1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
4 //
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
10
11 use lib::llvm::{AvailableExternallyLinkage, SetLinkage};
12 use metadata::csearch;
13 use middle::astencode;
14 use middle::trans::base::{push_ctxt, trans_item, get_item_val, trans_fn};
15 use middle::trans::common::*;
16 use middle::ty;
17
18 use syntax::ast;
19 use syntax::ast_util::local_def;
20 use syntax::attr;
21
22 pub fn maybe_instantiate_inline(ccx: &CrateContext, fn_id: ast::DefId)
23 -> ast::DefId {
24 let _icx = push_ctxt("maybe_instantiate_inline");
25 match ccx.external.borrow().find(&fn_id) {
26 Some(&Some(node_id)) => {
27 // Already inline
28 debug!("maybe_instantiate_inline({}): already inline as node id {}",
29 ty::item_path_str(ccx.tcx(), fn_id), node_id);
30 return local_def(node_id);
31 }
32 Some(&None) => {
33 return fn_id; // Not inlinable
34 }
35 None => {
36 // Not seen yet
37 }
38 }
39
40 let csearch_result =
41 csearch::maybe_get_item_ast(
42 ccx.tcx(), fn_id,
43 |a,b,c,d| astencode::decode_inlined_item(a, b, c, d));
44 return match csearch_result {
45 csearch::not_found => {
46 ccx.external.borrow_mut().insert(fn_id, None);
47 fn_id
48 }
49 csearch::found(ast::IIItem(item)) => {
50 ccx.external.borrow_mut().insert(fn_id, Some(item.id));
51 ccx.external_srcs.borrow_mut().insert(item.id, fn_id);
52
53 ccx.stats.n_inlines.set(ccx.stats.n_inlines.get() + 1);
54 trans_item(ccx, item);
55
56 // We're bringing an external global into this crate, but we don't
57 // want to create two copies of the global. If we do this, then if
58 // you take the address of the global in two separate crates you get
59 // two different addresses. This is bad for things like conditions,
60 // but it could possibly have other adverse side effects. We still
61 // want to achieve the optimizations related to this global,
62 // however, so we use the available_externally linkage which llvm
63 // provides
64 match item.node {
65 ast::ItemStatic(..) => {
66 let g = get_item_val(ccx, item.id);
67 // see the comment in get_item_val() as to why this check is
68 // performed here.
69 if !attr::contains_name(item.attrs.as_slice(),
70 "address_insignificant") {
71 SetLinkage(g, AvailableExternallyLinkage);
72 }
73 }
74 _ => {}
75 }
76
77 local_def(item.id)
78 }
79 csearch::found(ast::IIForeign(item)) => {
80 ccx.external.borrow_mut().insert(fn_id, Some(item.id));
81 ccx.external_srcs.borrow_mut().insert(item.id, fn_id);
82 local_def(item.id)
83 }
84 csearch::found_parent(parent_id, ast::IIItem(item)) => {
85 ccx.external.borrow_mut().insert(parent_id, Some(item.id));
86 ccx.external_srcs.borrow_mut().insert(item.id, parent_id);
87
88 let mut my_id = 0;
89 match item.node {
90 ast::ItemEnum(_, _) => {
91 let vs_here = ty::enum_variants(ccx.tcx(), local_def(item.id));
92 let vs_there = ty::enum_variants(ccx.tcx(), parent_id);
93 for (here, there) in vs_here.iter().zip(vs_there.iter()) {
94 if there.id == fn_id { my_id = here.id.node; }
95 ccx.external.borrow_mut().insert(there.id, Some(here.id.node));
96 }
97 }
98 ast::ItemStruct(ref struct_def, _) => {
99 match struct_def.ctor_id {
100 None => {}
101 Some(ctor_id) => {
102 ccx.external.borrow_mut().insert(fn_id, Some(ctor_id));
103 my_id = ctor_id;
104 }
105 }
106 }
107 _ => ccx.sess().bug("maybe_instantiate_inline: item has a \
108 non-enum, non-struct parent")
109 }
110 trans_item(ccx, item);
111 local_def(my_id)
112 }
113 csearch::found_parent(_, _) => {
114 ccx.sess().bug("maybe_get_item_ast returned a found_parent \
115 with a non-item parent");
116 }
117 csearch::found(ast::IIMethod(impl_did, is_provided, mth)) => {
118 ccx.external.borrow_mut().insert(fn_id, Some(mth.id));
119 ccx.external_srcs.borrow_mut().insert(mth.id, fn_id);
120
121 ccx.stats.n_inlines.set(ccx.stats.n_inlines.get() + 1);
122
123 // If this is a default method, we can't look up the
124 // impl type. But we aren't going to translate anyways, so don't.
125 if is_provided { return local_def(mth.id); }
126
127 let impl_tpt = ty::lookup_item_type(ccx.tcx(), impl_did);
128 let num_type_params =
129 impl_tpt.generics.type_param_defs().len() +
130 mth.generics.ty_params.len();
131
132 if num_type_params == 0 {
133 let llfn = get_item_val(ccx, mth.id);
134 trans_fn(ccx, mth.decl, mth.body, llfn, None, mth.id, []);
135 }
136 local_def(mth.id)
137 }
138 };
139 }