Replace %push-parser' and %push-pull-parser' with

`%define push_pull "push"' and `%define push_pull "both"'.
`%define push_pull "pull"' is the default.
* doc/bison.texinfo (Push Decl, Push Parser Function,
Pull Parser Function, Parser Create Function, Parser Delete Function):
Update declarations.
(Decl Summary, Table of Symbols): Replace %push-parser and
%push-pull-parser entries with a %define push_pull entry.
* data/bison.m4 (b4_percent_define_check_values): New macro.
(b4_pull_if, b4_push_if, b4_use_push_for_pull_if): Move these
definitions...
* data/c.m4 (b4_identification): ... and the YYPUSH and YYPULL cpp
definitions...
* data/push.c: ... to here and compute them from the value of the
%define variable push_pull.
* data/c-skel.m4: Instead of choosing the push.c skeleton for push
parsing requests here...
* data/yacc.c: ... hack this to switch to push.c any time
b4_use_push_pull_flag or the %define variable push_pull is set.  This
will go away when we mv push.c yacc.c.
* data/c++-skel.m4, data/glr.c, data/java-skel.m4: Don't report that
push parsing is not supported since unused %define variables are
reported anyway.
* src/getargs.c, src/getargs.h (pull_parser, push_parser): Remove.
* src/muscle_tab.h (muscle_percent_define_check_values): Update
comments for consistency with b4_percent_define_check_values.
* src/output.c (prepare): Don't insert b4_pull_flag and b4_push_flag
muscles.
* src/parse-gram.y (PERCENT_PUSH_PARSER, PERCENT_PUSH_PULL_PARSER):
Remove.
(prologue_declaration): Remove %push-parser and %push-pull-parser
rules.
* src/scan-gram.l (%push-parser, %push-pull-parser): Remove rules.
* tests/calc.at: Update declarations.
* tests/input.at (%define enum variables): New test case.
* tests/push.at (Push Parsing: Memory Leak for Early Deletion): Update
declaration.
(Push Parsing: Multiple impure instances): Update declaration.
(Push Parsing: Unsupported Skeletons): New test case.
* tests/torture.at (Exploding the Stack Size with Alloca): Update
declaration.
(Exploding the Stack Size with Malloc): Update declaration.

data/push.c

@@ -18,17 +18,22 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+# Check the value of %define push_pull.
+b4_percent_define_default([[push_pull]], [[pull]])
+b4_percent_define_check_values([[[[push_pull]], [[pull]], [[push]], [[both]]]])
+b4_define_flag_if([pull]) m4_define([b4_pull_flag], [[1]])
+b4_define_flag_if([push]) m4_define([b4_push_flag], [[1]])
+m4_case(b4_percent_define_get([[push_pull]]),
+        [pull], [m4_define([b4_push_flag], [[0]])],
+        [push], [m4_define([b4_pull_flag], [[0]])])
+
 # Handle BISON_USE_PUSH_FOR_PULL for the test suite.  So that push parsing
 # tests function as written, don't let BISON_USE_PUSH_FOR_PULL modify Bison's
 # behavior at all when push parsing is already requested.
+b4_define_flag_if([use_push_for_pull])
 b4_use_push_for_pull_if([
-  b4_push_if([
-    m4_define([b4_use_push_for_pull_flag], [[0]])
-    b4_define_flag_if([use_push_for_pull])
-  ], [
-    m4_define([b4_push_flag], [[1]])
-    b4_define_flag_if([push])
-  ])])
+  b4_push_if([m4_define([b4_use_push_for_pull_flag], [[0]])],
+             [m4_define([b4_push_flag], [[1]])])])
 
 m4_include(b4_pkgdatadir/[c.m4])
 
@@ -157,8 +162,14 @@ b4_copyright([Skeleton implementation for Bison's Yacc-like parsers in C],dnl '
    define necessary library symbols; they are noted "INFRINGES ON
    USER NAME SPACE" below.  */
 
-]b4_identification
-b4_percent_code_get([[top]])[]dnl
+]b4_identification[
+/* Push parsers.  */
+#define YYPUSH ]b4_push_flag[
+
+/* Pull parsers.  */
+#define YYPULL ]b4_pull_flag[
+
+]b4_percent_code_get([[top]])[]dnl
 m4_if(b4_prefix, [yy], [],
 [[/* Substitute the variable and function names.  */
 ]b4_pull_if([[#define yyparse         ]b4_prefix[parse