Enhance perly.fixer to help porters.

diff --git a/perly.fixer b/perly.fixer
index 98296a7..1568816 100755 (executable)
--- a/perly.fixer
+++ b/perly.fixer
@@ -5,8 +5,9 @@
 #  
 # However, if the user wishes to use byacc, or wishes to try another 
 # compiler compiler (e.g. bison or yacc), this script will get run.
+# See makefile run_byacc target for more details.
 #
-# Currently, only byacc version 1.8 is supported.
+# Currently, only byacc version 1.8 is fully supported.
 #
 #  Hacks to make it work with Interactive's SysVr3 Version 2.2
 #   doughera@lafvax.lafayette.edu (Andy Dougherty)   3/23/91
@@ -44,7 +45,15 @@ fi
 
 plan="unknown"
 
-# Below, we check for various yaccpar outputs.
+echo ""
+echo "Warning: the yacc you have used is not directly supported by perl."
+echo "The perly.fixer script will attempt to make some changes to the generated"
+echo "file. The changes may be incomplete and that might lead to problems later"
+echo "(especially with complex scripts). You may need to apply the changes"
+echo "embedded in perl.fixer (and/or perly.c.dif*) by hand."
+echo ""
+
+# Below, we check for various characteristic yaccpar outputs.
 
 #  Test for BSD 4.3 version.
 #  Also tests for the SunOS 4.0.2 version
@@ -73,13 +82,15 @@ if *\( *\+\+yy_ps *>= *&yys\[ *YYMAXDEPTH *\] *\)' $input >$tmp 2>/dev/null
     fi
 fi
 
+# ------
+
 case "$plan" in
     ##################################################################
     # The SunOS 4.0.2 version has the comparison fixed already.
     # Also added are out of memory checks (makes porting the generated
     # code easier) For most systems, it can't hurt. -- TD
     "bsd43")
-       echo "Patching perly.c to allow dynamic yacc stack allocation"
+       echo "Attempting to path perly.c to allow dynamic yacc stack allocation"
        echo "Assuming bsd4.3 yaccpar"
        cat >$tmp <<'END'
 /YYSTYPE[      ]*yyv\[ *YYMAXDEPTH *\];/c\
@@ -128,11 +139,15 @@ short *maxyyps;
 /yacc stack overflow.*}/d
 /yacc stack overflow/,/}/d
 END
-       sed -f $tmp <$input >$output ;;
+       if sed -f $tmp <$input >$output
+       then echo "The edit seems to have been applied okay."
+       else echo "The edit seems to have failed!"
+       fi
+       ;;
 
     #######################################################
     "isc") # Interactive Systems 2.2  version
-       echo "Patching perly.c to allow dynamic yacc stack allocation"
+       echo "Attempting to path perly.c to allow dynamic yacc stack allocation"
        echo "Assuming Interactive SysVr3 2.2 yaccpar"
        # Easier to simply put whole script here than to modify the
        # bsd script with sed.
@@ -178,11 +193,20 @@ int *maxyyps;
 \              }\
 \              if (yyv == NULL || yys == NULL)
 END
-       sed -f $tmp < $input > $output ;;
+       if sed -f $tmp < $input > $output
+       then echo "The edit seems to have been applied okay."
+       else echo "The edit seems to have failed!"
+       fi
+       ;;
 
     ######################################################
     # Plan still unknown
-    *) sed -e 's/Received token/ *** Received token/' $input >$output;
+    *)
+       echo "Unable to patch perly.c to allow dynamic yacc stack allocation (plan=$plan)"
+       # just do minimal change to write $output from $input
+       sed -e 's/Received token/ *** Received token/' $input >$output
+       ;;
 esac
 
+echo ""
 rm -rf $tmp $input