1 files changed, 142 insertions, 0 deletions
diff --git a/src/libsyntax/parse/eval.rs b/src/libsyntax/parse/eval.rs
new file mode 100644
index 00000000000..98d75499878
--- /dev/null
+++ b/src/libsyntax/parse/eval.rs
@@ -0,0 +1,142 @@
+import parser::{parser, SOURCE_FILE};
+import attr::parser_attr;
+
+export eval_crate_directives_to_mod;
+
+type ctx =
+    @{sess: parse::parse_sess,
+      cfg: ast::crate_cfg};
+
+fn eval_crate_directives(cx: ctx, cdirs: [@ast::crate_directive], prefix: str,
+                         &view_items: [@ast::view_item],
+                         &items: [@ast::item]) {
+    for cdirs.each {|sub_cdir|
+        eval_crate_directive(cx, sub_cdir, prefix, view_items, items);
+    }
+}
+
+fn eval_crate_directives_to_mod(cx: ctx, cdirs: [@ast::crate_directive],
+                                prefix: str, suffix: option<str>)
+    -> (ast::_mod, [ast::attribute]) {
+    #debug("eval crate prefix: %s", prefix);
+    #debug("eval crate suffix: %s",
+           option::get_default(suffix, "none"));
+    let (cview_items, citems, cattrs)
+        = parse_companion_mod(cx, prefix, suffix);
+    let mut view_items: [@ast::view_item] = [];
+    let mut items: [@ast::item] = [];
+    eval_crate_directives(cx, cdirs, prefix, view_items, items);
+    ret ({view_items: view_items + cview_items,
+          items: items + citems},
+         cattrs);
+}
+
+/*
+The 'companion mod'. So .rc crates and directory mod crate directives define
+modules but not a .rs file to fill those mods with stuff. The companion mod is
+a convention for location a .rs file to go with them.  For .rc files the
+companion mod is a .rs file with the same name; for directory mods the
+companion mod is a .rs file with the same name as the directory.
+
+We build the path to the companion mod by combining the prefix and the
+optional suffix then adding the .rs extension.
+*/
+fn parse_companion_mod(cx: ctx, prefix: str, suffix: option<str>)
+    -> ([@ast::view_item], [@ast::item], [ast::attribute]) {
+
+    fn companion_file(prefix: str, suffix: option<str>) -> str {
+        ret alt suffix {
+          option::some(s) { path::connect(prefix, s) }
+          option::none { prefix }
+        } + ".rs";
+    }
+
+    fn file_exists(path: str) -> bool {
+        // Crude, but there's no lib function for this and I'm not
+        // up to writing it just now
+        alt io::file_reader(path) {
+          result::ok(_) { true }
+          result::err(_) { false }
+        }
+    }
+
+    let modpath = companion_file(prefix, suffix);
+    #debug("looking for companion mod %s", modpath);
+    if file_exists(modpath) {
+        #debug("found companion mod");
+        let p0 = new_parser_from_file(cx.sess, cx.cfg, modpath, SOURCE_FILE);
+        let inner_attrs = p0.parse_inner_attrs_and_next();
+        let first_item_outer_attrs = inner_attrs.next;
+        let m0 = p0.parse_mod_items(token::EOF, first_item_outer_attrs);
+        cx.sess.chpos = p0.reader.chpos;
+        cx.sess.byte_pos = cx.sess.byte_pos + p0.reader.pos;
+        ret (m0.view_items, m0.items, inner_attrs.inner);
+    } else {
+        ret ([], [], []);
+    }
+}
+
+fn cdir_path_opt(id: str, attrs: [ast::attribute]) -> str {
+    alt ::attr::first_attr_value_str_by_name(attrs, "path") {
+      some(d) {
+        ret d;
+      }
+      none { ret id; }
+    }
+}
+
+fn eval_crate_directive(cx: ctx, cdir: @ast::crate_directive, prefix: str,
+                        &view_items: [@ast::view_item],
+                        &items: [@ast::item]) {
+    alt cdir.node {
+      ast::cdir_src_mod(id, attrs) {
+        let file_path = cdir_path_opt(id + ".rs", attrs);
+        let full_path =
+            if path::path_is_absolute(file_path) {
+                file_path
+            } else { prefix + path::path_sep() + file_path };
+        let p0 =
+            new_parser_from_file(cx.sess, cx.cfg, full_path, SOURCE_FILE);
+        let inner_attrs = p0.parse_inner_attrs_and_next();
+        let mod_attrs = attrs + inner_attrs.inner;
+        let first_item_outer_attrs = inner_attrs.next;
+        let m0 = p0.parse_mod_items(token::EOF, first_item_outer_attrs);
+
+        let i = p0.mk_item(cdir.span.lo, cdir.span.hi, id,
+                           ast::item_mod(m0), ast::public, mod_attrs);
+        // Thread defids, chpos and byte_pos through the parsers
+        cx.sess.chpos = p0.reader.chpos;
+        cx.sess.byte_pos = cx.sess.byte_pos + p0.reader.pos;
+        items += [i];
+      }
+      ast::cdir_dir_mod(id, cdirs, attrs) {
+        let path = cdir_path_opt(id, attrs);
+        let full_path =
+            if path::path_is_absolute(path) {
+                path
+            } else { prefix + path::path_sep() + path };
+        let (m0, a0) = eval_crate_directives_to_mod(
+            cx, cdirs, full_path, none);
+        let i =
+            @{ident: id,
+              attrs: attrs + a0,
+              id: cx.sess.next_id,
+              node: ast::item_mod(m0),
+              vis: ast::public,
+              span: cdir.span};
+        cx.sess.next_id += 1;
+        items += [i];
+      }
+      ast::cdir_view_item(vi) { view_items += [vi]; }
+      ast::cdir_syntax(pth) { }
+    }
+}
+//
+// Local Variables:
+// mode: rust
+// fill-column: 78;
+// indent-tabs-mode: nil
+// c-basic-offset: 4
+// buffer-file-coding-system: utf-8-unix
+// End:
+//