[clang] [Clang] Add [[clang::complete_on_member_instantiation]] (PR #211231)

[Louis Dionne via cfe-commits]

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@@ -0,0 +1,49 @@
+// RUN: %clang_cc1 %s -verify -fsyntax-only
+
+template <class T>
+struct [[clang::complete_on_member_instantiation]] S1 {}; // expected-error {{'clang::complete_on_member_instantiation' attribute takes one argument}}
+
+template <class T>
+struct [[clang::complete_on_member_instantiation(1)]] S2 {}; // expected-error {{expected a type}}
+
+template <class T>
+struct [[clang::complete_on_member_instantiation(T)]] RequiresComplete {
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ldionne wrote:

Are variadic parameters supported? This probably deserves a test.

https://github.com/llvm/llvm-project/pull/211231