Make debug_util cross platform, adding BeingDebugged and BreakDebugger. Linux

supported added, and Mac OSX left as a todo for the mac team.


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@785 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 249 insertions, 112 deletions

diff --git a/base/SConscript b/base/SConscript
index 40ae21a..f645697 100644
--- a/base/SConscript
+++ b/base/SConscript
@@ -123,6 +123,7 @@ if env['PLATFORM'] == 'win32':
       'base_paths_win.cc',
       'clipboard_win.cc',
       'condition_variable_win.cc',
+      'debug_util_win.cc',
       'file_util_win.cc',
       'iat_patch.cc',
       'lock_impl_win.cc',
@@ -139,6 +140,7 @@ if env['PLATFORM'] == 'win32':
 if env['PLATFORM'] in ('darwin', 'posix'):
   input_files.extend([
       'condition_variable_posix.cc',
+      'debug_util_posix.cc',
       'lock_impl_posix.cc',
       'shared_memory_posix.cc',
       'thread_local_storage_posix.cc',
diff --git a/base/build/base.vcproj b/base/build/base.vcproj
index 428eb1e..b4a886cb 100644
--- a/base/build/base.vcproj
+++ b/base/build/base.vcproj
@@ -258,6 +258,10 @@
 			>
 		</File>
 		<File
+			RelativePath="..\debug_util_win.cc"
+			>
+		</File>
+		<File
 			RelativePath="..\event_recorder.cc"
 			>
 		</File>
diff --git a/base/debug_util.cc b/base/debug_util.cc
index fb60f5a..1679650 100644
--- a/base/debug_util.cc
+++ b/base/debug_util.cc
@@ -27,106 +27,20 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#include <windows.h>
-
-#include "base/basictypes.h"
 #include "base/debug_util.h"
 
-namespace {
-
-// Minimalist key reader.
-// Note: Does not use the CRT.
-bool RegReadString(HKEY root, const wchar_t* subkey,
-                   const wchar_t* value_name, wchar_t* buffer, int* len) {
-  HKEY key = NULL;
-  DWORD res = RegOpenKeyEx(root, subkey, 0, KEY_READ, &key);
-  if (ERROR_SUCCESS != res || key == NULL)
-    return false;
-
-  DWORD type = 0;
-  DWORD buffer_size = *len * sizeof(wchar_t);
-  // We don't support REG_EXPAND_SZ.
-  res = RegQueryValueEx(key, value_name, NULL, &type,
-                        reinterpret_cast<BYTE*>(buffer), &buffer_size);
-  if (ERROR_SUCCESS == res && buffer_size != 0 && type == REG_SZ) {
-    // Make sure the buffer is NULL terminated.
-    buffer[*len - 1] = 0;
-    *len = lstrlen(buffer);
-    RegCloseKey(key);
-    return true;
-  }
-  RegCloseKey(key);
-  return false;
-}
-
-// Replaces each "%ld" in input per a value. Not efficient but it works.
-// Note: Does not use the CRT.
-bool StringReplace(const wchar_t* input, int value, wchar_t* output,
-                   int output_len) {
-  memset(output, 0, output_len*sizeof(wchar_t));
-  int input_len = lstrlen(input);
-
-  for (int i = 0; i < input_len; ++i) {
-    int current_output_len = lstrlen(output);
-
-    if (input[i] == L'%' && input[i + 1] == L'l' && input[i + 2] == L'd') {
-      // Make sure we have enough place left.
-      if ((current_output_len + 12) >= output_len)
-        return false;
-
-      // Cheap _itow().
-      wsprintf(output+current_output_len, L"%d", value);
-      i += 2;
-    } else {
-      if (current_output_len >= output_len)
-        return false;
-      output[current_output_len] = input[i];
-    }
-  }
-  return true;
-}
-
-}  // namespace
-
-// Note: Does not use the CRT.
-bool DebugUtil::SpawnDebuggerOnProcess(unsigned process_id) {
-  wchar_t reg_value[1026];
-  int len = arraysize(reg_value);
-  if (RegReadString(HKEY_LOCAL_MACHINE,
-      L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\AeDebug",
-      L"Debugger", reg_value, &len)) {
-    wchar_t command_line[1026];
-    if (StringReplace(reg_value, process_id, command_line,
-                      arraysize(command_line))) {
-      // We don't mind if the debugger is present because it will simply fail
-      // to attach to this process.
-      STARTUPINFO startup_info = {0};
-      startup_info.cb = sizeof(startup_info);
-      PROCESS_INFORMATION process_info = {0};
+#include <windows.h>
 
-      if (CreateProcess(NULL, command_line, NULL, NULL, FALSE, 0, NULL, NULL,
-                        &startup_info, &process_info)) {
-        CloseHandle(process_info.hThread);
-        WaitForInputIdle(process_info.hProcess, 10000);
-        CloseHandle(process_info.hProcess);
-        return true;
-      }
-    }
-  }
-  return false;
-}
+#include "base/platform_thread.h"
 
-// Note: Does not use the CRT.
 bool DebugUtil::WaitForDebugger(int wait_seconds, bool silent) {
   for (int i = 0; i < wait_seconds * 10; ++i) {
-    if (IsDebuggerPresent()) {
-      if (!silent) {
-        // If you hit here, you just use -debug-on-start or -debug-children.
-        __debugbreak();
-      }
+    if (BeingDebugged()) {
+      if (!silent)
+        BreakDebugger();
       return true;
     }
-    Sleep(100);
+    PlatformThread::Sleep(100);
   }
   return false;
 }
diff --git a/base/debug_util.h b/base/debug_util.h
index 54381e5..288ea4b 100644
--- a/base/debug_util.h
+++ b/base/debug_util.h
@@ -27,8 +27,12 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef BASE_DEBUG_UTIL_H__
-#define BASE_DEBUG_UTIL_H__
+// This is a cross platform interface for helper functions related to debuggers.
+// You should use this to test if you're running under a debugger, and if you
+// would like to yield (breakpoint) into the debugger.
+
+#ifndef BASE_DEBUG_UTIL_H_
+#define BASE_DEBUG_UTIL_H_
 
 class DebugUtil {
  public:
@@ -39,6 +43,12 @@ class DebugUtil {
   // Waits wait_seconds seconds for a debugger to attach to the current process.
   // When silent is false, an exception is thrown when a debugger is detected.
   static bool WaitForDebugger(int wait_seconds, bool silent);
+
+  // Are we running under a debugger?
+  static bool BeingDebugged();
+
+  // Break into the debugger, assumes a debugger is present.
+  static void BreakDebugger();
 };
 
-#endif  // BASE_DEBUG_UTIL_H__
+#endif  // BASE_DEBUG_UTIL_H_
diff --git a/base/debug_util_posix.cc b/base/debug_util_posix.cc
new file mode 100644
index 0000000..84b5aae
--- /dev/null
+++ b/base/debug_util_posix.cc
@@ -0,0 +1,90 @@
+// Copyright 2008, 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.
+
+#include "base/debug_util.h"
+
+#include <unistd.h>
+#include <sys/sysctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "base/notimplemented.h"
+#include "base/string_piece.h"
+
+bool DebugUtil::SpawnDebuggerOnProcess(unsigned /* process_id */) {
+  NOTIMPLEMENTED();
+  return false;
+}
+
+#if defined(OS_MACOSX)
+// http://developer.apple.com/qa/qa2004/qa1361.html
+bool DebugUtil::BeingDebugged() {
+  NOTIMPLEMENTED();
+  return false;
+}
+
+#elif defined(OS_LINUX)
+// We can look in /proc/self/status for TracerPid.  We are likely used in crash
+// handling, so we are careful not to use the heap or have side effects.
+// Another option that is common is to try to ptrace yourself, but then we
+// can't detach without forking(), and that's not so great.
+bool DebugUtil::BeingDebugged() {
+  int status_fd = open("/proc/self/status", O_RDONLY);
+  if (status_fd == -1)
+    return false;
+
+  // We assume our line will be in the first 1024 characters and that we can
+  // read this much all at once.  In practice this will generally be true.
+  // This simplifies and speeds up things considerably.
+  char buf[1024];
+
+  ssize_t num_read = read(status_fd, buf, sizeof(buf));
+  close(status_fd);
+
+  if (num_read <= 0)
+    return false;
+
+  StringPiece status(buf, num_read);
+  StringPiece tracer("TracerPid:\t");
+
+  StringPiece::size_type pid_index = status.find(tracer);
+  if (pid_index == StringPiece::npos)
+    return false;
+
+  // Our pid is 0 without a debugger, assume this for any pid starting with 0.
+  pid_index += tracer.size();
+  return pid_index < status.size() && status[pid_index] != '0';
+}
+#endif
+
+// static
+void DebugUtil::BreakDebugger() {
+  asm ("int3");
+}
diff --git a/base/debug_util_win.cc b/base/debug_util_win.cc
new file mode 100644
index 0000000..0f67a16
--- /dev/null
+++ b/base/debug_util_win.cc
@@ -0,0 +1,127 @@
+// Copyright 2008, 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.
+
+#include <windows.h>
+
+#include "base/basictypes.h"
+#include "base/debug_util.h"
+
+namespace {
+
+// Minimalist key reader.
+// Note: Does not use the CRT.
+bool RegReadString(HKEY root, const wchar_t* subkey,
+                   const wchar_t* value_name, wchar_t* buffer, int* len) {
+  HKEY key = NULL;
+  DWORD res = RegOpenKeyEx(root, subkey, 0, KEY_READ, &key);
+  if (ERROR_SUCCESS != res || key == NULL)
+    return false;
+
+  DWORD type = 0;
+  DWORD buffer_size = *len * sizeof(wchar_t);
+  // We don't support REG_EXPAND_SZ.
+  res = RegQueryValueEx(key, value_name, NULL, &type,
+                        reinterpret_cast<BYTE*>(buffer), &buffer_size);
+  if (ERROR_SUCCESS == res && buffer_size != 0 && type == REG_SZ) {
+    // Make sure the buffer is NULL terminated.
+    buffer[*len - 1] = 0;
+    *len = lstrlen(buffer);
+    RegCloseKey(key);
+    return true;
+  }
+  RegCloseKey(key);
+  return false;
+}
+
+// Replaces each "%ld" in input per a value. Not efficient but it works.
+// Note: Does not use the CRT.
+bool StringReplace(const wchar_t* input, int value, wchar_t* output,
+                   int output_len) {
+  memset(output, 0, output_len*sizeof(wchar_t));
+  int input_len = lstrlen(input);
+
+  for (int i = 0; i < input_len; ++i) {
+    int current_output_len = lstrlen(output);
+
+    if (input[i] == L'%' && input[i + 1] == L'l' && input[i + 2] == L'd') {
+      // Make sure we have enough place left.
+      if ((current_output_len + 12) >= output_len)
+        return false;
+
+      // Cheap _itow().
+      wsprintf(output+current_output_len, L"%d", value);
+      i += 2;
+    } else {
+      if (current_output_len >= output_len)
+        return false;
+      output[current_output_len] = input[i];
+    }
+  }
+  return true;
+}
+
+}  // namespace
+
+// Note: Does not use the CRT.
+bool DebugUtil::SpawnDebuggerOnProcess(unsigned process_id) {
+  wchar_t reg_value[1026];
+  int len = arraysize(reg_value);
+  if (RegReadString(HKEY_LOCAL_MACHINE,
+      L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\AeDebug",
+      L"Debugger", reg_value, &len)) {
+    wchar_t command_line[1026];
+    if (StringReplace(reg_value, process_id, command_line,
+                      arraysize(command_line))) {
+      // We don't mind if the debugger is present because it will simply fail
+      // to attach to this process.
+      STARTUPINFO startup_info = {0};
+      startup_info.cb = sizeof(startup_info);
+      PROCESS_INFORMATION process_info = {0};
+
+      if (CreateProcess(NULL, command_line, NULL, NULL, FALSE, 0, NULL, NULL,
+                        &startup_info, &process_info)) {
+        CloseHandle(process_info.hThread);
+        WaitForInputIdle(process_info.hProcess, 10000);
+        CloseHandle(process_info.hProcess);
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
+// static
+bool DebugUtil::BeingDebugged() {
+  return ::IsDebuggerPresent() != 0;
+}
+
+// static
+void DebugUtil::BreakDebugger() {
+  __debugbreak();
+}
diff --git a/base/logging.cc b/base/logging.cc
index 2648346..1e20dd0 100644
--- a/base/logging.cc
+++ b/base/logging.cc
@@ -59,6 +59,7 @@ typedef pthread_mutex_t* MutexHandle;
 #include <algorithm>
 #include "base/base_switches.h"
 #include "base/command_line.h"
+#include "base/debug_util.h"
 #include "base/lock_impl.h"
 #include "base/logging.h"
 #include "base/string_util.h"
@@ -473,13 +474,9 @@ LogMessage::~LogMessage() {
 
   if (severity_ == LOG_FATAL) {
     // display a message or break into the debugger on a fatal error
-#if defined(OS_WIN)
-    if (::IsDebuggerPresent()) {
-      __debugbreak();
-    } 
-    else
-#endif
-    {
+    if (DebugUtil::BeingDebugged()) {
+      DebugUtil::BreakDebugger();
+    } else {
       if (log_assert_handler) {
         // make a copy of the string for the handler out of paranoia
         log_assert_handler(std::string(stream_.str()));
@@ -488,16 +485,9 @@ LogMessage::~LogMessage() {
         // the debug message process
         DisplayDebugMessage(stream_.str());
         // Crash the process to generate a dump.
-#if defined(OS_WIN)
-        __debugbreak();
-#elif defined(OS_POSIX)
-#if defined(OS_MACOSX)
-        // TODO: when we have breakpad support, generate a breakpad dump, but
-        // until then, do not invoke the Apple crash reporter.
-        Debugger();
-#endif
-        exit(-1);
-#endif
+        DebugUtil::BreakDebugger();
+        // TODO(mmentovai): when we have breakpad support, generate a breakpad
+        // dump, but until then, do not invoke the Apple crash reporter.
       }
     }
   }