[clang] [Clang][ARM][AArch64] Alway emit protection attributes for functions. (PR #82819)

[Nick Desaulniers via cfe-commits]

================
@@ -116,37 +116,22 @@ class AArch64TargetCodeGenInfo : public TargetCodeGenInfo {
     if (!FD)
       return;
 
-    const auto *TA = FD->getAttr<TargetAttr>();
-    if (TA == nullptr)
-      return;
-
-    ParsedTargetAttr Attr =
-        CGM.getTarget().parseTargetAttr(TA->getFeaturesStr());
-    if (Attr.BranchProtection.empty())
-      return;
-
-    TargetInfo::BranchProtectionInfo BPI;
-    StringRef Error;
-    (void)CGM.getTarget().validateBranchProtection(Attr.BranchProtection,
-                                                   Attr.CPU, BPI, Error);
-    assert(Error.empty());
-
-    auto *Fn = cast<llvm::Function>(GV);
-    Fn->addFnAttr("sign-return-address", BPI.getSignReturnAddrStr());
-
-    if (BPI.SignReturnAddr != LangOptions::SignReturnAddressScopeKind::None) {
-      Fn->addFnAttr("sign-return-address-key",
-                    BPI.SignKey == LangOptions::SignReturnAddressKeyKind::AKey
-                        ? "a_key"
-                        : "b_key");
+    TargetInfo::BranchProtectionInfo BPI(CGM.getLangOpts());
+
+    if (const auto *TA = FD->getAttr<TargetAttr>()) {
+      ParsedTargetAttr Attr =
+          CGM.getTarget().parseTargetAttr(TA->getFeaturesStr());
+      if (!Attr.BranchProtection.empty()) {
+        StringRef Error;
+        (void)CGM.getTarget().validateBranchProtection(Attr.BranchProtection,
+                                                       Attr.CPU, BPI, Error);
+#ifndef NDEBUG
+        assert(Error.empty());
+#endif
----------------
nickdesaulniers wrote:

No need for the preprocessor guard here, as `assert` only does anything if NDEBUG is not defined.

[My earlier suggestion](https://github.com/llvm/llvm-project/pull/82819#discussion_r1508064741) was to put it around this if statement, but I think that's a bad suggestion now since we want validateBranchProtection to run regardless of NDEBUG.

https://github.com/llvm/llvm-project/pull/82819