[clang] [Clang][AArch64] Warn when calling streaming/non-streaming about vect… (PR #79842)

[Sander de Smalen via cfe-commits]

================
@@ -12236,6 +12236,23 @@ bool Sema::CheckFunctionDeclaration(Scope *S, FunctionDecl *NewFD,
     bool UsesSM = NewFD->hasAttr<ArmLocallyStreamingAttr>();
     bool UsesZA = Attr && Attr->isNewZA();
     bool UsesZT0 = Attr && Attr->isNewZT0();
+
+    if (UsesSM) {
+      if (NewFD->getReturnType()->isSizelessVectorType())
+        Diag(NewFD->getLocation(),
+             diag::warn_sme_locally_streaming_has_vl_args_returns);
+      auto *FPT = NewFD->getType()->castAs<FunctionProtoType>();
+      bool AnyScalableArgs = false;
+      for (QualType T : FPT->param_types()) {
+        if (T->isSizelessVectorType()) {
+          AnyScalableArgs = true;
+          break;
+        }
+      }
+      if (AnyScalableArgs)
+        Diag(NewFD->getLocation(),
+             diag::warn_sme_locally_streaming_has_vl_args_returns);
----------------
sdesmalen-arm wrote:

Can this be written like something along the lines of:
```
if (NewFD->getReturnType()->isSizelessVectorType() ||
    llvm::any_of(FPT->param_types(), [](QualType T) { return T->isSizelessVectorType(); }))
 Diag(....);
```
?

https://github.com/llvm/llvm-project/pull/79842