This commit adjusts the pretty printer for `std::coroutine_handle` based on recent personal experiences with debugging C++20 coroutines: 1. It adds the `coro_frame` member. This member exposes the complete coroutine frame contents, including the suspension point id and all internal variables which the compiler decided to persist into the coroutine frame. While this data is highly compiler-specific, inspecting it can help identify the internal state of suspended coroutines. 2. It includes the `promise` and `coro_frame` members, even if devirtualization failed and we could not infer the promise type / the coro_frame type. Having them available as `void*` pointers can still be useful to identify, e.g., which two coroutine handles have the same frame / promise pointers.
The problem was in calling GetLoadAddress on a value in the error state, where `ValueObject::GetLoadAddress` could end up accessing the uninitialized "address type" by-ref return value from `GetAddressOf`. This probably happened because each function expected the other to initialize it. We can guarantee initialization by turning this into a proper return value. I've added a test, but it only (reliably) crashes if lldb is built with ubsan.
Add an overloaded `GetTypeSystem` to specify the expected type system subclass. Changes code from `GetTypeSystem().dyn_cast_or_null<TypeSystemClang>()` to `GetTypeSystem<TypeSystemClang>()`.
This patch replaces the use of `UINT32_MAX` as the error return value of `GetIndexOfChildWithName` with `llvm::Expected`. # Tasks to do in another PR 1. Replace `CalculateNumChildrenIgnoringErrors` with `CalculateNumChildren`. See [this comment](https://github.com/llvm/llvm-project/pull/136693#discussion_r2056319358). 2. Update `lldb_private::formatters::ExtractIndexFromString` to use `llvm::Expected`. See [this comment](https://github.com/llvm/llvm-project/pull/136693#discussion_r2054217536). 3. Create a new class which carries both user and internal errors. See [this comment](https://github.com/llvm/llvm-project/pull/136693#discussion_r2056439608).
The vast majority of `SyntheticChildrenFrontEnd` subclasses provide children, and as such implement `MightHaveChildren` with a constant value of `true`. This change makes `true` the default value. With this change, `MightHaveChildren` only needs to be implemented by synthetic providers that can return `false`, which is only 3 subclasses.
Change GetNumChildren()/CalculateNumChildren() methods return llvm::Expected This is an NFC change that does not yet add any error handling or change any code to return any errors. This is the second big change in the patch series started with https://github.com/llvm/llvm-project/pull/83501 A follow-up PR will wire up error handling.
This reverts commit 99118c809367d518ffe4de60c16da953744b68b9.
Change GetNumChildren()/CalculateNumChildren() methods return llvm::Expected This is an NFC change that does not yet add any error handling or change any code to return any errors. This is the second big change in the patch series started with https://github.com/llvm/llvm-project/pull/83501 A follow-up PR will wire up error handling.