Stop overwriting errno in base::StringPrintf, StringAppendV, and StringToDouble

base/process_util_mac.mm

 // Copyright (c) 2012 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/process_util.h"
 
 #import <Cocoa/Cocoa.h>
 #include <crt_externs.h>
 #include <errno.h>
 #include <mach/mach.h>
@@ skipping 14 matching lines @@
 #include <string>
 
 #include "base/debug/debugger.h"
 #include "base/file_util.h"
 #include "base/hash_tables.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_mach_port.h"
 #include "base/posix/eintr_wrapper.h"
+#include "base/scoped_clear_errno.h"
 #include "base/string_util.h"
 #include "base/sys_info.h"
 #include "third_party/apple_apsl/CFBase.h"
 #include "third_party/apple_apsl/malloc.h"
 
 #if ARCH_CPU_32_BITS
 #include <dlfcn.h>
 #include <mach-o/nlist.h>
 
 #include "base/threading/thread_local.h"
@@ skipping 494 matching lines @@
   // nlist() returns addresses as offsets in the image, not the instruction
   // pointer in memory. Use the known in-memory address of malloc()
   // to compute the offset for malloc_error_break().
   uintptr_t reference_addr = reinterpret_cast<uintptr_t>(&malloc);
   reference_addr -= nl[1].n_value;
   reference_addr += nl[0].n_value;
 
   return reinterpret_cast<malloc_error_break_t>(reference_addr);
 }
 
-// Simple scoper that saves the current value of errno, resets it to 0, and on
-// destruction puts the old value back. This is so that CrMallocErrorBreak can
-// safely test errno free from the effects of other routines.
-class ScopedClearErrno {
- public:
-  ScopedClearErrno() : old_errno_(errno) {
-    errno = 0;
-  }
-  ~ScopedClearErrno() {
-    if (errno == 0)
-      errno = old_errno_;
-  }
-
- private:
-  int old_errno_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScopedClearErrno);
-};
-
 // Combines ThreadLocalBoolean with AutoReset.  It would be convenient
 // to compose ThreadLocalPointer<bool> with base::AutoReset<bool>, but that
 // would require allocating some storage for the bool.
 class ThreadLocalBooleanAutoReset {
  public:
   ThreadLocalBooleanAutoReset(ThreadLocalBoolean* tlb, bool new_value)
       : scoped_tlb_(tlb),
         original_value_(tlb->Get()) {
     scoped_tlb_->Set(new_value);
   }
@@ skipping 764 matching lines @@
   }
 }
 
 }  // namespace
 
 void EnsureProcessTerminated(ProcessHandle process) {
   WaitForChildToDie(process, kWaitBeforeKillSeconds);
 }
 
 }  // namespace base