sh: Use stalloc for arith variable names.

This is simpler than the custom memory tracker I added earlier, and is also
needed by the dash arith code I plan to import.

3 files changed, 10 insertions, 24 deletions

diff --git a/bin/sh/arith.y b/bin/sh/arith.y
index 5db1633..28046ba 100644
--- a/bin/sh/arith.y
+++ b/bin/sh/arith.y
@@ -287,7 +287,9 @@ arith_t
 arith(const char *s)
 {
 	arith_t result;
+	struct stackmark smark;
 
+	setstackmark(&smark);
 	arith_buf = arith_startbuf = s;
 
 	INTOFF;
@@ -295,6 +297,8 @@ arith(const char *s)
 	arith_lex_reset();	/* Reprime lex. */
 	INTON;
 
+	popstackmark(&smark);
+
 	return result;
 }
 
diff --git a/bin/sh/arith_lex.l b/bin/sh/arith_lex.l
index f0d9cb3..aede40f 100644
--- a/bin/sh/arith_lex.l
+++ b/bin/sh/arith_lex.l
@@ -51,13 +51,6 @@ __FBSDID("$FreeBSD$");
 
 int yylex(void);
 
-struct varname
-{
-	struct varname *next;
-	char name[1];
-};
-static struct varname *varnames;
-
 #undef YY_INPUT
 #define YY_INPUT(buf,result,max) \
 	result = (*buf = *arith_buf++) ? 1 : YY_NULL;
@@ -87,14 +80,11 @@ static struct varname *varnames;
 			 * If variable doesn't exist, we should initialize
 			 * it to zero.
 			 */
-			struct varname *temp;
+			char *temp;
 			if (lookupvar(yytext) == NULL)
 				setvarsafe(yytext, "0", 0);
-			temp = ckmalloc(sizeof(struct varname) +
-			    strlen(yytext));
-			temp->next = varnames;
-			varnames = temp;
-			yylval.s_value = strcpy(temp->name, yytext);
+			temp = stalloc(strlen(yytext) + 1);
+			yylval.s_value = strcpy(temp, yytext);
 
 			return ARITH_VAR;
 		}
@@ -140,15 +130,5 @@ static struct varname *varnames;
 void
 arith_lex_reset(void)
 {
-	struct varname *name, *next;
-
 	YY_NEW_FILE;
-
-	name = varnames;
-	while (name != NULL) {
-		next = name->next;
-		ckfree(name);
-		name = next;
-	}
-	varnames = NULL;
 }
diff --git a/bin/sh/expand.c b/bin/sh/expand.c
index ab885ac..7d98737 100644
--- a/bin/sh/expand.c
+++ b/bin/sh/expand.c
@@ -360,7 +360,7 @@ removerecordregions(int endoff)
 void
 expari(int flag)
 {
-	char *p, *start;
+	char *p, *q, *start;
 	arith_t result;
 	int begoff;
 	int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
@@ -398,7 +398,9 @@ expari(int flag)
 	removerecordregions(begoff);
 	if (quotes)
 		rmescapes(p+2);
+	q = grabstackstr(expdest);
 	result = arith(p+2);
+	ungrabstackstr(q, expdest);
 	fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result);
 	while (*p++)
 		;