Files
wasmtime/lib/wasm/src/module_translator.rs
2018-07-19 06:39:56 -07:00

120 lines
4.5 KiB
Rust

//! Translation skeleton that traverses the whole WebAssembly module and call helper functions
//! to deal with each part of it.
use cranelift_codegen::timing;
use environ::{ModuleEnvironment, WasmError, WasmResult};
use sections_translator::{
parse_code_section, parse_data_section, parse_elements_section, parse_export_section,
parse_function_section, parse_function_signatures, parse_global_section, parse_import_section,
parse_memory_section, parse_start_section, parse_table_section,
};
use wasmparser::{Parser, ParserInput, ParserState, SectionCode, WasmDecoder};
/// Translate a sequence of bytes forming a valid Wasm binary into a list of valid Cranelift IR
/// [`Function`](../codegen/ir/function/struct.Function.html).
/// Returns the functions and also the mappings for imported functions and signature between the
/// indexes in the wasm module and the indexes inside each functions.
pub fn translate_module<'data>(
data: &'data [u8],
environ: &mut ModuleEnvironment<'data>,
) -> WasmResult<()> {
let _tt = timing::wasm_translate_module();
let mut parser = Parser::new(data);
match *parser.read() {
ParserState::BeginWasm { .. } => {}
ParserState::Error(e) => {
return Err(WasmError::from_binary_reader_error(e));
}
ref s => panic!("modules should begin properly: {:?}", s),
}
let mut next_input = ParserInput::Default;
loop {
match *parser.read_with_input(next_input) {
ParserState::BeginSection {
code: SectionCode::Type,
..
} => {
parse_function_signatures(&mut parser, environ)?;
next_input = ParserInput::Default;
}
ParserState::BeginSection {
code: SectionCode::Import,
..
} => {
parse_import_section(&mut parser, environ)?;
next_input = ParserInput::Default;
}
ParserState::BeginSection {
code: SectionCode::Function,
..
} => {
parse_function_section(&mut parser, environ)?;
next_input = ParserInput::Default;
}
ParserState::BeginSection {
code: SectionCode::Table,
..
} => {
parse_table_section(&mut parser, environ)?;
}
ParserState::BeginSection {
code: SectionCode::Memory,
..
} => {
parse_memory_section(&mut parser, environ)?;
next_input = ParserInput::Default;
}
ParserState::BeginSection {
code: SectionCode::Global,
..
} => {
parse_global_section(&mut parser, environ)?;
next_input = ParserInput::Default;
}
ParserState::BeginSection {
code: SectionCode::Export,
..
} => {
parse_export_section(&mut parser, environ)?;
next_input = ParserInput::Default;
}
ParserState::BeginSection {
code: SectionCode::Start,
..
} => {
parse_start_section(&mut parser, environ)?;
next_input = ParserInput::Default;
}
ParserState::BeginSection {
code: SectionCode::Element,
..
} => {
parse_elements_section(&mut parser, environ)?;
next_input = ParserInput::Default;
}
ParserState::BeginSection {
code: SectionCode::Code,
..
} => parse_code_section(&mut parser, environ)?,
ParserState::EndSection => {
next_input = ParserInput::Default;
}
ParserState::EndWasm => return Ok(()),
ParserState::BeginSection {
code: SectionCode::Data,
..
} => {
parse_data_section(&mut parser, environ)?;
}
ParserState::BeginSection {
code: SectionCode::Custom { .. },
..
} => {
// Ignore unknown custom sections.
next_input = ParserInput::SkipSection;
}
ParserState::Error(e) => return Err(WasmError::from_binary_reader_error(e)),
_ => panic!("wrong content in the preamble"),
};
}
}