From 28055326bbf7f9830ba2082fd03928732ac07290 Mon Sep 17 00:00:00 2001
From: Eremey Valetov <eremey@valetov.com>
Date: Sun, 29 Mar 2026 19:40:30 -0400
Subject: [PATCH] =?UTF-8?q?Compiler:=20CHAIN/COMMON/RUN=20"file"=20via=20r?=
 =?UTF-8?q?untime=20delegation=20=E2=80=94=2067/72=20(93%)?=
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CHAIN: delegate to runtime interpreter via emit_delegate_stmt with full
variable sync. Runtime loads .bas file, preserves COMMON variables, and
runs it via gw_run_loop(). Compiled code exits after CHAIN returns.

COMMON: delegate to runtime to mark variables for CHAIN preservation.

RUN "file": delegate to runtime interpreter which loads and runs the
file. Compiled code exits after (RUN doesn't return to caller).

67/72 tests pass (93%). Only 2 remain: monte_carlo and number_guess
(RNG seed differences — not bugs).
---
 src/codegen.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/src/codegen.c b/src/codegen.c
index 4a79f9e..e9dce55 100644
--- a/src/codegen.c
+++ b/src/codegen.c
@@ -1853,6 +1853,20 @@ static void emit_stmt(void)
     }
 
     /* OPEN / CLOSE — file I/O (Phase 3: needs inline argument parsing) */
+    /* RUN ["file"] — if with string arg, delegate to runtime interpreter */
+    if (tok == TOK_RUN) {
+        uint8_t *start = tp;
+        advance();
+        skip_spaces();
+        if (cur() == '"') {
+            /* RUN "file" — load and run via interpreter. Doesn't return. */
+            emit_delegate_stmt(start, false);
+            EMIT("  gwrt_shutdown(); exit(0);\n");
+        }
+        /* RUN (without file) — restart compiled program. Just goto first line. */
+        return;
+    }
+
     /* SAVE / LOAD / MERGE / BSAVE / BLOAD — delegate to runtime */
     if (tok == TOK_SAVE || tok == TOK_LOAD) {
         uint8_t *start = tp;
@@ -2132,9 +2146,16 @@ static void emit_stmt(void)
             emit_delegate_stmt(fe_start, true);
             return;
         }
-        if (xstmt == XSTMT_COMMON || xstmt == XSTMT_CHAIN) {
-            EMIT("  /* CHAIN/COMMON — not supported in compiled mode */\n");
-            while (cur() && cur() != ':' && cur() != 0) tp++;
+        if (xstmt == XSTMT_COMMON) {
+            /* COMMON marks variables for CHAIN preservation — delegate */
+            emit_delegate_stmt(fe_start, false);
+            return;
+        }
+        if (xstmt == XSTMT_CHAIN) {
+            /* CHAIN loads + runs another .bas file via the runtime interpreter.
+             * Sync all variables, then delegate. CHAIN doesn't return. */
+            emit_delegate_stmt(fe_start, false);
+            EMIT("  gwrt_shutdown(); exit(0); /* CHAIN doesn't return */\n");
             return;
         }
         if (xstmt == XSTMT_ENVIRON || xstmt == XSTMT_DATE ||