Add a warning (-Wnon-pod-memset) for calls to memset() with
a destination pointer that points to a non-POD type. This can flag such
horrible bugs as overwriting vptrs when a previously POD structure is
suddenly given a virtual method, or creating objects that crash on
practically any use by zero-ing out a member when its changed from
a const char* to a std::string, etc.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@130299 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/SemaCXX/warn-non-pod-memset.cpp b/test/SemaCXX/warn-non-pod-memset.cpp
new file mode 100644
index 0000000..03e626e
--- /dev/null
+++ b/test/SemaCXX/warn-non-pod-memset.cpp
@@ -0,0 +1,45 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+extern void *memset(void *, int, unsigned);
+
+// Several POD types that should not warn.
+struct S1 {} s1;
+struct S2 { int x; } s2;
+struct S3 { float x, y; S1 s[4]; void (*f)(S1**); } s3;
+
+// Non-POD types that should warn.
+struct X1 { X1(); } x1;
+struct X2 { ~X2(); } x2;
+struct X3 { virtual void f(); } x3;
+struct X4 : X2 {} x4;
+struct X5 : virtual S1 {} x5;
+
+void test_warn() {
+ memset(&x1, 0, sizeof x1); // \
+ // expected-warning {{destination for this memset call is a pointer to a non-POD type}} \
+ // expected-note {{explicitly cast the pointer to silence this warning}}
+ memset(&x2, 0, sizeof x2); // \
+ // expected-warning {{destination for this memset call is a pointer to a non-POD type}} \
+ // expected-note {{explicitly cast the pointer to silence this warning}}
+ memset(&x3, 0, sizeof x3); // \
+ // expected-warning {{destination for this memset call is a pointer to a non-POD type}} \
+ // expected-note {{explicitly cast the pointer to silence this warning}}
+ memset(&x4, 0, sizeof x4); // \
+ // expected-warning {{destination for this memset call is a pointer to a non-POD type}} \
+ // expected-note {{explicitly cast the pointer to silence this warning}}
+ memset(&x5, 0, sizeof x5); // \
+ // expected-warning {{destination for this memset call is a pointer to a non-POD type}} \
+ // expected-note {{explicitly cast the pointer to silence this warning}}
+}
+
+void test_nowarn() {
+ memset(&s1, 0, sizeof s1);
+ memset(&s2, 0, sizeof s2);
+ memset(&s3, 0, sizeof s3);
+
+ // Unevaluated code shouldn't warn.
+ (void)sizeof memset(&x1, 0, sizeof x1);
+
+ // Dead code shouldn't warn.
+ if (false) memset(&x1, 0, sizeof x1);
+}