[clang] [llvm] [llvm][AArch64] Do not inline a function with different signing scheme. (PR #80642)

[Nick Desaulniers via cfe-commits]

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@@ -5167,6 +5199,41 @@ void llvm::UpgradeFunctionAttributes(Function &F) {
   F.removeRetAttrs(AttributeFuncs::typeIncompatible(F.getReturnType()));
   for (auto &Arg : F.args())
     Arg.removeAttrs(AttributeFuncs::typeIncompatible(Arg.getType()));
+
+  if (!ModuleMetadataIsMaterialized)
+    return;
+  if (F.isDeclaration())
+    return;
+  Module *M = F.getParent();
+  if (!M)
+    return;
+
+  Triple T(M->getTargetTriple());
+  // Convert module level attributes to function level attributes because
+  // after merging modules the attributes might change and would have different
+  // effect on the functions as the original module would have.
+  if (T.isThumb() || T.isARM() || T.isAArch64()) {
+    if (!F.hasFnAttribute("sign-return-address")) {
+      StringRef SignType = "none";
+      if (const auto *Sign = mdconst::extract_or_null<ConstantInt>(
+              M->getModuleFlag("sign-return-address")))
+        if (Sign->getZExtValue())
+          SignType = "non-leaf";
+
+      if (const auto *SignAll = mdconst::extract_or_null<ConstantInt>(
+              M->getModuleFlag("sign-return-address-all")))
+        if (SignAll->getZExtValue())
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nickdesaulniers wrote:

This pattern appears a lot; consider using a small static helper function.

https://github.com/llvm/llvm-project/pull/80642