From: Peter Stephenson <pws@csr.com>
To: zsh-workers@sunsite.dk (Zsh hackers list)
Subject: Re: PATCH: 1.1: fix bug assigning to scalar in math
Date: Fri, 06 Jul 2001 19:27:10 +0100 [thread overview]
Message-ID: <Tc0a88d01549623670a@mailsweeper01.cambridgesiliconradio.com> (raw)
In-Reply-To: "Peter Stephenson"'s message of "Fri, 06 Jul 2001 19:08:50 BST." <Tc0a88d015496129c8d@mailsweeper01.cambridgesiliconradio.com>
Peter Stephenson wrote:
> It makes the math stack 100 words longer during each evaluation of an
> expression, so I was toying with turning the stack into a linked list
> instead of a fixed array of 100 structures. However, that is likely to
> have an adverse effect on execution time, whereas this ought to be
> relatively benign. So I haven't decided.
Brainwave. Use the type discriminator to flag that it's unset. This
replaces the previous version.
Index: Src/math.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/math.c,v
retrieving revision 1.9
diff -u -r1.9 math.c
--- Src/math.c 2001/04/20 06:13:36 1.9
+++ Src/math.c 2001/07/06 18:24:55
@@ -476,7 +476,7 @@
/**/
static void
-push(mnumber val, char *lval)
+push(mnumber val, char *lval, int getme)
{
if (sp == STACKSZ - 1)
zerr("stack overflow", NULL, 0);
@@ -484,8 +484,21 @@
sp++;
stack[sp].val = val;
stack[sp].lval = lval;
+ if (getme)
+ stack[sp].val.type = MN_UNSET;
}
+/**/
+static mnumber
+pop(int noget)
+{
+ struct mathvalue *mv = stack+sp;
+
+ if (mv->val.type == MN_UNSET && !noget)
+ mv->val = getnparam(mv->lval);
+ sp--;
+ return mv->val;
+}
/**/
static mnumber
@@ -615,8 +628,8 @@
if (tp & (OP_A2|OP_A2IR|OP_A2IO|OP_E2|OP_E2IO)) {
/* Make sure anyone seeing this message reports it. */
DPUTS(sp < 1, "BUG: math: not enough wallabies in outback.");
- b = stack[sp--].val;
- a = stack[sp--].val;
+ b = pop(0);
+ a = pop(what == EQ);
if (tp & (OP_A2IO|OP_E2IO)) {
/* coerce to integers */
@@ -785,13 +798,15 @@
}
if (tp & (OP_E2|OP_E2IO)) {
lv = stack[sp+1].lval;
- push(setvar(lv,c), lv);
+ push(setvar(lv,c), lv, 0);
} else
- push(c,NULL);
+ push(c,NULL, 0);
return;
}
spval = &stack[sp].val;
+ if (stack[sp].val.type == MN_UNSET)
+ *spval = getnparam(stack[sp].lval);
switch (what) {
case NOT:
if (spval->type & MN_FLOAT) {
@@ -837,11 +852,11 @@
break;
case QUEST:
DPUTS(sp < 2, "BUG: math: three shall be the number of the counting.");
- c = stack[sp--].val;
- b = stack[sp--].val;
- a = stack[sp--].val;
+ c = pop(0);
+ b = pop(0);
+ a = pop(0);
/* b and c can stay different types in this case. */
- push(((a.type & MN_FLOAT) ? a.u.d : a.u.l) ? b : c, NULL);
+ push(((a.type & MN_FLOAT) ? a.u.d : a.u.l) ? b : c, NULL, 0);
break;
case COLON:
zerr("':' without '?'", NULL, 0);
@@ -872,8 +887,12 @@
bop(int tk)
{
mnumber *spval = &stack[sp].val;
- int tst = (spval->type & MN_FLOAT) ? (zlong)spval->u.d : spval->u.l;
+ int tst;
+ if (stack[sp].val.type == MN_UNSET)
+ *spval = getnparam(stack[sp].lval);
+ tst = (spval->type & MN_FLOAT) ? (zlong)spval->u.d : spval->u.l;
+
switch (tk) {
case DAND:
case DANDEQ:
@@ -938,7 +957,15 @@
DPUTS(!errflag && sp,
"BUG: math: wallabies roaming too freely in outback");
- ret = stack[0].val;
+ if (errflag) {
+ ret.type = MN_INTEGER;
+ ret.u.l = errflag;
+ } else {
+ if (stack[0].val.type == MN_UNSET)
+ ret = getnparam(stack[0].lval);
+ else
+ ret = stack[0].val;
+ }
if (--mlevel) {
lastbase = xlastbase;
@@ -1056,16 +1083,16 @@
return;
switch (mtok) {
case NUM:
- push(yyval, NULL);
+ push(yyval, NULL, 0);
break;
case ID:
- push((noeval ? zero_mnumber : getnparam(yylval)), yylval);
+ push(zero_mnumber, yylval, !noeval);
break;
case CID:
- push((noeval ? zero_mnumber : getcvar(yylval)), yylval);
+ push((noeval ? zero_mnumber : getcvar(yylval)), yylval, 0);
break;
case FUNC:
- push((noeval ? zero_mnumber : callmathfunc(yylval)), yylval);
+ push((noeval ? zero_mnumber : callmathfunc(yylval)), yylval, 0);
break;
case M_INPAR:
mathparse(TOPPREC);
Index: Src/zsh.h
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/zsh.h,v
retrieving revision 1.32
diff -u -r1.32 zsh.h
--- Src/zsh.h 2001/06/27 11:22:05 1.32
+++ Src/zsh.h 2001/07/06 18:24:55
@@ -75,6 +75,7 @@
#define MN_INTEGER 1 /* mnumber is integer */
#define MN_FLOAT 2 /* mnumber is floating point */
+#define MN_UNSET 4 /* mnumber not yet retrieved */
typedef struct mathfunc *MathFunc;
typedef mnumber (*NumMathFunc)(char *, int, mnumber *, int);
Index: Test/C01arith.ztst
===================================================================
RCS file: /cvsroot/zsh/zsh/Test/C01arith.ztst,v
retrieving revision 1.1
diff -u -r1.1 C01arith.ztst
--- Test/C01arith.ztst 2001/04/02 12:32:11 1.1
+++ Test/C01arith.ztst 2001/07/06 18:24:55
@@ -88,3 +88,13 @@
print ${(t)newarray} ${#newarray} ${newarray[1]}
0:setting array elements in math context
>array 1 2
+
+ print $(( 13 = 42 ))
+1:bad lvalue
+?ZTST_execchunk:2: lvalue required
+
+ x=/bar
+ (( x = 32 ))
+ print $x
+0:assigning to scalar which contains non-math string
+>32
--
Peter Stephenson <pws@csr.com> Software Engineer
CSR Ltd., Unit 300, Science Park, Milton Road,
Cambridge, CB4 0XL, UK Tel: +44 (0)1223 392070
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prev parent reply other threads:[~2001-07-06 18:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-07-06 18:08 Peter Stephenson
2001-07-06 18:27 ` Peter Stephenson [this message]
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