From f91a10ae153f41c46729605ecf0023d11ada07b8 Mon Sep 17 00:00:00 2001
From: nsfisis <nsfisis@gmail.com>
Date: Tue, 29 Jul 2025 06:09:06 +0900
Subject: feat: implement empty statements (only semicolon)

---
 ast.c        | 1 +
 codegen.c    | 5 +++++
 parse.c      | 7 +++++++
 tests/064.sh | 6 ++----
 tests/065.sh | 8 ++++++++
 5 files changed, 23 insertions(+), 4 deletions(-)
 create mode 100644 tests/065.sh

diff --git a/ast.c b/ast.c
index ad5b83f..70ccb20 100644
--- a/ast.c
+++ b/ast.c
@@ -84,6 +84,7 @@ int type_alignof(Type* ty) {
 
 enum AstNodeKind {
     AstNodeKind_unknown,
+    AstNodeKind_nop,
 
     AstNodeKind_assign_expr,
     AstNodeKind_binary_expr,
diff --git a/codegen.c b/codegen.c
index d290e95..4bb15e2 100644
--- a/codegen.c
+++ b/codegen.c
@@ -400,6 +400,9 @@ void codegen_expr_stmt(CodeGen* g, AstNode* ast) {
 void codegen_var_decl(CodeGen* g, AstNode* ast) {
 }
 
+void codegen_nop(CodeGen* g, AstNode* ast) {
+}
+
 void codegen_block_stmt(CodeGen* g, AstNode* ast) {
     int i;
     for (i = 0; i < ast->node_len; ++i) {
@@ -427,6 +430,8 @@ void codegen_stmt(CodeGen* g, AstNode* ast) {
         codegen_expr_stmt(g, ast);
     } else if (ast->kind == AstNodeKind_lvar_decl) {
         codegen_var_decl(g, ast);
+    } else if (ast->kind == AstNodeKind_nop) {
+        codegen_nop(g, ast);
     } else {
         unreachable();
     }
diff --git a/parse.c b/parse.c
index 9c635be..469ed49 100644
--- a/parse.c
+++ b/parse.c
@@ -703,6 +703,11 @@ AstNode* parse_block_stmt(Parser* p) {
     return list;
 }
 
+AstNode* parse_empty_stmt(Parser* p) {
+    next_token(p);
+    return ast_new(AstNodeKind_nop);
+}
+
 AstNode* parse_stmt(Parser* p) {
     Token* t = peek_token(p);
     if (t->kind == TokenKind_keyword_return) {
@@ -721,6 +726,8 @@ AstNode* parse_stmt(Parser* p) {
         return parse_continue_stmt(p);
     } else if (t->kind == TokenKind_brace_l) {
         return parse_block_stmt(p);
+    } else if (t->kind == TokenKind_semicolon) {
+        return parse_empty_stmt(p);
     } else if (is_type_token(p, t)) {
         return parse_var_decl(p);
     } else {
diff --git a/tests/064.sh b/tests/064.sh
index 80fba4f..c3b6028 100644
--- a/tests/064.sh
+++ b/tests/064.sh
@@ -14,9 +14,7 @@ EOF
 
 bash ../../test_exit_code.sh 0 <<'EOF'
 int main() {
-    if (1) {
-    } else {
-        return 1;
-    }
+    if (1);
+    else return 1;
 }
 EOF
diff --git a/tests/065.sh b/tests/065.sh
new file mode 100644
index 0000000..b644bed
--- /dev/null
+++ b/tests/065.sh
@@ -0,0 +1,8 @@
+set -e
+
+cat <<'EOF' > expected
+EOF
+
+bash ../../test_diff.sh <<'EOF'
+int main() { ; }
+EOF
-- 
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