struct yuck y; y.blechh = 3; return y; }
#       define CHK_ALIGN(x) if ((((long) &(x)) & 0x7)) { fprintf(stderr, "bad alignment of " #x "\n"); exit(1); }
	void blah(int foo) { double foobar; CHK_ALIGN(foobar); }
	int main2(void) {double ok1; struct yuck y; double ok2; CHK_ALIGN(ok1);
                         CHK_ALIGN(ok2); y = ick(); blah(one()); return 0;}
	int main(void) { if ((((long) (__builtin_alloca(0))) & 0x7)) __builtin_alloca(4); return main2(); }
	], [ax_gcc_aligns_stack=yes; ax_gcc_stack_align_bug=no], 
	ax_gcc_stack_align_bug=yes, [AX_GCC_VERSION(3,0,0, ax_gcc_stack_align_bug=no, ax_gcc_stack_align_bug=yes)])
	CFLAGS="$save_CFLAGS"
	AC_MSG_RESULT($ax_gcc_aligns_stack)
])
fi
if test "$ax_gcc_aligns_stack" = yes; then
	m4_default([$1], :)
else
	m4_default([$2], :)
fi
])