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authorJohn Abd-El-Malek <jam@chromium.org>2014-06-23 15:24:28 -0700
committerJohn Abd-El-Malek <jam@chromium.org>2014-06-23 15:24:28 -0700
commit6c673585ed6bcb9e330ea5ab716f496c5d5f37b4 (patch)
tree0fd37d72e416fd2edb94373d18e08d6b8a33a303 /third_party/numerics/safe_conversions_impl.h
parent617089a3c1409be11fa130abb78dbd00b9e32d06 (diff)
downloadpdfium-6c673585ed6bcb9e330ea5ab716f496c5d5f37b4.tar.xz
Revert "Import Chromium base/numerics to resolve integer overflow."
This reverts commit d9713f05fdcecab8428d39034c6b84cd0bbd2920. This is breaking compile.
Diffstat (limited to 'third_party/numerics/safe_conversions_impl.h')
-rw-r--r--third_party/numerics/safe_conversions_impl.h217
1 files changed, 0 insertions, 217 deletions
diff --git a/third_party/numerics/safe_conversions_impl.h b/third_party/numerics/safe_conversions_impl.h
deleted file mode 100644
index a357e518d1..0000000000
--- a/third_party/numerics/safe_conversions_impl.h
+++ /dev/null
@@ -1,217 +0,0 @@
-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef BASE_SAFE_CONVERSIONS_IMPL_H_
-#define BASE_SAFE_CONVERSIONS_IMPL_H_
-
-#include <limits>
-
-#include "../macros.h"
-#include "../template_util.h"
-
-namespace base {
-namespace internal {
-
-// The std library doesn't provide a binary max_exponent for integers, however
-// we can compute one by adding one to the number of non-sign bits. This allows
-// for accurate range comparisons between floating point and integer types.
-template <typename NumericType>
-struct MaxExponent {
- static const int value = std::numeric_limits<NumericType>::is_iec559
- ? std::numeric_limits<NumericType>::max_exponent
- : (sizeof(NumericType) * 8 + 1 -
- std::numeric_limits<NumericType>::is_signed);
-};
-
-enum IntegerRepresentation {
- INTEGER_REPRESENTATION_UNSIGNED,
- INTEGER_REPRESENTATION_SIGNED
-};
-
-// A range for a given nunmeric Src type is contained for a given numeric Dst
-// type if both numeric_limits<Src>::max() <= numeric_limits<Dst>::max() and
-// numeric_limits<Src>::min() >= numeric_limits<Dst>::min() are true.
-// We implement this as template specializations rather than simple static
-// comparisons to ensure type correctness in our comparisons.
-enum NumericRangeRepresentation {
- NUMERIC_RANGE_NOT_CONTAINED,
- NUMERIC_RANGE_CONTAINED
-};
-
-// Helper templates to statically determine if our destination type can contain
-// maximum and minimum values represented by the source type.
-
-template <
- typename Dst,
- typename Src,
- IntegerRepresentation DstSign = std::numeric_limits<Dst>::is_signed
- ? INTEGER_REPRESENTATION_SIGNED
- : INTEGER_REPRESENTATION_UNSIGNED,
- IntegerRepresentation SrcSign =
- std::numeric_limits<Src>::is_signed
- ? INTEGER_REPRESENTATION_SIGNED
- : INTEGER_REPRESENTATION_UNSIGNED >
-struct StaticDstRangeRelationToSrcRange;
-
-// Same sign: Dst is guaranteed to contain Src only if its range is equal or
-// larger.
-template <typename Dst, typename Src, IntegerRepresentation Sign>
-struct StaticDstRangeRelationToSrcRange<Dst, Src, Sign, Sign> {
- static const NumericRangeRepresentation value =
- MaxExponent<Dst>::value >= MaxExponent<Src>::value
- ? NUMERIC_RANGE_CONTAINED
- : NUMERIC_RANGE_NOT_CONTAINED;
-};
-
-// Unsigned to signed: Dst is guaranteed to contain source only if its range is
-// larger.
-template <typename Dst, typename Src>
-struct StaticDstRangeRelationToSrcRange<Dst,
- Src,
- INTEGER_REPRESENTATION_SIGNED,
- INTEGER_REPRESENTATION_UNSIGNED> {
- static const NumericRangeRepresentation value =
- MaxExponent<Dst>::value > MaxExponent<Src>::value
- ? NUMERIC_RANGE_CONTAINED
- : NUMERIC_RANGE_NOT_CONTAINED;
-};
-
-// Signed to unsigned: Dst cannot be statically determined to contain Src.
-template <typename Dst, typename Src>
-struct StaticDstRangeRelationToSrcRange<Dst,
- Src,
- INTEGER_REPRESENTATION_UNSIGNED,
- INTEGER_REPRESENTATION_SIGNED> {
- static const NumericRangeRepresentation value = NUMERIC_RANGE_NOT_CONTAINED;
-};
-
-enum RangeConstraint {
- RANGE_VALID = 0x0, // Value can be represented by the destination type.
- RANGE_UNDERFLOW = 0x1, // Value would overflow.
- RANGE_OVERFLOW = 0x2, // Value would underflow.
- RANGE_INVALID = RANGE_UNDERFLOW | RANGE_OVERFLOW // Invalid (i.e. NaN).
-};
-
-// Helper function for coercing an int back to a RangeContraint.
-inline RangeConstraint GetRangeConstraint(int integer_range_constraint) {
- assert(integer_range_constraint >= RANGE_VALID &&
- integer_range_constraint <= RANGE_INVALID);
- return static_cast<RangeConstraint>(integer_range_constraint);
-}
-
-// This function creates a RangeConstraint from an upper and lower bound
-// check by taking advantage of the fact that only NaN can be out of range in
-// both directions at once.
-inline RangeConstraint GetRangeConstraint(bool is_in_upper_bound,
- bool is_in_lower_bound) {
- return GetRangeConstraint((is_in_upper_bound ? 0 : RANGE_OVERFLOW) |
- (is_in_lower_bound ? 0 : RANGE_UNDERFLOW));
-}
-
-template <
- typename Dst,
- typename Src,
- IntegerRepresentation DstSign = std::numeric_limits<Dst>::is_signed
- ? INTEGER_REPRESENTATION_SIGNED
- : INTEGER_REPRESENTATION_UNSIGNED,
- IntegerRepresentation SrcSign = std::numeric_limits<Src>::is_signed
- ? INTEGER_REPRESENTATION_SIGNED
- : INTEGER_REPRESENTATION_UNSIGNED,
- NumericRangeRepresentation DstRange =
- StaticDstRangeRelationToSrcRange<Dst, Src>::value >
-struct DstRangeRelationToSrcRangeImpl;
-
-// The following templates are for ranges that must be verified at runtime. We
-// split it into checks based on signedness to avoid confusing casts and
-// compiler warnings on signed an unsigned comparisons.
-
-// Dst range is statically determined to contain Src: Nothing to check.
-template <typename Dst,
- typename Src,
- IntegerRepresentation DstSign,
- IntegerRepresentation SrcSign>
-struct DstRangeRelationToSrcRangeImpl<Dst,
- Src,
- DstSign,
- SrcSign,
- NUMERIC_RANGE_CONTAINED> {
- static RangeConstraint Check(Src value) { return RANGE_VALID; }
-};
-
-// Signed to signed narrowing: Both the upper and lower boundaries may be
-// exceeded.
-template <typename Dst, typename Src>
-struct DstRangeRelationToSrcRangeImpl<Dst,
- Src,
- INTEGER_REPRESENTATION_SIGNED,
- INTEGER_REPRESENTATION_SIGNED,
- NUMERIC_RANGE_NOT_CONTAINED> {
- static RangeConstraint Check(Src value) {
- return std::numeric_limits<Dst>::is_iec559
- ? GetRangeConstraint(value <= std::numeric_limits<Dst>::max(),
- value >= -std::numeric_limits<Dst>::max())
- : GetRangeConstraint(value <= std::numeric_limits<Dst>::max(),
- value >= std::numeric_limits<Dst>::min());
- }
-};
-
-// Unsigned to unsigned narrowing: Only the upper boundary can be exceeded.
-template <typename Dst, typename Src>
-struct DstRangeRelationToSrcRangeImpl<Dst,
- Src,
- INTEGER_REPRESENTATION_UNSIGNED,
- INTEGER_REPRESENTATION_UNSIGNED,
- NUMERIC_RANGE_NOT_CONTAINED> {
- static RangeConstraint Check(Src value) {
- return GetRangeConstraint(value <= std::numeric_limits<Dst>::max(), true);
- }
-};
-
-// Unsigned to signed: The upper boundary may be exceeded.
-template <typename Dst, typename Src>
-struct DstRangeRelationToSrcRangeImpl<Dst,
- Src,
- INTEGER_REPRESENTATION_SIGNED,
- INTEGER_REPRESENTATION_UNSIGNED,
- NUMERIC_RANGE_NOT_CONTAINED> {
- static RangeConstraint Check(Src value) {
- return sizeof(Dst) > sizeof(Src)
- ? RANGE_VALID
- : GetRangeConstraint(
- value <= static_cast<Src>(std::numeric_limits<Dst>::max()),
- true);
- }
-};
-
-// Signed to unsigned: The upper boundary may be exceeded for a narrower Dst,
-// and any negative value exceeds the lower boundary.
-template <typename Dst, typename Src>
-struct DstRangeRelationToSrcRangeImpl<Dst,
- Src,
- INTEGER_REPRESENTATION_UNSIGNED,
- INTEGER_REPRESENTATION_SIGNED,
- NUMERIC_RANGE_NOT_CONTAINED> {
- static RangeConstraint Check(Src value) {
- return (MaxExponent<Dst>::value >= MaxExponent<Src>::value)
- ? GetRangeConstraint(true, value >= static_cast<Src>(0))
- : GetRangeConstraint(
- value <= static_cast<Src>(std::numeric_limits<Dst>::max()),
- value >= static_cast<Src>(0));
- }
-};
-
-template <typename Dst, typename Src>
-inline RangeConstraint DstRangeRelationToSrcRange(Src value) {
- COMPILE_ASSERT(std::numeric_limits<Src>::is_specialized,
- argument_must_be_numeric);
- COMPILE_ASSERT(std::numeric_limits<Dst>::is_specialized,
- result_must_be_numeric);
- return DstRangeRelationToSrcRangeImpl<Dst, Src>::Check(value);
-}
-
-} // namespace internal
-} // namespace base
-
-#endif // BASE_SAFE_CONVERSIONS_IMPL_H_
-