[CodeGen] Mark setjmp/catchret MBBs address-taken

Summary:
This ensures that BranchFolding (and similar) won't remove these blocks.

Also allow AsmPrinter::EmitBasicBlockStart to process MBBs which are
address-taken but do not have BBs that are address-taken, since otherwise
its call to getAddrLabelSymbolTableToEmit would fail an assertion on such
blocks.  I audited the other callers of getAddrLabelSymbolTableToEmit
(and getAddrLabelSymbol); they all have BBs known to be address-taken
except for the call through getAddrLabelSymbol from
WinException::create32bitRef; that call is actually now unreachable, so
I've removed it and updated the signature of create32bitRef.

This fixes PR25168.

Reviewers: majnemer, andrew.w.kaylor, rnk

Subscribers: pgavlin, llvm-commits

Differential Revision: http://reviews.llvm.org/D13774

llvm-svn: 251113

1 files changed, 3 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index a1a18fe6bd2..95cb76094ec 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -1178,6 +1178,9 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
           .addReg(ReturnReg)
           .addMBB(RestoreMBB);
     }
+    // Record that we've taken the address of RestoreMBB and no longer just
+    // reference it in a terminator.
+    RestoreMBB->setHasAddressTaken();
   }
 
   if (MBBI != MBB.end())