[PATCH] D134475: [clang-cl] Add support for [[msvc::constexpr]] C++11 attribute

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith added inline comments.


================
Comment at: clang/lib/AST/ExprConstant.cpp:5615-5627
+    if (canEvalMSConstexpr || isMSConstexpr) {
+      // Diagnose invalid usage of [[msvc::constexpr]] function
+      bool isConstructor = isa<CXXConstructorDecl>(Definition);
+      if (canEvalMSConstexpr) { // !isMSConstexpr
+        Info.FFDiag(CallLoc, diag::note_constexpr_invalid_function, 1)
+            << /*IsConstexpr*/ 0 << isConstructor << Definition;
+        Info.Note(Definition->getLocation(), diag::note_declared_at);
----------------
Given that the intended use case is for usage behind the scenes in the standard library, I don't think we should be changing our diagnostic output at all here. If the library, as an implementation detail, marks a non-`constexpr` function as `[[msvc::constexpr]]`, we shouldn't tell the user to add `[[msvc::constexpr]]` to their code to allow it to be called, after all, the annotation is an implementation detail of the MS standard library.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D134475/new/

https://reviews.llvm.org/D134475