[llvm-branch-commits] [lldb] 024b86e - If the address of the isa_pointer is returned as an error don't ask if it is a tagged pointer (#213163)

[Tobias Hieta via llvm-branch-commits]

Author: jimingham
Date: 2026-08-27T09:51:30+02:00
New Revision: 024b86e934512fbbd0ad398d461fbe4fcb4fb17b

URL: https://github.com/llvm/llvm-project/commit/024b86e934512fbbd0ad398d461fbe4fcb4fb17b
DIFF: https://github.com/llvm/llvm-project/commit/024b86e934512fbbd0ad398d461fbe4fcb4fb17b.diff

LOG: If the address of the isa_pointer is returned as an error don't ask if it is a tagged pointer (#213163)

The answer isn't right and the wrong type might stick and cause
downstream failures.

Note, the correct solution to this is to distinguish between "couldn't
get the address" and "got a real value of LLDB_INVALID_ADDRESS" but
piping an optional all the way down and then through all the uses is an
intrusive change which I don't have time for right now. That only risk
is that this really IS a tagged pointer with the value
LLDB_INVALID_ADDRESS, so this seems an acceptable workaround.

I ran across this when debugging the ObjC test failures in the ObjC
testuite after 8b9cce358bef26ae4cb9275dd6a43f903bafbaa0. This patch
clears up all those testsuite failures, which should stand as a test for
this patch when I resubmit that change.

(cherry picked from commit 8fbdc8cd027176fb54c5fbcd7688fe78eed0154f)

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
index f1f71f7d7a451..ead9c28ed7058 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
@@ -1646,6 +1646,8 @@ AppleObjCRuntimeV2::GetClassDescriptorImpl(ValueObject &valobj,
   if (!valobj.GetCompilerType().IsValid())
     return objc_class_sp;
   addr_t isa_pointer = valobj.GetPointerValue().address;
+  if (isa_pointer == LLDB_INVALID_ADDRESS)
+    return objc_class_sp;
 
   // tagged pointer
   if (IsTaggedPointer(isa_pointer))