Classify functions by EH personality type rather than using the triple

This mostly reverts commit r222062 and replaces it with a new enum. At
some point this enum will grow at least for other MSVC EH personalities.

Also beefs up the way we were sniffing the personality function.
Previously we would emit the Itanium LSDA despite using
__C_specific_handler.

Reviewers: majnemer

Differential Revision: http://reviews.llvm.org/D6987

llvm-svn: 226920

7 files changed, 30 insertions, 13 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index a57807f8ee9..8206d088b99 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -254,8 +254,7 @@ bool AsmPrinter::doInitialization(Module &M) {
   case ExceptionHandling::ARM:
     ES = new ARMException(this);
     break;
-  case ExceptionHandling::ItaniumWinEH:
-  case ExceptionHandling::MSVC:
+  case ExceptionHandling::WinEH:
     switch (MAI->getWinEHEncodingType()) {
     default: llvm_unreachable("unsupported unwinding information encoding");
     case WinEH::EncodingType::Itanium:
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
index 0bbe1ab1e5c..f45b24c17f7 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
@@ -51,7 +51,8 @@ void DwarfCFIException::endModule() {
   if (moveTypeModule == AsmPrinter::CFI_M_Debug)
     Asm->OutStreamer.EmitCFISections(false, true);
 
-  if (!Asm->MAI->usesItaniumLSDAForExceptions())
+  // SjLj uses this pass and it doesn't need this info.
+  if (!Asm->MAI->usesCFIForEH())
     return;
 
   const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
diff --git a/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp b/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp
index 1bc86f6c222..4841814afff 100644
--- a/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp
@@ -253,7 +253,7 @@ 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 && !IsSJLJ) {
+      if (SawPotentiallyThrowing && Asm->MAI->usesCFIForEH()) {
         CallSiteEntry Site = { LastLabel, BeginLabel, nullptr, 0 };
         CallSites.push_back(Site);
         PreviousIsInvoke = false;
diff --git a/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp b/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp
index 73278c835bc..a1719a51889 100644
--- a/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp
@@ -105,8 +105,8 @@ void Win64Exception::endFunction(const MachineFunction *) {
 
     // Emit the tables appropriate to the personality function in use. If we
     // don't recognize the personality, assume it uses an Itanium-style LSDA.
-    const Function *Per = MMI->getPersonality();
-    if (Per && Per->getName() == "__C_specific_handler")
+    EHPersonality Per = MMI->getPersonalityType();
+    if (Per == EHPersonality::Win64SEH)
       emitCSpecificHandlerTable();
     else
       emitExceptionTable();
diff --git a/llvm/lib/CodeGen/MachineModuleInfo.cpp b/llvm/lib/CodeGen/MachineModuleInfo.cpp
index b5a31925e6b..b4ce673659f 100644
--- a/llvm/lib/CodeGen/MachineModuleInfo.cpp
+++ b/llvm/lib/CodeGen/MachineModuleInfo.cpp
@@ -276,6 +276,7 @@ bool MachineModuleInfo::doInitialization(Module &M) {
   DbgInfoAvailable = UsesVAFloatArgument = UsesMorestackAddr = false;
   // Always emit some info, by default "no personality" info.
   Personalities.push_back(nullptr);
+  PersonalityTypeCache = EHPersonality::None;
   AddrLabelSymbols = nullptr;
   TheModule = nullptr;
 
@@ -554,7 +555,21 @@ try_next:;
 
 /// getPersonality - Return the personality function for the current function.
 const Function *MachineModuleInfo::getPersonality() const {
-  return !LandingPads.empty() ? LandingPads[0].Personality : nullptr;
+  for (const LandingPadInfo &LPI : LandingPads)
+    if (LPI.Personality)
+      return LPI.Personality;
+  return nullptr;
+}
+
+EHPersonality MachineModuleInfo::getPersonalityTypeSlow() {
+  const Function *Per = getPersonality();
+  if (!Per)
+    PersonalityTypeCache = EHPersonality::None;
+  else if (Per->getName() == "__C_specific_handler")
+    PersonalityTypeCache = EHPersonality::Win64SEH;
+  else // Assume everything else is Itanium.
+    PersonalityTypeCache = EHPersonality::Itanium;
+  return PersonalityTypeCache;
 }
 
 /// getPersonalityIndex - Return unique index for current personality
diff --git a/llvm/lib/CodeGen/Passes.cpp b/llvm/lib/CodeGen/Passes.cpp
index 88cee03fa16..0797f2335c2 100644
--- a/llvm/lib/CodeGen/Passes.cpp
+++ b/llvm/lib/CodeGen/Passes.cpp
@@ -447,8 +447,7 @@ void TargetPassConfig::addPassesToHandleExceptions() {
     // FALLTHROUGH
   case ExceptionHandling::DwarfCFI:
   case ExceptionHandling::ARM:
-  case ExceptionHandling::ItaniumWinEH:
-  case ExceptionHandling::MSVC: // FIXME: Needs preparation.
+  case ExceptionHandling::WinEH:
     addPass(createDwarfEHPass(TM));
     break;
   case ExceptionHandling::None:
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index d37de980e06..c56973a44fa 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -924,8 +924,13 @@ void SelectionDAGISel::PrepareEHLandingPad() {
   BuildMI(*MBB, FuncInfo->InsertPt, SDB->getCurDebugLoc(), II)
     .addSym(Label);
 
-  if (TM.getMCAsmInfo()->getExceptionHandlingType() ==
-      ExceptionHandling::MSVC) {
+  // If this is an MSVC-style personality function, we need to split the landing
+  // pad into several BBs.
+  const BasicBlock *LLVMBB = MBB->getBasicBlock();
+  const LandingPadInst *LPadInst = LLVMBB->getLandingPadInst();
+  MF->getMMI().addPersonality(
+      MBB, cast<Function>(LPadInst->getPersonalityFn()->stripPointerCasts()));
+  if (MF->getMMI().getPersonalityType() == EHPersonality::Win64SEH) {
     // Make virtual registers and a series of labels that fill in values for the
     // clauses.
     auto &RI = MF->getRegInfo();
@@ -937,8 +942,6 @@ void SelectionDAGISel::PrepareEHLandingPad() {
 
     // Emit separate machine basic blocks with separate labels for each clause
     // before the main landing pad block.
-    const BasicBlock *LLVMBB = MBB->getBasicBlock();
-    const LandingPadInst *LPadInst = LLVMBB->getLandingPadInst();
     MachineInstrBuilder SelectorPHI = BuildMI(
         *MBB, MBB->begin(), SDB->getCurDebugLoc(), TII->get(TargetOpcode::PHI),
         FuncInfo->ExceptionSelectorVirtReg);