From 3cd00c17396dd786d533ba71dafdcab9a7694804 Mon Sep 17 00:00:00 2001 From: Matthias Braun Date: Thu, 16 Jul 2015 22:34:16 +0000 Subject: [PATCH] Fix __builtin_setjmp in combination with sjlj exception handling. llvm.eh.sjlj.setjmp was used as part of the SjLj exception handling style but is also used in clang to implement __builtin_setjmp. The ARM backend needs to output additional dispatch tables for the SjLj exception handling style, these tables however can't be emitted if llvm.eh.sjlj.setjmp is simply used for __builtin_setjmp and no actual landing pad blocks exist. To solve this issue a new llvm.eh.sjlj.setup_dispatch intrinsic is introduced which is used instead of llvm.eh.sjlj.setjmp in the SjLj exception handling lowering, so we can differentiate between the case where we actually need to setup a dispatch table and the case where we just need the __builtin_setjmp semantic. Differential Revision: http://reviews.llvm.org/D9313 llvm-svn: 242481 --- llvm/include/llvm/CodeGen/ISDOpcodes.h | 4 + llvm/include/llvm/IR/Intrinsics.td | 1 + llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp | 1 + .../CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 5 + .../CodeGen/SelectionDAG/SelectionDAGDumper.cpp | 1 + llvm/lib/CodeGen/SjLjEHPrepare.cpp | 10 +- llvm/lib/Target/ARM/ARMISelLowering.cpp | 22 +++- llvm/lib/Target/ARM/ARMISelLowering.h | 2 + llvm/lib/Target/ARM/ARMInstrInfo.td | 8 ++ llvm/test/CodeGen/ARM/setjmp_longjmp.ll | 113 +++++++++++++++++++++ 10 files changed, 157 insertions(+), 10 deletions(-) create mode 100644 llvm/test/CodeGen/ARM/setjmp_longjmp.ll diff --git a/llvm/include/llvm/CodeGen/ISDOpcodes.h b/llvm/include/llvm/CodeGen/ISDOpcodes.h index 8a4b779f..49c002b 100644 --- a/llvm/include/llvm/CodeGen/ISDOpcodes.h +++ b/llvm/include/llvm/CodeGen/ISDOpcodes.h @@ -108,6 +108,10 @@ namespace ISD { /// and returns an outchain. EH_SJLJ_LONGJMP, + /// OUTCHAIN = EH_SJLJ_SETUP_DISPATCH(INCHAIN) + /// The target initializes the dispatch table here. + EH_SJLJ_SETUP_DISPATCH, + /// TargetConstant* - Like Constant*, but the DAG does not do any folding, /// simplification, or lowering of the constant. They are used for constants /// which are known to fit in the immediate fields of their users, or for diff --git a/llvm/include/llvm/IR/Intrinsics.td b/llvm/include/llvm/IR/Intrinsics.td index af312be..83cfebe 100644 --- a/llvm/include/llvm/IR/Intrinsics.td +++ b/llvm/include/llvm/IR/Intrinsics.td @@ -455,6 +455,7 @@ let Properties = [IntrNoMem] in { def int_eh_sjlj_functioncontext : Intrinsic<[], [llvm_ptr_ty]>; def int_eh_sjlj_setjmp : Intrinsic<[llvm_i32_ty], [llvm_ptr_ty]>; def int_eh_sjlj_longjmp : Intrinsic<[], [llvm_ptr_ty], [IntrNoReturn]>; +def int_eh_sjlj_setup_dispatch : Intrinsic<[], []>; //===---------------- Generic Variable Attribute Intrinsics----------------===// // diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp index 51057a0..0396736 100644 --- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp @@ -1264,6 +1264,7 @@ void SelectionDAGLegalize::LegalizeOp(SDNode *Node) { case ISD::FRAME_TO_ARGS_OFFSET: case ISD::EH_SJLJ_SETJMP: case ISD::EH_SJLJ_LONGJMP: + case ISD::EH_SJLJ_SETUP_DISPATCH: // These operations lie about being legal: when they claim to be legal, // they should actually be expanded. Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0)); diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index 73de6e3..702e14b 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -4410,6 +4410,11 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) { getRoot(), getValue(I.getArgOperand(0)))); return nullptr; } + case Intrinsic::eh_sjlj_setup_dispatch: { + DAG.setRoot(DAG.getNode(ISD::EH_SJLJ_SETUP_DISPATCH, sdl, MVT::Other, + getRoot())); + return nullptr; + } case Intrinsic::masked_gather: visitMaskedGather(I); diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp index 8dabddc..883cc257 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp @@ -102,6 +102,7 @@ std::string SDNode::getOperationName(const SelectionDAG *G) const { case ISD::EH_RETURN: return "EH_RETURN"; case ISD::EH_SJLJ_SETJMP: return "EH_SJLJ_SETJMP"; case ISD::EH_SJLJ_LONGJMP: return "EH_SJLJ_LONGJMP"; + case ISD::EH_SJLJ_SETUP_DISPATCH: return "EH_SJLJ_SETUP_DISPATCH"; case ISD::ConstantPool: return "ConstantPool"; case ISD::TargetIndex: return "TargetIndex"; case ISD::ExternalSymbol: return "ExternalSymbol"; diff --git a/llvm/lib/CodeGen/SjLjEHPrepare.cpp b/llvm/lib/CodeGen/SjLjEHPrepare.cpp index d236e1f..2a16b64 100644 --- a/llvm/lib/CodeGen/SjLjEHPrepare.cpp +++ b/llvm/lib/CodeGen/SjLjEHPrepare.cpp @@ -50,7 +50,7 @@ class SjLjEHPrepare : public FunctionPass { Type *FunctionContextTy; Constant *RegisterFn; Constant *UnregisterFn; - Constant *BuiltinSetjmpFn; + Constant *BuiltinSetupDispatchFn; Constant *FrameAddrFn; Constant *StackAddrFn; Constant *StackRestoreFn; @@ -112,7 +112,8 @@ bool SjLjEHPrepare::doInitialization(Module &M) { FrameAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::frameaddress); StackAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::stacksave); StackRestoreFn = Intrinsic::getDeclaration(&M, Intrinsic::stackrestore); - BuiltinSetjmpFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setjmp); + BuiltinSetupDispatchFn = + Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setup_dispatch); LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda); CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite); FuncCtxFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_functioncontext); @@ -421,9 +422,8 @@ bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) { Val = Builder.CreateCall(StackAddrFn, {}, "sp"); Builder.CreateStore(Val, StackPtr, /*isVolatile=*/true); - // Call the setjmp instrinsic. It fills in the rest of the jmpbuf. - Value *SetjmpArg = Builder.CreateBitCast(JBufPtr, Builder.getInt8PtrTy()); - Builder.CreateCall(BuiltinSetjmpFn, SetjmpArg); + // Call the setup_dispatch instrinsic. It fills in the rest of the jmpbuf. + Builder.CreateCall(BuiltinSetupDispatchFn, {}); // Store a pointer to the function context so that the back-end will know // where to look for it. diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp index e335784..0a5d883 100644 --- a/llvm/lib/Target/ARM/ARMISelLowering.cpp +++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp @@ -849,11 +849,11 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM, // We want to custom lower some of our intrinsics. setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom); - if (Subtarget->isTargetDarwin()) { - setOperationAction(ISD::EH_SJLJ_SETJMP, MVT::i32, Custom); - setOperationAction(ISD::EH_SJLJ_LONGJMP, MVT::Other, Custom); + setOperationAction(ISD::EH_SJLJ_SETJMP, MVT::i32, Custom); + setOperationAction(ISD::EH_SJLJ_LONGJMP, MVT::Other, Custom); + setOperationAction(ISD::EH_SJLJ_SETUP_DISPATCH, MVT::Other, Custom); + if (Subtarget->isTargetDarwin()) setLibcallName(RTLIB::UNWIND_RESUME, "_Unwind_SjLj_Resume"); - } setOperationAction(ISD::SETCC, MVT::i32, Expand); setOperationAction(ISD::SETCC, MVT::f32, Expand); @@ -1069,7 +1069,8 @@ const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const { case ARMISD::VMOVDRR: return "ARMISD::VMOVDRR"; case ARMISD::EH_SJLJ_SETJMP: return "ARMISD::EH_SJLJ_SETJMP"; - case ARMISD::EH_SJLJ_LONGJMP:return "ARMISD::EH_SJLJ_LONGJMP"; + case ARMISD::EH_SJLJ_LONGJMP: return "ARMISD::EH_SJLJ_LONGJMP"; + case ARMISD::EH_SJLJ_SETUP_DISPATCH: return "ARMISD::EH_SJLJ_SETUP_DISPATCH"; case ARMISD::TC_RETURN: return "ARMISD::TC_RETURN"; @@ -2722,6 +2723,13 @@ ARMTargetLowering::LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const { Op.getOperand(1), DAG.getConstant(0, dl, MVT::i32)); } +SDValue ARMTargetLowering::LowerEH_SJLJ_SETUP_DISPATCH(SDValue Op, + SelectionDAG &DAG) const { + SDLoc dl(Op); + return DAG.getNode(ARMISD::EH_SJLJ_SETUP_DISPATCH, dl, MVT::Other, + Op.getOperand(0)); +} + SDValue ARMTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG, const ARMSubtarget *Subtarget) const { @@ -6573,6 +6581,7 @@ SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const { case ISD::GLOBAL_OFFSET_TABLE: return LowerGLOBAL_OFFSET_TABLE(Op, DAG); case ISD::EH_SJLJ_SETJMP: return LowerEH_SJLJ_SETJMP(Op, DAG); case ISD::EH_SJLJ_LONGJMP: return LowerEH_SJLJ_LONGJMP(Op, DAG); + case ISD::EH_SJLJ_SETUP_DISPATCH: return LowerEH_SJLJ_SETUP_DISPATCH(Op, DAG); case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG, Subtarget); case ISD::BITCAST: return ExpandBITCAST(Op.getNode(), DAG); @@ -7735,6 +7744,9 @@ ARMTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI, case ARM::tInt_eh_sjlj_setjmp: case ARM::t2Int_eh_sjlj_setjmp: case ARM::t2Int_eh_sjlj_setjmp_nofp: + return BB; + + case ARM::Int_eh_sjlj_setup_dispatch: EmitSjLjDispatchBlock(MI, BB); return BB; diff --git a/llvm/lib/Target/ARM/ARMISelLowering.h b/llvm/lib/Target/ARM/ARMISelLowering.h index efc9020..9d66be0 100644 --- a/llvm/lib/Target/ARM/ARMISelLowering.h +++ b/llvm/lib/Target/ARM/ARMISelLowering.h @@ -79,6 +79,7 @@ namespace llvm { EH_SJLJ_SETJMP, // SjLj exception handling setjmp. EH_SJLJ_LONGJMP, // SjLj exception handling longjmp. + EH_SJLJ_SETUP_DISPATCH, // SjLj exception handling setup_dispatch. TC_RETURN, // Tail call return pseudo. @@ -496,6 +497,7 @@ namespace llvm { ISD::ArgFlagsTy Flags) const; SDValue LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const; SDValue LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const; + SDValue LowerEH_SJLJ_SETUP_DISPATCH(SDValue Op, SelectionDAG &DAG) const; SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG, const ARMSubtarget *Subtarget) const; SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const; diff --git a/llvm/lib/Target/ARM/ARMInstrInfo.td b/llvm/lib/Target/ARM/ARMInstrInfo.td index 61c45af..ded5533 100644 --- a/llvm/lib/Target/ARM/ARMInstrInfo.td +++ b/llvm/lib/Target/ARM/ARMInstrInfo.td @@ -59,6 +59,7 @@ def SDT_ARMThreadPointer : SDTypeProfile<1, 0, [SDTCisPtrTy<0>]>; def SDT_ARMEH_SJLJ_Setjmp : SDTypeProfile<1, 2, [SDTCisInt<0>, SDTCisPtrTy<1>, SDTCisInt<2>]>; def SDT_ARMEH_SJLJ_Longjmp: SDTypeProfile<0, 2, [SDTCisPtrTy<0>, SDTCisInt<1>]>; +def SDT_ARMEH_SJLJ_SetupDispatch: SDTypeProfile<0, 0, []>; def SDT_ARMMEMBARRIER : SDTypeProfile<0, 1, [SDTCisInt<0>]>; @@ -163,6 +164,9 @@ def ARMeh_sjlj_setjmp: SDNode<"ARMISD::EH_SJLJ_SETJMP", def ARMeh_sjlj_longjmp: SDNode<"ARMISD::EH_SJLJ_LONGJMP", SDT_ARMEH_SJLJ_Longjmp, [SDNPHasChain, SDNPSideEffect]>; +def ARMeh_sjlj_setup_dispatch: SDNode<"ARMISD::EH_SJLJ_SETUP_DISPATCH", + SDT_ARMEH_SJLJ_SetupDispatch, + [SDNPHasChain, SDNPSideEffect]>; def ARMMemBarrierMCR : SDNode<"ARMISD::MEMBARRIER_MCR", SDT_ARMMEMBARRIER, [SDNPHasChain, SDNPSideEffect]>; @@ -5301,6 +5305,10 @@ def Int_eh_sjlj_longjmp : PseudoInst<(outs), (ins GPR:$src, GPR:$scratch), Requires<[IsARM]>; } +let isBarrier = 1, hasSideEffects = 1, usesCustomInserter = 1 in +def Int_eh_sjlj_setup_dispatch : PseudoInst<(outs), (ins), NoItinerary, + [(ARMeh_sjlj_setup_dispatch)]>; + // eh.sjlj.dispatchsetup pseudo-instruction. // This pseudo is used for both ARM and Thumb. Any differences are handled when // the pseudo is expanded (which happens before any passes that need the diff --git a/llvm/test/CodeGen/ARM/setjmp_longjmp.ll b/llvm/test/CodeGen/ARM/setjmp_longjmp.ll new file mode 100644 index 0000000..7100175 --- /dev/null +++ b/llvm/test/CodeGen/ARM/setjmp_longjmp.ll @@ -0,0 +1,113 @@ +; RUN: llc %s -o - | FileCheck %s +target triple = "armv7-apple-ios" + +declare i32 @llvm.eh.sjlj.setjmp(i8*) +declare void @llvm.eh.sjlj.longjmp(i8*) +@g = external global i32 + +declare void @may_throw() +declare i32 @__gxx_personality_sj0(...) +declare i8* @__cxa_begin_catch(i8*) +declare void @__cxa_end_catch() +declare i32 @llvm.eh.typeid.for(i8*) +declare i8* @llvm.frameaddress(i32) +declare i8* @llvm.stacksave() +@_ZTIPKc = external constant i8* + +; CHECK-LABEL: foobar +; +; setjmp sequence: +; CHECK: add [[PCREG:r[0-9]+]], pc, #8 +; CHECK-NEXT: str [[PCREG]], {{\[}}[[BUFREG:r[0-9]+]], #4] +; CHECK-NEXT: mov r0, #0 +; CHECK-NEXT: add pc, pc, #0 +; CHECK-NEXT: mov r0, #1 +; +; longjmp sequence: +; CHECK: ldr sp, [{{\s*}}[[BUFREG:r[0-9]+]], #8] +; CHECK-NEXT: ldr [[DESTREG:r[0-9]+]], {{\[}}[[BUFREG]], #4] +; CHECK-NEXT: ldr r7, {{\[}}[[BUFREG]]{{\]}} +; CHECK-NEXT: bx [[DESTREG]] +define void @foobar() { +entry: + %buf = alloca [5 x i8*], align 4 + %arraydecay = getelementptr inbounds [5 x i8*], [5 x i8*]* %buf, i32 0, i32 0 + %bufptr = bitcast i8** %arraydecay to i8* + ; Note: This is simplified, in reality you have to store the framepointer + + ; stackpointer in the buffer as well for this to be legal! + %setjmpres = call i32 @llvm.eh.sjlj.setjmp(i8* %bufptr) + %tobool = icmp ne i32 %setjmpres, 0 + br i1 %tobool, label %if.then, label %if.else + +if.then: + store volatile i32 1, i32* @g, align 4 + br label %if.end + +if.else: + store volatile i32 0, i32* @g, align 4 + call void @llvm.eh.sjlj.longjmp(i8* %bufptr) + unreachable + +if.end: + ret void +} + +; CHECK-LABEL: combine_sjlj_eh_and_setjmp_longjmp +; Check that we can mix sjlj exception handling with __builtin_setjmp +; and __builtin_longjmp. +; +; setjmp sequence: +; CHECK: add [[PCREG:r[0-9]+]], pc, #8 +; CHECK-NEXT: str [[PCREG]], {{\[}}[[BUFREG:r[0-9]+]], #4] +; CHECK-NEXT: mov r0, #0 +; CHECK-NEXT: add pc, pc, #0 +; CHECK-NEXT: mov r0, #1 +; +; longjmp sequence: +; CHECK: ldr sp, [{{\s*}}[[BUFREG:r[0-9]+]], #8] +; CHECK-NEXT: ldr [[DESTREG:r[0-9]+]], {{\[}}[[BUFREG]], #4] +; CHECK-NEXT: ldr r7, {{\[}}[[BUFREG]]{{\]}} +; CHECK-NEXT: bx [[DESTREG]] +define void @combine_sjlj_eh_and_setjmp_longjmp() personality i8* bitcast (i32 (...)* @__gxx_personality_sj0 to i8*) { +entry: + %buf = alloca [5 x i8*], align 4 + invoke void @may_throw() to label %try.cont unwind label %lpad + +lpad: + %0 = landingpad { i8*, i32 } catch i8* bitcast (i8** @_ZTIPKc to i8*) + %1 = extractvalue { i8*, i32 } %0, 1 + %2 = tail call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIPKc to i8*)) #3 + %matches = icmp eq i32 %1, %2 + br i1 %matches, label %catch, label %eh.resume + +catch: + %3 = extractvalue { i8*, i32 } %0, 0 + %4 = tail call i8* @__cxa_begin_catch(i8* %3) #3 + store volatile i32 0, i32* @g, align 4 + %5 = bitcast [5 x i8*]* %buf to i8* + %arraydecay = getelementptr inbounds [5 x i8*], [5 x i8*]* %buf, i64 0, i64 0 + %6 = tail call i8* @llvm.frameaddress(i32 0) + store i8* %6, i8** %arraydecay, align 16 + %7 = tail call i8* @llvm.stacksave() + %8 = getelementptr [5 x i8*], [5 x i8*]* %buf, i64 0, i64 2 + store i8* %7, i8** %8, align 16 + %9 = call i32 @llvm.eh.sjlj.setjmp(i8* %5) + %tobool = icmp eq i32 %9, 0 + br i1 %tobool, label %if.else, label %if.then + +if.then: + store volatile i32 2, i32* @g, align 4 + call void @__cxa_end_catch() #3 + br label %try.cont + +if.else: + store volatile i32 1, i32* @g, align 4 + call void @llvm.eh.sjlj.longjmp(i8* %5) + unreachable + +eh.resume: + resume { i8*, i32 } %0 + +try.cont: + ret void +} -- 2.7.4