re PR c/2511 (-pedantic not warning about bitfield overflow)

2004-07-08  Joseph S. Myers  <jsm@polyomino.org.uk>
            Neil Booth  <neil@daikokuya.co.uk>

	PR c/2511
	PR c/3325
	* c-decl.c (finish_struct): Ensure bit-fields are given the
	correct type.
	* c-common.c (c_common_signed_or_unsigned_type): For C, require
	the precision to match as well as the mode.
	* expr.c (reduce_to_bit_field_precision): New function.
	(expand_expr_real_1): Reduce expressions of bit-field type to
	proper precision.
	* langhooks.h (reduce_bit_field_operations): New hook.
	* langhooks-def.h (LANG_HOOKS_REDUCE_BIT_FIELD_OPERATIONS):
	Define.
	* c-lang.c, objc/objc-lang.c
	(LANG_HOOKS_REDUCE_BIT_FIELD_OPERATIONS): Define.
	* objc/objc-act.c (check_ivars): Convert types to bit-field types
	before checking.
	* tree.c (build_nonstandard_integer_type): New function.
	* tree.h (build_nonstandard_integer_type): New prototype.
	* tree-ssa.c (tree_ssa_useless_type_conversion_1): Don't treat
	conversions between integer and boolean types as useless.

testsuite:
	* gcc.c-torture/execute/bitfld-1.x: Remove.
	* gcc.c-torture/execute/bitfld-3.c: New test.
	* gcc.dg/bitfld-2.c: Remove XFAILs.

Co-Authored-By: Neil Booth <neil@daikokuya.co.uk>

From-SVN: r84279

1 files changed, 22 insertions, 0 deletions

diff --git a/gcc/tree.c b/gcc/tree.c
index 009888a..3804d37 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -4133,6 +4133,28 @@ build_index_type (tree 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 (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.