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[WinEH] Fix stack alignment in funclets and ParentFrameOffset calculation 

Our previous value of "16 + 8 + MaxCallFrameSize" for ParentFrameOffset
is incorrect when CSRs are involved. We were supposed to have a test
case to catch this, but it wasn't very rigorous.

The main effect here is that calling _CxxThrowException inside a
catchpad doesn't immediately crash on MOVAPS when you have an odd number
of CSRs.

llvm-svn: 250583
This commit is contained in:
Reid Kleckner 2015-10-16 23:43:27 +00:00
parent 02b74368ce
commit 28e490342b
5 changed files with 182 additions and 12 deletions
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4
llvm/include/llvm/Target/TargetFrameLowering.h
View File

@ -265,6 +265,10 @@ public:
RegScavenger *RS = nullptr) const {
}
virtual unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const {
report_fatal_error("WinEH not implemented for this target");
}
/// eliminateCallFramePseudoInstr - This method is called during prolog/epilog
/// code insertion to eliminate call frame setup and destroy pseudo
/// instructions (but only if the Target is using them). It is responsible

14
llvm/lib/CodeGen/AsmPrinter/WinException.cpp
View File

@ -710,6 +710,13 @@ void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
OS.EmitValue(create32bitRef(HandlerMapXData), 4); // HandlerArray
}
// All funclets use the same parent frame offset currently.
unsigned ParentFrameOffset = 0;
if (shouldEmitPersonality) {
const TargetFrameLowering *TFI = MF->getSubtarget().getFrameLowering();
ParentFrameOffset = TFI->getWinEHParentFrameOffset(*MF);
}
for (size_t I = 0, E = FuncInfo.TryBlockMap.size(); I != E; ++I) {
WinEHTryBlockMapEntry &TBME = FuncInfo.TryBlockMap[I];
MCSymbol *HandlerMapXData = HandlerMaps[I];
@ -749,16 +756,11 @@ void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
OS.EmitValue(create32bitRef(HT.TypeDescriptor), 4); // Type
OS.EmitValue(FrameAllocOffsetRef, 4); // CatchObjOffset
OS.EmitValue(create32bitRef(HandlerSym), 4); // Handler
if (shouldEmitPersonality) {
// Keep this in sync with X86FrameLowering::emitPrologue.
int ParentFrameOffset =
16 + 8 + MF->getFrameInfo()->getMaxCallFrameSize();
if (shouldEmitPersonality)
OS.EmitIntValue(ParentFrameOffset, 4); // ParentFrameOffset
}
}
}
}
// IPToStateMapEntry {
// void *IP;

34
llvm/lib/Target/X86/X86FrameLowering.cpp
View File

@ -786,7 +786,7 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF,
// NumBytes value that we would've used for the parent frame.
unsigned ParentFrameNumBytes = NumBytes;
if (IsFunclet)
NumBytes = MFI->getMaxCallFrameSize();
NumBytes = getWinEHFuncletFrameSize(MF);
// Skip the callee-saved push instructions.
bool PushedRegs = false;
@ -1039,6 +1039,22 @@ static bool isFuncletReturnInstr(MachineInstr *MI) {
llvm_unreachable("impossible");
}
unsigned X86FrameLowering::getWinEHFuncletFrameSize(const MachineFunction &MF) const {
// This is the size of the pushed CSRs.
unsigned CSSize =
MF.getInfo<X86MachineFunctionInfo>()->getCalleeSavedFrameSize();
// This is the amount of stack a funclet needs to allocate.
unsigned MaxCallSize = MF.getFrameInfo()->getMaxCallFrameSize();
// RBP is not included in the callee saved register block. After pushing RBP,
// everything is 16 byte aligned. Everything we allocate before an outgoing
// call must also be 16 byte aligned.
unsigned FrameSizeMinusRBP =
RoundUpToAlignment(CSSize + MaxCallSize, getStackAlignment());
// Subtract out the size of the callee saved registers. This is how much stack
// each funclet will allocate.
return FrameSizeMinusRBP - CSSize;
}
void X86FrameLowering::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
@ -1067,7 +1083,7 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
uint64_t NumBytes = 0;
if (MBBI->getOpcode() == X86::CATCHRET) {
NumBytes = MFI->getMaxCallFrameSize();
NumBytes = getWinEHFuncletFrameSize(MF);
assert(hasFP(MF) && "EH funclets without FP not yet implemented");
MachineBasicBlock *TargetMBB = MBBI->getOperand(0).getMBB();
@ -1107,7 +1123,7 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
.addMBB(TargetMBB);
}
} else if (MBBI->getOpcode() == X86::CLEANUPRET) {
NumBytes = MFI->getMaxCallFrameSize();
NumBytes = getWinEHFuncletFrameSize(MF);
assert(hasFP(MF) && "EH funclets without FP not yet implemented");
BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::POP64r : X86::POP32r),
MachineFramePtr)
@ -2211,3 +2227,15 @@ MachineBasicBlock::iterator X86FrameLowering::restoreWin32EHStackPointers(
}
return MBBI;
}
unsigned X86FrameLowering::getWinEHParentFrameOffset(const MachineFunction &MF) const {
// RDX, the parent frame pointer, is homed into 16(%rsp) in the prologue.
unsigned Offset = 16;
// RBP is immediately pushed.
Offset += SlotSize;
// All callee-saved registers are then pushed.
Offset += MF.getInfo<X86MachineFunctionInfo>()->getCalleeSavedFrameSize();
// Every funclet allocates enough stack space for the largest outgoing call.
Offset += getWinEHFuncletFrameSize(MF);
return Offset;
}

4
llvm/lib/Target/X86/X86FrameLowering.h
View File

@ -101,6 +101,8 @@ public:
MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const override;
unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const override;
/// Check the instruction before/after the passed instruction. If
/// it is an ADD/SUB/LEA instruction it is deleted argument and the
/// stack adjustment is returned as a positive value for ADD/LEA and
@ -152,6 +154,8 @@ private:
restoreWin32EHStackPointers(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI, DebugLoc DL,
bool RestoreSP = false) const;
unsigned getWinEHFuncletFrameSize(const MachineFunction &MF) const;
};
} // End llvm namespace

138
llvm/test/CodeGen/X86/win-catchpad-csrs.ll
View File

@ -125,14 +125,20 @@ catchendblock: ; preds = %catch,
; X64: .seh_pushreg 5
; X64: pushq %rsi
; X64: .seh_pushreg 6
; X64: subq $32, %rsp
; X64: .seh_stackalloc 32
; X64: pushq %rdi
; X64: .seh_pushreg 7
; X64: pushq %rbx
; X64: .seh_pushreg 3
; X64: subq $40, %rsp
; X64: .seh_stackalloc 40
; X64: leaq 32(%rdx), %rbp
; X64: .seh_endprologue
; X64: movl $2, %ecx
; X64: callq f
; X64: leaq [[contbb]](%rip), %rax
; X64: addq $32, %rsp
; X64: addq $40, %rsp
; X64: popq %rbx
; X64: popq %rdi
; X64: popq %rsi
; X64: popq %rbp
; X64: retq
@ -142,4 +148,130 @@ catchendblock: ; preds = %catch,
; X64: .long "??_R0H@8"@IMGREL
; X64: .long 0
; X64: .long "?catch$[[catch1bb]]@?0?try_catch_catch@4HA"@IMGREL
; X64: .long 88
define i32 @try_one_csr() personality i32 (...)* @__CxxFrameHandler3 {
entry:
%a = call i32 @getint()
%b = call i32 @getint()
call void (...) @useints(i32 %a)
invoke void @f(i32 1)
to label %try.cont unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchpad [%rtti.TypeDescriptor2* @"\01??_R0H@8", i32 0, i8* null]
to label %catch unwind label %catchendblock
catch:
catchret %0 to label %try.cont
try.cont: ; preds = %entry, %invoke.cont.2, %invoke.cont.3
ret i32 0
catchendblock: ; preds = %catch,
catchendpad unwind to caller
}
; X64-LABEL: try_one_csr:
; X64: pushq %rbp
; X64: .seh_pushreg 5
; X64: pushq %rsi
; X64: .seh_pushreg 6
; X64-NOT: pushq
; X64: subq $40, %rsp
; X64: .seh_stackalloc 40
; X64: leaq 32(%rsp), %rbp
; X64: .seh_setframe 5, 32
; X64: .seh_endprologue
; X64: callq getint
; X64: callq getint
; X64: callq useints
; X64: movl $1, %ecx
; X64: callq f
; X64: [[contbb:\.LBB1_[0-9]+]]: # %try.cont
; X64: addq $40, %rsp
; X64-NOT: popq
; X64: popq %rsi
; X64: popq %rbp
; X64: retq
; X64: "?catch$[[catch1bb:[0-9]+]]@?0?try_one_csr@4HA":
; X64: LBB1_[[catch1bb]]: # %catch.dispatch{{$}}
; X64: movq %rdx, 16(%rsp)
; X64: pushq %rbp
; X64: .seh_pushreg 5
; X64: pushq %rsi
; X64: .seh_pushreg 6
; X64: subq $40, %rsp
; X64: .seh_stackalloc 40
; X64: leaq 32(%rdx), %rbp
; X64: .seh_endprologue
; X64: leaq [[contbb]](%rip), %rax
; X64: addq $40, %rsp
; X64: popq %rsi
; X64: popq %rbp
; X64: retq
; X64: $handlerMap$0$try_one_csr:
; X64: .long 0
; X64: .long "??_R0H@8"@IMGREL
; X64: .long 0
; X64: .long "?catch$[[catch1bb]]@?0?try_one_csr@4HA"@IMGREL
; X64: .long 72
define i32 @try_no_csr() personality i32 (...)* @__CxxFrameHandler3 {
entry:
invoke void @f(i32 1)
to label %try.cont unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchpad [%rtti.TypeDescriptor2* @"\01??_R0H@8", i32 0, i8* null]
to label %catch unwind label %catchendblock
catch:
catchret %0 to label %try.cont
try.cont: ; preds = %entry, %invoke.cont.2, %invoke.cont.3
ret i32 0
catchendblock: ; preds = %catch,
catchendpad unwind to caller
}
; X64-LABEL: try_no_csr:
; X64: pushq %rbp
; X64: .seh_pushreg 5
; X64-NOT: pushq
; X64: subq $48, %rsp
; X64: .seh_stackalloc 48
; X64: leaq 48(%rsp), %rbp
; X64: .seh_setframe 5, 48
; X64: .seh_endprologue
; X64: movl $1, %ecx
; X64: callq f
; X64: [[contbb:\.LBB2_[0-9]+]]: # %try.cont
; X64: addq $48, %rsp
; X64-NOT: popq
; X64: popq %rbp
; X64: retq
; X64: "?catch$[[catch1bb:[0-9]+]]@?0?try_no_csr@4HA":
; X64: LBB2_[[catch1bb]]: # %catch.dispatch{{$}}
; X64: movq %rdx, 16(%rsp)
; X64: pushq %rbp
; X64: .seh_pushreg 5
; X64: subq $32, %rsp
; X64: .seh_stackalloc 32
; X64: leaq 48(%rdx), %rbp
; X64: .seh_endprologue
; X64: leaq [[contbb]](%rip), %rax
; X64: addq $32, %rsp
; X64: popq %rbp
; X64: retq
; X64: $handlerMap$0$try_no_csr:
; X64: .long 0
; X64: .long "??_R0H@8"@IMGREL
; X64: .long 0
; X64: .long "?catch$[[catch1bb]]@?0?try_no_csr@4HA"@IMGREL
; X64: .long 56