Poison builds that accidentally use both the Upb and Cpp kernel. This…

… should only be possible for targets defined within the protobuf codebase. PiperOrigin-RevId: 642622844
protocolbuffers · Jun 12, 2024 · 41315fd · 41315fd
1 parent 94d5f12
commit 41315fd
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/rust/shared.rs b/rust/shared.rs
@@ -61,6 +61,11 @@ mod proxied;
 mod repeated;
 mod string;
 
+// If the Upb and C++ kernels are both linked into the same binary, this symbol
+// will be defined twice and cause a link error.
+#[no_mangle]
+extern "C" fn __Disallow_Upb_And_Cpp_In_Same_Binary() {}
+
 /// An error that happened during parsing.
 #[derive(Debug, Clone)]
 pub struct ParseError;