Revert "Introduce FX_Number class as a replacement for FX_atonum()."

This reverts commit a5d7ad3aa8feb08a14b5cca173d673054c1ade23.

Reason for revert: Speculative revert to get back before flake.

Original change's description:
> Introduce FX_Number class as a replacement for FX_atonum().
> 
> The issue with FX_atonum() is that it doesn't return any information
> about whether it range-checked its integer values as a signed or
> unsigned type, even though it knows this as part of its processing.
> 
> Rather than adding another out parameter to that function, create
> a class to hold all this information together.
> 
> This is the first place things went astray while diagnosing
> bug 882959, in that a large positive value was cast to float as a
> negative value. Unfortunately, this doesn't affect the related bug,
> but is a step in the right direction.
> 
> Change-Id: I0977ec8fccf85e2632a962507bdd30a1cbe6d33c
> Reviewed-on: https://pdfium-review.googlesource.com/42353
> Reviewed-by: Lei Zhang <thestig@chromium.org>
> Commit-Queue: Tom Sepez <tsepez@chromium.org>

TBR=thestig@chromium.org,tsepez@chromium.org

Change-Id: Ia56270c3daa80408fc2b23eb4384a77f03f45b82
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://pdfium-review.googlesource.com/42392
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

1 files changed, 0 insertions, 104 deletions

diff --git a/core/fxcrt/fx_number.cpp b/core/fxcrt/fx_number.cpp
deleted file mode 100644
index 68d5bd9b32..0000000000
--- a/core/fxcrt/fx_number.cpp
+++ /dev/null
@@ -1,104 +0,0 @@
-// Copyright 2018 PDFium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
-
-#include "core/fxcrt/fx_number.h"
-
-#include <limits>
-
-#include "core/fxcrt/fx_extension.h"
-#include "core/fxcrt/fx_string.h"
-
-FX_Number::FX_Number()
-    : m_bInteger(true), m_bSigned(false), m_UnsignedValue(0) {}
-
-FX_Number::FX_Number(uint32_t value)
-    : m_bInteger(true), m_bSigned(false), m_UnsignedValue(value) {}
-
-FX_Number::FX_Number(int32_t value)
-    : m_bInteger(true), m_bSigned(true), m_SignedValue(value) {}
-
-FX_Number::FX_Number(float value)
-    : m_bInteger(false), m_bSigned(true), m_FloatValue(value) {}
-
-FX_Number::FX_Number(const ByteStringView& strc)
-    : m_bInteger(true), m_bSigned(false), m_UnsignedValue(0) {
-  if (strc.IsEmpty())
-    return;
-
-  if (strc.Contains('.')) {
-    m_bInteger = false;
-    m_bSigned = true;
-    m_FloatValue = FX_atof(strc);
-    return;
-  }
-
-  // Note, numbers in PDF are typically of the form 123, -123, etc. But,
-  // for things like the Permissions on the encryption hash the number is
-  // actually an unsigned value. We use a uint32_t so we can deal with the
-  // unsigned and then check for overflow if the user actually signed the value.
-  // The Permissions flag is listed in Table 3.20 PDF 1.7 spec.
-  pdfium::base::CheckedNumeric<uint32_t> unsigned_val = 0;
-  bool bNegative = false;
-  size_t cc = 0;
-  if (strc[0] == '+') {
-    cc++;
-    m_bSigned = true;
-  } else if (strc[0] == '-') {
-    bNegative = true;
-    m_bSigned = true;
-    cc++;
-  }
-
-  while (cc < strc.GetLength() && std::isdigit(strc[cc])) {
-    unsigned_val = unsigned_val * 10 + FXSYS_DecimalCharToInt(strc.CharAt(cc));
-    if (!unsigned_val.IsValid())
-      break;
-    cc++;
-  }
-
-  uint32_t uValue = unsigned_val.ValueOrDefault(0);
-  if (!m_bSigned) {
-    m_UnsignedValue = uValue;
-    return;
-  }
-
-  // We have a sign, so if the value was greater then the signed integer
-  // limits, then we've overflowed and must reset to the default value.
-  constexpr uint32_t uLimit =
-      static_cast<uint32_t>(std::numeric_limits<int>::max());
-
-  if (uValue > (bNegative ? uLimit + 1 : uLimit))
-    uValue = 0;
-
-  // Switch back to the int space so we can flip to a negative if we need.
-  int32_t value = static_cast<int32_t>(uValue);
-  if (bNegative) {
-    // |value| is usually positive, except in the corner case of "-2147483648",
-    // where |uValue| is 2147483648. When it gets casted to an int, |value|
-    // becomes -2147483648. For this case, avoid undefined behavior, because
-    // an int32_t cannot represent 2147483648.
-    static constexpr int kMinInt = std::numeric_limits<int>::min();
-    m_SignedValue = LIKELY(value != kMinInt) ? -value : kMinInt;
-  } else {
-    m_SignedValue = value;
-  }
-}
-
-uint32_t FX_Number::GetUnsigned() const {
-  return m_bInteger ? m_UnsignedValue : static_cast<uint32_t>(m_FloatValue);
-}
-
-int32_t FX_Number::GetSigned() const {
-  return m_bInteger ? m_SignedValue : static_cast<int32_t>(m_FloatValue);
-}
-
-float FX_Number::GetFloat() const {
-  if (!m_bInteger)
-    return m_FloatValue;
-
-  return m_bSigned ? static_cast<float>(m_SignedValue)
-                   : static_cast<float>(m_UnsignedValue);
-}