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Diffstat (limited to 'chromium/base/safe_numerics.h')
-rw-r--r-- | chromium/base/safe_numerics.h | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/chromium/base/safe_numerics.h b/chromium/base/safe_numerics.h deleted file mode 100644 index ce5c72fcc77..00000000000 --- a/chromium/base/safe_numerics.h +++ /dev/null @@ -1,135 +0,0 @@ -// Copyright 2013 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_NUMERICS_H_ -#define BASE_SAFE_NUMERICS_H_ - -#include <limits> - -#include "base/logging.h" - -namespace base { -namespace internal { - -template <bool SameSize, bool DestLarger, - bool DestIsSigned, bool SourceIsSigned> -struct IsValidNumericCastImpl; - -#define BASE_NUMERIC_CAST_CASE_SPECIALIZATION(A, B, C, D, Code) \ -template <> struct IsValidNumericCastImpl<A, B, C, D> { \ - template <class Source, class DestBounds> static inline bool Test( \ - Source source, DestBounds min, DestBounds max) { \ - return Code; \ - } \ -} - -#define BASE_NUMERIC_CAST_CASE_SAME_SIZE(DestSigned, SourceSigned, Code) \ - BASE_NUMERIC_CAST_CASE_SPECIALIZATION( \ - true, true, DestSigned, SourceSigned, Code); \ - BASE_NUMERIC_CAST_CASE_SPECIALIZATION( \ - true, false, DestSigned, SourceSigned, Code) - -#define BASE_NUMERIC_CAST_CASE_SOURCE_LARGER(DestSigned, SourceSigned, Code) \ - BASE_NUMERIC_CAST_CASE_SPECIALIZATION( \ - false, false, DestSigned, SourceSigned, Code); \ - -#define BASE_NUMERIC_CAST_CASE_DEST_LARGER(DestSigned, SourceSigned, Code) \ - BASE_NUMERIC_CAST_CASE_SPECIALIZATION( \ - false, true, DestSigned, SourceSigned, Code); \ - -// The three top level cases are: -// - Same size -// - Source larger -// - Dest larger -// And for each of those three cases, we handle the 4 different possibilities -// of signed and unsigned. This gives 12 cases to handle, which we enumerate -// below. -// -// The last argument in each of the macros is the actual comparison code. It -// has three arguments available, source (the value), and min/max which are -// the ranges of the destination. - - -// These are the cases where both types have the same size. - -// Both signed. -BASE_NUMERIC_CAST_CASE_SAME_SIZE(true, true, true); -// Both unsigned. -BASE_NUMERIC_CAST_CASE_SAME_SIZE(false, false, true); -// Dest unsigned, Source signed. -BASE_NUMERIC_CAST_CASE_SAME_SIZE(false, true, source >= 0); -// Dest signed, Source unsigned. -// This cast is OK because Dest's max must be less than Source's. -BASE_NUMERIC_CAST_CASE_SAME_SIZE(true, false, - source <= static_cast<Source>(max)); - - -// These are the cases where Source is larger. - -// Both unsigned. -BASE_NUMERIC_CAST_CASE_SOURCE_LARGER(false, false, source <= max); -// Both signed. -BASE_NUMERIC_CAST_CASE_SOURCE_LARGER(true, true, - source >= min && source <= max); -// Dest is unsigned, Source is signed. -BASE_NUMERIC_CAST_CASE_SOURCE_LARGER(false, true, - source >= 0 && source <= max); -// Dest is signed, Source is unsigned. -// This cast is OK because Dest's max must be less than Source's. -BASE_NUMERIC_CAST_CASE_SOURCE_LARGER(true, false, - source <= static_cast<Source>(max)); - - -// These are the cases where Dest is larger. - -// Both unsigned. -BASE_NUMERIC_CAST_CASE_DEST_LARGER(false, false, true); -// Both signed. -BASE_NUMERIC_CAST_CASE_DEST_LARGER(true, true, true); -// Dest is unsigned, Source is signed. -BASE_NUMERIC_CAST_CASE_DEST_LARGER(false, true, source >= 0); -// Dest is signed, Source is unsigned. -BASE_NUMERIC_CAST_CASE_DEST_LARGER(true, false, true); - -#undef BASE_NUMERIC_CAST_CASE_SPECIALIZATION -#undef BASE_NUMERIC_CAST_CASE_SAME_SIZE -#undef BASE_NUMERIC_CAST_CASE_SOURCE_LARGER -#undef BASE_NUMERIC_CAST_CASE_DEST_LARGER - - -// The main test for whether the conversion will under or overflow. -template <class Dest, class Source> -inline bool IsValidNumericCast(Source source) { - typedef std::numeric_limits<Source> SourceLimits; - typedef std::numeric_limits<Dest> DestLimits; - COMPILE_ASSERT(SourceLimits::is_specialized, argument_must_be_numeric); - COMPILE_ASSERT(SourceLimits::is_integer, argument_must_be_integral); - COMPILE_ASSERT(DestLimits::is_specialized, result_must_be_numeric); - COMPILE_ASSERT(DestLimits::is_integer, result_must_be_integral); - - return IsValidNumericCastImpl< - sizeof(Dest) == sizeof(Source), - (sizeof(Dest) > sizeof(Source)), - DestLimits::is_signed, - SourceLimits::is_signed>::Test( - source, - DestLimits::min(), - DestLimits::max()); -} - -} // namespace internal - -// checked_numeric_cast<> is analogous to static_cast<> for numeric types, -// except that it CHECKs that the specified numeric conversion will not -// overflow or underflow. Floating point arguments are not currently allowed -// (this is COMPILE_ASSERTd), though this could be supported if necessary. -template <class Dest, class Source> -inline Dest checked_numeric_cast(Source source) { - CHECK(internal::IsValidNumericCast<Dest>(source)); - return static_cast<Dest>(source); -} - -} // namespace base - -#endif // BASE_SAFE_NUMERICS_H_ |