# AX_CPP_IDENT
# ------------
# Check if the C compiler supports #ident
# Define and substitute ident_support if so.
#
# It would be simpler and more consistent with the rest of the autoconf
# structure to AC_DEFINE(HAVE_CPP_IDENT) instead of
# ident_support='-DHAVE_CVS_IDENT=1' and AC_SUBST(ident_support), but that
# change would require all C files in the icarus top level directory to
# put #include <config.h> before the #ifdef HAVE_CVS_IDENT (and change
# HAVE_CVS_IDENT to HAVE_CPP_IDENT).   That would also remove all special
# ident_support handling from the Makefile.  Manyana.
#
AC_DEFUN([AX_CPP_IDENT],
[AC_CACHE_CHECK([for ident support in C compiler], ax_cv_cpp_ident,
[AC_TRY_COMPILE([
#ident "$Id: aclocal.m4,v 1.1 2003/11/08 19:27:50 steve Exp $"
],[while (0) {}],
[AS_VAR_SET(ax_cv_cpp_ident, yes)],
[AS_VAR_SET(ax_cv_cpp_ident, no)])])
if test $ax_cv_cpp_ident = yes; then
  ident_support='-DHAVE_CVS_IDENT=1'
fi
AC_SUBST(ident_support)
])# AC_CPP_IDENT


# _AX_C_UNDERSCORES_MATCH_IFELSE(PATTERN, ACTION-IF-MATCH, ACTION-IF-NOMATCH)
# ------------------------------
# Sub-macro for AX_C_UNDERSCORES_LEADING and AX_C_UNDERSCORES_TRAILING.
# Unwarranted assumptions:
#   - the object file produced by AC_COMPILE_IFELSE is called "conftest.$ac_objext"
#   - the nm(1) utility is available, and its name is "nm".
AC_DEFUN([_AX_C_UNDERSCORES_MATCH_IF],
[AC_COMPILE_IFELSE([void underscore(void){}],
[AS_IF([nm conftest.$ac_objext|grep $1 >/dev/null 2>/dev/null],[$2],[$3])],
[AC_MSG_ERROR([underscore test crashed])]
)])


# AX_C_UNDERSCORES_LEADING
# ---------------------------------
# Check if symbol names in object files produced by C compiler have
# leading underscores. Define NEED_LU if so.
AC_DEFUN([AX_C_UNDERSCORES_LEADING],
[AC_CACHE_CHECK([for leading underscores], ax_cv_c_underscores_leading,
[_AX_C_UNDERSCORES_MATCH_IF([_underscore],
[AS_VAR_SET(ax_cv_c_underscores_leading, yes)],
[AS_VAR_SET(ax_cv_c_underscores_leading, no)])])
if test $ax_cv_c_underscores_leading = yes; then
 AC_DEFINE(NEED_LU)
fi
])# AX_C_UNDERSCORES_LEADING


# AX_C_UNDERSCORES_TRAILING
# ---------------------------------
# Check if symbol names in object files produced by C compiler have
# trailing underscores.  Define NEED_TU if so.
AC_DEFUN([AX_C_UNDERSCORES_TRAILING],
[AC_CACHE_CHECK([for trailing underscores], ax_cv_c_underscores_trailing,
[_AX_C_UNDERSCORES_MATCH_IF([underscore_],
[AS_VAR_SET(ax_cv_c_underscores_trailing, yes)],
[AS_VAR_SET(ax_cv_c_underscores_trailing, no)])])
if test $ax_cv_c_underscores_trailing = yes; then
 AC_DEFINE(NEED_TU)
fi
])# AX_C_UNDERSCORES_TRAILING