Method start_func

crates/tinywasm/src/instance.rs:619–646

Get the start function of the module Returns None if the module has no start function If no start function is specified, also checks for a `_start` function in the exports ## Example ```rust # fn main() -> tinywasm::Result<()> { # use tinywasm::{ModuleInstance, Store}; # let wasm = wat::parse_str(r#" # (module # (func (export "_start")) # ) # "#).expect("valid wat"); # let module =

(&self, store: &Store)

    ///
    /// See <https://webassembly.github.io/spec/core/syntax/modules.html#start-function>
    pub fn start_func(&self, store: &Store) -> Result<Option<Function>> {
        self.validate_store(store)?;

        let func_addr = match self.0.func_start {
            Some(func_index) => func_index,
            None => {
                // Alternatively, check for a _start function in the exports.
                let Some(ExternVal::Func(func_addr)) = self.export_addr("_start") else {
                    return Ok(None);
                };

                return Ok(Some(Function {
                    item: crate::StoreItem::new(self.0.store_id, func_addr),
                    module_addr: self.id(),
                    addr: func_addr,
                    ty: store.state.get_func(func_addr).ty().clone(),
                }));
            }
        };

        let func_addr = self.resolve_func_addr(func_addr);
        Ok(Some(Function {
            item: crate::StoreItem::new(self.0.store_id, func_addr),
            module_addr: self.id(),
            addr: func_addr,
            ty: store.state.get_func(func_addr).ty().clone(),
        }))
    }

    /// Invoke the start function of the module
    ///