Find abi before trying to decode the stack.

The CallStack function prints stacks to the log. Unfortunately, our
stack script defaults to arm, so if the data is actually arm64, we'll
do nothing. Modify the script to parse the input trying to determine
the abi before processing the rest of the lines. At the very least,
we'll be able to correctly choose between arm and arm64.

The only downside, is that, the old method could take dumps from different
abis, but no one I know does this.

Bug: 26569638
Change-Id: I5935b82fe0af1e788b0d3edc535b9f0cbb7d1b28

scripts/stack_core.py

@@ -32,7 +32,6 @@ def ConvertTrace(lines):
 
 class TraceConverter:
   process_info_line = re.compile("(pid: [0-9]+, tid: [0-9]+.*)")
-  abi_line = re.compile("(ABI: \'(.*)\')")
   revision_line = re.compile("(Revision: \'(.*)\')")
   signal_line = re.compile("(signal [0-9]+ \(.*\).*)")
   abort_message_line = re.compile("(Abort message: '.*')")
@@ -52,9 +51,6 @@ class TraceConverter:
   spacing = ""
   apk_info = dict()
 
-  def __init__(self):
-    self.UpdateAbiRegexes()
-
   register_names = {
     "arm": "r0|r1|r2|r3|r4|r5|r6|r7|r8|r9|sl|fp|ip|sp|lr|pc|cpsr",
     "arm64": "x0|x1|x2|x3|x4|x5|x6|x7|x8|x9|x10|x11|x12|x13|x14|x15|x16|x17|x18|x19|x20|x21|x22|x23|x24|x25|x26|x27|x28|x29|x30|sp|pc|pstate",
@@ -175,6 +171,9 @@ class TraceConverter:
   def ConvertTrace(self, lines):
     lines = map(self.CleanLine, lines)
     try:
+      if not symbol.ARCH:
+        symbol.SetAbi(lines)
+      self.UpdateAbiRegexes()
       for line in lines:
         self.ProcessLine(line)
       self.PrintOutput(self.trace_lines, self.value_lines)
@@ -281,13 +280,11 @@ class TraceConverter:
     abort_message_header = self.abort_message_line.search(line)
     thread_header = self.thread_line.search(line)
     register_header = self.register_line.search(line)
-    abi_header = self.abi_line.search(line)
     revision_header = self.revision_line.search(line)
     dalvik_jni_thread_header = self.dalvik_jni_thread_line.search(line)
     dalvik_native_thread_header = self.dalvik_native_thread_line.search(line)
-    if process_header or signal_header or abort_message_header or thread_header or abi_header or \
+    if process_header or signal_header or abort_message_header or thread_header or \
         register_header or dalvik_jni_thread_header or dalvik_native_thread_header or revision_header:
-      ret = True
       if self.trace_lines or self.value_lines:
         self.PrintOutput(self.trace_lines, self.value_lines)
         self.PrintDivider()
@@ -310,11 +307,7 @@ class TraceConverter:
         print dalvik_native_thread_header.group(1)
       if revision_header:
         print revision_header.group(1)
-      if abi_header:
-        print abi_header.group(1)
-        symbol.ARCH = abi_header.group(2)
-        self.UpdateAbiRegexes()
-      return ret
+      return True
     trace_line_dict = self.MatchTraceLine(line)
     if trace_line_dict is not None:
       ret = True
@@ -404,7 +397,10 @@ class TraceConverter:
 class RegisterPatternTests(unittest.TestCase):
   def assert_register_matches(self, abi, example_crash, stupid_pattern):
     tc = TraceConverter()
-    for line in example_crash.split('\n'):
+    lines = example_crash.split('\n')
+    symbol.SetAbi(lines)
+    tc.UpdateAbiRegexes()
+    for line in lines:
       tc.ProcessLine(line)
       is_register = (re.search(stupid_pattern, line) is not None)
       matched = (tc.register_line.search(line) is not None)