gdb-v8-support.py: add FindAnywhere helper.

R=jkummerow@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/1157683007

Cr-Commit-Position: refs/heads/master@{#28653}

tools/gdb-v8-support.py

@@ -152,3 +152,26 @@ class V8PrintObject (gdb.Command):
     v = v8_get_value(arg)
     gdb.execute('call __gdb_print_v8_object(%d)' % v)
 V8PrintObject()
+
+
+class FindAnywhere (gdb.Command):
+  """Search memory for the given pattern."""
+  MAPPING_RE = re.compile(r"^\s*\[\d+\]\s+0x([0-9A-Fa-f]+)->0x([0-9A-Fa-f]+)")
+  def __init__ (self):
+    super (FindAnywhere, self).__init__ ("find-anywhere", gdb.COMMAND_DATA)
+  def invoke (self, value, from_tty):
+    for l in gdb.execute("maint info sections", to_string = True).split('\n'):
+      m = FindAnywhere.MAPPING_RE.match(l)
+      if m is None:
+        continue
+      startAddr = m.group(1)
+      endAddr = m.group(2)
+      try:
+        result = gdb.execute(
+            "find 0x%s, 0x%s, %s" % (startAddr, endAddr, value),
+            to_string = True)
+        if result.find("not found") == -1:
+          print result
+      except:
+        pass
+FindAnywhere()