[clang][bytecode] Check for overlapping memcpy regions (#119535)

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/test/AST/ByteCode/builtin-functions.cpp b/clang/test/AST/ByteCode/builtin-functions.cpp
index 7dd08cb..ef6faae 100644
--- a/clang/test/AST/ByteCode/builtin-functions.cpp
+++ b/clang/test/AST/ByteCode/builtin-functions.cpp
@@ -1207,4 +1207,19 @@ namespace BuiltinMemcpy {
   }
   static_assert(memcpyTypeRem() == 12); // both-error {{not an integral constant expression}} \
                                         // both-note {{in call to}}
+
+  template<typename T>
+  constexpr T result(T (&arr)[4]) {
+    return arr[0] * 1000 + arr[1] * 100 + arr[2] * 10 + arr[3];
+  }
+
+  constexpr int test_memcpy(int a, int b, int n) {
+    int arr[4] = {1, 2, 3, 4};
+    __builtin_memcpy(arr + a, arr + b, n); // both-note {{overlapping memory regions}}
+    return result(arr);
+  }
+
+  static_assert(test_memcpy(1, 2, sizeof(int)) == 1334);
+  static_assert(test_memcpy(0, 1, sizeof(int) * 2) == 2334); // both-error {{not an integral constant expression}} \
+                                                             // both-note {{in call}}
 }