Parameterize the extraction of semantic values.

[bison.git] / data / c.m4

diff --git a/data/c.m4 b/data/c.m4
index 955edee6f7c875b3a4240c2729f90ed461ac07ec..66d4f6d23aafc936f2a1dc14143131680d39553f 100644 (file)
--- a/data/c.m4
+++ b/data/c.m4
@@ -1,7 +1,8 @@
                                                             -*- Autoconf -*-
 
 # C M4 Macros for Bison.
-# Copyright (C) 2002, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+# Copyright (C) 2002, 2004, 2005, 2006, 2007, 2008 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
@@ -28,28 +29,31 @@ 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
+#define YYPUSH ]b4_push_flag])[]m4_ifdef([b4_pull_flag], [[
 
 /* Pull parsers.  */
-[#]define YYPULL b4_pull_flag
+#define YYPULL ]b4_pull_flag])[
 
 /* Using locations.  */
-[#]define YYLSP_NEEDED b4_locations_flag
-])
+#define YYLSP_NEEDED ]b4_locations_flag[
+]])
 
 
 ## ---------------- ##
@@ -86,7 +90,7 @@ b4_parse_param)
 # the formal name to FORMAL, and evaluating the BODY.
 m4_define([b4_parse_param_for],
 [m4_foreach([$1_$2], m4_defn([b4_parse_param]),
-[m4_pushdef([$1], m4_fst($1_$2))dnl
+[m4_pushdef([$1], m4_unquote(m4_car($1_$2)))dnl
 m4_pushdef([$2], m4_shift($1_$2))dnl
 $3[]dnl
 m4_popdef([$2])dnl
@@ -129,6 +133,8 @@ m4_define([b4_int_type],
 m4_define([b4_int_type_for],
 [b4_int_type($1_min, $1_max)])
 
+
+
 ## ---------##
 ## Values.  ##
 ## ---------##
@@ -140,6 +146,8 @@ m4_define([b4_int_type_for],
 m4_define([b4_null], [0])
 
 
+
+
 ## ------------------------- ##
 ## Assigning token numbers.  ##
 ## ------------------------- ##
@@ -156,7 +164,7 @@ m4_define([b4_token_define],
 # -------------------------------------------------------
 # Output the definition of the tokens (if there are) as #defines.
 m4_define([b4_token_defines],
-[m4_if([$@], [[]], [],
+[m4_if([$#$1], [1], [],
 [/* Tokens.  */
 m4_map([b4_token_define], [$@])])
 ])
@@ -173,7 +181,7 @@ m4_define([b4_token_enum],
 # -----------------------------------------------------
 # Output the definition of the tokens (if there are) as enums.
 m4_define([b4_token_enums],
-[m4_if([$@], [[]], [],
+[m4_if([$#$1], [1], [],
 [/* Tokens.  */
 #ifndef YYTOKENTYPE
 # define YYTOKENTYPE
@@ -197,6 +205,21 @@ m4_define([b4_token_enums_defines],
 ])
 
 
+## ----------------- ##
+## Semantic Values.  ##
+## ----------------- ##
+
+
+# b4_symbol_value(VAL, [TYPE])
+# ----------------------------
+# Given a semantic value VAL ($$, $1 etc.), extract its value of type
+# TYPE if TYPE is given, otherwise just return VAL.  The result can be
+# used safetly, it is put in parens to avoid nasty precedence issues.
+# TYPE is *not* put in braces, provide some if needed.
+m4_define([b4_symbol_value],
+[($1[]m4_ifval([$2], [.$2]))])
+
+
 
 ## --------------------------------------------- ##
 ## Defining C functions in both K&R and ANSI-C.  ##
@@ -225,8 +248,8 @@ m4_define([b4_c_function_def],
 b4_c_ansi_function_def($@)
 #else
 $2
-$1 (b4_c_knr_formal_names(m4_shiftn(2, $@)))
-b4_c_knr_formal_decls(m4_shiftn(2, $@))
+$1 (b4_c_knr_formal_names(m4_shift2($@)))
+b4_c_knr_formal_decls(m4_shift2($@))
 #endif[]dnl
 ])
 
@@ -236,7 +259,7 @@ b4_c_knr_formal_decls(m4_shiftn(2, $@))
 # Declare the function NAME in ANSI.
 m4_define([b4_c_ansi_function_def],
 [$2
-$1 (b4_c_ansi_formals(m4_shiftn(2, $@)))[]dnl
+$1 (b4_c_ansi_formals(m4_shift2($@)))[]dnl
 ])
 
 
@@ -244,9 +267,8 @@ $1 (b4_c_ansi_formals(m4_shiftn(2, $@)))[]dnl
 # --------------------------------------
 # Output the arguments ANSI-C definition.
 m4_define([b4_c_ansi_formals],
-[m4_case([$@],
-        [],   [void],
-        [[]], [void],
+[m4_if([$#], [0], [void],
+       [$#$1], [1], [void],
               [m4_map_sep([b4_c_ansi_formal], [, ], [$@])])])
 
 m4_define([b4_c_ansi_formal],
@@ -298,7 +320,7 @@ $2 $1 ();
 # ----------------------------------------------------------------
 # Declare the function NAME.
 m4_define([b4_c_ansi_function_decl],
-[$2 $1 (b4_c_ansi_formals(m4_shiftn(2, $@)));[]dnl
+[$2 $1 (b4_c_ansi_formals(m4_shift2($@)));[]dnl
 ])
 
 
@@ -313,7 +335,7 @@ m4_define([b4_c_ansi_function_decl],
 # -----------------------------------------------------------
 # Call the function NAME with arguments NAME1, NAME2 etc.
 m4_define([b4_c_function_call],
-[$1 (b4_c_args(m4_shiftn(2, $@)))[]dnl
+[$1 (b4_c_args(m4_shift2($@)))[]dnl
 ])
 
 
@@ -353,7 +375,7 @@ $2
 # -------------------------------------------------
 m4_define([b4_symbol_actions],
 [m4_pushdef([b4_dollar_dollar],
-   [m4_ifval([$6], [(yyvaluep->$6)], [(*yyvaluep)])])dnl
+   [b4_symbol_value([(*yyvaluep)], [$6])])dnl
 m4_pushdef([b4_at_dollar], [(*yylocationp)])dnl
       case $4: /* $3 */
 b4_syncline([$2], [$1])