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change semantics of non-strict compare operator for buffers and pointers

pull/1/head
Sami Vaarala 11 years ago
parent
b0c4f2fc4a
commit
43e407aa2d
1 changed files with 53 additions and 37 deletions
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  1. 90
      src/duk_js_ops.c

90
src/duk_js_ops.c
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@ -430,9 +430,10 @@ int duk_js_equals_number(double x, double y) {
return 0;
}
/* E5 Section 11.9.3 */
/* E5 Section 11.9.3. */
int duk_js_equals(duk_hthread *thr, duk_tval *tv_x, duk_tval *tv_y) {
duk_context *ctx = (duk_context *) thr;
duk_tval *tv_tmp;
/*
* FIXME: very direct translation now - should be made more
@ -442,8 +443,8 @@ int duk_js_equals(duk_hthread *thr, duk_tval *tv_x, duk_tval *tv_y) {
/*
* Same type?
*
* Note: since number values have no explicit tag, need the awkward
* if + switch.
* Note: since number values have no explicit tag in the 8-byte
* representation, need the awkward if + switch.
*/
if (DUK_TVAL_IS_NUMBER(tv_x) && DUK_TVAL_IS_NUMBER(tv_y)) {
@ -500,6 +501,9 @@ int duk_js_equals(duk_hthread *thr, duk_tval *tv_x, duk_tval *tv_y) {
/*
* Types are different; various cases
*
* Since comparison is symmetric, we use a "swap trick" to reduce
* code size.
*/
/* undefined/null are considered equal (e.g. "null == undefined" -> true) */
@ -508,38 +512,57 @@ int duk_js_equals(duk_hthread *thr, duk_tval *tv_x, duk_tval *tv_y) {
return 1;
}
/* number/string -> coerce string to number (e.g. "'1.5' == 1.5" -> true) */
if (DUK_TVAL_IS_NUMBER(tv_x) && DUK_TVAL_IS_STRING(tv_y)) {
/* FIXME: this is possible without resorting to the value stack */
double d1, d2;
d1 = DUK_TVAL_GET_NUMBER(tv_x);
duk_push_tval(ctx, tv_y);
duk_to_number(ctx, -1);
d2 = duk_require_number(ctx, -1);
duk_pop(ctx);
return duk_js_equals_number(d1, d2);
/* number/string-or-buffer -> coerce string to number (e.g. "'1.5' == 1.5" -> true) */
if (DUK_TVAL_IS_NUMBER(tv_x) && (DUK_TVAL_IS_STRING(tv_y) || DUK_TVAL_IS_BUFFER(tv_y))) {
/* the next 'if' is guaranteed to match after swap */
tv_tmp = tv_x;
tv_x = tv_y;
tv_y = tv_tmp;
}
if (DUK_TVAL_IS_STRING(tv_x) && DUK_TVAL_IS_NUMBER(tv_y)) {
if ((DUK_TVAL_IS_STRING(tv_x) || DUK_TVAL_IS_BUFFER(tv_x)) && DUK_TVAL_IS_NUMBER(tv_y)) {
/* FIXME: this is possible without resorting to the value stack */
double d1, d2;
d2 = DUK_TVAL_GET_NUMBER(tv_y);
duk_push_tval(ctx, tv_x);
duk_to_string(ctx, -1); /* buffer values are coerced first to string here */
duk_to_number(ctx, -1);
d1 = duk_require_number(ctx, -1);
duk_pop(ctx);
return duk_js_equals_number(d1, d2);
}
/* buffer/string -> compare contents */
if (DUK_TVAL_IS_BUFFER(tv_x) && DUK_TVAL_IS_STRING(tv_y)) {
tv_tmp = tv_x;
tv_x = tv_y;
tv_y = tv_tmp;
}
if (DUK_TVAL_IS_STRING(tv_x) && DUK_TVAL_IS_BUFFER(tv_y)) {
duk_hstring *h_x = DUK_TVAL_GET_STRING(tv_x);
duk_hbuffer *h_y = DUK_TVAL_GET_BUFFER(tv_y);
size_t len_x = DUK_HSTRING_GET_BYTELEN(h_x);
size_t len_y = DUK_HBUFFER_GET_SIZE(h_y);
void *buf_x;
void *buf_y;
if (len_x != len_y) {
return 0;
}
buf_x = (void *) DUK_HSTRING_GET_DATA(h_x);
buf_y = (void *) DUK_HBUFFER_GET_DATA_PTR(h_y);
/* if len_x == len_y == 0, buf_x and/or buf_y may
* be NULL, but that's OK.
*/
DUK_ASSERT(len_x == len_y);
DUK_ASSERT(len_x == 0 || buf_x != NULL);
DUK_ASSERT(len_y == 0 || buf_y != NULL);
return (DUK_MEMCMP(buf_x, buf_y, len_x) == 0) ? 1 : 0;
}
/* boolean/any -> coerce boolean to number and try again */
if (DUK_TVAL_IS_BOOLEAN(tv_x)) {
/* ToNumber(bool) is +1.0 or 0.0. Tagged boolean value is always 0 or 1. */
int rc;
DUK_ASSERT(DUK_TVAL_GET_BOOLEAN(tv_x) == 0 || DUK_TVAL_GET_BOOLEAN(tv_x) == 1);
duk_push_int(ctx, DUK_TVAL_GET_BOOLEAN(tv_x));
duk_push_tval(ctx, tv_y);
rc = duk_js_equals(thr, duk_get_tval(ctx, -2), duk_get_tval(ctx, -1));
duk_pop_2(ctx);
return rc;
tv_tmp = tv_x;
tv_x = tv_y;
tv_y = tv_tmp;
}
if (DUK_TVAL_IS_BOOLEAN(tv_y)) {
/* ToNumber(bool) is +1.0 or 0.0. Tagged boolean value is always 0 or 1. */
@ -552,19 +575,15 @@ int duk_js_equals(duk_hthread *thr, duk_tval *tv_x, duk_tval *tv_y) {
return rc;
}
/* string-or-number/object -> coerce object to primitive (apparently without hint), then try again */
if ((DUK_TVAL_IS_STRING(tv_x) || DUK_TVAL_IS_NUMBER(tv_x)) &&
/* string-number-buffer/object -> coerce object to primitive (apparently without hint), then try again */
if ((DUK_TVAL_IS_STRING(tv_x) || DUK_TVAL_IS_NUMBER(tv_x) || DUK_TVAL_IS_BUFFER(tv_x)) &&
DUK_TVAL_IS_OBJECT(tv_y)) {
int rc;
duk_push_tval(ctx, tv_x);
duk_push_tval(ctx, tv_y);
duk_to_primitive(ctx, -1, DUK_HINT_NONE); /* apparently no hint? */
rc = duk_js_equals(thr, duk_get_tval(ctx, -2), duk_get_tval(ctx, -1));
duk_pop_2(ctx);
return rc;
tv_tmp = tv_x;
tv_x = tv_y;
tv_y = tv_tmp;
}
if (DUK_TVAL_IS_OBJECT(tv_x) &&
(DUK_TVAL_IS_STRING(tv_y) || DUK_TVAL_IS_NUMBER(tv_y))) {
(DUK_TVAL_IS_STRING(tv_y) || DUK_TVAL_IS_NUMBER(tv_y) || DUK_TVAL_IS_BUFFER(tv_y))) {
int rc;
duk_push_tval(ctx, tv_x);
duk_push_tval(ctx, tv_y);
@ -574,9 +593,6 @@ int duk_js_equals(duk_hthread *thr, duk_tval *tv_x, duk_tval *tv_y) {
return rc;
}
/* FIXME: object vs. buffer: coerce object to primitive and retry? */
/* FIXME: string vs. buffer: compare contents? */
/* nothing worked -> not equal */
return 0;
}
@ -1148,7 +1164,7 @@ duk_hstring *duk_js_typeof(duk_hthread *thr, duk_tval *tv_x) {
}
case DUK_TAG_POINTER: {
/* implementation specific */
idx = DUK_STRIDX_POINTER;
idx = DUK_STRIDX_LC_POINTER;
break;
}
case DUK_TAG_STRING: {
@ -1167,7 +1183,7 @@ duk_hstring *duk_js_typeof(duk_hthread *thr, duk_tval *tv_x) {
}
case DUK_TAG_BUFFER: {
/* implementation specific */
idx = DUK_STRIDX_BUFFER;
idx = DUK_STRIDX_LC_BUFFER;
break;
}
default: {

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