Some first rudimentary support for ARM EHABI: print exception table in "text mode".

llvm-svn: 127099

include/llvm/MC/MCAsmInfo.h

@@ -26,7 +26,7 @@ namespace llvm {
   /// MCAsmInfo - This class is intended to be used as a base class for asm
   /// properties and features specific to the target.
   namespace ExceptionHandling {
-    enum ExceptionsType { None, DwarfTable, DwarfCFI, SjLj };
+    enum ExceptionsType { None, DwarfTable, DwarfCFI, SjLj, ARM };
   }
 
   class MCAsmInfo {
@@ -451,7 +451,8 @@ namespace llvm {
     bool isExceptionHandlingDwarf() const {
       return
         (ExceptionsType == ExceptionHandling::DwarfTable ||
-         ExceptionsType == ExceptionHandling::DwarfCFI);
+         ExceptionsType == ExceptionHandling::DwarfCFI ||
+         ExceptionsType == ExceptionHandling::ARM);
     }
 
     bool doesDwarfRequireFrameSection() const {

include/llvm/MC/MCStreamer.h

@@ -457,6 +457,15 @@ namespace llvm {
     virtual void EmitRawText(StringRef String);
     void EmitRawText(const Twine &String);
 
+    /// ARM-related methods.
+    /// FIXME: Eventually we should have some "target MC streamer" and move
+    /// these methods there.
+    virtual void EmitFnStart();
+    virtual void EmitFnEnd();
+    virtual void EmitCantUnwind();
+    virtual void EmitPersonality(const MCSymbol *Personality);
+    virtual void EmitHandlerData();
+
     /// Finish - Finish emission of machine code.
     virtual void Finish() = 0;
   };

lib/CodeGen/AsmPrinter/ARMException.cpp

@@ -0,0 +1,87 @@
+//===-- CodeGen/AsmPrinter/ARMException.cpp - ARM EHABI Exception Impl ----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for writing DWARF exception info into asm files.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DwarfException.h"
+#include "llvm/Module.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineLocation.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Target/Mangler.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetFrameLowering.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/FormattedStream.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/Twine.h"
+using namespace llvm;
+
+ARMException::ARMException(AsmPrinter *A)
+  : DwarfException(A),
+    shouldEmitTable(false), shouldEmitMoves(false), shouldEmitTableModule(false)
+    {}
+
+ARMException::~ARMException() {}
+
+void ARMException::EndModule() {
+}
+
+/// BeginFunction - Gather pre-function exception information. Assumes it's
+/// being emitted immediately after the function entry point.
+void ARMException::BeginFunction(const MachineFunction *MF) {
+  Asm->OutStreamer.EmitFnStart();
+  if (!Asm->MF->getFunction()->doesNotThrow() || UnwindTablesMandatory)
+    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
+                                                  Asm->getFunctionNumber()));
+}
+
+/// EndFunction - Gather and emit post-function exception information.
+///
+void ARMException::EndFunction() {
+  if (Asm->MF->getFunction()->doesNotThrow() && !UnwindTablesMandatory)
+    Asm->OutStreamer.EmitCantUnwind();
+  else {
+    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
+                                                  Asm->getFunctionNumber()));
+
+    // Emit references to personality.
+    if (const Function * Personality =
+        MMI->getPersonalities()[MMI->getPersonalityIndex()]) {
+      MCSymbol *PerSym = Asm->Mang->getSymbol(Personality);
+      Asm->OutStreamer.EmitSymbolAttribute(PerSym, MCSA_Global);
+      Asm->OutStreamer.EmitPersonality(PerSym);
+    }
+
+    // Map all labels and get rid of any dead landing pads.
+    MMI->TidyLandingPads();
+
+    Asm->OutStreamer.EmitHandlerData();
+
+    // Emit actual exception table
+    EmitExceptionTable();
+  }
+
+  Asm->OutStreamer.EmitFnEnd();
+}

lib/CodeGen/AsmPrinter/AsmPrinter.cpp

@@ -196,6 +196,9 @@ bool AsmPrinter::doInitialization(Module &M) {
     case ExceptionHandling::DwarfCFI:
       DE = new DwarfCFIException(this);
       break;
+    case ExceptionHandling::ARM:
+      DE = new ARMException(this);
+      break;
     }
 
   return false;

lib/CodeGen/AsmPrinter/DwarfException.h

@@ -237,6 +237,38 @@ public:
   virtual void EndFunction();
 };
 
+
+class ARMException : public DwarfException {
+  /// shouldEmitTable - Per-function flag to indicate if EH tables should
+  /// be emitted.
+  bool shouldEmitTable;
+
+  /// shouldEmitMoves - Per-function flag to indicate if frame moves info
+  /// should be emitted.
+  bool shouldEmitMoves;
+
+  /// shouldEmitTableModule - Per-module flag to indicate if EH tables
+  /// should be emitted.
+  bool shouldEmitTableModule;
+public:
+  //===--------------------------------------------------------------------===//
+  // Main entry points.
+  //
+  ARMException(AsmPrinter *A);
+  virtual ~ARMException();
+
+  /// EndModule - Emit all exception information that should come after the
+  /// content.
+  virtual void EndModule();
+
+  /// BeginFunction - Gather pre-function exception information.  Assumes being
+  /// emitted immediately after the function entry point.
+  virtual void BeginFunction(const MachineFunction *MF);
+
+  /// EndFunction - Gather and emit post-function exception information.
+  virtual void EndFunction();
+};
+
 } // End of namespace llvm
 
 #endif

lib/CodeGen/LLVMTargetMachine.cpp

@@ -292,6 +292,7 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM,
     // FALLTHROUGH
   case ExceptionHandling::DwarfCFI:
   case ExceptionHandling::DwarfTable:
+  case ExceptionHandling::ARM:
     PM.add(createDwarfEHPass(this));
     break;
   case ExceptionHandling::None:

lib/MC/MCAsmStreamer.cpp

@@ -192,6 +192,12 @@ public:
   virtual bool EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding);
   virtual bool EmitCFILsda(const MCSymbol *Sym, unsigned Encoding);
 
+  virtual void EmitFnStart();
+  virtual void EmitFnEnd();
+  virtual void EmitCantUnwind();
+  virtual void EmitPersonality(const MCSymbol *Personality);
+  virtual void EmitHandlerData();
+
   virtual void EmitInstruction(const MCInst &Inst);
 
   /// EmitRawText - If this file is backed by an assembly streamer, this dumps
@@ -859,6 +865,31 @@ void MCAsmStreamer::AddEncodingComment(const MCInst &Inst) {
   }
 }
 
+void MCAsmStreamer::EmitFnStart() {
+  OS << "\t.fnstart";
+  EmitEOL();
+}
+
+void MCAsmStreamer::EmitFnEnd() {
+  OS << "\t.fnend";
+  EmitEOL();
+}
+
+void MCAsmStreamer::EmitCantUnwind() {
+  OS << "\t.cantunwind";
+  EmitEOL();
+}
+
+void MCAsmStreamer::EmitHandlerData() {
+  OS << "\t.handlerdata";
+  EmitEOL();
+}
+
+void MCAsmStreamer::EmitPersonality(const MCSymbol *Personality) {
+  OS << "\t.personality " << Personality->getName();
+  EmitEOL();
+}
+
 void MCAsmStreamer::EmitInstruction(const MCInst &Inst) {
   assert(getCurrentSection() && "Cannot emit contents before setting section!");
 

lib/MC/MCStreamer.cpp

@@ -259,6 +259,31 @@ bool MCStreamer::EmitCFIRestoreState() {
   return false;
 }
 
+void MCStreamer::EmitFnStart() {
+  errs() << "Not implemented yet\n";
+  abort();
+}
+
+void MCStreamer::EmitFnEnd() {
+  errs() << "Not implemented yet\n";
+  abort();
+}
+
+void MCStreamer::EmitCantUnwind() {
+  errs() << "Not implemented yet\n";
+  abort();
+}
+
+void MCStreamer::EmitHandlerData() {
+  errs() << "Not implemented yet\n";
+  abort();
+}
+
+void MCStreamer::EmitPersonality(const MCSymbol *Personality) {
+  errs() << "Not implemented yet\n";
+  abort();
+}
+
 /// EmitRawText - If this file is backed by an assembly streamer, this dumps
 /// the specified string in the output .s file.  This capability is
 /// indicated by the hasRawTextSupport() predicate.

lib/Target/ARM/ARMMCAsmInfo.cpp

@@ -12,8 +12,16 @@
 //===----------------------------------------------------------------------===//
 
 #include "ARMMCAsmInfo.h"
+#include "llvm/Support/CommandLine.h"
+
 using namespace llvm;
 
+static cl::opt<bool>
+EnableARMEHABI("arm-enable-ehabi", cl::Hidden,
+  cl::desc("Generate ARM EHABI tables"),
+  cl::init(false));
+
+
 static const char *const arm_asm_table[] = {
   "{r0}", "r0",
   "{r1}", "r1",
@@ -65,4 +73,8 @@ ARMELFMCAsmInfo::ARMELFMCAsmInfo() {
   DwarfRequiresFrameSection = false;
 
   SupportsDebugInformation = true;
+
+  // Exceptions handling
+  if (EnableARMEHABI)
+    ExceptionsType = ExceptionHandling::ARM;
 }

lib/Target/ARM/ARMTargetObjectFile.cpp

@@ -36,8 +36,9 @@ void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
                                  ELF::SHF_WRITE |
                                  ELF::SHF_ALLOC,
                                  SectionKind::getDataRel());
+    LSDASection = NULL;
   }
-  
+
   AttributesSection =
     getContext().getELFSection(".ARM.attributes",
                                ELF::SHT_ARM_ATTRIBUTES,