glibc/sysdeps/arm/configure.ac

GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
# Local configure fragment for sysdeps/arm.

dnl It is always possible to access static and hidden symbols in an
dnl position independent way.
dnl NOTE: This feature was added by the GCC TLS patches.  We should test for
dnl it.  Until we do, don't define it.
#AC_DEFINE(PI_STATIC_AND_HIDDEN)

AC_CACHE_CHECK([whether the CFI directive .cfi_sections is supported],
  [libc_cv_asm_cfi_directive_sections],
  [cat > conftest.s <<EOF
	.text
	.cfi_sections .debug_frame, .eh_frame
	.cfi_startproc
	.cfi_endproc
EOF
  if AC_TRY_COMMAND(${CC-cc} $ASFLAGS -c conftest.s 1>&AS_MESSAGE_LOG_FD); then
    libc_cv_asm_cfi_directive_sections=yes
  else
    libc_cv_asm_cfi_directive_sections=no
  fi
  rm -f conftest*])
if test $libc_cv_asm_cfi_directive_sections != yes; then
  AC_MSG_ERROR([need .cfi_sections in this configuration])
fi

# We check to see if the compiler and flags are
# selecting the hard-float ABI and if they are then
# we set libc_cv_arm_pcs_vfp to yes which causes
# HAVE_ARM_PCS_VFP to be defined in config.h and
# in include/libc-symbols.h and thus available to
# shlib-versions to select the appropriate name for
# the dynamic linker via %ifdef.
AC_CACHE_CHECK([whether the compiler is using the ARM hard-float ABI],
  [libc_cv_arm_pcs_vfp],
  [AC_EGREP_CPP(yes,[#ifdef __ARM_PCS_VFP
                      yes
                     #endif
  ], libc_cv_arm_pcs_vfp=yes, libc_cv_arm_pcs_vfp=no)])
if test $libc_cv_arm_pcs_vfp = yes; then
  AC_DEFINE(HAVE_ARM_PCS_VFP)
  LIBC_CONFIG_VAR([default-abi], [hard])
else
  LIBC_CONFIG_VAR([default-abi], [soft])
fi