maint: Valgrind on OS X.

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

diff --git a/data/c++.m4 b/data/c++.m4
index 81ad14f5964eaf8c1017d5d39346e01a908c1da7..45c4ddaf1f81331cd5e253a03320216398ee5473 100644 (file)
--- a/data/c++.m4
+++ b/data/c++.m4
@@ -2,8 +2,7 @@
 
 # C++ skeleton for Bison
 
-# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation,
-# Inc.
+# Copyright (C) 2002-2012 Free Software Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -26,7 +25,12 @@ m4_include(b4_pkgdatadir/[c.m4])
 
 # Default parser class name.
 b4_percent_define_default([[parser_class_name]], [[parser]])
-b4_percent_define_default([[location_type]], [[location]])
+
+# Don't do that so that we remember whether we're using a user
+# request, or the default value.
+#
+# b4_percent_define_default([[location_type]], [[location]])
+
 b4_percent_define_default([[filename_type]], [[std::string]])
 b4_percent_define_default([[namespace]], m4_defn([b4_prefix]))
 b4_percent_define_default([[global_tokens_and_yystype]], [[false]])
@@ -35,6 +39,51 @@ 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.
@@ -48,6 +97,8 @@ m4_map_sep([     b4_token_enum], [,
 ])
 
 
+
+
 ## ----------------- ##
 ## Semantic Values.  ##
 ## ----------------- ##
@@ -123,3 +174,32 @@ m4_define([b4_cc_var_decls],
 ], [$@])])
 m4_define([b4_cc_var_decl],
          [    $1;])
+
+
+## ---------##
+## Values.  ##
+## ---------##
+
+# b4_yylloc_default_define
+# ------------------------
+# Define YYLLOC_DEFAULT.
+m4_define([b4_yylloc_default_define],
+[[/* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
+   If N is 0, then set CURRENT to the empty location which ends
+   the previous symbol: RHS[0] (always defined).  */
+
+# ifndef YYLLOC_DEFAULT
+#  define YYLLOC_DEFAULT(Current, Rhs, N)                               \
+    do                                                                  \
+      if (N)                                                            \
+        {                                                               \
+          (Current).begin  = YYRHSLOC (Rhs, 1).begin;                   \
+          (Current).end    = YYRHSLOC (Rhs, N).end;                     \
+        }                                                               \
+      else                                                              \
+        {                                                               \
+          (Current).begin = (Current).end = YYRHSLOC (Rhs, 0).end;      \
+        }                                                               \
+    while (/*CONSTCOND*/ false)
+# endif
+]])