Initial implementation of x86 stackwalker (#9). r=bryner

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@12 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/processor/stackwalker.cc

@@ -0,0 +1,78 @@
+// Copyright (C) 2006 Google Inc.
+//
+// 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.
+
+// stackwalker.cc: Generic stackwalker.
+//
+// See stackwalker.h for documentation.
+//
+// Author: Mark Mentovai
+
+
+#include <memory>
+
+#include "processor/stackwalker.h"
+#include "processor/minidump.h"
+
+
+namespace google_airbag {
+
+
+using std::auto_ptr;
+
+
+Stackwalker::Stackwalker(MemoryRegion* memory, MinidumpModuleList* modules)
+    : memory_(memory), modules_(modules) {
+}
+
+
+StackFrames* Stackwalker::Walk() {
+  auto_ptr<StackFrames> frames(new StackFrames());
+
+  // Begin with the context frame, and keep getting callers until there are
+  // no more.
+
+  auto_ptr<StackFrame> frame(new StackFrame());
+  bool valid = GetContextFrame(frame.get());
+  while (valid) {
+    // frame already contains a good frame with properly set instruction and
+    // frame_pointer fields.  The frame structure comes from either the
+    // context frame (above) or a caller frame (below).
+
+    // Resolve the module information, if a module map was provided.
+    if (modules_) {
+      MinidumpModule* module =
+          modules_->GetModuleForAddress(frame->instruction);
+      if (module) {
+        frame->module_name = *(module->GetName());
+        frame->module_base = module->base_address();
+      }
+    }
+
+    // Copy the frame into the frames vector.
+    frames->push_back(*frame);
+
+    // Use a new object for the next frame, even though the old object was
+    // copied.  If StackFrame provided some sort of Clear() method, then
+    // the same frame could be reused.
+    frame.reset(new StackFrame());
+
+    // Get the next frame.
+    valid = GetCallerFrame(frame.get());
+  }
+
+  return frames.release();
+}
+
+
+} // namespace google_airbag