[lldb/crashlog] Add support for Last Exception Backtrace

[mib]

Summary

This patch adds support to the "Last Exception Backtrace" to the
crashlog command.

This metadata is homologous to the "Application Specific Backtrace",
however the format is closer to a regular stack frame.

Since the thread that "contains" the "Last Exception Backtrace" doesn't
really exist, this information is displayed when requesting an extended
backtrace of the crashed thread, similarly to the "Application Specific
Backtrace".

To achieve that, this patch includes some refactors and fixes to the
existing "Application Specific Backtrace" handling.

rdar://113046509

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

[bulbazord]

lldb/examples/python/crashlog.py

799–815

Conceptually it looks like this is creating a new thread and adding it over and over to the crashlog list of threads? How does this work?

[mib]

lldb/examples/python/crashlog.py

799–815

Indeed, this is bogus :p Good catch!

[JDevlieghere]

LGTM with Alex' comment.

lldb/examples/python/crashlog.py

class JSONCrashLogParser(CrashLogParser):
     def parse(self):
         try:
             self.parse_process_info(self.data)
             self.parse_images(self.data["usedImages"])
             self.parse_main_image(self.data)
             self.parse_threads(self.data["threads"])
             if "asi" in self.data:
                 self.crashlog.asi = self.data["asi"]
+            # FIXME: With the current design, we can either show the ASI or Last
+            # Exception Backtrace, not both. Is there a situation where we would
+            # like to show both ?
             if "asiBacktraces" in self.data:
                 self.parse_app_specific_backtraces(self.data["asiBacktraces"])
             if "lastExceptionBacktrace" in self.data:
-                self.crashlog.asb = self.data["lastExceptionBacktrace"]
+                self.parse_last_exception_backtraces(
+                    self.data["lastExceptionBacktrace"]
+                )
             self.parse_errors(self.data)
             thread = self.crashlog.threads[self.crashlog.crashed_thread_idx]
             reason = self.parse_crash_reason(self.data["exception"])
             if thread.reason:
                 thread.reason = "{} {}".format(thread.reason, reason)
             else:
                 thread.reason = reason
         except (KeyError, ValueError, TypeError) as e:
def parse_asi_backtrace(self, thread, bt):
                         }
 
             thread.frames.append(
                 self.crashlog.Frame(int(frame_id), int(frame_addr, 0), description)
             )
 
         return True
 
     def parse_app_specific_backtraces(self, json_app_specific_bts):
-        for idx, backtrace in enumerate(json_app_specific_bts):
-            thread = self.crashlog.Thread(idx, True, self.crashlog.process_arch)
-            thread.queue = "Application Specific Backtrace"
-            if self.parse_asi_backtrace(thread, backtrace):
-                self.crashlog.threads.append(thread)
+        thread = self.crashlog.Thread(
+            len(self.crashlog.threads), True, self.crashlog.process_arch
+        )
+        if self.parse_asi_backtrace(thread, json_app_specific_bts[0]):
+            self.crashlog.threads.append(thread)
+        else:
+            print("error: Couldn't parse Application Specific Backtrace.")
+
+    def parse_last_exception_backtraces(self, json_last_exc_bts):
+        thread = self.crashlog.Thread(
+            len(self.crashlog.threads), True, self.crashlog.process_arch
+        )
+        thread.queue = "Last Exception Backtrace"
+        self.parse_frames(thread, json_last_exc_bts)
 
     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":

lldb/examples/python/scripted_process/crashlog_scripted_process.py

class CrashLogScriptedThread(ScriptedThread):
 
     def __init__(self, process, args, crashlog_thread):
         super().__init__(process, args)
 
         self.backing_thread = crashlog_thread
         self.idx = self.backing_thread.index
         self.tid = self.backing_thread.id
         if self.backing_thread.app_specific_backtrace:
-            self.name = "Application Specific Backtrace - " + str(self.idx)
+            self.name = "Application Specific Backtrace"
         else:
             self.name = self.backing_thread.name
         self.queue = self.backing_thread.queue
         self.has_crashed = self.scripted_process.crashed_thread_idx == self.idx
         self.create_stackframes()
 
     def get_state(self):
         if not self.has_crashed:

lldb/test/Shell/ScriptInterpreter/Python/Crashlog/Inputs/application_specific_info/asi.txt

   "responsibleProc" : "Terminal",
   "wakeTime" : 1351,
   "sleepWakeUUID" : "AD23E0A0-A4A5-4B6B-925F-2FC3665C17BF",
   "sip" : "enabled",
   "exception" : {"codes":"0x0000000000000000, 0x0000000000000000","rawCodes":[0,0],"type":"EXC_CRASH","signal":"SIGABRT"},
   "asi" : {"CoreFoundation":["*** Terminating app due to uncaught exception 'NSRangeException', reason: '*** __boundsFail: index 10 beyond bounds [0 .. 3]'"],"libsystem_c.dylib":["abort() called"],"libc++abi.dylib":["terminating with uncaught exception of type NSException"]},
   "asiBacktraces" : ["0   CoreFoundation                      0x00000001a0a58418 __exceptionPreprocess + 176\n1   libobjc.A.dylib                     0x00000001a05a2ea8 objc_exception_throw + 60\n2   CoreFoundation                      0x00000001a0b3dcc4 -[__NSCFString characterAtIndex:].cold.1 + 0\n3   CoreFoundation                      0x00000001a0b46af4 -[__NSArrayI getObjects:range:].cold.1 + 0\n4   CoreFoundation                      0x00000001a09a12a4 __CFPropertyListIsArrayPlistAux + 0\n5   asi                                 0x00000001047e3ed0 main + 128\n6   dyld                                0x00000001a05d3e50 start + 2544"],
   "extMods" : {"caller":{"thread_create":0,"thread_set_state":0,"task_for_pid":0},"system":{"thread_create":0,"thread_set_state":4,"task_for_pid":4},"targeted":{"thread_create":0,"thread_set_state":0,"task_for_pid":0},"warnings":0},
-  "lastExceptionBacktrace" : [{"imageOffset":1033228,"symbol":"__exceptionPreprocess","symbolLocation":164,"imageIndex":5},{"imageOffset":110248,"symbol":"objc_exception_throw","symbolLocation":60,"imageIndex":4},{"imageOffset":1973444,"symbol":"-[__NSCFString characterAtIndex:].cold.1","symbolLocation":0,"imageIndex":5},{"imageOffset":2009844,"symbol":"-[__NSArrayI getObjects:range:].cold.1","symbolLocation":0,"imageIndex":5},{"imageOffset":283300,"symbol":"__CFPropertyListIsArrayPlistAux","symbolLocation":0,"imageIndex":5},{"imageOffset":16080,"symbol":"main","symbolLocation":128,"imageIndex":6},{"imageOffset":24144,"symbol":"start","symbolLocation":2544,"imageIndex":7}],
   "faultingThread" : 0,
   "threads" : [{"triggered":true,"id":1767667,"threadState":{"x":[{"value":0},{"value":0},{"value":0},{"value":0},{"value":6988476661},{"value":6096540848},{"value":110},{"value":512},{"value":502518818286880576},{"value":502518810403597248},{"value":512},{"value":11},{"value":11},{"value":2095104},{"value":2043},{"value":2195963912},{"value":328},{"value":8604857144},{"value":0},{"value":6},{"value":8522738816,"symbolLocation":0,"symbol":"_main_thread"},{"value":259},{"value":8522739040,"symbolLocation":224,"symbol":"_main_thread"},{"value":105553117118464},{"value":8528036928,"symbolLocation":0,"symbol":"gProcessInfo"},{"value":0},{"value":0},{"value":0},{"value":0}],"flavor":"ARM_THREAD_STATE64","lr":{"value":6988750060},"cpsr":{"value":1073745920},"fp":{"value":6096540704},"sp":{"value":6096540672},"esr":{"value":1442840704,"description":" Address size fault"},"pc":{"value":6988526116,"matchesCrashFrame":1},"far":{"value":5452680264}},"queue":"com.apple.main-thread","frames":[{"imageOffset":37412,"symbol":"__pthread_kill","symbolLocation":8,"imageIndex":0},{"imageOffset":27884,"symbol":"pthread_kill","symbolLocation":288,"imageIndex":1},{"imageOffset":496328,"symbol":"abort","symbolLocation":180,"imageIndex":2},{"imageOffset":72472,"symbol":"abort_message","symbolLocation":132,"imageIndex":3},{"imageOffset":6668,"symbol":"demangling_terminate_handler()","symbolLocation":336,"imageIndex":3},{"imageOffset":145252,"symbol":"_objc_terminate()","symbolLocation":144,"imageIndex":4},{"imageOffset":69300,"symbol":"std::__terminate(void (*)())","symbolLocation":20,"imageIndex":3},{"imageOffset":80940,"symbol":"__cxxabiv1::failed_throw(__cxxabiv1::__cxa_exception*)","symbolLocation":36,"imageIndex":3},{"imageOffset":80856,"symbol":"__cxa_throw","symbolLocation":140,"imageIndex":3},{"imageOffset":110600,"symbol":"objc_exception_throw","symbolLocation":412,"imageIndex":4},{"imageOffset":1973444,"symbol":"_CFThrowFormattedException","symbolLocation":108,"imageIndex":5},{"imageOffset":2009844,"symbol":"__boundsFail","symbolLocation":92,"imageIndex":5},{"imageOffset":283300,"symbol":"-[__NSArrayI objectAtIndex:]","symbolLocation":60,"imageIndex":5},{"imageOffset":16080,"symbol":"main","symbolLocation":128,"imageIndex":6},{"imageOffset":24144,"symbol":"start","symbolLocation":2544,"imageIndex":7}]}],
   "usedImages" : [
   {
     "source" : "P",
     "arch" : "arm64e",
     "base" : 6988488704,
     "size" : 233468,

lldb/test/Shell/ScriptInterpreter/Python/Crashlog/last_exception_backtrace_crashlog.test

+# REQUIRES: python, native && target-aarch64 && system-darwin
+
+# RUN: mkdir -p %t.dir
+# RUN: yaml2obj %S/Inputs/application_specific_info/asi.yaml > %t.dir/asi
+# RUN: %lldb -o 'command script import lldb.macosx.crashlog' \
+# RUN: -o 'crashlog -a -i -t %t.dir/asi %S/Inputs/application_specific_info/leb.txt' \
+# RUN: -o "thread list" -o "bt all" 2>&1 | FileCheck %s
+
+# CHECK: "crashlog" {{.*}} commands have been installed, use the "--help" options on these commands
+
+# CHECK: (lldb) process status --verbose
+# CHECK-NEXT: Process 96535 stopped
+# CHECK-NEXT: * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_CRASH (code=0, subcode=0x0)
+# CHECK-NEXT:     frame #0: 0x00000001a08c7224{{.*}}[artificial]
+# CHECK: Extended Crash Information:
+# CHECK:   Application Specific Information:
+# CHECK-NEXT:     CoreFoundation: *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** __boundsFail: index 10 beyond bounds [0 .. 3]'
+# CHECK-NEXT:     libc++abi.dylib: terminating with uncaught exception of type NSException
+# CHECK-NEXT:     libsystem_c.dylib: abort() called
+
+
+# CHECK: (lldb) thread backtrace --extended true
+# CHECK: * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_CRASH (code=0, subcode=0x0)
+# CHECK-NEXT:   * frame #0: 0x00000001a08c7224{{.*}}[artificial]
+# CHECK-NEXT:     frame #1: 0x00000001a08fdceb{{.*}}[artificial]
+# CHECK-NEXT:     frame #2: 0x00000001a08372c7{{.*}}[artificial]
+# CHECK-NEXT:     frame #3: 0x00000001a08b7b17{{.*}}[artificial]
+# CHECK-NEXT:     frame #4: 0x00000001a08a7a0b{{.*}}[artificial]
+# CHECK-NEXT:     frame #5: 0x00000001a05ab763{{.*}}[artificial]
+# CHECK-NEXT:     frame #6: 0x00000001a08b6eb3{{.*}}[artificial]
+# CHECK-NEXT:     frame #7: 0x00000001a08b9c2b{{.*}}[artificial]
+# CHECK-NEXT:     frame #8: 0x00000001a08b9bd7{{.*}}[artificial]
+# CHECK-NEXT:     frame #9: 0x00000001a05a3007{{.*}}[artificial]
+# CHECK-NEXT:     frame #10: 0x00000001a0b3dcc3{{.*}}[artificial]
+# CHECK-NEXT:     frame #11: 0x00000001a0b46af3{{.*}}[artificial]
+# CHECK-NEXT:     frame #12: 0x00000001a09a12a3{{.*}}[artificial]
+# CHECK-NEXT:     frame #13: 0x00000001047e3ecf asi`main{{.*}}[artificial]
+# CHECK-NEXT:     frame #14: 0x00000001a05d3e4f{{.*}}[artificial]
+
+# CHECK:   thread #4294967295: tid = 0x0001, 0x00000001a0a5840c{{.*}}, queue = 'Application Specific Backtrace'
+# CHECK-NEXT:     frame #0: 0x00000001a0a5840c{{.*}}
+# CHECK-NEXT:     frame #1: 0x00000001a05a2ea7{{.*}}
+# CHECK-NEXT:     frame #2: 0x00000001a0b3dcc3{{.*}}
+# CHECK-NEXT:     frame #3: 0x00000001a0b46af3{{.*}}
+# CHECK-NEXT:     frame #4: 0x00000001a09a12a3{{.*}}
+# CHECK-NEXT:     frame #5: 0x00000001047e3ecf asi`main{{.*}}
+# CHECK-NEXT:     frame #6: 0x00000001a05d3e4f
+
+
+# CHECK: (lldb) thread list
+# CHECK-NEXT: Process 96535 stopped
+# CHECK-NEXT: * thread #1: tid = 0x1af8f3, 0x00000001a08c7224{{.*}}, queue = 'com.apple.main-thread', stop reason = EXC_CRASH (code=0, subcode=0x0)