Add most of ProcessReader and its test

util/mac/process_reader.h

Index: util/mac/process_reader.h
diff --git a/util/mac/process_reader.h b/util/mac/process_reader.h
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+// 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.
+
+#ifndef CRASHPAD_UTIL_MAC_PROCESS_READER_H_
+#define CRASHPAD_UTIL_MAC_PROCESS_READER_H_
+
+#include <mach/mach.h>
+#include <sys/sysctl.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <time.h>
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "build/build_config.h"
+#include "util/mach/task_memory.h"
+#include "util/misc/initialization_state_dcheck.h"
+
+namespace crashpad {
+
+//! \brief Contains information about a thread that belongs to a task (process).
+struct ProcessReaderThread {
+#if defined(ARCH_CPU_X86_FAMILY)
+  union ThreadContext {
+    x86_thread_state64_t t64;
+    x86_thread_state32_t t32;
+  };
+  union FloatContext {
+    x86_float_state64_t f64;
+    x86_float_state32_t f32;
+  };
+  union DebugContext {
+    x86_debug_state64_t d64;
+    x86_debug_state32_t d32;
+  };
+#endif
+
+  ProcessReaderThread();
+  ~ProcessReaderThread() {}
+
+  ThreadContext thread_context;
+  FloatContext float_context;
+  DebugContext debug_context;
+  uint64_t id;
+  mach_vm_address_t stack_region_address;
+  mach_vm_size_t stack_region_size;
+  mach_vm_address_t thread_specific_data_address;
+  mach_port_t port;
+  int suspend_count;
+  int priority;
+};
+
+//! \brief Contains information about a module loaded into a process.
+struct ProcessReaderModule {
+  ProcessReaderModule();
+  ~ProcessReaderModule();
+
+  std::string name;
+  mach_vm_address_t address;
+  time_t timestamp;
+};
+
+//! \brief Accesses information about another process, identified by a Mach
+//!     task.
+class ProcessReader {
+ public:
+  ProcessReader();
+  ~ProcessReader();
+
+  //! \brief Initializes this object. This method must be called before any
+  //!     other.
+  //!
+  //! \param[in] task A send right to the target task’s task port. This object
+  //!     does not take ownership of the send right.
+  //!
+  //! \return `true` on success, indicating that this object will respond
+  //!     validly to further method calls. `false` on failure. On failure, no
+  //!     further method calls should be made.
+  bool Initialize(mach_port_t task);
+
+  //! \return `true` if the target task is a 64-bit process.
+  bool Is64Bit() const { return is_64_bit_; }
+
+  //! \return The target task’s process ID.
+  pid_t ProcessID() const { return kern_proc_info_.kp_proc.p_pid; }
+
+  //! \return The target task’s parent process ID.
+  pid_t ParentProcessID() const { return kern_proc_info_.kp_eproc.e_ppid; }
+
+  //! \param[out] start_time The time that the process started.
+  void StartTime(timeval* start_time) const;
+
+  //! \param[out] user_time The amount of time the process has executed code in
+  //!     user mode.
+  //! \param[out] system_time The amount of time the process has executed code
+  //!     in system mode.
+  //!
+  //! \return `true` on success, `false` on failure, with a warning logged. On
+  //!     failure, \a user_time and \a system_time will be set to represent no
+  //!     time spent executing code in user or system mode.
+  bool CPUTimes(timeval* user_time, timeval* system_time) const;
+
+  //! \return Accesses the memory of the target task.
+  TaskMemory* Memory() { return task_memory_.get(); }
+
+  //! \return The threads that are in the task (process).
+  const std::vector<ProcessReaderThread>& Threads();
+
+  //! \return The modules loaded in the process.
+  const std::vector<ProcessReaderModule>& Modules();
+
+ private:
+  //! Performs lazy initialization of the \a threads_ vector on behalf of
+  //! Threads().
+  void InitializeThreads();
+
+  //! Performs lazy initialization of the \a modules_ vector on behalf of
+  //! Modules().
+  void InitializeModules();
+
+  //! \brief Calculates the base address and size of the region used as a
+  //!     thread’s stack.
+  //!
+  //! The region returned by this method may be formed by merging multiple
+  //! adjacent regions in a process’ memory map if appropriate. The base address
+  //! of the returned region may be lower than the \a stack_pointer passed in
+  //! when the ABI mandates a red zone below the stack pointer.
+  //!
+  //! \param[in] stack_pointer The stack pointer, referring to the top (lowest
+  //!     address) of a thread’s stack.
+  //! \param[out] stack_region_size The size of the memory region used as the
+  //!     thread’s stack.
+  //!
+  //! \return The base address (lowest address) of the memory region used as the
+  //!     thread’s stack.
+  mach_vm_address_t CalculateStackRegion(mach_vm_address_t stack_pointer,
+                                         mach_vm_size_t* stack_region_size);
+
+  //! \brief Adjusts the region for the red zone, if the ABI requires one.
+  //!
+  //! This method performs red zone calculation for CalculateStackRegion(). Its
+  //! parameters are local variables used within that method, and may be
+  //! modified as needed.
+  //!
+  //! Where a red zone is required, the region of memory captured for a thread’s
+  //! stack will be extended to include the red zone below the stack pointer,
+  //! provided that such memory is mapped, readable, and has the correct user
+  //! tag value. If these conditions cannot be met fully, as much of the red
+  //! zone will be captured as is possible while meeting these conditions.
+  //!
+  //! \param[inout] start_address The base address of the region to begin
+  //!     capturing stack memory from. On entry, \a start_address is the stack
+  //!     pointer. On return, \a start_address may be decreased to encompass a
+  //!     red zone.
+  //! \param[inout] region_base The base address of the region that contains
+  //!     stack memory. This is distinct from \a start_address in that \a
+  //!     region_base will be page-aligned. On entry, \a region_base is the
+  //!     base address of a region that contains \a start_address. On return,
+  //!     if \a start_address is decremented and is outside of the region
+  //!     originally described by \a region_base, \a region_base will also be
+  //!     decremented appropriately.
+  //! \param[inout] region_size The size of the region that contains stack
+  //!     memory. This region begins at \a region_base. On return, if \a
+  //!     region_base is decremented, \a region_size will be incremented
+  //!     appropriately.
+  //! \param[in] user_tag The Mach VM system’s user tag for the region described
+  //!     by the initial values of \a region_base and \a region_size. The red
+  //!     zone will only be allowed to extend out of the region described by
+  //!     these initial values if the user tag is appropriate for stack memory
+  //!     and the expanded region has the same user tag value.
+  void LocateRedZone(mach_vm_address_t* start_address,
+                     mach_vm_address_t* region_base,
+                     mach_vm_address_t* region_size,
+                     unsigned int user_tag);
+
+  kinfo_proc kern_proc_info_;
+  std::vector<ProcessReaderThread> threads_;  // owns send rights
+  std::vector<ProcessReaderModule> modules_;
+  scoped_ptr<TaskMemory> task_memory_;
+  mach_port_t task_;  // weak
+  InitializationStateDcheck initialized_;
+
+  // This shadows a bit in kern_proc_info_, but it’s accessed so frequently that
+  // it’s given a first-class field to save a few bit operations on each access.
+  bool is_64_bit_;
+
+  bool initialized_threads_;
+  bool initialized_modules_;
+
+  DISALLOW_COPY_AND_ASSIGN(ProcessReader);
+};
+
+}  // namespace crashpad
+
+#endif  // CRASHPAD_UTIL_MAC_PROCESS_READER_H_