Add AlignedVector and use it for vector<MEMORY_BASIC_INFORMATION64>

util/win/process_info.h

 // Copyright 2015 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.
 
 #ifndef CRASHPAD_UTIL_WIN_PROCESS_INFO_H_
 #define CRASHPAD_UTIL_WIN_PROCESS_INFO_H_
 
 #include <sys/types.h>
 #include <windows.h>
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "util/misc/initialization_state_dcheck.h"
 #include "util/numeric/checked_range.h"
+#include "util/stdlib/aligned_allocator.h"
 #include "util/win/address_types.h"
 
 namespace crashpad {
 
 //! \brief Gathers information about a process given its `HANDLE`. This consists
 //!     primarily of information stored in the Process Environment Block.
 class ProcessInfo {
  public:
+  //! \brief The return type of MemoryInfo(), for convenience.
+  using MemoryBasicInformation64Vector =
+      AlignedVector<MEMORY_BASIC_INFORMATION64>;
+
   //! \brief Contains information about a module loaded into a process.
   struct Module {
     Module();
     ~Module();
 
     //! \brief The pathname used to load the module from disk.
     std::wstring name;
 
     //! \brief The base address of the loaded DLL.
     WinVMAddress dll_base;
@@ skipping 72 matching lines @@
   void Peb(WinVMAddress* peb_address, WinVMSize* peb_size) const;
 
   //! \brief Retrieves the modules loaded into the target process.
   //!
   //! The modules are enumerated in initialization order as detailed in the
   //!     Process Environment Block. The main executable will always be the
   //!     first element.
   bool Modules(std::vector<Module>* modules) const;
 
   //! \brief Retrieves information about all pages mapped into the process.
-  const std::vector<MEMORY_BASIC_INFORMATION64>& MemoryInfo() const;
+  const MemoryBasicInformation64Vector& MemoryInfo() const;
 
   //! \brief Given a range to be read from the target process, returns a vector
   //!     of ranges, representing the readable portions of the original range.
   //!
   //! \param[in] range The range being identified.
   //!
   //! \return A vector of ranges corresponding to the portion of \a range that
   //!     is readable based on the memory map.
   std::vector<CheckedRange<WinVMAddress, WinVMSize>> GetReadableRanges(
       const CheckedRange<WinVMAddress, WinVMSize>& range) const;
@@ skipping 29 matching lines @@
 
   std::vector<Handle> BuildHandleVector(HANDLE process) const;
 
   pid_t process_id_;
   pid_t inherited_from_process_id_;
   HANDLE process_;
   std::wstring command_line_;
   WinVMAddress peb_address_;
   WinVMSize peb_size_;
   std::vector<Module> modules_;
-  std::vector<MEMORY_BASIC_INFORMATION64> memory_info_;
+
+  // memory_info_ is a MemoryBasicInformation64Vector instead of a
+  // std::vector<MEMORY_BASIC_INFORMATION64> because MEMORY_BASIC_INFORMATION64
+  // is declared with __declspec(align(16)), but std::vector<> does not maintain
+  // this alignment on 32-bit x86. clang-cl (but not MSVC cl) takes advantage of
+  // the presumed alignment and emits SSE instructions that require aligned
+  // storage. clang-cl should relax (unfortunately), but in the mean time, this
+  // provides aligned storage. See https://crbug.com/564691 and
+  // http://llvm.org/PR25779.
+  //
+  // TODO(mark): Remove this workaround when http://llvm.org/PR25779 is fixed
+  // and the fix is present in the clang-cl that compiles this code.
+  MemoryBasicInformation64Vector memory_info_;
 
   // Handles() is logically const, but updates this member on first retrieval.
   // See https://crashpad.chromium.org/bug/9.
   mutable std::vector<Handle> handles_;
 
   bool is_64_bit_;
   bool is_wow64_;
   InitializationStateDcheck initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessInfo);
 };
 
 //! \brief Given a memory map of a process, and a range to be read from the
 //!     target process, returns a vector of ranges, representing the readable
 //!     portions of the original range.
 //!
 //! This is a free function for testing, but prefer
 //! ProcessInfo::GetReadableRanges().
 std::vector<CheckedRange<WinVMAddress, WinVMSize>> GetReadableRangesOfMemoryMap(
     const CheckedRange<WinVMAddress, WinVMSize>& range,
-    const std::vector<MEMORY_BASIC_INFORMATION64>& memory_info);
+    const ProcessInfo::MemoryBasicInformation64Vector& memory_info);
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_UTIL_WIN_PROCESS_INFO_H_