Deprecate %pure-parser and add `%define api.pure'. Discussed starting

at
<http://lists.gnu.org/archive/html/bison-patches/2007-09/msg00006.html>.
* NEWS (2.3a+): Mention.
* data/bison.m4 (b4_pure_if): Don't define it here.
* data/c.m4 (b4_identification): Depend on individual skeletons to
define b4_pure_flag, b4_push_flag, or b4_pull_flag if they use the
values of the %define variables api.pure or api.push_pull.  Define
YYPURE, YYPUSH, and YYPULL accordingly.
* data/glr.c: Define b4_pure_if based on `%define api.pure' unless
glr.cc has already defined b4_pure_flag.
* data/push.c: Define b4_pure_if based on `%define api.pure'.
Remove YYPUSH and YYPULL since they're back in b4_identification again.
* data/yacc.c Define b4_pure_if based on `%define api.pure'.
* doc/bison.texinfo (Pure Decl): Update.
(Push Decl): Update.
(Decl Summary): Add api.pure to %define entry.
In %pure-parser entry, say it's deprecated and reference %define.
(Pure Calling): Update.
(Error Reporting): Update.
(C++ Scanner Interface): Update.
(How Can I Reset the Parser): Update.
(Table of Symbols): In %pure-parser entry, say it's deprecated and
reference %define.
* src/getargs.c (pure_parser): Remove global variable.
* src/getargs.h (pure_parser): Remove extern.
* src/output.c (prepare): Don't define pure_flag muscle.
* src/parse-gram.y (prologue_declaration): Implement %pure-parser as a
wrapper around `%define api.pure'.
* tests/calc.at (Simple LALR Calculator): Update.
(Simple GLR Calculator): Update.
* tests/cxx-type.at (GLR: Resolve ambiguity, pure, no locations):
Update.
(GLR: Resolve ambiguity, pure, locations): Update.
(GLR: Merge conflicting parses, pure, no locations): Update.
(GLR: Merge conflicting parses, pure, locations): Update.
* tests/glr-regression.at (Uninitialized location when reporting
ambiguity): Update
* tests/input.at (Unused %define api.pure): New test case.
* tests/local.at (_AT_BISON_OPTION_PUSHDEFS): Update definition for
AT_PURE_IF and AT_PURE_AND_LOC_IF.
* tests/push.at (Push Parsing: Memory Leak for Early Deletion): Update.

data/bison.m4

@@ -249,7 +249,6 @@ b4_define_flag_if([error_verbose])	# Whether error are verbose.
 b4_define_flag_if([glr])		# Whether a GLR parser is requested.
 b4_define_flag_if([locations])	        # Whether locations are tracked.
 b4_define_flag_if([nondeterministic])	# Whether conflicts should be handled.
-b4_define_flag_if([pure])	        # Whether the interface is pure.
 b4_define_flag_if([yacc])	        # Whether POSIX Yacc is emulated.
 
 

data/c.m4

@@ -28,22 +28,31 @@ m4_define([b4_comment], [/* m4_bpatsubst([$1], [
 
 # b4_identification
 # -----------------
+# Depends on individual skeletons to define b4_pure_flag, b4_push_flag, or
+# b4_pull_flag if they use the values of the %define variables api.pure or
+# api.push_pull.
 m4_define([b4_identification],
-[/* Identify Bison output.  */
-[#]define YYBISON 1
+[[/* Identify Bison output.  */
+#define YYBISON 1
 
 /* Bison version.  */
-[#]define YYBISON_VERSION "b4_version"
+#define YYBISON_VERSION "]b4_version["
 
 /* Skeleton name.  */
-[#]define YYSKELETON_NAME b4_skeleton
+#define YYSKELETON_NAME ]b4_skeleton[]m4_ifdef([b4_pure_flag], [[
 
 /* Pure parsers.  */
-[#]define YYPURE b4_pure_flag
+#define YYPURE ]b4_pure_flag])[]m4_ifdef([b4_push_flag], [[
+
+/* Push parsers.  */
+#define YYPUSH ]b4_push_flag])[]m4_ifdef([b4_pull_flag], [[
+
+/* Pull parsers.  */
+#define YYPULL ]b4_pull_flag])[
 
 /* Using locations.  */
-[#]define YYLSP_NEEDED b4_locations_flag
-])
+#define YYLSP_NEEDED ]b4_locations_flag[
+]])
 
 
 ## ---------------- ##

data/glr.c

@@ -34,6 +34,13 @@ m4_define_default([b4_stack_depth_init],  [200])
 ## Pure/impure interfaces.  ##
 ## ------------------------ ##
 
+b4_define_flag_if([pure])
+# If glr.cc is including this file and thus has already set b4_pure_flag, don't
+# change the value of b4_pure_flag, and don't record a use of api.pure.
+m4_ifndef([b4_pure_flag],
+[b4_percent_define_default([[api.pure]], [[false]])
+ m4_define([b4_pure_flag],
+           [b4_percent_define_flag_if([[api.pure]], [[1]], [[0]])])])
 
 # b4_user_formals
 # ---------------

data/push.c

@@ -51,6 +51,10 @@ m4_define_default([b4_stack_depth_init],  [200])
 ## Pure/impure interfaces.  ##
 ## ------------------------ ##
 
+b4_percent_define_default([[api.pure]], [[false]])
+b4_define_flag_if([pure])
+m4_define([b4_pure_flag],
+          [b4_percent_define_flag_if([[api.pure]], [[1]], [[0]])])
 
 # b4_yacc_pure_if(IF-TRUE, IF-FALSE)
 # ----------------------------------
@@ -163,14 +167,9 @@ 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[
-/* Push parsers.  */
-#define YYPUSH ]b4_push_flag[
+]b4_identification
 
-/* Pull parsers.  */
-#define YYPULL ]b4_pull_flag[
-
-]b4_percent_code_get([[top]])[]dnl
+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

data/yacc.c

@@ -37,6 +37,10 @@ m4_define_default([b4_stack_depth_init],  [200])
 ## Pure/impure interfaces.  ##
 ## ------------------------ ##
 
+b4_percent_define_default([[api.pure]], [[false]])
+b4_define_flag_if([pure])
+m4_define([b4_pure_flag],
+          [b4_percent_define_flag_if([[api.pure]], [[1]], [[0]])])
 
 # b4_yacc_pure_if(IF-TRUE, IF-FALSE)
 # ----------------------------------