1 files changed, 82 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp b/contrib/llvm-project/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
index a37e38072554..41343ba9700c 100644
--- a/contrib/llvm-project/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
+++ b/contrib/llvm-project/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
@@ -14,6 +14,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "AArch64MachineFunctionInfo.h"
+#include "AArch64InstrInfo.h"
+#include <llvm/IR/Metadata.h>
+#include <llvm/IR/Module.h>
 
 using namespace llvm;
 
@@ -30,3 +33,82 @@ void AArch64FunctionInfo::initializeBaseYamlFields(
   if (YamlMFI.HasRedZone.hasValue())
     HasRedZone = YamlMFI.HasRedZone;
 }
+
+static std::pair<bool, bool> GetSignReturnAddress(const Function &F) {
+  // The function should be signed in the following situations:
+  // - sign-return-address=all
+  // - sign-return-address=non-leaf and the functions spills the LR
+  if (!F.hasFnAttribute("sign-return-address")) {
+    const Module &M = *F.getParent();
+    if (const auto *Sign = mdconst::extract_or_null<ConstantInt>(
+            M.getModuleFlag("sign-return-address"))) {
+      if (Sign->getZExtValue()) {
+        if (const auto *All = mdconst::extract_or_null<ConstantInt>(
+                M.getModuleFlag("sign-return-address-all")))
+          return {true, All->getZExtValue()};
+        return {true, false};
+      }
+    }
+    return {false, false};
+  }
+
+  StringRef Scope = F.getFnAttribute("sign-return-address").getValueAsString();
+  if (Scope.equals("none"))
+    return {false, false};
+
+  if (Scope.equals("all"))
+    return {true, true};
+
+  assert(Scope.equals("non-leaf"));
+  return {true, false};
+}
+
+static bool ShouldSignWithBKey(const Function &F) {
+  if (!F.hasFnAttribute("sign-return-address-key")) {
+    if (const auto *BKey = mdconst::extract_or_null<ConstantInt>(
+            F.getParent()->getModuleFlag("sign-return-address-with-bkey")))
+      return BKey->getZExtValue();
+    return false;
+  }
+
+  const StringRef Key =
+      F.getFnAttribute("sign-return-address-key").getValueAsString();
+  assert(Key.equals_lower("a_key") || Key.equals_lower("b_key"));
+  return Key.equals_lower("b_key");
+}
+
+AArch64FunctionInfo::AArch64FunctionInfo(MachineFunction &MF) : MF(MF) {
+  // If we already know that the function doesn't have a redzone, set
+  // HasRedZone here.
+  if (MF.getFunction().hasFnAttribute(Attribute::NoRedZone))
+    HasRedZone = false;
+
+  const Function &F = MF.getFunction();
+  std::tie(SignReturnAddress, SignReturnAddressAll) = GetSignReturnAddress(F);
+  SignWithBKey = ShouldSignWithBKey(F);
+
+  if (!F.hasFnAttribute("branch-target-enforcement")) {
+    if (const auto *BTE = mdconst::extract_or_null<ConstantInt>(
+            F.getParent()->getModuleFlag("branch-target-enforcement")))
+      BranchTargetEnforcement = BTE->getZExtValue();
+    return;
+  }
+
+  const StringRef BTIEnable = F.getFnAttribute("branch-target-enforcement").getValueAsString();
+  assert(BTIEnable.equals_lower("true") || BTIEnable.equals_lower("false"));
+  BranchTargetEnforcement = BTIEnable.equals_lower("true");
+}
+
+bool AArch64FunctionInfo::shouldSignReturnAddress(bool SpillsLR) const {
+  if (!SignReturnAddress)
+    return false;
+  if (SignReturnAddressAll)
+    return true;
+  return SpillsLR;
+}
+
+bool AArch64FunctionInfo::shouldSignReturnAddress() const {
+  return shouldSignReturnAddress(llvm::any_of(
+      MF.getFrameInfo().getCalleeSavedInfo(),
+      [](const auto &Info) { return Info.getReg() == AArch64::LR; }));
+}