Add the support in code-gen for the landingpad instruction lowering.

The landingpad instruction is lowered into the EXCEPTIONADDR and EHSELECTION
SDNodes. The information from the landingpad instruction is harvested by the
'AddLandingPadInfo' function. The new EH uses the current EH scheme in the
back-end. This will change once we switch over to the new scheme. (Reviewed by
Jakob!)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137880 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 70 insertions, 3 deletions

diff --git a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index d5bf12055e..10b251d1bf 100644
--- a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -454,3 +454,34 @@ void llvm::CopyCatchInfo(const BasicBlock *SuccBB, const BasicBlock *LPad,
       break;
   }
 }
+
+/// AddLandingPadInfo - Extract the exception handling information from the
+/// landingpad instruction and add them to the specified machine module info.
+void llvm::AddLandingPadInfo(const LandingPadInst &I, MachineModuleInfo &MMI,
+                             MachineBasicBlock *MBB) {
+  MMI.addPersonality(MBB,
+                     cast<Function>(I.getPersonalityFn()->stripPointerCasts()));
+
+  if (I.isCleanup())
+    MMI.addCleanup(MBB);
+
+  // FIXME: New EH - Add the clauses in reverse order. This isn't 100% correct,
+  //        but we need to do it this way because of how the DWARF EH emitter
+  //        processes the clauses.
+  for (unsigned i = I.getNumClauses(); i != 0; --i) {
+    Value *Val = I.getClause(i - 1);
+    if (I.isCatch(i - 1)) {
+      MMI.addCatchTypeInfo(MBB,
+                           dyn_cast<GlobalVariable>(Val->stripPointerCasts()));
+    } else {
+      // Add filters in a list.
+      Constant *CVal = cast<Constant>(Val);
+      SmallVector<const GlobalVariable*, 4> FilterList;
+      for (User::op_iterator
+             II = CVal->op_begin(), IE = CVal->op_end(); II != IE; ++II)
+        FilterList.push_back(cast<GlobalVariable>((*II)->stripPointerCasts()));
+
+      MMI.addFilterTypeInfo(MBB, FilterList);
+    }
+  }
+}
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index c1d533582f..66a9aab76c 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1814,6 +1814,45 @@ void SelectionDAGBuilder::visitResume(const ResumeInst &RI) {
   llvm_unreachable("SelectionDAGBuilder shouldn't visit resume instructions!");
 }
 
+void SelectionDAGBuilder::visitLandingPad(const LandingPadInst &LP) {
+  assert(FuncInfo.MBB->isLandingPad() &&
+         "Call to landingpad not in landing pad!");
+
+  MachineBasicBlock *MBB = FuncInfo.MBB;
+  MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
+  AddLandingPadInfo(LP, MMI, MBB);
+
+  SmallVector<EVT, 2> ValueVTs;
+  ComputeValueVTs(TLI, LP.getType(), ValueVTs);
+
+  // Insert the EXCEPTIONADDR instruction.
+  assert(FuncInfo.MBB->isLandingPad() &&
+         "Call to eh.exception not in landing pad!");
+  SDVTList VTs = DAG.getVTList(TLI.getPointerTy(), MVT::Other);
+  SDValue Ops[2];
+  Ops[0] = DAG.getRoot();
+  SDValue Op1 = DAG.getNode(ISD::EXCEPTIONADDR, getCurDebugLoc(), VTs, Ops, 1);
+  SDValue Chain = Op1.getValue(1);
+
+  // Insert the EHSELECTION instruction.
+  VTs = DAG.getVTList(TLI.getPointerTy(), MVT::Other);
+  Ops[0] = Op1;
+  Ops[1] = Chain;
+  SDValue Op2 = DAG.getNode(ISD::EHSELECTION, getCurDebugLoc(), VTs, Ops, 2);
+  Chain = Op2.getValue(1);
+  Op2 = DAG.getSExtOrTrunc(Op2, getCurDebugLoc(), MVT::i32);
+
+  Ops[0] = Op1;
+  Ops[1] = Op2;
+  SDValue Res = DAG.getNode(ISD::MERGE_VALUES, getCurDebugLoc(),
+                            DAG.getVTList(&ValueVTs[0], ValueVTs.size()),
+                            &Ops[0], 2);
+
+  std::pair<SDValue, SDValue> RetPair = std::make_pair(Res, Chain);
+  setValue(&LP, RetPair.first);
+  DAG.setRoot(RetPair.second);
+}
+
 /// handleSmallSwitchCaseRange - Emit a series of specific tests (suitable for
 /// small case ranges).
 bool SelectionDAGBuilder::handleSmallSwitchRange(CaseRec& CR,
@@ -2985,9 +3024,6 @@ void SelectionDAGBuilder::visitExtractValue(const ExtractValueInst &I) {
                            &Values[0], NumValValues));
 }
 
-void SelectionDAGBuilder::visitLandingPad(const LandingPadInst &I) {
-}
-
 void SelectionDAGBuilder::visitGetElementPtr(const User &I) {
   SDValue N = getValue(I.getOperand(0));
   Type *Ty = I.getOperand(0)->getType();