Remove parser::rhs_number_type.

[bison.git] / data / c++.m4

diff --git a/data/c++.m4 b/data/c++.m4
index 81ad14f5964eaf8c1017d5d39346e01a908c1da7..ba17dff1d97175ddb85a76a89a9af628988f30d7 100644 (file)
--- a/data/c++.m4
+++ b/data/c++.m4
@@ -2,7 +2,7 @@
 
 # C++ skeleton for Bison
 
-# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation,
+# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation,
 # Inc.
 
 # This program is free software: you can redistribute it and/or modify
@@ -35,6 +35,51 @@ b4_percent_define_default([[define_location_comparison]],
                                  [std::string], [[true]], [[false]])])
 
 
+## ----------- ##
+## Namespace.  ##
+## ----------- ##
+
+m4_define([b4_namespace_ref], [b4_percent_define_get([[namespace]])])
+
+# Don't permit an empty b4_namespace_ref.  Any `::parser::foo' appended to it
+# would compile as an absolute reference with `parser' in the global namespace.
+# b4_namespace_open would open an anonymous namespace and thus establish
+# internal linkage.  This would compile.  However, it's cryptic, and internal
+# linkage for the parser would be specified in all translation units that
+# include the header, which is always generated.  If we ever need to permit
+# internal linkage somehow, surely we can find a cleaner approach.
+m4_if(m4_bregexp(b4_namespace_ref, [^[  ]*$]), [-1], [],
+[b4_complain_at(b4_percent_define_get_loc([[namespace]]),
+                [[namespace reference is empty]])])
+
+# Instead of assuming the C++ compiler will do it, Bison should reject any
+# invalid b4_namepsace_ref that would be converted to a valid
+# b4_namespace_open.  The problem is that Bison doesn't always output
+# b4_namespace_ref to uncommented code but should reserve the ability to do so
+# in future releases without risking breaking any existing user grammars.
+# Specifically, don't allow empty names as b4_namespace_open would just convert
+# those into anonymous namespaces, and that might tempt some users.
+m4_if(m4_bregexp(b4_namespace_ref, [::[         ]*::]), [-1], [],
+[b4_complain_at(b4_percent_define_get_loc([[namespace]]),
+                [[namespace reference has consecutive "::"]])])
+m4_if(m4_bregexp(b4_namespace_ref, [::[         ]*$]), [-1], [],
+[b4_complain_at(b4_percent_define_get_loc([[namespace]]),
+                [[namespace reference has a trailing "::"]])])
+
+m4_define([b4_namespace_open],
+[b4_user_code([b4_percent_define_get_syncline([[namespace]])
+[namespace ]m4_bpatsubst(m4_dquote(m4_bpatsubst(m4_dquote(b4_namespace_ref),
+                                                [^\(.\)[        ]*::], [\1])),
+                         [::], [ { namespace ])[ {]])])
+
+m4_define([b4_namespace_close],
+[b4_user_code([b4_percent_define_get_syncline([[namespace]])
+m4_bpatsubst(m4_dquote(m4_bpatsubst(m4_dquote(b4_namespace_ref),
+                                    [^\(.\)[    ]*\(::\)?\([^][:]\|:[^][:]\)*],
+                                    [\1])),
+             [::\([^][:]\|:[^][:]\)*], [} ])[} // ]b4_namespace_ref])])
+
+
 # b4_token_enums(LIST-OF-PAIRS-TOKEN-NAME-TOKEN-NUMBER)
 # -----------------------------------------------------
 # Output the definition of the tokens as enums.
@@ -52,12 +97,17 @@ m4_map_sep([     b4_token_enum], [,
 ## Semantic Values.  ##
 ## ----------------- ##
 
+# b4_variant_if([IF-VARIANT-ARE-USED], [IF-NOT])
+# ----------------------------------------------
+m4_define([b4_variant_if],
+[b4_percent_define_ifdef([[variant]], [$1], [$2])])
+
 
 # b4_lhs_value([TYPE])
 # --------------------
 # Expansion of $<TYPE>$.
 m4_define([b4_lhs_value],
-[(yyval[]m4_ifval([$1], [.$1]))])
+[b4_symbol_value([yyval], [$1])])
 
 
 # b4_rhs_value(RULE-LENGTH, NUM, [TYPE])
@@ -65,7 +115,8 @@ m4_define([b4_lhs_value],
 # Expansion of $<TYPE>NUM, where the current rule has RULE-LENGTH
 # symbols on RHS.
 m4_define([b4_rhs_value],
-[(yysemantic_stack_@{($1) - ($2)@}m4_ifval([$3], [.$3]))])
+[b4_symbol_value([yysemantic_stack_@{($1) - ($2)@}], [$3])])
+
 
 # b4_lhs_location()
 # -----------------