[Lldb-commits] [PATCH] D128306: [lldb] Instantiate lazily named classes on macOS Ventura.

[Jonas Devlieghere via Phabricator via lldb-commits]

JDevlieghere created this revision.
JDevlieghere added a reviewer: aprantl.
Herald added a project: All.
JDevlieghere requested review of this revision.

Recent revisions of the Objective-C runtime changed
objc_debug_class_getNameRaw() in a way that no longer triggers lazy
names to be instantiated. This has the unintended side-effect of making
generic bridged Swift classes, such as _SwiftDeferredNSDictionary<U,V>
to become invisible to the Objective-C runtime.

This patch detects this situation and forces the names to be
instantiated by calling class_getName() and discarding the result before
calling objc_debug_class_getNameRaw() again.

Many thanks to Mike Ash for outlining the solution and Adrian for
authoring the downstream patch.

rdar://95245318


https://reviews.llvm.org/D128306

Files:
  lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp


Index: lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
===================================================================
--- lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
+++ lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
@@ -205,7 +205,7 @@
         {
             Class isa = realized_class_list[i];
             const char *name_ptr = objc_debug_class_getNameRaw(isa);
-            if (name_ptr == NULL)
+            if (!name_ptr)
                 continue;
             const char *s = name_ptr;
             uint32_t h = 5381;
@@ -239,6 +239,7 @@
     void free(void *ptr);
     size_t objc_getRealizedClassList_trylock(Class *buffer, size_t len);
     const char* objc_debug_class_getNameRaw(Class cls);
+    const char* class_getName(Class cls);
 }
 
 #define DEBUG_PRINTF(fmt, ...) if (should_log) printf(fmt, ## __VA_ARGS__)
@@ -278,7 +279,11 @@
         {
             Class isa = realized_class_list[i];
             const char *name_ptr = objc_debug_class_getNameRaw(isa);
-            if (name_ptr == NULL)
+            if (!name_ptr) {
+               class_getName(isa); // Realize name of lazy classes.
+               name_ptr = objc_debug_class_getNameRaw(isa);
+            }
+            if (!name_ptr)
                 continue;
             const char *s = name_ptr;
             uint32_t h = 5381;


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D128306.438837.patch
Type: text/x-patch
Size: 1426 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/lldb-commits/attachments/20220621/99927600/attachment.bin>