From c3f6054a2c781863eb6ed86ffe78646d4df5653b Mon Sep 17 00:00:00 2001 From: NAKAMURA Takumi Date: Thu, 1 Oct 2015 17:00:56 +0000 Subject: [PATCH] Revert r248959, "[WinEH] Emit int3 after noreturn calls on Win64" It broke; LLVM :: CodeGen__Generic__2009-11-16-BadKillsCrash.ll git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249032 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Target/TargetOptions.h | 6 +- lib/CodeGen/SelectionDAG/FastISel.cpp | 6 +- .../SelectionDAG/SelectionDAGBuilder.cpp | 5 +- lib/Target/X86/X86ISelLowering.cpp | 23 ---- lib/Target/X86/X86TargetMachine.cpp | 7 ++ test/CodeGen/X86/br-fold.ll | 4 +- test/CodeGen/X86/win-catchpad-rethrow.ll | 103 ------------------ test/CodeGen/X86/win64_call_epi.ll | 4 +- 8 files changed, 24 insertions(+), 134 deletions(-) delete mode 100644 test/CodeGen/X86/win-catchpad-rethrow.ll diff --git a/include/llvm/Target/TargetOptions.h b/include/llvm/Target/TargetOptions.h index e931ec875c0..bd696f399d5 100644 --- a/include/llvm/Target/TargetOptions.h +++ b/include/llvm/Target/TargetOptions.h @@ -71,7 +71,7 @@ namespace llvm { EnableFastISel(false), PositionIndependentExecutable(false), UseInitArray(false), DisableIntegratedAS(false), CompressDebugSections(false), FunctionSections(false), - DataSections(false), UniqueSectionNames(true), + DataSections(false), UniqueSectionNames(true), TrapUnreachable(false), EmulatedTLS(false), FloatABIType(FloatABI::Default), AllowFPOpFusion(FPOpFusion::Standard), Reciprocals(TargetRecip()), JTType(JumpTable::Single), @@ -169,6 +169,9 @@ namespace llvm { unsigned UniqueSectionNames : 1; + /// Emit target-specific trap instruction for 'unreachable' IR instructions. + unsigned TrapUnreachable : 1; + /// EmulatedTLS - This flag enables emulated TLS model, using emutls /// function in the runtime library.. unsigned EmulatedTLS : 1; @@ -231,6 +234,7 @@ inline bool operator==(const TargetOptions &LHS, ARE_EQUAL(EnableFastISel) && ARE_EQUAL(PositionIndependentExecutable) && ARE_EQUAL(UseInitArray) && + ARE_EQUAL(TrapUnreachable) && ARE_EQUAL(EmulatedTLS) && ARE_EQUAL(FloatABIType) && ARE_EQUAL(AllowFPOpFusion) && diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp index f97edb4ef09..13b097cfc60 100644 --- a/lib/CodeGen/SelectionDAG/FastISel.cpp +++ b/lib/CodeGen/SelectionDAG/FastISel.cpp @@ -1569,8 +1569,10 @@ bool FastISel::selectOperator(const User *I, unsigned Opcode) { } case Instruction::Unreachable: - // Nothing to emit. - return true; + if (TM.Options.TrapUnreachable) + return fastEmit_(MVT::Other, MVT::Other, ISD::TRAP) != 0; + else + return true; case Instruction::Alloca: // FunctionLowering has the static-sized case covered. diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index a48de572113..72af2760bb7 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -2205,7 +2205,10 @@ void SelectionDAGBuilder::visitIndirectBr(const IndirectBrInst &I) { getValue(I.getAddress()))); } -void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {} +void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) { + if (DAG.getTarget().Options.TrapUnreachable) + DAG.setRoot(DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, DAG.getRoot())); +} void SelectionDAGBuilder::visitFSub(const User &I) { // -0.0 - X --> fneg diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 6d8aa4a10d3..71ff9be6cda 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -2945,20 +2945,6 @@ static SDValue getMOVL(SelectionDAG &DAG, SDLoc dl, EVT VT, SDValue V1, return DAG.getVectorShuffle(VT, dl, V1, V2, &Mask[0]); } -/// Check if the fall through instruction after a call site is unreachable. -/// FIXME: This will fail if there are interesting non-code generating IR -/// instructions between the call and the unreachable (lifetime.end). In -/// practice, this should be rare because optimizations like to delete non-call -/// code before unreachable. -static bool isCallFollowedByUnreachable(ImmutableCallSite CS) { - const Instruction *NextInst; - if (auto *II = dyn_cast(CS.getInstruction())) - NextInst = II->getNormalDest()->getFirstNonPHIOrDbg(); - else - NextInst = CS.getInstruction()->getNextNode(); - return isa(NextInst); -} - SDValue X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI, SmallVectorImpl &InVals) const { @@ -3464,15 +3450,6 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI, InFlag = Chain.getValue(1); } - if (Subtarget->isTargetWin64() && CLI.CS) { - // Look for a call followed by unreachable. On Win64, we need to ensure that - // the call does not accidentally fall through to something that looks like - // an epilogue. We do this by inserting a DEBUGTRAP, which lowers to int3, - // which is what MSVC emits after noreturn calls. - if (isCallFollowedByUnreachable(*CLI.CS)) - Chain = DAG.getNode(ISD::DEBUGTRAP, dl, MVT::Other, Chain); - } - // Handle result values, copying them out of physregs into vregs that we // return. return LowerCallResult(Chain, InFlag, CallConv, isVarArg, diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp index d318244e0f7..2e869eb7c3c 100644 --- a/lib/Target/X86/X86TargetMachine.cpp +++ b/lib/Target/X86/X86TargetMachine.cpp @@ -110,6 +110,13 @@ X86TargetMachine::X86TargetMachine(const Target &T, const Triple &TT, OL), TLOF(createTLOF(getTargetTriple())), Subtarget(TT, CPU, FS, *this, Options.StackAlignmentOverride) { + // Windows stack unwinder gets confused when execution flow "falls through" + // after a call to 'noreturn' function. + // To prevent that, we emit a trap for 'unreachable' IR instructions. + // (which on X86, happens to be the 'ud2' instruction) + if (Subtarget.isTargetWin64()) + this->Options.TrapUnreachable = true; + // By default (and when -ffast-math is on), enable estimate codegen for // everything except scalar division. By default, use 1 refinement step for // all operations. Defaults may be overridden by using command-line options. diff --git a/test/CodeGen/X86/br-fold.ll b/test/CodeGen/X86/br-fold.ll index 9a7552ddad8..fd1e73bde8c 100644 --- a/test/CodeGen/X86/br-fold.ll +++ b/test/CodeGen/X86/br-fold.ll @@ -10,10 +10,10 @@ ; X64_LINUX-NEXT: %bb8.i329 ; X64_WINDOWS: orq %rax, %rcx -; X64_WINDOWS-NEXT: %bb8.i329 +; X64_WINDOWS-NEXT: ud2 ; X64_WINDOWS_GNU: orq %rax, %rcx -; X64_WINDOWS_GNU-NEXT: %bb8.i329 +; X64_WINDOWS_GNU-NEXT: ud2 @_ZN11xercesc_2_513SchemaSymbols21fgURI_SCHEMAFORSCHEMAE = external constant [33 x i16], align 32 ; <[33 x i16]*> [#uses=1] @_ZN11xercesc_2_56XMLUni16fgNotationStringE = external constant [9 x i16], align 16 ; <[9 x i16]*> [#uses=1] diff --git a/test/CodeGen/X86/win-catchpad-rethrow.ll b/test/CodeGen/X86/win-catchpad-rethrow.ll deleted file mode 100644 index 7585b079469..00000000000 --- a/test/CodeGen/X86/win-catchpad-rethrow.ll +++ /dev/null @@ -1,103 +0,0 @@ -; RUN: llc -mtriple=x86_64-pc-windows-msvc < %s | FileCheck %s - -; C++ EH rethrows are interesting, because they are calls to noreturn -; functions. There *must* be some code after the call instruction that doesn't -; look like an epilogue. We use int3 to be consistent with MSVC. - -; Based on this C++ source: -; int main() { -; try { -; throw 42; -; } catch (int) { -; try { -; throw; -; } catch (int) { -; } -; } -; return 0; -; } - -; ModuleID = 't.cpp' -target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128" -target triple = "x86_64-pc-windows-msvc" - -%rtti.TypeDescriptor2 = type { i8**, i8*, [3 x i8] } -%eh.CatchableType = type { i32, i32, i32, i32, i32, i32, i32 } -%eh.CatchableTypeArray.1 = type { i32, [1 x i32] } -%eh.ThrowInfo = type { i32, i32, i32, i32 } - -$"\01??_R0H@8" = comdat any - -$"_CT??_R0H@84" = comdat any - -$_CTA1H = comdat any - -$_TI1H = comdat any - -@"\01??_7type_info@@6B@" = external constant i8* -@"\01??_R0H@8" = linkonce_odr global %rtti.TypeDescriptor2 { i8** @"\01??_7type_info@@6B@", i8* null, [3 x i8] c".H\00" }, comdat -@__ImageBase = external constant i8 -@"_CT??_R0H@84" = linkonce_odr unnamed_addr constant %eh.CatchableType { i32 1, i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%rtti.TypeDescriptor2* @"\01??_R0H@8" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32), i32 0, i32 -1, i32 0, i32 4, i32 0 }, section ".xdata", comdat -@_CTA1H = linkonce_odr unnamed_addr constant %eh.CatchableTypeArray.1 { i32 1, [1 x i32] [i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%eh.CatchableType* @"_CT??_R0H@84" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32)] }, section ".xdata", comdat -@_TI1H = linkonce_odr unnamed_addr constant %eh.ThrowInfo { i32 0, i32 0, i32 0, i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%eh.CatchableTypeArray.1* @_CTA1H to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32) }, section ".xdata", comdat - -define i32 @main() #0 personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*) { -entry: - %tmp = alloca i32, align 4 - store i32 42, i32* %tmp, align 4 - %0 = bitcast i32* %tmp to i8* - invoke void @_CxxThrowException(i8* %0, %eh.ThrowInfo* nonnull @_TI1H) #1 - to label %unreachable unwind label %catch.dispatch - -catch.dispatch: ; preds = %entry - %1 = catchpad [%rtti.TypeDescriptor2* @"\01??_R0H@8", i32 0, i8* null] - to label %catch unwind label %catchendblock - -catch: ; preds = %catch.dispatch - invoke void @_CxxThrowException(i8* null, %eh.ThrowInfo* null) #1 - to label %unreachable unwind label %catch.dispatch.1 - -catch.dispatch.1: ; preds = %catch - %2 = catchpad [%rtti.TypeDescriptor2* @"\01??_R0H@8", i32 0, i8* null] - to label %catch.3 unwind label %catchendblock.2 - -catch.3: ; preds = %catch.dispatch.1 - catchret %2 to label %try.cont - -try.cont: ; preds = %catch.3 - catchret %1 to label %try.cont.5 - -try.cont.5: ; preds = %try.cont - ret i32 0 - -catchendblock.2: ; preds = %catch.dispatch.1 - catchendpad unwind label %catchendblock - -catchendblock: ; preds = %catchendblock.2, %catch.dispatch - catchendpad unwind to caller - -unreachable: ; preds = %catch, %entry - unreachable -} - -declare void @_CxxThrowException(i8*, %eh.ThrowInfo*) - -declare i32 @__CxxFrameHandler3(...) - -attributes #0 = { "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-features"="+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" } -attributes #1 = { noreturn } - -; CHECK: main: -; CHECK: .seh_proc main -; CHECK: movl $42, -; CHECK-DAG: leaq {{.*}}, %rcx -; CHECK-DAG: leaq _TI1H(%rip), %rdx -; CHECK: callq _CxxThrowException -; CHECK-NEXT: int3 - -; CHECK: "?catch$1@?0?main@4HA": -; CHECK: .seh_proc "?catch$1@?0?main@4HA" -; CHECK-DAG: xorl %ecx, %ecx -; CHECK-DAG: xorl %edx, %edx -; CHECK: callq _CxxThrowException -; CHECK-NEXT: int3 diff --git a/test/CodeGen/X86/win64_call_epi.ll b/test/CodeGen/X86/win64_call_epi.ll index d514032dcbf..096cbe41c54 100644 --- a/test/CodeGen/X86/win64_call_epi.ll +++ b/test/CodeGen/X86/win64_call_epi.ll @@ -24,9 +24,9 @@ catch: ; WIN64: nop ; WIN64: addq ${{[0-9]+}}, %rsp ; WIN64: retq -; Check for 'int3' after noreturn call +; Check for 'ud2' after noreturn call ; WIN64: callq _Unwind_Resume -; WIN64-NEXT: int3 +; WIN64-NEXT: ud2 ; WIN64: .seh_endproc -- 2.34.1