Re: Bug in regexp operator when warn_create_global is in effect

[Peter Stephenson <p.stephenson@xxxxxxxxxxx>]

On Thu, 02 Feb 2017 08:37:16 +0100
Ronald Fischer <ynnor@xxxxx> wrote:
> Consider the following program:
> 
>    #!/bin/zsh
>    function f {
>       [[ x =~ x ]]
>    }
>    setopt warn_create_global
>    f
> 
> When run by zsh 5.2 (x86_64-ubuntu-linux-gnu), I get the error messages:
> 
> f:1: scalar parameter MATCH created globally in function f
> f:1: numeric parameter MBEGIN created globally in function f
> f:1: numeric parameter MEND created globally in function f
> 
> While it is correct, that regexp matching sets, as side effect, the
> variables mentioned here, it doesn't, IMHO, make much sense that a zsh
> user, who not even *uses* these variables, receives these error
> messages.

Yes, you're right, the user doesn't even necessarily want them, which is
different from the case of the globbing flags in native zsh
expressions.  So probably best to turn the warnings off.

We don't yet have quite the full infrastructure for numerical
variables, annoyingly, but probably useful to add anyway...

pws

diff --git a/Src/Modules/regex.c b/Src/Modules/regex.c
index edb7234..d02769e 100644
--- a/Src/Modules/regex.c
+++ b/Src/Modules/regex.c
@@ -111,7 +111,7 @@ zcond_regex_match(char **a, int id)
 		*x = NULL;
 	    }
 	    if (isset(BASHREMATCH)) {
-		setaparam("BASH_REMATCH", arr);
+		assignaparam("BASH_REMATCH", arr, 0);
 	    } else {
 		zlong offs;
 		char *ptr;
@@ -119,7 +119,7 @@ zcond_regex_match(char **a, int id)
 
 		m = matches;
 		s = metafy(lhstr + m->rm_so, m->rm_eo - m->rm_so, META_DUP);
-		setsparam("MATCH", s);
+		assignsparam("MATCH", s, 0);
 		/*
 		 * Count the characters before the match.
 		 */
@@ -133,7 +133,7 @@ zcond_regex_match(char **a, int id)
 		    ptr += clen;
 		    leftlen -= clen;
 		}
-		setiparam("MBEGIN", offs + !isset(KSHARRAYS));
+		assigniparam("MBEGIN", offs + !isset(KSHARRAYS), 0);
 		/*
 		 * Add on the characters in the match.
 		 */
@@ -144,7 +144,7 @@ zcond_regex_match(char **a, int id)
 		    ptr += clen;
 		    leftlen -= clen;
 		}
-		setiparam("MEND", offs + !isset(KSHARRAYS) - 1);
+		assigniparam("MEND", offs + !isset(KSHARRAYS) - 1, 0);
 		if (nelem) {
 		    char **mbegin, **mend, **bptr, **eptr;
 		    bptr = mbegin = (char **)zalloc(sizeof(char *)*(nelem+1));
diff --git a/Src/params.c b/Src/params.c
index 20abe6a..19cbb1c 100644
--- a/Src/params.c
+++ b/Src/params.c
@@ -3192,11 +3192,12 @@ sethparam(char *s, char **val)
 
 /*
  * Set a generic shell number, floating point or integer.
+ * Option to warn on setting.
  */
 
 /**/
-Param
-setnparam(char *s, mnumber val)
+mod_export Param
+assignnparam(char *s, mnumber val, int flags)
 {
     struct value vbuf;
     Value v;
@@ -3248,15 +3249,41 @@ setnparam(char *s, mnumber val)
 	    unqueue_signals();
 	    return NULL;
 	}
-	check_warn_pm(v->pm, "numeric", !was_unset, 1);
+	if (flags & ASSPM_WARN)
+	    check_warn_pm(v->pm, "numeric", !was_unset, 1);
     } else {
-	check_warn_pm(v->pm, "numeric", 0, 1);
+	if (flags & ASSPM_WARN)
+	    check_warn_pm(v->pm, "numeric", 0, 1);
     }
     setnumvalue(v, val);
     unqueue_signals();
     return v->pm;
 }
 
+/*
+ * Set a generic shell number, floating point or integer.
+ * Warn on setting based on option.
+ */
+
+/**/
+mod_export Param
+setnparam(char *s, mnumber val)
+{
+    return assignnparam(s, val, ASSPM_WARN);
+}
+
+/* Simplified interface to assignnparam */
+
+/**/
+mod_export Param
+assigniparam(char *s, zlong val, int flags)
+{
+    mnumber mnval;
+    mnval.type = MN_INTEGER;
+    mnval.u.l = val;
+    return assignnparam(s, mnval, flags);
+}
+
 /* Simplified interface to setnparam */
 
 /**/
@@ -3266,7 +3293,7 @@ setiparam(char *s, zlong val)
     mnumber mnval;
     mnval.type = MN_INTEGER;
     mnval.u.l = val;
-    return setnparam(s, mnval);
+    return assignnparam(s, mnval, ASSPM_WARN);
 }
 
 /*