Add optional parameter to WTFReportBacktrace for stackframe count

Source/wtf/Assertions.cpp

 /*
  * Copyright (C) 2003, 2006, 2007 Apple Inc.  All rights reserved.
  * Copyright (C) 2007-2009 Torch Mobile, Inc.
  * Copyright (C) 2011 University of Szeged. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 231 matching lines @@
         ::GetProcAddress(kernel32, "RtlCaptureStackBackTrace"));
     if (captureStackBackTraceFunc)
         *size = captureStackBackTraceFunc(0, *size, stack, 0);
     else
         *size = 0;
 #else
     *size = 0;
 #endif
 }
 
-void WTFReportBacktrace()
+void WTFReportBacktrace(int framesToShow)
 {
-    static const int framesToShow = 31;
     static const int framesToSkip = 2;
-    void* samples[framesToShow + framesToSkip];
+    // Use alloca to allocate on the stack since this function is used in OOM situations.
+    void** samples = static_cast<void**>(alloca((framesToShow + framesToSkip) * sizeof(void *)));
     int frames = framesToShow + framesToSkip;
 
     WTFGetBacktrace(samples, &frames);
     WTFPrintBacktrace(samples + framesToSkip, frames - framesToSkip);
 }
 
 void WTFPrintBacktrace(void** stack, int size)
 {
     for (int i = 0; i < size; ++i) {
         const char* mangledName = 0;
@@ skipping 109 matching lines @@
 
 void WTFLogAlways(const char* format, ...)
 {
     va_list args;
     va_start(args, format);
     vprintf_stderr_with_trailing_newline(format, args);
     va_end(args);
 }
 
 } // extern "C"