snarkVM can't handle duplicate outputs, or record outputs which were received as inputs. #28603
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I decided to go ahead and disallow tuple expressions with external record inputs. It's goofy but we have to impose some goofy restrictions anyway: for instance we can't apply the conditional |
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Note also that the test nested_record_as_function_io.leo now fails. AFAICT it was testing exactly what doesn't work and we're now disallowing - so I'm inclined to just remove it. |
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| external_record_output { | ||
| args: (ty: impl Display, local_name: impl Display, input_name: impl Display), | ||
| msg: format!("Cannot output input external record `{local_name}: {ty}` (which was received as input {input_name})."), |
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| msg: format!("Cannot output input external record `{local_name}: {ty}` (which was received as input {input_name})."), | |
| msg: format!("Cannot output external record `{local_name}: {ty}` (which was received as input `{input_name}`)."), |
Wow, to my surprise that actually does seem to work! Given the linked issue I assumed it'd fail regardless of whether the input record was external or not, but no, external records can just pass through. So I'll need to revise this PR. |
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Rebase with changes allowing external record inputs to pass through, and loosening restrictions that turned out to be unnecessary, like putting external records in tuples. Commit message has changed too. |
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Should this be moved to a compile test if its expected to fail?
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sorry, meant to delete this test (this stuff now appears as record_and_duplicate_outputs.{leo, out})
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This should pass tests now that the |
which were received as inputs. We can handle duplicate outputs by "cloning", and input record ouputs too, unless they were external records. The following changes were made to support the above: - codegen can "clone" registers (by casting it into a new register) - codegen tracks record inputs and clones them if they are output (since record inputs cannot be output by snarkVM) - codegen clones duplicate outputs - type checking disallows assignment to an external record type, of to tuples which contain such - type checking disallows ternary expressions of external record type, or of tuples which contain such - tests of the above functionality Fixes #28602
We can handle duplicate outputs by "cloning", and input record ouputs too, unless they were external records. The latter case we need to catch.
The following changes were made to support the above:
codegen can "clone" registers (by casting it into a new register)
codegen tracks record inputs and clones them if they are output (since record inputs cannot be output by snarkVM)
codegen clones duplicate outputs
type checking disallows assignment to an external record type
type checking disallows tuple expressions containing an input external record type
type checking disallows ternary expressions of external record type, or of tuples which contain such
type checker track external record inputs and makes sure we don't output them
tests of the above functionality
Fixes #28602