stage1 整理代码 提供更多错误信息

stage1/spl_emit.c

@@ -231,3 +231,49 @@ void spl_emit_store_init(spl_comp_t *ctx, int var_offset, int var_type_idx) {
         emit_store_to_laddr(&ctx->emit, var_offset, bt);
     }
 }
+
+void spl_emit_defer(spl_comp_t *ctx) {
+    if (ctx->defer_count >= DEFER_MAX)
+        return;
+
+    spl_val_t jmp_skip = emit_jmp_here(&ctx->emit);
+
+    spl_defer_entry_t *e = &ctx->defer_stack[ctx->defer_count];
+    e->body_start = jmp_skip + 1;
+    e->jmp_exit = 0;
+    e->depth = ctx->scope_depth;
+    e->count_at_decl = ctx->defer_count;
+    ctx->defer_count++;
+}
+
+void spl_emit_defer_epilogue(spl_comp_t *ctx, int depth) {
+    for (int i = 0; i < ctx->defer_count; i++) {
+        if (ctx->defer_stack[i].depth != depth)
+            continue;
+        spl_defer_entry_t *e = &ctx->defer_stack[i];
+
+        spl_val_t skip_addr = e->body_start - 1;
+        spl_val_t skip_target = e->jmp_exit + 1;
+        emit_patch(&ctx->emit, skip_addr, skip_target - skip_addr - 1);
+    }
+
+    for (int i = ctx->defer_count - 1; i >= 0; i--) {
+        if (ctx->defer_stack[i].depth != depth)
+            continue;
+        spl_defer_entry_t *e = &ctx->defer_stack[i];
+
+        spl_val_t here = vec_size(ctx->prog.insns);
+        spl_val_t jmp_offset = (spl_val_t)((isize)e->body_start - (isize)here - 1);
+        emit_jmp(&ctx->emit, jmp_offset);
+
+        if (e->jmp_exit > 0)
+            emit_patch(&ctx->emit, e->jmp_exit, here + 1 - e->jmp_exit - 1);
+    }
+
+    int new_count = 0;
+    for (int i = 0; i < ctx->defer_count; i++) {
+        if (ctx->defer_stack[i].depth != depth)
+            ctx->defer_stack[new_count++] = ctx->defer_stack[i];
+    }
+    ctx->defer_count = new_count;
+}