stage0 支持类gdb的调试vm手段

stage0/spl_mcode.c

@@ -39,6 +39,8 @@ void spl_prog_drop(spl_prog_t *prog) {
     vec_for(prog->strtab, i) { free((void *)vec_at(prog->strtab, i)); }
     vec_free(prog->strtab);
     map_free(prog->symtab);
+    free(prog->debug);
+    prog->debug = NULL;
 }
 
 /* ---- LE read/write helpers ---- */
@@ -201,6 +203,23 @@ int spl_prog_load_from_file(const char *fname, spl_prog_t *prog) {
         vec_push(prog->gdata, entry);
     }
 
+    /* ---- debug 段（splc0 -g 追加在文件尾部） ---- */
+    prog->debug = NULL;
+    prog->debug_size = 0;
+    {
+        ptrdiff_t used = p - data;
+        if (used >= 0 && (usize)used < (usize)len) {
+            size_t dlen = (size_t)len - (size_t)used;
+            char *dbg = (char *)malloc(dlen + 1);
+            if (dbg) {
+                memcpy(dbg, data + used, dlen);
+                dbg[dlen] = 0;
+                prog->debug = dbg;
+                prog->debug_size = dlen;
+            }
+        }
+    }
+
     free(data);
     return 0;
 }