[lldb/crashlog] Add --no-parallel-image-loading hidden flag

[medismailben]

This patch adds the --no-parallel-image-loading to the crashlog command. By default, image loading will happen in parallel in the crashlog script however, sometimes, when running tests or debugging the crashlog script itself, it's better to load the images sequentially.

As its name suggests, this flag will disable the default image loading behaviour to load all the images sequencially in the main thread.

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Med Ismail Bennani (medismailben)

Changes

This patch adds the --no-parallel-image-loading to the crashlog command. By default, image loading will happen in parallel in the crashlog script however, sometimes, when running tests or debugging the crashlog script itself, it's better to load the images sequentially.

As its name suggests, this flag will disable the default image loading behaviour to load all the images sequencially in the main thread.

---

Full diff: https://github.com/llvm/llvm-project/pull/94513.diff

2 Files Affected:

• (modified) lldb/examples/python/crashlog.py (+38-16)
• (modified) lldb/examples/python/crashlog_scripted_process.py (+7)

diff --git a/lldb/examples/python/crashlog.py b/lldb/examples/python/crashlog.py
index 641b2e64d53b1..485e60ab95bba 100755
--- a/lldb/examples/python/crashlog.py
+++ b/lldb/examples/python/crashlog.py
@@ -555,30 +555,44 @@ def load_images(self, options, loaded_images=None):
 
         futures = []
         with tempfile.TemporaryDirectory() as obj_dir:
-            with concurrent.futures.ThreadPoolExecutor() as executor:
 
-                def add_module(image, target, obj_dir):
-                    return image, image.add_module(target, obj_dir)
+            def add_module(image, target, obj_dir):
+                return image, image.add_module(target, obj_dir)
+
+            if options.parallel_image_loading:
+                with concurrent.futures.ThreadPoolExecutor() as executor:
+                    for image in images_to_load:
+                        if image not in loaded_images:
+                            if image.uuid == uuid.UUID(int=0):
+                                continue
+                            futures.append(
+                                executor.submit(
+                                    add_module,
+                                    image=image,
+                                    target=self.target,
+                                    obj_dir=obj_dir,
+                                )
+                            )
 
+                    for future in concurrent.futures.as_completed(futures):
+                        image, err = future.result()
+                        if err:
+                            print(err)
+                        else:
+                            loaded_images.append(image)
+            else:
                 for image in images_to_load:
                     if image not in loaded_images:
                         if image.uuid == uuid.UUID(int=0):
                             continue
-                        futures.append(
-                            executor.submit(
-                                add_module,
-                                image=image,
-                                target=self.target,
-                                obj_dir=obj_dir,
-                            )
+                        image, err = add_module(
+                            image=image, target=self.target, obj_dir=obj_dir
                         )
 
-                for future in concurrent.futures.as_completed(futures):
-                    image, err = future.result()
-                    if err:
-                        print(err)
-                    else:
-                        loaded_images.append(image)
+                        if err:
+                            print(err)
+                        else:
+                            loaded_images.append(image)
 
 
 class CrashLogFormatException(Exception):
@@ -1528,6 +1542,7 @@ def load_crashlog_in_scripted_process(debugger, crashlog_path, options, result):
                 "file_path": crashlog_path,
                 "load_all_images": options.load_all_images,
                 "crashed_only": options.crashed_only,
+                "parallel_image_loading": options.parallel_image_loading,
             }
         )
     )
@@ -1720,6 +1735,13 @@ def CreateSymbolicateCrashLogOptions(
         help="show source for all threads, not just the crashed thread",
         default=False,
     )
+    arg_parser.add_argument(
+        "--no-parallel-image-loading",
+        dest="parallel_image_loading",
+        action="store_false",
+        help=argparse.SUPPRESS,
+        default=True,
+    )
     if add_interactive_options:
         arg_parser.add_argument(
             "-i",
diff --git a/lldb/examples/python/crashlog_scripted_process.py b/lldb/examples/python/crashlog_scripted_process.py
index 26c5c37b7371d..ebce4834ef198 100644
--- a/lldb/examples/python/crashlog_scripted_process.py
+++ b/lldb/examples/python/crashlog_scripted_process.py
@@ -84,6 +84,13 @@ def __init__(self, exe_ctx: lldb.SBExecutionContext, args: lldb.SBStructuredData
             if crashed_only.GetType() == lldb.eStructuredDataTypeBoolean:
                 self.options.crashed_only = crashed_only.GetBooleanValue()
 
+        parallel_image_loading = args.GetValueForKey("parallel_image_loading")
+        if parallel_image_loading and parallel_image_loading.IsValid():
+            if parallel_image_loading.GetType() == lldb.eStructuredDataTypeBoolean:
+                self.options.parallel_image_loading = (
+                    parallel_image_loading.GetBooleanValue()
+                )
+
         self.pid = super().get_process_id()
         self.crashed_thread_idx = 0
         self.exception = None