auto merge of #9936 : madjar/rust/master, r=alexcrichton

This should close #9468.

I removed the test stating that nested comments should not be implemented.

I had a little chicken-and-egg problem because a comment of the std contains "/*", and adding support for nested comment creates a backward incompatibility in that case, so I had to use a dirty hack to get stage1 and stage2 to compile. This part should be revert when this commit lands in a snapshot.

This is my first non-typo contribution, so I'm open to any comment.

Author: bors

src/libextra/glob.rs

@@ -39,32 +39,32 @@ pub struct GlobIterator {
     priv todo: ~[(Path,uint)]
 }
 
-/**
- * Return an iterator that produces all the Paths that match the given pattern,
- * which may be absolute or relative to the current working directory.
- *
- * This method uses the default match options and is equivalent to calling
- * `glob_with(pattern, MatchOptions::new())`. Use `glob_with` directly if you
- * want to use non-default match options.
- *
- * # Example
- *
- * Consider a directory `/media/pictures` containing only the files `kittens.jpg`,
- * `puppies.jpg` and `hamsters.gif`:
- *
- * ```rust
- * for path in glob("/media/pictures/*.jpg") {
- *     println(path.to_str());
- * }
- * ```
- *
- * The above code will print:
- *
- * ```
- * /media/pictures/kittens.jpg
- * /media/pictures/puppies.jpg
- * ```
- */
+///
+/// Return an iterator that produces all the Paths that match the given pattern,
+/// which may be absolute or relative to the current working directory.
+///
+/// is method uses the default match options and is equivalent to calling
+/// `glob_with(pattern, MatchOptions::new())`. Use `glob_with` directly if you
+/// want to use non-default match options.
+///
+/// # Example
+///
+/// Consider a directory `/media/pictures` containing only the files `kittens.jpg`,
+/// `puppies.jpg` and `hamsters.gif`:
+///
+/// ```rust
+/// for path in glob("/media/pictures/*.jpg") {
+///     println(path.to_str());
+/// }
+/// ```
+///
+/// The above code will print:
+///
+/// ```
+/// /media/pictures/kittens.jpg
+/// /media/pictures/puppies.jpg
+/// ```
+///
 pub fn glob(pattern: &str) -> GlobIterator {
     glob_with(pattern, MatchOptions::new())
 }

src/libstd/os.rs

@@ -546,12 +546,6 @@ pub fn self_exe_path() -> Option<Path> {
     load_self().and_then(|path| Path::new_opt(path).map(|mut p| { p.pop(); p }))
 }
 
-
-/**
- * Returns the path to the user's home directory, if known.
-}
-
-
 /**
  * Returns the path to the user's home directory, if known.
  *

src/libsyntax/parse/lexer.rs

@@ -373,49 +373,49 @@ pub fn is_block_non_doc_comment(s: &str) -> bool {
 fn consume_block_comment(rdr: @mut StringReader)
                       -> Option<TokenAndSpan> {
     // block comments starting with "/**" or "/*!" are doc-comments
-    let res = if rdr.curr == '*' || rdr.curr == '!' {
-        let start_bpos = rdr.pos - BytePos(3u);
-        while !(rdr.curr == '*' && nextch(rdr) == '/') && !is_eof(rdr) {
-            bump(rdr);
-        }
+    let is_doc_comment = rdr.curr == '*' || rdr.curr == '!';
+    let start_bpos = rdr.pos - BytePos(if is_doc_comment {3u} else {2u});
+
+    let mut level: int = 1;
+    while level > 0 {
         if is_eof(rdr) {
-            fatal_span(rdr, start_bpos, rdr.last_pos,
-                       ~"unterminated block doc-comment");
-        } else {
+            let msg = if is_doc_comment {
+                ~"unterminated block doc-comment"
+            } else {
+                ~"unterminated block comment"
+            };
+            fatal_span(rdr, start_bpos, rdr.last_pos, msg);
+        } else if rdr.curr == '/' && nextch(rdr) == '*' {
+            level += 1;
             bump(rdr);
             bump(rdr);
-            do with_str_from(rdr, start_bpos) |string| {
-                // but comments with only "*"s between two "/"s are not
-                if !is_block_non_doc_comment(string) {
-                    Some(TokenAndSpan{
-                         tok: token::DOC_COMMENT(str_to_ident(string)),
-                         sp: codemap::mk_sp(start_bpos, rdr.pos)
-                         })
-                } else {
-                    None
-                }
-            }
+        } else if rdr.curr == '*' && nextch(rdr) == '/' {
+            level -= 1;
+            bump(rdr);
+            bump(rdr);
+        } else {
+            bump(rdr);
         }
-    } else {
-        let start_bpos = rdr.last_pos - BytePos(2u);
-        loop {
-            if is_eof(rdr) {
-                fatal_span(rdr, start_bpos, rdr.last_pos,
-                           ~"unterminated block comment");
-            }
-            if rdr.curr == '*' && nextch(rdr) == '/' {
-                bump(rdr);
-                bump(rdr);
-                break;
+    }
+
+    let res = if is_doc_comment {
+        do with_str_from(rdr, start_bpos) |string| {
+            // but comments with only "*"s between two "/"s are not
+            if !is_block_non_doc_comment(string) {
+                Some(TokenAndSpan{
+                        tok: token::DOC_COMMENT(str_to_ident(string)),
+                        sp: codemap::mk_sp(start_bpos, rdr.pos)
+                    })
             } else {
-                bump(rdr);
+                None
             }
         }
+    } else {
         None
     };
-    // restart whitespace munch.
 
-   if res.is_some() { res } else { consume_whitespace_and_comments(rdr) }
+    // restart whitespace munch.
+    if res.is_some() { res } else { consume_whitespace_and_comments(rdr) }
 }
 
 fn scan_exponent(rdr: @mut StringReader, start_bpos: BytePos) -> Option<~str> {
@@ -1056,4 +1056,12 @@ mod test {
         assert!(!is_line_non_doc_comment("/// blah"));
         assert!(is_line_non_doc_comment("////"));
     }
+
+    #[test] fn nested_block_comments() {
+        let env = setup(@"/* /* */ */'a'");
+        let TokenAndSpan {tok, sp: _} =
+            env.string_reader.next_token();
+        assert_eq!(tok,token::LIT_CHAR('a' as u32));
+    }
+
 }

src/test/compile-fail/no-comment-balancing.rs renamed to src/test/run-pass/nested-block-comment.rs

@@ -8,19 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:
-
-/* This is a test to ensure that we do _not_ support nested/balanced comments. I know you might be
-   thinking "but nested comments are cool", and that would be a valid point, but they are also a
-   thing that would make our lexical syntax non-regular, and we do not want that to be true.
-
-   omitting-things at a higher level (tokens) should be done via token-trees / macros,
-   not comments.
+/* This test checks that nested comments are supported
 
    /*
-     fail here
+     This should not fail
    */
 */
 
-fn main() {
+pub fn main() {
 }