For push mode, convert yyparse from a macro to a function, invoke yylex

instead of passing a yylexp argument to yypull_parse, and don't
generate yypull_parse or yyparse unless %push-pull-parser is declared.
Discussed starting at
<http://lists.gnu.org/archive/html/bison-patches/2006-12/msg00163.html>.
* data/bison.m4 (b4_pull_if): New.
* data/c.m4 (b4_identification): Define YYPULL similar to YYPUSH.
* data/push.c: Improve M4 quoting a little.
(b4_generate_macro_args, b4_parenthesize): Remove.
(yyparse): If there's a b4_prefix, #define this to b4_prefix[parse]
any time a pull parser is requested.
Don't #define this as a wrapper around yypull_parse.  Instead, when
both push and pull are requested, make it a function that does that
same thing.
(yypull_parse): If there's a b4_prefix, #define this to
b4_prefix[pull_parse] when both push and pull are requested.
Don't define this as a function unless both push and pull are
requested.
Remove the yylexp argument and hard-code yylex invocation instead.
* etc/bench.pl.in (bench_grammar): Use %push-pull-parser instead of
%push-parser.
* src/getargs.c (pull_parser): New global initialized to true.
* getargs.h (pull_parser): extern it.
* src/output.c (prepare): Insert pull_flag muscle.
* src/parse-gram.y (PERCENT_PUSH_PULL_PARSER): New token.
(prologue_declaration): Set both push_parser and pull_parser = true for
%push-pull-parser.  Set push_parser = true and pull_parser = false for
%push-parser.
* src/scan-gram.l: Don't accept %push_parser as an alternative to
%push-parser since there's no backward-compatibility concern here.
Scan %push-pull-parser.
* tests/calc.at (Simple LALR(1) Calculator): Use %push-pull-parser
instead of %push-parser.
* tests/headers.at (export YYLTYPE): Make yylex static, and don't
prototype it in the module that calls yyparse.
* tests/input.at (Torturing the Scanner): Likewise.
* tests/local.at (AT_PUSH_IF): Check for %push-pull-parser as well.

src/parse-gram.h

@@ -78,27 +78,28 @@
      PERCENT_PROVIDES = 292,
      PERCENT_PURE_PARSER = 293,
      PERCENT_PUSH_PARSER = 294,
-     PERCENT_REQUIRE = 295,
-     PERCENT_REQUIRES = 296,
-     PERCENT_SKELETON = 297,
-     PERCENT_START = 298,
-     PERCENT_TOKEN_TABLE = 299,
-     PERCENT_VERBOSE = 300,
-     PERCENT_YACC = 301,
-     BRACED_CODE = 302,
-     CHAR = 303,
-     EPILOGUE = 304,
-     EQUAL = 305,
-     ID = 306,
-     ID_COLON = 307,
-     PERCENT_PERCENT = 308,
-     PIPE = 309,
-     PROLOGUE = 310,
-     SEMICOLON = 311,
-     TYPE = 312,
-     TYPE_TAG_ANY = 313,
-     TYPE_TAG_NONE = 314,
-     PERCENT_UNION = 315
+     PERCENT_PUSH_PULL_PARSER = 295,
+     PERCENT_REQUIRE = 296,
+     PERCENT_REQUIRES = 297,
+     PERCENT_SKELETON = 298,
+     PERCENT_START = 299,
+     PERCENT_TOKEN_TABLE = 300,
+     PERCENT_VERBOSE = 301,
+     PERCENT_YACC = 302,
+     BRACED_CODE = 303,
+     CHAR = 304,
+     EPILOGUE = 305,
+     EQUAL = 306,
+     ID = 307,
+     ID_COLON = 308,
+     PERCENT_PERCENT = 309,
+     PIPE = 310,
+     PROLOGUE = 311,
+     SEMICOLON = 312,
+     TYPE = 313,
+     TYPE_TAG_ANY = 314,
+     TYPE_TAG_NONE = 315,
+     PERCENT_UNION = 316
    };
 #endif
 /* Tokens.  */
@@ -140,27 +141,28 @@
 #define PERCENT_PROVIDES 292
 #define PERCENT_PURE_PARSER 293
 #define PERCENT_PUSH_PARSER 294
-#define PERCENT_REQUIRE 295
-#define PERCENT_REQUIRES 296
-#define PERCENT_SKELETON 297
-#define PERCENT_START 298
-#define PERCENT_TOKEN_TABLE 299
-#define PERCENT_VERBOSE 300
-#define PERCENT_YACC 301
-#define BRACED_CODE 302
-#define CHAR 303
-#define EPILOGUE 304
-#define EQUAL 305
-#define ID 306
-#define ID_COLON 307
-#define PERCENT_PERCENT 308
-#define PIPE 309
-#define PROLOGUE 310
-#define SEMICOLON 311
-#define TYPE 312
-#define TYPE_TAG_ANY 313
-#define TYPE_TAG_NONE 314
-#define PERCENT_UNION 315
+#define PERCENT_PUSH_PULL_PARSER 295
+#define PERCENT_REQUIRE 296
+#define PERCENT_REQUIRES 297
+#define PERCENT_SKELETON 298
+#define PERCENT_START 299
+#define PERCENT_TOKEN_TABLE 300
+#define PERCENT_VERBOSE 301
+#define PERCENT_YACC 302
+#define BRACED_CODE 303
+#define CHAR 304
+#define EPILOGUE 305
+#define EQUAL 306
+#define ID 307
+#define ID_COLON 308
+#define PERCENT_PERCENT 309
+#define PIPE 310
+#define PROLOGUE 311
+#define SEMICOLON 312
+#define TYPE 313
+#define TYPE_TAG_ANY 314
+#define TYPE_TAG_NONE 315
+#define PERCENT_UNION 316
 
 
 
@@ -182,7 +184,7 @@ typedef union YYSTYPE
 }
 
 /* Line 1535 of yacc.c  */
-#line 186 "parse-gram.h"
+#line 188 "parse-gram.h"
 	YYSTYPE;
 # define YYSTYPE_IS_TRIVIAL 1
 # define yystype YYSTYPE /* obsolescent; will be withdrawn */