Untyped parameters not accepted in class methods (work in standalone procs)

• Type: bug (parser) — language
• Status: urgent (Track A)
• Owner: — (Track A — compiler/**)
• Opened: 2026-06-24
• Found-by: Classes / TStream ([[feature-own-net-http-lib]]) — TStream.Read(var Buffer; …) / Write(const Buffer; …).

Symptom

An untyped var/const parameter (no type after the name) parses in a standalone procedure but is rejected inside a class method:

procedure Px(var B; n: Integer); begin end;     { OK (standalone) }

type TC = class
  function Rd(var B; n: Integer): Integer;       { ERROR }
end;

→ Expected: :, but got: (Kind: 78) at the method's var B parameter.

Standalone untyped params landed earlier ([[feature-untyped-parameters]]); the method-declaration parameter parser did not get the same path, so it demands a : type after the parameter name.

Impact

Blocks TStream.Read(var Buffer; Count) / Write(const Buffer; Count) and TMemoryStream — i.e. the whole standard stream surface (synapse's heaviest Classes need, 16 uses). Any class method with an untyped buffer parameter is affected.

Fix

Use the same untyped-parameter parsing in method declarations (and their implementation headers) that standalone routines already accept: a var/ const/out parameter name with no following : type is an untyped param; @Param yields its address.

Done when

• The TC.Rd(var B; n) repro compiles and runs.
• TStream/TMemoryStream (Read/Write with untyped buffers) compile — together with [[bug-read-write-reserved-as-method-names]].
• Regression test under make test; self-host fixedpoint byte-identical.

Log

• 2026-06-24 — FIXED (Track A). The class-method-declaration param parser now mirrors the standalone routine path: a var/const/out parameter with no following : type is an untyped by-ref param (placeholder tyPointer, ProcParamUntyped set, address passed; @Param reaches it). Self-injection shifts the untyped flags; overload matching already honored ProcParamUntyped. (Implementation headers parse via ParseSubroutine, which already supported untyped params.) Verified with TStream.Read(var Buffer; …) / Write(const Buffer; …). Regression test/test_stream_methods.pas in make test.