[COFF, ARM64] Implement support for SEH extensions __try/__except/__finally

Summary:
This patch supports MS SEH extensions __try/__except/__finally. The intrinsics localescape and localrecover are responsible for communicating escaped static allocas from the try block to the handler.

We need to preserve frame pointers for SEH. So we create a new function/property HasLocalEscape.

Reviewers: rnk, compnerd, mstorsjo, TomTan, efriedma, ssijaric

Reviewed By: rnk, efriedma

Subscribers: smeenai, jrmuizel, alex, majnemer, ssijaric, ehsan, dmajor, kristina, javed.absar, kristof.beyls, chrib, llvm-commits

Differential Revision: https://reviews.llvm.org/D53540

llvm-svn: 351370

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64RegisterInfo.cpp b/llvm/lib/Target/AArch64/AArch64RegisterInfo.cpp
index 96ae45ae3d0..3daac23592d 100644
--- a/llvm/lib/Target/AArch64/AArch64RegisterInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64RegisterInfo.cpp
@@ -466,6 +466,13 @@ void AArch64RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
 
   // Modify MI as necessary to handle as much of 'Offset' as possible
   Offset = TFI->resolveFrameIndexReference(MF, FrameIndex, FrameReg);
+
+  if (MI.getOpcode() == TargetOpcode::LOCAL_ESCAPE) {
+    MachineOperand &FI = MI.getOperand(FIOperandNum);
+    FI.ChangeToImmediate(Offset);
+    return;
+  }
+
   if (rewriteAArch64FrameIndex(MI, FIOperandNum, FrameReg, Offset, TII))
     return;