Stop tracking CodeMap offsets in the parse session. Big simplification

5 files changed, 48 insertions, 96 deletions

diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs
index 5e600b48965..91aef76061e 100644
--- a/src/libsyntax/codemap.rs
+++ b/src/libsyntax/codemap.rs
@@ -201,25 +201,6 @@ pub struct FileMap {
 }
 
 pub impl FileMap {
-    static fn new_w_substr(+filename: FileName, +substr: FileSubstr,
-                           src: @~str,
-                           +start_pos: BytePos)
-        -> FileMap {
-        return FileMap {
-            name: filename, substr: substr, src: src,
-            start_pos: start_pos,
-            mut lines: ~[],
-            multibyte_chars: DVec()
-        };
-    }
-
-    static fn new(+filename: FileName, src: @~str,
-                  +start_pos: BytePos)
-        -> FileMap {
-        return FileMap::new_w_substr(filename, FssNone, src,
-                                     start_pos);
-    }
-
     fn next_line(&self, +pos: BytePos) {
         self.lines.push(pos);
     }
@@ -262,20 +243,30 @@ pub impl CodeMap {
         }
     }
 
-    pub fn add_filemap(&self, filemap: @FileMap) {
-        let expected_byte_pos = if self.files.len() == 0 {
+    fn new_filemap_w_substr(+filename: FileName, +substr: FileSubstr,
+                            src: @~str) -> @FileMap {
+        let start_pos = if self.files.len() == 0 {
             0
         } else {
             let last_start = self.files.last().start_pos.to_uint();
             let last_len = self.files.last().src.len();
             last_start + last_len
         };
-        let actual_byte_pos = filemap.start_pos.to_uint();
-        debug!("codemap: adding filemap: %s", filemap.name);
-        debug!("codemap: expected offset: %u", expected_byte_pos);
-        debug!("codemap: actual offset: %u", actual_byte_pos);
-        assert expected_byte_pos == actual_byte_pos;
+
+        let filemap = @FileMap {
+            name: filename, substr: substr, src: src,
+            start_pos: BytePos(start_pos),
+            mut lines: ~[],
+            multibyte_chars: DVec()
+        };
+
         self.files.push(filemap);
+
+        return filemap;
+    }
+
+    fn new_filemap(+filename: FileName, src: @~str) -> @FileMap {
+        return self.new_filemap_w_substr(filename, FssNone, src);
     }
 
     pub fn mk_substr_filename(&self, sp: span) -> ~str {
diff --git a/src/libsyntax/ext/source_util.rs b/src/libsyntax/ext/source_util.rs
index 726dbbb56e2..93cfaadcbd3 100644
--- a/src/libsyntax/ext/source_util.rs
+++ b/src/libsyntax/ext/source_util.rs
@@ -58,12 +58,11 @@ fn expand_include(cx: ext_ctxt, sp: span, arg: ast::mac_arg,
                   _body: ast::mac_body) -> @ast::expr {
     let args = get_mac_args(cx, sp, arg, 1u, option::Some(1u), ~"include");
     let file = expr_to_str(cx, args[0], ~"#include_str requires a string");
-    let (p, rdr) = parse::new_parser_etc_from_file(
+    let p = parse::new_parser_from_file(
         cx.parse_sess(), cx.cfg(),
         &res_rel_file(cx, sp, &Path(file)),
         parse::parser::SOURCE_FILE);
     let e = p.parse_expr();
-    parse::update_parse_sess_position(&cx.parse_sess(), &rdr);
     return e;
 }
 
diff --git a/src/libsyntax/parse.rs b/src/libsyntax/parse.rs
index 9c8d28680ed..d824f9f8a03 100644
--- a/src/libsyntax/parse.rs
+++ b/src/libsyntax/parse.rs
@@ -11,7 +11,6 @@ export parse_crate_from_source_str;
 export parse_expr_from_source_str, parse_item_from_source_str;
 export parse_stmt_from_source_str;
 export parse_from_source_str;
-export update_parse_sess_position;
 
 use parser::Parser;
 use attr::parser_attr;
@@ -28,8 +27,6 @@ type parse_sess = @{
     mut next_id: node_id,
     span_diagnostic: span_handler,
     interner: @ident_interner,
-    // must be kept up to date
-    mut pos: BytePos
 };
 
 fn new_parse_sess(demitter: Option<emitter>) -> parse_sess {
@@ -38,7 +35,6 @@ fn new_parse_sess(demitter: Option<emitter>) -> parse_sess {
              mut next_id: 1,
              span_diagnostic: mk_span_handler(mk_handler(demitter), cm),
              interner: mk_ident_interner(),
-             mut pos: BytePos(0)
             };
 }
 
@@ -48,7 +44,6 @@ fn new_parse_sess_special_handler(sh: span_handler, cm: @codemap::CodeMap)
              mut next_id: 1,
              span_diagnostic: sh,
              interner: mk_ident_interner(),
-             mut pos: BytePos(0)
              };
 }
 
@@ -66,14 +61,13 @@ fn parse_crate_from_file(input: &Path, cfg: ast::crate_cfg,
 
 fn parse_crate_from_crate_file(input: &Path, cfg: ast::crate_cfg,
                                sess: parse_sess) -> @ast::crate {
-    let (p, rdr) = new_parser_etc_from_file(sess, cfg, input,
-                                            parser::CRATE_FILE);
+    let p = new_parser_from_file(sess, cfg, input,
+                                 parser::CRATE_FILE);
     let lo = p.span.lo;
     let prefix = input.dir_path();
     let leading_attrs = p.parse_inner_attrs_and_next();
     let { inner: crate_attrs, next: first_cdir_attr } = leading_attrs;
     let cdirs = p.parse_crate_directives(token::EOF, first_cdir_attr);
-    update_parse_sess_position(&sess, &rdr);
     let cx = @{sess: sess, cfg: /* FIXME (#2543) */ copy p.cfg};
     let companionmod = input.filestem().map(|s| Path(*s));
     let (m, attrs) = eval::eval_crate_directives_to_mod(
@@ -90,52 +84,47 @@ fn parse_crate_from_crate_file(input: &Path, cfg: ast::crate_cfg,
 
 fn parse_crate_from_source_file(input: &Path, cfg: ast::crate_cfg,
                                 sess: parse_sess) -> @ast::crate {
-    let (p, rdr) = new_parser_etc_from_file(sess, cfg, input,
-                                            parser::SOURCE_FILE);
+    let p = new_parser_from_file(sess, cfg, input,
+                                 parser::SOURCE_FILE);
     let r = p.parse_crate_mod(cfg);
-    update_parse_sess_position(&sess, &rdr);
     return r;
 }
 
 fn parse_crate_from_source_str(name: ~str, source: @~str, cfg: ast::crate_cfg,
                                sess: parse_sess) -> @ast::crate {
-    let (p, rdr) = new_parser_etc_from_source_str(sess, cfg, name,
-                                                  codemap::FssNone, source);
+    let p = new_parser_from_source_str(sess, cfg, name,
+                                       codemap::FssNone, source);
     let r = p.parse_crate_mod(cfg);
     p.abort_if_errors();
-    update_parse_sess_position(&sess, &rdr);
     return r;
 }
 
 fn parse_expr_from_source_str(name: ~str, source: @~str, cfg: ast::crate_cfg,
                               sess: parse_sess) -> @ast::expr {
-    let (p, rdr) = new_parser_etc_from_source_str(sess, cfg, name,
-                                                  codemap::FssNone, source);
+    let p = new_parser_from_source_str(sess, cfg, name,
+                                       codemap::FssNone, source);
     let r = p.parse_expr();
     p.abort_if_errors();
-    update_parse_sess_position(&sess, &rdr);
     return r;
 }
 
 fn parse_item_from_source_str(name: ~str, source: @~str, cfg: ast::crate_cfg,
                               +attrs: ~[ast::attribute],
                               sess: parse_sess) -> Option<@ast::item> {
-    let (p, rdr) = new_parser_etc_from_source_str(sess, cfg, name,
-                                                  codemap::FssNone, source);
+    let p = new_parser_from_source_str(sess, cfg, name,
+                                       codemap::FssNone, source);
     let r = p.parse_item(attrs);
     p.abort_if_errors();
-    update_parse_sess_position(&sess, &rdr);
     return r;
 }
 
 fn parse_stmt_from_source_str(name: ~str, source: @~str, cfg: ast::crate_cfg,
                               +attrs: ~[ast::attribute],
                               sess: parse_sess) -> @ast::stmt {
-    let (p, rdr) = new_parser_etc_from_source_str(sess, cfg, name,
-                                                  codemap::FssNone, source);
+    let p = new_parser_from_source_str(sess, cfg, name,
+                                       codemap::FssNone, source);
     let r = p.parse_stmt(attrs);
     p.abort_if_errors();
-    update_parse_sess_position(&sess, &rdr);
     return r;
 }
 
@@ -145,14 +134,13 @@ fn parse_from_source_str<T>(f: fn (p: Parser) -> T,
                             sess: parse_sess)
     -> T
 {
-    let (p, rdr) = new_parser_etc_from_source_str(sess, cfg, name, ss,
-                                                  source);
+    let p = new_parser_from_source_str(sess, cfg, name, ss,
+                                       source);
     let r = f(p);
     if !p.reader.is_eof() {
         p.reader.fatal(~"expected end-of-string");
     }
     p.abort_if_errors();
-    update_parse_sess_position(&sess, &rdr);
     move r
 }
 
@@ -164,47 +152,28 @@ fn next_node_id(sess: parse_sess) -> node_id {
     return rv;
 }
 
-fn new_parser_etc_from_source_str(sess: parse_sess, cfg: ast::crate_cfg,
-                                  +name: ~str, +ss: codemap::FileSubstr,
-                                  source: @~str) -> (Parser, string_reader) {
-    let ftype = parser::SOURCE_FILE;
-    let filemap = @FileMap::new_w_substr
-        (name, ss, source, sess.pos);
-    sess.cm.add_filemap(filemap);
-    let srdr = lexer::new_string_reader(sess.span_diagnostic, filemap,
-                                        sess.interner);
-    return (Parser(sess, cfg, srdr as reader, ftype), srdr);
-}
-
 fn new_parser_from_source_str(sess: parse_sess, cfg: ast::crate_cfg,
                               +name: ~str, +ss: codemap::FileSubstr,
                               source: @~str) -> Parser {
-    let (p, _) = new_parser_etc_from_source_str(sess, cfg, name, ss, source);
-    move p
+    let ftype = parser::SOURCE_FILE;
+    let filemap = sess.cm.new_filemap_w_substr(name, ss, source);
+    let srdr = lexer::new_string_reader(sess.span_diagnostic, filemap,
+                                        sess.interner);
+    return Parser(sess, cfg, srdr as reader, ftype);
 }
 
-
-fn new_parser_etc_from_file(sess: parse_sess, cfg: ast::crate_cfg,
-                            path: &Path, ftype: parser::file_type) ->
-   (Parser, string_reader) {
+fn new_parser_from_file(sess: parse_sess, cfg: ast::crate_cfg,
+                        path: &Path, ftype: parser::file_type) -> Parser {
     let res = io::read_whole_file_str(path);
     match res {
       result::Ok(_) => { /* Continue. */ }
       result::Err(e) => sess.span_diagnostic.handler().fatal(e)
     }
     let src = @result::unwrap(res);
-    let filemap = @FileMap::new(path.to_str(), src,
-                                sess.pos);
-    sess.cm.add_filemap(filemap);
+    let filemap = sess.cm.new_filemap(path.to_str(), src);
     let srdr = lexer::new_string_reader(sess.span_diagnostic, filemap,
                                         sess.interner);
-    return (Parser(sess, cfg, srdr as reader, ftype), srdr);
-}
-
-fn new_parser_from_file(sess: parse_sess, cfg: ast::crate_cfg, path: &Path,
-                        ftype: parser::file_type) -> Parser {
-    let (p, _) = new_parser_etc_from_file(sess, cfg, path, ftype);
-    move p
+    return Parser(sess, cfg, srdr as reader, ftype);
 }
 
 fn new_parser_from_tt(sess: parse_sess, cfg: ast::crate_cfg,
@@ -213,7 +182,3 @@ fn new_parser_from_tt(sess: parse_sess, cfg: ast::crate_cfg,
                                     None, tt);
     return Parser(sess, cfg, trdr as reader, parser::SOURCE_FILE)
 }
-
-fn update_parse_sess_position(sess: &parse_sess, r: &lexer::string_reader) {
-    sess.pos = r.last_pos
-}
diff --git a/src/libsyntax/parse/comments.rs b/src/libsyntax/parse/comments.rs
index e3ac3e7dcbb..2a8bbe3b6d8 100644
--- a/src/libsyntax/parse/comments.rs
+++ b/src/libsyntax/parse/comments.rs
@@ -292,7 +292,8 @@ fn gather_comments_and_literals(span_diagnostic: diagnostic::span_handler,
    {cmnts: ~[cmnt], lits: ~[lit]} {
     let src = @str::from_bytes(srdr.read_whole_stream());
     let itr = parse::token::mk_fake_ident_interner();
-    let filemap = @FileMap::new(path, src, BytePos(0));
+    let cm = CodeMap::new();
+    let filemap = cm.new_filemap(path, src);
     let rdr = lexer::new_low_level_string_reader(
         span_diagnostic, filemap, itr);
 
diff --git a/src/libsyntax/parse/eval.rs b/src/libsyntax/parse/eval.rs
index 47dbc0cd6ee..f08f1954464 100644
--- a/src/libsyntax/parse/eval.rs
+++ b/src/libsyntax/parse/eval.rs
@@ -1,4 +1,3 @@
-use parse::update_parse_sess_position;
 use parser::{Parser, SOURCE_FILE};
 use attr::parser_attr;
 
@@ -63,11 +62,10 @@ fn parse_companion_mod(cx: ctx, prefix: &Path, suffix: &Option<Path>)
     let modpath = &companion_file(prefix, suffix);
     if file_exists(modpath) {
         debug!("found companion mod");
-        let (p0, r0) = new_parser_etc_from_file(cx.sess, cx.cfg,
-                                                modpath, SOURCE_FILE);
+        let p0 = new_parser_from_file(cx.sess, cx.cfg,
+                                      modpath, SOURCE_FILE);
         let inner_attrs = p0.parse_inner_attrs_and_next();
         let m0 = p0.parse_mod_items(token::EOF, inner_attrs.next);
-        update_parse_sess_position(&cx.sess, &r0);
         return (m0.view_items, m0.items, inner_attrs.inner);
     } else {
         return (~[], ~[], ~[]);
@@ -93,9 +91,9 @@ fn eval_crate_directive(cx: ctx, cdir: @ast::crate_directive, prefix: &Path,
         } else {
             prefix.push_many(file_path.components)
         };
-        let (p0, r0) =
-            new_parser_etc_from_file(cx.sess, cx.cfg,
-                                     &full_path, SOURCE_FILE);
+        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 = vec::append(attrs, inner_attrs.inner);
         let first_item_outer_attrs = inner_attrs.next;
@@ -104,8 +102,6 @@ fn eval_crate_directive(cx: ctx, cdir: @ast::crate_directive, prefix: &Path,
         let i = p0.mk_item(cdir.span.lo, cdir.span.hi,
                            /* FIXME (#2543) */ copy id,
                            ast::item_mod(m0), vis, mod_attrs);
-        // Thread defids, chpos and byte_pos through the parsers
-        update_parse_sess_position(&cx.sess, &r0);
         items.push(i);
       }
       ast::cdir_dir_mod(vis, id, cdirs, attrs) => {