[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
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index e01ca14..762f441 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -2743,6 +2743,34 @@
case Intrinsic::aarch64_neon_umin:
return DAG.getNode(ISD::UMIN, dl, Op.getValueType(),
Op.getOperand(1), Op.getOperand(2));
+
+ case Intrinsic::localaddress: {
+ // Returns one of the stack, base, or frame pointer registers, depending on
+ // which is used to reference local variables.
+ MachineFunction &MF = DAG.getMachineFunction();
+ const AArch64RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
+ unsigned Reg;
+ if (RegInfo->hasBasePointer(MF))
+ Reg = RegInfo->getBaseRegister();
+ else // This function handles the SP or FP case.
+ Reg = RegInfo->getFrameRegister(MF);
+ return DAG.getCopyFromReg(DAG.getEntryNode(), dl, Reg,
+ Op.getSimpleValueType());
+ }
+
+ case Intrinsic::eh_recoverfp: {
+ // FIXME: This needs to be implemented to correctly handle highly aligned
+ // stack objects. For now we simply return the incoming FP. Refer D53541
+ // for more details.
+ SDValue FnOp = Op.getOperand(1);
+ SDValue IncomingFPOp = Op.getOperand(2);
+ GlobalAddressSDNode *GSD = dyn_cast<GlobalAddressSDNode>(FnOp);
+ auto *Fn = dyn_cast_or_null<Function>(GSD ? GSD->getGlobal() : nullptr);
+ if (!Fn)
+ report_fatal_error(
+ "llvm.eh.recoverfp must take a function as the first argument");
+ return IncomingFPOp;
+ }
}
}