win: Get client/crashpad_info.cc to compile

client/crashpad_info.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 #include "client/crashpad_info.h"
 
+#include "util/stdlib/cxx.h"
+
+#if defined(OS_MAC)

[Mark Mentovai, 2014/12/15 23:38:34]

#include "build/build_config.h" to use this.

The correct macro is OS_MACOSX, not OS_MAC. Also below.

[scottmg, 2014/12/16 00:18:07]

Done. I'm unclear on the guidance for this. It must be directly included by this
file or its header? But base/basictypes.h being known to include it is
insufficient?
Oof. Done.

[Mark Mentovai, 2014/12/16 14:14:14]

scottmg wrote:
That’s right. We’re following “include what you use” strictly here.

In Chrome, it’s typically considered OK to rely on build/build_config.h being
available as a side effect of base/basictypes.h being included. In Crashpad, I’m
trying to be more explicit about things.

In fact, in today’s mini_chromium, there’s no reason that base/basictypes.h even
needs to include build/build_config.h at all.

 #include <mach-o/loader.h>
-
-#include "util/stdlib/cxx.h"
+#elif defined(OS_WIN)
+#include <windows.h>
+#endif
 
 #if CXX_LIBRARY_VERSION >= 2011
 #include <type_traits>
 #endif
 
 namespace {
 
 static const uint32_t kCrashpadInfoVersion = 1;
 
 }  // namespace
 
 namespace crashpad {
 
 #if CXX_LIBRARY_VERSION >= 2011 || DOXYGEN
 // In C++11, check that CrashpadInfo has standard layout, which is what is
 // actually important.
 static_assert(std::is_standard_layout<CrashpadInfo>::value,
               "CrashpadInfo must be standard layout");
 #else
 // In C++98 (ISO 14882), section 9.5.1 says that a union cannot have a member
 // with a non-trivial ctor, copy ctor, dtor, or assignment operator. Use this
 // property to ensure that CrashpadInfo remains POD. This doesn’t work for C++11
 // because the requirements for unions have been relaxed.
 union Compile_Assert {
   CrashpadInfo Compile_Assert__CrashpadInfo_must_be_pod;
 };
 #endif
 
+#if defined(OS_MAC)
+
 // Put the structure in __DATA,__crashpad_info where it can be easily found

[Mark Mentovai, 2014/12/15 23:38:34]

Aside from the actual section name, this comment’s not Mac-specific at all, and
doesn’t belong inside the #ifdef.

[scottmg, 2014/12/16 00:18:07]

Improved.

I removed the Windows pragmas for now as without testing them and writing the
thing that reads them they're not much use anyway.

 // without having to consult the symbol table. The “used” attribute prevents it
 // from being dead-stripped. This isn’t placed in an unnamed namespace:
 // hopefully, this will catch attempts to place multiple copies of this
 // structure into the same module. If that’s attempted, and the name of the
 // symbol is the same in each translation unit, it will result in a linker
 // error, which is better than having multiple structures show up.
 //
 // This may result in a static module initializer in debug-mode builds, but
 // because it’s POD, no code should need to run to initialize this under
 // release-mode optimization.
 __attribute__((section(SEG_DATA ",__crashpad_info"),
                used,
                visibility("hidden"))) CrashpadInfo g_crashpad_info;
 
+#elif defined(OS_WIN)
+
+#pragma data_seg(push, crashpad_info, "__crashpad_info")
+CrashpadInfo g_crashpad_info;
+#pragma data_seg(pop, crashpad_info)
+
+#endif
+
 // static
 CrashpadInfo* CrashpadInfo::GetCrashpadInfo() {
   return &g_crashpad_info;
 }
 
 CrashpadInfo::CrashpadInfo()
     : signature_(kSignature),
       size_(sizeof(*this)),
       version_(kCrashpadInfoVersion),
       padding_0_(0),
       simple_annotations_(nullptr) {
 }
 
 const uint32_t CrashpadInfo::kSignature;
 
 }  // namespace crashpad