Don't pass C-only options to g++.

Fix YYFILL in GLR parsers to conform to the C standard.
Fix infinite loops in yacc.c, and add a test case.

diff --git a/ChangeLog b/ChangeLog
index 90b5574..cb9186f 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,56 @@
+2003-06-01  Paul Eggert  <eggert@twinsun.com>
+
+       Don't pass C-only warning optins (e.g., -Wmissing-declarations)
+       to g++, as GCC 3.3 complains if you do it.
+       * configure.ac (WARNING_CXXFLAGS): New subst.  Set it to
+       everything that WARNING_CFLAGS has, except omit warnings
+       not suitable for C++.
+       (AC_PROG_CXX): Use this instead of AC_CHECK_PROGS([CXX], [g++]).
+       * tests/atlocal.in (CXXFLAGS): New var.
+       * tests/local.at (AT_COMPILE_CXX): Use it instead of CFLAGS.
+
+       Fix a GLR parser bug I reported in February; see
+       <http://mail.gnu.org/archive/html/bison-patches/2003-02/msg00008.html>.
+       The problem was that GLR parsers did not conform to the C standard,
+       because actions like { $1 = $2 + $3; } expanded to expressions
+       that invoked YYFILL in separate subexpressions, and YYFILL assigned
+       to a local variable.  The C standard says that expressions
+       like (var = f ()) + (var = f ()) have undefined behavior.
+       Another problem was that GCC sometimes issues warnings that
+       yyfill and its parameters are unused.
+
+       * data/glr.c (yyfillin): Renamed from the old yyfill.  Mark
+       as possibly unused.
+       (yyfill): New function.
+       (YYFILL): Use it.
+       (yyuserAction): Change type of yynormal to bool, so that it matches
+       the new yyfill signature.  Mark it as possibly unused.
+
+
+       Follow up on a bug I reported in February, where a Bison-generated
+       parser can loop.  Provide a test case and a fix for yacc.c.  I
+       don't have a fix for lalr1.cc or for glr.c, unfortunately.
+       The original bug report is in:
+       <http://mail.gnu.org/archive/html/bison-patches/2003-02/msg00044.html>
+
+       * data/yacc.c (YYERROR): Now just 'goto yyerrorlab', since the
+       macro's size was becoming unwieldy.
+       (yyerrlab): Do not discard an empty lookahead symbol, as this
+       might destroy garbage.
+       (yyerrorlab): New label, with the old contents of YYERROR,
+       plus the following change: pop the stack of rhs corresponding
+       to the production that invoked YYERROR.  That is how Yacc
+       behaves, and POSIX requires this behavior.
+       (yyerrlab1): Use YYPOPSTACK instead of its definiens.
+       * tests/calc.at (_AT_DATA_CALC_Y): Include unistd.h if available.
+       Define 'alarm' to do nothing if unistd.h is not available.
+       Add a new rule "exp: '-' error;" to test the above change to
+       data/yacc.c.  Use 'alarm' to abort any test taking longer than
+       10 seconds, as it's probably looping.
+       (AT_CHECK_CALC): Test recovery from error in new grammar rule.
+       Also, the new yacc.c generates two fewer diagnostics for an
+       existing test.
+
 2003-05-24  Paul Eggert  <eggert@twinsun.com>
 
        * data/glr.c (YYSTACKEXPANDABLE): Do not evaluate
@@ -7,7 +60,7 @@
        -ansi -Wall -gall).
        * data/yacc.c (union yyalloc): Likewise.
        (YYCOPY): Do not evaluate __GNUC__ unless it is defined.
-       
+
        Switch from 'int' to 'bool' where that makes sense.
 
        * lib/abitset.c (abitset_test, abitset_empty_p, abitset_equal_p,