0042 - Restricted Unbounded Arrays
| Status | Under Review |
|---|---|
| Author | |
| Sponsor |
- Planned Version: 202x
- PRs: #634
Introduction
New restrictions imposed on where declarators of arrays of unknown size can be used legally in HLSL.
Motivation
Arrays of unknown size cause a variety of problems within HLSL. When used as parameters they cannot be copied in and out which violates the base calling convention. For resource arrays, passing arrays of unknown size makes resource initialization fragile across call boundaries.
Since the behavior of out of bounds accesses is undefined, losing the array bound information at the source level and in the calling convention is rife with potential pitfalls.
Proposed solution
This proposal suggests limiting declarators of arrays of unknown size to:
- Global declarations of resources.
- Variables where an initializer is provided and the array bound is implied by the initializer.
Detailed design
Full specification language is proposed in #634.