New calling convention preserve_none

Report error when swift attribute is used with preserve_none at the same
time.

Author: weiguozhi

llvm/lib/Target/X86/X86ISelLoweringCall.cpp

@@ -1935,6 +1935,16 @@ SDValue X86TargetLowering::LowerFormalArguments(
       MRI.disableCalleeSavedRegister(Pair.first);
   }
 
+  if (CallingConv::PreserveNone == CallConv)
+    for (unsigned I = 0, E = Ins.size(); I != E; ++I) {
+      if (Ins[I].Flags.isSwiftSelf() || Ins[I].Flags.isSwiftAsync() ||
+          Ins[I].Flags.isSwiftError()) {
+        errorUnsupported(DAG, dl,
+                         "Swift attributes can't be used with preserve_none");
+        break;
+      }
+    }
+
   return Chain;
 }
 
@@ -2586,6 +2596,16 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
     InGlue = Chain.getValue(1);
   }
 
+  if (CallingConv::PreserveNone == CallConv)
+    for (unsigned I = 0, E = Outs.size(); I != E; ++I) {
+      if (Outs[I].Flags.isSwiftSelf() || Outs[I].Flags.isSwiftAsync() ||
+          Outs[I].Flags.isSwiftError()) {
+        errorUnsupported(DAG, dl,
+                         "Swift attributes can't be used with preserve_none");
+        break;
+      }
+    }
+
   // Handle result values, copying them out of physregs into vregs that we
   // return.
   return LowerCallResult(Chain, InGlue, CallConv, isVarArg, Ins, dl, DAG,

llvm/test/CodeGen/X86/preserve_none_swift.ll

@@ -0,0 +1,16 @@
+; RUN: not llc -mtriple=x86_64 %s -o - 2>&1 | FileCheck %s
+
+; Swift attributes should not be used with preserve_none.
+
+declare preserve_nonecc void @foo(ptr swiftself)
+
+; CHECK: error: <unknown>:0:0: in function bar void (ptr): Swift attributes can't be used with preserve_none
+define preserve_nonecc void @bar(ptr swifterror) {
+  ret void
+}
+
+; CHECK: error: <unknown>:0:0: in function qux void (ptr): Swift attributes can't be used with preserve_none
+define void @qux(ptr %addr) {
+  call preserve_nonecc void @foo(ptr swiftself %addr)
+  ret void
+}