+# FP_EVAL_STDERR(COMMAND)
+# -----------------------
+# Eval COMMAND, save its stderr (without lines resulting from shell tracing)
+# into the file conftest.err and the exit status in the variable fp_status.
+AC_DEFUN([FP_EVAL_STDERR],
+[{ (eval $1) 2>conftest.er1
+ fp_status=$?
+ grep -v '^ *+' conftest.er1 >conftest.err
+ rm -f conftest.er1
+ (exit $fp_status); }[]dnl
+])# FP_EVAL_STDERR
+
+
+# FP_CHECK_FLAG(FLAG, [ACTION-IF-SUPPORTED], [ACTION-IF-NOT-SUPPORTED])
+# ---------------------------------------------------------------------
+# Check to see whether the compiler for the current language supports a
+# particular option.
+#
+# Implementation note: When given an unkown option, GCC issues an warning on
+# stderr only, but returns an exit value of 0 nevertheless. Consequently we have
+# to check stderr *and* the exit value.
+#
+# Used by ghc.
+AC_DEFUN([FP_CHECK_FLAG],
+[AC_LANG_COMPILER_REQUIRE()dnl
+AC_LANG_CASE([C], [fp_compiler="$CC" m4_pushdef([fp_Flags], [CFLAGS])],
+ [C++], [fp_compiler="$CXX" m4_pushdef([fp_Flags], [CXXFLAGS])],
+ [Fortran 77], [fp_compiler="$F77" m4_pushdef([fp_Flags], [FFLAGS])])
+m4_pushdef([fp_Cache], [fp_cv_[]fp_Flags[]AS_TR_SH([$1])])[]dnl
+AC_CACHE_CHECK([whether $fp_compiler accepts $1], [fp_Cache],
+[AC_LANG_CONFTEST([AC_LANG_PROGRAM()])
+fp_save_flags="$fp_Flags"
+fp_Flags="$fp_Flags $1"
+fp_Cache=no
+if FP_EVAL_STDERR([$ac_compile conftest.$ac_ext]) >/dev/null; then
+ test -s conftest.err || fp_Cache=yes
+fi
+fp_Flags="$fp_save_flags"
+rm -f conftest.err conftest.$ac_ext])
+AS_IF([test $fp_Cache = yes], [$2], [$3])[]dnl
+m4_popdef([fp_Cache])[]dnl
+m4_popdef([fp_Flags])[]dnl
+])# FP_CHECK_FLAG
+
+
+# FP_PROG_CONTEXT_DIFF
+# --------------------
+# Figure out how to do context diffs. Sets the output variable ContextDiffCmd.
+#
+# Note: NeXTStep thinks diff'ing a file against itself is "trouble".
+#
+# Used by ghc, glafp-utils/ltx, and glafp-utils/runstdtest.
+AC_DEFUN([FP_PROG_CONTEXT_DIFF],
+[AC_CACHE_CHECK([for a working context diff], [fp_cv_context_diff],
+[echo foo > conftest1
+echo foo > conftest2
+fp_cv_context_diff=no
+for fp_var in '-C 1' '-c1'
+do
+ if diff $fp_var conftest1 conftest2 > /dev/null 2>&1; then
+ fp_cv_context_diff="diff $fp_var"
+ break
+ fi
+done])
+if test x"$fp_cv_context_diff" = xno; then
+ AC_MSG_ERROR([cannot figure out how to do context diffs])
+fi
+AC_SUBST(ContextDiffCmd, [$fp_cv_context_diff])
+])# FP_PROG_CONTEXT_DIFF
+
+
+# FP_COMPUTE_INT(EXPRESSION, VARIABLE, INCLUDES, IF-FAILS)
+# --------------------------------------------------------
+# Assign VARIABLE the value of the compile-time EXPRESSION using INCLUDES for
+# compilation. Execute IF-FAILS when unable to determine the value. Works for
+# cross-compilation, too.
+#
+# Implementation note: We are lazy and use an internal autoconf macro, but it
+# is supported in autoconf versions 2.50 up to the actual 2.57, so there is
+# little risk.
+AC_DEFUN([FP_COMPUTE_INT],
+[_AC_COMPUTE_INT([$1], [$2], [$3], [$4])[]dnl
+])# FP_COMPUTE_INT
+
+
+# FP_CHECK_ALIGNMENT(TYPE, [IGNORED], [INCLUDES = DEFAULT-INCLUDES])
+# ------------------------------------------------------------------
+# A variation of AC_CHECK_SIZEOF for computing the alignment restrictions of a
+# given type. Defines ALIGNMENT_TYPE.
+AC_DEFUN([FP_CHECK_ALIGNMENT],
+[AS_LITERAL_IF([$1], [],
+ [AC_FATAL([$0: requires literal arguments])])[]dnl
+AC_CHECK_TYPE([$1], [], [], [$3])[]dnl
+m4_pushdef([fp_Cache], [AS_TR_SH([fp_cv_alignment_$1])])[]dnl
+AC_CACHE_CHECK([alignment of $1], [fp_Cache],
+[if test "$AS_TR_SH([ac_cv_type_$1])" = yes; then
+ FP_COMPUTE_INT([(long) (&((struct { char c; $1 ty; } *)0)->ty)],
+ [fp_Cache],
+ [AC_INCLUDES_DEFAULT([$3])],
+ [AC_MSG_ERROR([cannot compute alignment ($1)
+See `config.log' for more details.], [77])])
+else
+ fp_Cache=0
+fi])[]dnl
+AC_DEFINE_UNQUOTED(AS_TR_CPP(alignment_$1), $fp_Cache, [The alignment of a `$1'.])[]dnl
+m4_popdef([fp_Cache])[]dnl
+])# FP_CHECK_ALIGNMENT
+
+
+# FP_LEADING_UNDERSCORE
+# ---------------------
+# Test for determining whether symbol names have a leading underscore. We assume
+# that they _haven't_ if anything goes wrong. Sets the output variable
+# LeadingUnderscore to YES or NO and defines LEADING_UNDERSCORE correspondingly.
+#
+# Some nlist implementations seem to try to be compatible by ignoring a leading
+# underscore sometimes (eg. FreeBSD). We therefore have to work around this by
+# checking for *no* leading underscore first. Sigh. --SDM
+#
+# Similarly on OpenBSD, but this test doesn't help. -- dons
+AC_DEFUN([FP_LEADING_UNDERSCORE],
+[AC_CHECK_LIB([elf], [nlist], [LIBS="-lelf $LIBS"])
+AC_CACHE_CHECK([leading underscore in symbol names], [fptools_cv_leading_underscore], [
+# Hack!: nlist() under Digital UNIX insist on there being an _,
+# but symbol table listings shows none. What is going on here?!?
+#
+# Another hack: cygwin doesn't come with nlist.h , so we hardwire
+# the underscoredness of that "platform"