[CodeGen] Enable Windows exception handling for basic block sections

[TaoPan]

Summary

Windows x64 exception handling is quite different with Exception
Handling of Itanium C++ ABI for IA-64, no need to do EH pad operation.

Reference:
https://docs.microsoft.com/en-us/cpp/build/exception-handling-x64?view=msvc-160
https://github.com/itanium-cxx-abi/cxx-abi/blob/master/exceptions.pdf

[TaoPan]

git rebase

[TaoPan]

Remove content of parent D99487 for applying this patch

[TaoPan]

Remove content of parent D99487 for applying this patch

[TaoPan]

git rebase

[modimo]

Is there currently a difference in the output when built with -basic-block-sections=all -unique-basic-block-section-names vs. without? If so, should CHECK for both cases to highlight the difference and add some explanatory comments on why a particular transformation took place. What are considered landing pads for avoidZeroOffsetLandingPad under MSVC? I can double-check to make sure they're truly not needed.

Otherwise this looks good and works well as a first step.

[TaoPan]

In D100735#2832069, @modimo wrote:

Is there currently a difference in the output when built with -basic-block-sections=all -unique-basic-block-section-names vs. without? If so, should CHECK for both cases to highlight the difference and add some explanatory comments on why a particular transformation took place. What are considered landing pads for avoidZeroOffsetLandingPad under MSVC? I can double-check to make sure they're truly not needed.

Otherwise this looks good and works well as a first step.

Thanks for your comment!
No big difference. There are 12 more sections in Sections table, I checked asm file, there are 12 BB sections, so all added sections are BB sections. And as the test file CHECK, one relocation of .xdata section changed from ".text" to "?TestCPPEX@@YAXH@Z.__part.3". Is this difference need to add without -basic-block-sections=all -unique-basic-block-section-names case for highlight the difference?
FYI, about avoidZeroOffsetLandingPad under MSVC, isFuncletEHPersonality(Pers) check and return of SelectionDAGISel::PrepareEHLandingPad() prevent later addLandingPad(MBB) and adding TargetOpcode::EH_LABEL MachineInstr in the case of MSVC. while (!MI->isEHLabel()) ++MI; of avoidZeroOffsetLandingPad is dead loop as no EHLabel MI in the case of MSVC.

[modimo]

In D100735#2832513, @TaoPan wrote:

No big difference. There are 12 more sections in Sections table, I checked asm file, there are 12 BB sections, so all added sections are BB sections. And as the test file CHECK, one relocation of .xdata section changed from ".text" to "?TestCPPEX@@YAXH@Z.__part.3". Is this difference need to add without -basic-block-sections=all -unique-basic-block-section-names case for highlight the difference?

Yeah, check that the .xdata relocation changed and the size of the Sections table (CHECK-COUNT or looking at the last entry for each configuration). Also does the above test case run correctly when built with Clang if you define it as "main" and add something interesting to the __except clause (with and without BBS)?

FYI, about avoidZeroOffsetLandingPad under MSVC, isFuncletEHPersonality(Pers) check and return of SelectionDAGISel::PrepareEHLandingPad() prevent later addLandingPad(MBB) and adding TargetOpcode::EH_LABEL MachineInstr in the case of MSVC. while (!MI->isEHLabel()) ++MI; of avoidZeroOffsetLandingPad is dead loop as no EHLabel MI in the case of MSVC.

I'm not sure what you mean by dead loop for while (!MI->isEHLabel()) Can you elaborate?

[TaoPan]

Add baseline case and check size of the Sections table

[TaoPan]

In D100735#2834985, @modimo wrote:

In D100735#2832513, @TaoPan wrote:

No big difference. There are 12 more sections in Sections table, I checked asm file, there are 12 BB sections, so all added sections are BB sections. And as the test file CHECK, one relocation of .xdata section changed from ".text" to "?TestCPPEX@@YAXH@Z.__part.3". Is this difference need to add without -basic-block-sections=all -unique-basic-block-section-names case for highlight the difference?

Yeah, check that the .xdata relocation changed and the size of the Sections table (CHECK-COUNT or looking at the last entry for each configuration). Also does the above test case run correctly when built with Clang if you define it as "main" and add something interesting to the __except clause (with and without BBS)?

I added baseline (without BBS) case and check the size of the Sections table.
I tried to build with clang, define it as "main" and add printf to the __except clause

without BBS, the exception can be captured, printf log in __except clause was printed.
with BBS,  build fail with "error: Cannot represent this expression", I'm investigating this error.

FYI, about avoidZeroOffsetLandingPad under MSVC, isFuncletEHPersonality(Pers) check and return of SelectionDAGISel::PrepareEHLandingPad() prevent later addLandingPad(MBB) and adding TargetOpcode::EH_LABEL MachineInstr in the case of MSVC. while (!MI->isEHLabel()) ++MI; of avoidZeroOffsetLandingPad is dead loop as no EHLabel MI in the case of MSVC.

I'm not sure what you mean by dead loop for while (!MI->isEHLabel()) Can you elaborate?

The dead loop occurs if "MBB->setIsEHPad() but all MIs of the MBB are not isEHLabel()", as condition !MI->isEHLabel() of while loop is always true.
Adding "&& MI != MBB.end()" to while (!MI->isEHLabel()) will resolve this dead loop.
The iterator is rolling loop, begin() is next to end(), the '++' operation change the iterator in loop turn, e.g. if size() is 2, the turn of '++' operation is:

begin() (1st node) -> 2nd node -> end() -> begin() (1st node) -> 2nd node -> ....

I don't know the reason MBB->setIsEHPad() without any MI of the MBB setIsEHLabel() in the case of Windows COFF.

[modimo]

In D100735#2838154, @TaoPan wrote:

I added baseline (without BBS) case and check the size of the Sections table.

Nice thanks. One comment on the format.

I tried to build with clang, define it as "main" and add printf to the __except clause

without BBS, the exception can be captured, printf log in __except clause was printed.
with BBS,  build fail with "error: Cannot represent this expression", I'm investigating this error.

Cool, feel free to file a bug and link it here to track progress.

The iterator is rolling loop, begin() is next to end(), the '++' operation change the iterator in loop turn, e.g. if size() is 2, the turn of '++' operation is:

begin() (1st node) -> 2nd node -> end() -> begin() (1st node) -> 2nd node -> ....

Ah it becomes infinite, thanks for clarifying.

I don't know the reason MBB->setIsEHPad() without any MI of the MBB setIsEHLabel() in the case of Windows COFF.

My cursory understanding is that Windows COFF in LLVM uses a different set of intrinsics to represent EH which probably don't fall under EHLabel. There's probably a good reason for that. If this is the case then probably better to guard it like you're currently doing from scanning wastefully. I would guard with if (!<triple for windows>) rather specifically checking for ELF. Also, put the check inside avoidZeroOffsetLandingPad rather than the call to it so the call site doesn't have to be aware of this.

llvm/test/MC/COFF/seh-bbs.ll

89

I would interleave these with the baseline so its easy to see how exactly the codegen differs, for this example:

FileCheck --check-prefix=COMMON,BASELINE %s
FileCheck --check-prefix=COMMON,BBS %s
...
; COMMON:          Relocations [
; COMMON-NEXT:       0xC IMAGE_REL_AMD64_ADDR32NB __C_specific_handler
; COMMON-NEXT:       0x14 IMAGE_REL_AMD64_ADDR32NB .text
; COMMON-NEXT:       0x18 IMAGE_REL_AMD64_ADDR32NB .text
; BASELINE:       0x20 IMAGE_REL_AMD64_ADDR32NB .text
; BBS:            0x20 IMAGE_REL_AMD64_ADDR32NB ?TestCPPEX@@YAXH@Z.__part.3

It's also good to add short comments for these diff spots on why this is expected behavior.

[TaoPan]

Change CHECK format of test to COMMON, BASELINE, BBS for highlighting difference of BASELINE and BBS.
Change triple condition from COFF to Windows.
Move check of Windows inside avoidZeroOffsetLandingPad.
Add iterator end check for avoiding infinite loop.

[TaoPan]

Add comment for difference of section number of BASELINE and BBS

[TaoPan]

In D100735#2842162, @modimo wrote:

In D100735#2838154, @TaoPan wrote:

I tried to build with clang, define it as "main" and add printf to the __except clause

without BBS, the exception can be captured, printf log in __except clause was printed.
with BBS,  build fail with "error: Cannot represent this expression", I'm investigating this error.

Cool, feel free to file a bug and link it here to track progress.

This bug depends on #D99487 and this commit, can't be reproduced without these two commits. Is it ok file the bug after landing these two commits?

I don't know the reason MBB->setIsEHPad() without any MI of the MBB setIsEHLabel() in the case of Windows COFF.

My cursory understanding is that Windows COFF in LLVM uses a different set of intrinsics to represent EH which probably don't fall under EHLabel. There's probably a good reason for that. If this is the case then probably better to guard it like you're currently doing from scanning wastefully. I would guard with if (!<triple for windows>) rather specifically checking for ELF. Also, put the check inside avoidZeroOffsetLandingPad rather than the call to it so the call site doesn't have to be aware of this.

Thanks for your analysis! I changed code according to your guidance.

llvm/test/MC/COFF/seh-bbs.ll

89

Good idea! I changed check format as you guided.

[modimo]

In D100735#2843362, @TaoPan wrote:

In D100735#2842162, @modimo wrote:

Cool, feel free to file a bug and link it here to track progress.

This bug depends on #D99487 and this commit, can't be reproduced without these two commits. Is it ok file the bug after landing these two commits?

In that case it would make sense to fix this in D99487. I pulled this down locally and noticed that baseline testing with BBS hits:

llc: /home/modimo/llvm-project/llvm/lib/MC/MCStreamer.cpp:1207: virtual void llvm::MCStreamer::SwitchSection(llvm::MCSection *, const llvm::MCExpr *): Assertion Section && "Cannot switch to a null section!"' failed.`

If you plan on checking this test in early (which I would recommend) before all the other pieces are in place you can replace RUN for BBS with a TODO D99487.

llvm/test/MC/COFF/seh-bbs.ll

51

";" for comment lines

[TaoPan]

Fix comment format of test

[TaoPan]

In D100735#2845073, @modimo wrote:

In D100735#2843362, @TaoPan wrote:

In D100735#2842162, @modimo wrote:

Cool, feel free to file a bug and link it here to track progress.

This bug depends on #D99487 and this commit, can't be reproduced without these two commits. Is it ok file the bug after landing these two commits?

In that case it would make sense to fix this in D99487. I pulled this down locally and noticed that baseline testing with BBS hits:

llc: /home/modimo/llvm-project/llvm/lib/MC/MCStreamer.cpp:1207: virtual void llvm::MCStreamer::SwitchSection(llvm::MCSection *, const llvm::MCExpr *): Assertion Section && "Cannot switch to a null section!"' failed.`

If you plan on checking this test in early (which I would recommend) before all the other pieces are in place you can replace RUN for BBS with a TODO D99487.

I set D99487 as this patch's parent according to @tmsriram 's comment, it's the reason why the auto test passed but you pull only this down locally and run this test crash. The section of SwitchSection() is created by D99487.
I submitted BBS patches according to purpose:

D99487 (parent of the below two patches): BBS basic function on Windows
D100735 (this patch):  BBS exception handling on Windows
D101421: BBS DebugInfo on Windows

So the upper mentioned bug "with BBS, build fail with "error: Cannot represent this expression", I'm investigating this error" belongs to this patch.

llvm/test/MC/COFF/seh-bbs.ll

51

Thanks! I changed to ";"

[TaoPan]

Update test for reproducing build error of "<unknown>:0: error: Cannot represent this expression" and fix the error

[modimo]

In D100735#2846280, @TaoPan wrote:

D99487 (parent of the below two patches): BBS basic function on Windows
D100735 (this patch):  BBS exception handling on Windows
D101421: BBS DebugInfo on Windows

Is the plan to commit all of this at once?

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

3247

How does this change interact with the ELF beginFunclet/endFunclet?

[TaoPan]

In D100735#2860997, @modimo wrote:

In D100735#2846280, @TaoPan wrote:

D99487 (parent of the below two patches): BBS basic function on Windows
D100735 (this patch):  BBS exception handling on Windows
D101421: BBS DebugInfo on Windows

Is the plan to commit all of this at once?

Yes.
Could you please review this commit further?

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

3247

No impact.
The ELF child classes of class EHStream don't override beginFunclet/endFunclet, refer to llvm/lib/CodeGen/AsmPrinter/DwarfException.h, class DwarfCFIExceptionBase, DwarfCFIException, ARMException.
Only class WinException override beginFunclet/endFunclet of class EHStream, refer to llvm/lib/CodeGen/AsmPrinter/WinException.h, class WinException.

[TaoPan]

git rebase

[modimo]

LGTM

[TaoPan]

Thanks @modimo for big help!
Any other review comment?

[modimo]

In D100735#2872811, @TaoPan wrote:

Thanks @modimo for big help!
Any other review comment?

Not on this change no.

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
 
   PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
 }
 
 /// emitBasicBlockStart - This method prints the label for the specified
 /// MachineBasicBlock, an alignment (if present) and a comment describing
 /// it if appropriate.
 void AsmPrinter::emitBasicBlockStart(const MachineBasicBlock &MBB) {
-  // End the previous funclet and start a new one.
-  if (MBB.isEHFuncletEntry()) {
-    for (const HandlerInfo &HI : Handlers) {
+  // End the previous funclet.
+  if (MBB.isEHFuncletEntry())
+    for (const HandlerInfo &HI : Handlers)
       HI.Handler->endFunclet();
-      HI.Handler->beginFunclet(MBB);
-    }
-  }
 
   // Emit an alignment directive for this block, if needed.
   const Align Alignment = MBB.getAlignment();
   if (Alignment != Align(1))
     emitAlignment(Alignment);
 
   // Switch to a new section if this basic block must begin a section. The
   // entry block is always placed in the function section and is handled
   // separately.
   if (MBB.isBeginSection() && !MBB.isEntryBlock()) {
     OutStreamer->SwitchSection(
         getObjFileLowering().getSectionForMachineBasicBlock(MF->getFunction(),
                                                             MBB, TM));
     CurrentSectionBeginSym = MBB.getSymbol();
   }
 
+  // WinException::beginFunclet() set CurrentFuncletTextSection as
+  // Asm->OutStreamer->getCurrentSectionOnly(), start new funclet after
+  // switching to new created BB section.
+  if (MBB.isEHFuncletEntry())
+    for (const HandlerInfo &HI : Handlers)
+      HI.Handler->beginFunclet(MBB);
+
   // If the block has its address taken, emit any labels that were used to
   // reference the block.  It is possible that there is more than one label
   // here, because multiple LLVM BB's may have been RAUW'd to this block after
   // the references were generated.
   if (MBB.hasAddressTaken()) {
     const BasicBlock *BB = MBB.getBasicBlock();
     if (isVerbose())
       OutStreamer->AddComment("Block address taken");

llvm/lib/CodeGen/BasicBlockSections.cpp

void llvm::sortBasicBlocksAndUpdateBranches(
   updateBranches(MF, PreLayoutFallThroughs);
 }
 
 // If the exception section begins with a landing pad, that landing pad will
 // assume a zero offset (relative to @LPStart) in the LSDA. However, a value of
 // zero implies "no landing pad." This function inserts a NOP just before the EH
 // pad label to ensure a nonzero offset. Returns true if padding is not needed.
 static bool avoidZeroOffsetLandingPad(MachineFunction &MF) {
+  if (!MF.getTarget().getTargetTriple().isOSWindows()) {
     for (auto &MBB : MF) {
       if (MBB.isBeginSection() && MBB.isEHPad()) {
         MachineBasicBlock::iterator MI = MBB.begin();
-      while (!MI->isEHLabel())
+        while (MI != MBB.end() && !MI->isEHLabel())
           ++MI;
+        if (MI != MBB.end()) {
           MCInst Nop = MF.getSubtarget().getInstrInfo()->getNop();
           BuildMI(MBB, MI, DebugLoc(),
                   MF.getSubtarget().getInstrInfo()->get(Nop.getOpcode()));
           return false;
         }
       }
+    }
+  }
   return true;
 }
 
 // This checks if the source of this function has drifted since this binary was
 // profiled previously.  For now, we are piggy backing on what PGO does to
 // detect this with instrumented profiles.  PGO emits an hash of the IR and
 // checks if the hash has changed.  Advanced basic block layout is usually done
 // on top of PGO optimized binaries and hence this check works well in practice.

llvm/test/MC/COFF/seh-bbs.ll

+; RUN: llc -simplifycfg-require-and-preserve-domtree=1 < %s -mtriple=x86_64-windows-msvc -function-sections | llvm-mc -triple=x86_64-windows-msvc -filetype=obj - | llvm-readobj -S --sd --sr -u - | FileCheck --check-prefix=COMMON --check-prefix=BASELINE %s
+; RUN: llc -simplifycfg-require-and-preserve-domtree=1 < %s -mtriple=x86_64-windows-msvc -function-sections -basic-block-sections=all -unique-basic-block-section-names | llvm-mc -triple=x86_64-windows-msvc -filetype=obj - | llvm-readobj -S --sd --sr -u - | FileCheck --check-prefix=COMMON --check-prefix=BBS %s
+
+; COMMON:        Sections [
+; COMMON:          Section {
+; COMMON:            Name: .xdata
+; COMMON:            RawDataSize: 36
+; COMMON:            RelocationCount: 4
+; COMMON:            Characteristics [
+; COMMON-NEXT:         IMAGE_SCN_ALIGN_4BYTES
+; COMMON-NEXT:         IMAGE_SCN_CNT_INITIALIZED_DATA
+; COMMON-NEXT:         IMAGE_SCN_LNK_COMDAT
+; COMMON-NEXT:         IMAGE_SCN_MEM_READ
+; COMMON-NEXT:       ]
+; COMMON:            Relocations [
+; COMMON-NEXT:         0xC IMAGE_REL_AMD64_ADDR32NB __C_specific_handler
+; COMMON-NEXT:         0x14 IMAGE_REL_AMD64_ADDR32NB .text
+; COMMON-NEXT:         0x18 IMAGE_REL_AMD64_ADDR32NB .text
+; BASELINE:            0x20 IMAGE_REL_AMD64_ADDR32NB .text
+; BBS:                 0x20 IMAGE_REL_AMD64_ADDR32NB main.__part.2
+; COMMON:            ]
+; COMMON:            SectionData (
+; COMMON-NEXT:         0000: 190A0345 0A030572 01500000 00000000
+; BASELINE-NEXT:       0010: 01000000 12000000 34000000 01000000
+; BASELINE-NEXT:       0020: 35000000
+; BBS-NEXT:            0010: 01000000 12000000 11000000 01000000
+; BBS-NEXT:            0020: 00000000
+; COMMON-NEXT:       )
+; COMMON-NEXT:     }
+; COMMON:          Section {
+; COMMON:            Name: .pdata
+; COMMON:            RawDataSize: 12
+; COMMON:            RelocationCount: 3
+; COMMON:            Characteristics [
+; COMMON-NEXT:         IMAGE_SCN_ALIGN_4BYTES
+; COMMON-NEXT:         IMAGE_SCN_CNT_INITIALIZED_DATA
+; COMMON-NEXT:         IMAGE_SCN_LNK_COMDAT
+; COMMON-NEXT:         IMAGE_SCN_MEM_READ
+; COMMON-NEXT:       ]
+; COMMON:            Relocations [
+; COMMON-NEXT:         0x0 IMAGE_REL_AMD64_ADDR32NB main
+; COMMON-NEXT:         0x4 IMAGE_REL_AMD64_ADDR32NB main
+; COMMON-NEXT:         0x8 IMAGE_REL_AMD64_ADDR32NB .xdata
+; COMMON-NEXT:       ]
+; COMMON:            SectionData (
+; BASELINE-NEXT:       0000: 00000000 4F000000 00000000
+; BBS-NEXT:            0000: 00000000 2B000000 00000000
+; COMMON-NEXT:       )
+; COMMON-NEXT:     }
+; 15 BB Sections and 3 more .xdata and .pdata pairs for function "??0exception@std@@QEAA@QEBD@Z",
+; "??0exception@std@@QEAA@AEBV01@@Z" and "??1exception@std@@UEAA@XZ" in BBS, 21 more sections
+; in Section table of BBS
+; BASELINE:          Number: 45
+; BASELINE-NOT:      Number: 46
+; BBS:               Number: 66
+; BBS-NOT:           Number: 67
+; COMMON:        ]
+; COMMON:        UnwindInformation [
+; COMMON:          RuntimeFunction {
+; COMMON-NEXT:       StartAddress: main (0x0)
+; BASELINE-NEXT:     EndAddress: main +0x4F (0x4)
+; BBS-NEXT:          EndAddress: main +0x2B (0x4)
+; COMMON-NEXT:       UnwindInfoAddress: .xdata (0x8)
+; COMMON-NEXT:       UnwindInfo {
+; COMMON-NEXT:         Version: 1
+; COMMON-NEXT:         Flags [ (0x3)
+; COMMON-NEXT:           ExceptionHandler (0x1)
+; COMMON-NEXT:           TerminateHandler (0x2)
+; COMMON-NEXT:         ]
+; COMMON-NEXT:         PrologSize: 10
+; COMMON-NEXT:         FrameRegister: RBP (0x5)
+; COMMON-NEXT:         FrameOffset: 0x4
+; COMMON-NEXT:         UnwindCodeCount: 3
+; COMMON-NEXT:         UnwindCodes [
+; COMMON-NEXT:           0x0A: SET_FPREG reg=RBP, offset=0x40
+; COMMON-NEXT:           0x05: ALLOC_SMALL size=64
+; COMMON-NEXT:           0x01: PUSH_NONVOL reg=RBP
+; COMMON-NEXT:         ]
+; COMMON-NEXT:         Handler: __C_specific_handler (0xC)
+; COMMON-NEXT:       }
+; COMMON-NEXT:     }
+; COMMON:        ]
+
+; Generated with this C++ source:
+; #include <stdio.h>
+; #include <Windows.h>
+; #include <exception>
+;
+; int main()
+; {
+;     __try
+;     {
+;         throw std::exception("");
+;     }
+;     __except(EXCEPTION_EXECUTE_HANDLER)
+;     {
+;         printf("Executing SEH __except block\r\n");
+;     }
+;     return 0;
+; }
+
+; ModuleID = 'winseh.cpp'
+source_filename = "winseh.cpp"
+target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.29.30037"
+
+%rtti.TypeDescriptor19 = type { i8**, i8*, [20 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 }
+%rtti.CompleteObjectLocator = type { i32, i32, i32, i32, i32, i32 }
+%rtti.ClassHierarchyDescriptor = type { i32, i32, i32, i32 }
+%rtti.BaseClassDescriptor = type { i32, i32, i32, i32, i32, i32, i32 }
+%"class.std::exception" = type { i32 (...)**, %struct.__std_exception_data }
+%struct.__std_exception_data = type { i8*, i8 }
+%struct._iobuf = type { i8* }
+%struct.__crt_locale_pointers = type { %struct.__crt_locale_data*, %struct.__crt_multibyte_data* }
+%struct.__crt_locale_data = type opaque
+%struct.__crt_multibyte_data = type opaque
+
+$"??0exception@std@@QEAA@QEBD@Z" = comdat any
+
+$"??0exception@std@@QEAA@AEBV01@@Z" = comdat any
+
+$"??1exception@std@@UEAA@XZ" = comdat any
+
+$printf = comdat any
+
+$"??_Gexception@std@@UEAAPEAXI@Z" = comdat any
+
+$"?what@exception@std@@UEBAPEBDXZ" = comdat any
+
+$_vfprintf_l = comdat any
+
+$__local_stdio_printf_options = comdat any
+
+$"??_C@_00CNPNBAHC@?$AA@" = comdat any
+
+$"??_R0?AVexception@std@@@8" = comdat any
+
+$"_CT??_R0?AVexception@std@@@8??0exception@std@@QEAA@AEBV01@@Z24" = comdat any
+
+$"_CTA1?AVexception@std@@" = comdat any
+
+$"_TI1?AVexception@std@@" = comdat any
+
+$"??_C@_0BP@FDNHNJIN@Executing?5SEH?5__except?5block?$AN?6?$AA@" = comdat any
+
+$"??_7exception@std@@6B@" = comdat largest
+
+$"??_R4exception@std@@6B@" = comdat any
+
+$"??_R3exception@std@@8" = comdat any
+
+$"??_R2exception@std@@8" = comdat any
+
+$"??_R1A@?0A@EA@exception@std@@8" = comdat any
+
+$"??_C@_0BC@EOODALEL@Unknown?5exception?$AA@" = comdat any
+
+$"?_OptionsStorage@?1??__local_stdio_printf_options@@9@4_KA" = comdat any
+
+@"??_C@_00CNPNBAHC@?$AA@" = linkonce_odr dso_local unnamed_addr constant [1 x i8] zeroinitializer, comdat, align 1
+@"??_7type_info@@6B@" = external constant i8*
+@"??_R0?AVexception@std@@@8" = linkonce_odr global %rtti.TypeDescriptor19 { i8** @"??_7type_info@@6B@", i8* null, [20 x i8] c".?AVexception@std@@\00" }, comdat
+@__ImageBase = external dso_local constant i8
+@"_CT??_R0?AVexception@std@@@8??0exception@std@@QEAA@AEBV01@@Z24" = linkonce_odr unnamed_addr constant %eh.CatchableType { i32 0, i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%rtti.TypeDescriptor19* @"??_R0?AVexception@std@@@8" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32), i32 0, i32 -1, i32 0, i32 24, i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%"class.std::exception"* (%"class.std::exception"*, %"class.std::exception"*)* @"??0exception@std@@QEAA@AEBV01@@Z" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32) }, section ".xdata", comdat
+@"_CTA1?AVexception@std@@" = linkonce_odr unnamed_addr constant %eh.CatchableTypeArray.1 { i32 1, [1 x i32] [i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%eh.CatchableType* @"_CT??_R0?AVexception@std@@@8??0exception@std@@QEAA@AEBV01@@Z24" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32)] }, section ".xdata", comdat
+@"_TI1?AVexception@std@@" = linkonce_odr unnamed_addr constant %eh.ThrowInfo { i32 0, i32 trunc (i64 sub nuw nsw (i64 ptrtoint (void (%"class.std::exception"*)* @"??1exception@std@@UEAA@XZ" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32), i32 0, i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%eh.CatchableTypeArray.1* @"_CTA1?AVexception@std@@" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32) }, section ".xdata", comdat
+@"??_C@_0BP@FDNHNJIN@Executing?5SEH?5__except?5block?$AN?6?$AA@" = linkonce_odr dso_local unnamed_addr constant [31 x i8] c"Executing SEH __except block\0D\0A\00", comdat, align 1
+@0 = private unnamed_addr constant { [3 x i8*] } { [3 x i8*] [i8* bitcast (%rtti.CompleteObjectLocator* @"??_R4exception@std@@6B@" to i8*), i8* bitcast (i8* (%"class.std::exception"*, i32)* @"??_Gexception@std@@UEAAPEAXI@Z" to i8*), i8* bitcast (i8* (%"class.std::exception"*)* @"?what@exception@std@@UEBAPEBDXZ" to i8*)] }, comdat($"??_7exception@std@@6B@")
+@"??_R4exception@std@@6B@" = linkonce_odr constant %rtti.CompleteObjectLocator { i32 1, i32 0, i32 0, i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%rtti.TypeDescriptor19* @"??_R0?AVexception@std@@@8" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32), i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%rtti.ClassHierarchyDescriptor* @"??_R3exception@std@@8" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32), i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%rtti.CompleteObjectLocator* @"??_R4exception@std@@6B@" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32) }, comdat
+@"??_R3exception@std@@8" = linkonce_odr constant %rtti.ClassHierarchyDescriptor { i32 0, i32 0, i32 1, i32 trunc (i64 sub nuw nsw (i64 ptrtoint ([2 x i32]* @"??_R2exception@std@@8" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32) }, comdat
+@"??_R2exception@std@@8" = linkonce_odr constant [2 x i32] [i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%rtti.BaseClassDescriptor* @"??_R1A@?0A@EA@exception@std@@8" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32), i32 0], comdat
+@"??_R1A@?0A@EA@exception@std@@8" = linkonce_odr constant %rtti.BaseClassDescriptor { i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%rtti.TypeDescriptor19* @"??_R0?AVexception@std@@@8" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32), i32 0, i32 0, i32 -1, i32 0, i32 64, i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%rtti.ClassHierarchyDescriptor* @"??_R3exception@std@@8" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32) }, comdat
+@"??_C@_0BC@EOODALEL@Unknown?5exception?$AA@" = linkonce_odr dso_local unnamed_addr constant [18 x i8] c"Unknown exception\00", comdat, align 1
+@"?_OptionsStorage@?1??__local_stdio_printf_options@@9@4_KA" = linkonce_odr dso_local global i64 0, comdat, align 8
+
+@"??_7exception@std@@6B@" = unnamed_addr alias i8*, getelementptr inbounds ({ [3 x i8*] }, { [3 x i8*] }* @0, i32 0, i32 0, i32 1)
+
+; Function Attrs: noinline norecurse optnone uwtable mustprogress
+define dso_local i32 @main() #0 personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*) {
+  %1 = alloca i32, align 4
+  %2 = alloca i32, align 4
+  %3 = alloca %"class.std::exception", align 8
+  store i32 0, i32* %1, align 4
+  %4 = invoke %"class.std::exception"* @"??0exception@std@@QEAA@QEBD@Z"(%"class.std::exception"* nonnull dereferenceable(24) %3, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @"??_C@_00CNPNBAHC@?$AA@", i64 0, i64 0)) #10
+          to label %5 unwind label %7
+
+5:                                                ; preds = %0
+  %6 = bitcast %"class.std::exception"* %3 to i8*
+  invoke void @_CxxThrowException(i8* %6, %eh.ThrowInfo* @"_TI1?AVexception@std@@") #11
+          to label %15 unwind label %7
+
+7:                                                ; preds = %5, %0
+  %8 = catchswitch within none [label %9] unwind to caller
+
+9:                                                ; preds = %7
+  %10 = catchpad within %8 [i8* null]
+  catchret from %10 to label %11
+
+11:                                               ; preds = %9
+  %12 = call i32 @llvm.eh.exceptioncode(token %10)
+  store i32 %12, i32* %2, align 4
+  %13 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([31 x i8], [31 x i8]* @"??_C@_0BP@FDNHNJIN@Executing?5SEH?5__except?5block?$AN?6?$AA@", i64 0, i64 0))
+  br label %14
+
+14:                                               ; preds = %11
+  ret i32 0
+
+15:                                               ; preds = %5
+  unreachable
+}
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr dso_local %"class.std::exception"* @"??0exception@std@@QEAA@QEBD@Z"(%"class.std::exception"* nonnull returned dereferenceable(24) %0, i8* %1) unnamed_addr #1 comdat align 2 personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*) {
+  %3 = alloca i8*, align 8
+  %4 = alloca %"class.std::exception"*, align 8
+  %5 = alloca %struct.__std_exception_data, align 8
+  store i8* %1, i8** %3, align 8
+  store %"class.std::exception"* %0, %"class.std::exception"** %4, align 8
+  %6 = load %"class.std::exception"*, %"class.std::exception"** %4, align 8
+  %7 = bitcast %"class.std::exception"* %6 to i32 (...)***
+  store i32 (...)** bitcast (i8** @"??_7exception@std@@6B@" to i32 (...)**), i32 (...)*** %7, align 8
+  %8 = getelementptr inbounds %"class.std::exception", %"class.std::exception"* %6, i32 0, i32 1
+  %9 = bitcast %struct.__std_exception_data* %8 to i8*
+  call void @llvm.memset.p0i8.i64(i8* align 8 %9, i8 0, i64 16, i1 false)
+  %10 = getelementptr inbounds %struct.__std_exception_data, %struct.__std_exception_data* %5, i32 0, i32 0
+  %11 = load i8*, i8** %3, align 8
+  store i8* %11, i8** %10, align 8
+  %12 = getelementptr inbounds %struct.__std_exception_data, %struct.__std_exception_data* %5, i32 0, i32 1
+  store i8 1, i8* %12, align 8
+  %13 = getelementptr inbounds %"class.std::exception", %"class.std::exception"* %6, i32 0, i32 1
+  invoke void @__std_exception_copy(%struct.__std_exception_data* %5, %struct.__std_exception_data* %13)
+          to label %14 unwind label %15
+
+14:                                               ; preds = %2
+  ret %"class.std::exception"* %6
+
+15:                                               ; preds = %2
+  %16 = cleanuppad within none []
+  call void @__std_terminate() #12 [ "funclet"(token %16) ]
+  unreachable
+}
+
+declare dso_local i32 @__C_specific_handler(...)
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr dso_local %"class.std::exception"* @"??0exception@std@@QEAA@AEBV01@@Z"(%"class.std::exception"* nonnull returned dereferenceable(24) %0, %"class.std::exception"* nonnull align 8 dereferenceable(24) %1) unnamed_addr #1 comdat align 2 personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*) {
+  %3 = alloca %"class.std::exception"*, align 8
+  %4 = alloca %"class.std::exception"*, align 8
+  store %"class.std::exception"* %1, %"class.std::exception"** %3, align 8
+  store %"class.std::exception"* %0, %"class.std::exception"** %4, align 8
+  %5 = load %"class.std::exception"*, %"class.std::exception"** %4, align 8
+  %6 = bitcast %"class.std::exception"* %5 to i32 (...)***
+  store i32 (...)** bitcast (i8** @"??_7exception@std@@6B@" to i32 (...)**), i32 (...)*** %6, align 8
+  %7 = getelementptr inbounds %"class.std::exception", %"class.std::exception"* %5, i32 0, i32 1
+  %8 = bitcast %struct.__std_exception_data* %7 to i8*
+  call void @llvm.memset.p0i8.i64(i8* align 8 %8, i8 0, i64 16, i1 false)
+  %9 = getelementptr inbounds %"class.std::exception", %"class.std::exception"* %5, i32 0, i32 1
+  %10 = load %"class.std::exception"*, %"class.std::exception"** %3, align 8
+  %11 = getelementptr inbounds %"class.std::exception", %"class.std::exception"* %10, i32 0, i32 1
+  invoke void @__std_exception_copy(%struct.__std_exception_data* %11, %struct.__std_exception_data* %9)
+          to label %12 unwind label %13
+
+12:                                               ; preds = %2
+  ret %"class.std::exception"* %5
+
+13:                                               ; preds = %2
+  %14 = cleanuppad within none []
+  call void @__std_terminate() #12 [ "funclet"(token %14) ]
+  unreachable
+}
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr dso_local void @"??1exception@std@@UEAA@XZ"(%"class.std::exception"* nonnull dereferenceable(24) %0) unnamed_addr #1 comdat align 2 personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*) {
+  %2 = alloca %"class.std::exception"*, align 8
+  store %"class.std::exception"* %0, %"class.std::exception"** %2, align 8
+  %3 = load %"class.std::exception"*, %"class.std::exception"** %2, align 8
+  %4 = bitcast %"class.std::exception"* %3 to i32 (...)***
+  store i32 (...)** bitcast (i8** @"??_7exception@std@@6B@" to i32 (...)**), i32 (...)*** %4, align 8
+  %5 = getelementptr inbounds %"class.std::exception", %"class.std::exception"* %3, i32 0, i32 1
+  invoke void @__std_exception_destroy(%struct.__std_exception_data* %5)
+          to label %6 unwind label %7
+
+6:                                                ; preds = %1
+  ret void
+
+7:                                                ; preds = %1
+  %8 = cleanuppad within none []
+  call void @__std_terminate() #12 [ "funclet"(token %8) ]
+  unreachable
+}
+
+declare dso_local void @_CxxThrowException(i8*, %eh.ThrowInfo*)
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.eh.exceptioncode(token) #2
+
+; Function Attrs: nobuiltin noinline optnone uwtable mustprogress
+define linkonce_odr dso_local i32 @printf(i8* %0, ...) #3 comdat {
+  %2 = alloca i8*, align 8
+  %3 = alloca i32, align 4
+  %4 = alloca i8*, align 8
+  store i8* %0, i8** %2, align 8
+  %5 = bitcast i8** %4 to i8*
+  call void @llvm.va_start(i8* %5)
+  %6 = load i8*, i8** %4, align 8
+  %7 = load i8*, i8** %2, align 8
+  %8 = call %struct._iobuf* @__acrt_iob_func(i32 1)
+  %9 = call i32 @_vfprintf_l(%struct._iobuf* %8, i8* %7, %struct.__crt_locale_pointers* null, i8* %6)
+  store i32 %9, i32* %3, align 4
+  %10 = bitcast i8** %4 to i8*
+  call void @llvm.va_end(i8* %10)
+  %11 = load i32, i32* %3, align 4
+  ret i32 %11
+}
+
+; Function Attrs: argmemonly nofree nosync nounwind willreturn writeonly
+declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i1 immarg) #4
+
+declare dso_local void @__std_exception_copy(%struct.__std_exception_data*, %struct.__std_exception_data*) #5
+
+declare dso_local i32 @__CxxFrameHandler3(...)
+
+declare dso_local void @__std_terminate()
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr dso_local i8* @"??_Gexception@std@@UEAAPEAXI@Z"(%"class.std::exception"* nonnull dereferenceable(24) %0, i32 %1) unnamed_addr #1 comdat align 2 {
+  %3 = alloca i8*, align 8
+  %4 = alloca i32, align 4
+  %5 = alloca %"class.std::exception"*, align 8
+  store i32 %1, i32* %4, align 4
+  store %"class.std::exception"* %0, %"class.std::exception"** %5, align 8
+  %6 = load %"class.std::exception"*, %"class.std::exception"** %5, align 8
+  %7 = bitcast %"class.std::exception"* %6 to i8*
+  store i8* %7, i8** %3, align 8
+  %8 = load i32, i32* %4, align 4
+  call void @"??1exception@std@@UEAA@XZ"(%"class.std::exception"* nonnull dereferenceable(24) %6) #13
+  %9 = icmp eq i32 %8, 0
+  br i1 %9, label %12, label %10
+
+10:                                               ; preds = %2
+  %11 = bitcast %"class.std::exception"* %6 to i8*
+  call void @"??3@YAXPEAX@Z"(i8* %11) #14
+  br label %12
+
+12:                                               ; preds = %10, %2
+  %13 = load i8*, i8** %3, align 8
+  ret i8* %13
+}
+
+; Function Attrs: noinline nounwind optnone uwtable mustprogress
+define linkonce_odr dso_local i8* @"?what@exception@std@@UEBAPEBDXZ"(%"class.std::exception"* nonnull dereferenceable(24) %0) unnamed_addr #6 comdat align 2 {
+  %2 = alloca %"class.std::exception"*, align 8
+  store %"class.std::exception"* %0, %"class.std::exception"** %2, align 8
+  %3 = load %"class.std::exception"*, %"class.std::exception"** %2, align 8
+  %4 = getelementptr inbounds %"class.std::exception", %"class.std::exception"* %3, i32 0, i32 1
+  %5 = getelementptr inbounds %struct.__std_exception_data, %struct.__std_exception_data* %4, i32 0, i32 0
+  %6 = load i8*, i8** %5, align 8
+  %7 = icmp ne i8* %6, null
+  br i1 %7, label %8, label %12
+
+8:                                                ; preds = %1
+  %9 = getelementptr inbounds %"class.std::exception", %"class.std::exception"* %3, i32 0, i32 1
+  %10 = getelementptr inbounds %struct.__std_exception_data, %struct.__std_exception_data* %9, i32 0, i32 0
+  %11 = load i8*, i8** %10, align 8
+  br label %13
+
+12:                                               ; preds = %1
+  br label %13
+
+13:                                               ; preds = %12, %8
+  %14 = phi i8* [ %11, %8 ], [ getelementptr inbounds ([18 x i8], [18 x i8]* @"??_C@_0BC@EOODALEL@Unknown?5exception?$AA@", i64 0, i64 0), %12 ]
+  ret i8* %14
+}
+
+; Function Attrs: nobuiltin nounwind
+declare dso_local void @"??3@YAXPEAX@Z"(i8*) #7
+
+declare dso_local void @__std_exception_destroy(%struct.__std_exception_data*) #5
+
+; Function Attrs: nofree nosync nounwind willreturn
+declare void @llvm.va_start(i8*) #8
+
+; Function Attrs: noinline optnone uwtable mustprogress
+define linkonce_odr dso_local i32 @_vfprintf_l(%struct._iobuf* %0, i8* %1, %struct.__crt_locale_pointers* %2, i8* %3) #9 comdat {
+  %5 = alloca i8*, align 8
+  %6 = alloca %struct.__crt_locale_pointers*, align 8
+  %7 = alloca i8*, align 8
+  %8 = alloca %struct._iobuf*, align 8
+  store i8* %3, i8** %5, align 8
+  store %struct.__crt_locale_pointers* %2, %struct.__crt_locale_pointers** %6, align 8
+  store i8* %1, i8** %7, align 8
+  store %struct._iobuf* %0, %struct._iobuf** %8, align 8
+  %9 = load i8*, i8** %5, align 8
+  %10 = load %struct.__crt_locale_pointers*, %struct.__crt_locale_pointers** %6, align 8
+  %11 = load i8*, i8** %7, align 8
+  %12 = load %struct._iobuf*, %struct._iobuf** %8, align 8
+  %13 = call i64* @__local_stdio_printf_options()
+  %14 = load i64, i64* %13, align 8
+  %15 = call i32 @__stdio_common_vfprintf(i64 %14, %struct._iobuf* %12, i8* %11, %struct.__crt_locale_pointers* %10, i8* %9)
+  ret i32 %15
+}
+
+declare dso_local %struct._iobuf* @__acrt_iob_func(i32) #5
+
+; Function Attrs: nofree nosync nounwind willreturn
+declare void @llvm.va_end(i8*) #8
+
+declare dso_local i32 @__stdio_common_vfprintf(i64, %struct._iobuf*, i8*, %struct.__crt_locale_pointers*, i8*) #5
+
+; Function Attrs: noinline nounwind optnone uwtable mustprogress
+define linkonce_odr dso_local i64* @__local_stdio_printf_options() #6 comdat {
+  ret i64* @"?_OptionsStorage@?1??__local_stdio_printf_options@@9@4_KA"
+}
+
+attributes #0 = { noinline norecurse optnone uwtable mustprogress "frame-pointer"="none" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #1 = { noinline nounwind optnone uwtable "frame-pointer"="none" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #2 = { nounwind readnone }
+attributes #3 = { nobuiltin noinline optnone uwtable mustprogress "frame-pointer"="none" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #4 = { argmemonly nofree nosync nounwind willreturn writeonly }
+attributes #5 = { "frame-pointer"="none" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #6 = { noinline nounwind optnone uwtable mustprogress "frame-pointer"="none" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #7 = { nobuiltin nounwind "frame-pointer"="none" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #8 = { nofree nosync nounwind willreturn }
+attributes #9 = { noinline optnone uwtable mustprogress "frame-pointer"="none" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #10 = { noinline nounwind }
+attributes #11 = { noreturn }
+attributes #12 = { noreturn nounwind }
+attributes #13 = { nounwind }
+attributes #14 = { builtin nounwind }
+
+!llvm.linker.options = !{!0, !1, !1, !2, !3, !4, !5}
+!llvm.module.flags = !{!6, !7}
+!llvm.ident = !{!8}
+
+!0 = !{!"/FAILIFMISMATCH:\22_CRT_STDIO_ISO_WIDE_SPECIFIERS=0\22"}
+!1 = !{!"/DEFAULTLIB:uuid.lib"}
+!2 = !{!"/FAILIFMISMATCH:\22_MSC_VER=1900\22"}
+!3 = !{!"/FAILIFMISMATCH:\22_ITERATOR_DEBUG_LEVEL=0\22"}
+!4 = !{!"/FAILIFMISMATCH:\22RuntimeLibrary=MT_StaticRelease\22"}
+!5 = !{!"/DEFAULTLIB:libcpmt.lib"}
+!6 = !{i32 1, !"wchar_size", i32 2}
+!7 = !{i32 7, !"PIC Level", i32 2}
+!8 = !{!"clang version 13.0.0 (https://github.com/llvm/llvm-project.git 30f591c3869f3bbe6eca1249dcef1b8337312de6)"}