[clang] [Clang] restrict use of attribute names reserved by the C++ standard (PR #106036)

[Aaron Ballman via cfe-commits]

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@@ -0,0 +1,33 @@
+// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx11 -pedantic -std=c++11 %s
+// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx14 -pedantic -std=c++14 %s
+// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx17 -pedantic -std=c++17 %s
+// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx20 -pedantic -std=c++20 %s
+// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx23 -pedantic -std=c++23 %s
+// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx26 -pedantic -std=c++26 %s
+
+#define noreturn 1           // cxx11-warning {{keyword is hidden by macro definition}}
+#undef noreturn
+
+#define carries_dependency 1 // cxx11-warning {{keyword is hidden by macro definition}}
+#undef carries_dependency
+
+#define deprecated 1         // cxx14-warning {{keyword is hidden by macro definition}}
+#undef deprecated
+
+#define fallthrough 1        // cxx17-warning {{keyword is hidden by macro definition}}
+#undef fallthrough
+
+#define maybe_unused 1       // cxx17-warning {{keyword is hidden by macro definition}}
+#undef maybe_unused
+
+#define nodiscard 1          // cxx17-warning {{keyword is hidden by macro definition}}
+#undef nodiscard
+
+#define no_unique_address 1  // cxx20-warning {{keyword is hidden by macro definition}}
+#undef no_unique_address
+
+#define assume 1             // cxx23-warning {{keyword is hidden by macro definition}}
+#undef assume
+
+#define indeterminate 1      // cxx26-warning {{keyword is hidden by macro definition}}
+#undef indeterminate
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AaronBallman wrote:

Please add test cases that show we diagnose `#define likely` but not `#define likely()` (and same for `unlikely`).

https://github.com/llvm/llvm-project/pull/106036