SizeOf intrinsic does not support variable or expression operands

• Type: bug
• Status: backlog
• Track: A (compiler)
• Owner: —
• Opened: 2026-06-26 (discovered during Track D documentation validation)

Symptoms

In standard Object Pascal (FPC/Delphi), the SizeOf intrinsic can be called with either a type name or a variable/expression operand:

var
  i: Integer;
begin
  writeln(SizeOf(Integer)); { Works: size of type }
  writeln(SizeOf(i));       { Works in FPC: size of variable }
end;

In PXX, calling SizeOf on a variable or expression triggers a compilation error:

pascal26:66: error: SizeOf: unknown type ()

Root Cause

In compiler/parser.inc around line 3908, the SizeOf intrinsic is parsed and resolved at parse time to an AN_INT_LIT (integer literal). The implementation explicitly expects a known type name as the operand:

{ ---- SizeOf(TypeName) intrinsic: resolved at parse time to AN_INT_LIT ---- }

It does not support resolving the type of a variable or expression operand to determine its size.

Acceptance

• The SizeOf intrinsic accepts both type names (e.g., SizeOf(Integer)) and variable/expression operands (e.g., SizeOf(myVar)).
• Verified by a test case compiling and running successfully on all targets.

DONE 2026-06-26 (Track A)

parser.inc ParseFactor SizeOf: when the operand is not a known type name, fall back to FindSym — a variable operand resolves to its declared type's size (record-by-value var -> RecSize via Syms[].RecName; scalar/pointer/class-ref -> TypeSize). SizeOf(i)==SizeOf(Integer)==4, SizeOf(r)==SizeOf(TR)==16, etc. Self-host byte-identical. NOTE: covers a bare variable token (the ticket's repro); a multi-token expression operand (SizeOf(a.f), SizeOf(arr[0])) still needs the ParseExpr-type-inference path — file a follow-up if a workload hits it.