[clang] [clang-cl] Fix value of __FUNCTION__ in MSVC mode. (PR #84014)

[via cfe-commits]

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@@ -721,10 +722,17 @@ std::string PredefinedExpr::ComputeName(PredefinedIdentKind IK,
     return std::string(Out.str());
   }
   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurrentDecl)) {
-    if (IK != PredefinedIdentKind::PrettyFunction &&
-        IK != PredefinedIdentKind::PrettyFunctionNoVirtual &&
-        IK != PredefinedIdentKind::FuncSig &&
-        IK != PredefinedIdentKind::LFuncSig)
+    const auto &LO = Context.getLangOpts();
+    if ((ForceElaboratedPrinting &&
+         (((IK == PredefinedIdentKind::Func ||
+            IK == PredefinedIdentKind ::Function) &&
+           !LO.MicrosoftExt) ||
+          (IK == PredefinedIdentKind::LFunction && LO.MicrosoftExt))) ||
+        (!ForceElaboratedPrinting &&
+         (IK != PredefinedIdentKind::PrettyFunction &&
+          IK != PredefinedIdentKind::PrettyFunctionNoVirtual &&
+          IK != PredefinedIdentKind::FuncSig &&
+          IK != PredefinedIdentKind::LFuncSig)))
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Sirraide wrote:

Also, afaik you’re supposed to use `MSVCCompat`, not `MicrosoftExt` to check if we’re in ‘MSVC  mode’, if you will. This isn’t really an ‘extension’ that would otherwise be disabled, so I don’t think `MicrosoftExt` is the right thing here.

https://github.com/llvm/llvm-project/pull/84014