[lldb] Make it easier to spot if sources were resolved in crashlog output

[JDevlieghere]

Summary

It can be tricky to troubleshoot why the crashlog script can't show inline sources. The two most common causes are that we couldn't find the dSYM or, if we find the dSYM, that the path remapping included in the dSYMForUUID output isn't correct. The former is relatively easy to diagnose thanks to the messages printed by the crashlog script. The latter is harder, because you have to figure out the remapped source path. This patch tries to make it easier to diagnose the second issue by including whether the path in the source remapping is accessible. If at least one of the paths exists, we consider the image to have sources, and include that in the symbol resolution output.

Example output:

Resolved symbols and sources for 11111111-2222-3333-4444-555555555555 /path/to/foo
Resolved symbols for 66666666-7777-8888-9999-AAAAAAAAAAAA /path/to/bar

[mib]

lldb/examples/python/crashlog.py

342–345

346

I guess that checks that the user have access to the remapped path, is that right ?

If that's not the case, I think we should let the user know

[JDevlieghere]

lldb/examples/python/crashlog.py

346

Yeah, that's exactly right. We do let the user know by including or emitting "and sources" in the symbol resolution print. Currently we print the "and sources" when at least one of the remapped paths is accessible. We could change this to only print it when all the paths are accessible. We could also change the message the say "and could not find sources" when a path remapping is present but the paths are not accessible.

[mib]

lldb/examples/python/crashlog.py

346

It think it would be clearer for the user if we said something like "couldn't access remapped source path (path/to/source)"

[JDevlieghere]

Make the warning its own line

[mib]

LGTM! Thanks!

lldb/examples/python/crashlog.py

class DarwinImage(symbolication.Image):
             if self.resolved:
                 return True
             # Mark this as resolved so we don't keep trying
             self.resolved = True
             uuid_str = self.get_normalized_uuid_string()
             if self.show_symbol_progress():
                 with print_lock:
                     print("Getting symbols for %s %s..." % (uuid_str, self.path))
+            # Keep track of unresolved source paths.
+            unavailable_source_paths = set()
             if os.path.exists(self.dsymForUUIDBinary):
                 dsym_for_uuid_command = "%s %s" % (self.dsymForUUIDBinary, uuid_str)
                 s = subprocess.check_output(dsym_for_uuid_command, shell=True)
                 if s:
                     try:
                         plist_root = read_plist(s)
                     except:
                         with print_lock:
class DarwinImage(symbolication.Image):
                                 self.arch = plist["DBGArchitecture"]
                             if "DBGDSYMPath" in plist:
                                 self.symfile = os.path.realpath(plist["DBGDSYMPath"])
                             if "DBGSymbolRichExecutable" in plist:
                                 self.path = os.path.expanduser(
                                     plist["DBGSymbolRichExecutable"]
                                 )
                                 self.resolved_path = self.path
+                            if "DBGSourcePathRemapping" in plist:
+                                path_remapping = plist["DBGSourcePathRemapping"]
+                                for _, value in path_remapping.items():
+                                    source_path = os.path.expanduser(value)
+                                    if not os.path.exists(source_path):
+                                        unavailable_source_paths.add(source_path)
             if not self.resolved_path and os.path.exists(self.path):
                 if not self.find_matching_slice():
                     return False
             if not self.resolved_path and not os.path.exists(self.path):
                 try:
                     mdfind_results = (
                         subprocess.check_output(
                             [
                                 "/usr/bin/mdfind",
class DarwinImage(symbolication.Image):
                             break
                 except:
                     pass
             if (self.resolved_path and os.path.exists(self.resolved_path)) or (
                 self.path and os.path.exists(self.path)
             ):
                 with print_lock:
                     print("Resolved symbols for %s %s..." % (uuid_str, self.path))
+                    if len(unavailable_source_paths):
+                        for source_path in unavailable_source_paths:
+                            print(
+                                "Could not access remapped source path for %s %s"
+                                % (uuid_str, source_path)
+                            )
                 return True
             else:
                 self.unavailable = True
             return False
 
     def __init__(self, debugger, path, verbose):
         """CrashLog constructor that take a path to a darwin crash log file"""
         symbolication.Symbolicator.__init__(self, debugger)