Improve ARM CPU info reporting.

This patch improves several things for Linux/ARM:

- Better detection of the number of CPUs on the target
  device. The content of /proc/cpuinfo only matches the
  number of "online" CPUs, which varies over time with
  recent Android devices.

- Reconstruct the CPUID and ELF hwcaps values from
  /proc/cpuinfo, this is useful to better identify
  target devices in minidumps.

- Make minidump_dump display the new information
  in useful ways.

- Write a small helper class to parse /proc/cpuinfo
  and also use it for x86/64.

- Write a small helper class to parse sysfds cpu lists.

- Add a my_memchr() implementation.

- Add unit tests.

Tested on a Nexus S (1 CPU), Galaxy Nexus (2 CPUs)
and a Nexus 4 (4 CPUs).

Review URL: https://breakpad.appspot.com/540003

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1160 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/common/linux/linux_libc_support.cc

@@ -138,6 +138,16 @@ const char* my_strrchr(const char* haystack, char needle) {
   return ret;
 }
 
+void* my_memchr(const void* src, int needle, size_t src_len) {
+  const unsigned char* p = (const unsigned char*)src;
+  const unsigned char* p_end = p + src_len;
+  for (; p < p_end; ++p) {
+    if (*p == needle)
+      return (void*)p;
+  }
+  return NULL;
+}
+
 // Read a hex value
 //   result: (output) the resulting value
 //   s: a string

src/common/linux/linux_libc_support.h

@@ -77,6 +77,8 @@ extern const char* my_read_decimal_ptr(uintptr_t* result, const char* s);
 
 extern void my_memset(void* ip, char c, size_t len);
 
+extern void* my_memchr(const void* src, int c, size_t len);
+
 // The following are considered safe to use in a compromised environment.
 // Besides, this gives the compiler an opportunity to optimize their calls.
 #define my_memcpy  memcpy

src/common/linux/linux_libc_support_unittest.cc

@@ -154,6 +154,18 @@ TEST(LinuxLibcSupportTest, strrchr) {
   ASSERT_EQ(abc3 + 6, my_strrchr(abc3, 'a'));
 }
 
+TEST(LinuxLibcSupportTest, memchr) {
+  ASSERT_EQ(NULL, my_memchr("abc", 'd', 3));
+  ASSERT_EQ(NULL, my_memchr("abcd", 'd', 3));
+  ASSERT_EQ(NULL, my_memchr("a", 'a', 0));
+
+  static const char abc3[] = "abcabcabc";
+  ASSERT_EQ(abc3, my_memchr(abc3, 'a', 3));
+  ASSERT_EQ(abc3, my_memchr(abc3, 'a', 9));
+  ASSERT_EQ(abc3+1, my_memchr(abc3, 'b', 9));
+  ASSERT_EQ(abc3+2, my_memchr(abc3, 'c', 9));
+}
+
 TEST(LinuxLibcSupportTest, read_hex_ptr) {
   uintptr_t result;
   const char* last;

src/common/tests/auto_testfile.h

@@ -0,0 +1,127 @@
+// Copyright (c) 2013, 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.
+
+// Utility class for creating a temporary file for unit tests
+// that is deleted in the destructor. Only supported on Posix systems.
+#ifndef GOOGLE_BREAKPAD_COMMON_TESTS_AUTO_TESTFILE
+#define GOOGLE_BREAKPAD_COMMON_TESTS_AUTO_TESTFILE
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <string>
+
+#include "breakpad_googletest_includes.h"
+#include "common/tests/auto_tempdir.h"
+
+namespace google_breakpad {
+
+#ifdef _WIN32
+#error "This header cannot be used on Windows"
+#else
+
+class AutoTestFile {
+public:
+  // Create a new empty test file.
+  // test_prefix: (input) test-specific prefix, can't be NULL.
+  explicit AutoTestFile(const char* test_prefix) {
+    Init(test_prefix);
+  }
+
+  // Create a new test file, and fill it with initial data from a C string.
+  // The terminating zero is not written.
+  // test_prefix: (input) test-specific prefix, can't be NULL.
+  // text: (input) initial content.
+  AutoTestFile(const char* test_prefix, const char* text) {
+    Init(test_prefix);
+    if (fd_ >= 0)
+      WriteText(text, static_cast<size_t>(strlen(text)));
+  }
+
+  AutoTestFile(const char* test_prefix, const char* text, size_t text_len) {
+    Init(test_prefix);
+    if (fd_ >= 0)
+      WriteText(text, text_len);
+  }
+
+  // Destroy test file on scope exit.
+  ~AutoTestFile() {
+    if (fd_ >= 0) {
+      close(fd_);
+      fd_ = -1;
+    }
+  }
+
+  // Returns true iff the test file could be created properly.
+  // Useful in tests inside EXPECT_TRUE(file.IsOk());
+  bool IsOk() {
+    return fd_ >= 0;
+  }
+
+  // Returns the Posix file descriptor for the test file, or -1
+  // If IsOk() returns false. Note: on Windows, this always returns -1.
+  int GetFd() {
+    return fd_;
+  }
+
+private:
+  void Init(const char* test_prefix) {
+    fd_ = -1;
+    char path_templ[PATH_MAX];
+    int ret = snprintf(path_templ, sizeof(path_templ),
+                      TEMPDIR "/%s-unittest.XXXXXX",
+                      test_prefix);
+    if (ret >= static_cast<int>(sizeof(path_templ)))
+      return;
+
+    fd_ = mkstemp(path_templ);
+    if (fd_ < 0)
+      return;
+
+    unlink(path_templ);
+  }
+
+  void WriteText(const char* text, size_t text_len) {
+    int r = HANDLE_EINTR(write(fd_, text, text_len));
+    if (r != static_cast<int>(text_len)) {
+      close(fd_);
+      fd_ = -1;
+      return;
+    }
+
+    lseek(fd_, 0, SEEK_SET);
+  }
+
+  int fd_;
+};
+
+#endif  // !_WIN32
+
+}  // namespace google_breakpad
+
+#endif  // GOOGLE_BREAKPAD_COMMON_TESTS_AUTO_TESTFILE