[clang] [Clang] Implement P3034R1 Module Declarations Shouldn’t be Macros (PR #90574)

[Michael Spencer via cfe-commits]

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@@ -0,0 +1,87 @@
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+// RUN: split-file %s %t
+
+// RUN: %clang_cc1 -std=c++20 %t/A.cppm -triple x86_64-linux-gnu -verify
+// RUN: %clang_cc1 -std=c++20 %t/B.cppm -triple x86_64-linux-gnu -verify
+// RUN: %clang_cc1 -std=c++20 %t/C.cppm -triple x86_64-linux-gnu -verify
+// RUN: %clang_cc1 -std=c++20 %t/D.cppm -triple x86_64-linux-gnu -verify
+// RUN: %clang_cc1 -std=c++20 %t/E.cppm -triple x86_64-linux-gnu -verify
+// RUN: %clang_cc1 -std=c++20 %t/F.cppm -triple x86_64-linux-gnu -verify
+// RUN: %clang_cc1 -std=c++20 %t/G.cppm -triple x86_64-linux-gnu -verify
+// RUN: %clang_cc1 -std=c++20 %t/H.cppm -triple x86_64-linux-gnu -verify
+// RUN: %clang_cc1 -std=c++20 %t/I.cppm -triple x86_64-linux-gnu -verify
+// RUN: %clang_cc1 -std=c++20 %t/J.cppm -triple x86_64-linux-gnu -verify
+
+//--- version.h
+#ifndef VERSION_H
+#define VERSION_H
+
+#define VERSION libv5
+#define A a
+#define B b
+#define C c
+#define FUNC_LIKE(X) function_like_##X
+#define ATTRS [[]]
+#define SEMICOLON ;
+
+#endif
+
+//--- A.cppm
+#include "version.h"
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Bigcheese wrote:

The module-file grammar prohibits this, but clang doesn't implement this restriction yet. https://eel.is/c++draft/cpp#nt:module-file

You need to have a `module;` decl before any preprocessor directives.

https://github.com/llvm/llvm-project/pull/90574