gecko-dev/dom/xslt/xpath/txNumberExpr.cpp

117 строки
3.2 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/FloatingPoint.h"
#include "txExpr.h"
#include <math.h>
#include "txIXPathContext.h"
nsresult
txNumberExpr::evaluate(txIEvalContext* aContext, txAExprResult** aResult)
{
*aResult = nullptr;
RefPtr<txAExprResult> exprRes;
nsresult rv = mRightExpr->evaluate(aContext, getter_AddRefs(exprRes));
NS_ENSURE_SUCCESS(rv, rv);
double rightDbl = exprRes->numberValue();
rv = mLeftExpr->evaluate(aContext, getter_AddRefs(exprRes));
NS_ENSURE_SUCCESS(rv, rv);
double leftDbl = exprRes->numberValue();
double result = 0;
switch (mOp) {
case ADD:
result = leftDbl + rightDbl;
break;
case SUBTRACT:
result = leftDbl - rightDbl;
break;
case DIVIDE:
if (rightDbl == 0) {
#if defined(XP_WIN)
/* XXX MSVC miscompiles such that (NaN == 0) */
if (mozilla::IsNaN(rightDbl))
result = mozilla::UnspecifiedNaN<double>();
else
#endif
if (leftDbl == 0 || mozilla::IsNaN(leftDbl))
result = mozilla::UnspecifiedNaN<double>();
else if (mozilla::IsNegative(leftDbl) != mozilla::IsNegative(rightDbl))
result = mozilla::NegativeInfinity<double>();
else
result = mozilla::PositiveInfinity<double>();
}
else
result = leftDbl / rightDbl;
break;
case MODULUS:
if (rightDbl == 0) {
result = mozilla::UnspecifiedNaN<double>();
}
else {
#if defined(XP_WIN)
/* Workaround MS fmod bug where 42 % (1/0) => NaN, not 42. */
if (!mozilla::IsInfinite(leftDbl) && mozilla::IsInfinite(rightDbl))
result = leftDbl;
else
#endif
result = fmod(leftDbl, rightDbl);
}
break;
case MULTIPLY:
result = leftDbl * rightDbl;
break;
}
return aContext->recycler()->getNumberResult(result, aResult);
} //-- evaluate
TX_IMPL_EXPR_STUBS_2(txNumberExpr, NUMBER_RESULT, mLeftExpr, mRightExpr)
bool
txNumberExpr::isSensitiveTo(ContextSensitivity aContext)
{
return mLeftExpr->isSensitiveTo(aContext) ||
mRightExpr->isSensitiveTo(aContext);
}
#ifdef TX_TO_STRING
void
txNumberExpr::toString(nsAString& str)
{
mLeftExpr->toString(str);
switch (mOp) {
case ADD:
str.AppendLiteral(" + ");
break;
case SUBTRACT:
str.AppendLiteral(" - ");
break;
case DIVIDE:
str.AppendLiteral(" div ");
break;
case MODULUS:
str.AppendLiteral(" mod ");
break;
case MULTIPLY:
str.AppendLiteral(" * ");
break;
}
mRightExpr->toString(str);
}
#endif