Disable use of _ExtInt with '__atomic' builtins
We're (temporarily) disabling ExtInt for the '__atomic' builtins so we can better design their behavior later. The idea is until we do an audit/design for the way atomic builtins are supposed to work with _ExtInt, we should leave them restricted so they don't limit our future options, such as by binding us to a sub-optimal implementation via ABI.
Example after this change:
$ cat test.c
void f(_ExtInt(64) *ptr) {
__atomic_fetch_add(ptr, 1, 0);
}
$ clang -c test.c
test.c:2:22: error: argument to atomic builtin of type '_ExtInt' is not supported
__atomic_fetch_add(ptr, 1, 0);
^
1 error generated.
Differential Revision: https://reviews.llvm.org/D84049
GitOrigin-RevId: ca77ab494aa29f7521ff797d230cd1b36cbe4e62
diff --git a/test/libcxx/atomics/ext-int.verify.cpp b/test/libcxx/atomics/ext-int.verify.cpp
new file mode 100644
index 0000000..3f57437
--- /dev/null
+++ b/test/libcxx/atomics/ext-int.verify.cpp
@@ -0,0 +1,11 @@
+// REQUIRES: clang-11
+
+#include <atomic>
+
+int main(int, char**)
+{
+ // expected-error@atomic:*1 {{_Atomic cannot be applied to integer type '_ExtInt(32)'}}
+ std::atomic<_ExtInt(32)> x {42};
+
+ return 0;
+}
