{$R-} / {$R+} range-check toggle misread as a resource directive

• Type: bug (lexer / directive parsing) — blocks at emit
• Status: urgent (Track A)
• Owner: — (Track A — compiler/**)
• Opened: 2026-06-24
• Found-by: [[feature-synapse-compile-check]] — synacode.pas:50 is {$R-}; exposed once synacode started passing semantics (Move/IntToHex/StringOfChar landed), so it now reaches emit.

Symptom

{$R-} and {$R+} are the range-check compiler switches (like {$Q-}, {$I-}). PXX's {$R} handler treats everything after R as a resource filename, so {$R-} registers a pending resource named -, and at emit time:

error: resource file not found or empty: -

Minimal repro:

program p;
{$R-}
begin end.

→ error: resource file not found or empty: - ()

Scope (only {$R} is affected — the sibling toggles disambiguate +/- correctly):

The error surfaces at emit (compiler/resources_emit.inc:52), not lexing, so it was masked until now: any earlier compile error (e.g. synacode stopping on an undefined Move) halted before emit. Now that synacode resolves, it reaches emit and trips.

Root cause

compiler/lexer.inc:1194:

if CaseEqual(command, 'R') and PasDirectiveActive then
  ReadPasDirectiveFile(fname);

Unconditional — it never checks whether the char immediately after R is +/- (the range-check toggle form). Latent since fd1c3b4 (2026-05-30, "Phase 4: embedded resources"); not a v50 regression.

Fix

In the {$R} branch, if the next non-space char is + or - (and the directive body is just that toggle, optionally followed by }), treat it as the range-check switch — a no-op like {$Q±}/{$I±} — and do not call ReadPasDirectiveFile / register a resource. Only the {$R name file} / {$R *.res} forms register a resource. (FPC also has {$R+}/{$R-} vs {$R filename}; same disambiguation.)

Done when

• {$R-} / {$R+} compile as no-op range switches (no pending resource, no emit error); {$R name file} still links a resource.
• synacode gets past emit (next gap, if any, is a genuine RTL/codegen one).
• Regression test under make test (a program with {$R-} builds and runs).
• Self-host fixedpoint byte-identical.

Log

• 2026-06-24 — FIXED (Track A). lexer.inc {$R} branch now skips resource handling when the directive body begins with +/- (the range-check toggle {$R+}/{$R-}), treating it as a no-op like {$Q±}/{$I±}; only {$R name file} / {$R *.res} register a resource. Regression test/test_r_directive.pas in make test. Self-host fixedpoint byte-identical.