852 lines
31 KiB
Rust
852 lines
31 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use core::prelude::*;
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use back::abi;
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use lib::llvm::llvm;
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use lib::llvm::ValueRef;
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use lib;
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use metadata::csearch;
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use middle::trans::base::*;
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use middle::trans::build::*;
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use middle::trans::callee::*;
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use middle::trans::callee;
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use middle::trans::common::*;
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use middle::trans::expr::{SaveIn, Ignore};
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use middle::trans::expr;
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use middle::trans::glue;
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use middle::trans::monomorphize;
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use middle::trans::type_of::*;
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use middle::ty;
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use middle::typeck;
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use util::common::indenter;
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use util::ppaux::Repr;
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use middle::trans::type_::Type;
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use core::str;
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use core::vec;
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use syntax::ast_map::{path, path_mod, path_name};
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use syntax::ast_util;
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use syntax::{ast, ast_map};
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/**
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The main "translation" pass for methods. Generates code
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for non-monomorphized methods only. Other methods will
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be generated once they are invoked with specific type parameters,
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see `trans::base::lval_static_fn()` or `trans::base::monomorphic_fn()`.
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*/
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pub fn trans_impl(ccx: @mut CrateContext,
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path: path,
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name: ast::ident,
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methods: &[@ast::method],
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generics: &ast::Generics,
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id: ast::node_id) {
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let _icx = push_ctxt("impl::trans_impl");
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let tcx = ccx.tcx;
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debug!("trans_impl(path=%s, name=%s, id=%?)",
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path.repr(tcx), name.repr(tcx), id);
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if !generics.ty_params.is_empty() { return; }
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let sub_path = vec::append_one(path, path_name(name));
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for methods.iter().advance |method| {
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if method.generics.ty_params.len() == 0u {
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let llfn = get_item_val(ccx, method.id);
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let path = vec::append_one(/*bad*/copy sub_path,
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path_name(method.ident));
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trans_method(ccx,
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path,
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*method,
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None,
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llfn,
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ast_util::local_def(id));
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}
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}
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}
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/**
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Translates a (possibly monomorphized) method body.
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# Parameters
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- `path`: the path to the method
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- `method`: the AST node for the method
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- `param_substs`: if this is a generic method, the current values for
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type parameters and so forth, else none
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- `llfn`: the LLVM ValueRef for the method
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- `impl_id`: the node ID of the impl this method is inside
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*/
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pub fn trans_method(ccx: @mut CrateContext,
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path: path,
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method: &ast::method,
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param_substs: Option<@param_substs>,
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llfn: ValueRef,
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impl_id: ast::def_id) {
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// figure out how self is being passed
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let self_arg = match method.explicit_self.node {
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ast::sty_static => {
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no_self
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}
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_ => {
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// determine the (monomorphized) type that `self` maps to for
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// this method
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let self_ty = ty::node_id_to_type(ccx.tcx, method.self_id);
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let self_ty = match param_substs {
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None => self_ty,
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Some(@param_substs {tys: ref tys, _}) => {
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ty::subst_tps(ccx.tcx, *tys, None, self_ty)
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}
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};
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debug!("calling trans_fn with self_ty %s",
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self_ty.repr(ccx.tcx));
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match method.explicit_self.node {
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ast::sty_value => {
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impl_owned_self(self_ty)
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}
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_ => {
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impl_self(self_ty)
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}
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}
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}
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};
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// generate the actual code
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trans_fn(ccx,
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path,
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&method.decl,
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&method.body,
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llfn,
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self_arg,
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param_substs,
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method.id,
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Some(impl_id),
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[]);
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}
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pub fn trans_self_arg(bcx: block,
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base: @ast::expr,
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mentry: typeck::method_map_entry) -> Result {
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let _icx = push_ctxt("impl::trans_self_arg");
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let mut temp_cleanups = ~[];
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// Compute the type of self.
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let self_ty = monomorphize_type(bcx, mentry.self_ty);
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let result = trans_arg_expr(bcx,
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self_ty,
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mentry.self_mode,
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base,
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&mut temp_cleanups,
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None,
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DontAutorefArg);
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// FIXME(#3446)---this is wrong, actually. The temp_cleanups
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// should be revoked only after all arguments have been passed.
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for temp_cleanups.iter().advance |c| {
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revoke_clean(bcx, *c)
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}
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return result;
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}
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pub fn trans_method_callee(bcx: block,
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callee_id: ast::node_id,
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this: @ast::expr,
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mentry: typeck::method_map_entry)
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-> Callee {
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let _icx = push_ctxt("impl::trans_method_callee");
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let tcx = bcx.tcx();
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debug!("trans_method_callee(callee_id=%?, this=%s, mentry=%s)",
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callee_id,
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bcx.expr_to_str(this),
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mentry.repr(bcx.tcx()));
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// Replace method_self with method_static here.
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let mut origin = mentry.origin;
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match origin {
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typeck::method_self(trait_id, method_index) => {
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// Get the ID of the impl we're inside.
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let impl_def_id = bcx.fcx.impl_id.get();
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debug!("impl_def_id is %?", impl_def_id);
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// Get the ID of the method we're calling.
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let method_name =
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ty::trait_method(tcx, trait_id, method_index).ident;
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let method_id =
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method_with_name_or_default(bcx.ccx(),
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impl_def_id,
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method_name);
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origin = typeck::method_static(method_id);
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}
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typeck::method_super(trait_id, method_index) => {
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// <self_ty> is the self type for this method call
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let self_ty = node_id_type(bcx, this.id);
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// <impl_id> is the ID of the implementation of
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// trait <trait_id> for type <self_ty>
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let impl_id = ty::get_impl_id(tcx, trait_id, self_ty);
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// Get the supertrait's methods
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let supertrait_method_def_ids = ty::trait_method_def_ids(tcx, trait_id);
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// Make sure to fail with a readable error message if
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// there's some internal error here
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if !(method_index < supertrait_method_def_ids.len()) {
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tcx.sess.bug("trans_method_callee: supertrait method \
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index is out of bounds");
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}
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// Get the method name using the method index in the origin
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let method_name =
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ty::method(tcx, supertrait_method_def_ids[method_index]).ident;
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// Now that we know the impl ID, we can look up the method
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// ID from its name
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origin = typeck::method_static(
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method_with_name_or_default(bcx.ccx(),
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impl_id,
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method_name));
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}
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typeck::method_static(*) | typeck::method_param(*) |
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typeck::method_trait(*) => {}
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}
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debug!("origin=%?", origin);
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match origin {
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typeck::method_static(did) => {
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let callee_fn = callee::trans_fn_ref(bcx, did, callee_id);
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let Result {bcx, val} = trans_self_arg(bcx, this, mentry);
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Callee {
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bcx: bcx,
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data: Method(MethodData {
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llfn: callee_fn.llfn,
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llself: val,
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self_ty: node_id_type(bcx, this.id),
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self_mode: mentry.self_mode,
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})
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}
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}
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typeck::method_param(typeck::method_param {
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trait_id: trait_id,
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method_num: off,
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param_num: p,
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bound_num: b
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}) => {
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match bcx.fcx.param_substs {
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Some(substs) => {
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let vtbl = find_vtable(bcx.tcx(), substs, p, b);
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trans_monomorphized_callee(bcx, callee_id, this, mentry,
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trait_id, off, vtbl)
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}
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// how to get rid of this?
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None => fail!("trans_method_callee: missing param_substs")
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}
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}
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typeck::method_trait(_, off, store) => {
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trans_trait_callee(bcx,
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callee_id,
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off,
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this,
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store,
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mentry.explicit_self)
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}
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typeck::method_self(*) | typeck::method_super(*) => {
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fail!("method_self or method_super should have been handled \
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above")
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}
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}
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}
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pub fn trans_static_method_callee(bcx: block,
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method_id: ast::def_id,
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trait_id: ast::def_id,
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callee_id: ast::node_id)
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-> FnData {
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let _icx = push_ctxt("impl::trans_static_method_callee");
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let ccx = bcx.ccx();
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debug!("trans_static_method_callee(method_id=%?, trait_id=%s, \
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callee_id=%?)",
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method_id,
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ty::item_path_str(bcx.tcx(), trait_id),
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callee_id);
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let _indenter = indenter();
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// When we translate a static fn defined in a trait like:
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//
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// trait<T1...Tn> Trait {
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// fn foo<M1...Mn>(...) {...}
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// }
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//
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// this winds up being translated as something like:
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//
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// fn foo<T1...Tn,self: Trait<T1...Tn>,M1...Mn>(...) {...}
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//
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// So when we see a call to this function foo, we have to figure
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// out which impl the `Trait<T1...Tn>` bound on the type `self` was
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// bound to. Due to the fact that we use a flattened list of
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// impls, one per bound, this means we have to total up the bounds
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// found on the type parametesr T1...Tn to find the index of the
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// one we are interested in.
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let bound_index = {
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let trait_def = ty::lookup_trait_def(bcx.tcx(), trait_id);
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ty::count_traits_and_supertraits(
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bcx.tcx(), *trait_def.generics.type_param_defs)
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};
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let mname = if method_id.crate == ast::local_crate {
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match bcx.tcx().items.get_copy(&method_id.node) {
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ast_map::node_trait_method(trait_method, _, _) => {
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ast_util::trait_method_to_ty_method(trait_method).ident
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}
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_ => fail!("callee is not a trait method")
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}
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} else {
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let path = csearch::get_item_path(bcx.tcx(), method_id);
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match path[path.len()-1] {
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path_name(s) => { s }
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path_mod(_) => { fail!("path doesn't have a name?") }
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}
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};
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debug!("trans_static_method_callee: method_id=%?, callee_id=%?, \
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name=%s", method_id, callee_id, ccx.sess.str_of(mname));
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let vtbls = resolve_vtables_in_fn_ctxt(
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bcx.fcx, ccx.maps.vtable_map.get_copy(&callee_id));
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match vtbls[bound_index] {
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typeck::vtable_static(impl_did, ref rcvr_substs, rcvr_origins) => {
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assert!(rcvr_substs.iter().all(|t| !ty::type_needs_infer(*t)));
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let mth_id = method_with_name_or_default(bcx.ccx(),
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impl_did,
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mname);
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let callee_substs = combine_impl_and_methods_tps(
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bcx, mth_id, impl_did, callee_id, *rcvr_substs);
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let callee_origins = combine_impl_and_methods_origins(
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bcx, mth_id, impl_did, callee_id, rcvr_origins);
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let FnData {llfn: lval} =
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trans_fn_ref_with_vtables(bcx,
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mth_id,
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callee_id,
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callee_substs,
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Some(callee_origins));
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let callee_ty = node_id_type(bcx, callee_id);
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let llty = type_of_fn_from_ty(ccx, callee_ty).ptr_to();
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FnData {llfn: PointerCast(bcx, lval, llty)}
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}
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_ => {
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fail!("vtable_param left in monomorphized \
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function's vtable substs");
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}
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}
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}
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pub fn method_from_methods(ms: &[@ast::method], name: ast::ident)
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-> Option<ast::def_id> {
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ms.iter().find_(|m| m.ident == name).map(|m| ast_util::local_def(m.id))
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}
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pub fn method_with_name_or_default(ccx: @mut CrateContext,
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impl_id: ast::def_id,
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name: ast::ident) -> ast::def_id {
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let imp = ccx.impl_method_cache.find_copy(&(impl_id, name));
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match imp {
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Some(m) => return m,
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None => {}
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}
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// None of this feels like it should be the best way to do this.
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let mut did = if impl_id.crate == ast::local_crate {
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match ccx.tcx.items.get_copy(&impl_id.node) {
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ast_map::node_item(@ast::item {
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node: ast::item_impl(_, _, _, ref ms), _
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}, _) => { method_from_methods(*ms, name) },
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_ => fail!("method_with_name")
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}
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} else {
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csearch::get_impl_method(ccx.sess.cstore, impl_id, name)
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};
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if did.is_none() {
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// Look for a default method
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let pmm = ccx.tcx.provided_methods;
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match pmm.find(&impl_id) {
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Some(pmis) => {
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for pmis.iter().advance |pmi| {
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if pmi.method_info.ident == name {
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debug!("pmi.method_info.did = %?",
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pmi.method_info.did);
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did = Some(pmi.method_info.did);
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}
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}
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}
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None => {}
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}
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}
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let imp = did.expect("could not find method while translating");
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ccx.impl_method_cache.insert((impl_id, name), imp);
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imp
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}
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pub fn method_ty_param_count(ccx: &CrateContext, m_id: ast::def_id,
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i_id: ast::def_id) -> uint {
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debug!("method_ty_param_count: m_id: %?, i_id: %?", m_id, i_id);
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ty::method(ccx.tcx, m_id).generics.type_param_defs.len()
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}
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pub fn trans_monomorphized_callee(bcx: block,
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callee_id: ast::node_id,
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base: @ast::expr,
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mentry: typeck::method_map_entry,
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trait_id: ast::def_id,
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n_method: uint,
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vtbl: typeck::vtable_origin)
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-> Callee {
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let _icx = push_ctxt("impl::trans_monomorphized_callee");
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return match vtbl {
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typeck::vtable_static(impl_did, ref rcvr_substs, rcvr_origins) => {
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let ccx = bcx.ccx();
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let mname = ty::trait_method(ccx.tcx, trait_id, n_method).ident;
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let mth_id = method_with_name_or_default(
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bcx.ccx(), impl_did, mname);
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// obtain the `self` value:
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let Result {bcx, val: llself_val} =
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trans_self_arg(bcx, base, mentry);
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// create a concatenated set of substitutions which includes
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// those from the impl and those from the method:
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let callee_substs = combine_impl_and_methods_tps(
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bcx, mth_id, impl_did, callee_id, *rcvr_substs);
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let callee_origins = combine_impl_and_methods_origins(
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bcx, mth_id, impl_did, callee_id, rcvr_origins);
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// translate the function
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let callee = trans_fn_ref_with_vtables(bcx,
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mth_id,
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callee_id,
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callee_substs,
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Some(callee_origins));
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// create a llvalue that represents the fn ptr
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let fn_ty = node_id_type(bcx, callee_id);
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let llfn_ty = type_of_fn_from_ty(ccx, fn_ty).ptr_to();
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let llfn_val = PointerCast(bcx, callee.llfn, llfn_ty);
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// combine the self environment with the rest
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Callee {
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bcx: bcx,
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data: Method(MethodData {
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llfn: llfn_val,
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llself: llself_val,
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self_ty: node_id_type(bcx, base.id),
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self_mode: mentry.self_mode,
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})
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}
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}
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typeck::vtable_param(*) => {
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fail!("vtable_param left in monomorphized function's vtable substs");
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}
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};
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}
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pub fn combine_impl_and_methods_tps(bcx: block,
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mth_did: ast::def_id,
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impl_did: ast::def_id,
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callee_id: ast::node_id,
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rcvr_substs: &[ty::t])
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-> ~[ty::t] {
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/*!
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*
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* Creates a concatenated set of substitutions which includes
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* those from the impl and those from the method. This are
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* some subtle complications here. Statically, we have a list
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* of type parameters like `[T0, T1, T2, M1, M2, M3]` where
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|
* `Tn` are type parameters that appear on the receiver. For
|
|
* example, if the receiver is a method parameter `A` with a
|
|
* bound like `trait<B,C,D>` then `Tn` would be `[B,C,D]`.
|
|
*
|
|
* The weird part is that the type `A` might now be bound to
|
|
* any other type, such as `foo<X>`. In that case, the vector
|
|
* we want is: `[X, M1, M2, M3]`. Therefore, what we do now is
|
|
* to slice off the method type parameters and append them to
|
|
* the type parameters from the type that the receiver is
|
|
* mapped to. */
|
|
|
|
let ccx = bcx.ccx();
|
|
let n_m_tps = method_ty_param_count(ccx, mth_did, impl_did);
|
|
let node_substs = node_id_type_params(bcx, callee_id);
|
|
debug!("rcvr_substs=%?", rcvr_substs.map(|t| bcx.ty_to_str(*t)));
|
|
let ty_substs
|
|
= vec::append(rcvr_substs.to_owned(),
|
|
vec::tailn(node_substs,
|
|
node_substs.len() - n_m_tps));
|
|
debug!("n_m_tps=%?", n_m_tps);
|
|
debug!("node_substs=%?", node_substs.map(|t| bcx.ty_to_str(*t)));
|
|
debug!("ty_substs=%?", ty_substs.map(|t| bcx.ty_to_str(*t)));
|
|
|
|
return ty_substs;
|
|
}
|
|
|
|
pub fn combine_impl_and_methods_origins(bcx: block,
|
|
mth_did: ast::def_id,
|
|
impl_did: ast::def_id,
|
|
callee_id: ast::node_id,
|
|
rcvr_origins: typeck::vtable_res)
|
|
-> typeck::vtable_res {
|
|
/*!
|
|
*
|
|
* Similar to `combine_impl_and_methods_tps`, but for vtables.
|
|
* This is much messier because of the flattened layout we are
|
|
* currently using (for some reason that I fail to understand).
|
|
* The proper fix is described in #3446.
|
|
*/
|
|
|
|
|
|
// Find the bounds for the method, which are the tail of the
|
|
// bounds found in the item type, as the item type combines the
|
|
// rcvr + method bounds.
|
|
let ccx = bcx.ccx();
|
|
let tcx = bcx.tcx();
|
|
let n_m_tps = method_ty_param_count(ccx, mth_did, impl_did);
|
|
let ty::ty_param_bounds_and_ty {
|
|
generics: r_m_generics,
|
|
_
|
|
} = ty::lookup_item_type(tcx, mth_did);
|
|
let n_r_m_tps = r_m_generics.type_param_defs.len(); // rcvr + method tps
|
|
let m_type_param_defs =
|
|
vec::slice(*r_m_generics.type_param_defs, n_r_m_tps - n_m_tps, n_r_m_tps);
|
|
|
|
// Flatten out to find the number of vtables the method expects.
|
|
let m_vtables = ty::count_traits_and_supertraits(tcx, m_type_param_defs);
|
|
|
|
// Find the vtables we computed at type check time and monomorphize them
|
|
let r_m_origins = match node_vtables(bcx, callee_id) {
|
|
Some(vt) => vt,
|
|
None => @~[]
|
|
};
|
|
|
|
// Extract those that belong to method:
|
|
let m_origins = vec::tailn(*r_m_origins, r_m_origins.len() - m_vtables);
|
|
|
|
// Combine rcvr + method to find the final result:
|
|
@vec::append(/*bad*/copy *rcvr_origins, m_origins)
|
|
}
|
|
|
|
|
|
pub fn trans_trait_callee(bcx: block,
|
|
callee_id: ast::node_id,
|
|
n_method: uint,
|
|
self_expr: @ast::expr,
|
|
store: ty::TraitStore,
|
|
explicit_self: ast::explicit_self_)
|
|
-> Callee {
|
|
//!
|
|
//
|
|
// Create a method callee where the method is coming from a trait
|
|
// instance (e.g., @Trait type). In this case, we must pull the
|
|
// fn pointer out of the vtable that is packaged up with the
|
|
// @/~/&Trait instance. @/~/&Traits are represented as a pair, so we
|
|
// first evaluate the self expression (expected a by-ref result) and then
|
|
// extract the self data and vtable out of the pair.
|
|
|
|
let _icx = push_ctxt("impl::trans_trait_callee");
|
|
let mut bcx = bcx;
|
|
let self_datum = unpack_datum!(bcx,
|
|
expr::trans_to_datum(bcx, self_expr));
|
|
let llpair = self_datum.to_ref_llval(bcx);
|
|
|
|
let llpair = match explicit_self {
|
|
ast::sty_region(*) => Load(bcx, llpair),
|
|
ast::sty_static | ast::sty_value |
|
|
ast::sty_box(_) | ast::sty_uniq(_) => llpair
|
|
};
|
|
|
|
let callee_ty = node_id_type(bcx, callee_id);
|
|
trans_trait_callee_from_llval(bcx,
|
|
callee_ty,
|
|
n_method,
|
|
llpair,
|
|
store,
|
|
explicit_self)
|
|
}
|
|
|
|
pub fn trans_trait_callee_from_llval(bcx: block,
|
|
callee_ty: ty::t,
|
|
n_method: uint,
|
|
llpair: ValueRef,
|
|
store: ty::TraitStore,
|
|
explicit_self: ast::explicit_self_)
|
|
-> Callee {
|
|
//!
|
|
//
|
|
// Same as `trans_trait_callee()` above, except that it is given
|
|
// a by-ref pointer to the @Trait pair.
|
|
|
|
let _icx = push_ctxt("impl::trans_trait_callee");
|
|
let ccx = bcx.ccx();
|
|
let mut bcx = bcx;
|
|
|
|
// Load the vtable from the @Trait pair
|
|
debug!("(translating trait callee) loading vtable from pair %s",
|
|
bcx.val_to_str(llpair));
|
|
let llvtable = Load(bcx,
|
|
PointerCast(bcx,
|
|
GEPi(bcx, llpair,
|
|
[0u, abi::trt_field_vtable]),
|
|
Type::vtable().ptr_to().ptr_to()));
|
|
|
|
// Load the box from the @Trait pair and GEP over the box header if
|
|
// necessary:
|
|
let mut llself;
|
|
debug!("(translating trait callee) loading second index from pair");
|
|
let llbox = Load(bcx, GEPi(bcx, llpair, [0u, abi::trt_field_box]));
|
|
|
|
// Munge `llself` appropriately for the type of `self` in the method.
|
|
let self_mode;
|
|
match explicit_self {
|
|
ast::sty_static => {
|
|
bcx.tcx().sess.bug("shouldn't see static method here");
|
|
}
|
|
ast::sty_value => {
|
|
bcx.tcx().sess.bug("methods with by-value self should not be \
|
|
called on objects");
|
|
}
|
|
ast::sty_region(*) => {
|
|
// As before, we need to pass a pointer to a pointer to the
|
|
// payload.
|
|
match store {
|
|
ty::BoxTraitStore |
|
|
ty::UniqTraitStore => {
|
|
llself = GEPi(bcx, llbox, [0u, abi::box_field_body]);
|
|
}
|
|
ty::RegionTraitStore(_) => {
|
|
llself = llbox;
|
|
}
|
|
}
|
|
|
|
let llscratch = alloca(bcx, val_ty(llself));
|
|
Store(bcx, llself, llscratch);
|
|
llself = llscratch;
|
|
|
|
self_mode = ty::ByRef;
|
|
}
|
|
ast::sty_box(_) => {
|
|
// Bump the reference count on the box.
|
|
debug!("(translating trait callee) callee type is `%s`",
|
|
bcx.ty_to_str(callee_ty));
|
|
bcx = glue::take_ty(bcx, llbox, callee_ty);
|
|
|
|
// Pass a pointer to the box.
|
|
match store {
|
|
ty::BoxTraitStore => llself = llbox,
|
|
_ => bcx.tcx().sess.bug("@self receiver with non-@Trait")
|
|
}
|
|
|
|
let llscratch = alloca(bcx, val_ty(llself));
|
|
Store(bcx, llself, llscratch);
|
|
llself = llscratch;
|
|
|
|
self_mode = ty::ByRef;
|
|
}
|
|
ast::sty_uniq(_) => {
|
|
// Pass the unique pointer.
|
|
match store {
|
|
ty::UniqTraitStore => llself = llbox,
|
|
_ => bcx.tcx().sess.bug("~self receiver with non-~Trait")
|
|
}
|
|
|
|
let llscratch = alloca(bcx, val_ty(llself));
|
|
Store(bcx, llself, llscratch);
|
|
llself = llscratch;
|
|
|
|
self_mode = ty::ByRef;
|
|
}
|
|
}
|
|
|
|
// Load the function from the vtable and cast it to the expected type.
|
|
debug!("(translating trait callee) loading method");
|
|
let llcallee_ty = type_of_fn_from_ty(ccx, callee_ty);
|
|
|
|
// Plus one in order to skip past the type descriptor.
|
|
let mptr = Load(bcx, GEPi(bcx, llvtable, [0u, n_method + 1]));
|
|
|
|
let mptr = PointerCast(bcx, mptr, llcallee_ty.ptr_to());
|
|
|
|
return Callee {
|
|
bcx: bcx,
|
|
data: Method(MethodData {
|
|
llfn: mptr,
|
|
llself: llself,
|
|
self_ty: ty::mk_opaque_box(bcx.tcx()),
|
|
self_mode: self_mode,
|
|
/* XXX: Some(llbox) */
|
|
})
|
|
};
|
|
}
|
|
|
|
pub fn vtable_id(ccx: @mut CrateContext,
|
|
origin: &typeck::vtable_origin)
|
|
-> mono_id {
|
|
match origin {
|
|
&typeck::vtable_static(impl_id, ref substs, sub_vtables) => {
|
|
monomorphize::make_mono_id(
|
|
ccx,
|
|
impl_id,
|
|
*substs,
|
|
if sub_vtables.is_empty() {
|
|
None
|
|
} else {
|
|
Some(sub_vtables)
|
|
},
|
|
None,
|
|
None)
|
|
}
|
|
|
|
// can't this be checked at the callee?
|
|
_ => fail!("vtable_id")
|
|
}
|
|
}
|
|
|
|
/// Creates a returns a dynamic vtable for the given type and vtable origin.
|
|
/// This is used only for objects.
|
|
pub fn get_vtable(bcx: block,
|
|
self_ty: ty::t,
|
|
origin: typeck::vtable_origin)
|
|
-> ValueRef {
|
|
let hash_id = vtable_id(bcx.ccx(), &origin);
|
|
match bcx.ccx().vtables.find(&hash_id) {
|
|
Some(&val) => val,
|
|
None => {
|
|
match origin {
|
|
typeck::vtable_static(id, substs, sub_vtables) => {
|
|
make_impl_vtable(bcx, id, self_ty, substs, sub_vtables)
|
|
}
|
|
_ => fail!("get_vtable: expected a static origin"),
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Helper function to declare and initialize the vtable.
|
|
pub fn make_vtable(ccx: @mut CrateContext,
|
|
tydesc: @mut tydesc_info,
|
|
ptrs: &[ValueRef])
|
|
-> ValueRef {
|
|
unsafe {
|
|
let _icx = push_ctxt("impl::make_vtable");
|
|
|
|
let mut components = ~[ tydesc.tydesc ];
|
|
for ptrs.iter().advance |&ptr| {
|
|
components.push(ptr)
|
|
}
|
|
|
|
let tbl = C_struct(components);
|
|
let vtable = ccx.sess.str_of((ccx.names)("vtable"));
|
|
let vt_gvar = do str::as_c_str(vtable) |buf| {
|
|
llvm::LLVMAddGlobal(ccx.llmod, val_ty(tbl).to_ref(), buf)
|
|
};
|
|
llvm::LLVMSetInitializer(vt_gvar, tbl);
|
|
llvm::LLVMSetGlobalConstant(vt_gvar, lib::llvm::True);
|
|
lib::llvm::SetLinkage(vt_gvar, lib::llvm::InternalLinkage);
|
|
vt_gvar
|
|
}
|
|
}
|
|
|
|
/// Generates a dynamic vtable for objects.
|
|
pub fn make_impl_vtable(bcx: block,
|
|
impl_id: ast::def_id,
|
|
self_ty: ty::t,
|
|
substs: ~[ty::t],
|
|
vtables: typeck::vtable_res)
|
|
-> ValueRef {
|
|
let ccx = bcx.ccx();
|
|
let _icx = push_ctxt("impl::make_impl_vtable");
|
|
let tcx = ccx.tcx;
|
|
|
|
let trt_id = match ty::impl_trait_ref(tcx, impl_id) {
|
|
Some(t_id) => t_id.def_id,
|
|
None => ccx.sess.bug("make_impl_vtable: don't know how to \
|
|
make a vtable for a type impl!")
|
|
};
|
|
|
|
let trait_method_def_ids = ty::trait_method_def_ids(tcx, trt_id);
|
|
let methods = do trait_method_def_ids.map |method_def_id| {
|
|
let im = ty::method(tcx, *method_def_id);
|
|
let fty = ty::subst_tps(tcx,
|
|
substs,
|
|
None,
|
|
ty::mk_bare_fn(tcx, copy im.fty));
|
|
if im.generics.has_type_params() || ty::type_has_self(fty) {
|
|
debug!("(making impl vtable) method has self or type params: %s",
|
|
tcx.sess.str_of(im.ident));
|
|
C_null(Type::nil().ptr_to())
|
|
} else {
|
|
debug!("(making impl vtable) adding method to vtable: %s",
|
|
tcx.sess.str_of(im.ident));
|
|
let m_id = method_with_name_or_default(ccx, impl_id, im.ident);
|
|
|
|
trans_fn_ref_with_vtables(bcx, m_id, 0,
|
|
substs, Some(vtables)).llfn
|
|
}
|
|
};
|
|
|
|
// Generate a type descriptor for the vtable.
|
|
let tydesc = get_tydesc(ccx, self_ty);
|
|
glue::lazily_emit_all_tydesc_glue(ccx, tydesc);
|
|
|
|
make_vtable(ccx, tydesc, methods)
|
|
}
|
|
|
|
pub fn trans_trait_cast(bcx: block,
|
|
val: @ast::expr,
|
|
id: ast::node_id,
|
|
dest: expr::Dest,
|
|
_store: ty::TraitStore)
|
|
-> block {
|
|
let mut bcx = bcx;
|
|
let _icx = push_ctxt("impl::trans_cast");
|
|
|
|
let lldest = match dest {
|
|
Ignore => {
|
|
return expr::trans_into(bcx, val, Ignore);
|
|
}
|
|
SaveIn(dest) => dest
|
|
};
|
|
|
|
let ccx = bcx.ccx();
|
|
let v_ty = expr_ty(bcx, val);
|
|
|
|
let mut llboxdest = GEPi(bcx, lldest, [0u, abi::trt_field_box]);
|
|
// Just store the pointer into the pair. (Region/borrowed
|
|
// and boxed trait objects are represented as pairs, and
|
|
// have no type descriptor field.)
|
|
llboxdest = PointerCast(bcx,
|
|
llboxdest,
|
|
type_of(bcx.ccx(), v_ty).ptr_to());
|
|
bcx = expr::trans_into(bcx, val, SaveIn(llboxdest));
|
|
|
|
// Store the vtable into the pair or triple.
|
|
let orig = /*bad*/copy ccx.maps.vtable_map.get(&id)[0];
|
|
let orig = resolve_vtable_in_fn_ctxt(bcx.fcx, orig);
|
|
let vtable = get_vtable(bcx, v_ty, orig);
|
|
Store(bcx, vtable, PointerCast(bcx,
|
|
GEPi(bcx, lldest, [0u, abi::trt_field_vtable]),
|
|
val_ty(vtable).ptr_to()));
|
|
|
|
bcx
|
|
}
|