Map foreign Arrow C Data Interface struct pointers to void *#27
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estebanzimanyi wants to merge 1 commit into
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Map foreign Arrow C Data Interface struct pointers to void *#27estebanzimanyi wants to merge 1 commit into
estebanzimanyi wants to merge 1 commit into
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The Arrow C Data Interface structs (ArrowSchema, ArrowArray) are forward-declared, layout-less foreign types with no MEOS semantics, so a pointer to one is ABI-identical to void *. Emitting them as void * lets every binding's existing opaque-pointer-family handling wrap them uniformly instead of each generator needing an Arrow-specific case: a permissive generator maps an unrecognised pointer to a raw pointer, while a conservative one skips it. Normalise struct ArrowSchema * / ArrowArray * to void * in the declared and canonical spellings, mirroring the existing _Bool -> bool normalisation. Add a generation-time guard that warns when a forward-declared foreign struct pointer appears in the API but is not listed, so it is classified explicitly rather than diverging silently per binding.
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The Arrow C Data Interface structs (
ArrowSchema,ArrowArray) appear in the MEOS public API only at the FFI boundary. They are forward-declared, layout-less foreign types with no MEOS semantics, so a pointer to one is ABI-identical tovoid *.Currently the extractor emits them verbatim as
struct ArrowSchema */struct ArrowArray *, and the downstream generators diverge: a permissive generator (JMEOS) maps an unrecognised struct pointer to a rawPointerand the Arrow functions bind, while a conservative one (GoMEOS) treats it as an unsupported shape and skips the function. Someos_*_to_arrow/meos_*_from_arrowreach some bindings but not others.This normalises
struct ArrowSchema */struct ArrowArray *tovoid *in both the declared and canonical spellings — mirroring the existing_Bool -> boolnormalisation in the same two spelling helpers — so every binding's existing opaque-pointer-family handling (Pointer,_ffi.CData,unsafe.Pointer,IntPtr,*mut c_void) wraps them uniformly, with no per-generator special case. The idiomatic Arrow bridge stays in each binding's hand-written layer, keyed off the*_to_arrow/*_from_arrowfunction name, as with any other opaque-pointer-family value.It also adds a generation-time guard (
find_unlisted_foreign_structs) that warns when a forward-declared foreign struct pointer appears in the API but is not listed in_EXTERNAL_OPAQUE_STRUCTS, so a future external type is classified explicitly instead of diverging silently per binding. The guard distinguishes foreign structs (only ever elaborated,struct X *) from typedef'd MEOS types (also appear bare,Pose *), so MEOS types are never flagged.Verified with the GoMEOS generator: before,
meos_temporal_to_arrowand siblings emit// TODO unsupported param struct ArrowSchema *; after the normalisation, they generate asfunc MeosTemporalToArrow(temp Temporal, out_schema unsafe.Pointer, out_array unsafe.Pointer) bool.