skeletons: avoid empty switch constructs

[bison.git] / data / c.m4

diff --git a/data/c.m4 b/data/c.m4
index c2f1a053fb9897c281bc2c285b1615b0ccdbffb1..bcafe422600e477fe456dde7761e22a0970596fa 100644 (file)
--- a/data/c.m4
+++ b/data/c.m4
@@ -187,9 +187,29 @@ m4_define([b4_table_value_equals],
        [(!!(($2) == ($3)))])])
 
 
-## ---------##
-## Values.  ##
-## ---------##
+## ----------------- ##
+## Compiler issues.  ##
+## ----------------- ##
+
+# b4_attribute_define
+# -------------------
+# Provide portability for __attribute__.
+m4_define([b4_attribute_define],
+[#ifndef __attribute__
+/* This feature is available in gcc versions 2.5 and later.  */
+# if (! defined __GNUC__ || __GNUC__ < 2 \
+      || (__GNUC__ == 2 && __GNUC_MINOR__ < 5))
+#  define __attribute__(Spec) /* empty */
+# endif
+#endif
+
+/* Suppress unused-variable warnings by "using" E.  */
+#if ! defined lint || defined __GNUC__
+# define YYUSE(E) ((void) (E))
+#else
+# define YYUSE(E) /* empty */
+#endif
+])
 
 
 # b4_null_define
@@ -405,7 +425,7 @@ m4_define([b4_c_arg],
 ## ----------- ##
 
 # b4_sync_start(LINE, FILE)
-# -----------------------
+# -------------------------
 m4_define([b4_sync_start], [[#]line $1 $2])
 
 
@@ -420,15 +440,15 @@ m4_define([b4_case],
 $2
     break;])
 
-# b4_symbol_actions(FILENAME, LINENO,
-#                   SYMBOL-TAG, SYMBOL-NUM,
-#                   SYMBOL-ACTION, SYMBOL-TYPENAME)
-# -------------------------------------------------
+# _b4_symbol_actions(FILENAME, LINENO,
+#                    SYMBOL-TAG, SYMBOL-NUM,
+#                    SYMBOL-ACTION, SYMBOL-TYPENAME)
+# --------------------------------------------------
 # Issue the code for a symbol action (e.g., %printer).
 #
 # Define b4_dollar_dollar([TYPE-NAME]), and b4_at_dollar, which are
 # invoked where $<TYPE-NAME>$ and @$ were specified by the user.
-m4_define([b4_symbol_actions],
+m4_define([_b4_symbol_actions],
 [b4_dollar_pushdef([(*yyvaluep)], [$6], [(*yylocationp)])dnl
       case $4: /* $3 */
 b4_syncline([$2], [$1])
@@ -438,6 +458,20 @@ b4_syncline([@oline@], [@ofile@])
 b4_dollar_popdef[]dnl
 ])
 
+# b4_symbol_actions(KIND)
+# -----------------------
+# Emit the symbol actions for KIND ("printers" or "destructors").
+# Dispatch on "yytype".
+m4_define([b4_symbol_actions],
+[m4_ifval(m4_defn([b4_symbol_$1]),
+[[switch (yytype)
+    {
+]m4_map([_b4_symbol_actions], m4_defn([b4_symbol_$1]))[
+      default:
+        break;
+    }]],
+[YYUSE (yytype);])])
+
 
 # b4_yydestruct_generate(FUNCTION-DECLARATOR)
 # -------------------------------------------
@@ -467,12 +501,7 @@ b4_parse_param_use[]dnl
     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_actions([destructors])[
 }]dnl
 ])
 
@@ -510,12 +539,7 @@ b4_parse_param_use[]dnl
 # else
   YYUSE (yyoutput);
 # endif
-  switch (yytype)
-    {
-]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
-[      default:
-        break;
-    }
+  ]b4_symbol_actions([printers])[
 }
 
 
@@ -655,14 +679,40 @@ m4_define([b4_yy_location_print_define],
 
 #ifndef YY_LOCATION_PRINT
 # if defined ]b4_api_PREFIX[LTYPE_IS_TRIVIAL && ]b4_api_PREFIX[LTYPE_IS_TRIVIAL
-#  define YY_LOCATION_PRINT(File, Loc)                                   \
-  do {                                                                   \
-    fprintf (File, "%d.%d", (Loc).first_line, (Loc).first_column);       \
-    if ((Loc).first_line < (Loc).last_line)                              \
-      fprintf (File, "-%d.%d", (Loc).last_line,  (Loc).last_column - 1); \
-    else if ((Loc).first_column < (Loc).last_column - 1)                 \
-      fprintf (File, "-%d", (Loc).last_column - 1);                      \
-  } while (0)
+
+/* Print *YYLOCP on YYO.  Private, do not rely on its existence. */
+
+__attribute__((__unused__))
+]b4_c_function_def([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