tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

txNumberExpr.cpp (2855B)

      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 <math.h>
      7 
      8 #include "mozilla/FloatingPoint.h"
      9 #include "txExpr.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