ppc stackwalker (#30). r=bryner

- Implementation of PowerPC stackwalker.  Tested using stackwalker_selftest
   (#18).
 - Hook up processor-side multi-CPU support in MinidumpProcessor and
   minidump_stackwalk using the new Stackwalker::StackwalkerForCPU method.

http://groups.google.com/group/airbag-dev/browse_thread/thread/1c2fa7c5182a77a9


git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@34 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/processor/stackwalker_ppc.h

@@ -0,0 +1,80 @@
+// Copyright (c) 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// stackwalker_ppc.h: ppc-specific stackwalker.
+//
+// Provides stack frames given ppc register context and a memory region
+// corresponding to a ppc stack.
+//
+// Author: Mark Mentovai
+
+
+#ifndef PROCESSOR_STACKWALKER_PPC_H__
+#define PROCESSOR_STACKWALKER_PPC_H__
+
+
+#include "google/airbag_types.h"
+#include "processor/stackwalker.h"
+#include "processor/minidump_format.h"
+
+namespace google_airbag {
+
+class MinidumpContext;
+class MinidumpModuleList;
+
+
+class StackwalkerPPC : public Stackwalker {
+ public:
+  // context is a MinidumpContext object that gives access to ppc-specific
+  // register state corresponding to the innermost called frame to be
+  // included in the stack.  The other arguments are passed directly through
+  // to the base Stackwalker constructor.
+  StackwalkerPPC(const MDRawContextPPC *context,
+                 MemoryRegion *memory,
+                 MinidumpModuleList *modules,
+                 SymbolSupplier *supplier);
+
+ private:
+  // Implementation of Stackwalker, using ppc context (stack pointer in %r1,
+  // saved program counter in %srr0) and stack conventions (saved stack
+  // pointer at 0(%r1), return address at 8(0(%r1)).
+  virtual bool GetContextFrame(StackFrame *frame);
+  virtual bool GetCallerFrame(StackFrame *frame,
+                              const StackFrames *walked_frames);
+
+  // Stores the CPU context corresponding to the innermost stack frame to
+  // be returned by GetContextFrame.
+  const MDRawContextPPC *context_;
+};
+
+
+} // namespace google_airbag
+
+
+#endif // PROCESSOR_STACKWALKER_PPC_H__