Merge of Breakpad Chrome Linux fork

A=agl, Lei Zhang
R=nealsid, agl



git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@384 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/common/linux/linux_libc_support.h

@@ -0,0 +1,178 @@
+// Copyright (c) 2009, 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 header provides replacements for libc functions that we need. We if
+// call the libc functions directly we risk crashing in the dynamic linker as
+// it tries to resolve uncached PLT entries.
+
+#ifndef CLIENT_LINUX_LINUX_LIBC_SUPPORT_H_
+#define CLIENT_LINUX_LINUX_LIBC_SUPPORT_H_
+
+#include <stdint.h>
+#include <limits.h>
+#include <sys/types.h>
+
+extern "C" {
+
+static inline size_t
+my_strlen(const char* s) {
+  size_t len = 0;
+  while (*s++) len++;
+  return len;
+}
+
+static inline 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++;
+  }
+}
+
+static inline 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.
+static inline 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.
+static inline unsigned
+my_int_len(int 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|).
+static inline void
+my_itos(char* output, int i, unsigned i_len) {
+  for (unsigned index = i_len; index; --index, i /= 10)
+    output[index - 1] = '0' + (i % 10);
+}
+
+static inline const char*
+my_strchr(const char* haystack, char needle) {
+  while (*haystack && *haystack != needle)
+    haystack++;
+  if (*haystack == needle)
+    return haystack;
+  return (const char*) 0;
+}
+
+// Read a hex value
+//   result: (output) the resulting value
+//   s: a string
+// Returns a pointer to the first invalid charactor.
+static inline 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;
+}
+
+static inline void
+my_memset(void* ip, char c, size_t len) {
+  char* p = (char *) ip;
+  while (len--)
+    *p++ = c;
+}
+
+}  // extern "C"
+
+#endif  // CLIENT_LINUX_LINUX_LIBC_SUPPORT_H_