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authorTom Sepez <tsepez@chromium.org>2018-09-13 17:41:52 +0000
committerChromium commit bot <commit-bot@chromium.org>2018-09-13 17:41:52 +0000
commita5d7ad3aa8feb08a14b5cca173d673054c1ade23 (patch)
tree259f0c17f5b7a2e09f80948f8b5cc8a04fdb7874 /core/fxcrt
parentaebace3bd14eaf72d43f63d90700cd1b0fa049ca (diff)
downloadpdfium-a5d7ad3aa8feb08a14b5cca173d673054c1ade23.tar.xz
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>
Diffstat (limited to 'core/fxcrt')
-rw-r--r--core/fxcrt/fx_number.cpp104
-rw-r--r--core/fxcrt/fx_number.h39
-rw-r--r--core/fxcrt/fx_number_unittest.cpp165
-rw-r--r--core/fxcrt/fx_string.cpp63
-rw-r--r--core/fxcrt/fx_string.h3
-rw-r--r--core/fxcrt/fx_string_unittest.cpp47
6 files changed, 310 insertions, 111 deletions
diff --git a/core/fxcrt/fx_number.cpp b/core/fxcrt/fx_number.cpp
new file mode 100644
index 0000000000..68d5bd9b32
--- /dev/null
+++ b/core/fxcrt/fx_number.cpp
@@ -0,0 +1,104 @@
+// 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);
+}
diff --git a/core/fxcrt/fx_number.h b/core/fxcrt/fx_number.h
new file mode 100644
index 0000000000..4c789b4130
--- /dev/null
+++ b/core/fxcrt/fx_number.h
@@ -0,0 +1,39 @@
+// 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
+
+#ifndef CORE_FXCRT_FX_NUMBER_H_
+#define CORE_FXCRT_FX_NUMBER_H_
+
+#include <stdint.h>
+
+#include "core/fxcrt/bytestring.h"
+
+class FX_Number {
+ public:
+ FX_Number();
+ explicit FX_Number(uint32_t value);
+ explicit FX_Number(int32_t value);
+ explicit FX_Number(float value);
+ explicit FX_Number(const ByteStringView& str);
+
+ bool IsInteger() const { return m_bInteger; }
+ bool IsSigned() const { return m_bSigned; }
+
+ uint32_t GetUnsigned() const; // Underflow possible.
+ int32_t GetSigned() const; // Underflow/Overflow possible.
+ float GetFloat() const;
+
+ private:
+ bool m_bInteger; // One of the two integers vs. float type.
+ bool m_bSigned; // Only valid if |m_bInteger|.
+ union {
+ uint32_t m_UnsignedValue;
+ int32_t m_SignedValue;
+ float m_FloatValue;
+ };
+};
+
+#endif // CORE_FXCRT_FX_NUMBER_H_
diff --git a/core/fxcrt/fx_number_unittest.cpp b/core/fxcrt/fx_number_unittest.cpp
new file mode 100644
index 0000000000..83702dadcf
--- /dev/null
+++ b/core/fxcrt/fx_number_unittest.cpp
@@ -0,0 +1,165 @@
+// 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.
+
+#include <limits>
+
+#include "core/fxcrt/fx_number.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(fxnumber, Default) {
+ FX_Number number;
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_FALSE(number.IsSigned());
+ EXPECT_EQ(0u, number.GetUnsigned());
+ EXPECT_EQ(0, number.GetSigned());
+ EXPECT_FLOAT_EQ(0.0f, number.GetFloat());
+}
+
+TEST(fxnumber, FromUnsigned) {
+ FX_Number number(42u);
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_FALSE(number.IsSigned());
+ EXPECT_EQ(42u, number.GetUnsigned());
+ EXPECT_EQ(42, number.GetSigned());
+ EXPECT_FLOAT_EQ(42.0f, number.GetFloat());
+
+ // Show that assignment works.
+ FX_Number number2 = number;
+ EXPECT_TRUE(number2.IsInteger());
+ EXPECT_FALSE(number2.IsSigned());
+ EXPECT_EQ(42u, number2.GetUnsigned());
+ EXPECT_EQ(42, number2.GetSigned());
+ EXPECT_FLOAT_EQ(42.0F, number2.GetFloat());
+}
+
+TEST(fxnumber, FromSigned) {
+ FX_Number number(-128);
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_TRUE(number.IsSigned());
+ EXPECT_EQ(4294967168u, number.GetUnsigned());
+ EXPECT_EQ(-128, number.GetSigned());
+ EXPECT_FLOAT_EQ(-128.0f, number.GetFloat());
+
+ // Show that assignment works.
+ FX_Number number2 = number;
+ EXPECT_TRUE(number2.IsInteger());
+ EXPECT_TRUE(number2.IsSigned());
+ EXPECT_EQ(4294967168u, number2.GetUnsigned());
+ EXPECT_EQ(-128, number2.GetSigned());
+ EXPECT_FLOAT_EQ(-128.0f, number2.GetFloat());
+}
+
+TEST(fxnumber, FromFloat) {
+ FX_Number number(-100.001f);
+ EXPECT_FALSE(number.IsInteger());
+ EXPECT_TRUE(number.IsSigned());
+ EXPECT_EQ(4294967196u, number.GetUnsigned());
+ EXPECT_EQ(-100, number.GetSigned());
+ EXPECT_FLOAT_EQ(-100.001f, number.GetFloat());
+
+ // Show that assignment works.
+ FX_Number number2 = number;
+ EXPECT_FALSE(number2.IsInteger());
+ EXPECT_TRUE(number2.IsSigned());
+ EXPECT_EQ(4294967196u, number2.GetUnsigned());
+ EXPECT_EQ(-100, number2.GetSigned());
+ EXPECT_FLOAT_EQ(-100.001f, number2.GetFloat());
+}
+
+TEST(fxnumber, FromStringUnsigned) {
+ {
+ FX_Number number("");
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_FALSE(number.IsSigned());
+ EXPECT_EQ(0u, number.GetUnsigned());
+ }
+ {
+ FX_Number number("0");
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_FALSE(number.IsSigned());
+ EXPECT_EQ(0u, number.GetUnsigned());
+ }
+ {
+ FX_Number number("10");
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_FALSE(number.IsSigned());
+ EXPECT_EQ(10u, number.GetUnsigned());
+ }
+ {
+ FX_Number number("4294967295");
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_FALSE(number.IsSigned());
+ EXPECT_EQ(std::numeric_limits<uint32_t>::max(), number.GetUnsigned());
+ }
+ {
+ // Value overflows.
+ FX_Number number("4223423494965252");
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_FALSE(number.IsSigned());
+ EXPECT_EQ(0u, number.GetUnsigned());
+ }
+ {
+ // No explicit sign will allow the number to go negative if we retrieve
+ // it as a signed value. This is needed for things like the encryption
+ // Permissions flag (Table 3.20 PDF 1.7 spec)
+ FX_Number number("4294965252");
+ EXPECT_EQ(-2044, number.GetSigned());
+ }
+}
+
+TEST(fxnumber, FromStringSigned) {
+ {
+ FX_Number number("-0");
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_TRUE(number.IsSigned());
+ EXPECT_EQ(0, number.GetSigned());
+ }
+ {
+ FX_Number number("+0");
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_TRUE(number.IsSigned());
+ EXPECT_EQ(0, number.GetSigned());
+ }
+ {
+ FX_Number number("-10");
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_TRUE(number.IsSigned());
+ EXPECT_EQ(-10, number.GetSigned());
+ }
+ {
+ FX_Number number("+10");
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_TRUE(number.IsSigned());
+ EXPECT_EQ(10, number.GetSigned());
+ }
+ {
+ FX_Number number("-2147483648");
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_TRUE(number.IsSigned());
+ EXPECT_EQ(std::numeric_limits<int32_t>::min(), number.GetSigned());
+ }
+ {
+ FX_Number number("+2147483647");
+ EXPECT_TRUE(number.IsInteger());
+ EXPECT_TRUE(number.IsSigned());
+ EXPECT_EQ(std::numeric_limits<int32_t>::max(), number.GetSigned());
+ }
+ {
+ // Value underflows.
+ FX_Number number("-2147483649");
+ EXPECT_EQ(0u, number.GetUnsigned());
+ EXPECT_EQ(0, number.GetSigned());
+ }
+ {
+ // Value overflows.
+ FX_Number number("+2147483648");
+ EXPECT_EQ(0u, number.GetUnsigned());
+ EXPECT_EQ(0, number.GetSigned());
+ }
+}
+
+TEST(fxnumber, FromStringFloat) {
+ FX_Number number("3.24");
+ EXPECT_FLOAT_EQ(3.24f, number.GetFloat());
+}
diff --git a/core/fxcrt/fx_string.cpp b/core/fxcrt/fx_string.cpp
index c9993f9ab8..31eb8e917d 100644
--- a/core/fxcrt/fx_string.cpp
+++ b/core/fxcrt/fx_string.cpp
@@ -47,69 +47,6 @@ float FractionalScale(size_t scale_factor, int value) {
} // namespace
-bool FX_atonum(const ByteStringView& strc, void* pData) {
- if (strc.Contains('.')) {
- float* pFloat = static_cast<float*>(pData);
- *pFloat = FX_atof(strc);
- return false;
- }
-
- // 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> integer = 0;
- bool bNegative = false;
- bool bSigned = false;
- size_t cc = 0;
- if (strc[0] == '+') {
- cc++;
- bSigned = true;
- } else if (strc[0] == '-') {
- bNegative = true;
- bSigned = true;
- cc++;
- }
-
- while (cc < strc.GetLength() && std::isdigit(strc[cc])) {
- integer = integer * 10 + FXSYS_DecimalCharToInt(strc.CharAt(cc));
- if (!integer.IsValid())
- break;
- cc++;
- }
-
- // We have a sign, and the value was greater then a regular integer
- // we've overflowed, reset to the default value.
- if (bSigned) {
- if (bNegative) {
- if (integer.ValueOrDefault(0) >
- static_cast<uint32_t>(std::numeric_limits<int>::max()) + 1) {
- integer = 0;
- }
- } else if (integer.ValueOrDefault(0) >
- static_cast<uint32_t>(std::numeric_limits<int>::max())) {
- integer = 0;
- }
- }
-
- // Switch back to the int space so we can flip to a negative if we need.
- uint32_t uValue = integer.ValueOrDefault(0);
- int32_t value = static_cast<int>(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
- // integer cannot represent 2147483648.
- static constexpr int kMinInt = std::numeric_limits<int>::min();
- value = LIKELY(value != kMinInt) ? -value : kMinInt;
- }
-
- int* pInt = static_cast<int*>(pData);
- *pInt = value;
- return true;
-}
-
float FX_atof(const ByteStringView& strc) {
if (strc.IsEmpty())
return 0.0;
diff --git a/core/fxcrt/fx_string.h b/core/fxcrt/fx_string.h
index 2cf823738a..670aa4d4b7 100644
--- a/core/fxcrt/fx_string.h
+++ b/core/fxcrt/fx_string.h
@@ -7,6 +7,8 @@
#ifndef CORE_FXCRT_FX_STRING_H_
#define CORE_FXCRT_FX_STRING_H_
+#include <stdint.h>
+
#include "core/fxcrt/bytestring.h"
#include "core/fxcrt/widestring.h"
@@ -19,7 +21,6 @@ WideString FX_UTF8Decode(const ByteStringView& bsStr);
float FX_atof(const ByteStringView& str);
float FX_atof(const WideStringView& wsStr);
-bool FX_atonum(const ByteStringView& str, void* pData);
size_t FX_ftoa(float f, char* buf);
#endif // CORE_FXCRT_FX_STRING_H_
diff --git a/core/fxcrt/fx_string_unittest.cpp b/core/fxcrt/fx_string_unittest.cpp
index 60e7f07523..3059de3e5c 100644
--- a/core/fxcrt/fx_string_unittest.cpp
+++ b/core/fxcrt/fx_string_unittest.cpp
@@ -2,56 +2,9 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
-#include <limits>
-
#include "core/fxcrt/fx_string.h"
#include "testing/gtest/include/gtest/gtest.h"
-TEST(fxstring, FX_atonum) {
- int i;
- EXPECT_TRUE(FX_atonum("10", &i));
- EXPECT_EQ(10, i);
-
- EXPECT_TRUE(FX_atonum("-10", &i));
- EXPECT_EQ(-10, i);
-
- EXPECT_TRUE(FX_atonum("+10", &i));
- EXPECT_EQ(10, i);
-
- EXPECT_TRUE(FX_atonum("-2147483648", &i));
- EXPECT_EQ(std::numeric_limits<int>::min(), i);
-
- EXPECT_TRUE(FX_atonum("2147483647", &i));
- EXPECT_EQ(2147483647, i);
-
- // Value overflows.
- EXPECT_TRUE(FX_atonum("-2147483649", &i));
- EXPECT_EQ(0, i);
-
- // Value overflows.
- EXPECT_TRUE(FX_atonum("+2147483648", &i));
- EXPECT_EQ(0, i);
-
- // Value overflows.
- EXPECT_TRUE(FX_atonum("4223423494965252", &i));
- EXPECT_EQ(0, i);
-
- // No explicit sign will allow the number to go negative. This is for things
- // like the encryption Permissions flag (Table 3.20 PDF 1.7 spec)
- EXPECT_TRUE(FX_atonum("4294965252", &i));
- EXPECT_EQ(-2044, i);
-
- EXPECT_TRUE(FX_atonum("-4294965252", &i));
- EXPECT_EQ(0, i);
-
- EXPECT_TRUE(FX_atonum("+4294965252", &i));
- EXPECT_EQ(0, i);
-
- float f;
- EXPECT_FALSE(FX_atonum("3.24", &f));
- EXPECT_FLOAT_EQ(3.24f, f);
-}
-
TEST(fxstring, FX_UTF8Encode) {
EXPECT_EQ("", FX_UTF8Encode(WideStringView()));
EXPECT_EQ(