[WinEH] Avoid creating MBBs for LLVM BBs that cannot contain code

Typically these are catchpads, which hold data used to decide whether to
catch the exception or continue unwinding. We also shouldn't create MBBs
for catchendpads, cleanupendpads, or terminatepads, since no real code
can live in them.

This fixes a problem where MI passes (like the register allocator) would
try to put code into catchpad blocks, which are not executed by the
runtime. In the new world, blocks ending in invokes now have many
possible successors.

llvm-svn: 247102

1 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
index e9ca2d12e07..0bfa89d2ba1 100644
--- a/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
@@ -283,7 +283,7 @@ static void removeDuplicatesGCPtrs(SmallVectorImpl<const Value *> &Bases,
 /// call node. Also update NodeMap so that getValue(statepoint) will
 /// reference lowered call result
 static SDNode *
-lowerCallFromStatepoint(ImmutableStatepoint ISP, MachineBasicBlock *LandingPad,
+lowerCallFromStatepoint(ImmutableStatepoint ISP, const BasicBlock *EHPadBB,
                         SelectionDAGBuilder &Builder,
                         SmallVectorImpl<SDValue> &PendingExports) {
 
@@ -316,7 +316,7 @@ lowerCallFromStatepoint(ImmutableStatepoint ISP, MachineBasicBlock *LandingPad,
   SDValue ReturnValue, CallEndVal;
   std::tie(ReturnValue, CallEndVal) = Builder.lowerCallOperands(
       ISP.getCallSite(), ImmutableStatepoint::CallArgsBeginPos,
-      ISP.getNumCallArgs(), ActualCallee, DefTy, LandingPad,
+      ISP.getNumCallArgs(), ActualCallee, DefTy, EHPadBB,
       false /* IsPatchPoint */);
 
   SDNode *CallEnd = CallEndVal.getNode();
@@ -626,7 +626,7 @@ void SelectionDAGBuilder::visitStatepoint(const CallInst &CI) {
 }
 
 void SelectionDAGBuilder::LowerStatepoint(
-    ImmutableStatepoint ISP, MachineBasicBlock *LandingPad /*=nullptr*/) {
+    ImmutableStatepoint ISP, const BasicBlock *EHPadBB /*= nullptr*/) {
   // The basic scheme here is that information about both the original call and
   // the safepoint is encoded in the CallInst.  We create a temporary call and
   // lower it, then reverse engineer the calling sequence.
@@ -666,7 +666,7 @@ void SelectionDAGBuilder::LowerStatepoint(
 
   // Get call node, we will replace it later with statepoint
   SDNode *CallNode =
-      lowerCallFromStatepoint(ISP, LandingPad, *this, PendingExports);
+      lowerCallFromStatepoint(ISP, EHPadBB, *this, PendingExports);
 
   // Construct the actual GC_TRANSITION_START, STATEPOINT, and GC_TRANSITION_END
   // nodes with all the appropriate arguments and return values.