rustc: Implement foreign constants.

This is needed for a lot of Apple libraries, as Apple tends to put a lot of
globals in dynamic libraries.

Author: pcwalton

src/libsyntax/ast.rs

@@ -830,6 +830,7 @@ type foreign_item =
 #[auto_serialize]
 enum foreign_item_ {
     foreign_item_fn(fn_decl, purity, ~[ty_param]),
+    foreign_item_const(@ty)
 }
 
 // The data we save and restore about an inlined item or method.  This is not

src/libsyntax/fold.rs

@@ -196,6 +196,9 @@ fn noop_fold_foreign_item(&&ni: @foreign_item, fld: ast_fold)
                                   purity,
                                   fold_ty_params(typms, fld))
                 }
+                foreign_item_const(t) => {
+                  foreign_item_const(fld.fold_ty(t))
+                }
               },
           id: fld.new_id(ni.id),
           span: fld.new_span(ni.span)};

src/libsyntax/parse/parser.rs

@@ -32,32 +32,32 @@ import ast::{_mod, add, alt_check, alt_exhaustive, arg, arm, attribute,
              expr_move, expr_path, expr_rec, expr_repeat, expr_ret, expr_swap,
              expr_struct, expr_tup, expr_unary, expr_unary_move, expr_vec,
              expr_vstore, expr_while, extern_fn, field, fn_decl, foreign_item,
-             foreign_item_fn, foreign_mod, ident, impure_fn, infer, inherited,
-             init_assign, init_move, initializer, item, item_,
-             item_class, item_const, item_enum, item_fn, item_foreign_mod,
-             item_impl, item_mac, item_mod, item_trait, item_ty, lit, lit_,
-             lit_bool, lit_float, lit_int, lit_int_unsuffixed, lit_nil,
-             lit_str, lit_uint, local, m_const, m_imm, m_mutbl, mac_, mac_aq,
-             mac_ellipsis, mac_invoc, mac_invoc_tt, mac_var, matcher,
-             match_nonterminal, match_seq, match_tok, method, mode, mt, mul,
-             mutability, named_field, neg, noreturn, not, pat, pat_box,
-             pat_enum, pat_ident, pat_lit, pat_range, pat_rec, pat_struct,
-             pat_tup, pat_uniq, pat_wild, path, private, proto, proto_bare,
-             proto_block, proto_box, proto_uniq, provided, public, pure_fn,
-             purity, re_anon, re_named, region, rem, required, ret_style,
-             return_val, self_ty, shl, shr, stmt, stmt_decl, stmt_expr,
-             stmt_semi, struct_def, struct_field, struct_variant_kind,
-             subtract, sty_box, sty_by_ref, sty_region, sty_static, sty_uniq,
-             sty_value, token_tree, trait_method, trait_ref, tt_delim, tt_seq,
-             tt_tok, tt_nonterminal, ty, ty_, ty_bot, ty_box, ty_field, ty_fn,
-             ty_infer, ty_mac, ty_method, ty_nil, ty_param, ty_param_bound,
-             ty_path, ty_ptr, ty_rec, ty_rptr, ty_tup, ty_u32, ty_uniq,
-             ty_vec, ty_fixed_length, tuple_variant_kind, unchecked_blk, uniq,
-             unnamed_field, unsafe_blk, unsafe_fn, variant, view_item,
-             view_item_, view_item_export, view_item_import, view_item_use,
-             view_path, view_path_glob, view_path_list, view_path_simple,
-             visibility, vstore, vstore_box, vstore_fixed, vstore_slice,
-             vstore_uniq};
+             foreign_item_const, foreign_item_fn, foreign_mod, ident,
+             impure_fn, infer, inherited, init_assign, init_move, initializer,
+             item, item_, item_class, item_const, item_enum, item_fn,
+             item_foreign_mod, item_impl, item_mac, item_mod, item_trait,
+             item_ty, lit, lit_, lit_bool, lit_float, lit_int,
+             lit_int_unsuffixed, lit_nil, lit_str, lit_uint, local, m_const,
+             m_imm, m_mutbl, mac_, mac_aq, mac_ellipsis, mac_invoc,
+             mac_invoc_tt, mac_var, matcher, match_nonterminal, match_seq,
+             match_tok, method, mode, mt, mul, mutability, named_field, neg,
+             noreturn, not, pat, pat_box, pat_enum, pat_ident, pat_lit,
+             pat_range, pat_rec, pat_struct, pat_tup, pat_uniq, pat_wild,
+             path, private, proto, proto_bare, proto_block, proto_box,
+             proto_uniq, provided, public, pure_fn, purity, re_anon, re_named,
+             region, rem, required, ret_style, return_val, self_ty, shl, shr,
+             stmt, stmt_decl, stmt_expr, stmt_semi, struct_def, struct_field,
+             struct_variant_kind, subtract, sty_box, sty_by_ref, sty_region,
+             sty_static, sty_uniq, sty_value, token_tree, trait_method,
+             trait_ref, tt_delim, tt_seq, tt_tok, tt_nonterminal, ty, ty_,
+             ty_bot, ty_box, ty_field, ty_fn, ty_infer, ty_mac, ty_method,
+             ty_nil, ty_param, ty_param_bound, ty_path, ty_ptr, ty_rec,
+             ty_rptr, ty_tup, ty_u32, ty_uniq, ty_vec, ty_fixed_length,
+             tuple_variant_kind, unchecked_blk, uniq, unnamed_field,
+             unsafe_blk, unsafe_fn, variant, view_item, view_item_,
+             view_item_export, view_item_import, view_item_use, view_path,
+             view_path_glob, view_path_list, view_path_simple, visibility,
+             vstore, vstore_box, vstore_fixed, vstore_slice, vstore_uniq};
 
 export file_type;
 export parser;
@@ -2843,6 +2843,21 @@ struct parser {
                  span: mk_sp(lo, hi)};
     }
 
+    fn parse_item_foreign_const(+attrs: ~[attribute]) -> @foreign_item {
+        let lo = self.span.lo;
+        self.expect_keyword(~"const");
+        let ident = self.parse_ident();
+        self.expect(token::COLON);
+        let ty = self.parse_ty(false);
+        let hi = self.span.hi;
+        self.expect(token::SEMI);
+        return @{ident: ident,
+                 attrs: attrs,
+                 node: foreign_item_const(move ty),
+                 id: self.get_id(),
+                 span: mk_sp(lo, hi)};
+    }
+
     fn parse_fn_purity() -> purity {
         if self.eat_keyword(~"fn") { impure_fn }
         else if self.eat_keyword(~"pure") {
@@ -2855,9 +2870,12 @@ struct parser {
         else { self.unexpected(); }
     }
 
-    fn parse_foreign_item(+attrs: ~[attribute]) ->
-        @foreign_item {
-        self.parse_item_foreign_fn(attrs)
+    fn parse_foreign_item(+attrs: ~[attribute]) -> @foreign_item {
+        if self.is_keyword(~"const") {
+            self.parse_item_foreign_const(move attrs)
+        } else {
+            self.parse_item_foreign_fn(move attrs)
+        }
     }
 
     fn parse_foreign_mod_items(+first_item_attrs: ~[attribute]) ->

src/libsyntax/print/pprust.rs

@@ -421,6 +421,14 @@ fn print_foreign_item(s: ps, item: @ast::foreign_item) {
         word(s.s, ~";");
         end(s); // end the outer fn box
       }
+      ast::foreign_item_const(t) => {
+        head(s, ~"const");
+        print_ident(s, item.ident);
+        word_space(s, ~":");
+        print_type(s, t);
+        word(s.s, ~";");
+        end(s); // end the head-ibox
+      }
     }
 }
 

src/libsyntax/visit.rs

@@ -254,6 +254,9 @@ fn visit_foreign_item<E>(ni: @foreign_item, e: E, v: vt<E>) {
         v.visit_ty_params(tps, e, v);
         visit_fn_decl(fd, e, v);
       }
+      foreign_item_const(t) => {
+        v.visit_ty(t, e, v);
+      }
     }
 }
 

src/rustc/metadata/encoder.rs

@@ -803,6 +803,14 @@ fn encode_info_for_foreign_item(ecx: @encode_ctxt, ebml_w: ebml::writer,
         }
         encode_path(ecx, ebml_w, path, ast_map::path_name(nitem.ident));
       }
+      foreign_item_const(t) => {
+        encode_def_id(ebml_w, local_def(nitem.id));
+        encode_family(ebml_w, 'c');
+        encode_type(ecx, ebml_w, node_id_to_type(ecx.tcx, nitem.id));
+        encode_symbol(ecx, ebml_w, nitem.id);
+        encode_path(ecx, ebml_w, path, ast_map::path_name(nitem.ident));
+        ebml_w.end_tag();
+      }
     }
     ebml_w.end_tag();
 }

src/rustc/middle/lint.rs

@@ -420,6 +420,7 @@ fn check_item_ctypes(cx: ty::ctxt, it: @ast::item) {
               ast::foreign_item_fn(decl, _, tps) => {
                 check_foreign_fn(cx, it.id, decl);
               }
+              ast::foreign_item_const(*) => {}  // XXX: Not implemented.
             }
         }
       }

src/rustc/middle/resolve3.rs

@@ -25,23 +25,23 @@ import syntax::ast::{enum_variant_kind, expr, expr_again, expr_assign_op};
 import syntax::ast::{expr_binary, expr_break, expr_cast, expr_field, expr_fn};
 import syntax::ast::{expr_fn_block, expr_index, expr_loop};
 import syntax::ast::{expr_path, expr_struct, expr_unary, fn_decl};
-import syntax::ast::{foreign_item, foreign_item_fn, ge, gt, ident, trait_ref};
-import syntax::ast::{impure_fn, inherited, item, item_class, item_const};
-import syntax::ast::{item_enum, item_fn, item_mac, item_foreign_mod};
-import syntax::ast::{item_impl, item_mod, item_trait, item_ty, le, local};
-import syntax::ast::{local_crate, lt, method, mul, ne, neg, node_id, pat};
-import syntax::ast::{pat_enum, pat_ident, path, prim_ty, pat_box, pat_uniq};
+import syntax::ast::{foreign_item, foreign_item_const, foreign_item_fn, ge};
+import syntax::ast::{gt, ident, impure_fn, inherited, item, item_class};
+import syntax::ast::{item_const, item_enum, item_fn, item_foreign_mod};
+import syntax::ast::{item_impl, item_mac, item_mod, item_trait, item_ty, le};
+import syntax::ast::{local, local_crate, lt, method, mul, ne, neg, node_id};
+import syntax::ast::{pat, pat_enum, pat_ident, path, prim_ty, pat_box};
 import syntax::ast::{pat_lit, pat_range, pat_rec, pat_struct, pat_tup};
-import syntax::ast::{pat_wild, private, provided, public, required, rem};
-import syntax::ast::{self_ty_};
-import syntax::ast::{shl, stmt_decl, struct_field, struct_variant_kind};
-import syntax::ast::{sty_static, subtract, tuple_variant_kind, ty};
-import syntax::ast::{ty_bool, ty_char, ty_f, ty_f32, ty_f64, ty_float, ty_i};
-import syntax::ast::{ty_i16, ty_i32, ty_i64, ty_i8, ty_int, ty_param};
-import syntax::ast::{ty_path, ty_str, ty_u, ty_u16, ty_u32, ty_u64, ty_u8};
-import syntax::ast::{ty_uint, variant, view_item, view_item_export};
-import syntax::ast::{view_item_import, view_item_use, view_path_glob};
-import syntax::ast::{view_path_list, view_path_simple, visibility};
+import syntax::ast::{pat_uniq, pat_wild, private, provided, public, required};
+import syntax::ast::{rem, self_ty_, shl, stmt_decl, struct_field};
+import syntax::ast::{struct_variant_kind, sty_static, subtract, trait_ref};
+import syntax::ast::{tuple_variant_kind, ty, ty_bool, ty_char, ty_f, ty_f32};
+import syntax::ast::{ty_f64, ty_float, ty_i, ty_i16, ty_i32, ty_i64, ty_i8};
+import syntax::ast::{ty_int, ty_param, ty_path, ty_str, ty_u, ty_u16, ty_u32};
+import syntax::ast::{ty_u64, ty_u8, ty_uint, variant, view_item};
+import syntax::ast::{view_item_export, view_item_import, view_item_use};
+import syntax::ast::{view_path_glob, view_path_list, view_path_simple};
+import syntax::ast::{visibility};
 import syntax::ast_util::{def_id_of_def, dummy_sp, local_def, new_def_hash};
 import syntax::ast_util::{path_to_ident, walk_pat, trait_method_to_ty_method};
 import syntax::attr::{attr_metas, contains_name};
@@ -1213,26 +1213,27 @@ struct Resolver {
                                                 vt<ReducedGraphParent>) {
 
         let name = foreign_item.ident;
+        let (name_bindings, new_parent) =
+            self.add_child(name, parent, ~[ValueNS], foreign_item.span);
 
         match foreign_item.node {
             foreign_item_fn(fn_decl, purity, type_parameters) => {
-              let (name_bindings, new_parent) = self.add_child(name, parent,
-                                              ~[ValueNS], foreign_item.span);
-
                 let def = def_fn(local_def(foreign_item.id), purity);
                 (*name_bindings).define_value(Public, def, foreign_item.span);
 
                 do self.with_type_parameter_rib
-                        (HasTypeParameters(&type_parameters,
-                                           foreign_item.id,
-                                           0u,
-                                           NormalRibKind)) || {
-
+                        (HasTypeParameters(&type_parameters, foreign_item.id,
+                                           0u, NormalRibKind)) {
                     visit_foreign_item(foreign_item, new_parent, visitor);
                 }
             }
-        }
+            foreign_item_const(item_type) => {
+                let def = def_const(local_def(foreign_item.id));
+                (*name_bindings).define_value(Public, def, foreign_item.span);
 
+                visit_foreign_item(foreign_item, new_parent, visitor);
+            }
+        }
     }
 
     fn build_reduced_graph_for_block(block: blk,
@@ -2953,6 +2954,10 @@ struct Resolver {
                                                        visitor);
                                 }
                             }
+                            foreign_item_const(item_type) => {
+                                visit_foreign_item(foreign_item, (),
+                                                   visitor);
+                            }
                         }
                     }
                 }

src/rustc/middle/trans/base.rs

@@ -5414,9 +5414,22 @@ fn get_item_val(ccx: @crate_ctxt, id: ast::node_id) -> ValueRef {
           }
           ast_map::node_foreign_item(ni, _, pth) => {
             exprt = true;
-            register_fn(ccx, ni.span,
-                        vec::append(*pth, ~[path_name(ni.ident)]),
-                        ni.id)
+            match ni.node {
+                ast::foreign_item_fn(*) => {
+                    register_fn(ccx, ni.span,
+                                vec::append(*pth, ~[path_name(ni.ident)]),
+                                ni.id)
+                }
+                ast::foreign_item_const(*) => {
+                    let typ = ty::node_id_to_type(ccx.tcx, ni.id);
+                    let ident = ccx.sess.parse_sess.interner.get(ni.ident);
+                    let g = do str::as_c_str(*ident) |buf| {
+                        llvm::LLVMAddGlobal(ccx.llmod, type_of(ccx, typ), buf)
+                    };
+                    ccx.item_symbols.insert(ni.id, copy *ident);
+                    g
+                }
+            }
           }
           ast_map::node_ctor(nm, _, ctor, _, pt) => {
             let my_path = vec::append(*pt, ~[path_name(nm)]);

src/rustc/middle/trans/foreign.rs

@@ -789,6 +789,7 @@ fn trans_foreign_mod(ccx: @crate_ctxt,
               }
           }
         }
+        ast::foreign_item_const(*) => {}
       }
     }
 }

src/rustc/middle/typeck/collect.rs

@@ -537,12 +537,8 @@ fn convert_foreign(ccx: @crate_ctxt, i: @ast::foreign_item) {
     // type of the foreign item. We simply write it into the node type
     // table.
     let tpt = ty_of_foreign_item(ccx, i);
-    match i.node {
-      ast::foreign_item_fn(*) => {
-        write_ty_to_tcx(ccx.tcx, i.id, tpt.ty);
-        ccx.tcx.tcache.insert(local_def(i.id), tpt);
-      }
-    }
+    write_ty_to_tcx(ccx.tcx, i.id, tpt.ty);
+    ccx.tcx.tcache.insert(local_def(i.id), tpt);
 }
 
 fn ty_of_method(ccx: @crate_ctxt,
@@ -695,6 +691,14 @@ fn ty_of_foreign_item(ccx: @crate_ctxt, it: @ast::foreign_item)
         return ty_of_foreign_fn_decl(ccx, fn_decl, purity, params,
                                      local_def(it.id));
       }
+      ast::foreign_item_const(t) => {
+        let rb = in_binding_rscope(empty_rscope);
+        return {
+            bounds: @~[],
+            region_param: none,
+            ty: ast_ty_to_ty(ccx, rb, t)
+        };
+      }
     }
 }
 

src/rustdoc/extract.rs

@@ -130,16 +130,19 @@ fn nmoddoc_from_mod(
     itemdoc: doc::itemdoc,
     module_: ast::foreign_mod
 ) -> doc::nmoddoc {
+    let mut fns = ~[];
+    for module_.items.each |item| {
+        let itemdoc = mk_itemdoc(item.id, to_str(item.ident));
+        match item.node {
+          ast::foreign_item_fn(*) => {
+            vec::push(fns, fndoc_from_fn(itemdoc));
+          }
+          ast::foreign_item_const(*) => {} // XXX: Not implemented.
+        }
+    }
     {
         item: itemdoc,
-        fns: do vec::map(module_.items) |item| {
-            let itemdoc = mk_itemdoc(item.id, to_str(item.ident));
-            match item.node {
-              ast::foreign_item_fn(*) => {
-                fndoc_from_fn(itemdoc)
-              }
-            }
-        },
+        fns: fns,
         index: none
     }
 }