}
}
+/* Print a warning about casts that might indicate violation
+ of strict aliasing rules if -Wstrict-aliasing is used and
+ strict aliasing mode is in effect. otype is the original
+ TREE_TYPE of expr, and type the type we're casting to. */
+
+void
+strict_aliasing_warning(tree otype, tree type, tree expr)
+{
+ if (flag_strict_aliasing && warn_strict_aliasing
+ && POINTER_TYPE_P (type) && POINTER_TYPE_P (otype)
+ && TREE_CODE (expr) == ADDR_EXPR
+ && (DECL_P (TREE_OPERAND (expr, 0))
+ || handled_component_p (TREE_OPERAND (expr, 0)))
+ && !VOID_TYPE_P (TREE_TYPE (type)))
+ {
+ /* Casting the address of an object to non void pointer. Warn
+ if the cast breaks type based aliasing. */
+ if (!COMPLETE_TYPE_P (TREE_TYPE (type)))
+ warning (OPT_Wstrict_aliasing, "type-punning to incomplete type "
+ "might break strict-aliasing rules");
+ else
+ {
+ HOST_WIDE_INT set1 = get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0)));
+ HOST_WIDE_INT set2 = get_alias_set (TREE_TYPE (type));
+
+ if (!alias_sets_conflict_p (set1, set2))
+ warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
+ "pointer will break strict-aliasing rules");
+ else if (warn_strict_aliasing > 1
+ && !alias_sets_might_conflict_p (set1, set2))
+ warning (OPT_Wstrict_aliasing, "dereferencing type-punned "
+ "pointer might break strict-aliasing rules");
+ }
+ }
+}
+
/* Nonzero if constant C has a value that is permissible
for type TYPE (an INTEGER_TYPE). */
struct Foo {
struct Foo const *ptr; // creates a variant w/o packed flag
- } __ attribute__((packed)); // packs it now.
- */
+ } __ attribute__((packed)); // packs it now.
+ */
tree probe;
for (probe = *node; probe; probe = TYPE_NEXT_VARIANT (probe))
TYPE_PACKED (probe) = 1;
}
-
}
else if (TREE_CODE (*node) == FIELD_DECL)
- DECL_PACKED (*node) = 1;
+ {
+ if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT)
+ warning (OPT_Wattributes,
+ "%qE attribute ignored for field of type %qT",
+ name, TREE_TYPE (*node));
+ else
+ DECL_PACKED (*node) = 1;
+ }
/* We can't set DECL_PACKED for a VAR_DECL, because the bit is
used for DECL_REGISTER. It wouldn't mean anything anyway.
We can't set DECL_PACKED on the type of a TYPE_DECL, because
*no_add_attrs = true;
return NULL_TREE;
}
- cleanup_decl = lang_hooks.decls.lookup_name (cleanup_id);
+ cleanup_decl = lookup_name (cleanup_id);
if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL)
{
error ("cleanup argument not a function");
return false;
}
+/* Subscripting with type char is likely to lose on a machine where
+ chars are signed. So warn on any machine, but optionally. Don't
+ warn for unsigned char since that type is safe. Don't warn for
+ signed char because anyone who uses that must have done so
+ deliberately. Furthermore, we reduce the false positive load by
+ warning only for non-constant value of type char. */
+
+void
+warn_array_subscript_with_type_char (tree index)
+{
+ if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node
+ && TREE_CODE (index) != INTEGER_CST)
+ warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
+}
+
+
#include "gt-c-common.h"