Inline record-field array[0..CONST - 1] fails to parse (const-EXPRESSION bound)

• Type: bug (frontend — parser, inline array-type in a record field)
• Track: A (parser.inc array-type / record-field parsing). Filed from Track B (dns_cache) — hand off, do not fix under B/E.
• Status: done
• Owner: trackA-e-bugs

Symptom

An inline anonymous array field whose subrange high bound is a constant expression (CONST - 1) fails: Expected: ], but got: <ident> (Kind: 1). The same array as a named type alias compiles, and an inline field with a literal bound compiles — so it is specifically the inline-field + const-expr combination. Live at pinned v197 (and by construction at HEAD — parser path).

Repro

program rc;
const N = 8;
type
  TE = record v: Integer; end;
  TC = record slots: array[0..N - 1] of TE; end;   { <-- Expected: ], but got: N }
var c: TC;
begin c.slots[0].v := 5; writeln(c.slots[0].v); end.

Green variants (all verified):

• Named alias: TEArr = array[0..N - 1] of TE; TC = record slots: TEArr; end;
• Literal inline bound: slots: array[0..7] of TE;
• Const-expr in a top-level array-type alias (e.g. TDnsIpv4Array = array[0..DNS_MAX_IPS - 1] of LongWord in dns_wire_core) already works.

So the range parser handles 0..CONST-1 everywhere EXCEPT an inline array type in a record-field position — likely a field-declaration path that parses the low bound + .. then calls a stricter "expect ] or a simple bound" branch instead of the full const-expression parser used by named type decls.

Impact

Low-severity but a real dialect hole (FPC accepts the inline form). Worked around in lib/rtl/dns_cache.pas by naming the slot array (TDnsCacheSlots = array[0..DNS_CACHE_SLOTS - 1] of TDnsCacheEntry) — which is arguably cleaner, so no ugly code was left behind, but the parser should accept the inline form.

Gate

make test + self-host byte-identical; add a .pas regression mirroring the repro (inline const-expr-bound array field reads/writes correctly).

Log

• 2026-07-11 — resolved, commit 2c17de43.