Split out DwarfFile from DwarfDebug into its own .h/.cpp files.

Some of these types (DwarfDebug in particular) are quite large to begin
with (and I keep forgetting whether DwarfFile is in DwarfDebug or
DwarfUnit... ) so having a few smaller files seems like goodness.

llvm-svn: 207010

1 files changed, 244 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
new file mode 100644
index 00000000000..04b4b94b262
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
@@ -0,0 +1,244 @@
+//===-- llvm/CodeGen/DwarfFile.cpp - Dwarf Debug Framework ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DwarfFile.h"
+
+#include "DwarfDebug.h"
+#include "DwarfUnit.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/Support/LEB128.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
+
+namespace llvm {
+DwarfFile::DwarfFile(AsmPrinter *AP, const char *Pref, BumpPtrAllocator &DA)
+    : Asm(AP), StringPool(DA), NextStringPoolNumber(0), StringPref(Pref) {}
+
+DwarfFile::~DwarfFile() {
+}
+
+MCSymbol *DwarfFile::getStringPoolSym() {
+  return Asm->GetTempSymbol(StringPref);
+}
+
+MCSymbol *DwarfFile::getStringPoolEntry(StringRef Str) {
+  std::pair<MCSymbol *, unsigned> &Entry =
+      StringPool.GetOrCreateValue(Str).getValue();
+  if (Entry.first)
+    return Entry.first;
+
+  Entry.second = NextStringPoolNumber++;
+  return Entry.first = Asm->GetTempSymbol(StringPref, Entry.second);
+}
+
+unsigned DwarfFile::getStringPoolIndex(StringRef Str) {
+  std::pair<MCSymbol *, unsigned> &Entry =
+      StringPool.GetOrCreateValue(Str).getValue();
+  if (Entry.first)
+    return Entry.second;
+
+  Entry.second = NextStringPoolNumber++;
+  Entry.first = Asm->GetTempSymbol(StringPref, Entry.second);
+  return Entry.second;
+}
+
+unsigned DwarfFile::getAddrPoolIndex(const MCSymbol *Sym, bool TLS) {
+  std::pair<AddrPool::iterator, bool> P = AddressPool.insert(
+      std::make_pair(Sym, AddressPoolEntry(AddressPool.size(), TLS)));
+  return P.first->second.Number;
+}
+
+// Define a unique number for the abbreviation.
+//
+void DwarfFile::assignAbbrevNumber(DIEAbbrev &Abbrev) {
+  // Check the set for priors.
+  DIEAbbrev *InSet = AbbreviationsSet.GetOrInsertNode(&Abbrev);
+
+  // If it's newly added.
+  if (InSet == &Abbrev) {
+    // Add to abbreviation list.
+    Abbreviations.push_back(&Abbrev);
+
+    // Assign the vector position + 1 as its number.
+    Abbrev.setNumber(Abbreviations.size());
+  } else {
+    // Assign existing abbreviation number.
+    Abbrev.setNumber(InSet->getNumber());
+  }
+}
+
+void DwarfFile::addUnit(std::unique_ptr<DwarfUnit> U) {
+  CUs.push_back(std::move(U));
+}
+
+// Emit the various dwarf units to the unit section USection with
+// the abbreviations going into ASection.
+void DwarfFile::emitUnits(DwarfDebug *DD, const MCSymbol *ASectionSym) {
+  for (const auto &TheU : CUs) {
+    DIE *Die = TheU->getUnitDie();
+    const MCSection *USection = TheU->getSection();
+    Asm->OutStreamer.SwitchSection(USection);
+
+    // Emit the compile units header.
+    Asm->OutStreamer.EmitLabel(TheU->getLabelBegin());
+
+    // Emit size of content not including length itself
+    Asm->OutStreamer.AddComment("Length of Unit");
+    Asm->EmitInt32(TheU->getHeaderSize() + Die->getSize());
+
+    TheU->emitHeader(ASectionSym);
+
+    DD->emitDIE(*Die);
+    Asm->OutStreamer.EmitLabel(TheU->getLabelEnd());
+  }
+}
+// Compute the size and offset for each DIE.
+void DwarfFile::computeSizeAndOffsets() {
+  // Offset from the first CU in the debug info section is 0 initially.
+  unsigned SecOffset = 0;
+
+  // Iterate over each compile unit and set the size and offsets for each
+  // DIE within each compile unit. All offsets are CU relative.
+  for (const auto &TheU : CUs) {
+    TheU->setDebugInfoOffset(SecOffset);
+
+    // CU-relative offset is reset to 0 here.
+    unsigned Offset = sizeof(int32_t) +      // Length of Unit Info
+                      TheU->getHeaderSize(); // Unit-specific headers
+
+    // EndOffset here is CU-relative, after laying out
+    // all of the CU DIE.
+    unsigned EndOffset = computeSizeAndOffset(*TheU->getUnitDie(), Offset);
+    SecOffset += EndOffset;
+  }
+}
+// Compute the size and offset of a DIE. The offset is relative to start of the
+// CU. It returns the offset after laying out the DIE.
+unsigned DwarfFile::computeSizeAndOffset(DIE &Die, unsigned Offset) {
+  // Record the abbreviation.
+  assignAbbrevNumber(Die.getAbbrev());
+
+  // Get the abbreviation for this DIE.
+  const DIEAbbrev &Abbrev = Die.getAbbrev();
+
+  // Set DIE offset
+  Die.setOffset(Offset);
+
+  // Start the size with the size of abbreviation code.
+  Offset += getULEB128Size(Die.getAbbrevNumber());
+
+  const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
+  const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
+
+  // Size the DIE attribute values.
+  for (unsigned i = 0, N = Values.size(); i < N; ++i)
+    // Size attribute value.
+    Offset += Values[i]->SizeOf(Asm, AbbrevData[i].getForm());
+
+  // Get the children.
+  const auto &Children = Die.getChildren();
+
+  // Size the DIE children if any.
+  if (!Children.empty()) {
+    assert(Abbrev.hasChildren() && "Children flag not set");
+
+    for (auto &Child : Children)
+      Offset = computeSizeAndOffset(*Child, Offset);
+
+    // End of children marker.
+    Offset += sizeof(int8_t);
+  }
+
+  Die.setSize(Offset - Die.getOffset());
+  return Offset;
+}
+void DwarfFile::emitAbbrevs(const MCSection *Section) {
+  // Check to see if it is worth the effort.
+  if (!Abbreviations.empty()) {
+    // Start the debug abbrev section.
+    Asm->OutStreamer.SwitchSection(Section);
+
+    // For each abbrevation.
+    for (const DIEAbbrev *Abbrev : Abbreviations) {
+      // Emit the abbrevations code (base 1 index.)
+      Asm->EmitULEB128(Abbrev->getNumber(), "Abbreviation Code");
+
+      // Emit the abbreviations data.
+      Abbrev->Emit(Asm);
+    }
+
+    // Mark end of abbreviations.
+    Asm->EmitULEB128(0, "EOM(3)");
+  }
+}
+
+// Emit strings into a string section.
+void DwarfFile::emitStrings(const MCSection *StrSection,
+                            const MCSection *OffsetSection,
+                            const MCSymbol *StrSecSym) {
+
+  if (StringPool.empty())
+    return;
+
+  // Start the dwarf str section.
+  Asm->OutStreamer.SwitchSection(StrSection);
+
+  // Get all of the string pool entries and put them in an array by their ID so
+  // we can sort them.
+  SmallVector<std::pair<unsigned, const StrPool::value_type *>, 64 > Entries;
+
+  for (const auto &I : StringPool)
+    Entries.push_back(std::make_pair(I.second.second, &I));
+
+  array_pod_sort(Entries.begin(), Entries.end());
+
+  for (const auto &Entry : Entries) {
+    // Emit a label for reference from debug information entries.
+    Asm->OutStreamer.EmitLabel(Entry.second->getValue().first);
+
+    // Emit the string itself with a terminating null byte.
+    Asm->OutStreamer.EmitBytes(StringRef(Entry.second->getKeyData(),
+                                         Entry.second->getKeyLength() + 1));
+  }
+
+  // If we've got an offset section go ahead and emit that now as well.
+  if (OffsetSection) {
+    Asm->OutStreamer.SwitchSection(OffsetSection);
+    unsigned offset = 0;
+    unsigned size = 4; // FIXME: DWARF64 is 8.
+    for (const auto &Entry : Entries) {
+      Asm->OutStreamer.EmitIntValue(offset, size);
+      offset += Entry.second->getKeyLength() + 1;
+    }
+  }
+}
+
+// Emit addresses into the section given.
+void DwarfFile::emitAddresses(const MCSection *AddrSection) {
+
+  if (AddressPool.empty())
+    return;
+
+  // Start the dwarf addr section.
+  Asm->OutStreamer.SwitchSection(AddrSection);
+
+  // Order the address pool entries by ID
+  SmallVector<const MCExpr *, 64> Entries(AddressPool.size());
+
+  for (const auto &I : AddressPool)
+    Entries[I.second.Number] =
+        I.second.TLS
+            ? Asm->getObjFileLowering().getDebugThreadLocalSymbol(I.first)
+            : MCSymbolRefExpr::Create(I.first, Asm->OutContext);
+
+  for (const MCExpr *Entry : Entries)
+    Asm->OutStreamer.EmitValue(Entry, Asm->getDataLayout().getPointerSize());
+}
+}