[lldb/crashlog] Fix arm64 register parsing on crashlog.py

[mib]

Summary

This patch fixes the register parser for arm64 crashlogs.

Compared to x86_64 crashlogs, the arm64 crashlogs nests the general
purpose registers into a separate dictionary within thread_state
dictionary. It uses the dictionary key as the the register number.

Signed-off-by: Med Ismail Bennani <[e-mail]>

[JDevlieghere]

I recently modified this function to support parsing the rosetta registers. To do that I call parse_thread_registers recursively, and I think we should do the same here and add an optional argument for the prefix. So the result would look something like:

def parse_thread_registers(self, json_thread_state, prefix=None):
    registers = dict()
    for key, state in json_thread_state.items():
        if key == "rosetta":
           registers.update(self.parse_thread_registers(state))
           continue
        if key == "x":
           registers.update(self.parse_thread_registers(state), prefix="x")
           continue
        try:
           value = int(state['value'])
           registers["{}{}".format(prefix,key)] = value
        except (KeyError, ValueError, TypeError):
           pass
    return registers

[mib]

Use the same approach as rosetta.

[shafik]

lldb/examples/python/crashlog.py

529

nitpick: Is there a better way to format this code or rewrite it so that is reads better?

[mib]

lldb/examples/python/crashlog.py

529

@shafik I didn't feel like creating a variable on top of that but if you think it can improve readability, I can do that.

[mib]

Address @shafik comment.

[JDevlieghere]

LGTM

lldb/examples/python/crashlog.py

def parse_threads(self, json_threads):
                 if 'threadState' in json_thread:
                     thread.registers = self.parse_thread_registers(
                         json_thread['threadState'])
             thread.queue = json_thread.get('queue')
             self.parse_frames(thread, json_thread.get('frames', []))
             self.crashlog.threads.append(thread)
             idx += 1
 
-    def parse_thread_registers(self, json_thread_state):
+    def parse_thread_registers(self, json_thread_state, prefix=None):
         registers = dict()
         for key, state in json_thread_state.items():
             if key == "rosetta":
                 registers.update(self.parse_thread_registers(state))
                 continue
+            if key == "x":
+                registers.update(self.parse_thread_registers({ str(idx) : reg
+                                                              for idx,reg in
+                                                              enumerate(state)},
+                                                             prefix=key))
+                continue
             try:
                 value = int(state['value'])
-               registers[key] = value
+                registers["{}{}".format(prefix,key)] = value
             except (KeyError, ValueError, TypeError):
                 pass
         return registers
 
     def parse_errors(self, json_data):
        if 'reportNotes' in json_data:
           self.crashlog.errors = json_data['reportNotes']
 
 
 class CrashLogParseMode: