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LibJS: Stop generating switch case statements on block termination

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After we terminate a block (e.g. break, continue), we cannot generate
anymore bytecode for the block. This caused us to crash with this
example code:
```
a = 0;
switch (a) {
    case 0:
        break;
        console.log("hello world");
}
```
Anything after a block terminating instruction is considered
unreachable code, so we can safely skip any statements after it.
This commit is contained in:
Luke Wilde 2022-03-15 01:43:44 +00:00 • committed by Ali Mohammad Pur
parent 6f29ccaa5a
commit 1fc6bbcdc3
1 changed files with 2 additions and 0 deletions
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2
Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
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@ -1627,6 +1627,8 @@ Bytecode::CodeGenerationErrorOr<void> SwitchStatement::generate_bytecode(Bytecod
generator.emit<Bytecode::Op::LoadImmediate>(js_undefined()); generator.emit<Bytecode::Op::LoadImmediate>(js_undefined());
for (auto& statement : switch_case.children()) { for (auto& statement : switch_case.children()) {
TRY(statement.generate_bytecode(generator)); TRY(statement.generate_bytecode(generator));
if (generator.is_current_block_terminated())
break;
} }
if (!generator.is_current_block_terminated()) { if (!generator.is_current_block_terminated()) {
auto next_block = current_block; auto next_block = current_block;