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LibWasm: Fix nested structured instruction parsing

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Previously, the ip would not be propagated correctly, and we would
produce invalid jumps when more than one level of nesting was involved.
This makes loops work :P
This commit is contained in:
Ali Mohammad Pur 2021-05-18 00:23:41 +04:30 • committed by Linus Groh
parent 29b193d25d
commit 207379165f
2 changed files with 12 additions and 8 deletions
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11
Userland/Libraries/LibWasm/AbstractMachine/Interpreter.cpp
View file

@ -28,10 +28,12 @@ void Interpreter::interpret(Configuration& configuration)
while (current_ip_value < max_ip_value) {
auto& instruction = instructions[current_ip_value.value()];
auto old_ip = current_ip_value;
interpret(configuration, current_ip_value, instruction);
if (m_do_trap)
return;
++current_ip_value;
if (current_ip_value == old_ip) // If no jump occurred
++current_ip_value;
}
}
@ -46,18 +48,19 @@ void Interpreter::branch_to_label(Configuration& configuration, LabelIndex index
size_t drop_count = index.value() + 1;
for (; !configuration.stack().is_empty();) {
auto entry = configuration.stack().pop();
auto& entry = configuration.stack().peek();
if (entry.has<NonnullOwnPtr<Label>>()) {
if (drop_count-- == 0)
break;
}
configuration.stack().pop();
}
// Push results in reverse
for (size_t i = results.size(); i > 0; --i)
configuration.stack().push(move(static_cast<Vector<NonnullOwnPtr<Value>>&>(results)[i - 1]));
configuration.ip() = label->continuation() + 1;
configuration.ip() = label->continuation();
}
ReadonlyBytes Interpreter::load_from_memory(Configuration& configuration, const Instruction& instruction, size_t size)
@ -321,7 +324,7 @@ void Interpreter::interpret(Configuration& configuration, InstructionPointer& ip
auto& args = instruction.arguments().get<Instruction::StructuredInstructionArgs>();
if (args.block_type.kind() != BlockType::Empty)
arity = 1;
configuration.stack().push(make<Label>(arity, ip.value() + 1));
configuration.stack().push(make<Label>(arity, ip.value()));
return;
}
case Instructions::if_.value(): {

9
Userland/Libraries/LibWasm/Parser/Parser.cpp
View file

@ -82,7 +82,7 @@ struct ParseUntilAnyOfResult {
Vector<T> values;
};
template<typename T, u8... terminators, typename... Args>
static ParseResult<ParseUntilAnyOfResult<T>> parse_until_any_of(InputStream& stream, Args... args) requires(requires(InputStream& stream, Args... args) { T::parse(stream, args...); })
static ParseResult<ParseUntilAnyOfResult<T>> parse_until_any_of(InputStream& stream, Args&... args) requires(requires(InputStream& stream, Args... args) { T::parse(stream, args...); })
{
ScopeLogger<WASM_BINPARSER_DEBUG> logger;
ReconsumableStream new_stream { stream };
@ -305,7 +305,8 @@ ParseResult<Vector<Instruction>> Instruction::parse(InputStream& stream, Instruc
result.value().values.append(Instruction { Instructions::structured_end });
// Transform op(..., instr*) -> op(...) instr* op(end(ip))
result.value().values.prepend(Instruction { opcode, StructuredInstructionArgs { BlockType { block_type.release_value() }, ++ip, {} } });
result.value().values.prepend(Instruction { opcode, StructuredInstructionArgs { BlockType { block_type.release_value() }, ip.value(), {} } });
++ip;
return result.release_value().values;
}
@ -314,7 +315,7 @@ ParseResult<Vector<Instruction>> Instruction::parse(InputStream& stream, Instruc
instructions.append(result.release_value().values);
instructions.append(Instruction { Instructions::structured_else });
++ip;
else_ip = ip;
else_ip = ip.value();
}
// if with else
{
@ -324,7 +325,7 @@ ParseResult<Vector<Instruction>> Instruction::parse(InputStream& stream, Instruc
instructions.append(result.release_value().values);
instructions.append(Instruction { Instructions::structured_end });
++ip;
end_ip = ip;
end_ip = ip.value();
}
instructions.prepend(Instruction { opcode, StructuredInstructionArgs { BlockType { block_type.release_value() }, end_ip, else_ip } });