X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;ds=sidebyside;f=lib%2FDebugInfo%2FDWARFContext.cpp;h=9f521330c34f4b3b25b3a15bbed79c7c15df6167;hb=6cfed36338d7728076ddbc1331908b887a4302d3;hp=3f9edd305b9624a5a77c7cba594b478f5b56811e;hpb=38a6381c0a58e013577b1957199128af9573fc20;p=oota-llvm.git

diff --git a/lib/DebugInfo/DWARFContext.cpp b/lib/DebugInfo/DWARFContext.cpp
index 3f9edd305b9..9f521330c34 100644
--- a/lib/DebugInfo/DWARFContext.cpp
+++ b/lib/DebugInfo/DWARFContext.cpp
@@ -9,6 +9,9 @@
 
 #include "DWARFContext.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/Compression.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/Path.h"
@@ -17,57 +20,133 @@
 using namespace llvm;
 using namespace dwarf;
 
-void DWARFContext::dump(raw_ostream &OS) {
-  OS << ".debug_abbrev contents:\n";
-  getDebugAbbrev()->dump(OS);
+typedef DWARFDebugLine::LineTable DWARFLineTable;
 
-  OS << "\n.debug_info contents:\n";
-  for (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i)
-    getCompileUnitAtIndex(i)->dump(OS);
+void DWARFContext::dump(raw_ostream &OS, DIDumpType DumpType) {
+  if (DumpType == DIDT_All || DumpType == DIDT_Abbrev) {
+    OS << ".debug_abbrev contents:\n";
+    getDebugAbbrev()->dump(OS);
+  }
+
+  if (DumpType == DIDT_All || DumpType == DIDT_Info) {
+    OS << "\n.debug_info contents:\n";
+    for (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i)
+      getCompileUnitAtIndex(i)->dump(OS);
+  }
+
+  if (DumpType == DIDT_All || DumpType == DIDT_Frames) {
+    OS << "\n.debug_frame contents:\n";
+    getDebugFrame()->dump(OS);
+  }
 
-  OS << "\n.debug_aranges contents:\n";
-  DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0);
   uint32_t offset = 0;
-  DWARFDebugArangeSet set;
-  while (set.extract(arangesData, &offset))
-    set.dump(OS);
+  if (DumpType == DIDT_All || DumpType == DIDT_Aranges) {
+    OS << "\n.debug_aranges contents:\n";
+    DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0);
+    DWARFDebugArangeSet set;
+    while (set.extract(arangesData, &offset))
+      set.dump(OS);
+  }
 
   uint8_t savedAddressByteSize = 0;
-  OS << "\n.debug_lines contents:\n";
-  for (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i) {
-    DWARFCompileUnit *cu = getCompileUnitAtIndex(i);
-    savedAddressByteSize = cu->getAddressByteSize();
-    unsigned stmtOffset =
-      cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list,
-                                                           -1U);
-    if (stmtOffset != -1U) {
-      DataExtractor lineData(getLineSection(), isLittleEndian(),
+  if (DumpType == DIDT_All || DumpType == DIDT_Line) {
+    OS << "\n.debug_line contents:\n";
+    for (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i) {
+      DWARFCompileUnit *cu = getCompileUnitAtIndex(i);
+      savedAddressByteSize = cu->getAddressByteSize();
+      unsigned stmtOffset =
+        cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list,
+                                                             -1U);
+      if (stmtOffset != -1U) {
+        DataExtractor lineData(getLineSection(), isLittleEndian(),
+                               savedAddressByteSize);
+        DWARFDebugLine::DumpingState state(OS);
+        DWARFDebugLine::parseStatementTable(lineData, &lineRelocMap(), &stmtOffset, state);
+      }
+    }
+  }
+
+  if (DumpType == DIDT_All || DumpType == DIDT_Str) {
+    OS << "\n.debug_str contents:\n";
+    DataExtractor strData(getStringSection(), isLittleEndian(), 0);
+    offset = 0;
+    uint32_t strOffset = 0;
+    while (const char *s = strData.getCStr(&offset)) {
+      OS << format("0x%8.8x: \"%s\"\n", strOffset, s);
+      strOffset = offset;
+    }
+  }
+
+  if (DumpType == DIDT_All || DumpType == DIDT_Ranges) {
+    OS << "\n.debug_ranges contents:\n";
+    // In fact, different compile units may have different address byte
+    // sizes, but for simplicity we just use the address byte size of the last
+    // compile unit (there is no easy and fast way to associate address range
+    // list and the compile unit it describes).
+    DataExtractor rangesData(getRangeSection(), isLittleEndian(),
                              savedAddressByteSize);
-      DWARFDebugLine::DumpingState state(OS);
-      DWARFDebugLine::parseStatementTable(lineData, &stmtOffset, state);
+    offset = 0;
+    DWARFDebugRangeList rangeList;
+    while (rangeList.extract(rangesData, &offset))
+      rangeList.dump(OS);
+  }
+
+  if (DumpType == DIDT_All || DumpType == DIDT_Pubnames) {
+    OS << "\n.debug_pubnames contents:\n";
+    DataExtractor pubNames(getPubNamesSection(), isLittleEndian(), 0);
+    offset = 0;
+    OS << "Length:                " << pubNames.getU32(&offset) << "\n";
+    OS << "Version:               " << pubNames.getU16(&offset) << "\n";
+    OS << "Offset in .debug_info: " << pubNames.getU32(&offset) << "\n";
+    OS << "Size:                  " << pubNames.getU32(&offset) << "\n";
+    OS << "\n  Offset    Name\n";
+    while (offset < getPubNamesSection().size()) {
+      uint32_t n = pubNames.getU32(&offset);
+      if (n == 0)
+        break;
+      OS << format("%8x    ", n);
+      OS << pubNames.getCStr(&offset) << "\n";
     }
   }
 
-  OS << "\n.debug_str contents:\n";
-  DataExtractor strData(getStringSection(), isLittleEndian(), 0);
-  offset = 0;
-  uint32_t lastOffset = 0;
-  while (const char *s = strData.getCStr(&offset)) {
-    OS << format("0x%8.8x: \"%s\"\n", lastOffset, s);
-    lastOffset = offset;
+  if (DumpType == DIDT_All || DumpType == DIDT_AbbrevDwo) {
+    const DWARFDebugAbbrev *D = getDebugAbbrevDWO();
+    if (D) {
+      OS << "\n.debug_abbrev.dwo contents:\n";
+      getDebugAbbrevDWO()->dump(OS);
+    }
   }
 
-  OS << "\n.debug_ranges contents:\n";
-  // In fact, different compile units may have different address byte
-  // sizes, but for simplicity we just use the address byte size of the last
-  // compile unit (there is no easy and fast way to associate address range
-  // list and the compile unit it describes).
-  DataExtractor rangesData(getRangeSection(), isLittleEndian(),
-                           savedAddressByteSize);
-  offset = 0;
-  DWARFDebugRangeList rangeList;
-  while (rangeList.extract(rangesData, &offset))
-    rangeList.dump(OS);
+  if (DumpType == DIDT_All || DumpType == DIDT_InfoDwo)
+    if (getNumDWOCompileUnits()) {
+      OS << "\n.debug_info.dwo contents:\n";
+      for (unsigned i = 0, e = getNumDWOCompileUnits(); i != e; ++i)
+        getDWOCompileUnitAtIndex(i)->dump(OS);
+    }
+
+  if (DumpType == DIDT_All || DumpType == DIDT_StrDwo)
+    if (!getStringDWOSection().empty()) {
+      OS << "\n.debug_str.dwo contents:\n";
+      DataExtractor strDWOData(getStringDWOSection(), isLittleEndian(), 0);
+      offset = 0;
+      uint32_t strDWOOffset = 0;
+      while (const char *s = strDWOData.getCStr(&offset)) {
+        OS << format("0x%8.8x: \"%s\"\n", strDWOOffset, s);
+        strDWOOffset = offset;
+      }
+    }
+
+  if (DumpType == DIDT_All || DumpType == DIDT_StrOffsetsDwo)
+    if (!getStringOffsetDWOSection().empty()) {
+      OS << "\n.debug_str_offsets.dwo contents:\n";
+      DataExtractor strOffsetExt(getStringOffsetDWOSection(), isLittleEndian(), 0);
+      offset = 0;
+      uint64_t size = getStringOffsetDWOSection().size();
+      while (offset < size) {
+        OS << format("0x%8.8x: ", offset);
+        OS << format("%8.8x\n", strOffsetExt.getU32(&offset));
+      }
+    }
 }
 
 const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
@@ -81,6 +160,16 @@ const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
   return Abbrev.get();
 }
 
+const DWARFDebugAbbrev *DWARFContext::getDebugAbbrevDWO() {
+  if (AbbrevDWO)
+    return AbbrevDWO.get();
+
+  DataExtractor abbrData(getAbbrevDWOSection(), isLittleEndian(), 0);
+  AbbrevDWO.reset(new DWARFDebugAbbrev());
+  AbbrevDWO->parse(abbrData);
+  return AbbrevDWO.get();
+}
+
 const DWARFDebugAranges *DWARFContext::getDebugAranges() {
   if (Aranges)
     return Aranges.get();
@@ -89,15 +178,37 @@ const DWARFDebugAranges *DWARFContext::getDebugAranges() {
 
   Aranges.reset(new DWARFDebugAranges());
   Aranges->extract(arangesData);
-  if (Aranges->isEmpty()) // No aranges in file, generate them from the DIEs.
-    Aranges->generate(this);
+  // Generate aranges from DIEs: even if .debug_aranges section is present,
+  // it may describe only a small subset of compilation units, so we need to
+  // manually build aranges for the rest of them.
+  Aranges->generate(this);
   return Aranges.get();
 }
 
-const DWARFDebugLine::LineTable *
+const DWARFDebugFrame *DWARFContext::getDebugFrame() {
+  if (DebugFrame)
+    return DebugFrame.get();
+
+  // There's a "bug" in the DWARFv3 standard with respect to the target address
+  // size within debug frame sections. While DWARF is supposed to be independent
+  // of its container, FDEs have fields with size being "target address size",
+  // which isn't specified in DWARF in general. It's only specified for CUs, but
+  // .eh_frame can appear without a .debug_info section. Follow the example of
+  // other tools (libdwarf) and extract this from the container (ObjectFile
+  // provides this information). This problem is fixed in DWARFv4
+  // See this dwarf-discuss discussion for more details:
+  // http://lists.dwarfstd.org/htdig.cgi/dwarf-discuss-dwarfstd.org/2011-December/001173.html
+  DataExtractor debugFrameData(getDebugFrameSection(), isLittleEndian(),
+                               getAddressSize());
+  DebugFrame.reset(new DWARFDebugFrame());
+  DebugFrame->parse(debugFrameData);
+  return DebugFrame.get();
+}
+
+const DWARFLineTable *
 DWARFContext::getLineTableForCompileUnit(DWARFCompileUnit *cu) {
   if (!Line)
-    Line.reset(new DWARFDebugLine());
+    Line.reset(new DWARFDebugLine(&lineRelocMap()));
 
   unsigned stmtOffset =
     cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list,
@@ -106,7 +217,7 @@ DWARFContext::getLineTableForCompileUnit(DWARFCompileUnit *cu) {
     return 0; // No line table for this compile unit.
 
   // See if the line table is cached.
-  if (const DWARFDebugLine::LineTable *lt = Line->getLineTable(stmtOffset))
+  if (const DWARFLineTable *lt = Line->getLineTable(stmtOffset))
     return lt;
 
   // We have to parse it first.
@@ -117,11 +228,16 @@ DWARFContext::getLineTableForCompileUnit(DWARFCompileUnit *cu) {
 
 void DWARFContext::parseCompileUnits() {
   uint32_t offset = 0;
-  const DataExtractor &debug_info_data = DataExtractor(getInfoSection(),
-                                                       isLittleEndian(), 0);
-  while (debug_info_data.isValidOffset(offset)) {
-    CUs.push_back(DWARFCompileUnit(*this));
-    if (!CUs.back().extract(debug_info_data, &offset)) {
+  const DataExtractor &DIData = DataExtractor(getInfoSection(),
+                                              isLittleEndian(), 0);
+  while (DIData.isValidOffset(offset)) {
+    CUs.push_back(DWARFCompileUnit(getDebugAbbrev(), getInfoSection(),
+                                   getAbbrevSection(), getRangeSection(),
+                                   getStringSection(), StringRef(),
+                                   getAddrSection(),
+                                   &infoRelocMap(),
+                                   isLittleEndian()));
+    if (!CUs.back().extract(DIData, &offset)) {
       CUs.pop_back();
       break;
     }
@@ -130,6 +246,28 @@ void DWARFContext::parseCompileUnits() {
   }
 }
 
+void DWARFContext::parseDWOCompileUnits() {
+  uint32_t offset = 0;
+  const DataExtractor &DIData = DataExtractor(getInfoDWOSection(),
+                                              isLittleEndian(), 0);
+  while (DIData.isValidOffset(offset)) {
+    DWOCUs.push_back(DWARFCompileUnit(getDebugAbbrevDWO(), getInfoDWOSection(),
+                                      getAbbrevDWOSection(),
+                                      getRangeDWOSection(),
+                                      getStringDWOSection(),
+                                      getStringOffsetDWOSection(),
+                                      getAddrSection(),
+                                      &infoDWORelocMap(),
+                                      isLittleEndian()));
+    if (!DWOCUs.back().extract(DIData, &offset)) {
+      DWOCUs.pop_back();
+      break;
+    }
+
+    offset = DWOCUs.back().getNextCompileUnitOffset();
+  }
+}
+
 namespace {
   struct OffsetComparator {
     bool operator()(const DWARFCompileUnit &LHS,
@@ -163,9 +301,11 @@ DWARFCompileUnit *DWARFContext::getCompileUnitForAddress(uint64_t Address) {
   return getCompileUnitForOffset(CUOffset);
 }
 
-static bool getFileNameForCompileUnit(
-    DWARFCompileUnit *CU, const DWARFDebugLine::LineTable *LineTable,
-    uint64_t FileIndex, bool NeedsAbsoluteFilePath, std::string &FileName) {
+static bool getFileNameForCompileUnit(DWARFCompileUnit *CU,
+                                      const DWARFLineTable *LineTable,
+                                      uint64_t FileIndex,
+                                      bool NeedsAbsoluteFilePath,
+                                      std::string &FileName) {
   if (CU == 0 ||
       LineTable == 0 ||
       !LineTable->getFileNameByIndex(FileIndex, NeedsAbsoluteFilePath,
@@ -183,15 +323,13 @@ static bool getFileNameForCompileUnit(
   return true;
 }
 
-bool
-DWARFContext::getFileLineInfoForCompileUnit(DWARFCompileUnit *CU,
-                                            uint64_t Address,
-                                            bool NeedsAbsoluteFilePath,
-                                            std::string &FileName,
-                                            uint32_t &Line, uint32_t &Column) {
-  // Get the line table for this compile unit.
-  const DWARFDebugLine::LineTable *LineTable = getLineTableForCompileUnit(CU);
-  if (!LineTable)
+static bool getFileLineInfoForCompileUnit(DWARFCompileUnit *CU,
+                                          const DWARFLineTable *LineTable,
+                                          uint64_t Address,
+                                          bool NeedsAbsoluteFilePath,
+                                          std::string &FileName,
+                                          uint32_t &Line, uint32_t &Column) {
+  if (CU == 0 || LineTable == 0)
     return false;
   // Get the index of row we're looking for in the line table.
   uint32_t RowIndex = LineTable->lookupAddress(Address);
@@ -217,21 +355,278 @@ DILineInfo DWARFContext::getLineInfoForAddress(uint64_t Address,
   uint32_t Line = 0;
   uint32_t Column = 0;
   if (Specifier.needs(DILineInfoSpecifier::FunctionName)) {
-    const DWARFDebugInfoEntryMinimal *FunctionDIE =
-        CU->getFunctionDIEForAddress(Address);
-    if (FunctionDIE) {
-      if (const char *Name = FunctionDIE->getSubprogramName(CU))
+    // The address may correspond to instruction in some inlined function,
+    // so we have to build the chain of inlined functions and take the
+    // name of the topmost function in it.
+    const DWARFDebugInfoEntryMinimal::InlinedChain &InlinedChain =
+        CU->getInlinedChainForAddress(Address);
+    if (InlinedChain.size() > 0) {
+      const DWARFDebugInfoEntryMinimal &TopFunctionDIE = InlinedChain[0];
+      if (const char *Name = TopFunctionDIE.getSubroutineName(CU))
         FunctionName = Name;
     }
   }
   if (Specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
+    const DWARFLineTable *LineTable = getLineTableForCompileUnit(CU);
     const bool NeedsAbsoluteFilePath =
         Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath);
-    getFileLineInfoForCompileUnit(CU, Address, NeedsAbsoluteFilePath,
+    getFileLineInfoForCompileUnit(CU, LineTable, Address,
+                                  NeedsAbsoluteFilePath,
                                   FileName, Line, Column);
   }
   return DILineInfo(StringRef(FileName), StringRef(FunctionName),
                     Line, Column);
 }
 
+DILineInfoTable DWARFContext::getLineInfoForAddressRange(uint64_t Address,
+    uint64_t Size,
+    DILineInfoSpecifier Specifier) {
+  DILineInfoTable  Lines;
+  DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
+  if (!CU)
+    return Lines;
+
+  std::string FunctionName = "<invalid>";
+  if (Specifier.needs(DILineInfoSpecifier::FunctionName)) {
+    // The address may correspond to instruction in some inlined function,
+    // so we have to build the chain of inlined functions and take the
+    // name of the topmost function in it.
+    const DWARFDebugInfoEntryMinimal::InlinedChain &InlinedChain =
+        CU->getInlinedChainForAddress(Address);
+    if (InlinedChain.size() > 0) {
+      const DWARFDebugInfoEntryMinimal &TopFunctionDIE = InlinedChain[0];
+      if (const char *Name = TopFunctionDIE.getSubroutineName(CU))
+        FunctionName = Name;
+    }
+  }
+
+  StringRef  FuncNameRef = StringRef(FunctionName);
+
+  // If the Specifier says we don't need FileLineInfo, just
+  // return the top-most function at the starting address.
+  if (!Specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
+    Lines.push_back(std::make_pair(Address, 
+                                   DILineInfo(StringRef("<invalid>"), 
+                                              FuncNameRef, 0, 0)));
+    return Lines;
+  }
+
+  const DWARFLineTable *LineTable = getLineTableForCompileUnit(CU);
+  const bool NeedsAbsoluteFilePath =
+      Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath);
+
+  // Get the index of row we're looking for in the line table.
+  std::vector<uint32_t> RowVector;
+  if (!LineTable->lookupAddressRange(Address, Size, RowVector))
+    return Lines;
+
+  uint32_t NumRows = RowVector.size();
+  for (uint32_t i = 0; i < NumRows; ++i) {
+    uint32_t RowIndex = RowVector[i];
+    // Take file number and line/column from the row.
+    const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
+    std::string FileName = "<invalid>";
+    getFileNameForCompileUnit(CU, LineTable, Row.File,
+                              NeedsAbsoluteFilePath, FileName);
+    Lines.push_back(std::make_pair(Row.Address, 
+                                   DILineInfo(StringRef(FileName),
+                                         FuncNameRef, Row.Line, Row.Column)));
+  }
+
+  return Lines;
+}
+
+DIInliningInfo DWARFContext::getInliningInfoForAddress(uint64_t Address,
+    DILineInfoSpecifier Specifier) {
+  DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
+  if (!CU)
+    return DIInliningInfo();
+
+  const DWARFDebugInfoEntryMinimal::InlinedChain &InlinedChain =
+      CU->getInlinedChainForAddress(Address);
+  if (InlinedChain.size() == 0)
+    return DIInliningInfo();
+
+  DIInliningInfo InliningInfo;
+  uint32_t CallFile = 0, CallLine = 0, CallColumn = 0;
+  const DWARFLineTable *LineTable = 0;
+  for (uint32_t i = 0, n = InlinedChain.size(); i != n; i++) {
+    const DWARFDebugInfoEntryMinimal &FunctionDIE = InlinedChain[i];
+    std::string FileName = "<invalid>";
+    std::string FunctionName = "<invalid>";
+    uint32_t Line = 0;
+    uint32_t Column = 0;
+    // Get function name if necessary.
+    if (Specifier.needs(DILineInfoSpecifier::FunctionName)) {
+      if (const char *Name = FunctionDIE.getSubroutineName(CU))
+        FunctionName = Name;
+    }
+    if (Specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
+      const bool NeedsAbsoluteFilePath =
+          Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath);
+      if (i == 0) {
+        // For the topmost frame, initialize the line table of this
+        // compile unit and fetch file/line info from it.
+        LineTable = getLineTableForCompileUnit(CU);
+        // For the topmost routine, get file/line info from line table.
+        getFileLineInfoForCompileUnit(CU, LineTable, Address,
+                                      NeedsAbsoluteFilePath,
+                                      FileName, Line, Column);
+      } else {
+        // Otherwise, use call file, call line and call column from
+        // previous DIE in inlined chain.
+        getFileNameForCompileUnit(CU, LineTable, CallFile,
+                                  NeedsAbsoluteFilePath, FileName);
+        Line = CallLine;
+        Column = CallColumn;
+      }
+      // Get call file/line/column of a current DIE.
+      if (i + 1 < n) {
+        FunctionDIE.getCallerFrame(CU, CallFile, CallLine, CallColumn);
+      }
+    }
+    DILineInfo Frame(StringRef(FileName), StringRef(FunctionName),
+                     Line, Column);
+    InliningInfo.addFrame(Frame);
+  }
+  return InliningInfo;
+}
+
+static bool consumeCompressedDebugSectionHeader(StringRef &data,
+                                                uint64_t &OriginalSize) {
+  // Consume "ZLIB" prefix.
+  if (!data.startswith("ZLIB"))
+    return false;
+  data = data.substr(4);
+  // Consume uncompressed section size (big-endian 8 bytes).
+  DataExtractor extractor(data, false, 8);
+  uint32_t Offset = 0;
+  OriginalSize = extractor.getU64(&Offset);
+  if (Offset == 0)
+    return false;
+  data = data.substr(Offset);
+  return true;
+}
+
+DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
+  IsLittleEndian(Obj->isLittleEndian()),
+  AddressSize(Obj->getBytesInAddress()) {
+  error_code ec;
+  for (object::section_iterator i = Obj->begin_sections(),
+         e = Obj->end_sections();
+       i != e; i.increment(ec)) {
+    StringRef name;
+    i->getName(name);
+    StringRef data;
+    i->getContents(data);
+
+    name = name.substr(name.find_first_not_of("._")); // Skip . and _ prefixes.
+
+    // Check if debug info section is compressed with zlib.
+    if (name.startswith("zdebug_")) {
+      uint64_t OriginalSize;
+      if (!zlib::isAvailable() ||
+          !consumeCompressedDebugSectionHeader(data, OriginalSize))
+        continue;
+      OwningPtr<MemoryBuffer> UncompressedSection;
+      if (zlib::uncompress(data, UncompressedSection, OriginalSize) !=
+          zlib::StatusOK)
+        continue;
+      // Make data point to uncompressed section contents and save its contents.
+      name = name.substr(1);
+      data = UncompressedSection->getBuffer();
+      UncompressedSections.push_back(UncompressedSection.take());
+    }
+
+    StringRef *Section = StringSwitch<StringRef*>(name)
+        .Case("debug_info", &InfoSection)
+        .Case("debug_abbrev", &AbbrevSection)
+        .Case("debug_line", &LineSection)
+        .Case("debug_aranges", &ARangeSection)
+        .Case("debug_frame", &DebugFrameSection)
+        .Case("debug_str", &StringSection)
+        .Case("debug_ranges", &RangeSection)
+        .Case("debug_pubnames", &PubNamesSection)
+        .Case("debug_info.dwo", &InfoDWOSection)
+        .Case("debug_abbrev.dwo", &AbbrevDWOSection)
+        .Case("debug_str.dwo", &StringDWOSection)
+        .Case("debug_str_offsets.dwo", &StringOffsetDWOSection)
+        .Case("debug_addr", &AddrSection)
+        // Any more debug info sections go here.
+        .Default(0);
+    if (!Section)
+      continue;
+    *Section = data;
+    if (name == "debug_ranges") {
+      // FIXME: Use the other dwo range section when we emit it.
+      RangeDWOSection = data;
+    }
+
+    // TODO: Add support for relocations in other sections as needed.
+    // Record relocations for the debug_info and debug_line sections.
+    RelocAddrMap *Map = StringSwitch<RelocAddrMap*>(name)
+        .Case("debug_info", &InfoRelocMap)
+        .Case("debug_info.dwo", &InfoDWORelocMap)
+        .Case("debug_line", &LineRelocMap)
+        .Default(0);
+    if (!Map)
+      continue;
+
+    if (i->begin_relocations() != i->end_relocations()) {
+      uint64_t SectionSize;
+      i->getSize(SectionSize);
+      for (object::relocation_iterator reloc_i = i->begin_relocations(),
+             reloc_e = i->end_relocations();
+           reloc_i != reloc_e; reloc_i.increment(ec)) {
+        uint64_t Address;
+        reloc_i->getOffset(Address);
+        uint64_t Type;
+        reloc_i->getType(Type);
+        uint64_t SymAddr = 0;
+        // ELF relocations may need the symbol address
+        if (Obj->isELF()) {
+          object::SymbolRef Sym;
+          reloc_i->getSymbol(Sym);
+          Sym.getAddress(SymAddr);
+        }
+
+        object::RelocVisitor V(Obj->getFileFormatName());
+        // The section address is always 0 for debug sections.
+        object::RelocToApply R(V.visit(Type, *reloc_i, 0, SymAddr));
+        if (V.error()) {
+          SmallString<32> Name;
+          error_code ec(reloc_i->getTypeName(Name));
+          if (ec) {
+            errs() << "Aaaaaa! Nameless relocation! Aaaaaa!\n";
+          }
+          errs() << "error: failed to compute relocation: "
+                 << Name << "\n";
+          continue;
+        }
+
+        if (Address + R.Width > SectionSize) {
+          errs() << "error: " << R.Width << "-byte relocation starting "
+                 << Address << " bytes into section " << name << " which is "
+                 << SectionSize << " bytes long.\n";
+          continue;
+        }
+        if (R.Width > 8) {
+          errs() << "error: can't handle a relocation of more than 8 bytes at "
+                    "a time.\n";
+          continue;
+        }
+        DEBUG(dbgs() << "Writing " << format("%p", R.Value)
+                     << " at " << format("%p", Address)
+                     << " with width " << format("%d", R.Width)
+                     << "\n");
+        Map->insert(std::make_pair(Address, std::make_pair(R.Width, R.Value)));
+      }
+    }
+  }
+}
+
+DWARFContextInMemory::~DWARFContextInMemory() {
+  DeleteContainerPointers(UncompressedSections);
+}
+
 void DWARFContextInMemory::anchor() { }