X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/68fff38a09c92653f386aab7853b07da9e2f1ebc..ea9e670d728ac659e139434de31ea9306ecdd117:/data/c.m4?ds=sidebyside

diff --git a/data/c.m4 b/data/c.m4
index fee006a3..6c2f5525 100644
--- a/data/c.m4
+++ b/data/c.m4
@@ -17,15 +17,62 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+m4_include(b4_pkgdatadir/[c-like.m4])
+
+# b4_tocpp(STRING)
+# ----------------
+# Convert STRING into a valid C macro name.
+m4_define([b4_tocpp],
+[m4_toupper(m4_bpatsubst(m4_quote($1), [[^a-zA-Z0-9]+], [_]))])
+
+
+# b4_cpp_guard(FILE)
+# ------------------
+# A valid C macro name to use as a CPP header guard for FILE.
+m4_define([b4_cpp_guard],
+[[YY_]b4_tocpp(m4_defn([b4_prefix])/[$1])[_INCLUDED]])
+
+
+# b4_cpp_guard_open(FILE)
+# b4_cpp_guard_close(FILE)
+# ------------------------
+# If FILE does not expand to nothing, open/close CPP inclusion guards for FILE.
+m4_define([b4_cpp_guard_open],
+[m4_ifval(m4_quote($1),
+[#ifndef b4_cpp_guard([$1])
+# define b4_cpp_guard([$1])])])
+
+m4_define([b4_cpp_guard_close],
+[m4_ifval(m4_quote($1),
+[#endif b4_comment([!b4_cpp_guard([$1])])])])
+
+
 ## ---------------- ##
 ## Identification.  ##
 ## ---------------- ##
 
-# b4_comment(TEXT)
-# ----------------
-m4_define([b4_comment], [/* m4_bpatsubst([$1], [
-], [
-   ])  */])
+# b4_comment_(TEXT, OPEN, CONTINUE, END)
+# --------------------------------------
+# Put TEXT in comment.  Avoid trailing spaces: don't indent empty lines.
+# Avoid adding indentation to the first line, as the indentation comes
+# from OPEN.  That's why we don't patsubst([$1], [^\(.\)], [   \1]).
+#
+# Prefix all the output lines with PREFIX.
+m4_define([b4_comment_], [$2[]m4_bpatsubst([$1], [
+\(.\)], [
+$3\1])$4])
+
+
+# b4_comment(TEXT, [PREFIX])
+# --------------------------
+# Put TEXT in comment.  Avoid trailing spaces: don't indent empty lines.
+# Avoid adding indentation to the first line, as the indentation comes
+# from "/*".  That's why we don't patsubst([$1], [^\(.\)], [   \1]).
+#
+# Prefix all the output lines with PREFIX.
+m4_define([b4_comment],
+[b4_comment_([$1], [$2/* ], [$2   ], [$2  */])])
+
 
 # b4_identification
 # -----------------
@@ -50,9 +97,6 @@ m4_define([b4_identification],
 
 /* Pull parsers.  */
 #define YYPULL ]b4_pull_flag])[
-
-/* Using locations.  */
-#define YYLSP_NEEDED ]b4_locations_flag[
 ]])
 
 
@@ -60,11 +104,24 @@ m4_define([b4_identification],
 ## Default values.  ##
 ## ---------------- ##
 
+# b4_api_prefix, b4_api_PREFIX
+# ----------------------------
+# Corresponds to %define api.prefix
+b4_percent_define_default([[api.prefix]], [[yy]])
+m4_define([b4_api_prefix],
+[b4_percent_define_get([[api.prefix]])])
+m4_define([b4_api_PREFIX],
+[m4_toupper(b4_api_prefix)])
+
+
+# b4_prefix
+# ---------
+# If the %name-prefix is not given, it is api.prefix.
+m4_define_default([b4_prefix], [b4_api_prefix])
+
 # If the %union is not named, its name is YYSTYPE.
-m4_define_default([b4_union_name], [YYSTYPE])
+m4_define_default([b4_union_name], [b4_api_PREFIX[]STYPE])
 
-# If the %name-prefix is not given, it is yy.
-m4_define_default([b4_prefix], [yy])
 
 ## ------------------------ ##
 ## Pure/impure interfaces.  ##
@@ -73,7 +130,7 @@ m4_define_default([b4_prefix], [yy])
 # b4_user_args
 # ------------
 m4_define([b4_user_args],
-[m4_ifset([b4_parse_param], [, b4_c_args(b4_parse_param)])])
+[m4_ifset([b4_parse_param], [, b4_args(b4_parse_param)])])
 
 
 # b4_parse_param
@@ -97,11 +154,13 @@ m4_popdef([$2])dnl
 m4_popdef([$1])dnl
 ])])
 
-# b4_parse_param_use
-# ------------------
-# `YYUSE' all the parse-params.
+# b4_parse_param_use([VAL], [LOC])
+# --------------------------------
+# `YYUSE' VAL, LOC if locations are enabled, and all the parse-params.
 m4_define([b4_parse_param_use],
-[b4_parse_param_for([Decl], [Formal], [  YYUSE (Formal);
+[m4_ifvaln([$1], [  YYUSE([$1]);])dnl
+b4_locations_if([m4_ifvaln([$2], [  YYUSE ([$2]);])])dnl
+b4_parse_param_for([Decl], [Formal], [  YYUSE (Formal);
 ])dnl
 ])
 
@@ -123,7 +182,7 @@ m4_define([b4_int_type],
 
        m4_eval([0 <= $1]),                [1], [unsigned int],
 
-					       [int])])
+                                               [int])])
 
 
 # b4_int_type_for(NAME)
@@ -138,13 +197,12 @@ m4_define([b4_int_type_for],
 # --------------------------------------------
 # Without inducing a comparison warning from the compiler, check if the
 # literal value LITERAL equals VALUE from table TABLE, which must have
-# TABLE_min and TABLE_max defined.  YYID must be defined as an identity
-# function that suppresses warnings about constant conditions.
+# TABLE_min and TABLE_max defined.
 m4_define([b4_table_value_equals],
 [m4_if(m4_eval($3 < m4_indir([b4_]$1[_min])
                || m4_indir([b4_]$1[_max]) < $3), [1],
-       [[YYID (0)]],
-       [[((]$2[) == (]$3[))]])])
+       [[0]],
+       [(!!(($2) == ($3)))])])
 
 
 ## ---------##
@@ -172,166 +230,125 @@ m4_define([b4_null_define],
 # Return a null pointer constant.
 m4_define([b4_null], [YY_NULL])
 
+# b4_integral_parser_table_define(TABLE-NAME, CONTENT, COMMENT)
+# -------------------------------------------------------------
+# Define "yy<TABLE-NAME>" which contents is CONTENT.
+m4_define([b4_integral_parser_table_define],
+[m4_ifvaln([$3], [b4_comment([$3], [  ])])dnl
+static const b4_int_type_for([$2]) yy$1[[]] =
+{
+  $2
+};dnl
+])
 
 
 ## ------------------------- ##
 ## Assigning token numbers.  ##
 ## ------------------------- ##
 
-# b4_token_define(TOKEN-NAME, TOKEN-NUMBER)
-# -----------------------------------------
+# b4_token_define(TOKEN-NUM)
+# --------------------------
 # Output the definition of this token as #define.
 m4_define([b4_token_define],
-[#define $1 $2
-])
+[b4_token_format([#define %s %s], [$1])])
 
-
-# b4_token_defines(LIST-OF-PAIRS-TOKEN-NAME-TOKEN-NUMBER)
-# -------------------------------------------------------
-# Output the definition of the tokens (if there are) as #defines.
+# b4_token_defines
+# ----------------
+# Output the definition of the tokens.
 m4_define([b4_token_defines],
-[m4_if([$#$1], [1], [],
-[/* Tokens.  */
-m4_map([b4_token_define], [$@])])
-])
+[b4_any_token_visible_if([/* Tokens.  */
+m4_join([
+], b4_symbol_map([b4_token_define]))
+])])
 
 
-# b4_token_enum(TOKEN-NAME, TOKEN-NUMBER)
-# ---------------------------------------
+# b4_token_enum(TOKEN-NUM)
+# ------------------------
 # Output the definition of this token as an enum.
 m4_define([b4_token_enum],
-[$1 = $2])
+[b4_token_format([%s = %s], [$1])])
 
 
-# b4_token_enums(LIST-OF-PAIRS-TOKEN-NAME-TOKEN-NUMBER)
-# -----------------------------------------------------
+# b4_token_enums
+# --------------
 # Output the definition of the tokens (if there are) as enums.
 m4_define([b4_token_enums],
-[m4_if([$#$1], [1], [],
-[/* Tokens.  */
-#ifndef YYTOKENTYPE
-# define YYTOKENTYPE
-   /* Put the tokens into the symbol table, so that GDB and other debuggers
-      know about them.  */
-   enum yytokentype {
-m4_map_sep([     b4_token_enum], [,
-],
-	   [$@])
-   };
+[b4_any_token_visible_if([[/* Tokens.  */
+#ifndef ]b4_api_PREFIX[TOKENTYPE
+# define ]b4_api_PREFIX[TOKENTYPE
+  /* Put the tokens into the symbol table, so that GDB and other debuggers
+     know about them.  */
+  enum ]b4_api_prefix[tokentype
+  {
+    ]m4_join([,
+    ],
+             b4_symbol_map([b4_token_enum]))[
+  };
 #endif
-])])
+]])])
 
 
-# b4_token_enums_defines(LIST-OF-PAIRS-TOKEN-NAME-TOKEN-NUMBER)
-# -------------------------------------------------------------
-# Output the definition of the tokens (if there are any) as enums and, if POSIX
-# Yacc is enabled, as #defines.
+# b4_token_enums_defines
+# ----------------------
+# Output the definition of the tokens (if there are any) as enums and,
+# if POSIX Yacc is enabled, as #defines.
 m4_define([b4_token_enums_defines],
-[b4_token_enums($@)b4_yacc_if([b4_token_defines($@)], [])
-])
+[b4_token_enums[]b4_yacc_if([b4_token_defines])])
 
 
+## ----------------- ##
+## Semantic Values.  ##
+## ----------------- ##
 
-## --------------------------------------------- ##
-## Defining C functions in both K&R and ANSI-C.  ##
-## --------------------------------------------- ##
 
+# 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]))])
 
-# b4_modern_c
-# -----------
-# A predicate useful in #if to determine whether C is ancient or modern.
-#
-# If __STDC__ is defined, the compiler is modern.  IBM xlc 7.0 when run
-# as 'cc' doesn't define __STDC__ (or __STDC_VERSION__) for pedantic
-# reasons, but it defines __C99__FUNC__ so check that as well.
-# Microsoft C normally doesn't define these macros, but it defines _MSC_VER.
-# Consider a C++ compiler to be modern if it defines __cplusplus.
-#
-m4_define([b4_c_modern],
-  [[(defined __STDC__ || defined __C99__FUNC__ \
-     || defined __cplusplus || defined _MSC_VER)]])
 
-# b4_c_function_def(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
-# ----------------------------------------------------------
-# Declare the function NAME.
-m4_define([b4_c_function_def],
-[#if b4_c_modern
-b4_c_ansi_function_def($@)
-#else
-$2
-$1 (b4_c_knr_formal_names(m4_shift2($@)))
-b4_c_knr_formal_decls(m4_shift2($@))
-#endif[]dnl
-])
 
+## ---------------------- ##
+## Defining C functions.  ##
+## ---------------------- ##
 
-# b4_c_ansi_function_def(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
-# ---------------------------------------------------------------
-# Declare the function NAME in ANSI.
-m4_define([b4_c_ansi_function_def],
+
+# b4_function_define(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
+# -----------------------------------------------------------
+# Declare the function NAME in C.
+m4_define([b4_function_define],
 [$2
-$1 (b4_c_ansi_formals(m4_shift2($@)))[]dnl
+$1 (b4_formals(m4_shift2($@)))[]dnl
 ])
 
 
-# b4_c_ansi_formals([DECL1, NAME1], ...)
-# --------------------------------------
-# Output the arguments ANSI-C definition.
-m4_define([b4_c_ansi_formals],
+# b4_formals([DECL1, NAME1], ...)
+# -------------------------------
+# The formal arguments of a C function definition.
+m4_define([b4_formals],
 [m4_if([$#], [0], [void],
        [$#$1], [1], [void],
-	       [m4_map_sep([b4_c_ansi_formal], [, ], [$@])])])
+               [m4_map_sep([b4_formal], [, ], [$@])])])
 
-m4_define([b4_c_ansi_formal],
+m4_define([b4_formal],
 [$1])
 
 
-# b4_c_knr_formal_names([DECL1, NAME1], ...)
-# ------------------------------------------
-# Output the argument names.
-m4_define([b4_c_knr_formal_names],
-[m4_map_sep([b4_c_knr_formal_name], [, ], [$@])])
-
-m4_define([b4_c_knr_formal_name],
-[$2])
-
-
-# b4_c_knr_formal_decls([DECL1, NAME1], ...)
-# ------------------------------------------
-# Output the K&R argument declarations.
-m4_define([b4_c_knr_formal_decls],
-[m4_map_sep([b4_c_knr_formal_decl],
-	    [
-],
-	    [$@])])
-
-m4_define([b4_c_knr_formal_decl],
-[    $1;])
-
 
+## ----------------------- ##
+## Declaring C functions.  ##
+## ----------------------- ##
 
-## ------------------------------------------------------------ ##
-## Declaring (prototyping) C functions in both K&R and ANSI-C.  ##
-## ------------------------------------------------------------ ##
 
-
-# b4_c_function_decl(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
-# -----------------------------------------------------------
+# b4_function_declare(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
+# ------------------------------------------------------------
 # Declare the function NAME.
-m4_define([b4_c_function_decl],
-[#if defined __STDC__ || defined __cplusplus
-b4_c_ansi_function_decl($@)
-#else
-$2 $1 ();
-#endif[]dnl
-])
-
-
-# b4_c_ansi_function_decl(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
-# ----------------------------------------------------------------
-# Declare the function NAME.
-m4_define([b4_c_ansi_function_decl],
-[$2 $1 (b4_c_ansi_formals(m4_shift2($@)));[]dnl
+m4_define([b4_function_declare],
+[$2 $1 (b4_formals(m4_shift2($@)));[]dnl
 ])
 
 
@@ -342,21 +359,21 @@ m4_define([b4_c_ansi_function_decl],
 ## --------------------- ##
 
 
-# b4_c_function_call(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
+# b4_function_call(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
 # -----------------------------------------------------------
 # Call the function NAME with arguments NAME1, NAME2 etc.
-m4_define([b4_c_function_call],
-[$1 (b4_c_args(m4_shift2($@)))[]dnl
+m4_define([b4_function_call],
+[$1 (b4_args(m4_shift2($@)))[]dnl
 ])
 
 
-# b4_c_args([DECL1, NAME1], ...)
-# ------------------------------
+# b4_args([DECL1, NAME1], ...)
+# ----------------------------
 # Output the arguments NAME1, NAME2...
-m4_define([b4_c_args],
-[m4_map_sep([b4_c_arg], [, ], [$@])])
+m4_define([b4_args],
+[m4_map_sep([b4_arg], [, ], [$@])])
 
-m4_define([b4_c_arg],
+m4_define([b4_arg],
 [$2])
 
 
@@ -365,7 +382,7 @@ m4_define([b4_c_arg],
 ## ----------- ##
 
 # b4_sync_start(LINE, FILE)
-# -----------------------
+# -------------------------
 m4_define([b4_sync_start], [[#]line $1 $2])
 
 
@@ -378,38 +395,28 @@ m4_define([b4_sync_start], [[#]line $1 $2])
 m4_define([b4_case],
 [  case $1:
 $2
+b4_syncline([@oline@], [@ofile@])
     break;])
 
-# b4_symbol_actions(FILENAME, LINENO,
-#                   SYMBOL-TAG, SYMBOL-NUM,
-#                   SYMBOL-ACTION, SYMBOL-TYPENAME)
-# -------------------------------------------------
-m4_define([b4_symbol_actions],
-[m4_pushdef([b4_dollar_dollar],
-   [m4_ifval([$6], [(yyvaluep->$6)], [(*yyvaluep)])])dnl
-m4_pushdef([b4_at_dollar], [(*yylocationp)])dnl
-      case $4: /* $3 */
-b4_syncline([$2], [$1])
-	$5;
+
+# b4_predicate_case(LABEL, CONDITIONS)
+# ------------------------------------
+m4_define([b4_predicate_case],
+[  case $1:
+    if (! ($2)) YYERROR;
 b4_syncline([@oline@], [@ofile@])
-	break;
-m4_popdef([b4_at_dollar])dnl
-m4_popdef([b4_dollar_dollar])dnl
-])
+    break;])
 
 
-# b4_yydestruct_generate(FUNCTION-DECLARATOR)
-# -------------------------------------------
-# Generate the "yydestruct" function, which declaration is issued using
-# FUNCTION-DECLARATOR, which may be "b4_c_ansi_function_def" for ISO C
-# or "b4_c_function_def" for K&R.
-m4_define_default([b4_yydestruct_generate],
+# b4_yydestruct_define
+# --------------------
+# Define the "yydestruct" function.
+m4_define_default([b4_yydestruct_define],
 [[/*-----------------------------------------------.
 | Release the memory associated to this symbol.  |
 `-----------------------------------------------*/
 
-/*ARGSUSED*/
-]$1([yydestruct],
+]b4_function_define([yydestruct],
     [static void],
     [[const char *yymsg],    [yymsg]],
     [[int yytype],           [yytype]],
@@ -417,63 +424,54 @@ m4_define_default([b4_yydestruct_generate],
 b4_locations_if(            [, [[YYLTYPE *yylocationp], [yylocationp]]])[]dnl
 m4_ifset([b4_parse_param], [, b4_parse_param]))[
 {
-  YYUSE (yyvaluep);
-]b4_locations_if([  YYUSE (yylocationp);
-])dnl
-b4_parse_param_use[]dnl
-[
-  if (!yymsg)
+]b4_parse_param_use([yyvaluep], [yylocationp])dnl
+[  if (!yymsg)
     yymsg = "Deleting";
   YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);
 
   switch (yytype)
     {
-]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[
-      default:
-	break;
+]b4_symbol_foreach([b4_symbol_destructor])dnl
+[      default:
+        break;
     }
 }]dnl
 ])
 
 
-# b4_yy_symbol_print_generate(FUNCTION-DECLARATOR)
-# ------------------------------------------------
-# Generate the "yy_symbol_print" function, which declaration is issued using
-# FUNCTION-DECLARATOR, which may be "b4_c_ansi_function_def" for ISO C
-# or "b4_c_function_def" for K&R.
-m4_define_default([b4_yy_symbol_print_generate],
+# b4_yy_symbol_print_define
+# -------------------------
+# Define the "yy_symbol_print" function.
+m4_define_default([b4_yy_symbol_print_define],
 [[
 /*--------------------------------.
 | Print this symbol on YYOUTPUT.  |
 `--------------------------------*/
 
-/*ARGSUSED*/
-]$1([yy_symbol_value_print],
+]b4_function_define([yy_symbol_value_print],
     [static void],
-	       [[FILE *yyoutput],                       [yyoutput]],
-	       [[int yytype],                           [yytype]],
-	       [[YYSTYPE const * const yyvaluep],       [yyvaluep]][]dnl
+               [[FILE *yyoutput],                       [yyoutput]],
+               [[int yytype],                           [yytype]],
+               [[YYSTYPE const * const yyvaluep],       [yyvaluep]][]dnl
 b4_locations_if([, [[YYLTYPE const * const yylocationp], [yylocationp]]])[]dnl
 m4_ifset([b4_parse_param], [, b4_parse_param]))[
 {
   FILE *yyo = yyoutput;
-  YYUSE (yyo);
-  if (!yyvaluep)
-    return;
-]b4_locations_if([  YYUSE (yylocationp);
-])dnl
-b4_parse_param_use[]dnl
-[# ifdef YYPRINT
+]b4_parse_param_use([yyo], [yylocationp])dnl
+[  if (!yyvaluep)
+    return;]
+dnl glr.c does not feature yytoknum.
+m4_if(b4_skeleton, ["yacc.c"],
+[[# ifdef YYPRINT
   if (yytype < YYNTOKENS)
     YYPRINT (yyoutput, yytoknum[yytype], *yyvaluep);
-# else
-  YYUSE (yyoutput);
 # endif
-  switch (yytype)
+]])dnl
+[  switch (yytype)
     {
-]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
+]b4_symbol_foreach([b4_symbol_printer])dnl
 [      default:
-	break;
+        break;
     }
 }
 
@@ -482,11 +480,11 @@ b4_parse_param_use[]dnl
 | Print this symbol on YYOUTPUT.  |
 `--------------------------------*/
 
-]$1([yy_symbol_print],
+]b4_function_define([yy_symbol_print],
     [static void],
-	       [[FILE *yyoutput],                       [yyoutput]],
-	       [[int yytype],                           [yytype]],
-	       [[YYSTYPE const * const yyvaluep],       [yyvaluep]][]dnl
+               [[FILE *yyoutput],                       [yyoutput]],
+               [[int yytype],                           [yytype]],
+               [[YYSTYPE const * const yyvaluep],       [yyvaluep]][]dnl
 b4_locations_if([, [[YYLTYPE const * const yylocationp], [yylocationp]]])[]dnl
 m4_ifset([b4_parse_param], [, b4_parse_param]))[
 {
@@ -503,3 +501,169 @@ b4_locations_if([, yylocationp])[]b4_user_args[);
   YYFPRINTF (yyoutput, ")");
 }]dnl
 ])
+
+## -------------- ##
+## Declarations.  ##
+## -------------- ##
+
+# b4_declare_yylstype
+# -------------------
+# Declarations that might either go into the header (if --defines) or
+# in the parser body.  Declare YYSTYPE/YYLTYPE, and yylval/yylloc.
+m4_define([b4_declare_yylstype],
+[[#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
+]m4_ifdef([b4_stype],
+[[typedef union ]b4_union_name[
+{
+]b4_user_stype[
+} ]b4_api_PREFIX[STYPE;
+# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1]],
+[m4_if(b4_tag_seen_flag, 0,
+[[typedef int ]b4_api_PREFIX[STYPE;
+# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1]])])[
+# define ]b4_api_PREFIX[STYPE_IS_DECLARED 1
+#endif]b4_locations_if([[
+
+#if ! defined ]b4_api_PREFIX[LTYPE && ! defined ]b4_api_PREFIX[LTYPE_IS_DECLARED
+typedef struct ]b4_api_PREFIX[LTYPE
+{
+  int first_line;
+  int first_column;
+  int last_line;
+  int last_column;
+} ]b4_api_PREFIX[LTYPE;
+# define ]b4_api_PREFIX[LTYPE_IS_DECLARED 1
+# define ]b4_api_PREFIX[LTYPE_IS_TRIVIAL 1
+#endif]])
+
+b4_pure_if([], [[extern ]b4_api_PREFIX[STYPE ]b4_prefix[lval;
+]b4_locations_if([[extern ]b4_api_PREFIX[LTYPE ]b4_prefix[lloc;]])])[]dnl
+])
+
+# b4_YYDEBUG_define
+# ------------------
+m4_define([b4_YYDEBUG_define],
+[[/* Enabling traces.  */
+]m4_if(b4_api_prefix, [yy],
+[[#ifndef YYDEBUG
+# define YYDEBUG ]b4_parse_trace_if([1], [0])[
+#endif]],
+[[#ifndef ]b4_api_PREFIX[DEBUG
+# if defined YYDEBUG
+#if YYDEBUG
+#   define ]b4_api_PREFIX[DEBUG 1
+#  else
+#   define ]b4_api_PREFIX[DEBUG 0
+#  endif
+# else /* ! defined YYDEBUG */
+#  define ]b4_api_PREFIX[DEBUG ]b4_parse_trace_if([1], [0])[
+# endif /* ! defined YYDEBUG */
+#endif  /* ! defined ]b4_api_PREFIX[DEBUG */]])[]dnl
+])
+
+# b4_declare_yydebug
+# ------------------
+m4_define([b4_declare_yydebug],
+[b4_YYDEBUG_define[
+#if ]b4_api_PREFIX[DEBUG
+extern int ]b4_prefix[debug;
+#endif][]dnl
+])
+
+# 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).first_line   = YYRHSLOC (Rhs, 1).first_line;        \
+          (Current).first_column = YYRHSLOC (Rhs, 1).first_column;      \
+          (Current).last_line    = YYRHSLOC (Rhs, N).last_line;         \
+          (Current).last_column  = YYRHSLOC (Rhs, N).last_column;       \
+        }                                                               \
+      else                                                              \
+        {                                                               \
+          (Current).first_line   = (Current).last_line   =              \
+            YYRHSLOC (Rhs, 0).last_line;                                \
+          (Current).first_column = (Current).last_column =              \
+            YYRHSLOC (Rhs, 0).last_column;                              \
+        }                                                               \
+    while (0)
+#endif
+]])
+
+# b4_yy_location_print_define
+# ---------------------------
+# Define YY_LOCATION_PRINT.
+m4_define([b4_yy_location_print_define],
+[b4_locations_if([[
+/* YY_LOCATION_PRINT -- Print the location on the stream.
+   This macro was not mandated originally: define only if we know
+   we won't break user code: when these are the locations we know.  */
+
+#ifndef YY_LOCATION_PRINT
+# if defined ]b4_api_PREFIX[LTYPE_IS_TRIVIAL && ]b4_api_PREFIX[LTYPE_IS_TRIVIAL
+
+/* Print *YYLOCP on YYO.  Private, do not rely on its existence. */
+
+__attribute__((__unused__))
+]b4_function_define([yy_location_print_],
+    [static unsigned],
+               [[FILE *yyo],                    [yyo]],
+               [[YYLTYPE const * const yylocp], [yylocp]])[
+{
+  unsigned res = 0;
+  int end_col = 0 != yylocp->last_column ? yylocp->last_column - 1 : 0;
+  if (0 <= yylocp->first_line)
+    {
+      res += fprintf (yyo, "%d", yylocp->first_line);
+      if (0 <= yylocp->first_column)
+        res += fprintf (yyo, ".%d", yylocp->first_column);
+    }
+  if (0 <= yylocp->last_line)
+    {
+      if (yylocp->first_line < yylocp->last_line)
+        {
+          res += fprintf (yyo, "-%d", yylocp->last_line);
+          if (0 <= end_col)
+            res += fprintf (yyo, ".%d", end_col);
+        }
+      else if (0 <= end_col && yylocp->first_column < end_col)
+        res += fprintf (yyo, "-%d", end_col);
+    }
+  return res;
+ }
+
+#  define YY_LOCATION_PRINT(File, Loc)                                   \
+  yy_location_print_ (File, &(Loc))
+
+# else
+#  define YY_LOCATION_PRINT(File, Loc) ((void) 0)
+# endif
+#endif]],
+[[/* This macro is provided for backward compatibility. */
+#ifndef YY_LOCATION_PRINT
+# define YY_LOCATION_PRINT(File, Loc) ((void) 0)
+#endif]])
+])
+
+# b4_yyloc_default
+# ----------------
+# Expand to a possible default value for yylloc.
+m4_define([b4_yyloc_default],
+[[
+# if defined ]b4_api_PREFIX[LTYPE_IS_TRIVIAL && ]b4_api_PREFIX[LTYPE_IS_TRIVIAL
+  = { ]m4_join([, ],
+               m4_defn([b4_location_initial_line]),
+               m4_defn([b4_location_initial_column]),
+               m4_defn([b4_location_initial_line]),
+               m4_defn([b4_location_initial_column]))[ }
+# endif
+]])