Couple cleanups.

[bpt/guile.git] / libguile / guile-snarf.in

diff --git a/libguile/guile-snarf.in b/libguile/guile-snarf.in
index 41542dc..f6977ca 100644 (file)
--- a/libguile/guile-snarf.in
+++ b/libguile/guile-snarf.in
@@ -1,34 +1,93 @@
 #!/bin/sh
-# Extract the initialization actions for builtin things.
+# Extract the initialization actions from source files.
+#
+#  Copyright (C) 1996, 97, 98, 99, 2000, 2001, 2002, 2004 Free Software Foundation, Inc.
 #
-#  Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
-# 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation; either version 2, or (at your option)
 # any later version.
-# 
+#
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
-# 
+#
 # You should have received a copy of the GNU General Public License
 # along with this software; see the file COPYING.  If not, write to
 # the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 # Boston, MA 02111-1307 USA
 
-temp="/tmp/snarf.$$"
-trap "rm -f $temp" 0 1 2 15
+# Commentary:
+
+# Usage: guile-snarf [-o OUTFILE] [CPP-ARGS ...]
+ 
+# Initialization actions are extracted to OUTFILE or to standard
+# output when no OUTFILE has been specified or when OUTFILE is "-".
+# The C preprocessor is called with CPP-ARGS (which usually include a
+# input file) and the output is filtered for the actions.
+# 
+# If there are errors during processing, OUTFILE is deleted and the
+# program exits with non-zero status.
+# 
+# During snarfing, the pre-processor macro SCM_MAGIC_SNARFER is
+# defined.  You can use this to avoid including snarfer output files
+# that don't yet exist by writing code like this:
+# 
+#   #ifndef SCM_MAGIC_SNARFER
+#   #include "foo.x"
+#   #endif
+# 
+# If the environment variable CPP is set, use its value instead of the
+# C pre-processor determined at Guile configure-time: "@CPP@".
+
+# Code:
+
+## funcs
+
+modern_snarf ()                         # writes stdout
+{
+    ## Apparently, AIX's preprocessor is unhappy if you try to #include an
+    ## empty file.
+    echo "/* cpp arguments: $@ */" ;
+    ${cpp} -DSCM_MAGIC_SNARF_INITS -DSCM_MAGIC_SNARFER "$@" > ${temp} && cpp_ok_p=true
+    grep "^ *\^ *\^" ${temp} | sed -e "s/^ *\^ *\^//" -e "s/\^\ *:\ *\^.*/;/"
+}
+
+## main
+
+# process command line
+if [ x"$1" = x--help ] ; then
+    @AWK@ '/^#.Commentary:/,/^#.Code:/' $0 | grep -v Code: \
+        | sed -e 1,2d -e 's/^. *//g'
+    exit 0
+fi
+if [ x"$1" = x-o ]
+    then outfile="$2" ; shift ; shift ;
+    else  outfile="-" ;
+fi
+
+# set vars and handler -- handle CPP override
+cpp_ok_p=false
+tempdir="/tmp/snarf.$$"
+(umask 077 && mkdir $tempdir) || exit 1
+temp="$tempdir/tmp"
+if [ x"$CPP" = x ] ; then cpp="@CPP@" ; else cpp="$CPP" ; fi
+
+trap "rm -rf $tempdir" 0 1 2 15
 
-## Let the user override the preprocessor autoconf found.
-test -n "${CPP+set}" || CPP="@CPP@"
+if [ ! "$outfile" = "-" ] ; then
+    modern_snarf "$@" > $outfile
+else
+    modern_snarf "$@"
+fi
 
-## We must use a temporary file here, instead of a pipe, because we
-## need to know if CPP exits with a non-zero status.
-${CPP} -DSCM_MAGIC_SNARF_INITS "$@" > ${temp} || exit $?
-< ${temp} grep "^ *\^\^" | sed -e "s/^ *\^\^//"
+# zonk outfile if errors occurred
+if $cpp_ok_p ; then
+    exit 0
+else
+    [ ! "$outfile" = "-" ] && rm -f $outfile
+    exit 1
+fi
 
-## Apparently, AIX's preprocessor is unhappy if you try to #include an
-## empty file.
-echo
+# guile-snarf ends here