Re: gawk --profile eats parentheses

[Aharon Robbins]

Greetings. Re this:

> Date: Tue, 11 Aug 2009 16:45:02 +0200
> From: Hermann Peifer <address@hidden>
> To: address@hidden
> Subject: gawk --profile eats parentheses
>
> $  gawk --profile '$1=="A" && ( $2=="B" || $3=="C" )'
>
> This results into:
>
> $ cat awkprof.out
>         # gawk profile, created Tue Aug 11 16:43:59 2009
>
>         # Rule(s)
>
>         $1 == "A" && $2 == "B" || $3 == "C"     {
>                 print $0
>         }
>
> In awkprof.out, the parentheses are lost which changes the logic of the 
> condition.
>
> (I am using gawk 3.1.6).
>
> Hermann

Indeed, it is a bug.  Thank you for reporting it.  The following
is against 3.1.7 (to which you should upgrade if at all possible :-).

Arnold
-------------------------------------------------------------
Tue Aug 11 19:23:51 2009  Arnold D. Robbins  <address@hidden>

        * profile.c (parenthesize_expr): New function.
        (tree_eval): Use it for Node_and and Node_or.

===================================================================
RCS file: /d/mongo/cvsrep/gawk-stable/profile.c,v
retrieving revision 1.12
diff -u -r1.12 profile.c
--- profile.c   21 Jul 2009 20:24:14 -0000      1.12
+++ profile.c   11 Aug 2009 16:25:13 -0000
@@ -34,6 +34,7 @@
 #undef tree_eval
 static void tree_eval P((NODE *tree));
 static void parenthesize P((NODETYPE parent_type, NODE *tree));
+static void parenthesize_expr P((NODETYPE parent_type, NODE *tree));
 static void eval_condition P((NODE *tree));
 static void pp_op_assign P((NODE *tree));
 static void pp_func_call P((NODE *tree));
@@ -465,15 +466,15 @@
                return;
 
        case Node_and:
-               eval_condition(tree->lnode);
+               parenthesize_expr(Node_and, tree->lnode);
                fprintf(prof_fp, " && ");
-               eval_condition(tree->rnode);
+               parenthesize_expr(Node_and, tree->rnode);
                return;
 
        case Node_or:
-               eval_condition(tree->lnode);
+               parenthesize_expr(Node_or, tree->lnode);
                fprintf(prof_fp, " || ");
-               eval_condition(tree->rnode);
+               parenthesize_expr(Node_or, tree->rnode);
                return;
 
        case Node_not:
@@ -1430,6 +1431,28 @@
        in_expr--;
 }
 
+/* parenthesize_expr --- print an expression subtree in parentheses if need be 
*/
+
+static void
+parenthesize_expr(NODETYPE parent_type, NODE *tree)
+{
+       NODETYPE child_type;
+
+       if (tree == NULL)
+               return;
+
+       child_type = tree->type;
+
+       in_expr++;
+       if (prec_level(child_type) < prec_level(parent_type)) {
+               fprintf(prof_fp, "(");
+               eval_condition(tree);
+               fprintf(prof_fp, ")");
+       } else
+               eval_condition(tree);
+       in_expr--;
+}
+
 /* pp_var --- print builtin variables, do it in one place */
 
 static void