[llvm][ARM][AArch64] Add attributes to synthetic functions. (#83153)

Module flags represent the original intention.

Depends on #82819

1 files changed, 29 insertions, 0 deletions

diff --git a/llvm/lib/IR/Function.cpp b/llvm/lib/IR/Function.cpp
index 5fb348a8..2087198 100644
--- a/llvm/lib/IR/Function.cpp
+++ b/llvm/lib/IR/Function.cpp
@@ -407,6 +407,35 @@ Function *Function::createWithDefaultAttr(FunctionType *Ty,
   StringRef DefaultFeatures = F->getContext().getDefaultTargetFeatures();
   if (!DefaultFeatures.empty())
     B.addAttribute("target-features", DefaultFeatures);
+
+  // Check if the module attribute is present and not zero.
+  auto isModuleAttributeSet = [&](const StringRef &ModAttr) -> bool {
+    const auto *Attr =
+        mdconst::extract_or_null<ConstantInt>(M->getModuleFlag(ModAttr));
+    return Attr && !Attr->isZero();
+  };
+
+  auto AddAttributeIfSet = [&](const StringRef &ModAttr) {
+    if (isModuleAttributeSet(ModAttr))
+      B.addAttribute(ModAttr);
+  };
+
+  StringRef SignType = "none";
+  if (isModuleAttributeSet("sign-return-address"))
+    SignType = "non-leaf";
+  if (isModuleAttributeSet("sign-return-address-all"))
+    SignType = "all";
+  if (SignType != "none") {
+    B.addAttribute("sign-return-address", SignType);
+    B.addAttribute("sign-return-address-key",
+                   isModuleAttributeSet("sign-return-address-with-bkey")
+                       ? "b_key"
+                       : "a_key");
+  }
+  AddAttributeIfSet("branch-target-enforcement");
+  AddAttributeIfSet("branch-protection-pauth-lr");
+  AddAttributeIfSet("guarded-control-stack");
+
   F->addFnAttrs(B);
   return F;
 }