Function cranelift_wasm::get_vmctx_value_label

source · 
pub fn get_vmctx_value_label() -> ValueLabel
Expand description

Special VMContext value label. It is tracked as 0xffff_fffe label.

Examples found in repository?
src/func_translator.rs (line 149)
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fn declare_wasm_parameters<FE: FuncEnvironment + ?Sized>(
    builder: &mut FunctionBuilder,
    entry_block: Block,
    environ: &FE,
) -> usize {
    let sig_len = builder.func.signature.params.len();
    let mut next_local = 0;
    for i in 0..sig_len {
        let param_type = builder.func.signature.params[i];
        // There may be additional special-purpose parameters in addition to the normal WebAssembly
        // signature parameters. For example, a `vmctx` pointer.
        if environ.is_wasm_parameter(&builder.func.signature, i) {
            // This is a normal WebAssembly signature parameter, so create a local for it.
            let local = Variable::new(next_local);
            builder.declare_var(local, param_type.value_type);
            next_local += 1;

            let param_value = builder.block_params(entry_block)[i];
            builder.def_var(local, param_value);
        }
        if param_type.purpose == ir::ArgumentPurpose::VMContext {
            let param_value = builder.block_params(entry_block)[i];
            builder.set_val_label(param_value, get_vmctx_value_label());
        }
    }

    next_local
}