Breakpad processor: Save Windows unwinding data earlier in x86 walker.

At the moment, StackwalkerX86::GetCallerFrame doesn't save the
WindowsFrameInfo that it finds for a frame unless it successfully
constructs the caller frame. This means that the windows_frame_info
field of the last frame on the stack is left unset, even when that
frame does have windows unwinding information.

This is not user-visible behavior, so it doesn't matter, but it is a
blemish on the interface, and unit tests (added in a later patch)
expect it.

This patch saves the information in the frame as soon as we find it.

a=jimblandy, r=mmentovai


git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@508 4c0a9323-5329-0410-9bdc-e9ce6186880e

1 files changed, 4 insertions, 3 deletions

diff --git a/src/processor/stackwalker_x86.cc b/src/processor/stackwalker_x86.cc
index 27fdc09c..747b5e3a 100644
--- a/src/processor/stackwalker_x86.cc
+++ b/src/processor/stackwalker_x86.cc
@@ -103,6 +103,10 @@ StackFrame* StackwalkerX86::GetCallerFrame(const CallStack *stack) {
   WindowsFrameInfo *last_frame_info
       = resolver_->FindWindowsFrameInfo(last_frame);
 
+  // Save the stack walking info we found, in case we need it later to
+  // find the callee of the frame we're constructing now.
+  last_frame->windows_frame_info = last_frame_info;
+
   // This stackwalker sets each frame's %esp to its value immediately prior
   // to the CALL into the callee.  This means that %esp points to the last
   // callee argument pushed onto the stack, which may not be where %esp points
@@ -442,9 +446,6 @@ StackFrame* StackwalkerX86::GetCallerFrame(const CallStack *stack) {
   // StackFrameX86.
   frame->instruction = frame->context.eip - 1;
 
-  // Save the stack walking info we found for the callee.
-  last_frame->windows_frame_info = last_frame_info;
-
   return frame;
 }