@table @code
@c Keep this table alphabetized by attribute name. Treat _ as space.
-@item access
@itemx access (@var{access-mode}, @var{ref-index})
@itemx access (@var{access-mode}, @var{ref-index}, @var{size-index})
The access mode @code{none} specifies that the pointer to which it applies
is not used to access the referenced object at all. Unless the pointer is
null the pointed-to object must exist and have at least the size as denoted
-by the @var{size-index} argument. The object need not be initialized.
+by the @var{size-index} argument. When the optional @var{size-index}
+argument is omitted for an argument of @code{void*} type the actual pointer
+agument is ignored. The referenced object need not be initialized.
The mode is intended to be used as a means to help validate the expected
object size, for example in functions that call @code{__builtin_object_size}.
@xref{Object Size Checking}.
if (access.second.minsize
&& access.second.minsize != HOST_WIDE_INT_M1U)
access_nelts = build_int_cstu (sizetype, access.second.minsize);
+ else if (VOID_TYPE_P (argtype) && access.second.mode == access_none)
+ /* Treat access mode none on a void* argument as expecting
+ as little as zero bytes. */
+ access_nelts = size_zero_node;
else
access_nelts = size_one_node;
}
--- /dev/null
+/* PR middle-end/101751 - attribute access none with void pointer expects
+ nonzero size
+ { dg-do compile }
+ { dg-options "-Wall" } */
+
+__attribute__ ((access (none, 1))) void
+fvp_m1 (const void*);
+
+void nowarn_m1 (void)
+{
+ /* Verify these don't trigger a warning for calls to a function
+ declared with attribute access none. */
+ fvp_m1 ((void*)-1); // { dg-bogus "-Wstringop-" }
+ fvp_m1 ((void*)1); // { dg-bogus "-Wstringop-" }
+}
+
+
+__attribute__ ((access (none, 1))) void
+fvp_none (void*);
+
+void nowarn_c_cp1 (void)
+{
+ char c;
+ fvp_none (&c);
+ fvp_none (&c + 1); // { dg-bogus "-Wstringop-" }
+}
+
+void nowarn_f_fp1 (void)
+{
+ fvp_none ((char*)&nowarn_f_fp1);
+ fvp_none ((char*)&nowarn_f_fp1 + 1);
+}
+
+void nowarn_sp1_sp_4 (void)
+{
+ fvp_none ("" + 1); // { dg-bogus "-Wstringop-" }
+ fvp_none ("123" + 4); // { dg-bogus "-Wstringop-" }
+}
+
+
+__attribute__ ((access (none, 1))) void
+wfvp_none (void*); // { dg-message "in a call to function 'wfvp_none' declared with attribute 'access \\\(none, 1\\\)'" }
+
+void warn_cm1_p1 (void)
+{
+ char c;
+ /* With optimization both of the following are diagnosed by -Warray-bounds.
+ The second also without optimization by -Wstringop-overread. They
+ should both be diagnosed by the same warning even without optimization. */
+ wfvp_none (&c - 1); // { dg-warning "" "pr??????" { xfail *-*-* } }
+ wfvp_none (&c + 2); // { dg-warning "" }
+}
+
+void warn_fp2 (void)
+{
+ void *p = (char*)&warn_fp2 + sizeof warn_fp2;
+ fvp_none (p); // { dg-warning "" "pr??????" { xfail *-*-* } }
+}
+
+void warn_sp2 (void)
+{
+ wfvp_none ("" + 2); // { dg-warning "" }
+}