LibWasm: Implement the br.table instruction

Unlike its name, this instruction has nothing to do with tables, it's
just a very simple switch-case instruction.
This commit is contained in:
Ali Mohammad Pur 2021-06-04 03:27:51 +04:30 committed by Ali Mohammad Pur
parent 9db418e1fb
commit c392a0cf7f
Notes: sideshowbarker 2024-07-18 16:54:34 +09:00
2 changed files with 16 additions and 2 deletions

View file

@ -66,6 +66,9 @@ Result Configuration::execute(Interpreter& interpreter)
if (interpreter.did_trap())
return Trap {};
if (stack().size() <= frame().arity() + 1)
return Trap {};
Vector<Value> results;
results.ensure_capacity(frame().arity());
for (size_t i = 0; i < frame().arity(); ++i)

View file

@ -122,6 +122,7 @@ void BytecodeInterpreter::call_address(Configuration& configuration, FunctionAdd
const FunctionType* type { nullptr };
instance->visit([&](const auto& function) { type = &function.type(); });
TRAP_IF_NOT(type);
TRAP_IF_NOT(configuration.stack().entries().size() > type->parameters().size());
Vector<Value> args;
args.ensure_capacity(type->parameters().size());
auto span = configuration.stack().entries().span().slice_from_end(type->parameters().size());
@ -506,8 +507,18 @@ void BytecodeInterpreter::interpret(Configuration& configuration, InstructionPoi
return;
return branch_to_label(configuration, instruction.arguments().get<LabelIndex>());
}
case Instructions::br_table.value():
goto unimplemented;
case Instructions::br_table.value(): {
auto& arguments = instruction.arguments().get<Instruction::TableBranchArgs>();
auto entry = configuration.stack().pop();
TRAP_IF_NOT(entry.has<Value>());
auto maybe_i = entry.get<Value>().to<i32>();
TRAP_IF_NOT(maybe_i.has_value());
TRAP_IF_NOT(maybe_i.value() >= 0);
size_t i = *maybe_i;
if (i < arguments.labels.size())
return branch_to_label(configuration, arguments.labels[i]);
return branch_to_label(configuration, arguments.default_);
}
case Instructions::call.value(): {
auto index = instruction.arguments().get<FunctionIndex>();
TRAP_IF_NOT(index.value() < configuration.frame().module().functions().size());