From b96118b5d1975e82aa573b322d975ef165671b1f Mon Sep 17 00:00:00 2001
From: Ali Mohammad Pur <ali.mpfard@gmail.com>
Date: Wed, 10 Nov 2021 22:22:26 +0330
Subject: [PATCH] LibJS: Fix codegen for nodes after try statements without
 'finally'

Previously we were just dropping them on the ground :P
---
 .../Libraries/LibJS/Bytecode/ASTCodegen.cpp     | 11 +++++++++--
 Userland/Libraries/LibJS/Bytecode/Instruction.h |  1 +
 Userland/Libraries/LibJS/Bytecode/Op.cpp        | 17 +++++++++++++++++
 Userland/Libraries/LibJS/Bytecode/Op.h          | 16 ++++++++++++++++
 4 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp b/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
index f7a59926c5..2f4d6a3b6d 100644
--- a/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
+++ b/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
@@ -1189,8 +1189,15 @@ void TryStatement::generate_bytecode(Bytecode::Generator& generator) const
 
     generator.switch_to_basic_block(target_block);
     m_block->generate_bytecode(generator);
-    if (m_finalizer && !generator.is_current_block_terminated())
-        generator.emit<Bytecode::Op::Jump>(finalizer_target);
+    if (!generator.is_current_block_terminated()) {
+        if (m_finalizer) {
+            generator.emit<Bytecode::Op::Jump>(finalizer_target);
+        } else {
+            auto& block = generator.make_block();
+            generator.emit<Bytecode::Op::FinishUnwind>(Bytecode::Label { block });
+            next_block = &block;
+        }
+    }
 
     generator.switch_to_basic_block(next_block ? *next_block : saved_block);
 }
diff --git a/Userland/Libraries/LibJS/Bytecode/Instruction.h b/Userland/Libraries/LibJS/Bytecode/Instruction.h
index 941a990b40..d9da87b4d1 100644
--- a/Userland/Libraries/LibJS/Bytecode/Instruction.h
+++ b/Userland/Libraries/LibJS/Bytecode/Instruction.h
@@ -24,6 +24,7 @@
     O(Div)                           \
     O(EnterUnwindContext)            \
     O(Exp)                           \
+    O(FinishUnwind)                  \
     O(GetById)                       \
     O(GetByValue)                    \
     O(GetIterator)                   \
diff --git a/Userland/Libraries/LibJS/Bytecode/Op.cpp b/Userland/Libraries/LibJS/Bytecode/Op.cpp
index 32655dfe74..b2ea9b97f7 100644
--- a/Userland/Libraries/LibJS/Bytecode/Op.cpp
+++ b/Userland/Libraries/LibJS/Bytecode/Op.cpp
@@ -446,6 +446,18 @@ void EnterUnwindContext::replace_references_impl(BasicBlock const& from, BasicBl
         m_finalizer_target = Label { to };
 }
 
+void FinishUnwind::execute_impl(Bytecode::Interpreter& interpreter) const
+{
+    interpreter.leave_unwind_context();
+    interpreter.jump(m_next_target);
+}
+
+void FinishUnwind::replace_references_impl(BasicBlock const& from, BasicBlock const& to)
+{
+    if (&m_next_target.block() == &from)
+        m_next_target = Label { to };
+}
+
 void LeaveUnwindContext::execute_impl(Bytecode::Interpreter& interpreter) const
 {
     interpreter.leave_unwind_context();
@@ -751,6 +763,11 @@ String EnterUnwindContext::to_string_impl(Bytecode::Executable const&) const
     return String::formatted("EnterUnwindContext handler:{} finalizer:{} entry:{}", handler_string, finalizer_string, m_entry_point);
 }
 
+String FinishUnwind::to_string_impl(const Bytecode::Executable&) const
+{
+    return String::formatted("FinishUnwind next:{}", m_next_target);
+}
+
 String LeaveUnwindContext::to_string_impl(Bytecode::Executable const&) const
 {
     return "LeaveUnwindContext";
diff --git a/Userland/Libraries/LibJS/Bytecode/Op.h b/Userland/Libraries/LibJS/Bytecode/Op.h
index 7043f6617c..ad848d7cc9 100644
--- a/Userland/Libraries/LibJS/Bytecode/Op.h
+++ b/Userland/Libraries/LibJS/Bytecode/Op.h
@@ -610,6 +610,22 @@ public:
     void replace_references_impl(BasicBlock const&, BasicBlock const&) { }
 };
 
+class FinishUnwind final : public Instruction {
+public:
+    FinishUnwind(Label next)
+        : Instruction(Type::FinishUnwind)
+        , m_next_target(move(next))
+    {
+    }
+
+    void execute_impl(Bytecode::Interpreter&) const;
+    String to_string_impl(Bytecode::Executable const&) const;
+    void replace_references_impl(BasicBlock const&, BasicBlock const&);
+
+private:
+    Label m_next_target;
+};
+
 class ContinuePendingUnwind final : public Instruction {
 public:
     constexpr static bool IsTerminator = true;