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Diffstat (limited to 'libcutils/strdup16to8.cpp')
| -rw-r--r-- | libcutils/strdup16to8.cpp | 168 |
1 files changed, 0 insertions, 168 deletions
diff --git a/libcutils/strdup16to8.cpp b/libcutils/strdup16to8.cpp deleted file mode 100644 index d89181e14e..0000000000 --- a/libcutils/strdup16to8.cpp +++ /dev/null @@ -1,168 +0,0 @@ -/* libs/cutils/strdup16to8.c -** -** Copyright 2006, The Android Open Source Project -** -** Licensed under the Apache License, Version 2.0 (the "License"); -** you may not use this file except in compliance with the License. -** You may obtain a copy of the License at -** -** http://www.apache.org/licenses/LICENSE-2.0 -** -** Unless required by applicable law or agreed to in writing, software -** distributed under the License is distributed on an "AS IS" BASIS, -** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -** See the License for the specific language governing permissions and -** limitations under the License. -*/ - -#include <cutils/jstring.h> - -#include <assert.h> -#include <limits.h> /* for SIZE_MAX */ -#include <stdlib.h> - - -/** - * Given a UTF-16 string, compute the length of the corresponding UTF-8 - * string in bytes. - */ -extern size_t strnlen16to8(const char16_t* utf16Str, size_t len) -{ - size_t utf8Len = 0; - - /* A small note on integer overflow. The result can - * potentially be as big as 3*len, which will overflow - * for len > SIZE_MAX/3. - * - * Moreover, the result of a strnlen16to8 is typically used - * to allocate a destination buffer to strncpy16to8 which - * requires one more byte to terminate the UTF-8 copy, and - * this is generally done by careless users by incrementing - * the result without checking for integer overflows, e.g.: - * - * dst = malloc(strnlen16to8(utf16,len)+1) - * - * Due to this, the following code will try to detect - * overflows, and never return more than (SIZE_MAX-1) - * when it detects one. A careless user will try to malloc - * SIZE_MAX bytes, which will return NULL which can at least - * be detected appropriately. - * - * As far as I know, this function is only used by strndup16(), - * but better be safe than sorry. - */ - - /* Fast path for the usual case where 3*len is < SIZE_MAX-1. - */ - if (len < (SIZE_MAX-1)/3) { - while (len != 0) { - len--; - unsigned int uic = *utf16Str++; - - if (uic > 0x07ff) - utf8Len += 3; - else if (uic > 0x7f || uic == 0) - utf8Len += 2; - else - utf8Len++; - } - return utf8Len; - } - - /* The slower but paranoid version */ - while (len != 0) { - len--; - unsigned int uic = *utf16Str++; - size_t utf8Cur = utf8Len; - - if (uic > 0x07ff) - utf8Len += 3; - else if (uic > 0x7f || uic == 0) - utf8Len += 2; - else - utf8Len++; - - if (utf8Len < utf8Cur) /* overflow detected */ - return SIZE_MAX-1; - } - - /* don't return SIZE_MAX to avoid common user bug */ - if (utf8Len == SIZE_MAX) - utf8Len = SIZE_MAX-1; - - return utf8Len; -} - - -/** - * Convert a Java-Style UTF-16 string + length to a JNI-Style UTF-8 string. - * - * This basically means: embedded \0's in the UTF-16 string are encoded - * as "0xc0 0x80" - * - * Make sure you allocate "utf8Str" with the result of strlen16to8() + 1, - * not just "len". - * - * Please note, a terminated \0 is always added, so your result will always - * be "strlen16to8() + 1" bytes long. - */ -extern char* strncpy16to8(char* utf8Str, const char16_t* utf16Str, size_t len) -{ - char* utf8cur = utf8Str; - - /* Note on overflows: We assume the user did check the result of - * strnlen16to8() properly or at a minimum checked the result of - * its malloc(SIZE_MAX) in case of overflow. - */ - while (len != 0) { - len--; - unsigned int uic = *utf16Str++; - - if (uic > 0x07ff) { - *utf8cur++ = (uic >> 12) | 0xe0; - *utf8cur++ = ((uic >> 6) & 0x3f) | 0x80; - *utf8cur++ = (uic & 0x3f) | 0x80; - } else if (uic > 0x7f || uic == 0) { - *utf8cur++ = (uic >> 6) | 0xc0; - *utf8cur++ = (uic & 0x3f) | 0x80; - } else { - *utf8cur++ = uic; - - if (uic == 0) { - break; - } - } - } - - *utf8cur = '\0'; - - return utf8Str; -} - -/** - * Convert a UTF-16 string to UTF-8. - * - */ -char * strndup16to8 (const char16_t* s, size_t n) -{ - if (s == NULL) { - return NULL; - } - - size_t len = strnlen16to8(s, n); - - /* We are paranoid, and we check for SIZE_MAX-1 - * too since it is an overflow value for our - * strnlen16to8 implementation. - */ - if (len >= SIZE_MAX-1) - return NULL; - - char* ret = static_cast<char*>(malloc(len + 1)); - if (ret == NULL) - return NULL; - - strncpy16to8 (ret, s, n); - - return ret; -} |
