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authorAllan Sandfeld Jensen <allan.jensen@theqtcompany.com>2016-01-25 11:39:07 +0100
committerOswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>2016-01-25 15:20:42 +0000
commit6c91641271e536ffaa88a1dff5127e42ee99a91e (patch)
tree703d9dd49602377ddc90cbf886aad37913f2496b /chromium/base/macros.h
parentb145b7fafd36f0c260d6a768c81fc14e32578099 (diff)
downloadqtwebengine-chromium-6c91641271e536ffaa88a1dff5127e42ee99a91e.tar.gz
BASELINE: Update Chromium to 49.0.2623.23
Also adds missing printing sources. Change-Id: I3726b8f0c7d6751c9fc846096c571fadca7108cd Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Diffstat (limited to 'chromium/base/macros.h')
-rw-r--r--chromium/base/macros.h98
1 files changed, 5 insertions, 93 deletions
diff --git a/chromium/base/macros.h b/chromium/base/macros.h
index c5f503fbc3a..46ee1dadb47 100644
--- a/chromium/base/macros.h
+++ b/chromium/base/macros.h
@@ -11,7 +11,6 @@
#define BASE_MACROS_H_
#include <stddef.h> // For size_t.
-#include <string.h> // For memcpy.
// Put this in the declarations for a class to be uncopyable.
#define DISALLOW_COPY(TypeName) \
@@ -27,13 +26,6 @@
TypeName(const TypeName&); \
void operator=(const TypeName&)
-// An older, deprecated, politically incorrect name for the above.
-// NOTE: The usage of this macro was banned from our code base, but some
-// third_party libraries are yet using it.
-// TODO(tfarina): Figure out how to fix the usage of this macro in the
-// third_party libraries and get rid of it.
-#define DISALLOW_EVIL_CONSTRUCTORS(TypeName) DISALLOW_COPY_AND_ASSIGN(TypeName)
-
// A macro to disallow all the implicit constructors, namely the
// default constructor, copy constructor and operator= functions.
//
@@ -44,10 +36,11 @@
TypeName() = delete; \
DISALLOW_COPY_AND_ASSIGN(TypeName)
-// The arraysize(arr) macro returns the # of elements in an array arr.
-// The expression is a compile-time constant, and therefore can be
-// used in defining new arrays, for example. If you use arraysize on
-// a pointer by mistake, you will get a compile-time error.
+// The arraysize(arr) macro returns the # of elements in an array arr. The
+// expression is a compile-time constant, and therefore can be used in defining
+// new arrays, for example. If you use arraysize on a pointer by mistake, you
+// will get a compile-time error. For the technical details, refer to
+// http://blogs.msdn.com/b/the1/archive/2004/05/07/128242.aspx.
// This template function declaration is used in defining arraysize.
// Note that the function doesn't need an implementation, as we only
@@ -55,87 +48,6 @@
template <typename T, size_t N> char (&ArraySizeHelper(T (&array)[N]))[N];
#define arraysize(array) (sizeof(ArraySizeHelper(array)))
-// The COMPILE_ASSERT macro can be used to verify that a compile time
-// expression is true. For example, you could use it to verify the
-// size of a static array:
-//
-// COMPILE_ASSERT(arraysize(content_type_names) == CONTENT_NUM_TYPES,
-// content_type_names_incorrect_size);
-//
-// or to make sure a struct is smaller than a certain size:
-//
-// COMPILE_ASSERT(sizeof(foo) < 128, foo_too_large);
-//
-// The second argument to the macro is the name of the variable. If
-// the expression is false, most compilers will issue a warning/error
-// containing the name of the variable.
-
-#undef COMPILE_ASSERT
-#define COMPILE_ASSERT(expr, msg) static_assert(expr, #msg)
-
-// bit_cast<Dest,Source> is a template function that implements the
-// equivalent of "*reinterpret_cast<Dest*>(&source)". We need this in
-// very low-level functions like the protobuf library and fast math
-// support.
-//
-// float f = 3.14159265358979;
-// int i = bit_cast<int32>(f);
-// // i = 0x40490fdb
-//
-// The classical address-casting method is:
-//
-// // WRONG
-// float f = 3.14159265358979; // WRONG
-// int i = * reinterpret_cast<int*>(&f); // WRONG
-//
-// The address-casting method actually produces undefined behavior
-// according to ISO C++ specification section 3.10 -15 -. Roughly, this
-// section says: if an object in memory has one type, and a program
-// accesses it with a different type, then the result is undefined
-// behavior for most values of "different type".
-//
-// This is true for any cast syntax, either *(int*)&f or
-// *reinterpret_cast<int*>(&f). And it is particularly true for
-// conversions between integral lvalues and floating-point lvalues.
-//
-// The purpose of 3.10 -15- is to allow optimizing compilers to assume
-// that expressions with different types refer to different memory. gcc
-// 4.0.1 has an optimizer that takes advantage of this. So a
-// non-conforming program quietly produces wildly incorrect output.
-//
-// The problem is not the use of reinterpret_cast. The problem is type
-// punning: holding an object in memory of one type and reading its bits
-// back using a different type.
-//
-// The C++ standard is more subtle and complex than this, but that
-// is the basic idea.
-//
-// Anyways ...
-//
-// bit_cast<> calls memcpy() which is blessed by the standard,
-// especially by the example in section 3.9 . Also, of course,
-// bit_cast<> wraps up the nasty logic in one place.
-//
-// Fortunately memcpy() is very fast. In optimized mode, with a
-// constant size, gcc 2.95.3, gcc 4.0.1, and msvc 7.1 produce inline
-// code with the minimal amount of data movement. On a 32-bit system,
-// memcpy(d,s,4) compiles to one load and one store, and memcpy(d,s,8)
-// compiles to two loads and two stores.
-//
-// I tested this code with gcc 2.95.3, gcc 4.0.1, icc 8.1, and msvc 7.1.
-//
-// WARNING: if Dest or Source is a non-POD type, the result of the memcpy
-// is likely to surprise you.
-
-template <class Dest, class Source>
-inline Dest bit_cast(const Source& source) {
- COMPILE_ASSERT(sizeof(Dest) == sizeof(Source), VerifySizesAreEqual);
-
- Dest dest;
- memcpy(&dest, &source, sizeof(dest));
- return dest;
-}
-
// Used to explicitly mark the return value of a function as unused. If you are
// really sure you don't want to do anything with the return value of a function
// that has been marked WARN_UNUSED_RESULT, wrap it with this. Example: