diff lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp @ 0:95c75e76d11b

LLVM 3.4
author Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
date Thu, 12 Dec 2013 13:56:28 +0900
parents
children e4204d083e25
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp	Thu Dec 12 13:56:28 2013 +0900
@@ -0,0 +1,195 @@
+//===-- AsmPrinterDwarf.cpp - AsmPrinter Dwarf Support --------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Dwarf emissions parts of AsmPrinter.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "asm-printer"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MachineLocation.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Target/TargetFrameLowering.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Dwarf Emission Helper Routines
+//===----------------------------------------------------------------------===//
+
+/// EmitSLEB128 - emit the specified signed leb128 value.
+void AsmPrinter::EmitSLEB128(int64_t Value, const char *Desc) const {
+  if (isVerbose() && Desc)
+    OutStreamer.AddComment(Desc);
+
+  OutStreamer.EmitSLEB128IntValue(Value);
+}
+
+/// EmitULEB128 - emit the specified signed leb128 value.
+void AsmPrinter::EmitULEB128(uint64_t Value, const char *Desc,
+                             unsigned PadTo) const {
+  if (isVerbose() && Desc)
+    OutStreamer.AddComment(Desc);
+
+  OutStreamer.EmitULEB128IntValue(Value, PadTo);
+}
+
+/// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value.
+void AsmPrinter::EmitCFAByte(unsigned Val) const {
+  if (isVerbose()) {
+    if (Val >= dwarf::DW_CFA_offset && Val < dwarf::DW_CFA_offset+64)
+      OutStreamer.AddComment("DW_CFA_offset + Reg (" +
+                             Twine(Val-dwarf::DW_CFA_offset) + ")");
+    else
+      OutStreamer.AddComment(dwarf::CallFrameString(Val));
+  }
+  OutStreamer.EmitIntValue(Val, 1);
+}
+
+static const char *DecodeDWARFEncoding(unsigned Encoding) {
+  switch (Encoding) {
+  case dwarf::DW_EH_PE_absptr: return "absptr";
+  case dwarf::DW_EH_PE_omit:   return "omit";
+  case dwarf::DW_EH_PE_pcrel:  return "pcrel";
+  case dwarf::DW_EH_PE_udata4: return "udata4";
+  case dwarf::DW_EH_PE_udata8: return "udata8";
+  case dwarf::DW_EH_PE_sdata4: return "sdata4";
+  case dwarf::DW_EH_PE_sdata8: return "sdata8";
+  case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata4: return "pcrel udata4";
+  case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4: return "pcrel sdata4";
+  case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8: return "pcrel udata8";
+  case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8: return "pcrel sdata8";
+  case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_udata4:
+    return "indirect pcrel udata4";
+  case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_sdata4:
+    return "indirect pcrel sdata4";
+  case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_udata8:
+    return "indirect pcrel udata8";
+  case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_sdata8:
+    return "indirect pcrel sdata8";
+  }
+
+  return "<unknown encoding>";
+}
+
+
+/// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an
+/// encoding.  If verbose assembly output is enabled, we output comments
+/// describing the encoding.  Desc is an optional string saying what the
+/// encoding is specifying (e.g. "LSDA").
+void AsmPrinter::EmitEncodingByte(unsigned Val, const char *Desc) const {
+  if (isVerbose()) {
+    if (Desc != 0)
+      OutStreamer.AddComment(Twine(Desc)+" Encoding = " +
+                             Twine(DecodeDWARFEncoding(Val)));
+    else
+      OutStreamer.AddComment(Twine("Encoding = ") +
+                             DecodeDWARFEncoding(Val));
+  }
+
+  OutStreamer.EmitIntValue(Val, 1);
+}
+
+/// GetSizeOfEncodedValue - Return the size of the encoding in bytes.
+unsigned AsmPrinter::GetSizeOfEncodedValue(unsigned Encoding) const {
+  if (Encoding == dwarf::DW_EH_PE_omit)
+    return 0;
+
+  switch (Encoding & 0x07) {
+  default: llvm_unreachable("Invalid encoded value.");
+  case dwarf::DW_EH_PE_absptr: return TM.getDataLayout()->getPointerSize();
+  case dwarf::DW_EH_PE_udata2: return 2;
+  case dwarf::DW_EH_PE_udata4: return 4;
+  case dwarf::DW_EH_PE_udata8: return 8;
+  }
+}
+
+void AsmPrinter::EmitTTypeReference(const GlobalValue *GV,
+                                    unsigned Encoding) const {
+  if (GV) {
+    const TargetLoweringObjectFile &TLOF = getObjFileLowering();
+
+    const MCExpr *Exp =
+      TLOF.getTTypeGlobalReference(GV, Mang, MMI, Encoding, OutStreamer);
+    OutStreamer.EmitValue(Exp, GetSizeOfEncodedValue(Encoding));
+  } else
+    OutStreamer.EmitIntValue(0, GetSizeOfEncodedValue(Encoding));
+}
+
+/// EmitSectionOffset - Emit the 4-byte offset of Label from the start of its
+/// section.  This can be done with a special directive if the target supports
+/// it (e.g. cygwin) or by emitting it as an offset from a label at the start
+/// of the section.
+///
+/// SectionLabel is a temporary label emitted at the start of the section that
+/// Label lives in.
+void AsmPrinter::EmitSectionOffset(const MCSymbol *Label,
+                                   const MCSymbol *SectionLabel) const {
+  // On COFF targets, we have to emit the special .secrel32 directive.
+  if (MAI->needsDwarfSectionOffsetDirective()) {
+    OutStreamer.EmitCOFFSecRel32(Label);
+    return;
+  }
+
+  // Get the section that we're referring to, based on SectionLabel.
+  const MCSection &Section = SectionLabel->getSection();
+
+  // If Label has already been emitted, verify that it is in the same section as
+  // section label for sanity.
+  assert((!Label->isInSection() || &Label->getSection() == &Section) &&
+         "Section offset using wrong section base for label");
+
+  // If the section in question will end up with an address of 0 anyway, we can
+  // just emit an absolute reference to save a relocation.
+  if (Section.isBaseAddressKnownZero()) {
+    OutStreamer.EmitSymbolValue(Label, 4);
+    return;
+  }
+
+  // Otherwise, emit it as a label difference from the start of the section.
+  EmitLabelDifference(Label, SectionLabel, 4);
+}
+
+//===----------------------------------------------------------------------===//
+// Dwarf Lowering Routines
+//===----------------------------------------------------------------------===//
+
+void AsmPrinter::emitCFIInstruction(const MCCFIInstruction &Inst) const {
+  switch (Inst.getOperation()) {
+  default:
+    llvm_unreachable("Unexpected instruction");
+  case MCCFIInstruction::OpDefCfaOffset:
+    OutStreamer.EmitCFIDefCfaOffset(Inst.getOffset());
+    break;
+  case MCCFIInstruction::OpDefCfa:
+    OutStreamer.EmitCFIDefCfa(Inst.getRegister(), Inst.getOffset());
+    break;
+  case MCCFIInstruction::OpDefCfaRegister:
+    OutStreamer.EmitCFIDefCfaRegister(Inst.getRegister());
+    break;
+  case MCCFIInstruction::OpOffset:
+    OutStreamer.EmitCFIOffset(Inst.getRegister(), Inst.getOffset());
+    break;
+  case MCCFIInstruction::OpRegister:
+    OutStreamer.EmitCFIRegister(Inst.getRegister(), Inst.getRegister2());
+    break;
+  case MCCFIInstruction::OpWindowSave:
+    OutStreamer.EmitCFIWindowSave();
+    break;
+  }
+}