453 lines
17 KiB
Rust
453 lines
17 KiB
Rust
// Copyright 2012-2014 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 arena::TypedArena;
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use back::link::{self, mangle_internal_name_by_path_and_seq};
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use llvm::{ValueRef, get_param};
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use middle::mem_categorization::Typer;
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use trans::adt;
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use trans::attributes;
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use trans::base::*;
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use trans::build::*;
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use trans::callee::{self, ArgVals, Callee, TraitItem, MethodData};
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use trans::cleanup::{CleanupMethods, CustomScope, ScopeId};
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use trans::common::*;
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use trans::datum::{self, Datum, rvalue_scratch_datum, Rvalue, ByValue};
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use trans::debuginfo::{self, DebugLoc};
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use trans::declare;
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use trans::expr;
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use trans::monomorphize::{self, MonoId};
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use trans::type_of::*;
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use middle::ty::{self, ClosureTyper};
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use middle::subst::Substs;
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use session::config::FullDebugInfo;
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use util::ppaux::Repr;
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use syntax::abi::RustCall;
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use syntax::ast;
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use syntax::ast_util;
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fn load_closure_environment<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
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arg_scope_id: ScopeId,
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freevars: &[ty::Freevar])
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-> Block<'blk, 'tcx>
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{
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let _icx = push_ctxt("closure::load_closure_environment");
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// Special case for small by-value selfs.
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let closure_id = ast_util::local_def(bcx.fcx.id);
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let self_type = self_type_for_closure(bcx.ccx(), closure_id,
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node_id_type(bcx, closure_id.node));
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let kind = kind_for_closure(bcx.ccx(), closure_id);
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let llenv = if kind == ty::FnOnceClosureKind &&
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!arg_is_indirect(bcx.ccx(), self_type) {
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let datum = rvalue_scratch_datum(bcx,
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self_type,
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"closure_env");
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store_ty(bcx, bcx.fcx.llenv.unwrap(), datum.val, self_type);
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datum.val
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} else {
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bcx.fcx.llenv.unwrap()
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};
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// Store the pointer to closure data in an alloca for debug info because that's what the
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// llvm.dbg.declare intrinsic expects
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let env_pointer_alloca = if bcx.sess().opts.debuginfo == FullDebugInfo {
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let alloc = alloca(bcx, val_ty(llenv), "__debuginfo_env_ptr");
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Store(bcx, llenv, alloc);
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Some(alloc)
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} else {
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None
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};
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for (i, freevar) in freevars.iter().enumerate() {
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let upvar_id = ty::UpvarId { var_id: freevar.def.local_node_id(),
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closure_expr_id: closure_id.node };
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let upvar_capture = bcx.tcx().upvar_capture(upvar_id).unwrap();
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let mut upvar_ptr = GEPi(bcx, llenv, &[0, i]);
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let captured_by_ref = match upvar_capture {
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ty::UpvarCapture::ByValue => false,
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ty::UpvarCapture::ByRef(..) => {
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upvar_ptr = Load(bcx, upvar_ptr);
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true
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}
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};
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let def_id = freevar.def.def_id();
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bcx.fcx.llupvars.borrow_mut().insert(def_id.node, upvar_ptr);
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if kind == ty::FnOnceClosureKind && !captured_by_ref {
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bcx.fcx.schedule_drop_mem(arg_scope_id,
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upvar_ptr,
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node_id_type(bcx, def_id.node))
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}
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if let Some(env_pointer_alloca) = env_pointer_alloca {
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debuginfo::create_captured_var_metadata(
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bcx,
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def_id.node,
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env_pointer_alloca,
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i,
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captured_by_ref,
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freevar.span);
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}
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}
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bcx
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}
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pub enum ClosureEnv<'a> {
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NotClosure,
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Closure(&'a [ty::Freevar]),
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}
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impl<'a> ClosureEnv<'a> {
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pub fn load<'blk,'tcx>(self, bcx: Block<'blk, 'tcx>, arg_scope: ScopeId)
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-> Block<'blk, 'tcx>
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{
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match self {
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ClosureEnv::NotClosure => bcx,
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ClosureEnv::Closure(freevars) => {
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if freevars.is_empty() {
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bcx
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} else {
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load_closure_environment(bcx, arg_scope, freevars)
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}
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}
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}
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}
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}
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/// Returns the LLVM function declaration for a closure, creating it if
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/// necessary. If the ID does not correspond to a closure ID, returns None.
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pub fn get_or_create_declaration_if_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
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closure_id: ast::DefId,
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substs: &Substs<'tcx>)
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-> Option<Datum<'tcx, Rvalue>> {
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if !ccx.tcx().closure_kinds.borrow().contains_key(&closure_id) {
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// Not a closure.
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return None
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}
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let function_type = ty::node_id_to_type(ccx.tcx(), closure_id.node);
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let function_type = monomorphize::apply_param_substs(ccx.tcx(), substs, &function_type);
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// Normalize type so differences in regions and typedefs don't cause
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// duplicate declarations
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let function_type = erase_regions(ccx.tcx(), &function_type);
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let params = match function_type.sty {
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ty::ty_closure(_, substs) => &substs.types,
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_ => unreachable!()
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};
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let mono_id = MonoId {
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def: closure_id,
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params: params
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};
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match ccx.closure_vals().borrow().get(&mono_id) {
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Some(&llfn) => {
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debug!("get_or_create_declaration_if_closure(): found closure");
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return Some(Datum::new(llfn, function_type, Rvalue::new(ByValue)))
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}
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None => {}
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}
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let symbol = ccx.tcx().map.with_path(closure_id.node, |path| {
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mangle_internal_name_by_path_and_seq(path, "closure")
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});
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// Currently there’s only a single user of get_or_create_declaration_if_closure and it
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// unconditionally defines the function, therefore we use define_* here.
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let llfn = declare::define_internal_rust_fn(ccx, &symbol[..], function_type).unwrap_or_else(||{
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ccx.sess().bug(&format!("symbol `{}` already defined", symbol));
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});
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// set an inline hint for all closures
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attributes::inline(llfn, attributes::InlineAttr::Hint);
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debug!("get_or_create_declaration_if_closure(): inserting new \
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closure {:?} (type {})",
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mono_id,
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ccx.tn().type_to_string(val_ty(llfn)));
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ccx.closure_vals().borrow_mut().insert(mono_id, llfn);
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Some(Datum::new(llfn, function_type, Rvalue::new(ByValue)))
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}
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pub enum Dest<'a, 'tcx: 'a> {
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SaveIn(Block<'a, 'tcx>, ValueRef),
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Ignore(&'a CrateContext<'a, 'tcx>)
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}
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pub fn trans_closure_expr<'a, 'tcx>(dest: Dest<'a, 'tcx>,
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decl: &ast::FnDecl,
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body: &ast::Block,
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id: ast::NodeId,
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param_substs: &'tcx Substs<'tcx>)
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-> Option<Block<'a, 'tcx>>
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{
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let ccx = match dest {
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Dest::SaveIn(bcx, _) => bcx.ccx(),
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Dest::Ignore(ccx) => ccx
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};
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let tcx = ccx.tcx();
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let _icx = push_ctxt("closure::trans_closure");
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debug!("trans_closure()");
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let closure_id = ast_util::local_def(id);
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let llfn = get_or_create_declaration_if_closure(
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ccx,
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closure_id,
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param_substs).unwrap();
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// Get the type of this closure. Use the current `param_substs` as
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// the closure substitutions. This makes sense because the closure
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// takes the same set of type arguments as the enclosing fn, and
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// this function (`trans_closure`) is invoked at the point
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// of the closure expression.
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let typer = NormalizingClosureTyper::new(tcx);
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let function_type = typer.closure_type(closure_id, param_substs);
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let freevars: Vec<ty::Freevar> =
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ty::with_freevars(tcx, id, |fv| fv.iter().cloned().collect());
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let sig = ty::erase_late_bound_regions(tcx, &function_type.sig);
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trans_closure(ccx,
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decl,
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body,
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llfn.val,
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param_substs,
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id,
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&[],
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sig.output,
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function_type.abi,
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ClosureEnv::Closure(&freevars[..]));
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// Don't hoist this to the top of the function. It's perfectly legitimate
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// to have a zero-size closure (in which case dest will be `Ignore`) and
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// we must still generate the closure body.
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let (mut bcx, dest_addr) = match dest {
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Dest::SaveIn(bcx, p) => (bcx, p),
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Dest::Ignore(_) => {
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debug!("trans_closure() ignoring result");
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return None;
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}
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};
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let repr = adt::represent_type(ccx, node_id_type(bcx, id));
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// Create the closure.
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for (i, freevar) in freevars.iter().enumerate() {
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let datum = expr::trans_local_var(bcx, freevar.def);
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let upvar_slot_dest = adt::trans_field_ptr(bcx, &*repr, dest_addr, 0, i);
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let upvar_id = ty::UpvarId { var_id: freevar.def.local_node_id(),
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closure_expr_id: id };
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match tcx.upvar_capture(upvar_id).unwrap() {
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ty::UpvarCapture::ByValue => {
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bcx = datum.store_to(bcx, upvar_slot_dest);
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}
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ty::UpvarCapture::ByRef(..) => {
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Store(bcx, datum.to_llref(), upvar_slot_dest);
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}
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}
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}
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adt::trans_set_discr(bcx, &*repr, dest_addr, 0);
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Some(bcx)
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}
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pub fn trans_closure_method<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
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closure_def_id: ast::DefId,
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substs: Substs<'tcx>,
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node: ExprOrMethodCall,
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param_substs: &'tcx Substs<'tcx>,
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trait_closure_kind: ty::ClosureKind)
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-> ValueRef
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{
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// The substitutions should have no type parameters remaining
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// after passing through fulfill_obligation
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let llfn = callee::trans_fn_ref_with_substs(ccx,
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closure_def_id,
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node,
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param_substs,
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substs.clone()).val;
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// If the closure is a Fn closure, but a FnOnce is needed (etc),
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// then adapt the self type
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let closure_kind = ccx.tcx().closure_kind(closure_def_id);
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trans_closure_adapter_shim(ccx,
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closure_def_id,
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substs,
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closure_kind,
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trait_closure_kind,
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llfn)
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}
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fn trans_closure_adapter_shim<'a, 'tcx>(
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ccx: &'a CrateContext<'a, 'tcx>,
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closure_def_id: ast::DefId,
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substs: Substs<'tcx>,
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llfn_closure_kind: ty::ClosureKind,
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trait_closure_kind: ty::ClosureKind,
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llfn: ValueRef)
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-> ValueRef
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{
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let _icx = push_ctxt("trans_closure_adapter_shim");
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let tcx = ccx.tcx();
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debug!("trans_closure_adapter_shim(llfn_closure_kind={:?}, \
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trait_closure_kind={:?}, \
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llfn={})",
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llfn_closure_kind,
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trait_closure_kind,
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ccx.tn().val_to_string(llfn));
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match (llfn_closure_kind, trait_closure_kind) {
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(ty::FnClosureKind, ty::FnClosureKind) |
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(ty::FnMutClosureKind, ty::FnMutClosureKind) |
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(ty::FnOnceClosureKind, ty::FnOnceClosureKind) => {
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// No adapter needed.
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llfn
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}
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(ty::FnClosureKind, ty::FnMutClosureKind) => {
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// The closure fn `llfn` is a `fn(&self, ...)`. We want a
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// `fn(&mut self, ...)`. In fact, at trans time, these are
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// basically the same thing, so we can just return llfn.
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llfn
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}
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(ty::FnClosureKind, ty::FnOnceClosureKind) |
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(ty::FnMutClosureKind, ty::FnOnceClosureKind) => {
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// The closure fn `llfn` is a `fn(&self, ...)` or `fn(&mut
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// self, ...)`. We want a `fn(self, ...)`. We can produce
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// this by doing something like:
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//
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// fn call_once(self, ...) { call_mut(&self, ...) }
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// fn call_once(mut self, ...) { call_mut(&mut self, ...) }
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//
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// These are both the same at trans time.
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trans_fn_once_adapter_shim(ccx, closure_def_id, substs, llfn)
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}
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_ => {
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tcx.sess.bug(&format!("trans_closure_adapter_shim: cannot convert {:?} to {:?}",
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llfn_closure_kind,
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trait_closure_kind));
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}
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}
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}
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fn trans_fn_once_adapter_shim<'a, 'tcx>(
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ccx: &'a CrateContext<'a, 'tcx>,
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closure_def_id: ast::DefId,
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substs: Substs<'tcx>,
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llreffn: ValueRef)
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-> ValueRef
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{
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debug!("trans_fn_once_adapter_shim(closure_def_id={}, substs={}, llreffn={})",
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closure_def_id.repr(ccx.tcx()),
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substs.repr(ccx.tcx()),
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ccx.tn().val_to_string(llreffn));
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let tcx = ccx.tcx();
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let typer = NormalizingClosureTyper::new(tcx);
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// Find a version of the closure type. Substitute static for the
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// region since it doesn't really matter.
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let substs = tcx.mk_substs(substs);
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let closure_ty = ty::mk_closure(tcx, closure_def_id, substs);
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let ref_closure_ty = ty::mk_imm_rptr(tcx, tcx.mk_region(ty::ReStatic), closure_ty);
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// Make a version with the type of by-ref closure.
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let ty::ClosureTy { unsafety, abi, mut sig } = typer.closure_type(closure_def_id, substs);
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sig.0.inputs.insert(0, ref_closure_ty); // sig has no self type as of yet
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let llref_bare_fn_ty = tcx.mk_bare_fn(ty::BareFnTy { unsafety: unsafety,
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abi: abi,
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sig: sig.clone() });
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let llref_fn_ty = ty::mk_bare_fn(tcx, None, llref_bare_fn_ty);
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debug!("trans_fn_once_adapter_shim: llref_fn_ty={}",
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llref_fn_ty.repr(tcx));
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// Make a version of the closure type with the same arguments, but
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// with argument #0 being by value.
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assert_eq!(abi, RustCall);
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sig.0.inputs[0] = closure_ty;
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let llonce_bare_fn_ty = tcx.mk_bare_fn(ty::BareFnTy { unsafety: unsafety,
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abi: abi,
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sig: sig });
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let llonce_fn_ty = ty::mk_bare_fn(tcx, None, llonce_bare_fn_ty);
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// Create the by-value helper.
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let function_name = link::mangle_internal_name_by_type_and_seq(ccx, llonce_fn_ty, "once_shim");
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let lloncefn = declare::define_internal_rust_fn(ccx, &function_name[..], llonce_fn_ty)
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.unwrap_or_else(||{
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ccx.sess().bug(&format!("symbol `{}` already defined", function_name));
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});
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let sig = ty::erase_late_bound_regions(tcx, &llonce_bare_fn_ty.sig);
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let (block_arena, fcx): (TypedArena<_>, FunctionContext);
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block_arena = TypedArena::new();
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fcx = new_fn_ctxt(ccx,
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lloncefn,
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ast::DUMMY_NODE_ID,
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false,
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sig.output,
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substs,
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None,
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&block_arena);
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let mut bcx = init_function(&fcx, false, sig.output);
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// the first argument (`self`) will be the (by value) closure env.
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let self_scope = fcx.push_custom_cleanup_scope();
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let self_scope_id = CustomScope(self_scope);
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let rvalue_mode = datum::appropriate_rvalue_mode(ccx, closure_ty);
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let llself = get_param(lloncefn, fcx.arg_pos(0) as u32);
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let env_datum = Datum::new(llself, closure_ty, Rvalue::new(rvalue_mode));
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let env_datum = unpack_datum!(bcx,
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env_datum.to_lvalue_datum_in_scope(bcx, "self",
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self_scope_id));
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debug!("trans_fn_once_adapter_shim: env_datum={}",
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bcx.val_to_string(env_datum.val));
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// the remaining arguments will be packed up in a tuple.
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let input_tys = match sig.inputs[1].sty {
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ty::ty_tup(ref tys) => &**tys,
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_ => bcx.sess().bug(&format!("trans_fn_once_adapter_shim: not rust-call! \
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closure_def_id={}",
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closure_def_id.repr(tcx)))
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};
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let llargs: Vec<_> =
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input_tys.iter()
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.enumerate()
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.map(|(i, _)| get_param(lloncefn, fcx.arg_pos(i+1) as u32))
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.collect();
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let dest =
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fcx.llretslotptr.get().map(
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|_| expr::SaveIn(fcx.get_ret_slot(bcx, sig.output, "ret_slot")));
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let callee_data = TraitItem(MethodData { llfn: llreffn,
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llself: env_datum.val });
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bcx = callee::trans_call_inner(bcx,
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DebugLoc::None,
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llref_fn_ty,
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|bcx, _| Callee { bcx: bcx, data: callee_data },
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ArgVals(&llargs),
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dest).bcx;
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fcx.pop_custom_cleanup_scope(self_scope);
|
||
|
||
finish_fn(&fcx, bcx, sig.output, DebugLoc::None);
|
||
|
||
lloncefn
|
||
}
|