Add CFI directives-based frame information emission. Not hooked yet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123474 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/AsmPrinter.h

@@ -389,7 +389,7 @@ namespace llvm {
     /// frame.
     void EmitFrameMoves(const std::vector<MachineMove> &Moves,
                         MCSymbol *BaseLabel, bool isEH) const;
-
+    void EmitCFIFrameMoves(const std::vector<MachineMove> &Moves) const;
 
     //===------------------------------------------------------------------===//
     // Inline Asm Support

lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp

@@ -276,3 +276,43 @@ void AsmPrinter::EmitFrameMoves(const std::vector<MachineMove> &Moves,
     }
   }
 }
+
+/// EmitFrameMoves - Emit frame instructions to describe the layout of the
+/// frame.
+void AsmPrinter::EmitCFIFrameMoves(const std::vector<MachineMove> &Moves) const {
+  const TargetRegisterInfo *RI = TM.getRegisterInfo();
+
+  int stackGrowth = TM.getTargetData()->getPointerSize();
+  if (TM.getFrameLowering()->getStackGrowthDirection() !=
+      TargetFrameLowering::StackGrowsUp)
+    stackGrowth *= -1;
+
+  for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
+    const MachineMove &Move = Moves[i];
+    MCSymbol *Label = Move.getLabel();
+    // Throw out move if the label is invalid.
+    if (Label && !Label->isDefined()) continue; // Not emitted, in dead code.
+
+    const MachineLocation &Dst = Move.getDestination();
+    const MachineLocation &Src = Move.getSource();
+
+    // If advancing cfa.
+    if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) {
+      assert(!Src.isReg() && "Machine move not supported yet.");
+
+      if (Src.getReg() == MachineLocation::VirtualFP) {
+        OutStreamer.EmitCFIDefCfaOffset(-Src.getOffset());
+      } else {
+        assert("Machine move not supported yet");
+        // Reg + Offset
+      }
+    } else if (Src.isReg() && Src.getReg() == MachineLocation::VirtualFP) {
+      assert(Dst.isReg() && "Machine move not supported yet.");
+      OutStreamer.EmitCFIDefCfaRegister(RI->getDwarfRegNum(Dst.getReg(), true));
+    } else {
+      assert(!Dst.isReg() && "Machine move not supported yet.");
+      OutStreamer.EmitCFIOffset(RI->getDwarfRegNum(Src.getReg(), true),
+                                Dst.getOffset());
+    }
+  }
+}

lib/CodeGen/AsmPrinter/DwarfCFIException.cpp

@@ -0,0 +1,138 @@
+//===-- CodeGen/AsmPrinter/DwarfException.cpp - Dwarf 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;
+
+DwarfCFIException::DwarfCFIException(AsmPrinter *A)
+  : DwarfException(A),
+    shouldEmitTable(false), shouldEmitMoves(false), shouldEmitTableModule(false)
+    {}
+
+DwarfCFIException::~DwarfCFIException() {}
+
+/// EndModule - Emit all exception information that should come after the
+/// content.
+void DwarfCFIException::EndModule() {
+  if (Asm->MAI->getExceptionHandlingType() != ExceptionHandling::Dwarf)
+    return;
+
+  if (!shouldEmitTableModule)
+    return;
+
+  const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
+  unsigned PerEncoding = TLOF.getPersonalityEncoding();
+
+  // Begin eh frame section.
+  Asm->OutStreamer.SwitchSection(TLOF.getEHFrameSection());
+
+  // Emit references to all used personality functions
+  const std::vector<const Function*> &Personalities = MMI->getPersonalities();
+  for (size_t i = 0, e = Personalities.size(); i != e; ++i) {
+    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("personality", i));
+    Asm->EmitReference(Personalities[i], PerEncoding);
+  }
+}
+
+/// BeginFunction - Gather pre-function exception information. Assumes it's
+/// being emitted immediately after the function entry point.
+void DwarfCFIException::BeginFunction(const MachineFunction *MF) {
+  shouldEmitTable = shouldEmitMoves = false;
+
+  // If any landing pads survive, we need an EH table.
+  shouldEmitTable = !MMI->getLandingPads().empty();
+
+  // See if we need frame move info.
+  shouldEmitMoves =
+    !Asm->MF->getFunction()->doesNotThrow() || UnwindTablesMandatory;
+
+  if (shouldEmitMoves || shouldEmitTable)
+    // Assumes in correct section after the entry point.
+    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
+                                                  Asm->getFunctionNumber()));
+
+  shouldEmitTableModule |= shouldEmitTable;
+
+  if (shouldEmitMoves) {
+    const TargetFrameLowering *TFL = Asm->TM.getFrameLowering();
+    Asm->OutStreamer.EmitCFIStartProc();
+
+    // Indicate locations of general callee saved registers in frame.
+    std::vector<MachineMove> Moves;
+    TFL->getInitialFrameState(Moves);
+    Asm->EmitCFIFrameMoves(Moves);
+    Asm->EmitCFIFrameMoves(MMI->getFrameMoves());
+  }
+
+  if (!shouldEmitTable)
+    return;
+
+  const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
+
+  // Provide LSDA information.
+  unsigned LSDAEncoding = TLOF.getLSDAEncoding();
+  if (LSDAEncoding != dwarf::DW_EH_PE_omit)
+    Asm->OutStreamer.EmitCFILsda(Asm->GetTempSymbol("exception",
+                                                    Asm->getFunctionNumber()),
+                                 LSDAEncoding);
+
+  // Indicate personality routine, if any.
+  unsigned PerEncoding = TLOF.getPersonalityEncoding();
+  if (PerEncoding != dwarf::DW_EH_PE_omit &&
+      MMI->getPersonalities()[MMI->getPersonalityIndex()])
+    Asm->OutStreamer.EmitCFIPersonality(Asm->GetTempSymbol("personality",
+                                                    MMI->getPersonalityIndex()),
+                                        PerEncoding);
+}
+
+/// EndFunction - Gather and emit post-function exception information.
+///
+void DwarfCFIException::EndFunction() {
+  if (!shouldEmitMoves && !shouldEmitTable) return;
+
+  if (shouldEmitMoves)
+    Asm->OutStreamer.EmitCFIEndProc();
+
+  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
+                                                Asm->getFunctionNumber()));
+
+  // Map all labels and get rid of any dead landing pads.
+  MMI->TidyLandingPads();
+
+  if (shouldEmitTable)
+    EmitExceptionTable();
+}

lib/CodeGen/AsmPrinter/DwarfException.h

@@ -139,6 +139,37 @@ class DwarfException {
   virtual void EndFunction();
 };
 
+class DwarfCFIException : 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.
+  //
+  DwarfCFIException(AsmPrinter *A);
+  virtual ~DwarfCFIException();
+
+  /// 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();
+};
+
 class DwarfTableException : public DwarfException {
   /// shouldEmitTable - Per-function flag to indicate if EH tables should
   /// be emitted.