1 files changed, 107 insertions, 0 deletions
diff --git a/src/librustc/front/std_inject.rs b/src/librustc/front/std_inject.rs
new file mode 100644
index 00000000000..e84f552fd1c
--- /dev/null
+++ b/src/librustc/front/std_inject.rs
@@ -0,0 +1,107 @@
+// Copyright 2012 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.
+
+use driver::session::Session;
+
+use syntax::ast;
+use syntax::attr;
+use syntax::codemap;
+use syntax::codemap::dummy_sp;
+use syntax::fold;
+
+static STD_VERSION: &'static str = "0.7-pre";
+
+pub fn maybe_inject_libstd_ref(sess: Session, crate: @ast::crate)
+                               -> @ast::crate {
+    if use_std(crate) {
+        inject_libstd_ref(sess, crate)
+    } else {
+        crate
+    }
+}
+
+fn use_std(crate: @ast::crate) -> bool {
+    !attr::attrs_contains_name(crate.node.attrs, "no_std")
+}
+
+fn inject_libstd_ref(sess: Session, crate: @ast::crate) -> @ast::crate {
+    fn spanned<T:Copy>(x: T) -> codemap::spanned<T> {
+        codemap::spanned { node: x, span: dummy_sp() }
+    }
+
+    let precursor = @fold::AstFoldFns {
+        fold_crate: |crate, span, fld| {
+            let n1 = sess.next_node_id();
+            let vi1 = @ast::view_item {
+                node: ast::view_item_extern_mod(
+                        sess.ident_of("core"), ~[], n1),
+                attrs: ~[
+                    spanned(ast::attribute_ {
+                        style: ast::attr_inner,
+                        value: @spanned(ast::meta_name_value(
+                            @~"vers",
+                            spanned(ast::lit_str(@STD_VERSION.to_str()))
+                        )),
+                        is_sugared_doc: false
+                    })
+                ],
+                vis: ast::private,
+                span: dummy_sp()
+            };
+
+            let vis = vec::append(~[vi1], crate.module.view_items);
+            let mut new_module = ast::_mod {
+                view_items: vis,
+                ../*bad*/copy crate.module
+            };
+            new_module = fld.fold_mod(&new_module);
+
+            // FIXME #2543: Bad copy.
+            let new_crate = ast::crate_ {
+                module: new_module,
+                ..copy *crate
+            };
+            (new_crate, span)
+        },
+        fold_mod: |module, fld| {
+            let n2 = sess.next_node_id();
+
+            let prelude_path = @ast::Path {
+                span: dummy_sp(),
+                global: false,
+                idents: ~[
+                    sess.ident_of("core"),
+                    sess.ident_of("prelude")
+                ],
+                rp: None,
+                types: ~[]
+            };
+
+            let vp = @spanned(ast::view_path_glob(prelude_path, n2));
+            let vi2 = @ast::view_item { node: ast::view_item_use(~[vp]),
+                                        attrs: ~[],
+                                        vis: ast::private,
+                                        span: dummy_sp() };
+
+            let vis = vec::append(~[vi2], module.view_items);
+
+            // FIXME #2543: Bad copy.
+            let new_module = ast::_mod {
+                view_items: vis,
+                ..copy *module
+            };
+            fold::noop_fold_mod(&new_module, fld)
+        },
+        ..*fold::default_ast_fold()
+    };
+
+    let fold = fold::make_fold(precursor);
+    @fold.fold_crate(crate)
+}