diff --git a/src/common/linux/linux_libc_support.cc b/src/common/linux/linux_libc_support.cc new file mode 100644 index 00000000..9bf5b02e --- /dev/null +++ b/src/common/linux/linux_libc_support.cc @@ -0,0 +1,228 @@ +// Copyright (c) 2012, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +// This source file provides replacements for libc functions that we need. If +// we call the libc functions directly we risk crashing in the dynamic linker +// as it tries to resolve uncached PLT entries. + +#include "src/common/linux/linux_libc_support.h" + +#include + +extern "C" { + +size_t my_strlen(const char* s) { + size_t len = 0; + while (*s++) len++; + return len; +} + +int my_strcmp(const char* a, const char* b) { + for (;;) { + if (*a < *b) + return -1; + else if (*a > *b) + return 1; + else if (*a == 0) + return 0; + a++; + b++; + } +} + +int my_strncmp(const char* a, const char* b, size_t len) { + for (size_t i = 0; i < len; ++i) { + if (*a < *b) + return -1; + else if (*a > *b) + return 1; + else if (*a == 0) + return 0; + a++; + b++; + } + + return 0; +} + +// Parse a non-negative integer. +// result: (output) the resulting non-negative integer +// s: a NUL terminated string +// Return true iff successful. +bool my_strtoui(int* result, const char* s) { + if (*s == 0) + return false; + int r = 0; + for (;; s++) { + if (*s == 0) + break; + const int old_r = r; + r *= 10; + if (*s < '0' || *s > '9') + return false; + r += *s - '0'; + if (r < old_r) + return false; + } + + *result = r; + return true; +} + +// Return the length of the given, non-negative integer when expressed in base +// 10. +unsigned my_int_len(intmax_t i) { + if (!i) + return 1; + + int len = 0; + while (i) { + len++; + i /= 10; + } + + return len; +} + +// Convert a non-negative integer to a string +// output: (output) the resulting string is written here. This buffer must be +// large enough to hold the resulting string. Call |my_int_len| to get the +// required length. +// i: the non-negative integer to serialise. +// i_len: the length of the integer in base 10 (see |my_int_len|). +void my_itos(char* output, intmax_t i, unsigned i_len) { + for (unsigned index = i_len; index; --index, i /= 10) + output[index - 1] = '0' + (i % 10); +} + +const char* my_strchr(const char* haystack, char needle) { + while (*haystack && *haystack != needle) + haystack++; + if (*haystack == needle) + return haystack; + return (const char*) 0; +} + +const char* my_strrchr(const char* haystack, char needle) { + const char* ret = NULL; + while (*haystack) { + if (*haystack == needle) + ret = haystack; + haystack++; + } + return ret; +} + +// Read a hex value +// result: (output) the resulting value +// s: a string +// Returns a pointer to the first invalid charactor. +const char* my_read_hex_ptr(uintptr_t* result, const char* s) { + uintptr_t r = 0; + + for (;; ++s) { + if (*s >= '0' && *s <= '9') { + r <<= 4; + r += *s - '0'; + } else if (*s >= 'a' && *s <= 'f') { + r <<= 4; + r += (*s - 'a') + 10; + } else if (*s >= 'A' && *s <= 'F') { + r <<= 4; + r += (*s - 'A') + 10; + } else { + break; + } + } + + *result = r; + return s; +} + +const char* my_read_decimal_ptr(uintptr_t* result, const char* s) { + uintptr_t r = 0; + + for (;; ++s) { + if (*s >= '0' && *s <= '9') { + r *= 10; + r += *s - '0'; + } else { + break; + } + } + *result = r; + return s; +} + +void my_memset(void* ip, char c, size_t len) { + char* p = (char *) ip; + while (len--) + *p++ = c; +} + +size_t my_strlcpy(char* s1, const char* s2, size_t len) { + size_t pos1 = 0; + size_t pos2 = 0; + + while (s2[pos2] != '\0') { + if (pos1 + 1 < len) { + s1[pos1] = s2[pos2]; + pos1++; + } + pos2++; + } + if (len > 0) + s1[pos1] = '\0'; + + return pos2; +} + +size_t my_strlcat(char* s1, const char* s2, size_t len) { + size_t pos1 = 0; + + while (pos1 < len && s1[pos1] != '\0') + pos1++; + + if (pos1 == len) + return pos1; + + return pos1 + my_strlcpy(s1 + pos1, s2, len - pos1); +} + +int my_isspace(int ch) { + // Matches the C locale. + const char spaces[] = " \t\f\n\r\t\v"; + for (size_t i = 0; i < sizeof(spaces); i++) { + if (ch == spaces[i]) + return 1; + } + return 0; +} + +} // extern "C"