Coverity: Fully initialize the |trace_| member variable.

base/debug/stack_trace_win.cc

 // Copyright (c) 2011 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/debug/stack_trace.h"
 
 #include <windows.h>
 #include <dbghelp.h>
 
 #include <iostream>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/memory/singleton.h"
 #include "base/synchronization/lock.h"
 
 namespace base {
 namespace debug {
 
 namespace {
 
 // SymbolContext is a threadsafe singleton that wraps the DbgHelp Sym* family
 // of functions.  The Sym* family of functions may only be invoked by one
 // thread at a time.  SymbolContext code may access a symbol server over the
 // network while holding the lock for this singleton.  In the case of high
-// latency, this code will adversly affect performance.
+// latency, this code will adversely affect performance.
 //
 // There is also a known issue where this backtrace code can interact
 // badly with breakpad if breakpad is invoked in a separate thread while
 // we are using the Sym* functions.  This is because breakpad does now
 // share a lock with this function.  See this related bug:
 //
 //   http://code.google.com/p/google-breakpad/issues/detail?id=311
 //
 // This is a very unlikely edge case, and the current solution is to
 // just ignore it.
@@ skipping 13 matching lines @@
 
   // For the given trace, attempts to resolve the symbols, and output a trace
   // to the ostream os.  The format for each line of the backtrace is:
   //
   //    <tab>SymbolName[0xAddress+Offset] (FileName:LineNo)
   //
   // This function should only be called if Init() has been called.  We do not
   // LOG(FATAL) here because this code is called might be triggered by a
   // LOG(FATAL) itself.
   void OutputTraceToStream(const void* const* trace,
-                           int count,
+                           size_t count,
                            std::ostream* os) {
     base::AutoLock lock(lock_);
 
     for (size_t i = 0; (i < count) && os->good(); ++i) {
       const int kMaxNameLength = 256;
       DWORD_PTR frame = reinterpret_cast<DWORD_PTR>(trace[i]);
 
       // Code adapted from MSDN example:
       // http://msdn.microsoft.com/en-us/library/ms680578(VS.85).aspx
       ULONG64 buffer[
@@ skipping 17 matching lines @@
       line.SizeOfStruct = sizeof(IMAGEHLP_LINE64);
       BOOL has_line = SymGetLineFromAddr64(GetCurrentProcess(), frame,
                                            &line_displacement, &line);
 
       // Output the backtrace line.
       (*os) << "\t";
       if (has_symbol) {
         (*os) << symbol->Name << " [0x" << trace[i] << "+"
               << sym_displacement << "]";
       } else {
-        // If there is no symbol informtion, add a spacer.
+        // If there is no symbol information, add a spacer.
         (*os) << "(No symbol) [0x" << trace[i] << "]";
       }
       if (has_line) {
         (*os) << " (" << line.FileName << ":" << line.LineNumber << ")";
       }
       (*os) << "\n";
     }
   }
 
  private:
@@ skipping 69 matching lines @@
                      GetCurrentThread(),
                      &stack_frame,
                      exception_pointers->ContextRecord,
                      NULL,
                      &SymFunctionTableAccess64,
                      &SymGetModuleBase64,
                      NULL) &&
          count_ < arraysize(trace_)) {
     trace_[count_++] = reinterpret_cast<void*>(stack_frame.AddrPC.Offset);
   }
+
+  for (size_t i = count_; i < arraysize(trace_); ++i)

[brettw, 2012/07/25 17:37:26]

I'd probably use kMacTrace here instead (since you already have a nice constant
for this).

[James Hawkins, 2012/07/25 18:58:09]

OK.  I actually searched for arraysize to get back to this instance and
discovered that the existing code uses arraysize throughout (instead of
kMacTrace).  Should I change all of the usages of arraysize for |trace_|?

+    trace_[i] = NULL;
 }
 
 void StackTrace::PrintBacktrace() const {
   OutputToStream(&std::cerr);
 }
 
 void StackTrace::OutputToStream(std::ostream* os) const {
   SymbolContext* context = SymbolContext::GetInstance();
   DWORD error = context->init_error();
   if (error != ERROR_SUCCESS) {
     (*os) << "Error initializing symbols (" << error
           << ").  Dumping unresolved backtrace:\n";
     for (int i = 0; (i < count_) && os->good(); ++i) {
       (*os) << "\t" << trace_[i] << "\n";
     }
   } else {
     (*os) << "Backtrace:\n";
     context->OutputTraceToStream(trace_, count_, os);
   }
 }
 
 }  // namespace debug
 }  // namespace base