diff options
Diffstat (limited to 'security/sandbox/chromium/base/strings/string16.h')
| -rw-r--r-- | security/sandbox/chromium/base/strings/string16.h | 187 |
1 files changed, 0 insertions, 187 deletions
diff --git a/security/sandbox/chromium/base/strings/string16.h b/security/sandbox/chromium/base/strings/string16.h deleted file mode 100644 index e47669c1b..000000000 --- a/security/sandbox/chromium/base/strings/string16.h +++ /dev/null @@ -1,187 +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_STRINGS_STRING16_H_ -#define BASE_STRINGS_STRING16_H_ - -// WHAT: -// A version of std::basic_string that provides 2-byte characters even when -// wchar_t is not implemented as a 2-byte type. You can access this class as -// string16. We also define char16, which string16 is based upon. -// -// WHY: -// On Windows, wchar_t is 2 bytes, and it can conveniently handle UTF-16/UCS-2 -// data. Plenty of existing code operates on strings encoded as UTF-16. -// -// On many other platforms, sizeof(wchar_t) is 4 bytes by default. We can make -// it 2 bytes by using the GCC flag -fshort-wchar. But then std::wstring fails -// at run time, because it calls some functions (like wcslen) that come from -// the system's native C library -- which was built with a 4-byte wchar_t! -// It's wasteful to use 4-byte wchar_t strings to carry UTF-16 data, and it's -// entirely improper on those systems where the encoding of wchar_t is defined -// as UTF-32. -// -// Here, we define string16, which is similar to std::wstring but replaces all -// libc functions with custom, 2-byte-char compatible routines. It is capable -// of carrying UTF-16-encoded data. - -#include <stddef.h> -#include <stdint.h> -#include <stdio.h> -#include <string> - -#include "base/base_export.h" -#include "build/build_config.h" - -#if defined(WCHAR_T_IS_UTF16) - -namespace base { - -typedef wchar_t char16; -typedef std::wstring string16; -typedef std::char_traits<wchar_t> string16_char_traits; - -} // namespace base - -#elif defined(WCHAR_T_IS_UTF32) - -namespace base { - -typedef uint16_t char16; - -// char16 versions of the functions required by string16_char_traits; these -// are based on the wide character functions of similar names ("w" or "wcs" -// instead of "c16"). -BASE_EXPORT int c16memcmp(const char16* s1, const char16* s2, size_t n); -BASE_EXPORT size_t c16len(const char16* s); -BASE_EXPORT const char16* c16memchr(const char16* s, char16 c, size_t n); -BASE_EXPORT char16* c16memmove(char16* s1, const char16* s2, size_t n); -BASE_EXPORT char16* c16memcpy(char16* s1, const char16* s2, size_t n); -BASE_EXPORT char16* c16memset(char16* s, char16 c, size_t n); - -struct string16_char_traits { - typedef char16 char_type; - typedef int int_type; - - // int_type needs to be able to hold each possible value of char_type, and in - // addition, the distinct value of eof(). - static_assert(sizeof(int_type) > sizeof(char_type), - "int must be larger than 16 bits wide"); - - typedef std::streamoff off_type; - typedef mbstate_t state_type; - typedef std::fpos<state_type> pos_type; - - static void assign(char_type& c1, const char_type& c2) { - c1 = c2; - } - - static bool eq(const char_type& c1, const char_type& c2) { - return c1 == c2; - } - static bool lt(const char_type& c1, const char_type& c2) { - return c1 < c2; - } - - static int compare(const char_type* s1, const char_type* s2, size_t n) { - return c16memcmp(s1, s2, n); - } - - static size_t length(const char_type* s) { - return c16len(s); - } - - static const char_type* find(const char_type* s, size_t n, - const char_type& a) { - return c16memchr(s, a, n); - } - - static char_type* move(char_type* s1, const char_type* s2, size_t n) { - return c16memmove(s1, s2, n); - } - - static char_type* copy(char_type* s1, const char_type* s2, size_t n) { - return c16memcpy(s1, s2, n); - } - - static char_type* assign(char_type* s, size_t n, char_type a) { - return c16memset(s, a, n); - } - - static int_type not_eof(const int_type& c) { - return eq_int_type(c, eof()) ? 0 : c; - } - - static char_type to_char_type(const int_type& c) { - return char_type(c); - } - - static int_type to_int_type(const char_type& c) { - return int_type(c); - } - - static bool eq_int_type(const int_type& c1, const int_type& c2) { - return c1 == c2; - } - - static int_type eof() { - return static_cast<int_type>(EOF); - } -}; - -typedef std::basic_string<char16, base::string16_char_traits> string16; - -BASE_EXPORT extern std::ostream& operator<<(std::ostream& out, - const string16& str); - -// This is required by googletest to print a readable output on test failures. -BASE_EXPORT extern void PrintTo(const string16& str, std::ostream* out); - -} // namespace base - -// The string class will be explicitly instantiated only once, in string16.cc. -// -// std::basic_string<> in GNU libstdc++ contains a static data member, -// _S_empty_rep_storage, to represent empty strings. When an operation such -// as assignment or destruction is performed on a string, causing its existing -// data member to be invalidated, it must not be freed if this static data -// member is being used. Otherwise, it counts as an attempt to free static -// (and not allocated) data, which is a memory error. -// -// Generally, due to C++ template magic, _S_empty_rep_storage will be marked -// as a coalesced symbol, meaning that the linker will combine multiple -// instances into a single one when generating output. -// -// If a string class is used by multiple shared libraries, a problem occurs. -// Each library will get its own copy of _S_empty_rep_storage. When strings -// are passed across a library boundary for alteration or destruction, memory -// errors will result. GNU libstdc++ contains a configuration option, -// --enable-fully-dynamic-string (_GLIBCXX_FULLY_DYNAMIC_STRING), which -// disables the static data member optimization, but it's a good optimization -// and non-STL code is generally at the mercy of the system's STL -// configuration. Fully-dynamic strings are not the default for GNU libstdc++ -// libstdc++ itself or for the libstdc++ installations on the systems we care -// about, such as Mac OS X and relevant flavors of Linux. -// -// See also http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24196 . -// -// To avoid problems, string classes need to be explicitly instantiated only -// once, in exactly one library. All other string users see it via an "extern" -// declaration. This is precisely how GNU libstdc++ handles -// std::basic_string<char> (string) and std::basic_string<wchar_t> (wstring). -// -// This also works around a Mac OS X linker bug in ld64-85.2.1 (Xcode 3.1.2), -// in which the linker does not fully coalesce symbols when dead code -// stripping is enabled. This bug causes the memory errors described above -// to occur even when a std::basic_string<> does not cross shared library -// boundaries, such as in statically-linked executables. -// -// TODO(mark): File this bug with Apple and update this note with a bug number. - -extern template -class BASE_EXPORT std::basic_string<base::char16, base::string16_char_traits>; - -#endif // WCHAR_T_IS_UTF32 - -#endif // BASE_STRINGS_STRING16_H_ |