[DWARF][NFC] Refactor range list extraction and dumping

The purpose of this patch is twofold: 
- Fold pre-DWARF v5 functionality into v5 to eliminate the need for 2 different 
  versions of range list handling. We get rid of DWARFDebugRangelist{.cpp,.h}.
- Templatize the handling of range list tables so that location list handling
  can take advantage of it as well. Location list and range list tables have the 
  same basic layout.

A non-NFC version of this patch was previously submitted with r342218, but it caused
errors with some TSan tests. This patch has no functional changes. The difference to
the non-NFC patch is that there are no changes to rangelist dumping in this patch.

Differential Revision: https://reviews.llvm.org/D53545

llvm-svn: 345546

llvm/include/llvm/DebugInfo/DWARF/DWARFContext.h

@@ -231,16 +231,16 @@ class DWARFContext : public DIContext {
   /// Get a DIE given an exact offset.
   DWARFDie getDIEForOffset(uint32_t Offset);
 
-  unsigned getMaxVersion() {
+  unsigned getMaxVersion(uint16_t DefaultVersion = 0) {
     // Ensure info units have been parsed to discover MaxVersion
     info_section_units();
-    return MaxVersion;
+    return MaxVersion ? MaxVersion : DefaultVersion;
   }
 
-  unsigned getMaxDWOVersion() {
+  unsigned getMaxDWOVersion(uint16_t DefaultVersion = 0) {
     // Ensure DWO info units have been parsed to discover MaxVersion
     dwo_info_section_units();
-    return MaxVersion;
+    return MaxVersion ? MaxVersion : DefaultVersion;
   }
 
   void setMaxVersionIfGreater(unsigned Version) {

llvm/include/llvm/DebugInfo/DWARF/DWARFDebugRnglists.h

@@ -13,15 +13,17 @@
 #include "llvm/ADT/Optional.h"
 #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>
 #include <vector>
 
 namespace llvm {
 
+struct BaseAddress;
+class DWARFContext;
 class Error;
 class raw_ostream;
 class DWARFUnit;
@@ -35,12 +37,30 @@ struct RangeListEntry : public DWARFListEntryBase {
   uint64_t Value0;
   uint64_t Value1;
 
-  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,
+  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, DIDumpOptions DumpOpts,
             llvm::function_ref<Optional<SectionedAddress>(uint32_t)>
                 LookupPooledAddress) const;
-  bool isSentinel() const { return EntryKind == dwarf::DW_RLE_end_of_list; }
 };
 
 /// A class representing a single rangelist.
@@ -54,10 +74,12 @@ class DWARFDebugRnglist : public DWARFListType<RangeListEntry> {
 
 class DWARFDebugRnglistTable : public DWARFListTableBase<DWARFDebugRnglist> {
 public:
-  DWARFDebugRnglistTable()
-      : DWARFListTableBase(/* SectionName    = */ ".debug_rnglists",
+  DWARFDebugRnglistTable(DWARFContext *C, StringRef SectionName,
+                         bool isDWO = false)
+      : DWARFListTableBase(C, SectionName, isDWO,
                            /* HeaderString   = */ "ranges:",
-                           /* ListTypeString = */ "range") {}
+                           /* ListTypeString = */ "range",
+                           dwarf::RangeListEncodingString) {}
 };
 
 } // end namespace llvm