Struct cranelift_wasm::FuncTranslator

pub struct FuncTranslator { /* private fields */ }

WebAssembly to Cranelift IR function translator.

A FuncTranslator is used to translate a binary WebAssembly function into Cranelift IR guided by a FuncEnvironment object. A single translator instance can be reused to translate multiple functions which will reduce heap allocation traffic.

Implementations

impl FuncTranslator

pub fn new() -> Self

Create a new translator.

Examples found in repository

src/environ/dummy.rs (line 164)

    pub fn new(config: TargetFrontendConfig, debug_info: bool) -> Self {
        Self {
            info: DummyModuleInfo::new(config),
            trans: FuncTranslator::new(),
            func_bytecode_sizes: Vec::new(),
            debug_info,
            module_name: None,
            function_names: SecondaryMap::new(),
            expected_reachability: None,
        }
    }

pub fn context(&mut self) -> &mut FunctionBuilderContext

Returns the underlying FunctionBuilderContext that this translator uses.

pub fn translate<FE: FuncEnvironment + ?Sized>(
    &mut self,
    validator: &mut FuncValidator<impl WasmModuleResources>,
    code: &[u8],
    code_offset: usize,
    func: &mut Function,
    environ: &mut FE
) -> WasmResult<()>

Translate a binary WebAssembly function.

The code slice contains the binary WebAssembly function code as it appears in the code section of a WebAssembly module, not including the initial size of the function code. The slice is expected to contain two parts:

• The declaration of locals, and
• The function body as an expression.

See the WebAssembly specification.

The Cranelift IR function func should be completely empty except for the func.signature and func.name fields. The signature may contain special-purpose arguments which are not regarded as WebAssembly local variables. Any signature arguments marked as ArgumentPurpose::Normal are made accessible as WebAssembly local variables.

pub fn translate_body<FE: FuncEnvironment + ?Sized>(
    &mut self,
    validator: &mut FuncValidator<impl WasmModuleResources>,
    body: FunctionBody<'_>,
    func: &mut Function,
    environ: &mut FE
) -> WasmResult<()>

Translate a binary WebAssembly function from a FunctionBody.

Examples found in repository

src/func_translator.rs (lines 70-75)

    pub fn translate<FE: FuncEnvironment + ?Sized>(
        &mut self,
        validator: &mut FuncValidator<impl WasmModuleResources>,
        code: &[u8],
        code_offset: usize,
        func: &mut ir::Function,
        environ: &mut FE,
    ) -> WasmResult<()> {
        self.translate_body(
            validator,
            FunctionBody::new(code_offset, code),
            func,
            environ,
        )
    }

src/environ/dummy.rs (line 861)

    fn define_function_body(
        &mut self,
        mut validator: FuncValidator<ValidatorResources>,
        body: FunctionBody<'data>,
    ) -> WasmResult<()> {
        self.func_bytecode_sizes
            .push(body.get_binary_reader().bytes_remaining());
        let func = {
            let mut func_environ =
                DummyFuncEnvironment::new(&self.info, self.expected_reachability.clone());
            let func_index =
                FuncIndex::new(self.get_num_func_imports() + self.info.function_bodies.len());

            let sig = func_environ.vmctx_sig(self.get_func_type(func_index));
            let mut func =
                ir::Function::with_name_signature(UserFuncName::user(0, func_index.as_u32()), sig);

            if self.debug_info {
                func.collect_debug_info();
            }

            self.trans
                .translate_body(&mut validator, body, &mut func, &mut func_environ)?;
            func
        };
        self.info.function_bodies.push(func);
        Ok(())
    }