Eliminate a copy in syntax::parse::new_parser_from_file

Fixing a FIXME turned out to be pretty involved. I added an io function
that returns a unique boxed string (for the contents of a file) rather than
a string, and went from there. Also made the src field of codemap a unique
boxed string. This doesn't seem to make that much difference in amount of
allocation according to valgrind (disappointingly), but I also had to introduce
a copy somewhere else pending a new snapshot, so maybe that's it.

6 files changed, 23 insertions, 20 deletions

diff --git a/src/librustsyntax/codemap.rs b/src/librustsyntax/codemap.rs
index b8579f6733d..2340bb5ab1d 100644
--- a/src/librustsyntax/codemap.rs
+++ b/src/librustsyntax/codemap.rs
@@ -38,7 +38,7 @@ enum file_substr {
 }
 
 type filemap =
-    @{name: filename, substr: file_substr, src: @str,
+    @{name: filename, substr: file_substr, src: ~str,
       start_pos: file_pos, mut lines: [file_pos]};
 
 type codemap = @{mut files: [filemap]};
@@ -48,7 +48,7 @@ type loc = {file: filemap, line: uint, col: uint};
 fn new_codemap() -> codemap { @{mut files: [] } }
 
 fn new_filemap_w_substr(filename: filename, substr: file_substr,
-                        src: @str,
+                        -src: ~str,
                         start_pos_ch: uint, start_pos_byte: uint)
    -> filemap {
     ret @{name: filename, substr: substr, src: src,
@@ -56,7 +56,7 @@ fn new_filemap_w_substr(filename: filename, substr: file_substr,
           mut lines: [{ch: start_pos_ch, byte: start_pos_byte}]};
 }
 
-fn new_filemap(filename: filename, src: @str,
+fn new_filemap(filename: filename, -src: ~str,
                start_pos_ch: uint, start_pos_byte: uint)
     -> filemap {
     ret new_filemap_w_substr(filename, fss_none, src,
diff --git a/src/librustsyntax/ext/expand.rs b/src/librustsyntax/ext/expand.rs
index f70a75bd96a..ae4fc082141 100644
--- a/src/librustsyntax/ext/expand.rs
+++ b/src/librustsyntax/ext/expand.rs
@@ -121,7 +121,7 @@ fn expand_crate(parse_sess: parse::parse_sess,
             with *afp};
     let f = make_fold(f_pre);
     let cm = parse_expr_from_source_str("<core-macros>",
-                                        @core_macros(),
+                                        ~core_macros(),
                                         cfg,
                                         parse_sess);
 
diff --git a/src/librustsyntax/parse.rs b/src/librustsyntax/parse.rs
index d1a997187da..d735af6d117 100644
--- a/src/librustsyntax/parse.rs
+++ b/src/librustsyntax/parse.rs
@@ -73,20 +73,22 @@ fn parse_crate_from_source_file(input: str, cfg: ast::crate_cfg,
     ret r;
 }
 
-fn parse_crate_from_source_str(name: str, source: @str, cfg: ast::crate_cfg,
-                               sess: parse_sess) -> @ast::crate {
+fn parse_crate_from_source_str(name: str, source: ~str,
+               cfg: ast::crate_cfg, sess: parse_sess) -> @ast::crate {
+  // FIXME: Get rid of copy once there's a snapshot
     let p = new_parser_from_source_str(
-        sess, cfg, name, codemap::fss_none, source);
+           sess, cfg, name, codemap::fss_none, @(*source));
     let r = parser::parse_crate_mod(p, cfg);
     sess.chpos = p.reader.chpos;
     sess.byte_pos = sess.byte_pos + p.reader.pos;
     ret r;
 }
 
-fn parse_expr_from_source_str(name: str, source: @str, cfg: ast::crate_cfg,
-                              sess: parse_sess) -> @ast::expr {
+fn parse_expr_from_source_str(name: str, source: ~str,
+               cfg: ast::crate_cfg, sess: parse_sess) -> @ast::expr {
+  // FIXME: Get rid of copy once there's a snapshot
     let p = new_parser_from_source_str(
-        sess, cfg, name, codemap::fss_none, source);
+        sess, cfg, name, codemap::fss_none, @(*source));
     let r = parser::parse_expr(p);
     sess.chpos = p.reader.chpos;
     sess.byte_pos = sess.byte_pos + p.reader.pos;
@@ -134,12 +136,15 @@ fn new_parser(sess: parse_sess, cfg: ast::crate_cfg, rdr: lexer::reader,
       restricted_keywords: token::restricted_keyword_table()}
 }
 
+/* FIXME: still taking an @ b/c #ast using this.
+ Fix when there's a snapshot */
 fn new_parser_from_source_str(sess: parse_sess, cfg: ast::crate_cfg,
                               name: str, ss: codemap::file_substr,
                               source: @str) -> parser {
     let ftype = parser::SOURCE_FILE;
     let filemap = codemap::new_filemap_w_substr
-        (name, ss, source, sess.chpos, sess.byte_pos);
+      // FIXME: remove copy once there's a new snap
+      (name, ss, ~(*source), sess.chpos, sess.byte_pos);
     sess.cm.files += [filemap];
     let itr = @interner::mk(str::hash, str::eq);
     let rdr = lexer::new_reader(sess.span_diagnostic,
@@ -148,12 +153,10 @@ fn new_parser_from_source_str(sess: parse_sess, cfg: ast::crate_cfg,
 }
 
 fn new_parser_from_file(sess: parse_sess, cfg: ast::crate_cfg, path: str,
-                        ftype: parser::file_type) ->
-   parser {
-    let src = alt io::read_whole_file_str(path) {
+                        ftype: parser::file_type) -> parser {
+    let src = alt io::read_whole_file_ref(path) {
       result::ok(src) {
-        // FIXME: This copy is unfortunate
-        @src
+        src
       }
       result::err(e) {
         sess.span_diagnostic.handler().fatal(e)
diff --git a/src/librustsyntax/parse/comments.rs b/src/librustsyntax/parse/comments.rs
index 493ed7b369b..15319e21f40 100644
--- a/src/librustsyntax/parse/comments.rs
+++ b/src/librustsyntax/parse/comments.rs
@@ -154,7 +154,7 @@ fn gather_comments_and_literals(span_diagnostic: diagnostic::span_handler,
                                 path: str,
                                 srdr: io::reader) ->
    {cmnts: [cmnt], lits: [lit]} {
-    let src = @str::from_bytes(srdr.read_whole_stream());
+    let src = ~str::from_bytes(srdr.read_whole_stream());
     let itr = @interner::mk::<str>(str::hash, str::eq);
     let rdr = new_reader(span_diagnostic,
                          codemap::new_filemap(path, src, 0u, 0u), itr);
diff --git a/src/librustsyntax/parse/lexer.rs b/src/librustsyntax/parse/lexer.rs
index ec9f785db2f..321bf076a1e 100644
--- a/src/librustsyntax/parse/lexer.rs
+++ b/src/librustsyntax/parse/lexer.rs
@@ -6,7 +6,7 @@ export reader, new_reader, next_token, is_whitespace;
 
 type reader = @{
     span_diagnostic: diagnostic::span_handler,
-    src: @str,
+    src: ~str,
     mut col: uint,
     mut pos: uint,
     mut curr: char,
diff --git a/src/librustsyntax/parse/token.rs b/src/librustsyntax/parse/token.rs
index 3f9ce9d91b6..c962d4ec16c 100644
--- a/src/librustsyntax/parse/token.rs
+++ b/src/librustsyntax/parse/token.rs
@@ -124,7 +124,7 @@ fn to_str(in: interner<str>, t: token) -> str {
 
       /* Literals */
       LIT_INT(c, ast::ty_char) {
-        // FIXME: escape.
+        // FIXME: escape. (#2306)
         let mut tmp = "'";
         str::push_char(tmp, c as char);
         str::push_char(tmp, '\'');
@@ -140,7 +140,7 @@ fn to_str(in: interner<str>, t: token) -> str {
         ret interner::get::<str>(in, s) +
             ast_util::float_ty_to_str(t);
       }
-      LIT_STR(s) { // FIXME: escape.
+      LIT_STR(s) { // FIXME: escape. (#2306)
         ret "\"" + interner::get::<str>(in, s) + "\"";
       }