beenull/ladybird
1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2024-11-22 15:40:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 6

LibWasm: Fix nested structured instruction parsing

Browse source 
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
Notes: sideshowbarker 2024-07-18 17:39:30 +09:00 
Author: https://github.com/alimpfard
Commit: https://github.com/SerenityOS/serenity/commit/207379165f2
Pull-request: https://github.com/SerenityOS/serenity/pull/7239
Reviewed-by: https://github.com/linusg
2 changed files with 12 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

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 } });