1 files changed, 101 insertions, 0 deletions
diff --git a/clang/test/Sema/attr-counted-by-void-ptr-gnu.c b/clang/test/Sema/attr-counted-by-void-ptr-gnu.c
new file mode 100644
index 0000000..c1ed5f8
--- /dev/null
+++ b/clang/test/Sema/attr-counted-by-void-ptr-gnu.c
@@ -0,0 +1,101 @@
+// RUN: %clang_cc1 -fsyntax-only -verify=expected-nowarn %s
+// RUN: %clang_cc1 -Wpointer-arith -fsyntax-only -verify=expected-warn %s
+// RUN: %clang_cc1 -fexperimental-bounds-safety -fsyntax-only -verify=expected-bounds %s
+
+// expected-nowarn-no-diagnostics
+// expected-bounds-no-diagnostics
+
+#define NULL (void*)0
+#define __counted_by(f)  __attribute__((counted_by(f)))
+#define __counted_by_or_null(f)  __attribute__((counted_by_or_null(f)))
+#define __sized_by(f)  __attribute__((sized_by(f)))
+
+//==============================================================================
+// Test: counted_by on void* is allowed (warns with -Wpointer-arith)
+//==============================================================================
+
+struct test_void_ptr_gnu {
+  int count;
+  // expected-warn-warning@+2{{'counted_by' on a pointer to void is a GNU extension, treated as 'sized_by'}}
+  // expected-warn-note@+1{{use '__sized_by' to suppress this warning}}
+  void* buf __counted_by(count);
+};
+
+struct test_const_void_ptr_gnu {
+  int count;
+  // expected-warn-warning@+2{{'counted_by' on a pointer to void is a GNU extension, treated as 'sized_by'}}
+  // expected-warn-note@+1{{use '__sized_by' to suppress this warning}}
+  const void* buf __counted_by(count);
+};
+
+struct test_volatile_void_ptr_gnu {
+  int count;
+  // expected-warn-warning@+2{{'counted_by' on a pointer to void is a GNU extension, treated as 'sized_by'}}
+  // expected-warn-note@+1{{use '__sized_by' to suppress this warning}}
+  volatile void* buf __counted_by(count);
+};
+
+struct test_const_volatile_void_ptr_gnu {
+  int count;
+  // expected-warn-warning@+2{{'counted_by' on a pointer to void is a GNU extension, treated as 'sized_by'}}
+  // expected-warn-note@+1{{use '__sized_by' to suppress this warning}}
+  const volatile void* buf __counted_by(count);
+};
+
+// Verify sized_by still works the same way (always allowed, no warning)
+struct test_sized_by_void_ptr {
+  int size;
+  void* buf __sized_by(size);  // OK in both modes, no warning
+};
+
+//==============================================================================
+// Test: counted_by_or_null on void* behaves the same
+//==============================================================================
+
+struct test_void_ptr_or_null_gnu {
+  int count;
+  // expected-warn-warning@+2{{'counted_by_or_null' on a pointer to void is a GNU extension, treated as 'sized_by_or_null'}}
+  // expected-warn-note@+1{{use '__sized_by_or_null' to suppress this warning}}
+  void* buf __counted_by_or_null(count);
+};
+
+struct test_const_void_ptr_or_null_gnu {
+  int count;
+  // expected-warn-warning@+2{{'counted_by_or_null' on a pointer to void is a GNU extension, treated as 'sized_by_or_null'}}
+  // expected-warn-note@+1{{use '__sized_by_or_null' to suppress this warning}}
+  const void* buf __counted_by_or_null(count);
+};
+
+//==============================================================================
+// Test: Using void* __counted_by(...) pointers (not just declaring them)
+//==============================================================================
+
+// Verify that void* __counted_by pointers can be used as rvalues, assigned to,
+// passed to functions, etc.
+
+void* use_as_rvalue(struct test_void_ptr_gnu* t) {
+  return t->buf;
+}
+
+void assign_to_pointer(struct test_void_ptr_gnu* t) {
+  t->buf = NULL;
+  t->count = 0;
+}
+
+extern void* my_allocator(unsigned long);
+
+void assign_from_allocator(struct test_void_ptr_gnu* t) {
+  t->buf = my_allocator(100);
+  t->count = 100;
+}
+
+void takes_void_ptr(void* p);
+
+void pass_to_function(struct test_void_ptr_gnu* t) {
+  takes_void_ptr(t->buf);
+}
+
+void* pointer_arithmetic(struct test_void_ptr_gnu* t) {
+  // expected-warn-warning@+1{{arithmetic on a pointer to void is a GNU extension}}
+  return t->buf + 10;
+}