From fdd089aa14d90fcf220d54fb3fbfd2170f89de78 Mon Sep 17 00:00:00 2001
From: Amara Emerson <aemerson@apple.com>
Date: Thu, 26 Jul 2018 01:25:58 +0000
Subject: [PATCH] [GlobalISel] Fall back to SDISel for swifterror/swiftself
 attributes.

We don't currently support these, fall back until we do.

llvm-svn: 337994
---
 llvm/lib/CodeGen/GlobalISel/CallLowering.cpp       |  3 +++
 llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp       | 15 ++++++++++++++
 .../CodeGen/AArch64/GlobalISel/arm64-fallback.ll   | 23 ++++++++++++++++++++++
 3 files changed, 41 insertions(+)

diff --git a/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp b/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
index 114c068..07de31b 100644
--- a/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
@@ -38,6 +38,9 @@ bool CallLowering::lowerCall(
     ArgInfo OrigArg{ArgRegs[i], Arg->getType(), ISD::ArgFlagsTy{},
                     i < NumFixedArgs};
     setArgFlags(OrigArg, i + AttributeList::FirstArgIndex, DL, CS);
+    // We don't currently support swifterror or swiftself args.
+    if (OrigArg.Flags.isSwiftError() || OrigArg.Flags.isSwiftSelf())
+      return false;
     OrigArgs.push_back(OrigArg);
     ++i;
   }
diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index d481220..bafb7a0 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -1157,6 +1157,9 @@ bool IRTranslator::translateAlloca(const User &U,
                                    MachineIRBuilder &MIRBuilder) {
   auto &AI = cast<AllocaInst>(U);
 
+  if (AI.isSwiftError())
+    return false;
+
   if (AI.isStaticAlloca()) {
     unsigned Res = getOrCreateVReg(AI);
     int FI = getOrCreateFrameIndex(AI);
@@ -1574,6 +1577,18 @@ bool IRTranslator::runOnMachineFunction(MachineFunction &CurMF) {
         MRI->createGenericVirtualRegister(getLLTForType(*Arg.getType(), *DL)));
   }
 
+  // We don't currently support translating swifterror or swiftself functions.
+  for (auto &Arg : F.args()) {
+    if (Arg.hasSwiftErrorAttr() || Arg.hasSwiftSelfAttr()) {
+      OptimizationRemarkMissed R("gisel-irtranslator", "GISelFailure",
+                                 F.getSubprogram(), &F.getEntryBlock());
+      R << "unable to lower arguments due to swifterror/swiftself: "
+        << ore::NV("Prototype", F.getType());
+      reportTranslationError(*MF, *TPC, *ORE, R);
+      return false;
+    }
+  }
+
   if (!CLI->lowerFormalArguments(EntryBuilder, F, VRegArgs)) {
     OptimizationRemarkMissed R("gisel-irtranslator", "GISelFailure",
                                F.getSubprogram(), &F.getEntryBlock());
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
index e0c8860..9c9d22d 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
@@ -235,3 +235,26 @@ define void @nonpow2_vector_add_fewerelements() {
   store i64 %ex, i64* undef
   ret void
 }
+
+%swift_error = type {i64, i8}
+
+; FALLBACK-WITH-REPORT-ERR: remark: <unknown>:0:0: unable to lower arguments due to swifterror/swiftself: void (%swift_error**)* (in function: swifterror_param)
+; FALLBACK-WITH-REPORT-ERR: warning: Instruction selection used fallback path for swifterror_param
+define void @swifterror_param(%swift_error** swifterror %error_ptr_ref) {
+  ret void
+}
+
+; FALLBACK-WITH-REPORT-ERR: remark: <unknown>:0:0: unable to translate instruction: alloca: '  %error_ptr_ref = alloca swifterror %swift_error*' (in function: swifterror_alloca)
+; FALLBACK-WITH-REPORT-ERR: warning: Instruction selection used fallback path for swifterror_alloca
+; We can't currently test the call parameters being swifterror because the value
+; must come from a swifterror alloca or parameter, at which point we already
+; fallback. As long as those cases work however we should be fine.
+define void @swifterror_alloca(i8* %error_ref) {
+entry:
+  %error_ptr_ref = alloca swifterror %swift_error*
+  store %swift_error* null, %swift_error** %error_ptr_ref
+  call void @swifterror_param(%swift_error** swifterror %error_ptr_ref)
+  ret void
+}
+
+
-- 
2.7.4