Elamur Groupantswasi-linker
The groupant beside wasi-host/src/lib.rs in the Mova repository: what the code computes, what it never does, how to go back from its outputs, its invariants, cost and checks.
Facts
Implementation material. A Mova code model describes this code at one source revision: partial models, finite checks and their stated scope. It is not a reviewed general exposition, and its labels are shown as written, never raised.
Components
| component | label | where |
|---|---|---|
| approximant | partial | approximant |
| ast | partial | ../syntax.json |
| cost | symbolic source derived | invariant |
| descriptant | present | descriptant |
| invariant | partial | invariant |
| tests | compile and source review | tests |
Obernants
The typed relations around the forward model: the behaviour complement (what the code never does), the reverse reconstruction (every input compatible with an output) and specialised views.
| id | type | label | where |
|---|---|---|---|
behavior_complement | behavior_complement | partial source derived model | behavior_complement |
reverse_reconstruction | reverse_reconstruction | partial source derived model | reverse_reconstruction |
memory_gate | memory_gate | partial source derived model | memory_gate |
rights_projection | rights_projection | partial source derived model | rights_projection |
renumber_alias | renumber_alias | partial source derived model | renumber_alias |
unsupported_effects | unsupported_effects | partial source derived model | unsupported_effects |
Model text
descriptant
wasi-linker
add_wasi registers46 named functions. Wrappers require memory, increment calls then evaluate helper, return errno. proc_exit increments and traps with status without requiring memory. Socket/link/process-raise unsupported. fd rights intersect metadata; renumber clones source to existing target then clears source.
Epoch 2026-10-31
Prospective review recorded before edits. Source review found late output FAULT effects and weaker-than-capability rights metadata; these are modeled as current behavior rather than silently repaired. Only bounded new test blocks were added; production code remains unchanged. Actual finite results and exact restoration receipts live under $MOVA_DATA/runs/octopus-wave31-wasi-2026-10-31. No full mlab guest, frozen suite, GPU or corpus run. This node retains its scoped observations for future refinement.
approximant
Forward relation
add_wasi registers46 named functions. Wrappers require memory, increment calls then evaluate helper, return errno. proc_exit increments and traps with status without requiring memory. Socket/link/process-raise unsupported. fd rights intersect metadata; renumber clones source to existing target then clears source.
Scope: wasi-linker. State and transitions follow the authoritative source, including partial effects before errors. No executable approximate replacement is attached: categorical errno/effects and module execution lack a useful validated percentage metric; future numerical profiles may only use1/2/5/10% caps after domain/reference evidence.
invariant
Invariant and cost
add_wasi registers46 named functions. Wrappers require memory, increment calls then evaluate helper, return errno. proc_exit increments and traps with status without requiring memory. Socket/link/process-raise unsupported. fd rights intersect metadata; renumber clones source to existing target then clears source.
The invariant is conditional on the admitted transition: With memory present, sock_send cannot succeed or access network; absent memory, normal macro wrapper cannot increment its counter. proc_exit is explicitly excepted.
Cost: O(46) registrations; per-call map O(log distinct names) plus helper cost. Unsupported operations O(1) after memory lookup.
No wall-time gain, universal resource bound or atomic rollback is inferred. External Vfs/wasmi/native-mlab work remains separately charged.
models
Typed model catalog
behavior_complement
Subject: wasi-host/src/lib.rs at SHA-256 91213ce9038107912c2dd707c3a6639a2d723cdfceb02981a166a6853800248e, scope wasi-linker. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: With memory present, sock_send cannot succeed or access network; absent memory, normal macro wrapper cannot increment its counter. proc_exit is explicitly excepted.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
reverse_reconstruction
Subject: wasi-host/src/lib.rs at SHA-256 91213ce9038107912c2dd707c3a6639a2d723cdfceb02981a166a6853800248e, scope wasi-linker. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: Call counters omit memoryless wrapper attempts but count helper errors; equal counts permit many call orderings and arguments. proc_exit status may identify final call but not preceding effects.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
memory_gate
Subject: wasi-host/src/lib.rs at SHA-256 91213ce9038107912c2dd707c3a6639a2d723cdfceb02981a166a6853800248e, scope wasi-linker. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: Even no-memory helpers sched_yield and sock_* return FAULT when memory export missing; proc_exit does not.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
rights_projection
Subject: wasi-host/src/lib.rs at SHA-256 91213ce9038107912c2dd707c3a6639a2d723cdfceb02981a166a6853800248e, scope wasi-linker. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: fd_fdstat_set_rights intersects metadata without updating cached read/write booleans; do not infer capability revocation from fdstat alone.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
renumber_alias
Subject: wasi-host/src/lib.rs at SHA-256 91213ce9038107912c2dd707c3a6639a2d723cdfceb02981a166a6853800248e, scope wasi-linker. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: from==to passes both lookups, writes clone then clears same slot; no identity-law assertion is justified.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
unsupported_effects
Subject: wasi-host/src/lib.rs at SHA-256 91213ce9038107912c2dd707c3a6639a2d723cdfceb02981a166a6853800248e, scope wasi-linker. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: Socket operations return NOTSUP after memory check without network traffic; path_link does not create hard links.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
tests
Checks and limits
Source review and compilation only for this scope; no runtime branch-coverage claim.
Exact names: .
Memory tests bypass linker ABI; tiny empty/unreachable guests exercise engine outcomes only. The CLI test uses isolated import/export/journal fixtures.
Five compiled production/helper-source controls: append offset, virtual clock advance, trap status, CLI export gate and newest-mtime max. Each compiles, fails its selected assertion, restores exact original bytes and passes again. These controls cover their target relations, not every node. No assertion-only mutants. See external source-test-map.json, native-commands.json, verify.rs and numeric/raw receipts in $MOVA_DATA/runs/octopus-wave31-wasi-2026-10-31. The example main and frozen mlab paths are never executed.
This page in Markdown → https://md.groupants.elamur.ai/free/en/mova/wasi-host/src/lib.rs.groupant/wasi-linker.groupant/