From 0356239f3e4d31a0b19e8582403edd896100db69 Mon Sep 17 00:00:00 2001
From: Luke Wilde <lukew@serenityos.org>
Date: Mon, 14 Mar 2022 02:13:33 +0000
Subject: [PATCH] LibJS/Bytecode: Unconditionally end break/continuable scopes

Previously we would only end these scopes if the block was not
terminated. If the block was generated, we would not end the scope
and would generate other bytecode with these scopes still open.

These functions do not generate any code, so they can be used even if
the current block is terminated. The enter and end scope functions are
only used to track where to unwind to when break/continue are used.
---
 Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp b/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
index b26e55cc587..cce2818b6b4 100644
--- a/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
+++ b/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
@@ -642,12 +642,13 @@ Bytecode::CodeGenerationErrorOr<void> WhileStatement::generate_bytecode(Bytecode
     generator.begin_continuable_scope(Bytecode::Label { test_block });
     generator.begin_breakable_scope(Bytecode::Label { end_block });
     TRY(m_body->generate_bytecode(generator));
+    generator.end_breakable_scope();
+    generator.end_continuable_scope();
+
     if (!generator.is_current_block_terminated()) {
         generator.emit<Bytecode::Op::Jump>().set_targets(
             Bytecode::Label { test_block },
             {});
-        generator.end_continuable_scope();
-        generator.end_breakable_scope();
         generator.switch_to_basic_block(end_block);
         generator.emit<Bytecode::Op::Load>(result_reg);
     }
@@ -687,12 +688,13 @@ Bytecode::CodeGenerationErrorOr<void> DoWhileStatement::generate_bytecode(Byteco
     generator.begin_continuable_scope(Bytecode::Label { test_block });
     generator.begin_breakable_scope(Bytecode::Label { end_block });
     TRY(m_body->generate_bytecode(generator));
+    generator.end_breakable_scope();
+    generator.end_continuable_scope();
+
     if (!generator.is_current_block_terminated()) {
         generator.emit<Bytecode::Op::Jump>().set_targets(
             Bytecode::Label { test_block },
             {});
-        generator.end_continuable_scope();
-        generator.end_breakable_scope();
         generator.switch_to_basic_block(end_block);
         generator.emit<Bytecode::Op::Load>(result_reg);
     }
@@ -756,6 +758,7 @@ Bytecode::CodeGenerationErrorOr<void> ForStatement::generate_bytecode(Bytecode::
     generator.begin_continuable_scope(Bytecode::Label { *update_block_ptr });
     generator.begin_breakable_scope(Bytecode::Label { end_block });
     TRY(m_body->generate_bytecode(generator));
+    generator.end_breakable_scope();
     generator.end_continuable_scope();
 
     if (!generator.is_current_block_terminated()) {
@@ -772,7 +775,6 @@ Bytecode::CodeGenerationErrorOr<void> ForStatement::generate_bytecode(Bytecode::
             Bytecode::Label { *test_block_ptr },
             {});
 
-        generator.end_breakable_scope();
         generator.switch_to_basic_block(end_block);
         generator.emit<Bytecode::Op::Load>(result_reg);
     }