auto merge of #8185 : alexcrichton/rust/issue-8179, r=pcwalton

* All globals marked as `pub` won't have the `internal` linkage type set
* All global references across crates are forced to use the address of the
  global in the other crate via an external reference.

r? @graydon

Closes #8179 

4 files changed, 58 insertions, 17 deletions

diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index b683014cccf..caf54c73f3b 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -2458,7 +2458,7 @@ pub fn get_item_val(ccx: @mut CrateContext, id: ast::NodeId) -> ValueRef {
                             // LLVM type is not fully determined by the Rust type.
                             let v = consts::const_expr(ccx, expr);
                             ccx.const_values.insert(id, v);
-                            exprt = m == ast::m_mutbl;
+                            exprt = (m == ast::m_mutbl || i.vis == ast::public);
 
                             unsafe {
                                 let llty = llvm::LLVMTypeOf(v);
diff --git a/src/librustc/middle/trans/expr.rs b/src/librustc/middle/trans/expr.rs
index 5ad18b63c76..c5b3d328f30 100644
--- a/src/librustc/middle/trans/expr.rs
+++ b/src/librustc/middle/trans/expr.rs
@@ -115,7 +115,7 @@ return type, such as `while` loops or assignments (`a = b`).
 
 
 use back::abi;
-use lib::llvm::{ValueRef, llvm};
+use lib::llvm::{ValueRef, llvm, SetLinkage, ExternalLinkage};
 use lib;
 use metadata::csearch;
 use middle::trans::_match;
@@ -132,7 +132,6 @@ use middle::trans::consts;
 use middle::trans::controlflow;
 use middle::trans::datum::*;
 use middle::trans::debuginfo;
-use middle::trans::inline;
 use middle::trans::machine;
 use middle::trans::meth;
 use middle::trans::tvec;
@@ -148,7 +147,6 @@ use middle::trans::machine::llsize_of;
 
 use middle::trans::type_::Type;
 
-use std::cast::transmute;
 use std::hashmap::HashMap;
 use std::vec;
 use syntax::print::pprust::{expr_to_str};
@@ -936,20 +934,10 @@ fn trans_lvalue_unadjusted(bcx: @mut Block, expr: @ast::expr) -> DatumBlock {
         //! Translates a reference to a path.
 
         let _icx = push_ctxt("trans_def_lvalue");
-        let ccx = bcx.ccx();
         match def {
             ast::def_static(did, _) => {
                 let const_ty = expr_ty(bcx, ref_expr);
 
-                fn get_did(ccx: @mut CrateContext, did: ast::def_id)
-                    -> ast::def_id {
-                    if did.crate != ast::LOCAL_CRATE {
-                        inline::maybe_instantiate_inline(ccx, did)
-                    } else {
-                        did
-                    }
-                }
-
                 fn get_val(bcx: @mut Block, did: ast::def_id, const_ty: ty::t)
                            -> ValueRef {
                     // For external constants, we don't inline.
@@ -976,8 +964,12 @@ fn trans_lvalue_unadjusted(bcx: @mut Block, expr: @ast::expr) -> DatumBlock {
                             let symbol = csearch::get_symbol(
                                 bcx.ccx().sess.cstore,
                                 did);
-                            let llval = llvm::LLVMAddGlobal( bcx.ccx().llmod, llty.to_ref(),
-                                transmute::<&u8,*i8>(&symbol[0]));
+                            let llval = do symbol.as_c_str |buf| {
+                                llvm::LLVMAddGlobal(bcx.ccx().llmod,
+                                                    llty.to_ref(),
+                                                    buf)
+                            };
+                            SetLinkage(llval, ExternalLinkage);
                             let extern_const_values = &mut bcx.ccx().extern_const_values;
                             extern_const_values.insert(did, llval);
                             llval
@@ -985,7 +977,6 @@ fn trans_lvalue_unadjusted(bcx: @mut Block, expr: @ast::expr) -> DatumBlock {
                     }
                 }
 
-                let did = get_did(ccx, did);
                 let val = get_val(bcx, did, const_ty);
                 DatumBlock {
                     bcx: bcx,
diff --git a/src/test/auxiliary/xcrate_static_addresses.rs b/src/test/auxiliary/xcrate_static_addresses.rs
new file mode 100644
index 00000000000..3a05462d856
--- /dev/null
+++ b/src/test/auxiliary/xcrate_static_addresses.rs
@@ -0,0 +1,23 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+pub static global: int = 3;
+
+pub fn verify_same(a: &'static int) {
+    let a = a as *int as uint;
+    let b = &global as *int as uint;
+    assert_eq!(a, b);
+}
+
+condition!{ pub test: int -> (); }
+
+pub fn raise() {
+    test::cond.raise(3);
+}
diff --git a/src/test/run-pass/xcrate-static-addresses.rs b/src/test/run-pass/xcrate-static-addresses.rs
new file mode 100644
index 00000000000..059a6f75ac8
--- /dev/null
+++ b/src/test/run-pass/xcrate-static-addresses.rs
@@ -0,0 +1,27 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// xfail-fast
+// aux-build:xcrate_static_addresses.rs
+
+extern mod xcrate_static_addresses;
+
+use other = xcrate_static_addresses;
+
+pub fn main() {
+    other::verify_same(&other::global);
+
+    // Previously this fail'd because there were two addresses that were being
+    // used when declaring constants.
+    do other::test::cond.trap(|_| {
+    }).inside {
+        other::raise();
+    }
+}