c-family: Fix up -Wsizeof-pointer-memaccess ICEs [PR117230]

In the following testcases, we ICE on all 4 function calls.
The problem is using TYPE_PRECISION on vector types (but guess it
would be similarly problematic on structures/unions/arrays).
The test only differentiates between suggestion what to do, whether
to supply explicit size because sizeof (*p) for
{,{,un}signed }char *p is not very likely what the user want, or
dereferencing the pointer, so I think limiting that suggestion
to integral types is ok.

2024-10-22  Jakub Jelinek  <jakub@redhat.com>

	PR c/117230
	* c-warn.cc (sizeof_pointer_memaccess_warning): Only compare
	TYPE_PRECISION of TREE_TYPE (type) to precision of char if
	TREE_TYPE (type) is integral type.

	* c-c++-common/Wsizeof-pointer-memaccess5.c: New test.

diff --git a/gcc/c-family/c-warn.cc b/gcc/c-family/c-warn.cc
index 47e0a6bfa07373ad53400da7fa80d58ce8ea5600..05d6e37edaee2f1bc9c1857ae878074b0485e47f 100644 (file)
--- a/gcc/c-family/c-warn.cc
+++ b/gcc/c-family/c-warn.cc
@@ -944,8 +944,9 @@ sizeof_pointer_memaccess_warning (location_t *sizeof_arg_loc, tree callee,
                        "argument to %<sizeof%> in %qD call is the same "
                        "expression as the destination; did you mean to "
                        "remove the addressof?", callee);
-         else if ((TYPE_PRECISION (TREE_TYPE (type))
-                   == TYPE_PRECISION (char_type_node))
+         else if ((INTEGRAL_TYPE_P (TREE_TYPE (type))
+                   && (TYPE_PRECISION (TREE_TYPE (type))
+                       == TYPE_PRECISION (char_type_node)))
                   || strop)
            warning_at (loc, OPT_Wsizeof_pointer_memaccess,
                        "argument to %<sizeof%> in %qD call is the same "
@@ -984,8 +985,9 @@ sizeof_pointer_memaccess_warning (location_t *sizeof_arg_loc, tree callee,
                        "argument to %<sizeof%> in %qD call is the same "
                        "expression as the source; did you mean to "
                        "remove the addressof?", callee);
-         else if ((TYPE_PRECISION (TREE_TYPE (type))
-                   == TYPE_PRECISION (char_type_node))
+         else if ((INTEGRAL_TYPE_P (TREE_TYPE (type))
+                   && (TYPE_PRECISION (TREE_TYPE (type))
+                       == TYPE_PRECISION (char_type_node)))
                   || strop)
            warning_at (loc, OPT_Wsizeof_pointer_memaccess,
                        "argument to %<sizeof%> in %qD call is the same "
@@ -1024,8 +1026,9 @@ sizeof_pointer_memaccess_warning (location_t *sizeof_arg_loc, tree callee,
                        "argument to %<sizeof%> in %qD call is the same "
                        "expression as the first source; did you mean to "
                        "remove the addressof?", callee);
-         else if ((TYPE_PRECISION (TREE_TYPE (type))
-                   == TYPE_PRECISION (char_type_node))
+         else if ((INTEGRAL_TYPE_P (TREE_TYPE (type))
+                   && (TYPE_PRECISION (TREE_TYPE (type))
+                       == TYPE_PRECISION (char_type_node)))
                   || strop)
            warning_at (loc, OPT_Wsizeof_pointer_memaccess,
                        "argument to %<sizeof%> in %qD call is the same "
@@ -1064,8 +1067,9 @@ sizeof_pointer_memaccess_warning (location_t *sizeof_arg_loc, tree callee,
                        "argument to %<sizeof%> in %qD call is the same "
                        "expression as the second source; did you mean to "
                        "remove the addressof?", callee);
-         else if ((TYPE_PRECISION (TREE_TYPE (type))
-                   == TYPE_PRECISION (char_type_node))
+         else if ((INTEGRAL_TYPE_P (TREE_TYPE (type))
+                   && (TYPE_PRECISION (TREE_TYPE (type))
+                       == TYPE_PRECISION (char_type_node)))
                   || strop)
            warning_at (loc, OPT_Wsizeof_pointer_memaccess,
                        "argument to %<sizeof%> in %qD call is the same "

diff --git a/gcc/testsuite/c-c++-common/Wsizeof-pointer-memaccess5.c b/gcc/testsuite/c-c++-common/Wsizeof-pointer-memaccess5.c
new file mode 100644 (file)
index 0000000..aaa7da0
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/Wsizeof-pointer-memaccess5.c
@@ -0,0 +1,29 @@
+/* PR c/117230 */
+/* { dg-do compile } */
+/* { dg-options "-Wsizeof-pointer-memaccess" } */
+
+typedef int V __attribute__((vector_size (sizeof (int))));
+
+void
+foo (V *a, char *b)
+{
+  __builtin_memcpy (b, a, sizeof (a));         /* { dg-warning "argument to 'sizeof' in '\[^\n\r]*__builtin_memcpy\[^\n\r]*' call is the same expression as the source; did you mean to dereference it\\\?" } */
+}
+
+void
+bar (V *a, char *b)
+{
+  __builtin_memcpy (a, b, sizeof (a));         /* { dg-warning "argument to 'sizeof' in '\[^\n\r]*__builtin_memcpy\[^\n\r]*' call is the same expression as the destination; did you mean to dereference it\\\?" } */
+}
+
+int
+baz (V *a, char *b)
+{
+  return __builtin_memcmp (a, b, sizeof (a));  /* { dg-warning "argument to 'sizeof' in '\[^\n\r]*__builtin_memcmp\[^\n\r]*' call is the same expression as the first source; did you mean to dereference it\\\?" } */
+}
+
+int
+qux (V *a, char *b)
+{
+  return __builtin_memcmp (b, a, sizeof (a));  /* { dg-warning "argument to 'sizeof' in '\[^\n\r]*__builtin_memcmp\[^\n\r]*' call is the same expression as the second source; did you mean to dereference it\\\?" } */
+}