Move base/debug_on_start to base/debugger and rename it to be _win since it

only does anything on Windows.

TEST=it compiles
BUG=none
Review URL: http://codereview.chromium.org/5984007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@70362 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 151 insertions, 0 deletions

diff --git a/base/debug/debug_on_start_win.cc b/base/debug/debug_on_start_win.cc
new file mode 100644
index 0000000..b5c1094
--- /dev/null
+++ b/base/debug/debug_on_start_win.cc
@@ -0,0 +1,74 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/debug/debug_on_start_win.h"
+
+#include <windows.h>
+
+#include "base/base_switches.h"
+#include "base/basictypes.h"
+#include "base/debug/debugger.h"
+
+namespace base {
+namespace debug {
+
+// Minimalist implementation to try to find a command line argument. We can use
+// kernel32 exported functions but not the CRT functions because we're too early
+// in the process startup.
+// The code is not that bright and will find things like ---argument or
+// /-/argument.
+// Note: command_line is non-destructively modified.
+bool DebugOnStart::FindArgument(wchar_t* command_line, const char* argument_c) {
+  wchar_t argument[50];
+  for (int i = 0; argument_c[i]; ++i)
+    argument[i] = argument_c[i];
+
+  int argument_len = lstrlen(argument);
+  int command_line_len = lstrlen(command_line);
+  while (command_line_len > argument_len) {
+    wchar_t first_char = command_line[0];
+    wchar_t last_char = command_line[argument_len+1];
+    // Try to find an argument.
+    if ((first_char == L'-' || first_char == L'/') &&
+        (last_char == L' ' || last_char == 0 || last_char == L'=')) {
+      command_line[argument_len+1] = 0;
+      // Skip the - or /
+      if (lstrcmpi(command_line+1, argument) == 0) {
+        // Found it.
+        command_line[argument_len+1] = last_char;
+        return true;
+      }
+      // Fix back.
+      command_line[argument_len+1] = last_char;
+    }
+    // Continue searching.
+    ++command_line;
+    --command_line_len;
+  }
+  return false;
+}
+
+// static
+int __cdecl DebugOnStart::Init() {
+  // Try to find the argument.
+  if (FindArgument(GetCommandLine(), switches::kDebugOnStart)) {
+    // We can do 2 things here:
+    // - Ask for a debugger to attach to us. This involve reading the registry
+    //   key and creating the process.
+    // - Do a int3.
+
+    // It will fails if we run in a sandbox. That is expected.
+    base::debug::SpawnDebuggerOnProcess(GetCurrentProcessId());
+
+    // Wait for a debugger to come take us.
+    base::debug::WaitForDebugger(60, false);
+  } else if (FindArgument(GetCommandLine(), switches::kWaitForDebugger)) {
+    // Wait for a debugger to come take us.
+    base::debug::WaitForDebugger(60, true);
+  }
+  return 0;
+}
+
+}  // namespace debug
+}  // namespace base
diff --git a/base/debug/debug_on_start_win.h b/base/debug/debug_on_start_win.h
new file mode 100644
index 0000000..5a1081d
--- /dev/null
+++ b/base/debug/debug_on_start_win.h
@@ -0,0 +1,77 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Define the necessary code and global data to look for kDebugOnStart command
+// line argument. When the command line argument is detected, it invokes the
+// debugger, if no system-wide debugger is registered, a debug break is done.
+
+#ifndef BASE_DEBUG_DEBUG_ON_START_WIN_H_
+#define BASE_DEBUG_DEBUG_ON_START_WIN_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "build/build_config.h"
+
+// This only works on Windows. It's legal to include on other platforms, but
+// will be a NOP.
+#if defined(OS_WIN)
+
+#ifndef DECLSPEC_SELECTANY
+#define DECLSPEC_SELECTANY  __declspec(selectany)
+#endif
+
+namespace base {
+namespace debug {
+
+// Debug on start functions and data.
+class DebugOnStart {
+ public:
+  // Expected function type in the .CRT$XI* section.
+  // Note: See VC\crt\src\internal.h for reference.
+  typedef int  (__cdecl *PIFV)(void);
+
+  // Looks at the command line for kDebugOnStart argument. If found, it invokes
+  // the debugger, if this fails, it crashes.
+  static int __cdecl Init();
+
+  // Returns true if the 'argument' is present in the 'command_line'. It does
+  // not use the CRT, only Kernel32 functions.
+  static bool FindArgument(wchar_t* command_line, const char* argument);
+};
+
+// Set the function pointer to our function to look for a crash on start. The
+// XIB section is started pretty early in the program initialization so in
+// theory it should be called before any user created global variable
+// initialization code and CRT initialization code.
+// Note: See VC\crt\src\defsects.inc and VC\crt\src\crt0.c for reference.
+#ifdef _WIN64
+
+// "Fix" the segment. On x64, the .CRT segment is merged into the .rdata segment
+// so it contains const data only.
+#pragma const_seg(push, ".CRT$XIB")
+// Declare the pointer so the CRT will find it.
+extern const DebugOnStart::PIFV debug_on_start;
+DECLSPEC_SELECTANY const DebugOnStart::PIFV debug_on_start =
+    &DebugOnStart::Init;
+// Fix back the segment.
+#pragma const_seg(pop)
+
+#else  // _WIN64
+
+// "Fix" the segment. On x86, the .CRT segment is merged into the .data segment
+// so it contains non-const data only.
+#pragma data_seg(push, ".CRT$XIB")
+// Declare the pointer so the CRT will find it.
+DECLSPEC_SELECTANY DebugOnStart::PIFV debug_on_start = &DebugOnStart::Init;
+// Fix back the segment.
+#pragma data_seg(pop)
+
+#endif  // _WIN64
+
+}  // namespace debug
+}  // namespace base
+
+#endif  // defined(OS_WIN)
+
+#endif  // BASE_DEBUG_DEBUG_ON_START_WIN_H_