microsoft / microsoft/DirectXShaderCompiler
[SPIR-V] SPV_EXT_descriptor_heap Heap buffer alias function-argument error path returns nullptr for void-returning callees
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- Dominant language
- C++
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Description
Description
In processCall (SpirvEmitter.cpp), when a heap buffer alias is passed to a user function, emitError is called and a getUndef(retTy) placeholder is returned for non-void callees. However, for void-returning callees retTy->isVoidType() causes an early return nullptr, despite a comment in the same block warning this causes an access violation before the diagnostic surfaces.
Fix
For the void-returning case, return a benign non-void undef placeholder (e.g., spvBuilder.getUndef(astContext.IntTy)) rather than nullptr so no null propagates downstream.
References
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start in SpirvEmitter.cpp at processCall and trace the heap buffer alias error path for void-returning callees. Verify the existing diagnostic path does not propagate a null value, then run the relevant SPIR-V compiler tests or regression coverage; done means the diagnostic still surfaces without an access violation.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- cpp
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 2/5
- Estimated time
- 1-3 hours
- Activity status
- Active
- Clarity
- Clearly specified
- Newbie friendliness
- 86/100