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JS/js/jsparse.c  view on Meta::CPAN

	    js_strncpy(chars + length1, str2->chars, length2);
	    chars[length] = 0;
	    pn->pn_atom = js_AtomizeChars(cx, chars, length, 0);
	    if (!pn->pn_atom)
		return JS_FALSE;
	    PR_ARENA_RELEASE(&cx->tempPool, mark);
	    pn->pn_type = TOK_STRING;
	    pn->pn_op = JSOP_STRING;
	    pn->pn_arity = PN_NULLARY;
	    break;
	}
	/* FALL THROUGH */

      case TOK_SHOP:
      case TOK_MINUS:
      case TOK_STAR:
      case TOK_DIVOP:
	if (pn1->pn_type == TOK_NUMBER && pn2->pn_type == TOK_NUMBER) {
	    jsdouble d, d2;
	    int32 i, j;
	    uint32 u;

	    /* Fold two numeric constants. */
	    d = pn1->pn_dval;
	    d2 = pn2->pn_dval;
	    switch (pn->pn_op) {
	      case JSOP_LSH:
	      case JSOP_RSH:
		if (!js_DoubleToECMAInt32(cx, d, &i))
		    return JS_FALSE;
		if (!js_DoubleToECMAInt32(cx, d2, &j))
		    return JS_FALSE;
		j &= 31;
		d = (pn->pn_op == JSOP_LSH) ? i << j : i >> j;
		break;

	      case JSOP_URSH:
		if (!js_DoubleToECMAUint32(cx, d, &u))
		    return JS_FALSE;
		if (!js_DoubleToECMAInt32(cx, d2, &j))
		    return JS_FALSE;
		j &= 31;
		d = u >> j;
		break;

	      case JSOP_ADD:
		d += d2;
		break;

	      case JSOP_SUB:
		d -= d2;
		break;

	      case JSOP_MUL:
		d *= d2;
		break;

	      case JSOP_DIV:
		if (d2 == 0) {
#ifdef XP_PC
		    /* XXX MSVC miscompiles such that (NaN == 0) */
		    if (JSDOUBLE_IS_NaN(d2))
			d = *cx->runtime->jsNaN;
		    else
#endif
		    if (d == 0 || JSDOUBLE_IS_NaN(d))
			d = *cx->runtime->jsNaN;
		    else if ((JSDOUBLE_HI32(d) ^ JSDOUBLE_HI32(d2)) >> 31)
			d = *cx->runtime->jsNegativeInfinity;
		    else
			d = *cx->runtime->jsPositiveInfinity;
		} else {
		    d /= d2;
		}
		break;

	      case JSOP_MOD:
		if (d2 == 0) {
		    d = *cx->runtime->jsNaN;
		} else {
#ifdef XP_PC
		  /* Workaround MS fmod bug where 42 % (1/0) => NaN, not 42. */
		  if (!(JSDOUBLE_IS_FINITE(d) && JSDOUBLE_IS_INFINITE(d2)))
#endif
		    d = fmod(d, d2);
		}
		break;

	      default:;
	    }
	    pn->pn_type = TOK_NUMBER;
	    pn->pn_op = JSOP_NUMBER;
	    pn->pn_arity = PN_NULLARY;
	    pn->pn_dval = d;
	}
	break;

      case TOK_UNARYOP:
	if (pn1->pn_type == TOK_NUMBER) {
	    jsdouble d;
	    int32 i;

	    /* Operate on one numeric constants. */
	    d = pn1->pn_dval;
	    switch (pn->pn_op) {
	      case JSOP_BITNOT:
		if (!js_DoubleToECMAInt32(cx, d, &i))
		    return JS_FALSE;
		d = ~i;
	      	break;

	      case JSOP_NEG:
		d = -d;
	      	break;

	      case JSOP_POS:
	      	break;

	      case JSOP_NOT:
		pn->pn_type = TOK_PRIMARY;
		pn->pn_op = (d == 0) ? JSOP_TRUE : JSOP_FALSE;
		pn->pn_arity = PN_NULLARY;
	      	/* FALL THROUGH */

	      default:
		/* Return early to dodge the common TOK_NUMBER code. */
		return JS_TRUE;
	    }
	    pn->pn_type = TOK_NUMBER;
	    pn->pn_op = JSOP_NUMBER;
	    pn->pn_arity = PN_NULLARY;
	    pn->pn_dval = d;
	}
	break;

      default:;
    }

    return JS_TRUE;
}