[PATCH] D64914: Implement P1771

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman added inline comments.


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Comment at: clang/lib/Sema/SemaStmt.cpp:296-301
+      if (A) {
+        StringRef Msg = A->getMessage();
+        if (!Msg.empty())
+          Diag(Loc, diag::warn_unused_constructor_msg) << A << Msg << R1 << R2;
+        else
+          Diag(Loc, diag::warn_unused_constructor) << A << R1 << R2;
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We use this pattern in a handful of places. I wonder if we want to add a private function to `Sema` to handle this: `void DiagnoseNodiscard(const WarnUnusedResultAttr *A, SourceLocation Loc, bool IsConstructor);` (maybe it could return a partial diagnostic so we can optionally apply the source ranges to it as well?)


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Comment at: clang/test/CXX/dcl.dcl/dcl.attr/dcl.attr.nodiscard/p2.cpp:91
+  operator ConvertTo();
+  [[nodiscard]] operator int();
+};
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Can you add a test that adds a message to the `nodiscard` attribute written directly on a conversion operator?


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  https://reviews.llvm.org/D64914/new/

https://reviews.llvm.org/D64914