1 files changed, 156 insertions, 0 deletions
diff --git a/lib/CodeGen/AsmPrinter/DwarfFile.cpp b/lib/CodeGen/AsmPrinter/DwarfFile.cpp
new file mode 100644
index 0000000..737ee54
--- /dev/null
+++ b/lib/CodeGen/AsmPrinter/DwarfFile.cpp
@@ -0,0 +1,156 @@
+//===-- 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, StringRef Pref, BumpPtrAllocator &DA)
+    : Asm(AP), StrPool(DA, *Asm, Pref) {}
+
+DwarfFile::~DwarfFile() {}
+
+// 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) {
+  StrPool.emit(*Asm, StrSection, OffsetSection, StrSecSym);
+}
+}