re PR c/3325 (cast of bit-field to same type gets discarded)

	PR c/3325
	* c-decl.c (enum_decl_context): Remove BITFIELD.
	(grokdeclarator): Take bitfield width as an input.
	Ensure bitfields are given the correct type.  Perform
	bitfield width validation with build_bitfield_integer_type
	rather than waiting for finish_struct.
	(grok_typename, grok_typename_in_parm_context, start_decl,
	push_parmdecl, grokfield, start_function): Update calls to
	grokdeclarator.
	(build_bitfield_integer_type): New function.
	(finish_struct): Move bitfield validation to grokdeclarator
	and build_bitfield_integer_type.
	* tree.c (build_nonstandard_integer_type): New function.
	* tree.h (build_nonstandard_integer_type): New prototype.
objc:
	* objc-act.c (objc_copy_list): Remove DECL_INITIAL kludge.
testsuite:
	* gcc.c-torture/compile/20000224-1.c: Update.
	* gcc.c-torture/execute/bitfld-1.c: New tests.
	* gcc.dg/bitfld-1.c, bitfld-2.c: Diagnostic tests.
	* gcc.dg/uninit-A.c: Update.

From-SVN: r49321

gcc/ChangeLog

+2002-01-29  Neil Booth  <neil@daikokuya.demon.co.uk>
+
+	PR c/3325, c/3326, c/2511, c/3347
+	* c-decl.c (enum_decl_context): Remove BITFIELD.
+	(grokdeclarator): Take bitfield width as an input.
+	Ensure bitfields are given the correct type.  Perform
+	bitfield width validation with build_bitfield_integer_type
+	rather than waiting for finish_struct.
+	(grok_typename, grok_typename_in_parm_context, start_decl,
+	push_parmdecl, grokfield, start_function): Update calls to
+	grokdeclarator.
+	(build_bitfield_integer_type): New function.
+	(finish_struct): Move bitfield validation to grokdeclarator
+	and build_bitfield_integer_type. 
+	* tree.c (build_nonstandard_integer_type): New function.
+	* tree.h (build_nonstandard_integer_type): New prototype.
+objc:
+	* objc-act.c (objc_copy_list): Remove DECL_INITIAL kludge.
+
 2002-01-29  Jakub Jelinek  <jakub@redhat.com>
 
 	PR other/1502:

gcc/objc/objc-act.c

@@ -2393,13 +2393,6 @@ objc_copy_list (list, head)
   while (list)
     {
       tail = copy_node (list);
-
-      /* The following statement fixes a bug when inheriting instance
-	 variables that are declared to be bitfields. finish_struct
-	 expects to find the width of the bitfield in DECL_INITIAL.  */
-      if (DECL_BIT_FIELD (tail) && DECL_INITIAL (tail) == 0)
-	DECL_INITIAL (tail) = DECL_SIZE (tail);
-
       newlist = chainon (newlist, tail);
       list = TREE_CHAIN (list);
     }

gcc/testsuite/gcc.c-torture/compile/20000224-1.c

@@ -15,7 +15,7 @@ union Lisp_Object
       {
         enum Lisp_Type type: 3L ;
         unsigned long  markbit: 1;
-        unsigned long  val: 60;
+        unsigned long  val: 32;
       } gu;
     long  i;
   }

gcc/testsuite/gcc.c-torture/execute/bitfld-1.c

+/* Copyright 2002 Free Software Foundation, Inc.
+
+   Tests correct signedness of operations on bitfields; in particular
+   that integer promotions are done correctly, including the case when
+   casts are present.
+
+   The C front end was eliding the cast of an unsigned bitfield to
+   unsigned as a no-op, when in fact it forces a conversion to a
+   full-width unsigned int. (At the time of writing, the C++ front end
+   has a different bug; it erroneously promotes the uncast unsigned
+   bitfield to an unsigned int).
+
+   Source: Neil Booth, 25 Jan 2002, based on PR 3325 (and 3326, which
+   is a different manifestation of the same bug).
+*/
+
+extern void abort ();
+
+int
+main(int argc, char *argv[])
+{
+  struct x { signed int i : 7; unsigned int u : 7; } bit;
+
+  unsigned int u;
+  int i;
+  unsigned int unsigned_result = -13U % 61;
+  int signed_result = -13 % 61;
+
+  bit.u = 61, u = 61; 
+  bit.i = -13, i = -13;
+
+  if (i % u != unsigned_result)
+    abort ();
+  if (i % (unsigned int) u != unsigned_result)
+    abort ();
+
+  /* Somewhat counter-intuitively, bit.u is promoted to an int, making
+     the operands and result an int.  */
+  if (i % bit.u != signed_result)
+    abort ();
+
+  if (bit.i % bit.u != signed_result)
+    abort ();
+
+  /* But with a cast to unsigned int, the unsigned int is promoted to
+     itself as a no-op, and the operands and result are unsigned.  */
+  if (i % (unsigned int) bit.u != unsigned_result)
+    abort ();
+
+  if (bit.i % (unsigned int) bit.u != unsigned_result)
+    abort ();
+
+  return 0;
+}

gcc/testsuite/gcc.dg/bitfld-1.c

+/* Copyright (C) 2002 Free Software Foundation, Inc.
+
+   Tests various diagnostics about a bit-field's type and width.
+
+   Source: Neil Booth, 26 Jan 2002.
+*/
+
+/* { dg-options -pedantic } */
+
+enum foo {e1 = 0, e2, e3, e4, e5};
+
+int x;
+typedef unsigned int ui;
+
+struct bf1
+{
+  unsigned int a: 3.5;		/* { dg-error "integer constant" } */
+  unsigned int b: x;		/* { dg-error "integer constant" } */
+  unsigned int c: -1;		/* { dg-error "negative width" } */
+  unsigned int d: 0;		/* { dg-error "zero width" } */
+  unsigned int : 0;		/* { dg-bogus "zero width" } */
+  unsigned int : 5;
+  double e: 1;			/* { dg-error "invalid type" } */
+  float f: 1;			/* { dg-error "invalid type" } */
+  unsigned long g: 5;		/* { dg-warning "GCC extension" } */
+  ui h: 5;
+  enum foo i: 2;		/* { dg-error "narrower" } */
+  enum foo j: 3;
+  unsigned int k: 256;		/* { dg-error "exceeds its type" } */
+};

gcc/testsuite/gcc.dg/bitfld-2.c

+/* Copyright (C) 2002 Free Software Foundation, Inc.
+
+   Tests we warn about overly-large assignments to bitfields.
+
+   Source: Neil Booth, 28 Jan 2002.
+*/
+
+struct bf
+{
+  unsigned int a: 2;
+  int b: 2;
+};
+
+struct bf p = {4, 0};		/* { dg-warning "truncated" } */
+struct bf q = {0, 2};		/* { dg-warning "overflow" } */
+struct bf r = {3, -2};		/* { dg-bogus "(truncated|overflow)" } */
+
+void foo ()
+{
+  p.a = 4, p.b = 0;		/* { dg-warning "truncated" } */
+  q.a = 0, q.b = 2;		/* { dg-warning "overflow" } */
+  r.a = 3, r.b = -2;		/* { dg-bogus "(truncated|overflow)" } */
+}

gcc/testsuite/gcc.dg/uninit-A.c

@@ -8,7 +8,9 @@ struct tree
 {
     struct tree *car, *cdr, *wfl;
     int code;
-    struct { int renp:1; int rtnp:1; int rpnp:1; } flags;
+    struct { unsigned int renp:1;
+      unsigned int rtnp:1;
+      unsigned int rpnp:1; } flags;
 };
 typedef struct tree *tree;
 #define NULL_TREE ((tree)0)

gcc/tree.c

@@ -3758,6 +3758,29 @@ build_index_type (maxval)
     return itype;
 }
 
+/* Builds a signed or unsigned integer type of precision PRECISION.
+   Used for C bitfields whose precision does not match that of
+   built-in target types.  */
+tree
+build_nonstandard_integer_type (precision, unsignedp)
+     unsigned HOST_WIDE_INT precision;
+     int unsignedp;
+{
+  tree itype = make_node (INTEGER_TYPE);
+
+  TYPE_PRECISION (itype) = precision;
+
+  if (unsignedp)
+    fixup_unsigned_type (itype);
+  else
+    fixup_signed_type (itype);
+
+  if (host_integerp (TYPE_MAX_VALUE (itype), 1))
+    return type_hash_canon (tree_low_cst (TYPE_MAX_VALUE (itype), 1), itype);
+
+  return itype;
+}
+
 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
    ENUMERAL_TYPE, BOOLEAN_TYPE, or CHAR_TYPE), with
    low bound LOWVAL and high bound HIGHVAL.

gcc/tree.h

@@ -2860,6 +2860,7 @@ extern tree getdecls				PARAMS ((void));
 /* Function to return the chain of structure tags in the current scope level.  */
 extern tree gettags				PARAMS ((void));
 
+extern tree build_nonstandard_integer_type	PARAMS ((unsigned int, int));
 extern tree build_range_type PARAMS ((tree, tree, tree));
 
 /* In alias.c */