[clang] [clang] Move warning about memset/memcpy to NonTriviallyCopyable type… (PR #117387)

[via cfe-commits]

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@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -Wnontrivial-memcall %s
+
+extern "C" void *memcpy(void *s1, const void *s2, unsigned n);
+
+class TriviallyCopyable {};
+class NonTriviallyCopyable { NonTriviallyCopyable(const NonTriviallyCopyable&);};
+struct Incomplete;
+
+void test_memcpy(TriviallyCopyable* tc0, TriviallyCopyable* tc1,
+                 NonTriviallyCopyable *ntc0, NonTriviallyCopyable *ntc1,
+                 Incomplete *i0, Incomplete *i1) {
+  // OK
+  memcpy(tc0, tc1, sizeof(*tc0));
+
+  // OK
+  memcpy(i0, i1, 10);
+
+  // expected-warning at +2{{first argument in call to 'memcpy' is a pointer to non-trivially copyable type 'NonTriviallyCopyable'}}
+  // expected-note at +1{{explicitly cast the pointer to silence this warning}}
+  memcpy(ntc0, ntc1, sizeof(*ntc0));
+
+  // ~ OK
+  memcpy((void*)ntc0, ntc1, sizeof(*ntc0));
+
+  // OK
+  memcpy((void*)ntc0, (void*)ntc1, sizeof(*ntc0));
+}
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serge-sans-paille wrote:

I wanted a test case that only used `-Wnontrivial-memcall`

https://github.com/llvm/llvm-project/pull/117387