dom/xslt/xpath/txNumberExpr.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "mozilla/FloatingPoint.h"
   7
   8 #include "txExpr.h"
   9 #include <math.h>
  10 #include "txIXPathContext.h"
  11
  12 nsresult txNumberExpr::evaluate(txIEvalContext* aContext,
  13                                 txAExprResult** aResult) {
  14   *aResult = nullptr;
  15
  16   RefPtr<txAExprResult> exprRes;
  17   nsresult rv = mRightExpr->evaluate(aContext, getter_AddRefs(exprRes));
  18   NS_ENSURE_SUCCESS(rv, rv);
  19
  20   double rightDbl = exprRes->numberValue();
  21
  22   rv = mLeftExpr->evaluate(aContext, getter_AddRefs(exprRes));
  23   NS_ENSURE_SUCCESS(rv, rv);
  24
  25   double leftDbl = exprRes->numberValue();
  26   double result = 0;
  27
  28   switch (mOp) {
  29     case ADD:
  30       result = leftDbl + rightDbl;
  31       break;
  32
  33     case SUBTRACT:
  34       result = leftDbl - rightDbl;
  35       break;
  36
  37     case DIVIDE:
  38       if (rightDbl == 0) {
  39 #if defined(XP_WIN)
  40         /* XXX MSVC miscompiles such that (NaN == 0) */
  41         if (std::isnan(rightDbl))
  42           result = mozilla::UnspecifiedNaN<double>();
  43         else
  44 #endif
  45             if (leftDbl == 0 || std::isnan(leftDbl))
  46           result = mozilla::UnspecifiedNaN<double>();
  47         else if (mozilla::IsNegative(leftDbl) != mozilla::IsNegative(rightDbl))
  48           result = mozilla::NegativeInfinity<double>();
  49         else
  50           result = mozilla::PositiveInfinity<double>();
  51       } else
  52         result = leftDbl / rightDbl;
  53       break;
  54
  55     case MODULUS:
  56       if (rightDbl == 0) {
  57         result = mozilla::UnspecifiedNaN<double>();
  58       } else {
  59 #if defined(XP_WIN)
  60         /* Workaround MS fmod bug where 42 % (1/0) => NaN, not 42. */
  61         if (!std::isinf(leftDbl) && std::isinf(rightDbl))
  62           result = leftDbl;
  63         else
  64 #endif
  65           result = fmod(leftDbl, rightDbl);
  66       }
  67       break;
  68
  69     case MULTIPLY:
  70       result = leftDbl * rightDbl;
  71       break;
  72   }
  73
  74   return aContext->recycler()->getNumberResult(result, aResult);
  75 }  //-- evaluate
  76
  77 TX_IMPL_EXPR_STUBS_2(txNumberExpr, NUMBER_RESULT, mLeftExpr, mRightExpr)
  78
  79 bool txNumberExpr::isSensitiveTo(ContextSensitivity aContext) {
  80   return mLeftExpr->isSensitiveTo(aContext) ||
  81          mRightExpr->isSensitiveTo(aContext);
  82 }
  83
  84 #ifdef TX_TO_STRING
  85 void txNumberExpr::toString(nsAString& str) {
  86   mLeftExpr->toString(str);
  87
  88   switch (mOp) {
  89     case ADD:
  90       str.AppendLiteral(" + ");
  91       break;
  92     case SUBTRACT:
  93       str.AppendLiteral(" - ");
  94       break;
  95     case DIVIDE:
  96       str.AppendLiteral(" div ");
  97       break;
  98     case MODULUS:
  99       str.AppendLiteral(" mod ");
 100       break;
 101     case MULTIPLY:
 102       str.AppendLiteral(" * ");
 103       break;
 104   }
 105
 106   mRightExpr->toString(str);
 107 }
 108 #endif