Add ScopedForbidReturn and its test

util/mac/process_reader.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 "util/mac/process_reader.h"
 
 #include <AvailabilityMacros.h>
 #include <mach/mach_vm.h>
 #include <mach-o/loader.h>
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/mac/mach_logging.h"
 #include "base/mac/scoped_mach_port.h"
 #include "base/mac/scoped_mach_vm.h"
+#include "util/misc/scoped_forbid_return.h"
 
 namespace {
 
 void MachTimeValueToTimeval(const time_value& mach, timeval* tv) {
   tv->tv_sec = mach.seconds;
   tv->tv_usec = mach.microseconds;
 }
 
 kern_return_t MachVMRegionRecurseDeepest(mach_port_t task,
                                          mach_vm_address_t* address,
@@ skipping 177 matching lines @@
   kern_return_t kr = task_threads(task_, &threads, &thread_count);
   if (kr != KERN_SUCCESS) {
     MACH_LOG(WARNING, kr) << "task_threads";
     return;
   }
 
   // The send rights in the |threads| array won’t have their send rights managed
   // by anything until they’re added to |threads_| by the loop below. Any early
   // return (or exception) that happens between here and the completion of the
   // loop below will leak thread port send rights.
+  ScopedForbidReturn threads_need_owners;
 
   base::mac::ScopedMachVM threads_vm(
       reinterpret_cast<vm_address_t>(threads),
       mach_vm_round_page(thread_count * sizeof(*threads)));
 
   for (size_t index = 0; index < thread_count; ++index) {
     ProcessReaderThread thread;
     thread.port = threads[index];
 
 #if defined(ARCH_CPU_X86_FAMILY)
@@ skipping 99 matching lines @@
     mach_vm_address_t stack_pointer = Is64Bit()
                                           ? thread.thread_context.t64.__rsp
                                           : thread.thread_context.t32.__esp;
 #endif
 
     thread.stack_region_address =
         CalculateStackRegion(stack_pointer, &thread.stack_region_size);
 
     threads_.push_back(thread);
   }
+
+  threads_need_owners.Disarm();
 }
 
 void ProcessReader::InitializeModules() {
   DCHECK(!initialized_modules_);
   DCHECK(modules_.empty());
 
   initialized_modules_ = true;
 
   // TODO(mark): Complete this implementation. The implementation depends on
   // process_types, which cannot land yet because it depends on this file,
@@ skipping 167 matching lines @@
       // The red zone would go lower into another region in memory, but no
       // region was found. Memory can only be captured to an address as low as
       // the base address of the region already found.
       *start_address = *region_base;
     }
   }
 #endif
 }
 
 }  // namespace crashpad