Cherry-pick the patch preserving dynamic values in result variables #11987
+431 −59
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
…ions (llvm#168611) When you run an expression and the result has a dynamic type that is different from the expression's static result type, we print the result variable using the dynamic type, but at present when you use the result variable in an expression later on, we only give you access to the static type. For instance: ``` (lldb) expr MakeADerivedReportABase() (Derived *) $0 = 0x00000001007e93e0 (lldb) expr $0->method_from_derived() ^ error: no member named 'method_from_derived' in 'Base' (lldb) ``` The static return type of that function is `Base *`, but we printed that the result was a `Derived *` and then only used the `Base *` part of it in subsequent expressions. That's not very helpful, and forces you to guess and then cast the result types to their dynamic type in order to be able to access the full type you were returned, which is inconvenient. This patch makes lldb retain the dynamic type of the result variable (and ditto for persistent result variables). It also adds more testing of expression result variables with various types of dynamic values, to ensure we can access both the ivars and methods of the type we print the result as. (cherry picked from commit 6344e3a)
…lvm#171922) This is a follow-on to: llvm#168611 which added a bunch of tests for detecting dynamic types of C++ result variables. I don't actually know how well dynamic type detection works on Windows if at all. It would require Windows support, since the Linux/Darwin version is specific to the Itanium ABI. (cherry picked from commit 2f14fb3)
Author
| @swift-ci please test |
adrian-prantl approved these changes Dec 12, 2025
Author
| Huh, supposedly all the checks failed but the links to tell me why are all 404... |
Author
| @swift-ci please test |
Author
| I didn't get failures when running these tests locally. Gotta figure out why they are failing on the bots. |
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit. This suggestion is invalid because no changes were made to the code. Suggestions cannot be applied while the pull request is closed. Suggestions cannot be applied while viewing a subset of changes. Only one suggestion per line can be applied in a batch. Add this suggestion to a batch that can be applied as a single commit. Applying suggestions on deleted lines is not supported. You must change the existing code in this line in order to create a valid suggestion. Outdated suggestions cannot be applied. This suggestion has been applied or marked resolved. Suggestions cannot be applied from pending reviews. Suggestions cannot be applied on multi-line comments. Suggestions cannot be applied while the pull request is queued to merge. Suggestion cannot be applied right now. Please check back later.
Also add a test for swift expression result & persistent values (the patch had C++ tests already.)