c++: fix a comment

[bison.git] / data / bison.m4

diff --git a/data/bison.m4 b/data/bison.m4
index 37bc012f58f9f1822cbba76389ccbc1255b751ce..42a548dae0617a44b2259e209f037a9ffbf22285 100644 (file)
--- a/data/bison.m4
+++ b/data/bison.m4
@@ -186,21 +186,6 @@ m4_define([b4_fatal_at],
 m4_exit(1)])
 
 
 m4_exit(1)])
 
 

-## ---------------- ##
-## Default values.  ##
-## ---------------- ##
-
-# m4_define_default([b4_lex_param], [])   dnl breaks other skeletons
-m4_define_default([b4_pre_prologue], [])
-m4_define_default([b4_post_prologue], [])
-m4_define_default([b4_epilogue], [])
-m4_define_default([b4_parse_param], [])
-
-# The initial column and line.
-m4_define_default([b4_location_initial_column], [1])
-m4_define_default([b4_location_initial_line],   [1])
-
-

 ## ------------ ##
 ## Data Types.  ##
 ## ------------ ##
 ## ------------ ##
 ## Data Types.  ##
 ## ------------ ##


@@ -221,23 +206,23 @@ m4_define([b4_subtract],
            [m4_eval([$1 - $2])],
            [($1) - ($2)])])
 
            [m4_eval([$1 - $2])],
            [($1) - ($2)])])
 

-# b4_args(ARG1, ...)
-# _b4_args(ARG1, ...)
+# b4_join(ARG1, ...)
+# _b4_join(ARG1, ...)

 # -------------------
 # Join with comma, skipping empty arguments.
 # -------------------
 # Join with comma, skipping empty arguments.

-# b4_args calls itself recursively until it sees the first non-empty
-# argument, then calls _b4_args which prepends each non-empty argument
+# b4_join calls itself recursively until it sees the first non-empty
+# argument, then calls _b4_join which prepends each non-empty argument

 # with a comma.
 # with a comma.

-m4_define([b4_args],
+m4_define([b4_join],

 [m4_if([$#$1],
        [1], [],
        [m4_ifval([$1],
                  [$1[]_$0(m4_shift($@))],
                  [$0(m4_shift($@))])])])
 
 [m4_if([$#$1],
        [1], [],
        [m4_ifval([$1],
                  [$1[]_$0(m4_shift($@))],
                  [$0(m4_shift($@))])])])
 

-# _b4_args(ARGS1, ...)
+# _b4_join(ARGS1, ...)

 # --------------------
 # --------------------

-m4_define([_b4_args],
+m4_define([_b4_join],

 [m4_if([$#$1],
        [1], [],
        [m4_ifval([$1], [, $1])[]$0(m4_shift($@))])])
 [m4_if([$#$1],
        [1], [],
        [m4_ifval([$1], [, $1])[]$0(m4_shift($@))])])


@@ -317,9 +302,9 @@ m4_define([b4_define_flag_if],
 
 # _b4_define_flag_if($1, $2, FLAG)
 # --------------------------------
 
 # _b4_define_flag_if($1, $2, FLAG)
 # --------------------------------

-# This macro works around the impossibility to define macros
-# inside macros, because issuing `[$1]' is not possible in M4 :(.
-# This sucks hard, GNU M4 should really provide M5 like $$1.
+# Work around the impossibility to define macros inside macros,
+# because issuing `[$1]' is not possible in M4.  GNU M4 should provide
+# $$1 a la M5/TeX.

 m4_define([_b4_define_flag_if],
 [m4_if([$1$2], $[1]$[2], [],
        [m4_fatal([$0: Invalid arguments: $@])])dnl
 m4_define([_b4_define_flag_if],
 [m4_if([$1$2], $[1]$[2], [],
        [m4_fatal([$0: Invalid arguments: $@])])dnl


@@ -333,6 +318,7 @@ m4_define([b4_$3_if],
 b4_define_flag_if([defines])            # Whether headers are requested.
 b4_define_flag_if([glr])                # Whether a GLR parser is requested.
 b4_define_flag_if([nondeterministic])   # Whether conflicts should be handled.
 b4_define_flag_if([defines])            # Whether headers are requested.
 b4_define_flag_if([glr])                # Whether a GLR parser is requested.
 b4_define_flag_if([nondeterministic])   # Whether conflicts should be handled.

+b4_define_flag_if([token_table])        # Whether yytoken_table is demanded.

 b4_define_flag_if([yacc])               # Whether POSIX Yacc is emulated.
 
 
 b4_define_flag_if([yacc])               # Whether POSIX Yacc is emulated.
 
 


@@ -340,6 +326,13 @@ b4_define_flag_if([yacc])               # Whether POSIX Yacc is emulated.
 ## Symbols.  ##
 ## --------- ##
 
 ## Symbols.  ##
 ## --------- ##
 

+# In order to unify the handling of the various aspects of symbols
+# (tag, type_name, whether terminal, etc.), bison.exe defines one
+# macro per (token, field), where field can has_id, id, etc.: see
+# src/output.c:prepare_symbols_definitions().
+#
+# The following macros provide access to these values.
+

 # b4_symbol_(NUM, FIELD)
 # ----------------------
 # Recover a FIELD about symbol #NUM.  Thanks to m4_indir, fails if
 # b4_symbol_(NUM, FIELD)
 # ----------------------
 # Recover a FIELD about symbol #NUM.  Thanks to m4_indir, fails if


@@ -383,19 +376,17 @@ m4_define([b4_symbol_action_location],
 # Same as in C, but using references instead of pointers.
 m4_define([b4_symbol_action],
 [b4_symbol_if([$1], [has_$2],
 # Same as in C, but using references instead of pointers.
 m4_define([b4_symbol_action],
 [b4_symbol_if([$1], [has_$2],

-[m4_pushdef([b4_dollar_dollar],
-    [b4_symbol_value([(*yyvaluep)],
-                     b4_symbol_if([$1], [has_type],
-                                  [b4_symbol([$1], [type])]))])dnl
-m4_pushdef([b4_at_dollar], [(*yylocationp)])dnl
-      b4_symbol_case_([$1])
+[b4_dollar_pushdef([(*yyvaluep)],
+                   b4_symbol_if([$1], [has_type],
+                                [m4_dquote(b4_symbol([$1], [type]))]),
+                   [(*yylocationp)])dnl
+      b4_symbol_case_([$1])[]dnl

 b4_syncline([b4_symbol([$1], [$2_line])], ["b4_symbol([$1], [$2_file])"])
         b4_symbol([$1], [$2])
 b4_syncline([@oline@], [@ofile@])
         break;
 
 b4_syncline([b4_symbol([$1], [$2_line])], ["b4_symbol([$1], [$2_file])"])
         b4_symbol([$1], [$2])
 b4_syncline([@oline@], [@ofile@])
         break;
 

-m4_popdef([b4_at_dollar])dnl
-m4_popdef([b4_dollar_dollar])dnl
+b4_dollar_popdef[]dnl

 ])])
 
 
 ])])
 
 


@@ -420,6 +411,45 @@ m4_define([b4_symbol_case_],
 m4_define([b4_symbol_foreach],
           [m4_map([$1], m4_defn([b4_symbol_numbers]))])
 
 m4_define([b4_symbol_foreach],
           [m4_map([$1], m4_defn([b4_symbol_numbers]))])
 

+# b4_symbol_map(MACRO)
+# --------------------
+# Return a list (possibly empty elements) of MACRO invoked for each
+# SYMBOL-NUM.
+m4_define([b4_symbol_map],
+[m4_map_args_sep([$1(], [)], [,], b4_symbol_numbers)])
+
+
+# b4_token_visible_if(NUM, IF-TRUE, IF-FALSE)
+# -------------------------------------------
+# Whether NUM denotes a token that has an exported definition (i.e.,
+# shows in enum yytokentype).
+m4_define([b4_token_visible_if],
+[b4_symbol_if([$1], [is_token],
+              [b4_symbol_if([$1], [has_id], [$2], [$3])],
+              [$3])])
+
+# b4_token_has_definition(NUM)
+# ----------------------------
+# 1 if NUM is visible, nothing otherwise.
+m4_define([b4_token_has_definition],
+[b4_token_visible_if([$1], [1])])
+
+# b4_any_token_visible_if([IF-TRUE], [IF-FALSE])
+# ----------------------------------------------
+# Whether there is a token that needs to be defined.
+m4_define([b4_any_token_visible_if],
+[m4_ifval(b4_symbol_foreach([b4_token_has_definition]),
+          [$1], [$2])])
+
+
+# b4_token_format(FORMAT, NUM)
+# ----------------------------
+m4_define([b4_token_format],
+[b4_token_visible_if([$2],
+[m4_quote(m4_format([$1],
+                     [b4_symbol([$2], [id])],
+                     [b4_symbol([$2], [user_number])]))])])
+

 
 ## ------- ##
 ## Types.  ##
 
 ## ------- ##
 ## Types.  ##


@@ -802,6 +832,9 @@ m4_define([b4_error_verbose_flag],
                    [verbose], [[1]])])
 b4_define_flag_if([error_verbose])
 
                    [verbose], [[1]])])
 b4_define_flag_if([error_verbose])
 

+# yytoken_table is needed to support verbose errors.
+b4_error_verbose_if([m4_define([b4_token_table_flag], [1])])
+

 
 ## ----------------------------------------------------------- ##
 ## After processing the skeletons, check that all the user's   ##
 
 ## ----------------------------------------------------------- ##
 ## After processing the skeletons, check that all the user's   ##


@@ -818,3 +851,26 @@ m4_wrap_lifo([
 b4_check_user_names_wrap([[define]], [[variable]])
 b4_check_user_names_wrap([[code]], [[qualifier]])
 ])
 b4_check_user_names_wrap([[define]], [[variable]])
 b4_check_user_names_wrap([[code]], [[qualifier]])
 ])

+
+
+## ---------------- ##
+## Default values.  ##
+## ---------------- ##
+
+# m4_define_default([b4_lex_param], [])   dnl breaks other skeletons
+m4_define_default([b4_pre_prologue], [])
+m4_define_default([b4_post_prologue], [])
+m4_define_default([b4_epilogue], [])
+m4_define_default([b4_parse_param], [])
+
+# The initial column and line.
+m4_define_default([b4_location_initial_column], [1])
+m4_define_default([b4_location_initial_line],   [1])
+
+# Sanity checks.
+b4_percent_define_ifdef([api.prefix],
+[m4_ifdef([b4_prefix],
+[b4_complain_at(b4_percent_define_get_loc([api.prefix]),
+                [['%s' and '%s' cannot be used together]],
+                [%name-prefix],
+                [%define api.prefix])])])