c-typeck.c (check_init_type_bitfields): Use nonincremental initialization of…

c-typeck.c (check_init_type_bitfields): Use nonincremental initialization of unions whose first member is a bitfield.

Mon Feb  9 18:57:45 1999  Vladimir N. Makarov  <vmakarov@cygnus.com>
	* c-typeck.c (check_init_type_bitfields): Use nonincremental
	initialization of unions whose first member is a bitfield.
        Remove unnecessary code for checking the declaration mode
        after DECL_C_BIT_FIELD.
	* varasm.c (output_constructor): Additional comment about the
 	constructor of bitfield union initialization.

From-SVN: r25093

gcc/ChangeLog

+Mon Feb  9 18:57:45 1999  Vladimir N. Makarov  <vmakarov@cygnus.com>
+
+	* c-typeck.c (check_init_type_bitfields): Use nonincremental
+	initialization of unions whose first member is a bitfield.
+        Remove unnecessary code for checking the declaration mode
+        after DECL_C_BIT_FIELD.
+
+	* varasm.c (output_constructor): Additional comment about the
+ 	constructor of bitfield union initialization.
+
 Tue Feb  9 11:55:04 1999  Michael Hayes  <m.hayes@elec.canterbury.ac.nz>
 
 	* config/c4x/c4x.md (*movhi_stik): New pattern.

gcc/c-typeck.c

@@ -5480,9 +5480,7 @@ check_init_type_bitfields (type)
       for (tail = TYPE_FIELDS (type); tail;
 	   tail = TREE_CHAIN (tail))
 	{
-	  if (DECL_C_BIT_FIELD (tail)
-	      /* This catches cases like `int foo : 8;'.  */
-	      || DECL_MODE (tail) != TYPE_MODE (TREE_TYPE (tail)))
+	  if (DECL_C_BIT_FIELD (tail))
 	    {
 	      constructor_incremental = 0;
 	      break;
@@ -5492,6 +5490,17 @@ check_init_type_bitfields (type)
 	}
     }
 
+  else if (TREE_CODE (type) == UNION_TYPE)
+    {
+      tree tail = TYPE_FIELDS (type);
+      if (tail && DECL_C_BIT_FIELD (tail))
+	/* We also use the nonincremental algorithm for initiliazation
+	   of unions whose first member is a bitfield, becuase the
+	   incremental algorithm has no code for dealing with
+	   bitfields. */
+	constructor_incremental = 0;
+    }
+
   else if (TREE_CODE (type) == ARRAY_TYPE)
     check_init_type_bitfields (TREE_TYPE (type));
 }

gcc/varasm.c

@@ -3998,7 +3998,11 @@ output_constructor (exp, size)
      FIELD goes through the structure fields, if the constant is a structure.
      if the constant is a union, then we override this,
      by getting the field from the TREE_LIST element.
-     But the constant could also be an array.  Then FIELD is zero.  */
+     But the constant could also be an array.  Then FIELD is zero.
+
+     There is always a maximum of one element in the chain LINK for unions
+     (even if the initializer in a source program incorrectly contains
+     more one). */
   for (link = CONSTRUCTOR_ELTS (exp);
        link;
        link = TREE_CHAIN (link),