Add the ExceptionHandling::MSVC enumeration

It is intended to be used for a family of personality functions that
have similar IR preparation requirements. Typically when interoperating
with MSVC personality functions, bits of functionality need to be
outlined from the main function into helper functions. There is also
usually more than one landing pad per invoke, which does not match the
LLVM IR landingpad representation.

None of this is implemented yet. This change just adds a new enum that
is active for *-windows-msvc and delegates to the EH removal preparation
pass.  No functionality change for other targets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224625 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCAsmInfo.h

@@ -47,6 +47,7 @@ enum class ExceptionHandling {
   SjLj,         /// setjmp/longjmp based exceptions
   ARM,          /// ARM EHABI
   ItaniumWinEH, /// Itanium EH built on Windows unwind info (.pdata and .xdata)
+  MSVC,         /// MSVC compatible exception handling
 };
 
 namespace LCOMM {
@@ -492,6 +493,11 @@ public:
             ExceptionsType == ExceptionHandling::ItaniumWinEH);
   }
 
+  bool usesWindowsCFI() const {
+    return ExceptionsType == ExceptionHandling::ItaniumWinEH ||
+           ExceptionsType == ExceptionHandling::MSVC;
+  }
+
   bool doesDwarfUseRelocationsAcrossSections() const {
     return DwarfUsesRelocationsAcrossSections;
   }

lib/CodeGen/AsmPrinter/AsmPrinter.cpp

@@ -242,6 +242,7 @@ bool AsmPrinter::doInitialization(Module &M) {
     ES = new ARMException(this);
     break;
   case ExceptionHandling::ItaniumWinEH:
+  case ExceptionHandling::MSVC:
     switch (MAI->getWinEHEncodingType()) {
     default: llvm_unreachable("unsupported unwinding information encoding");
     case WinEH::EncodingType::Itanium:
@@ -705,8 +706,7 @@ AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
 }
 
 bool AsmPrinter::needsSEHMoves() {
-  return MAI->getExceptionHandlingType() == ExceptionHandling::ItaniumWinEH &&
+  return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
-         MF->getFunction()->needsUnwindTableEntry();
 }
 
 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {

lib/CodeGen/AsmPrinter/EHStreamer.cpp

@@ -208,6 +208,8 @@ computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
   // Whether the last CallSite entry was for an invoke.
   bool PreviousIsInvoke = false;
 
+  bool IsSJLJ = Asm->MAI->getExceptionHandlingType() == ExceptionHandling::SjLj;
+
   // Visit all instructions in order of address.
   for (const auto &MBB : *Asm->MF) {
     for (const auto &MI : MBB) {
@@ -237,7 +239,7 @@ computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
       // instruction between the previous try-range and this one may throw,
       // create a call-site entry with no landing pad for the region between the
       // try-ranges.
-      if (SawPotentiallyThrowing && Asm->MAI->usesItaniumLSDAForExceptions()) {
+      if (SawPotentiallyThrowing && !IsSJLJ) {
         CallSiteEntry Site = { LastLabel, BeginLabel, nullptr, 0 };
         CallSites.push_back(Site);
         PreviousIsInvoke = false;
@@ -259,7 +261,7 @@ computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
         };
 
         // Try to merge with the previous call-site. SJLJ doesn't do this
-        if (PreviousIsInvoke && Asm->MAI->usesItaniumLSDAForExceptions()) {
+        if (PreviousIsInvoke && !IsSJLJ) {
           CallSiteEntry &Prev = CallSites.back();
           if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
             // Extend the range of the previous entry.
@@ -269,7 +271,7 @@ computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
         }
 
         // Otherwise, create a new call-site.
-        if (Asm->MAI->usesItaniumLSDAForExceptions())
+        if (!IsSJLJ)
           CallSites.push_back(Site);
         else {
           // SjLj EH must maintain the call sites in the order assigned
@@ -287,7 +289,7 @@ computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
   // If some instruction between the previous try-range and the end of the
   // function may throw, create a call-site entry with no landing pad for the
   // region following the try-range.
-  if (SawPotentiallyThrowing && Asm->MAI->usesItaniumLSDAForExceptions()) {
+  if (SawPotentiallyThrowing && !IsSJLJ) {
     CallSiteEntry Site = { LastLabel, nullptr, nullptr, 0 };
     CallSites.push_back(Site);
   }
@@ -519,8 +521,7 @@ void EHStreamer::emitExceptionTable() {
       Asm->EmitULEB128(S.Action);
     }
   } else {
-    // DWARF Exception handling
+    // Itanium LSDA exception handling
-    assert(Asm->MAI->usesItaniumLSDAForExceptions());
 
     // The call-site table is a list of all call sites that may throw an
     // exception (including C++ 'throw' statements) in the procedure

lib/CodeGen/Passes.cpp

@@ -451,6 +451,7 @@ void TargetPassConfig::addPassesToHandleExceptions() {
   case ExceptionHandling::ItaniumWinEH:
     addPass(createDwarfEHPass(TM));
     break;
+  case ExceptionHandling::MSVC: // FIXME: Add preparation.
   case ExceptionHandling::None:
     addPass(createLowerInvokePass());
 

lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp

@@ -137,7 +137,9 @@ X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
     PrivateLabelPrefix = ".L";
     PointerSize = 8;
     WinEHEncodingType = WinEH::EncodingType::Itanium;
-    ExceptionsType = ExceptionHandling::ItaniumWinEH;
+
+    // Use MSVC-compatible EH data.
+    ExceptionsType = ExceptionHandling::MSVC;
   }
 
   AssemblerDialect = AsmWriterFlavor;

lib/Target/X86/X86FrameLowering.cpp

@@ -495,8 +495,7 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
   const bool Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
   bool IsWin64 = STI.isTargetWin64();
   // Not necessarily synonymous with IsWin64.
-  bool IsWinEH = MF.getTarget().getMCAsmInfo()->getExceptionHandlingType() ==
+  bool IsWinEH = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
-                 ExceptionHandling::ItaniumWinEH;
   bool NeedsWinEH = IsWinEH && Fn->needsUnwindTableEntry();
   bool NeedsDwarfCFI =
       !IsWinEH && (MMI.hasDebugInfo() || Fn->needsUnwindTableEntry());
@@ -906,8 +905,7 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
              getX86SubSuperRegister(FramePtr, MVT::i64, false) : FramePtr;
   unsigned StackPtr = RegInfo->getStackRegister();
 
-  bool IsWinEH = MF.getTarget().getMCAsmInfo()->getExceptionHandlingType() ==
+  bool IsWinEH = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
-                 ExceptionHandling::ItaniumWinEH;
   bool NeedsWinEH = IsWinEH && MF.getFunction()->needsUnwindTableEntry();
 
   switch (RetOpcode) {

test/CodeGen/X86/fast-isel-cmp-branch.ll

@@ -1,5 +1,5 @@
 ; RUN: llc -O0 -mtriple=x86_64-linux -asm-verbose=false < %s | FileCheck %s
-; RUN: llc -O0 -mtriple=x86_64-win32 -asm-verbose=false < %s | FileCheck %s
+; RUN: llc -O0 -mtriple=x86_64-windows-itanium -asm-verbose=false < %s | FileCheck %s
 ; rdar://8337108
 
 ; Fast-isel shouldn't try to look through the compare because it's in a

test/CodeGen/X86/fast-isel-gep.ll

@@ -1,5 +1,5 @@
 ; RUN: llc < %s -mtriple=x86_64-linux -O0 | FileCheck %s --check-prefix=X64
-; RUN: llc < %s -mtriple=x86_64-win32 -O0 | FileCheck %s --check-prefix=X64
+; RUN: llc < %s -mtriple=x86_64-windows-itanium -O0 | FileCheck %s --check-prefix=X64
 ; RUN: llc < %s -march=x86 -O0 | FileCheck %s --check-prefix=X32
 
 ; GEP indices are interpreted as signed integers, so they

test/CodeGen/X86/scev-interchange.ll

@@ -1,4 +1,4 @@
-; RUN: llc < %s -march=x86-64
+; RUN: llc < %s -mtriple=x86_64-linux
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
 	%"struct.DataOutBase::GmvFlags" = type { i32 }

test/CodeGen/X86/win64_eh.ll

@@ -1,4 +1,4 @@
-; RUN: llc < %s -O0 -mcpu=corei7 -mtriple=x86_64-pc-win32 | FileCheck %s -check-prefix=WIN64
+; RUN: llc < %s -O0 -mcpu=corei7 -mtriple=x86_64-pc-windows-itanium | FileCheck %s -check-prefix=WIN64
 ; RUN: llc < %s -O0 -mcpu=corei7 -mtriple=x86_64-pc-mingw32 | FileCheck %s -check-prefix=WIN64
 
 ; Check function without prolog