Revert "[DWARF] reposting r342048, which was reverted in r342056 due to buildbot errors. Adjusted 2 test cases for ARM and darwin and fixed a bug with the original change in dsymutil."

This reverts commit r342218. Due to a number of failures under TSAN. An isolated
test case is being worked on.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342399 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/DebugInfo/DWARF/DWARFContext.h

@@ -231,9 +231,7 @@ public:
   /// Get a DIE given an exact offset.
   DWARFDie getDIEForOffset(uint32_t Offset);
 
-  unsigned getMaxVersion(uint16_t DefaultVersion = 0) const {
-    return MaxVersion ? MaxVersion : DefaultVersion;
-  }
+  unsigned getMaxVersion() const { return MaxVersion; }
 
   void setMaxVersionIfGreater(unsigned Version) {
     if (Version > MaxVersion)

include/llvm/DebugInfo/DWARF/DWARFDebugRangeList.h

@@ -0,0 +1,86 @@
+//===- DWARFDebugRangeList.h ------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_DWARF_DWARFDEBUGRANGELIST_H
+#define LLVM_DEBUGINFO_DWARF_DWARFDEBUGRANGELIST_H
+
+#include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
+#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
+#include <cassert>
+#include <cstdint>
+#include <vector>
+
+namespace llvm {
+
+struct BaseAddress;
+class raw_ostream;
+
+class DWARFDebugRangeList {
+public:
+  struct RangeListEntry {
+    /// A beginning address offset. This address offset has the size of an
+    /// address and is relative to the applicable base address of the
+    /// compilation unit referencing this range list. It marks the beginning
+    /// of an address range.
+    uint64_t StartAddress;
+    /// An ending address offset. This address offset again has the size of
+    /// an address and is relative to the applicable base address of the
+    /// compilation unit referencing this range list. It marks the first
+    /// address past the end of the address range. The ending address must
+    /// be greater than or equal to the beginning address.
+    uint64_t EndAddress;
+    /// A section index this range belongs to.
+    uint64_t SectionIndex;
+
+    /// The end of any given range list is marked by an end of list entry,
+    /// which consists of a 0 for the beginning address offset
+    /// and a 0 for the ending address offset.
+    bool isEndOfListEntry() const {
+      return (StartAddress == 0) && (EndAddress == 0);
+    }
+
+    /// A base address selection entry consists of:
+    /// 1. The value of the largest representable address offset
+    /// (for example, 0xffffffff when the size of an address is 32 bits).
+    /// 2. An address, which defines the appropriate base address for
+    /// use in interpreting the beginning and ending address offsets of
+    /// subsequent entries of the location list.
+    bool isBaseAddressSelectionEntry(uint8_t AddressSize) const {
+      assert(AddressSize == 4 || AddressSize == 8);
+      if (AddressSize == 4)
+        return StartAddress == -1U;
+      else
+        return StartAddress == -1ULL;
+    }
+  };
+
+private:
+  /// Offset in .debug_ranges section.
+  uint32_t Offset;
+  uint8_t AddressSize;
+  std::vector<RangeListEntry> Entries;
+
+public:
+  DWARFDebugRangeList() { clear(); }
+
+  void clear();
+  void dump(raw_ostream &OS) const;
+  Error extract(const DWARFDataExtractor &data, uint32_t *offset_ptr);
+  const std::vector<RangeListEntry> &getEntries() { return Entries; }
+
+  /// getAbsoluteRanges - Returns absolute address ranges defined by this range
+  /// list. Has to be passed base address of the compile unit referencing this
+  /// range list.
+  DWARFAddressRangesVector
+  getAbsoluteRanges(llvm::Optional<BaseAddress> BaseAddr) const;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_DEBUGINFO_DWARF_DWARFDEBUGRANGELIST_H

include/llvm/DebugInfo/DWARF/DWARFDebugRnglists.h

@@ -12,8 +12,8 @@
 
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DIContext.h"
-#include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/DebugInfo/DWARF/DWARFListTable.h"
 #include <cstdint>
 #include <map>
@@ -21,8 +21,6 @@
 
 namespace llvm {
 
-struct BaseAddress;
-class DWARFContext;
 class Error;
 class raw_ostream;
 
@@ -35,29 +33,10 @@ struct RangeListEntry : public DWARFListEntryBase {
   uint64_t Value0;
   uint64_t Value1;
 
-  Error extract(DWARFDataExtractor Data, uint32_t End, uint16_t Version,
-                StringRef SectionName, uint32_t *OffsetPtr, bool isDWO = false);
-  bool isEndOfList() const { return EntryKind == dwarf::DW_RLE_end_of_list; }
-  bool isBaseAddressSelectionEntry() const {
-    return EntryKind == dwarf::DW_RLE_base_address;
-  }
-  uint64_t getStartAddress() const {
-    assert((EntryKind == dwarf::DW_RLE_start_end ||
-            EntryKind == dwarf::DW_RLE_offset_pair ||
-            EntryKind == dwarf::DW_RLE_startx_length) &&
-           "Unexpected range list entry kind");
-    return Value0;
-  }
-  uint64_t getEndAddress() const {
-    assert((EntryKind == dwarf::DW_RLE_start_end ||
-            EntryKind == dwarf::DW_RLE_offset_pair) &&
-           "Unexpected range list entry kind");
-    return Value1;
-  }
-  void dump(raw_ostream &OS, DWARFContext *C, uint8_t AddrSize,
-            uint64_t &CurrentBase, unsigned Indent, uint16_t Version,
-            uint8_t MaxEncodingStringLength = 0,
-            DIDumpOptions DumpOpts = {}) const;
+  Error extract(DWARFDataExtractor Data, uint32_t End, uint32_t *OffsetPtr);
+  void dump(raw_ostream &OS, uint8_t AddrSize, uint8_t MaxEncodingStringLength,
+            uint64_t &CurrentBase, DIDumpOptions DumpOpts) const;
+  bool isSentinel() const { return EntryKind == dwarf::DW_RLE_end_of_list; }
 };
 
 /// A class representing a single rangelist.
@@ -70,12 +49,10 @@ public:
 
 class DWARFDebugRnglistTable : public DWARFListTableBase<DWARFDebugRnglist> {
 public:
-  DWARFDebugRnglistTable(DWARFContext *C, StringRef SectionName,
-                         bool isDWO = false)
-      : DWARFListTableBase(C, SectionName, isDWO,
+  DWARFDebugRnglistTable()
+      : DWARFListTableBase(/* SectionName    = */ ".debug_rnglists",
                            /* HeaderString   = */ "ranges:",
-                           /* ListTypeString = */ "range",
-                           dwarf::RangeListEncodingString) {}
+                           /* ListTypeString = */ "range") {}
 };
 
 } // end namespace llvm

include/llvm/DebugInfo/DWARF/DWARFListTable.h

@@ -23,8 +23,6 @@
 
 namespace llvm {
 
-class DWARFContext;
-
 /// A base class for DWARF list entries, such as range or location list
 /// entries.
 struct DWARFListEntryBase {
@@ -39,7 +37,6 @@ struct DWARFListEntryBase {
 /// A base class for lists of entries that are extracted from a particular
 /// section, such as range lists or location lists.
 template <typename ListEntryType> class DWARFListType {
-public:
   using EntryType = ListEntryType;
   using ListEntries = std::vector<EntryType>;
 
@@ -48,26 +45,11 @@ protected:
 
 public:
   const ListEntries &getEntries() const { return Entries; }
-  bool empty() const {
-    return Entries.empty() || Entries.begin()->isEndOfList();
-  }
+  bool empty() const { return Entries.empty(); }
   void clear() { Entries.clear(); }
-  uint32_t getOffset() const {
-    if (Entries.empty())
-      return 0;
-    return Entries.begin()->Offset;
-  }
-
-  /// Extract a list. The caller must pass the correct DWARF version.
-  /// The end-of-list entry is retained as the last element of the vector of
-  /// entries.
   Error extract(DWARFDataExtractor Data, uint32_t HeaderOffset, uint32_t End,
-                uint16_t Version, uint32_t *OffsetPtr, StringRef SectionName,
-                StringRef ListStringName, bool isDWO = false);
-  void dump(raw_ostream &OS, DWARFContext *C, uint8_t AddressSize,
-            uint64_t BaseAddress, unsigned Indent, uint16_t Version,
-            size_t MaxEncodingStringLength = 0,
-            DIDumpOptions DumpOpts = {}) const;
+                uint32_t *OffsetPtr, StringRef SectionName,
+                StringRef ListStringName);
 };
 
 /// A class representing the header of a list table such as the range list
@@ -85,9 +67,9 @@ class DWARFListTableHeader {
     uint8_t AddrSize;
     /// The size in bytes of a segment selector on the target architecture.
     /// If the target system uses a flat address space, this value is 0.
-    uint8_t SegSize = 0;
+    uint8_t SegSize;
     /// The number of offsets that follow the header before the range lists.
-    uint32_t OffsetEntryCount = 0;
+    uint32_t OffsetEntryCount;
   };
 
   Header HeaderData;
@@ -96,10 +78,10 @@ class DWARFListTableHeader {
   /// FIXME: Generate the table and use the appropriate forms.
   std::vector<uint32_t> Offsets;
   /// The table's format, either DWARF32 or DWARF64.
-  dwarf::DwarfFormat Format = dwarf::DwarfFormat::DWARF32;
+  dwarf::DwarfFormat Format;
   /// The offset at which the header (and hence the table) is located within
   /// its section.
-  uint32_t HeaderOffset = 0;
+  uint32_t HeaderOffset;
   /// The name of the section the list is located in.
   StringRef SectionName;
   /// A characterization of the list for dumping purposes, e.g. "range" or
@@ -115,19 +97,8 @@ public:
     Offsets.clear();
   }
   uint32_t getHeaderOffset() const { return HeaderOffset; }
-
   uint8_t getAddrSize() const { return HeaderData.AddrSize; }
-  void setAddrSize(uint8_t AddrSize) { HeaderData.AddrSize = AddrSize; }
-
   uint32_t getLength() const { return HeaderData.Length; }
-  void setLength(uint32_t Length) { HeaderData.Length = Length; }
-
-  uint16_t getVersion() const { return HeaderData.Version; }
-  void setVersion(uint16_t Version) { HeaderData.Version = Version; }
-
-  uint8_t getSegSize() const { return HeaderData.SegSize; }
-  uint32_t getOffsetEntryCount() const { return HeaderData.OffsetEntryCount; }
-
   StringRef getSectionName() const { return SectionName; }
   StringRef getListTypeString() const { return ListTypeString; }
   dwarf::DwarfFormat getFormat() const { return Format; }
@@ -144,10 +115,8 @@ public:
 
   /// Returns the length of the table, including the length field, or 0 if the
   /// length has not been determined (e.g. because the table has not yet been
-  /// parsed, or there was a problem in parsing). In fake tables, such as for
-  /// DWARF v4 and earlier, there is no header, so the length simply reflects
-  /// the size of the section.
-  uint32_t getTableLength() const;
+  /// parsed, or there was a problem in parsing).
+  uint32_t length() const;
 };
 
 /// A class representing a table of lists as specified in the DWARF v5
@@ -160,22 +129,14 @@ template <typename DWARFListType> class DWARFListTableBase {
   /// A mapping between file offsets and lists. It is used to find a particular
   /// list based on an offset (obtained from DW_AT_ranges, for example).
   std::map<uint32_t, DWARFListType> ListMap;
-  DWARFContext *C;
-  /// True if this list is located in a split-DWARF (dwo or dwp) file.
-  bool isDWO;
   /// This string is displayed as a heading before the list is dumped
   /// (e.g. "ranges:").
   StringRef HeaderString;
-  /// A function returning the encoding string for a given list entry encoding,
-  /// e.g. "DW_RLE_start_end".
-  std::function<StringRef(unsigned)> EncodingString;
 
 protected:
-  DWARFListTableBase(DWARFContext *C, StringRef SectionName, bool isDWO,
-                     StringRef HeaderString, StringRef ListTypeString,
-                     std::function<StringRef(unsigned)> EncodingString)
-      : Header(SectionName, ListTypeString), C(C), isDWO(isDWO),
-        HeaderString(HeaderString), EncodingString(EncodingString) {}
+  DWARFListTableBase(StringRef SectionName, StringRef HeaderString,
+                     StringRef ListTypeString)
+      : Header(SectionName, ListTypeString), HeaderString(HeaderString) {}
 
 public:
   void clear() {
@@ -186,28 +147,14 @@ public:
   Error extractHeaderAndOffsets(DWARFDataExtractor Data, uint32_t *OffsetPtr) {
     return Header.extract(Data, OffsetPtr);
   }
-
-  /// Initialize the table header to explicit values. This is used for DWARF v4
-  /// and earlier since there is no header that can be extracted from a section.
-  void setHeaderData(uint32_t Length, uint16_t Version, uint8_t AddrSize) {
-    assert(Header.getSegSize() == 0 &&
-           "Unexpected segsize in list table header.");
-    assert(Header.getOffsetEntryCount() == 0 &&
-           "Unexpected offset entry count in list table header.");
-    Header.setLength(Length);
-    Header.setVersion(Version);
-    Header.setAddrSize(AddrSize);
-  }
-
   /// Extract an entire table, including all list entries.
-  Error extract(DWARFDataExtractor Data, uint16_t Version, uint32_t *OffsetPtr);
+  Error extract(DWARFDataExtractor Data, uint32_t *OffsetPtr);
   /// Look up a list based on a given offset. Extract it and enter it into the
   /// list map if necessary.
   Expected<DWARFListType> findList(DWARFDataExtractor Data, uint32_t Offset);
 
   uint32_t getHeaderOffset() const { return Header.getHeaderOffset(); }
   uint8_t getAddrSize() const { return Header.getAddrSize(); }
-  StringRef getListTypeString() const { return Header.getListTypeString(); }
 
   void dump(raw_ostream &OS, DIDumpOptions DumpOpts = {}) const;
 
@@ -228,35 +175,25 @@ public:
     llvm_unreachable("Invalid DWARF format (expected DWARF32 or DWARF64");
   }
 
-  uint16_t getVersion() const { return Header.getVersion(); }
-  uint32_t getLength() const { return Header.getTableLength(); }
+  uint32_t length() { return Header.length(); }
 };
 
 template <typename DWARFListType>
 Error DWARFListTableBase<DWARFListType>::extract(DWARFDataExtractor Data,
-                                                 uint16_t Version,
                                                  uint32_t *OffsetPtr) {
-  assert(Version > 0 && "DWARF version required and not given.");
   clear();
-  // For DWARF v4 and earlier, we cannot extract a table header, so we
-  // initialize it explicitly.
-  if (Version < 5)
-    setHeaderData(Data.size(), Version, Data.getAddressSize());
-  else if (Error E = extractHeaderAndOffsets(Data, OffsetPtr))
+  if (Error E = extractHeaderAndOffsets(Data, OffsetPtr))
     return E;
 
   Data.setAddressSize(Header.getAddrSize());
-  uint32_t End = getHeaderOffset() + getLength();
-  // Extract all lists.
+  uint32_t End = getHeaderOffset() + Header.length();
   while (*OffsetPtr < End) {
     DWARFListType CurrentList;
     uint32_t Off = *OffsetPtr;
-    if (Error E = CurrentList.extract(
-            Data, getHeaderOffset(), End, Header.getVersion(), OffsetPtr,
-            Header.getSectionName(), Header.getListTypeString(), isDWO)) {
-      *OffsetPtr = End;
+    if (Error E = CurrentList.extract(Data, getHeaderOffset(), End, OffsetPtr,
+                                      Header.getSectionName(),
+                                      Header.getListTypeString()))
       return E;
-    }
     ListMap[Off] = CurrentList;
   }
 
@@ -267,10 +204,11 @@ Error DWARFListTableBase<DWARFListType>::extract(DWARFDataExtractor Data,
 }
 
 template <typename ListEntryType>
-Error DWARFListType<ListEntryType>::extract(
-    DWARFDataExtractor Data, uint32_t HeaderOffset, uint32_t End,
-    uint16_t Version, uint32_t *OffsetPtr, StringRef SectionName,
-    StringRef ListTypeString, bool isDWO) {
+Error DWARFListType<ListEntryType>::extract(DWARFDataExtractor Data,
+                                            uint32_t HeaderOffset, uint32_t End,
+                                            uint32_t *OffsetPtr,
+                                            StringRef SectionName,
+                                            StringRef ListTypeString) {
   if (*OffsetPtr < HeaderOffset || *OffsetPtr >= End)
     return createStringError(errc::invalid_argument,
                        "invalid %s list offset 0x%" PRIx32,
@@ -278,11 +216,10 @@ Error DWARFListType<ListEntryType>::extract(
   Entries.clear();
   while (*OffsetPtr < End) {
     ListEntryType Entry;
-    if (Error E =
-            Entry.extract(Data, End, Version, SectionName, OffsetPtr, isDWO))
+    if (Error E = Entry.extract(Data, End, OffsetPtr))
       return E;
     Entries.push_back(Entry);
-    if (Entry.isEndOfList())
+    if (Entry.isSentinel())
       return Error::success();
   }
   return createStringError(errc::illegal_byte_sequence,
@@ -291,41 +228,28 @@ Error DWARFListType<ListEntryType>::extract(
                      SectionName.data(), HeaderOffset);
 }
 
-template <typename ListEntryType>
-void DWARFListType<ListEntryType>::dump(raw_ostream &OS, DWARFContext *C,
-                                        uint8_t AddressSize,
-                                        uint64_t BaseAddress, unsigned Indent,
-                                        uint16_t Version,
-                                        size_t MaxEncodingStringLength,
-                                        DIDumpOptions DumpOpts) const {
-  uint64_t CurrentBase = BaseAddress;
-  for (const auto &Entry : Entries)
-    Entry.dump(OS, C, AddressSize, CurrentBase, Indent, Version,
-               MaxEncodingStringLength, DumpOpts);
-}
-
 template <typename DWARFListType>
 void DWARFListTableBase<DWARFListType>::dump(raw_ostream &OS,
                                              DIDumpOptions DumpOpts) const {
+  Header.dump(OS, DumpOpts);
+  OS << HeaderString << "\n";
+
+  // Determine the length of the longest encoding string we have in the table,
+  // so we can align the output properly. We only need this in verbose mode.
   size_t MaxEncodingStringLength = 0;
-  // Don't dump the fake table header we create for DWARF v4 and earlier.
-  if (Header.getVersion() > 4) {
-    Header.dump(OS, DumpOpts);
-    OS << HeaderString << '\n';
-    // Determine the length of the longest encoding string we have in the table,
-    // so we can align the output properly. We only need this in verbose mode.
-    if (DumpOpts.Verbose)
-      for (const auto &List : ListMap)
-        for (const auto &Entry : List.second.getEntries())
-          MaxEncodingStringLength = std::max(
-              MaxEncodingStringLength, EncodingString(Entry.EntryKind).size());
+  if (DumpOpts.Verbose) {
+    for (const auto &List : ListMap)
+      for (const auto &Entry : List.second.getEntries())
+        MaxEncodingStringLength =
+            std::max(MaxEncodingStringLength,
+                     dwarf::RangeListEncodingString(Entry.EntryKind).size());
   }
 
   uint64_t CurrentBase = 0;
-  for (const auto &List : ListMap) {
-    List.second.dump(OS, C, getAddrSize(), CurrentBase, 0, Header.getVersion(),
-                     MaxEncodingStringLength, DumpOpts);
-  }
+  for (const auto &List : ListMap)
+    for (const auto &Entry : List.second.getEntries())
+      Entry.dump(OS, getAddrSize(), MaxEncodingStringLength, CurrentBase,
+                 DumpOpts);
 }
 
 template <typename DWARFListType>
@@ -338,11 +262,11 @@ DWARFListTableBase<DWARFListType>::findList(DWARFDataExtractor Data,
 
   // Extract the list from the section and enter it into the list map.
   DWARFListType List;
-  uint32_t End = getHeaderOffset() + getLength();
+  uint32_t End = getHeaderOffset() + Header.length();
   uint32_t StartingOffset = Offset;
-  if (Error E = List.extract(Data, getHeaderOffset(), End, Header.getVersion(),
-                             &Offset, Header.getSectionName(),
-                             Header.getListTypeString(), isDWO))
+  if (Error E =
+          List.extract(Data, getHeaderOffset(), End, &Offset,
+                       Header.getSectionName(), Header.getListTypeString()))
     return std::move(E);
   ListMap[StartingOffset] = List;
   return List;

include/llvm/DebugInfo/DWARF/DWARFUnit.h

@@ -17,6 +17,7 @@
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugRnglists.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
@@ -305,6 +306,12 @@ public:
     return DataExtractor(StringSection, false, 0);
   }
 
+  /// Extract the range list referenced by this compile unit from the
+  /// .debug_ranges section. If the extraction is unsuccessful, an error
+  /// is returned. Successful extraction requires that the compile unit
+  /// has already been extracted.
+  Error extractRangeList(uint32_t RangeListOffset,
+                         DWARFDebugRangeList &RangeList) const;
   void clear();
 
   const Optional<StrOffsetsContributionDescriptor> &

lib/DebugInfo/DWARF/CMakeLists.txt

@@ -15,6 +15,7 @@ add_llvm_library(LLVMDebugInfoDWARF
   DWARFDebugLoc.cpp
   DWARFDebugMacro.cpp
   DWARFDebugPubTable.cpp
+  DWARFDebugRangeList.cpp
   DWARFDebugRnglists.cpp
   DWARFDie.cpp
   DWARFExpression.cpp

lib/DebugInfo/DWARF/DWARFContext.cpp

@@ -25,6 +25,7 @@
 #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugPubTable.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugRnglists.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
@@ -266,29 +267,24 @@ static void dumpAddrSection(raw_ostream &OS, DWARFDataExtractor &AddrData,
   }
 }
 
-// Dump a section that contains a sequence of tables of lists, such as range
-// or location list tables. In DWARF v5 we expect to find properly formatted
-// tables with headers. In DWARF v4 and earlier we simply expect a sequence of
-// lists, which we treat, mutatis mutandis, like DWARF v5 tables.
-template <typename ListTable>
-static void dumpListSection(raw_ostream &OS, DWARFContext *C,
-                            StringRef SectionName, uint16_t MaxVersion,
-                            DWARFDataExtractor &ListData,
-                            DIDumpOptions DumpOpts, bool isDWO = false) {
+// Dump the .debug_rnglists or .debug_rnglists.dwo section (DWARF v5).
+static void dumpRnglistsSection(raw_ostream &OS,
+                                DWARFDataExtractor &rnglistData,
+                                DIDumpOptions DumpOpts) {
   uint32_t Offset = 0;
-  while (ListData.isValidOffset(Offset)) {
-    ListTable Table(C, SectionName, isDWO);
-    if (Error Err = Table.extract(ListData, MaxVersion, &Offset)) {
+  while (rnglistData.isValidOffset(Offset)) {
+    llvm::DWARFDebugRnglistTable Rnglists;
+    uint32_t TableOffset = Offset;
+    if (Error Err = Rnglists.extract(rnglistData, &Offset)) {
       WithColor::error() << toString(std::move(Err)) << '\n';
-      // If table extraction set Offset to 0, it indicates that we cannot
-      // continue to read the section.
-      if (Offset == 0)
+      uint64_t Length = Rnglists.length();
+      // Keep going after an error, if we can, assuming that the length field
+      // could be read. If it couldn't, stop reading the section.
+      if (Length == 0)
         break;
-      // In DWARF v4 and earlier, dump as much of the lists as we can.
-      if (MaxVersion < 5)
-        Table.dump(OS, DumpOpts);
+      Offset = TableOffset + Length;
     } else {
-      Table.dump(OS, DumpOpts);
+      Rnglists.dump(OS, DumpOpts);
     }
   }
 }
@@ -488,25 +484,29 @@ void DWARFContext::dump(
     uint8_t savedAddressByteSize = getCUAddrSize();
     DWARFDataExtractor rangesData(*DObj, DObj->getRangeSection(),
                                   isLittleEndian(), savedAddressByteSize);
-    dumpListSection<DWARFDebugRnglistTable>(
-        OS, this, ".debug_ranges", /* MaxVersion = */ 4, rangesData, DumpOpts);
+    uint32_t offset = 0;
+    DWARFDebugRangeList rangeList;
+    while (rangesData.isValidOffset(offset)) {
+      if (Error E = rangeList.extract(rangesData, &offset)) {
+        WithColor::error() << toString(std::move(E)) << '\n';
+        break;
+      }
+      rangeList.dump(OS);
+    }
   }
 
   if (shouldDump(Explicit, ".debug_rnglists", DIDT_ID_DebugRnglists,
                  DObj->getRnglistsSection().Data)) {
     DWARFDataExtractor RnglistData(*DObj, DObj->getRnglistsSection(),
-                                   isLittleEndian(), getCUAddrSize());
-    dumpListSection<DWARFDebugRnglistTable>(
-        OS, this, ".debug_rnglists", getMaxVersion(5), RnglistData, DumpOpts);
+                                   isLittleEndian(), 0);
+    dumpRnglistsSection(OS, RnglistData, DumpOpts);
   }
 
   if (shouldDump(ExplicitDWO, ".debug_rnglists.dwo", DIDT_ID_DebugRnglists,
                  DObj->getRnglistsDWOSection().Data)) {
     DWARFDataExtractor RnglistData(*DObj, DObj->getRnglistsDWOSection(),
-                                   isLittleEndian(), getCUAddrSize());
-    dumpListSection<DWARFDebugRnglistTable>(OS, this, ".debug_rnglists.dwo",
-                                            getMaxVersion(5), RnglistData,
-                                            DumpOpts);
+                                   isLittleEndian(), 0);
+    dumpRnglistsSection(OS, RnglistData, DumpOpts);
   }
 
   if (shouldDump(Explicit, ".debug_pubnames", DIDT_ID_DebugPubnames,

lib/DebugInfo/DWARF/DWARFDebugRangeList.cpp

@@ -0,0 +1,96 @@
+//===- DWARFDebugRangesList.cpp -------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cinttypes>
+#include <cstdint>
+
+using namespace llvm;
+
+void DWARFDebugRangeList::clear() {
+  Offset = -1U;
+  AddressSize = 0;
+  Entries.clear();
+}
+
+Error DWARFDebugRangeList::extract(const DWARFDataExtractor &data,
+                                   uint32_t *offset_ptr) {
+  clear();
+  if (!data.isValidOffset(*offset_ptr))
+    return createStringError(errc::invalid_argument,
+                       "invalid range list offset 0x%" PRIx32, *offset_ptr);
+
+  AddressSize = data.getAddressSize();
+  if (AddressSize != 4 && AddressSize != 8)
+    return createStringError(errc::invalid_argument,
+                       "invalid address size: %" PRIu8, AddressSize);
+  Offset = *offset_ptr;
+  while (true) {
+    RangeListEntry Entry;
+    Entry.SectionIndex = -1ULL;
+
+    uint32_t prev_offset = *offset_ptr;
+    Entry.StartAddress = data.getRelocatedAddress(offset_ptr);
+    Entry.EndAddress =
+        data.getRelocatedAddress(offset_ptr, &Entry.SectionIndex);
+
+    // Check that both values were extracted correctly.
+    if (*offset_ptr != prev_offset + 2 * AddressSize) {
+      clear();
+      return createStringError(errc::invalid_argument,
+                         "invalid range list entry at offset 0x%" PRIx32,
+                         prev_offset);
+    }
+    if (Entry.isEndOfListEntry())
+      break;
+    Entries.push_back(Entry);
+  }
+  return Error::success();
+}
+
+void DWARFDebugRangeList::dump(raw_ostream &OS) const {
+  for (const RangeListEntry &RLE : Entries) {
+    const char *format_str = (AddressSize == 4
+                              ? "%08x %08"  PRIx64 " %08"  PRIx64 "\n"
+                              : "%08x %016" PRIx64 " %016" PRIx64 "\n");
+    OS << format(format_str, Offset, RLE.StartAddress, RLE.EndAddress);
+  }
+  OS << format("%08x <End of list>\n", Offset);
+}
+
+DWARFAddressRangesVector DWARFDebugRangeList::getAbsoluteRanges(
+    llvm::Optional<BaseAddress> BaseAddr) const {
+  DWARFAddressRangesVector Res;
+  for (const RangeListEntry &RLE : Entries) {
+    if (RLE.isBaseAddressSelectionEntry(AddressSize)) {
+      BaseAddr = {RLE.EndAddress, RLE.SectionIndex};
+      continue;
+    }
+
+    DWARFAddressRange E;
+    E.LowPC = RLE.StartAddress;
+    E.HighPC = RLE.EndAddress;
+    E.SectionIndex = RLE.SectionIndex;
+    // Base address of a range list entry is determined by the closest preceding
+    // base address selection entry in the same range list. It defaults to the
+    // base address of the compilation unit if there is no such entry.
+    if (BaseAddr) {
+      E.LowPC += BaseAddr->Address;
+      E.HighPC += BaseAddr->Address;
+      if (E.SectionIndex == -1ULL)
+        E.SectionIndex = BaseAddr->SectionIndex;
+    }
+    Res.push_back(E);
+  }
+  return Res;
+}

lib/DebugInfo/DWARF/DWARFDebugRnglists.cpp

@@ -13,30 +13,19 @@
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/Format.h"
-#include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 
 Error RangeListEntry::extract(DWARFDataExtractor Data, uint32_t End,
-                              uint16_t Version, StringRef /* SectionName */,
-                              uint32_t *OffsetPtr, bool /* isDWO */) {
+                              uint32_t *OffsetPtr) {
   Offset = *OffsetPtr;
   SectionIndex = -1ULL;
-
-  assert((Data.getAddressSize() == 4 || Data.getAddressSize() == 8) &&
-         "Unsupported address size");
-
-  // We model a DWARF v4 range list entry like DWARF v5 DW_RLE_offset_pair,
-  // since it is subject to base adjustment.
-  uint8_t Encoding = dwarf::DW_RLE_offset_pair;
-  if (Version > 4) {
-    // The caller should guarantee that we have at least 1 byte available, so
-    // we just assert instead of revalidate.
-    assert(*OffsetPtr < End &&
-           "not enough space to extract a rangelist encoding");
-    Encoding = Data.getU8(OffsetPtr);
-  }
+  // The caller should guarantee that we have at least 1 byte available, so
+  // we just assert instead of revalidate.
+  assert(*OffsetPtr < End &&
+         "not enough space to extract a rangelist encoding");
+  uint8_t Encoding = Data.getU8(OffsetPtr);
 
   switch (Encoding) {
   case dwarf::DW_RLE_end_of_list:
@@ -59,23 +48,6 @@ Error RangeListEntry::extract(DWARFDataExtractor Data, uint32_t End,
                        "at offset 0x%" PRIx32,
                        *OffsetPtr - 1);
   case dwarf::DW_RLE_offset_pair: {
-    if (Version < 5) {
-      if ((End - *OffsetPtr) < unsigned(Data.getAddressSize() * 2))
-        return createStringError(
-            errc::illegal_byte_sequence,
-            "invalid range list entry at offset 0x%" PRIx32, *OffsetPtr);
-      Value0 = Data.getRelocatedAddress(OffsetPtr);
-      Value1 = Data.getRelocatedAddress(OffsetPtr, &SectionIndex);
-      // Adjust the EntryKind for end-of-list and base_address based on the
-      // contents.
-      if (Value0 == maxUIntN(Data.getAddressSize() * 8)) {
-        Encoding = dwarf::DW_RLE_base_address;
-        Value0 = Value1;
-        Value1 = 0;
-      } else if (Value0 == 0 && Value1 == 0)
-        Encoding = dwarf::DW_RLE_end_of_list;
-      break;
-    }
     uint32_t PreviousOffset = *OffsetPtr - 1;
     Value0 = Data.getULEB128(OffsetPtr);
     Value1 = Data.getULEB128(OffsetPtr);
@@ -86,7 +58,7 @@ Error RangeListEntry::extract(DWARFDataExtractor Data, uint32_t End,
                          PreviousOffset);
     break;
   }
-  case dwarf::DW_RLE_base_address:
+  case dwarf::DW_RLE_base_address: {
     if ((End - *OffsetPtr) < Data.getAddressSize())
       return createStringError(errc::invalid_argument,
                          "insufficient space remaining in table for "
@@ -94,16 +66,18 @@ Error RangeListEntry::extract(DWARFDataExtractor Data, uint32_t End,
                          *OffsetPtr - 1);
     Value0 = Data.getRelocatedAddress(OffsetPtr, &SectionIndex);
     break;
-  case dwarf::DW_RLE_start_end:
+  }
+  case dwarf::DW_RLE_start_end: {
     if ((End - *OffsetPtr) < unsigned(Data.getAddressSize() * 2))
       return createStringError(errc::invalid_argument,
                          "insufficient space remaining in table for "
                          "DW_RLE_start_end encoding "
                          "at offset 0x%" PRIx32,
                          *OffsetPtr - 1);
-    Value0 = Data.getRelocatedAddress(OffsetPtr);
-    Value1 = Data.getRelocatedAddress(OffsetPtr, &SectionIndex);
+    Value0 = Data.getRelocatedAddress(OffsetPtr, &SectionIndex);
+    Value1 = Data.getRelocatedAddress(OffsetPtr);
     break;
+  }
   case dwarf::DW_RLE_start_length: {
     uint32_t PreviousOffset = *OffsetPtr - 1;
     Value0 = Data.getRelocatedAddress(OffsetPtr, &SectionIndex);
@@ -169,10 +143,9 @@ DWARFAddressRangesVector DWARFDebugRnglist::getAbsoluteRanges(
   return Res;
 }
 
-void RangeListEntry::dump(raw_ostream &OS, DWARFContext *, uint8_t AddrSize,
-                          uint64_t &CurrentBase, unsigned Indent,
-                          uint16_t Version, uint8_t MaxEncodingStringLength,
-                          DIDumpOptions DumpOpts) const {
+void RangeListEntry::dump(raw_ostream &OS, uint8_t AddrSize,
+                          uint8_t MaxEncodingStringLength,
+                          uint64_t &CurrentBase, DIDumpOptions DumpOpts) const {
   auto PrintRawEntry = [](raw_ostream &OS, const RangeListEntry &Entry,
                           uint8_t AddrSize, DIDumpOptions DumpOpts) {
     if (DumpOpts.Verbose) {
@@ -183,49 +156,27 @@ void RangeListEntry::dump(raw_ostream &OS, DWARFContext *, uint8_t AddrSize,
     }
   };
 
-  // Output indentations before we print the actual entry. We only print
-  // anything for DW_RLE_base_address when we are in verbose mode.
-  if (DumpOpts.Verbose || !isBaseAddressSelectionEntry())
-    OS.indent(Indent);
-
   if (DumpOpts.Verbose) {
     // Print the section offset in verbose mode.
     OS << format("0x%8.8" PRIx32 ":", Offset);
-    if (Version > 4) {
-      auto EncodingString = dwarf::RangeListEncodingString(EntryKind);
-      // Unsupported encodings should have been reported during parsing.
-      assert(!EncodingString.empty() && "Unknown range entry encoding");
-      OS << format(" [%s%*c", EncodingString.data(),
-                   MaxEncodingStringLength - EncodingString.size() + 1, ']');
-      if (!isEndOfList())
-        OS << ": ";
-    }
+    auto EncodingString = dwarf::RangeListEncodingString(EntryKind);
+    // Unsupported encodings should have been reported during parsing.
+    assert(!EncodingString.empty() && "Unknown range entry encoding");
+    OS << format(" [%s%*c", EncodingString.data(),
+                 MaxEncodingStringLength - EncodingString.size() + 1, ']');
+    if (EntryKind != dwarf::DW_RLE_end_of_list)
+      OS << ": ";
   }
 
   switch (EntryKind) {
   case dwarf::DW_RLE_end_of_list:
-    if (DumpOpts.Verbose) {
-      // For DWARF v4 and earlier, we print the raw entry, i.e. 2 zeros.
-      if (Version < 5) {
-        OS << format(" 0x%*.*" PRIx64, AddrSize * 2, AddrSize * 2, Value0);
-        OS << format(", 0x%*.*" PRIx64, AddrSize * 2, AddrSize * 2, Value1);
-      }
-      break;
-    }
-    OS << "<End of list>";
+    OS << (DumpOpts.Verbose ? "" : "<End of list>");
     break;
   case dwarf::DW_RLE_base_address:
-    // In non-verbose mode, we do not print anything for this entry.
+    // In non-verbose mode we do not print anything for this entry.
     CurrentBase = Value0;
     if (!DumpOpts.Verbose)
       return;
-    if (Version < 5) {
-      // Dump the entry in pre-DWARF v5 format, i.e. with a -1 as Value0.
-      uint64_t allOnes = maxUIntN(AddrSize * 8);
-      OS << format(" 0x%*.*" PRIx64, AddrSize * 2, AddrSize * 2, allOnes);
-      OS << format(", 0x%*.*" PRIx64, AddrSize * 2, AddrSize * 2, Value0);
-      break;
-    }
     OS << format(" 0x%*.*" PRIx64, AddrSize * 2, AddrSize * 2, Value0);
     break;
   case dwarf::DW_RLE_start_length:

lib/DebugInfo/DWARF/DWARFDie.cpp

@@ -15,6 +15,7 @@
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"

lib/DebugInfo/DWARF/DWARFListTable.cpp

@@ -20,43 +20,30 @@ Error DWARFListTableHeader::extract(DWARFDataExtractor Data,
                                     uint32_t *OffsetPtr) {
   HeaderOffset = *OffsetPtr;
   // Read and verify the length field.
-  if (!Data.isValidOffsetForDataOfSize(*OffsetPtr, sizeof(uint32_t))) {
-    // By setting *OffsetPtr to 0, we indicate to the caller that 
-    // we could not detemine the length of the table.
-    *OffsetPtr = 0;
+  if (!Data.isValidOffsetForDataOfSize(*OffsetPtr, sizeof(uint32_t)))
     return createStringError(errc::invalid_argument,
                        "section is not large enough to contain a "
                        "%s table length at offset 0x%" PRIx32,
-                       SectionName.data(), HeaderOffset);
-  }
+                       SectionName.data(), *OffsetPtr);
   // TODO: Add support for DWARF64.
   HeaderData.Length = Data.getU32(OffsetPtr);
-  if (HeaderData.Length == 0xffffffffu) {
-    *OffsetPtr = 0;
+  if (HeaderData.Length == 0xffffffffu)
     return createStringError(errc::not_supported,
                        "DWARF64 is not supported in %s at offset 0x%" PRIx32,
                        SectionName.data(), HeaderOffset);
-  }
-
-  uint32_t TableLength = HeaderData.Length + sizeof(uint32_t);
-  uint32_t End = HeaderOffset + TableLength;
   Format = dwarf::DwarfFormat::DWARF32;
-  if (TableLength < sizeof(Header)) {
-    *OffsetPtr = End;
-    return createStringError(
-        errc::invalid_argument,
-        "%s table at offset 0x%" PRIx32 " has too small length (0x%" PRIx32
-        ") to contain a complete header",
-        SectionName.data(), HeaderOffset, TableLength);
-  }
-  if (!Data.isValidOffsetForDataOfSize(HeaderOffset, TableLength)) {
-    *OffsetPtr = 0;   // No recovery if the length exceeds the section size.
-    return createStringError(
-        errc::invalid_argument,
-        "section is not large enough to contain a %s table "
-        "of length 0x%" PRIx32 " at offset 0x%" PRIx32,
-        SectionName.data(), TableLength, HeaderOffset);
-  }
+  if (HeaderData.Length + sizeof(uint32_t) < sizeof(Header))
+    return createStringError(errc::invalid_argument,
+                       "%s table at offset 0x%" PRIx32
+                       " has too small length (0x%" PRIx32
+                       ") to contain a complete header",
+                       SectionName.data(), HeaderOffset, length());
+  uint32_t End = HeaderOffset + length();
+  if (!Data.isValidOffsetForDataOfSize(HeaderOffset, End - HeaderOffset))
+    return createStringError(errc::invalid_argument,
+                       "section is not large enough to contain a %s table "
+                       "of length 0x%" PRIx32 " at offset 0x%" PRIx32,
+                       SectionName.data(), length(), HeaderOffset);
 
   HeaderData.Version = Data.getU16(OffsetPtr);
   HeaderData.AddrSize = Data.getU8(OffsetPtr);
@@ -64,36 +51,27 @@ Error DWARFListTableHeader::extract(DWARFDataExtractor Data,
   HeaderData.OffsetEntryCount = Data.getU32(OffsetPtr);
 
   // Perform basic validation of the remaining header fields.
-  if (HeaderData.Version != 5) {
-    *OffsetPtr = End;
+  if (HeaderData.Version != 5)
     return createStringError(errc::invalid_argument,
-                             "unrecognised %s table version %" PRIu16
-                             " in table at offset 0x%" PRIx32,
-                             SectionName.data(), HeaderData.Version,
-                             HeaderOffset);
-  }
-  if (HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8) {
-    *OffsetPtr = End;
+                       "unrecognised %s table version %" PRIu16
+                       " in table at offset 0x%" PRIx32,
+                       SectionName.data(), HeaderData.Version, HeaderOffset);
+  if (HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8)
     return createStringError(errc::not_supported,
                        "%s table at offset 0x%" PRIx32
                        " has unsupported address size %" PRIu8,
                        SectionName.data(), HeaderOffset, HeaderData.AddrSize);
-  }
-  if (HeaderData.SegSize != 0) {
-    *OffsetPtr = End;
+  if (HeaderData.SegSize != 0)
     return createStringError(errc::not_supported,
                        "%s table at offset 0x%" PRIx32
                        " has unsupported segment selector size %" PRIu8,
                        SectionName.data(), HeaderOffset, HeaderData.SegSize);
-  }
   if (End < HeaderOffset + sizeof(HeaderData) +
-                HeaderData.OffsetEntryCount * sizeof(uint32_t)) {
-    *OffsetPtr = End;
+                HeaderData.OffsetEntryCount * sizeof(uint32_t))
     return createStringError(errc::invalid_argument,
         "%s table at offset 0x%" PRIx32 " has more offset entries (%" PRIu32
         ") than there is space for",
         SectionName.data(), HeaderOffset, HeaderData.OffsetEntryCount);
-  }
   Data.setAddressSize(HeaderData.AddrSize);
   for (uint32_t I = 0; I < HeaderData.OffsetEntryCount; ++I)
     Offsets.push_back(Data.getU32(OffsetPtr));
@@ -123,11 +101,9 @@ void DWARFListTableHeader::dump(raw_ostream &OS, DIDumpOptions DumpOpts) const {
   }
 }
 
-uint32_t DWARFListTableHeader::getTableLength() const {
+uint32_t DWARFListTableHeader::length() const {
   if (HeaderData.Length == 0)
     return 0;
-  assert(HeaderData.Version > 0 &&
-         "No DWARF version in header when using getTableLength()");
   // TODO: DWARF64 support.
-  return HeaderData.Length + (HeaderData.Version > 4) * sizeof(uint32_t);
+  return HeaderData.Length + sizeof(uint32_t);
 }

lib/DebugInfo/DWARF/DWARFUnit.cpp

@@ -264,16 +264,13 @@ bool DWARFUnitHeader::extract(DWARFContext &Context,
   return true;
 }
 
-// Parse a list table header, including the optional array of offsets
+// Parse the rangelist table header, including the optional array of offsets
 // following it (DWARF v5 and later).
-template <typename DWARFListTable>
-static Expected<DWARFListTable>
-parseListTableHeader(DWARFDataExtractor DA, DWARFContext *C,
-                     StringRef SectionName, uint32_t Offset, bool isDWO) {
+static Expected<DWARFDebugRnglistTable>
+parseRngListTableHeader(DWARFDataExtractor &DA, uint32_t Offset) {
   // TODO: Support DWARF64
   // We are expected to be called with Offset 0 or pointing just past the table
   // header, which is 12 bytes long for DWARF32.
-  DWARFListTable Table(C, SectionName, isDWO);
   if (Offset > 0) {
     if (Offset < 12U)
       return createStringError(errc::invalid_argument, "Did not detect a valid"
@@ -281,46 +278,20 @@ parseListTableHeader(DWARFDataExtractor DA, DWARFContext *C,
                                Offset);
     Offset -= 12U;
   }
+  llvm::DWARFDebugRnglistTable Table;
   if (Error E = Table.extractHeaderAndOffsets(DA, &Offset))
     return std::move(E);
   return Table;
 }
 
-// Parse a DWARF v5 list table (e.g. either a rangelist table or a location
-// list table). For DWARF units with version 4 or earlier, we instead create
-// the table artifically by giving it a size that equals the section size.
-template <typename DWARFListTable>
-static Optional<DWARFListTable>
-setupListTable(DWARFUnit *U, const DWARFSection *Section, StringRef SectionName,
-               uint32_t &Base, bool isDWO, bool isLittleEndian) {
-  if (!Section->Data.size())
-    return None;
-  DWARFContext &Ctx = U->getContext();
-  DWARFListTable Table(&Ctx, SectionName, isDWO);
-  // Parse the list table header. Individual lists are extracted lazily.
-  DWARFDataExtractor DA(Ctx.getDWARFObj(), *Section, isLittleEndian,
-                        U->getAddressByteSize());
-  if (U->getVersion() < 5) {
-    Base = 0;
-    Table.setHeaderData(Section->Data.size(), U->getVersion(),
-                        DA.getAddressSize());
-    return Table;
-  }
-  if (auto TableOrError = parseListTableHeader<DWARFListTable>(
-          DA, &Ctx, SectionName, Base, isDWO))
-    Table = TableOrError.get();
-  else {
-    WithColor::error() << "parsing a " << Table.getListTypeString().data()
-                       << " list table: " << toString(TableOrError.takeError())
-                       << '\n';
-    return None;
-  }
-  // In a split dwarf unit, there are no attributes like DW_AT_rnglists_base or
-  // DW_AT_loclists_base that describe the table base. Adjust Base to point past
-  // the table header which is expected to start at offset 0.
-  if (isDWO)
-    Base = Table.getHeaderSize();
-  return Table;
+Error DWARFUnit::extractRangeList(uint32_t RangeListOffset,
+                                  DWARFDebugRangeList &RangeList) const {
+  // Require that compile unit is extracted.
+  assert(!DieArray.empty());
+  DWARFDataExtractor RangesData(Context.getDWARFObj(), *RangeSection,
+                                isLittleEndian, getAddressByteSize());
+  uint32_t ActualRangeListOffset = RangeSectionBase + RangeListOffset;
+  return RangeList.extract(RangesData, &ActualRangeListOffset);
 }
 
 void DWARFUnit::clear() {
@@ -440,20 +411,31 @@ size_t DWARFUnit::extractDIEsIfNeeded(bool CUDieOnly) {
 
     // DWARF v5 uses the .debug_rnglists and .debug_rnglists.dwo sections to
     // describe address ranges.
-    StringRef RangeSectionName = ".debug_ranges";
     if (getVersion() >= 5) {
-      if (isDWO) {
-        RangeSectionName = ".debug_rnglists.dwo";
+      if (isDWO)
         setRangesSection(&Context.getDWARFObj().getRnglistsDWOSection(), 0);
-      } else {
-        RangeSectionName = ".debug_rnglists";
+      else
         setRangesSection(&Context.getDWARFObj().getRnglistsSection(),
                          toSectionOffset(UnitDie.find(DW_AT_rnglists_base), 0));
+      if (RangeSection->Data.size()) {
+        // Parse the range list table header. Individual range lists are
+        // extracted lazily.
+        DWARFDataExtractor RangesDA(Context.getDWARFObj(), *RangeSection,
+                                    isLittleEndian, 0);
+        if (auto TableOrError =
+                parseRngListTableHeader(RangesDA, RangeSectionBase))
+          RngListTable = TableOrError.get();
+        else
+          WithColor::error() << "parsing a range list table: "
+                             << toString(TableOrError.takeError())
+                             << '\n';
+
+        // In a split dwarf unit, there is no DW_AT_rnglists_base attribute.
+        // Adjust RangeSectionBase to point past the table header.
+        if (isDWO && RngListTable)
+          RangeSectionBase = RngListTable->getHeaderSize();
       }
     }
-    RngListTable = setupListTable<DWARFDebugRnglistTable>(
-        this, RangeSection, RangeSectionName, RangeSectionBase, isDWO,
-        isLittleEndian);
 
     // Don't fall back to DW_AT_GNU_ranges_base: it should be ignored for
     // skeleton CU DIE, so that DWARF users not aware of it are not broken.
@@ -495,9 +477,16 @@ bool DWARFUnit::parseDWO() {
   DWO->setAddrOffsetSection(AddrOffsetSection, AddrOffsetSectionBase);
   if (getVersion() >= 5) {
     DWO->setRangesSection(&Context.getDWARFObj().getRnglistsDWOSection(), 0);
-    DWO->RngListTable = setupListTable<DWARFDebugRnglistTable>(
-        DWOCU, DWO->RangeSection, ".debug_rnglists.dwo", DWO->RangeSectionBase,
-        /* isDWO =*/true, isLittleEndian);
+    DWARFDataExtractor RangesDA(Context.getDWARFObj(), *RangeSection,
+                                isLittleEndian, 0);
+    if (auto TableOrError = parseRngListTableHeader(RangesDA, RangeSectionBase))
+      DWO->RngListTable = TableOrError.get();
+    else
+      WithColor::error() << "parsing a range list table: "
+                         << toString(TableOrError.takeError())
+                         << '\n';
+    if (DWO->RngListTable)
+      DWO->RangeSectionBase = DWO->RngListTable->getHeaderSize();
   } else {
     auto DWORangesBase = UnitDie.getRangesBaseAttribute();
     DWO->setRangesSection(RangeSection, DWORangesBase ? *DWORangesBase : 0);
@@ -515,6 +504,12 @@ void DWARFUnit::clearDIEs(bool KeepCUDie) {
 
 Expected<DWARFAddressRangesVector>
 DWARFUnit::findRnglistFromOffset(uint32_t Offset) {
+  if (getVersion() <= 4) {
+    DWARFDebugRangeList RangeList;
+    if (Error E = extractRangeList(Offset, RangeList))
+      return std::move(E);
+    return RangeList.getAbsoluteRanges(getBaseAddress());
+  }
   if (RngListTable) {
     DWARFDataExtractor RangesData(Context.getDWARFObj(), *RangeSection,
                                   isLittleEndian, RngListTable->getAddrSize());

test/DebugInfo/Generic/cu-ranges.ll

@@ -4,18 +4,18 @@
 
 ; Check that we emit ranges for this which has a non-traditional section and a normal section.
 
-; CHECK:      .debug_info contents:
-; CHECK:      DW_TAG_compile_unit
-; CHECK-NOT:  DW_TAG
-; CHECK:      DW_AT_ranges [DW_FORM_sec_offset] (0x
-; CHECK-NEXT: [0x{{[0-9A-Fa-f]+}}, 0x{{[0-9A-Fa-f]+}})
-; CHECK-NEXT: [0x{{[0-9A-Fa-f]+}}, 0x{{[0-9A-Fa-f]+}}){{.*}})
-; CHECK:      DW_TAG_subprogram
-; CHECK:      DW_AT_low_pc
-; CHECK:      DW_AT_high_pc
-; CHECK:      DW_TAG_subprogram
-; CHECK:      DW_AT_low_pc
-; CHECK:      DW_AT_high_pc
+; CHECK: DW_TAG_compile_unit
+; CHECK: DW_AT_ranges
+; CHECK: DW_TAG_subprogram
+; CHECK: DW_AT_low_pc
+; CHECK: DW_AT_high_pc
+; CHECK: DW_TAG_subprogram
+; CHECK: DW_AT_low_pc
+; CHECK: DW_AT_high_pc
+
+; CHECK: .debug_ranges contents:
+; FIXME: When we get better dumping facilities we'll want to elaborate here.
+; CHECK: 00000000 <End of list>
 
 ; Function Attrs: nounwind uwtable
 define i32 @foo(i32 %a) #0 section "__TEXT,__foo" !dbg !4 {

test/DebugInfo/Inputs/gmlt.ll

@@ -83,7 +83,7 @@
 ; written in relocation places (dumper needs to	be fixed to read the
 ; relocations rather than interpret that as the end of a range list))
 
-; CHECK: 0x{{[0-9A-Fa-f]+}}: 0x{{0+}}, 0x{{0+}}
+; CHECK: 00000000 <End of list>
 
 
 ; Check that we don't emit any pubnames or pubtypes under -gmlt

test/DebugInfo/X86/dwarfdump-ranges-baseaddr.s

@@ -1,6 +1,5 @@
 # RUN: llvm-mc -triple x86_64-pc-linux -filetype=obj %s -o %t
 # RUN: llvm-dwarfdump -v %t 2>%t.err | FileCheck %s
-# RUN: llvm-dwarfdump --debug-ranges %t | FileCheck --check-prefix=TERSE %s
 # RUN: FileCheck %s <%t.err -check-prefix=ERR
 
 # CHECK: .debug_info contents:
@@ -11,24 +10,6 @@
 # CHECK-NEXT:    [0x0000000000000003, 0x0000000000000006) ".text"
 # CHECK-NEXT:    [0x0000000000000001, 0x0000000000000002) ".text.foo1")
 
-# CHECK:      .debug_ranges contents:
-# CHECK-NEXT: 0x00000000: 0x0000000000000000, 0x0000000000000001 =>
-# CHECK-SAME: [0x0000000000000000, 0x0000000000000001)
-# CHECK-NEXT: 0x00000010: 0x0000000000000003, 0x0000000000000006 =>
-# CHECK-SAME: [0x0000000000000003, 0x0000000000000006)
-# CHECK-NEXT: 0x00000020: 0xffffffffffffffff, 0x0000000000000000
-# CHECK-NEXT: 0x00000030: 0x0000000000000001, 0x0000000000000002 =>
-# CHECK-SAME: [0x0000000000000001, 0x0000000000000002)
-# CHECK-NEXT: 0x00000040: 0x0000000000000000, 0x0000000000000000
-
-# TERSE:      .debug_ranges contents:
-# TERSE-NEXT: [0x0000000000000000, 0x0000000000000001)
-# TERSE-NEXT: [0x0000000000000003, 0x0000000000000006)
-# TERSE-NEXT: [0x0000000000000001, 0x0000000000000002)
-# TERSE-NEXT: <End of list>
-
-
-
 .text
 .globl foo
 .type foo,@function

test/DebugInfo/X86/dwarfdump-ranges-unrelocated.s

@@ -9,13 +9,10 @@
 # CHECK-NEXT:  [0x0000000000000000, 0x0000000000000003) ".text.foo2" [5])
 
 # CHECK: .debug_ranges contents:
-# CHECK-NEXT: 0x00000000: 0x0000000000000000, 0x0000000000000001 =>
-# CHECK-SAME: [0x0000000000000000, 0x0000000000000001)
-# CHECK-NEXT: 0x00000010: 0x0000000000000000, 0x0000000000000002 =>
-# CHECK-SAME: [0x0000000000000000, 0x0000000000000002)
-# CHECK-NEXT: 0x00000020: 0x0000000000000000, 0x0000000000000003 =>
-# CHECK-SAME: [0x0000000000000000, 0x0000000000000003)
-# CHCKK-NEXT: 0x00000030: 0x0000000000000000, 0x0000000000000000
+# CHECK:   00000000 0000000000000000 0000000000000001
+# CHECK:   00000000 0000000000000000 0000000000000002
+# CHECK:   00000000 0000000000000000 0000000000000003
+# CHECK:   00000000 <End of list>
 
 # RUN: llvm-dwarfdump %t | FileCheck %s --check-prefix=BRIEF
 # BRIEF: DW_TAG_compile_unit

test/DebugInfo/dwarfdump-ranges.test

@@ -1,5 +1,4 @@
 RUN: llvm-dwarfdump -v %p/Inputs/dwarfdump-test4.elf-x86-64 | FileCheck %s
-RUN: llvm-dwarfdump --debug-ranges %p/Inputs/dwarfdump-test4.elf-x86-64 | FileCheck -check-prefix=TERSE %s
 
 CHECK: .debug_info contents:
 CHECK: DW_TAG_compile_unit
@@ -16,21 +15,10 @@ CHECK-NEXT:          [0x0000000000000637, 0x000000000000063d))
 
 
 CHECK:      .debug_ranges contents:
-CHECK-NEXT: 0x00000000: 0x000000000000062c, 0x0000000000000637 =>
-CHECK-SAME: [0x000000000000062c, 0x0000000000000637)
-CHECK-NEXT: 0x00000010: 0x0000000000000637, 0x000000000000063d =>
-CHECK-SAME: [0x0000000000000637, 0x000000000000063d)
-CHECK-NEXT: 0x00000020: 0x0000000000000000, 0x0000000000000000
-CHECK-NEXT: 0x00000030: 0x0000000000000640, 0x000000000000064b =>
-CHECK-SAME: [0x0000000000000640, 0x000000000000064b)
-CHECK-NEXT: 0x00000040: 0x0000000000000637, 0x000000000000063d =>
-CHECK-SAME: [0x0000000000000637, 0x000000000000063d)
-CHECK-NEXT: 0x00000050: 0x0000000000000000, 0x0000000000000000
+CHECK-NEXT: 00000000 000000000000062c 0000000000000637
+CHECK-NEXT: 00000000 0000000000000637 000000000000063d
+CHECK-NEXT: 00000000 <End of list>
+CHECK-NEXT: 00000030 0000000000000640 000000000000064b
+CHECK-NEXT: 00000030 0000000000000637 000000000000063d
+CHECK-NEXT: 00000030 <End of list>
 
-TERSE:      .debug_ranges contents:
-TERSE-NEXT: [0x000000000000062c, 0x0000000000000637)
-TERSE-NEXT: [0x0000000000000637, 0x000000000000063d)
-TERSE-NEXT: <End of list>
-TERSE-NEXT: [0x0000000000000640, 0x000000000000064b)
-TERSE-NEXT: [0x0000000000000637, 0x000000000000063d)
-TERSE-NEXT: <End of list>

test/MC/ARM/dwarf-asm-multiple-sections.s

@@ -64,11 +64,12 @@ b:
 
 
 // DWARF: .debug_ranges contents:
-// DWARF-NEXT: 0x00000000: 0xffffffff, 0x00000000
-// DWARF-NEXT: 0x00000008: 0x00000000, 0x00000004 => [0x00000000, 0x00000004)
-// DWARF-NEXT: 0x00000010: 0xffffffff, 0x00000000
-// DWARF-NEXT: 0x00000018: 0x00000000, 0x00000004 => [0x00000000, 0x00000004)
-// DWARF-NEXT: 0x00000020: 0x00000000, 0x00000000
+// DWARF: 00000000 ffffffff 00000000
+// DWARF: 00000000 00000000 00000004
+// DWARF: 00000000 ffffffff 00000000
+// DWARF: 00000000 00000000 00000004
+// DWARF: 00000000 <End of list>
+
 
 
 // Offsets are different in DWARF v5 due to different header layout.

tools/dsymutil/DwarfLinker.cpp

@@ -43,6 +43,7 @@
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFSection.h"
@@ -1575,7 +1576,7 @@ DIE *DwarfLinker::DIECloner::cloneDIE(const DWARFDie &InputDIE,
 void DwarfLinker::patchRangesForUnit(const CompileUnit &Unit,
                                      DWARFContext &OrigDwarf,
                                      const DebugMapObject &DMO) const {
-  DWARFDebugRnglist RangeList;
+  DWARFDebugRangeList RangeList;
   const auto &FunctionRanges = Unit.getFunctionRanges();
   unsigned AddressSize = Unit.getOrigUnit().getAddressByteSize();
   DWARFDataExtractor RangeExtractor(OrigDwarf.getDWARFObj(),
@@ -1595,30 +1596,28 @@ void DwarfLinker::patchRangesForUnit(const CompileUnit &Unit,
   for (const auto &RangeAttribute : Unit.getRangesAttributes()) {
     uint32_t Offset = RangeAttribute.get();
     RangeAttribute.set(Streamer->getRangesSectionSize());
-    if (Error E = RangeList.extract(RangeExtractor, /* HeaderOffset = */0,
-                                    RangeExtractor.size(),
-                                    Unit.getOrigUnit().getVersion(), &Offset,
-                                    ".debug_ranges", "range")) {
+    if (Error E = RangeList.extract(RangeExtractor, &Offset)) {
       llvm::consumeError(std::move(E));
       reportWarning("invalid range list ignored.", DMO);
       RangeList.clear();
     }
     const auto &Entries = RangeList.getEntries();
-    if (!RangeList.empty()) {
-      const auto &First = Entries.front();
+    if (!Entries.empty()) {
+      const DWARFDebugRangeList::RangeListEntry &First = Entries.front();
+
       if (CurrRange == InvalidRange ||
-          First.getStartAddress() + OrigLowPc < CurrRange.start() ||
-          First.getStartAddress() + OrigLowPc >= CurrRange.stop()) {
-        CurrRange = FunctionRanges.find(First.getStartAddress() + OrigLowPc);
+          First.StartAddress + OrigLowPc < CurrRange.start() ||
+          First.StartAddress + OrigLowPc >= CurrRange.stop()) {
+        CurrRange = FunctionRanges.find(First.StartAddress + OrigLowPc);
         if (CurrRange == InvalidRange ||
-            CurrRange.start() > First.getStartAddress() + OrigLowPc) {
+            CurrRange.start() > First.StartAddress + OrigLowPc) {
           reportWarning("no mapping for range.", DMO);
           continue;
         }
       }
     }
 
-    Streamer->emitRangesEntries(UnitPcOffset, OrigLowPc, CurrRange, RangeList,
+    Streamer->emitRangesEntries(UnitPcOffset, OrigLowPc, CurrRange, Entries,
                                 AddressSize);
   }
 }

tools/dsymutil/DwarfStreamer.cpp

@@ -269,27 +269,28 @@ void DwarfStreamer::emitSwiftAST(StringRef Buffer) {
 void DwarfStreamer::emitRangesEntries(
     int64_t UnitPcOffset, uint64_t OrigLowPc,
     const FunctionIntervals::const_iterator &FuncRange,
-    const DWARFDebugRnglist &RangeList, unsigned AddressSize) {
+    const std::vector<DWARFDebugRangeList::RangeListEntry> &Entries,
+    unsigned AddressSize) {
   MS->SwitchSection(MC->getObjectFileInfo()->getDwarfRangesSection());
 
   // Offset each range by the right amount.
-  int64_t PcOffset = RangeList.empty() ? 0 : FuncRange.value() + UnitPcOffset;
-  for (const auto &Range : RangeList.getEntries()) {
-    if (Range.isBaseAddressSelectionEntry()) {
+  int64_t PcOffset = Entries.empty() ? 0 : FuncRange.value() + UnitPcOffset;
+  for (const auto &Range : Entries) {
+    if (Range.isBaseAddressSelectionEntry(AddressSize)) {
       warn("unsupported base address selection operation",
            "emitting debug_ranges");
       break;
     }
     // Do not emit empty ranges.
-    if (Range.isEndOfList() || Range.getStartAddress() == Range.getEndAddress())
+    if (Range.StartAddress == Range.EndAddress)
       continue;
 
     // All range entries should lie in the function range.
-    if (!(Range.getStartAddress() + OrigLowPc >= FuncRange.start() &&
-          Range.getEndAddress() + OrigLowPc <= FuncRange.stop()))
+    if (!(Range.StartAddress + OrigLowPc >= FuncRange.start() &&
+          Range.EndAddress + OrigLowPc <= FuncRange.stop()))
       warn("inconsistent range data.", "emitting debug_ranges");
-    MS->EmitIntValue(Range.getStartAddress() + PcOffset, AddressSize);
-    MS->EmitIntValue(Range.getEndAddress() + PcOffset, AddressSize);
+    MS->EmitIntValue(Range.StartAddress + PcOffset, AddressSize);
+    MS->EmitIntValue(Range.EndAddress + PcOffset, AddressSize);
     RangesSectionSize += 2 * AddressSize;
   }
 

tools/dsymutil/DwarfStreamer.h

@@ -17,7 +17,7 @@
 #include "llvm/CodeGen/AccelTable.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
-#include "llvm/DebugInfo/DWARF/DWARFDebugRnglists.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/MC/MCAsmBackend.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCCodeEmitter.h"
@@ -83,7 +83,7 @@ public:
   void emitRangesEntries(
       int64_t UnitPcOffset, uint64_t OrigLowPc,
       const FunctionIntervals::const_iterator &FuncRange,
-      const DWARFDebugRnglist &RangeList,
+      const std::vector<DWARFDebugRangeList::RangeListEntry> &Entries,
       unsigned AddressSize);
 
   /// Emit debug_aranges entries for \p Unit and if \p DoRangesSection is true,