Rename EH related stuff to be more precise

Summary:
The current "WinEH" exception handling type is more about Itanium-style
LSDA tables layered on top of the Windows native unwind info format
instead of .eh_frame tables or EHABI unwind info. Use the name
"ItaniumWinEH" to better reflect the hybrid nature of the design.

Also rename isExceptionHandlingDWARF to usesItaniumLSDAForExceptions,
since the LSDA is part of the Itanium C++ ABI document, and not the
DWARF standard.

Reviewers: echristo

Subscribers: llvm-commits, compnerd

Differential Revision: http://reviews.llvm.org/D6279

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222062 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/MC/MCAsmInfo.h b/include/llvm/MC/MCAsmInfo.h
index 7740fef612271cb647e134520e80f8e6f954bf7d..4f38aacd3b2202f81959d34f07a9932b7ee6d0a1 100644 (file)
--- a/include/llvm/MC/MCAsmInfo.h
+++ b/include/llvm/MC/MCAsmInfo.h
@@ -42,11 +42,11 @@ enum class EncodingType {
 }
 
 enum class ExceptionHandling {
-  None,     /// No exception support
-  DwarfCFI, /// DWARF-like instruction based exceptions
-  SjLj,     /// setjmp/longjmp based exceptions
-  ARM,      /// ARM EHABI
-  WinEH,    /// Windows Exception Handling
+  None,         /// No exception support
+  DwarfCFI,     /// DWARF-like instruction based exceptions
+  SjLj,         /// setjmp/longjmp based exceptions
+  ARM,          /// ARM EHABI
+  ItaniumWinEH, /// Itanium EH built on Windows unwind info (.pdata and .xdata)
 };
 
 namespace LCOMM {
@@ -472,12 +472,16 @@ public:
   }
   ExceptionHandling getExceptionHandlingType() const { return ExceptionsType; }
   WinEH::EncodingType getWinEHEncodingType() const { return WinEHEncodingType; }
-  bool isExceptionHandlingDwarf() const {
+
+  /// Return true if the exception handling type uses the language-specific data
+  /// area (LSDA) format specified by the Itanium C++ ABI.
+  bool usesItaniumLSDAForExceptions() const {
     return (ExceptionsType == ExceptionHandling::DwarfCFI ||
             ExceptionsType == ExceptionHandling::ARM ||
-            // Windows handler data still uses DWARF LSDA encoding.
-            ExceptionsType == ExceptionHandling::WinEH);
+            // This Windows EH type uses the Itanium LSDA encoding.
+            ExceptionsType == ExceptionHandling::ItaniumWinEH);
   }
+
   bool doesDwarfUseRelocationsAcrossSections() const {
     return DwarfUsesRelocationsAcrossSections;
   }

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 32bcd6b8158104de8f550af356abda25feea6ff5..70b6b4dd5b8d55d1a5ed3e193c4274ca83fdaed8 100644 (file)
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -241,7 +241,7 @@ bool AsmPrinter::doInitialization(Module &M) {
   case ExceptionHandling::ARM:
     ES = new ARMException(this);
     break;
-  case ExceptionHandling::WinEH:
+  case ExceptionHandling::ItaniumWinEH:
     switch (MAI->getWinEHEncodingType()) {
     default: llvm_unreachable("unsupported unwinding information encoding");
     case WinEH::EncodingType::Itanium:
@@ -701,8 +701,8 @@ AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
 }
 
 bool AsmPrinter::needsSEHMoves() {
-  return MAI->getExceptionHandlingType() == ExceptionHandling::WinEH &&
-    MF->getFunction()->needsUnwindTableEntry();
+  return MAI->getExceptionHandlingType() == ExceptionHandling::ItaniumWinEH &&
+         MF->getFunction()->needsUnwindTableEntry();
 }
 
 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {

diff --git a/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp b/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
index 74215aa695ddbf487f872cc3ae7a621502985539..0dc52dae8f39750675f6c2339701e03dbd2fd108 100644 (file)
--- a/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
@@ -51,7 +51,7 @@ void DwarfCFIException::endModule() {
   if (moveTypeModule == AsmPrinter::CFI_M_Debug)
     Asm->OutStreamer.EmitCFISections(false, true);
 
-  if (!Asm->MAI->isExceptionHandlingDwarf())
+  if (!Asm->MAI->usesItaniumLSDAForExceptions())
     return;
 
   const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();

diff --git a/lib/CodeGen/AsmPrinter/EHStreamer.cpp b/lib/CodeGen/AsmPrinter/EHStreamer.cpp
index 58e524c8a51cfa2ac1d83ee7ad09febd66599a7d..2bbffb3f37038f0de28912e2a7a5b4140c2980bb 100644 (file)
--- a/lib/CodeGen/AsmPrinter/EHStreamer.cpp
+++ b/lib/CodeGen/AsmPrinter/EHStreamer.cpp
@@ -237,7 +237,7 @@ 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->isExceptionHandlingDwarf()) {
+      if (SawPotentiallyThrowing && Asm->MAI->usesItaniumLSDAForExceptions()) {
         CallSiteEntry Site = { LastLabel, BeginLabel, nullptr, 0 };
         CallSites.push_back(Site);
         PreviousIsInvoke = false;
@@ -259,7 +259,7 @@ computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
         };
 
         // Try to merge with the previous call-site. SJLJ doesn't do this
-        if (PreviousIsInvoke && Asm->MAI->isExceptionHandlingDwarf()) {
+        if (PreviousIsInvoke && Asm->MAI->usesItaniumLSDAForExceptions()) {
           CallSiteEntry &Prev = CallSites.back();
           if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
             // Extend the range of the previous entry.
@@ -269,7 +269,7 @@ computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
         }
 
         // Otherwise, create a new call-site.
-        if (Asm->MAI->isExceptionHandlingDwarf())
+        if (Asm->MAI->usesItaniumLSDAForExceptions())
           CallSites.push_back(Site);
         else {
           // SjLj EH must maintain the call sites in the order assigned
@@ -287,7 +287,7 @@ 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->isExceptionHandlingDwarf()) {
+  if (SawPotentiallyThrowing && Asm->MAI->usesItaniumLSDAForExceptions()) {
     CallSiteEntry Site = { LastLabel, nullptr, nullptr, 0 };
     CallSites.push_back(Site);
   }
@@ -520,7 +520,7 @@ void EHStreamer::emitExceptionTable() {
     }
   } else {
     // DWARF Exception handling
-    assert(Asm->MAI->isExceptionHandlingDwarf());
+    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

diff --git a/lib/CodeGen/Passes.cpp b/lib/CodeGen/Passes.cpp
index b8b9311fc8cfa747360184b27755a4a93e5da495..644cc97efcc11ad0c0e226497be2b9f9db22538d 100644 (file)
--- a/lib/CodeGen/Passes.cpp
+++ b/lib/CodeGen/Passes.cpp
@@ -429,7 +429,7 @@ void TargetPassConfig::addPassesToHandleExceptions() {
     // FALLTHROUGH
   case ExceptionHandling::DwarfCFI:
   case ExceptionHandling::ARM:
-  case ExceptionHandling::WinEH:
+  case ExceptionHandling::ItaniumWinEH:
     addPass(createDwarfEHPass(TM));
     break;
   case ExceptionHandling::None:

diff --git a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
index 3a67f6a5f9135b9e9930d2018802380cb7dac5fa..5679d63736de21d152f81e1e99595c8e55f6a315 100644 (file)
--- a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
@@ -137,7 +137,7 @@ X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
     PrivateGlobalPrefix = ".L";
     PointerSize = 8;
     WinEHEncodingType = WinEH::EncodingType::Itanium;
-    ExceptionsType = ExceptionHandling::WinEH;
+    ExceptionsType = ExceptionHandling::ItaniumWinEH;
   }
 
   AssemblerDialect = AsmWriterFlavor;
@@ -157,7 +157,7 @@ X86MCAsmInfoGNUCOFF::X86MCAsmInfoGNUCOFF(const Triple &Triple) {
     PrivateGlobalPrefix = ".L";
     PointerSize = 8;
     WinEHEncodingType = WinEH::EncodingType::Itanium;
-    ExceptionsType = ExceptionHandling::WinEH;
+    ExceptionsType = ExceptionHandling::ItaniumWinEH;
   } else {
     ExceptionsType = ExceptionHandling::DwarfCFI;
   }

diff --git a/lib/Target/X86/X86FrameLowering.cpp b/lib/Target/X86/X86FrameLowering.cpp
index 6e6bedbc5fb8a107986d4a39993e734fa773d6c7..b9920b1b84ceaf6970e9e594df51905bf249261a 100644 (file)
--- a/lib/Target/X86/X86FrameLowering.cpp
+++ b/lib/Target/X86/X86FrameLowering.cpp
@@ -482,9 +482,9 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
   // standard x86_64 and NaCl use 64-bit frame/stack pointers, x32 - 32-bit.
   const bool Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
   bool IsWin64 = STI.isTargetWin64();
-  bool IsWinEH =
-      MF.getTarget().getMCAsmInfo()->getExceptionHandlingType() ==
-      ExceptionHandling::WinEH; // Not necessarily synonymous with IsWin64.
+  // Not necessarily synonymous with IsWin64.
+  bool IsWinEH = MF.getTarget().getMCAsmInfo()->getExceptionHandlingType() ==
+                 ExceptionHandling::ItaniumWinEH;
   bool NeedsWinEH = IsWinEH && Fn->needsUnwindTableEntry();
   bool NeedsDwarfCFI =
       !IsWinEH && (MMI.hasDebugInfo() || Fn->needsUnwindTableEntry());
@@ -883,9 +883,8 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
              getX86SubSuperRegister(FramePtr, MVT::i64, false) : FramePtr;
   unsigned StackPtr = RegInfo->getStackRegister();
 
-  bool IsWinEH =
-      MF.getTarget().getMCAsmInfo()->getExceptionHandlingType() ==
-      ExceptionHandling::WinEH;
+  bool IsWinEH = MF.getTarget().getMCAsmInfo()->getExceptionHandlingType() ==
+                 ExceptionHandling::ItaniumWinEH;
   bool NeedsWinEH = IsWinEH && MF.getFunction()->needsUnwindTableEntry();
 
   switch (RetOpcode) {