Preliminary patch to improve dwarf EH generation - Hooks to return Personality / FDE / LSDA / TType encoding depending on target / options (e.g. code model / relocation model) - MCIzation of Dwarf EH printer to use encoding information - Stub generation for ELF target (needed for indirect references) - Some other small changes here and there

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96285 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 213 insertions, 84 deletions

diff --git a/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp b/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp
index dfcee79..704c013 100644
--- a/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp
+++ b/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp
@@ -603,6 +603,28 @@ void X86AsmPrinter::EmitEndOfAsmFile(Module &M) {
       }
     }
   }
+
+  if (Subtarget->isTargetELF()) {
+    TargetLoweringObjectFileELF &TLOFELF =
+      static_cast<TargetLoweringObjectFileELF &>(getObjFileLowering());
+
+    MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
+
+    // Output stubs for external and common global variables.
+    MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
+    if (!Stubs.empty()) {
+      OutStreamer.SwitchSection(TLOFELF.getDataRelSection());
+      const TargetData *TD = TM.getTargetData();
+
+      for (unsigned i = 0, e = Stubs.size(); i != e; ++i)
+        O << *Stubs[i].first << ":\n"
+          << (TD->getPointerSize() == 8 ?
+              MAI->getData64bitsDirective() : MAI->getData32bitsDirective())
+          << *Stubs[i].second << '\n';
+
+      Stubs.clear();
+    }
+  }
 }
 
 
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index a80f2f8..9974d8c 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -75,13 +75,14 @@ static TargetLoweringObjectFile *createTLOF(X86TargetMachine &TM) {
       return new X8664_MachoTargetObjectFile();
     return new X8632_MachoTargetObjectFile();
   case X86Subtarget::isELF:
-    return new TargetLoweringObjectFileELF();
+   if (TM.getSubtarget<X86Subtarget>().is64Bit())
+     return new X8664_ELFTargetObjectFile(TM);
+    return new X8632_ELFTargetObjectFile(TM);
   case X86Subtarget::isMingw:
   case X86Subtarget::isCygwin:
   case X86Subtarget::isWindows:
     return new TargetLoweringObjectFileCOFF();
   }
-
 }
 
 X86TargetLowering::X86TargetLowering(X86TargetMachine &TM)
diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp
index b507871..7802f98 100644
--- a/lib/Target/X86/X86TargetMachine.cpp
+++ b/lib/Target/X86/X86TargetMachine.cpp
@@ -199,32 +199,3 @@ void X86TargetMachine::setCodeModelForJIT() {
   else
     setCodeModel(CodeModel::Small);
 }
-
-/// getLSDAEncoding - Returns the LSDA pointer encoding. The choices are 4-byte,
-/// 8-byte, and target default. The CIE is hard-coded to indicate that the LSDA
-/// pointer in the FDE section is an "sdata4", and should be encoded as a 4-byte
-/// pointer by default. However, some systems may require a different size due
-/// to bugs or other conditions. We will default to a 4-byte encoding unless the
-/// system tells us otherwise.
-///
-/// The issue is when the CIE says their is an LSDA. That mandates that every
-/// FDE have an LSDA slot. But if the function does not need an LSDA. There
-/// needs to be some way to signify there is none. The LSDA is encoded as
-/// pc-rel. But you don't look for some magic value after adding the pc. You
-/// have to look for a zero before adding the pc. The problem is that the size
-/// of the zero to look for depends on the encoding. The unwinder bug in SL is
-/// that it always checks for a pointer-size zero. So on x86_64 it looks for 8
-/// bytes of zero. If you have an LSDA, it works fine since the 8-bytes are
-/// non-zero so it goes ahead and then reads the value based on the encoding.
-/// But if you use sdata4 and there is no LSDA, then the test for zero gives a
-/// false negative and the unwinder thinks there is an LSDA.
-///
-/// FIXME: This call-back isn't good! We should be using the correct encoding
-/// regardless of the system. However, there are some systems which have bugs
-/// that prevent this from occuring.
-DwarfLSDAEncoding::Encoding X86TargetMachine::getLSDAEncoding() const {
-  if (Subtarget.isTargetDarwin() && Subtarget.getDarwinVers() != 10)
-    return DwarfLSDAEncoding::Default;
-
-  return DwarfLSDAEncoding::EightByte;
-}
diff --git a/lib/Target/X86/X86TargetMachine.h b/lib/Target/X86/X86TargetMachine.h
index eee29be..2bb5454 100644
--- a/lib/Target/X86/X86TargetMachine.h
+++ b/lib/Target/X86/X86TargetMachine.h
@@ -62,18 +62,6 @@ public:
     return Subtarget.isTargetELF() ? &ELFWriterInfo : 0;
   }
 
-  /// getLSDAEncoding - Returns the LSDA pointer encoding. The choices are
-  /// 4-byte, 8-byte, and target default. The CIE is hard-coded to indicate that
-  /// the LSDA pointer in the FDE section is an "sdata4", and should be encoded
-  /// as a 4-byte pointer by default. However, some systems may require a
-  /// different size due to bugs or other conditions. We will default to a
-  /// 4-byte encoding unless the system tells us otherwise.
-  ///
-  /// FIXME: This call-back isn't good! We should be using the correct encoding
-  /// regardless of the system. However, there are some systems which have bugs
-  /// that prevent this from occuring.
-  virtual DwarfLSDAEncoding::Encoding getLSDAEncoding() const;
-
   // Set up the pass pipeline.
   virtual bool addInstSelector(PassManagerBase &PM, CodeGenOpt::Level OptLevel);
   virtual bool addPreRegAlloc(PassManagerBase &PM, CodeGenOpt::Level OptLevel);
diff --git a/lib/Target/X86/X86TargetObjectFile.cpp b/lib/Target/X86/X86TargetObjectFile.cpp
index b8cef7d..be01b5f 100644
--- a/lib/Target/X86/X86TargetObjectFile.cpp
+++ b/lib/Target/X86/X86TargetObjectFile.cpp
@@ -7,61 +7,177 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "X86TargetObjectFile.h"
 #include "X86MCTargetExpr.h"
+#include "X86TargetObjectFile.h"
+#include "X86TargetMachine.h"
 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/Target/Mangler.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Dwarf.h"
 using namespace llvm;
+using namespace dwarf;
 
 const MCExpr *X8632_MachoTargetObjectFile::
 getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
-                                 MachineModuleInfo *MMI,
-                                 bool &IsIndirect, bool &IsPCRel) const {
+                             MachineModuleInfo *MMI, unsigned Encoding) const {
   // The mach-o version of this method defaults to returning a stub reference.
-  IsIndirect = true;
-  IsPCRel    = false;
-  
-  
-  MachineModuleInfoMachO &MachOMMI =
-  MMI->getObjFileInfo<MachineModuleInfoMachO>();
-  
-  // FIXME: Use GetSymbolWithGlobalValueBase.
-  SmallString<128> Name;
-  Mang->getNameWithPrefix(Name, GV, true);
-  Name += "$non_lazy_ptr";
-  
-  // Add information about the stub reference to MachOMMI so that the stub gets
-  // emitted by the asmprinter.
-  MCSymbol *Sym = getContext().GetOrCreateSymbol(Name.str());
-  MCSymbol *&StubSym = MachOMMI.getGVStubEntry(Sym);
-  if (StubSym == 0) {
-    Name.clear();
-    Mang->getNameWithPrefix(Name, GV, false);
-    StubSym = getContext().GetOrCreateSymbol(Name.str());
+
+  if (Encoding & DW_EH_PE_indirect) {
+    MachineModuleInfoMachO &MachOMMI =
+      MMI->getObjFileInfo<MachineModuleInfoMachO>();
+
+    SmallString<128> Name;
+    Mang->getNameWithPrefix(Name, GV, true);
+    Name += "$non_lazy_ptr";
+
+    // Add information about the stub reference to MachOMMI so that the stub
+    // gets emitted by the asmprinter.
+    MCSymbol *Sym = getContext().GetOrCreateSymbol(Name.str());
+    MCSymbol *&StubSym = MachOMMI.getGVStubEntry(Sym);
+    if (StubSym == 0) {
+      Name.clear();
+      Mang->getNameWithPrefix(Name, GV, false);
+      StubSym = getContext().GetOrCreateSymbol(Name.str());
+    }
+
+    return TargetLoweringObjectFile::
+      getSymbolForDwarfReference(Sym, MMI,
+                                 Encoding & ~dwarf::DW_EH_PE_indirect);
   }
-  
-  return MCSymbolRefExpr::Create(Sym, getContext());
+
+  return TargetLoweringObjectFileMachO::
+    getSymbolForDwarfGlobalReference(GV, Mang, MMI, Encoding);
 }
 
 const MCExpr *X8664_MachoTargetObjectFile::
 getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
-                                 MachineModuleInfo *MMI,
-                                 bool &IsIndirect, bool &IsPCRel) const {
-  
+                           MachineModuleInfo *MMI, unsigned Encoding) const {
+
   // On Darwin/X86-64, we can reference dwarf symbols with foo@GOTPCREL+4, which
   // is an indirect pc-relative reference.
-  IsIndirect = true;
-  IsPCRel    = true;
-  
-  // FIXME: Use GetSymbolWithGlobalValueBase.
-  SmallString<128> Name;
-  Mang->getNameWithPrefix(Name, GV, false);
+  if ((Encoding & DW_EH_PE_indirect) &&
+      (Encoding & DW_EH_PE_pcrel)) {
+    SmallString<128> Name;
+    Mang->getNameWithPrefix(Name, GV, false);
   const MCSymbol *Sym = getContext().CreateSymbol(Name);
   const MCExpr *Res =
     X86MCTargetExpr::Create(Sym, X86MCTargetExpr::GOTPCREL, getContext());
   const MCExpr *Four = MCConstantExpr::Create(4, getContext());
   return MCBinaryExpr::CreateAdd(Res, Four, getContext());
+  }
+
+  return TargetLoweringObjectFileMachO::
+    getSymbolForDwarfGlobalReference(GV, Mang, MMI, Encoding);
+}
+
+unsigned X8632_ELFTargetObjectFile::getPersonalityEncoding() const {
+  if (TM.getRelocationModel() == Reloc::PIC_)
+    return DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+  else
+    return DW_EH_PE_absptr;
+}
+
+unsigned X8632_ELFTargetObjectFile::getLSDAEncoding() const {
+  if (TM.getRelocationModel() == Reloc::PIC_)
+    return DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+  else
+    return DW_EH_PE_absptr;
+}
+
+unsigned X8632_ELFTargetObjectFile::getFDEEncoding() const {
+  if (TM.getRelocationModel() == Reloc::PIC_)
+    return DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+  else
+    return DW_EH_PE_absptr;
+}
+
+unsigned X8632_ELFTargetObjectFile::getTTypeEncoding() const {
+  if (TM.getRelocationModel() == Reloc::PIC_)
+    return DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+  else
+    return DW_EH_PE_absptr;
 }
 
+unsigned X8664_ELFTargetObjectFile::getPersonalityEncoding() const {
+  CodeModel::Model Model = TM.getCodeModel();
+  if (TM.getRelocationModel() == Reloc::PIC_)
+    return DW_EH_PE_indirect | DW_EH_PE_pcrel | (Model == CodeModel::Small ||
+                                                 Model == CodeModel::Medium ?
+                                            DW_EH_PE_sdata4 : DW_EH_PE_sdata8);
+
+  if (Model == CodeModel::Small || Model == CodeModel::Medium)
+    return DW_EH_PE_udata4;
+
+  return DW_EH_PE_absptr;
+}
+
+unsigned X8664_ELFTargetObjectFile::getLSDAEncoding() const {
+  CodeModel::Model Model = TM.getCodeModel();
+  if (TM.getRelocationModel() == Reloc::PIC_)
+    return DW_EH_PE_pcrel | (Model == CodeModel::Small ?
+                             DW_EH_PE_sdata4 : DW_EH_PE_sdata8);
+
+  if (Model == CodeModel::Small)
+    return DW_EH_PE_udata4;
+
+  return DW_EH_PE_absptr;
+}
+
+unsigned X8664_ELFTargetObjectFile::getFDEEncoding() const {
+  CodeModel::Model Model = TM.getCodeModel();
+  if (TM.getRelocationModel() == Reloc::PIC_)
+    return DW_EH_PE_pcrel | (Model == CodeModel::Small ||
+                             Model == CodeModel::Medium ?
+                             DW_EH_PE_sdata4 : DW_EH_PE_sdata8);
+
+  if (Model == CodeModel::Small || Model == CodeModel::Medium)
+    return DW_EH_PE_udata4;
+
+  return DW_EH_PE_absptr;
+}
+
+unsigned X8664_ELFTargetObjectFile::getTTypeEncoding() const {
+  CodeModel::Model Model = TM.getCodeModel();
+  if (TM.getRelocationModel() == Reloc::PIC_)
+    return DW_EH_PE_indirect | DW_EH_PE_pcrel | (Model == CodeModel::Small ||
+                                                 Model == CodeModel::Medium ?
+                                            DW_EH_PE_sdata4 : DW_EH_PE_sdata8);
+
+  if (Model == CodeModel::Small)
+    return DW_EH_PE_udata4;
+
+  return DW_EH_PE_absptr;
+}
+
+unsigned X8632_MachoTargetObjectFile::getPersonalityEncoding() const {
+  return DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+}
+
+unsigned X8632_MachoTargetObjectFile::getLSDAEncoding() const {
+  return DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+}
+
+unsigned X8632_MachoTargetObjectFile::getFDEEncoding() const {
+  return DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+}
+
+unsigned X8632_MachoTargetObjectFile::getTTypeEncoding() const {
+  return DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+}
+
+unsigned X8664_MachoTargetObjectFile::getPersonalityEncoding() const {
+  return DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+}
+
+unsigned X8664_MachoTargetObjectFile::getLSDAEncoding() const {
+  return DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+}
+
+unsigned X8664_MachoTargetObjectFile::getFDEEncoding() const {
+  return DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+}
+
+unsigned X8664_MachoTargetObjectFile::getTTypeEncoding() const {
+  return DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+}
diff --git a/lib/Target/X86/X86TargetObjectFile.h b/lib/Target/X86/X86TargetObjectFile.h
index 377a93b..0b5dec1 100644
--- a/lib/Target/X86/X86TargetObjectFile.h
+++ b/lib/Target/X86/X86TargetObjectFile.h
@@ -10,21 +10,26 @@
 #ifndef LLVM_TARGET_X86_TARGETOBJECTFILE_H
 #define LLVM_TARGET_X86_TARGETOBJECTFILE_H
 
+#include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
 
 namespace llvm {
-  
+  class X86TargetMachine;
+
   /// X8632_MachoTargetObjectFile - This TLOF implementation is used for
   /// Darwin/x86-32.
   class X8632_MachoTargetObjectFile : public TargetLoweringObjectFileMachO {
   public:
-    
+
     virtual const MCExpr *
     getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
-                                     MachineModuleInfo *MMI,
-                                     bool &IsIndirect, bool &IsPCRel) const;
+                              MachineModuleInfo *MMI, unsigned Encoding) const;
+    virtual unsigned getPersonalityEncoding() const;
+    virtual unsigned getLSDAEncoding() const;
+    virtual unsigned getFDEEncoding() const;
+    virtual unsigned getTTypeEncoding() const;
   };
-  
+
   /// X8664_MachoTargetObjectFile - This TLOF implementation is used for
   /// Darwin/x86-64.
   class X8664_MachoTargetObjectFile : public TargetLoweringObjectFileMachO {
@@ -32,9 +37,35 @@ namespace llvm {
 
     virtual const MCExpr *
     getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
-                                     MachineModuleInfo *MMI,
-                                     bool &IsIndirect, bool &IsPCRel) const;
+                              MachineModuleInfo *MMI, unsigned Encoding) const;
+    virtual unsigned getPersonalityEncoding() const;
+    virtual unsigned getLSDAEncoding() const;
+    virtual unsigned getFDEEncoding() const;
+    virtual unsigned getTTypeEncoding() const;
+  };
+
+  class X8632_ELFTargetObjectFile : public TargetLoweringObjectFileELF {
+    const X86TargetMachine &TM;
+  public:
+    X8632_ELFTargetObjectFile(const X86TargetMachine &tm)
+      :TM(tm) { };
+    virtual unsigned getPersonalityEncoding() const;
+    virtual unsigned getLSDAEncoding() const;
+    virtual unsigned getFDEEncoding() const;
+    virtual unsigned getTTypeEncoding() const;
   };
+
+  class X8664_ELFTargetObjectFile : public TargetLoweringObjectFileELF {
+    const X86TargetMachine &TM;
+  public:
+    X8664_ELFTargetObjectFile(const X86TargetMachine &tm)
+      :TM(tm) { };
+    virtual unsigned getPersonalityEncoding() const;
+    virtual unsigned getLSDAEncoding() const;
+    virtual unsigned getFDEEncoding() const;
+    virtual unsigned getTTypeEncoding() const;
+  };
+
 } // end namespace llvm
 
 #endif