49 lines
1.7 KiB
Plaintext
49 lines
1.7 KiB
Plaintext
# asm-underscore.m4 serial 1
|
|
dnl Copyright (C) 2010 Free Software Foundation, Inc.
|
|
dnl This file is free software; the Free Software Foundation
|
|
dnl gives unlimited permission to copy and/or distribute it,
|
|
dnl with or without modifications, as long as this notice is preserved.
|
|
|
|
dnl From Bruno Haible. Based on as-underscore.m4 in GNU clisp.
|
|
|
|
# gl_ASM_SYMBOL_PREFIX
|
|
# Tests for the prefix of C symbols at the assembly language level and the
|
|
# linker level. This prefix is either an underscore or empty. Defines the
|
|
# C macro USER_LABEL_PREFIX to this prefix, and sets ASM_SYMBOL_PREFIX to
|
|
# a stringified variant of this prefix.
|
|
|
|
AC_DEFUN([gl_ASM_SYMBOL_PREFIX],
|
|
[
|
|
dnl We don't use GCC's __USER_LABEL_PREFIX__ here, because
|
|
dnl 1. It works only for GCC.
|
|
dnl 2. It is incorrectly defined on some platforms, in some GCC versions.
|
|
AC_CACHE_CHECK(
|
|
[whether C symbols are prefixed with underscore at the linker level],
|
|
[gl_cv_prog_as_underscore],
|
|
[cat > conftest.c <<EOF
|
|
#ifdef __cplusplus
|
|
extern "C" int foo (void);
|
|
#endif
|
|
int foo(void) { return 0; }
|
|
EOF
|
|
# Look for the assembly language name in the .s file.
|
|
AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS -S conftest.c) >/dev/null 2>&1
|
|
if grep _foo conftest.s >/dev/null ; then
|
|
gl_cv_prog_as_underscore=yes
|
|
else
|
|
gl_cv_prog_as_underscore=no
|
|
fi
|
|
rm -f conftest*
|
|
])
|
|
if test $gl_cv_prog_as_underscore = yes; then
|
|
USER_LABEL_PREFIX=_
|
|
else
|
|
USER_LABEL_PREFIX=
|
|
fi
|
|
AC_DEFINE_UNQUOTED([USER_LABEL_PREFIX], [$USER_LABEL_PREFIX],
|
|
[Define to the prefix of C symbols at the assembler and linker level,
|
|
either an underscore or empty.])
|
|
ASM_SYMBOL_PREFIX='"'${USER_LABEL_PREFIX}'"'
|
|
AC_SUBST([ASM_SYMBOL_PREFIX])
|
|
])
|