[toplevel] Make configure.in more autoconfy

[Bonzini <bonzini at gnu dot org>]

I just wondered if there's a reason for these macro being expanded or
just (understandable) laziness.

Ok for mainline and src (please commit for me since I do not have access
to src)?

Paolo

2004-03-16  Paolo Bonzini  <bonzini@gnu.org>

	* configure.in (DEFAULT_YACC, DEFAULT_M4, DEFAULT_LEX):
	Set with AC_CHECK_PROGS.

Index: configure.in
===================================================================
RCS file: /cvs/gcc/gcc/configure.in,v
retrieving revision 1.276
diff -u -r1.276 configure.in
--- configure.in	16 Mar 2004 00:03:30 -0000	1.276
+++ configure.in	16 Mar 2004 09:34:25 -0000
@@ -1497,62 +1497,13 @@
 tooldir='${exec_prefix}'/${target_alias}
 build_tooldir=${tooldir}
 
-# Generate a default definition for YACC.  This is used if the makefile can't
-# locate bison or byacc in objdir.
+# Generate default definitions for YACC, M4, FLEX.  These are used if the
+# makefile can't locate these programs in objdir.
 
-for prog in 'bison -y' byacc yacc
-do
-  set dummy $prog; tmp=$2
-  IFS="${IFS= 	}"; save_ifs="$IFS"; IFS="${IFS}:"
-  for dir in $PATH; do
-    test -z "$dir" && dir=.
-    if test -f $dir/$tmp; then
-      DEFAULT_YACC="$prog"
-      break
-    fi
-  done
-  IFS="$save_ifs"
-
-  test -n "$DEFAULT_YACC" && break
-done
-
-# Generate a default definition for M4.  This is used if the makefile can't
-# locate m4 in objdir.
-
-for prog in gm4 gnum4 m4
-do
-  set dummy $prog; tmp=$2
-  IFS="${IFS=   }"; save_ifs="$IFS"; IFS="${IFS}:"
-  for dir in $PATH; do
-    test -z "$dir" && dir=.
-    if test -f $dir/$tmp; then
-      DEFAULT_M4="$prog"
-      break
-    fi
-  done
-  IFS="$save_ifs"
-
-  test -n "$DEFAULT_M4" && break
-done
-
-# Generate a default definition for LEX.  This is used if the makefile can't
-# locate flex in objdir.
-
-for prog in flex lex
-do
-  set dummy $prog; tmp=$2
-  IFS="${IFS= 	}"; save_ifs="$IFS"; IFS="${IFS}:"
-  for dir in $PATH; do
-    test -z "$dir" && dir=.
-    if test -f $dir/$tmp; then
-      DEFAULT_LEX="$prog"
-      break
-    fi
-  done
-  IFS="$save_ifs"
-
-  test -n "$DEFAULT_LEX" && break
-done
+$MISSING=`cd $ac_aux_dir && pwd`/missing
+AC_CHECK_PROGS([DEFAULT_YACC], ['bison -y' byacc yacc], [$MISSING bison])
+AC_CHECK_PROGS([DEFAULT_M4], [gm4 gnum4 m4], [$MISSING m4])
+AC_CHECK_PROGS([DEFAULT_LEX], [flex lex], [$MISSING flex])
 
 # FIXME Should this be done recursively ??? (Useful for e.g. gdbtest)
 # Set up the list of links to be made.