Fix inner statics having the same symbol name

Before, the path name for all items defined in methods of traits and impls never
took into account the name of the method. This meant that if you had two statics
of the same name in two different methods the statics would end up having the
same symbol named (even after mangling) because the path components leading to
the symbol were exactly the same (just __extensions__ and the static name).

It turns out that if you add the symbol "A" twice to LLVM, it automatically
makes the second one "A1" instead of "A". What this meant is that in local crate
compilations we never found this bug. Even across crates, this was never a
problem. The problem arises when you have generic methods that don't get
generated at compile-time of a library. If the statics were re-added to LLVM by
a client crate of a library in a different order, you would reference different
constants (the integer suffixes wouldn't be guaranteed to be the same).

This fixes the problem by adding the method name to symbol path when building
the ast_map. In doing so, two symbols in two different methods are disambiguated
against.

Author: alexcrichton

src/libsyntax/ast_map.rs

@@ -153,7 +153,15 @@ impl Ctx {
         for a in decl.inputs.iter() {
             self.map.insert(a.id, node_arg);
         }
+        match *fk {
+            visit::fk_method(name, _, _) => { self.path.push(path_name(name)) }
+            _ => {}
+        }
         visit::walk_fn(self, fk, decl, body, sp, id, ());
+        match *fk {
+            visit::fk_method(*) => { self.path.pop(); }
+            _ => {}
+        }
     }
 
     fn map_stmt(&mut self, stmt: @stmt) {

src/test/auxiliary/inner_static.rs

@@ -0,0 +1,28 @@
+// 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 struct A<T>;
+
+impl<T> A<T> {
+    pub fn foo(&self) -> int {
+        static a: int = 5;
+        return a
+    }
+
+    pub fn bar(&self) -> int {
+        static a: int = 3;
+        return a;
+    }
+}
+
+pub fn foo() -> int {
+    let a = A::<()>;
+    return a.foo() + a.bar();
+}

src/test/run-pass/inner-static.rs

@@ -0,0 +1,19 @@
+// 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.
+
+// aux-build:inner_static.rs
+// xfail-fast
+
+extern mod inner_static;
+
+pub fn main() {
+    let a = inner_static::A::<()>;
+    assert_eq!(a.bar(), 3);
+}