[llvm-branch-commits] [llvm] [AArch64][PAC] Lower authenticated calls with ptrauth bundles. (PR #85736)

[Daniil Kovalev via llvm-branch-commits]

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@@ -8410,17 +8447,57 @@ AArch64TargetLowering::LowerCall(CallLoweringInfo &CLI,
     InGlue = Chain.getValue(1);
   }
 
+  unsigned Opc = IsTailCall ? AArch64ISD::TC_RETURN : AArch64ISD::CALL;
+
   std::vector<SDValue> Ops;
   Ops.push_back(Chain);
   Ops.push_back(Callee);
 
+  // Calls with operand bundle "clang.arc.attachedcall" are special. They should
+  // be expanded to the call, directly followed by a special marker sequence and
+  // a call to an ObjC library function.  Use CALL_RVMARKER to do that.
+  if (CLI.CB && objcarc::hasAttachedCallOpBundle(CLI.CB)) {
+    assert(!IsTailCall &&
+           "tail calls cannot be marked with clang.arc.attachedcall");
+    Opc = AArch64ISD::CALL_RVMARKER;
+
+    // Add a target global address for the retainRV/claimRV runtime function
+    // just before the call target.
+    Function *ARCFn = *objcarc::getAttachedARCFunction(CLI.CB);
+    auto GA = DAG.getTargetGlobalAddress(ARCFn, DL, PtrVT);
+    Ops.insert(Ops.begin() + 1, GA);
+  } else if (CallConv == CallingConv::ARM64EC_Thunk_X64) {
+    Opc = AArch64ISD::CALL_ARM64EC_TO_X64;
+  } else if (GuardWithBTI)
+    Opc = AArch64ISD::CALL_BTI;
+
   if (IsTailCall) {
     // Each tail call may have to adjust the stack by a different amount, so
     // this information must travel along with the operation for eventual
     // consumption by emitEpilogue.
     Ops.push_back(DAG.getTargetConstant(FPDiff, DL, MVT::i32));
   }
 
+  if (CLI.PAI) {
+    const uint64_t Key = CLI.PAI->Key;
+    // Authenticated calls only support IA and IB.
+    if (Key > 1)
+      report_fatal_error("Unsupported key kind for authenticating call");
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kovdan01 wrote:

Please add a test for the error message

https://github.com/llvm/llvm-project/pull/85736