Do not allow identifiers that start with a dash.

This cleans up our previous fixes for a bug whereby Bison
discarded `.field' in `$-1.field'.  The previous fixes were less
restrictive about where a dash could appear in an identifier, but
the restrictions were hard to explain.  That bug was reported and
this final fix was originally suggested by Paul Hilfinger.  This
also fixes a remaining bug reported by Paul Eggert whereby Bison
parses `%token ID -123' as `%token ID - 123' and handles `-' as an
identifier.  Now, `-' cannot be an identifier.  Discussed in
threads beginning at
<http://lists.gnu.org/archive/html/bug-bison/2011-01/msg00000.html>,
<http://lists.gnu.org/archive/html/bug-bison/2011-01/msg00004.html>.
* NEWS (2.5): Update entry describing the dash extension to
grammar symbol names.  Also, move that entry before the named
references entry because the latter mentions the former.
* doc/bison.texinfo (Symbol): Update documentation for symbol
names.  As suggested by Paul Eggert, mention the effect of periods
and dashes on named references.
(Decl Summary): Update documentation for unquoted %define values,
which, as a side effect, can no longer start with dashes either.
* src/scan-code.l (id): Implement.
* src/scan-gram.l (id): Implement.
* tests/actions.at (Exotic Dollars): Extend test group to exercise
bug reported by Paul Hilfinger.
* tests/input.at (Symbols): Update test group, and extend to
exercise bug reported by Paul Eggert.
* tests/named-refs.at (Stray symbols in brackets): Update test
group.
($ or @ followed by . or -): Likewise.
* tests/regression.at (Invalid inputs): Likewise.
(cherry picked from commit 82f3355eaf)
This commit is contained in:
Joel E. Denny
2011-01-29 12:54:28 -05:00
parent 448dc38bc4
commit eb8c66bbda
9 changed files with 123 additions and 35 deletions

16
NEWS
View File

@@ -3,6 +3,14 @@ Bison News
* Changes in version 2.5 (????-??-??):
** Grammar symbol names can now contain non-initial dashes:
Consistently with directives (such as %error-verbose) and with
%define variables (e.g. push-pull), grammar symbol names may contain
dashes in any position except the beginning. This is a GNU
extension over POSIX Yacc. Thus, use of this extension is reported
by -Wyacc and rejected in Yacc mode (--yacc).
** Named references:
Historically, Yacc and Bison have supported positional references
@@ -98,14 +106,6 @@ Bison News
LAC is an experimental feature. More user feedback will help to
stabilize it.
** Grammar symbol names can now contain dashes:
Consistently with directives (such as %error-verbose) and variables
(e.g. push-pull), grammar symbol names may include dashes in any
position, similarly to periods and underscores. This is GNU
extension over POSIX Yacc whose use is reported by -Wyacc, and
rejected in Yacc mode (--yacc).
** %define improvements:
*** Can now be invoked via the command line: