cl: newPointer

[xushiwei]

No description provided.

[fennoai]

Review: cl: newPointer

This PR implements toType/newPointer type conversion, handles void return types in compileFunc, threads a c gogen.PkgRef through blockCtx, and adds a cl/_mod test module. The structure is clean and the void-return handling reads correctly.

Two blocking correctness issues share a root cause: the c package reference is wired to the wrong import path and the wrong symbol name, which together break Int/UInt type resolution. Details inline.

Non-blocking notes:

• toType (cl/type_and_var.go:66,68) calls ctx.c.Ref(...) per type node; since Int/UInt resolve to the same types.Type for the whole compilation, these could be resolved once at blockCtx construction rather than re-looked-up per occurrence. Optional, low impact.
• newPointer's tyVoid branch (cl/type_and_var.go:43-48) is currently unreachable: toType has no lc.TypeVoid case, so a void* pointee hits panic("todo: toType ...") before newPointer ever sees tyVoid. Expected given the WIP status, but worth flagging as intended functionality that is silently inert.

No security concerns found. This is a compile-time codegen tool consuming trusted headers.

[fennoai]

[P0] Wrong import path breaks c package resolution

This imports github.com/lib/c, but the package is github.com/goplus/lib/c everywhere else — the file's own import at compile.go:27, the test stub cl/_mod/stub.go:3, and cl/_mod/go.mod (require github.com/goplus/lib v0.5.2).

This PkgRef is stored in blockCtx.c and used by toType to resolve Int/UInt, so the mismatched path prevents type resolution from working.

c := p.Import("github.com/goplus/lib/c")

[fennoai]

[P0] Ref("UInt") does not exist; symbol is Uint

github.com/goplus/lib/c v0.5.2 defines the unsigned-int alias as Uint (Uint = uint32 in c/c.go:38), not UInt. ctx.c.Ref("UInt") will fail to resolve the object.

		return ctx.c.Ref("Uint").Type()

The adjacent Ref("Int") on line 66 is correct since Int exists.

[fennoai]

[P3] tyVoid bound to UntypedNil is surprising

tyVoid is bound to types.Typ[types.UntypedNil] and compared in newPointer to emit unsafe.Pointer. This works, but the name suggests a distinct void type rather than the untyped-nil sentinel. A short comment explaining that untyped-nil is used as the void sentinel would prevent future confusion. Minor / WIP, non-blocking.