stage1 支持任意顺序声明 使用eval求值的机制

stage1/spl_ir.c

@@ -387,6 +387,27 @@ spl_ir_func_ref_t spl_ir_builder_fn_begin(spl_ir_builder_t *b, const char *name,
     return fid;
 }
 
+spl_ir_func_ref_t spl_ir_builder_fn_reserve(spl_ir_builder_t *b, const char *name,
+                                            spl_type_id_t fn_tid) {
+    spl_ir_func_ref_t fid = spl_ir_alloc_fn(&b->ir);
+    spl_ir_func_t *f = spl_ir_func(&b->ir, fid);
+    f->name = name;
+    vec_init(f->attrs);
+    f->fn_tid = fn_tid;
+    return fid;
+}
+
+void spl_ir_builder_fn_begin_at(spl_ir_builder_t *b, spl_ir_func_ref_t fid) {
+    if (b->current_fn && b->current_fn != fid) {
+        spl_ir_builder_fn_end(b);
+    }
+    b->current_fn = fid;
+    b->current_block = 0;
+    b->blocks.size = 0;
+    b->fixups.size = 0;
+    b->terminated = false;
+}
+
 void spl_ir_builder_fn_end(spl_ir_builder_t *b) {
     spl_ir_func_t *f = spl_ir_func(&b->ir, b->current_fn);
     if (!f) {