[DWARFYAML] Replace InitialLength with Format and Length. NFC.

[Higuoxing]

Summary

This change replaces the InitialLength of pub-tables with Format and
Length. All the InitialLength fields have been removed.

[jhenderson]

Nice! Do we have/need any DWARF64 testing for the pubnames etc tables?

[Higuoxing]

Test DWARF64 pub-tables.

[Higuoxing]

In D85880#2215006, @jhenderson wrote:

Nice! Do we have/need any DWARF64 testing for the pubnames etc tables?

Originally, yaml2obj doesn't support emitting DWARF64 pub-tables. I've slightly modified the DWARF emitter and added a bunch of tests. I'm afraid it will bring difficulty in reviewing this change. Shall I add them in a separate patch?

[jhenderson]

In D85880#2215089, @Higuoxing wrote:

In D85880#2215006, @jhenderson wrote:

Nice! Do we have/need any DWARF64 testing for the pubnames etc tables?

Originally, yaml2obj doesn't support emitting DWARF64 pub-tables. I've slightly modified the DWARF emitter and added a bunch of tests. I'm afraid it will bring difficulty in reviewing this change. Shall I add them in a separate patch?

Ah, I didn't realise it didn't support it. Let's split off support to a separate patch.

[Higuoxing]

Revert to previous version.

[Higuoxing]

Revert changes in DWARFEmitter.cpp

[jhenderson]

LGTM!

llvm/include/llvm/ObjectYAML/DWARFYAML.h

 #include "llvm/ObjectYAML/YAML.h"
 #include "llvm/Support/YAMLTraits.h"
 #include <cstdint>
 #include <vector>
 
 namespace llvm {
 namespace DWARFYAML {
 
-struct InitialLength {
-  uint32_t TotalLength;
-  uint64_t TotalLength64;
-
-  bool isDWARF64() const { return TotalLength == UINT32_MAX; }
-
-  uint64_t getLength() const {
-    return isDWARF64() ? TotalLength64 : TotalLength;
-  }
-
-  void setLength(uint64_t Len) {
-    if (Len >= (uint64_t)UINT32_MAX) {
-      TotalLength64 = Len;
-      TotalLength = UINT32_MAX;
-    } else {
-      TotalLength = Len;
-    }
-  }
-};
-
 struct AttributeAbbrev {
   llvm::dwarf::Attribute Attribute;
   llvm::dwarf::Form Form;
   llvm::yaml::Hex64 Value; // Some DWARF5 attributes have values
 };
 
 struct Abbrev {
   Optional<yaml::Hex64> Code;

 
 struct PubEntry {
   llvm::yaml::Hex32 DieOffset;
   llvm::yaml::Hex8 Descriptor;
   StringRef Name;
 };
 
 struct PubSection {
-  InitialLength Length;
+  dwarf::DwarfFormat Format;
+  yaml::Hex64 Length;
   uint16_t Version;
   uint32_t UnitOffset;
   uint32_t UnitSize;
   std::vector<PubEntry> Entries;
 };
 
 struct FormValue {
   llvm::yaml::Hex64 Value;

 template <> struct MappingTraits<DWARFYAML::AddrTableEntry> {
   static void mapping(IO &IO, DWARFYAML::AddrTableEntry &AddrTable);
 };
 
 template <> struct MappingTraits<DWARFYAML::StringOffsetsTable> {
   static void mapping(IO &IO, DWARFYAML::StringOffsetsTable &StrOffsetsTable);
 };
 
-template <> struct MappingTraits<DWARFYAML::InitialLength> {
-  static void mapping(IO &IO, DWARFYAML::InitialLength &DWARF);
-};
-
 template <> struct ScalarEnumerationTraits<dwarf::DwarfFormat> {
   static void enumeration(IO &IO, dwarf::DwarfFormat &Format) {
     IO.enumCase(Format, "DWARF32", dwarf::DWARF32);
     IO.enumCase(Format, "DWARF64", dwarf::DWARF64);
   }
 };
 
 #define HANDLE_DW_TAG(unused, name, unused2, unused3, unused4)                 \

llvm/lib/ObjectYAML/DWARFEmitter.cpp

 }
 
 static void ZeroFillBytes(raw_ostream &OS, size_t Size) {
   std::vector<uint8_t> FillData;
   FillData.insert(FillData.begin(), Size, 0);
   OS.write(reinterpret_cast<char *>(FillData.data()), Size);
 }
 
-static void writeInitialLength(const DWARFYAML::InitialLength &Length,
-                               raw_ostream &OS, bool IsLittleEndian) {
-  writeInteger((uint32_t)Length.TotalLength, OS, IsLittleEndian);
-  if (Length.isDWARF64())
-    writeInteger((uint64_t)Length.TotalLength64, OS, IsLittleEndian);
-}
-
 static void writeInitialLength(const dwarf::DwarfFormat Format,
                                const uint64_t Length, raw_ostream &OS,
                                bool IsLittleEndian) {
   bool IsDWARF64 = Format == dwarf::DWARF64;
   if (IsDWARF64)
     cantFail(writeVariableSizedInteger(dwarf::DW_LENGTH_DWARF64, 4, OS,
                                        IsLittleEndian));
   cantFail(
for (auto DebugRanges : DI.DebugRanges) {
     ++EntryIndex;
   }
 
   return Error::success();
 }
 
 static Error emitPubSection(raw_ostream &OS, const DWARFYAML::PubSection &Sect,
                             bool IsLittleEndian, bool IsGNUPubSec = false) {
-  writeInitialLength(Sect.Length, OS, IsLittleEndian);
+  writeInitialLength(Sect.Format, Sect.Length, OS, IsLittleEndian);
   writeInteger((uint16_t)Sect.Version, OS, IsLittleEndian);
   writeInteger((uint32_t)Sect.UnitOffset, OS, IsLittleEndian);
   writeInteger((uint32_t)Sect.UnitSize, OS, IsLittleEndian);
   for (auto Entry : Sect.Entries) {
     writeInteger((uint32_t)Entry.DieOffset, OS, IsLittleEndian);
     if (IsGNUPubSec)
       writeInteger((uint8_t)Entry.Descriptor, OS, IsLittleEndian);
     OS.write(Entry.Name.data(), Entry.Name.size());

llvm/lib/ObjectYAML/DWARFYAML.cpp

void MappingTraits<DWARFYAML::PubEntry>::mapping(IO &IO,
   IO.mapRequired("DieOffset", Entry.DieOffset);
   if (static_cast<DWARFYAML::DWARFContext *>(IO.getContext())->IsGNUPubSec)
     IO.mapRequired("Descriptor", Entry.Descriptor);
   IO.mapRequired("Name", Entry.Name);
 }
 
 void MappingTraits<DWARFYAML::PubSection>::mapping(
     IO &IO, DWARFYAML::PubSection &Section) {
+  IO.mapOptional("Format", Section.Format, dwarf::DWARF32);
   IO.mapRequired("Length", Section.Length);
   IO.mapRequired("Version", Section.Version);
   IO.mapRequired("UnitOffset", Section.UnitOffset);
   IO.mapRequired("UnitSize", Section.UnitSize);
   IO.mapRequired("Entries", Section.Entries);
 }
 
 void MappingTraits<DWARFYAML::Unit>::mapping(IO &IO, DWARFYAML::Unit &Unit) {
void MappingTraits<DWARFYAML::ListTable<EntryType>>::mapping(
   IO.mapOptional("Version", ListTable.Version, 5);
   IO.mapOptional("AddressSize", ListTable.AddrSize);
   IO.mapOptional("SegmentSelectorSize", ListTable.SegSelectorSize, 0);
   IO.mapOptional("OffsetEntryCount", ListTable.OffsetEntryCount);
   IO.mapOptional("Offsets", ListTable.Offsets);
   IO.mapOptional("Lists", ListTable.Lists);
 }
 
-void MappingTraits<DWARFYAML::InitialLength>::mapping(
-    IO &IO, DWARFYAML::InitialLength &InitialLength) {
-  IO.mapRequired("TotalLength", InitialLength.TotalLength);
-  if (InitialLength.isDWARF64())
-    IO.mapRequired("TotalLength64", InitialLength.TotalLength64);
-}
-
 } // end namespace yaml
 
 } // end namespace llvm

llvm/test/ObjectYAML/MachO/DWARF-debug_line.yaml

- Length:              44
       Version:             2
       CuOffset:            0
       AddressSize:         8
       SegmentSelectorSize: 0
       Descriptors:     
         - Address:         0x0000000100000F50
           Length:          52
   debug_pubnames:  
-    Length:          
-      TotalLength:     23
+    Length:          23
     Version:         2
     UnitOffset:      0
     UnitSize:        121
     Entries:         
       - DieOffset:       0x0000002A
         Name:            main
   debug_pubtypes:  
-    Length:          
-      TotalLength:     31
+    Length:          31
     Version:         2
     UnitOffset:      0
     UnitSize:        121
     Entries:         
       - DieOffset:       0x00000060
         Name:            int
       - DieOffset:       0x00000071
         Name:            char

llvm/test/ObjectYAML/MachO/DWARF-pubsections.yaml

debug_str:
     - hello_world.c
     - /Users/cbieneman/dev/open-source/llvm-build-rel
     - main
     - argc
     - argv
     - int
     - char
   debug_pubnames:  
-    Length:
-      TotalLength:       23
+    Length:          23
     Version:         2
     UnitOffset:      0
     UnitSize:        121
     Entries:         
       - DieOffset:       0x0000002A
         Name:            main
   debug_pubtypes:  
-    Length:
-      TotalLength:       31
+    Length:          31
     Version:         2
     UnitOffset:      0
     UnitSize:        121
     Entries:         
       - DieOffset:       0x00000060
         Name:            int
       - DieOffset:       0x00000071
         Name:            char
 ...
 
 #CHECK: DWARF:           
 #CHECK:   debug_pubnames:  
-#CHECK:     Length:
-#CHECK:       TotalLength:       23
+#CHECK:     Length:          0x0000000000000017
 #CHECK:     Version:         2
 #CHECK:     UnitOffset:      0
 #CHECK:     UnitSize:        121
 #CHECK:     Entries:         
 #CHECK:       - DieOffset:       0x0000002A
 #CHECK:         Name:            main
 #CHECK:   debug_pubtypes:  
-#CHECK:     Length:
-#CHECK:       TotalLength:       31
+#CHECK:     Length:          0x000000000000001F
 #CHECK:     Version:         2
 #CHECK:     UnitOffset:      0
 #CHECK:     UnitSize:        121
 #CHECK:     Entries:         
 #CHECK:       - DieOffset:       0x00000060
 #CHECK:         Name:            int
 #CHECK:       - DieOffset:       0x00000071
 #CHECK:         Name:            char

llvm/test/tools/llvm-gsymutil/ARM_AArch64/fat-macho-dwarf.yaml

DWARF:
           Version:             2
           CuOffset:            0
           AddressSize:         4
           SegmentSelectorSize: 0
           Descriptors:
             - Address:         0x000000000000BFF0
               Length:          16
       debug_pubnames:
-        Length:
-          TotalLength:     23
+        Length:          23
         Version:         2
         UnitOffset:      0
         UnitSize:        119
         Entries:
           - DieOffset:       0x00000026
             Name:            main
       debug_pubtypes:
-        Length:
-          TotalLength:     31
+        Length:          31
         Version:         2
         UnitOffset:      0
         UnitSize:        119
         Entries:
           - DieOffset:       0x00000059
             Name:            int
           - DieOffset:       0x0000006F
             Name:            char
DWARF:
           Version:             2
           CuOffset:            0
           AddressSize:         8
           SegmentSelectorSize: 0
           Descriptors:
             - Address:         0x0000000100007F9C
               Length:          28
       debug_pubnames:
-        Length:
-          TotalLength:     23
+        Length:          23
         Version:         2
         UnitOffset:      0
         UnitSize:        126
         Entries:
           - DieOffset:       0x0000002A
             Name:            main
       debug_pubtypes:
-        Length:
-          TotalLength:     31
+        Length:          31
         Version:         2
         UnitOffset:      0
         UnitSize:        126
         Entries:
           - DieOffset:       0x00000060
             Name:            int
           - DieOffset:       0x00000076
             Name:            char

llvm/test/tools/llvm-gsymutil/X86/mach-dwarf.yaml

- Length:              60
       AddressSize:         8
       SegmentSelectorSize: 0
       Descriptors:
         - Address:         0x0000000100000F70
           Length:          17
         - Address:         0x0000000100000F90
           Length:          37
   debug_pubnames:
-    Length:
-      TotalLength:     43
+    Length:          43
     Version:         2
     UnitOffset:      0
     UnitSize:        224
     Entries:
       - DieOffset:       0x0000002A
         Name:            _Z3fooi
       - DieOffset:       0x0000002A
         Name:            foo
       - DieOffset:       0x00000069
         Name:            main
   debug_pubtypes:
-    Length:
-      TotalLength:     31
+    Length:          31
     Version:         2
     UnitOffset:      0
     UnitSize:        224
     Entries:
       - DieOffset:       0x00000062
         Name:            int
       - DieOffset:       0x000000D8
         Name:            char

llvm/test/tools/yaml2obj/ELF/DWARF/debug-gnu-pubnames.yaml

 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    [[ENDIAN]]
   Type:    ET_EXEC
   Machine: EM_X86_64
 DWARF:
   debug_gnu_pubnames:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:
       - DieOffset:  0x12345678
         Descriptor: 0x30
         Name:       abc
       - DieOffset:  0x87654321
FileHeader:
   Type:    ET_EXEC
   Machine: EM_X86_64
 Sections:
   - Name: .debug_gnu_pubnames
     Type: SHT_PROGBITS
     Size: 0x10
 DWARF:
   debug_gnu_pubnames:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []
 
 ## e) Test that yaml2obj emits an error message when both the "Content" and the
 ## "debug_gnu_pubnames" entry are specified at the same time.
 
 # RUN: not yaml2obj --docnum=5 %s 2>&1 | FileCheck %s --check-prefix=ERROR
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_EXEC
   Machine: EM_X86_64
 Sections:
   - Name:    .debug_gnu_pubnames
     Type:    SHT_PROGBITS
     Content: "00"
 DWARF:
   debug_gnu_pubnames:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []
 
 ## f) Test that all the properties can be overridden by the section header when
 ## the "debug_gnu_pubnames" entry doesn't exist.
 
- Name:         .debug_gnu_pubnames
     Info:         1           ## 0 by default.
     AddressAlign: 2           ## 1 by default.
     Address:      0x2020      ## 0x00 by default.
     Offset:       0x50        ## 0x40 for the first section.
   - Name:         .sec        ## Linked by .debug_gnu_pubnames.
     Type:         SHT_STRTAB
 DWARF:
   debug_gnu_pubnames:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []
 
 ## h) Test that yaml2obj emits an error if 'Descriptor' is missing.
 
 # RUN: not yaml2obj --docnum=8 %s -o %t8.o 2>&1 | FileCheck %s --check-prefix=MISSING-KEY --ignore-case
 
-#      MISSING-KEY: YAML:260:9: error: missing required key 'Descriptor'
+#      MISSING-KEY: YAML:{{.*}}:9: error: missing required key 'Descriptor'
 # MISSING-KEY-NEXT:       - DieOffset: 0x12345678
 # MISSING-KEY-NEXT:         ^
 # MISSING-KEY-NEXT: yaml2obj: error: failed to parse YAML input: Invalid argument
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_EXEC
   Machine: EM_X86_64
 DWARF:
   debug_gnu_pubnames:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:
       - DieOffset: 0x12345678
         Name:      abc

llvm/test/tools/yaml2obj/ELF/DWARF/debug-gnu-pubtypes.yaml

 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    [[ENDIAN]]
   Type:    ET_EXEC
   Machine: EM_X86_64
 DWARF:
   debug_gnu_pubtypes:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:
       - DieOffset:  0x12345678
         Descriptor: 0x12
         Name:       abc
       - DieOffset:  0x87654321
FileHeader:
   Type:    ET_EXEC
   Machine: EM_X86_64
 Sections:
   - Name: .debug_gnu_pubtypes
     Type: SHT_PROGBITS
     Size: 0x10
 DWARF:
   debug_gnu_pubtypes:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []
 
 ## e) Test that yaml2obj emits an error message when both the "Content" and the
 ## "debug_gnu_pubtypes" entry are specified at the same time.
 
 # RUN: not yaml2obj --docnum=5 %s 2>&1 | FileCheck %s --check-prefix=ERROR
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_EXEC
   Machine: EM_X86_64
 Sections:
   - Name:    .debug_gnu_pubtypes
     Type:    SHT_PROGBITS
     Content: "00"
 DWARF:
   debug_gnu_pubtypes:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []
 
 ## f) Test that all the properties can be overridden by the section header when
 ## the "debug_gnu_pubtypes" entry doesn't exist.
 
- Name:         .debug_gnu_pubtypes
     Info:         1           ## 0 by default.
     AddressAlign: 2           ## 1 by default.
     Address:      0x2020      ## 0x00 by default.
     Offset:       0x50        ## 0x40 for the first section.
   - Name:         .sec        ## Linked by .debug_gnu_pubtypes.
     Type:         SHT_STRTAB
 DWARF:
   debug_gnu_pubtypes:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []
 
 ## h) Test that yaml2obj emits an error if 'Descriptor' is missing.
 
 # RUN: not yaml2obj --docnum=8 %s -o %t8.o 2>&1 | FileCheck %s --check-prefix=MISSING-KEY --ignore-case
 
-#      MISSING-KEY: YAML:260:9: error: missing required key 'Descriptor'
+#      MISSING-KEY: YAML:{{.*}}:9: error: missing required key 'Descriptor'
 # MISSING-KEY-NEXT:       - DieOffset: 0x12345678
 # MISSING-KEY-NEXT:         ^
 # MISSING-KEY-NEXT: yaml2obj: error: failed to parse YAML input: Invalid argument
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_EXEC
   Machine: EM_X86_64
 DWARF:
   debug_gnu_pubtypes:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:
       - DieOffset: 0x12345678
         Name:      abc

llvm/test/tools/yaml2obj/ELF/DWARF/debug-pubnames.yaml

 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    [[ENDIAN]]
   Type:    ET_EXEC
   Machine: EM_X86_64
 DWARF:
   debug_pubnames:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:
       - DieOffset: 0x12345678
         Name:      abc
       - DieOffset: 0x87654321
         Name:      def
FileHeader:
   Type:    ET_EXEC
   Machine: EM_X86_64
 Sections:
   - Name: .debug_pubnames
     Type: SHT_PROGBITS
     Size: 0x10
 DWARF:
   debug_pubnames:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []
 
 ## e) Test that yaml2obj emits an error message when both the "Content" and the
 ## "debug_pubnames" entry are specified at the same time.
 
 # RUN: not yaml2obj --docnum=5 %s 2>&1 | FileCheck %s --check-prefix=ERROR
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_EXEC
   Machine: EM_X86_64
 Sections:
   - Name:    .debug_pubnames
     Type:    SHT_PROGBITS
     Content: "00"
 DWARF:
   debug_pubnames:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []
 
 ## f) Test that all the properties can be overridden by the section header when
 ## the "debug_pubnames" entry doesn't exist.
 
- Name:         .debug_pubnames
     Info:         1           ## 0 by default.
     AddressAlign: 2           ## 1 by default.
     Address:      0x2020      ## 0x00 by default.
     Offset:       0x50        ## 0x40 for the first section.
   - Name:         .sec        ## Linked by .debug_pubnames.
     Type:         SHT_STRTAB
 DWARF:
   debug_pubnames:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []

llvm/test/tools/yaml2obj/ELF/DWARF/debug-pubtypes.yaml

 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    [[ENDIAN]]
   Type:    ET_EXEC
   Machine: EM_X86_64
 DWARF:
   debug_pubtypes:
-    Length:
-      TotalLength: 0x1234
+    Format:     [[FORMAT=DWARF32]]
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:
       - DieOffset: 0x12345678
         Name:      abc
       - DieOffset: 0x87654321
         Name:      def
FileHeader:
   Type:    ET_EXEC
   Machine: EM_X86_64
 Sections:
   - Name: .debug_pubtypes
     Type: SHT_PROGBITS
     Size: 0x10
 DWARF:
   debug_pubtypes:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []
 
 ## e) Test that yaml2obj emits an error message when both the "Content" and the
 ## "debug_pubtypes" entry are specified at the same time.
 
 # RUN: not yaml2obj --docnum=5 %s 2>&1 | FileCheck %s --check-prefix=ERROR
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_EXEC
   Machine: EM_X86_64
 Sections:
   - Name:    .debug_pubtypes
     Type:    SHT_PROGBITS
     Content: "00"
 DWARF:
   debug_pubtypes:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []
 
 ## f) Test that all the properties can be overridden by the section header when
 ## the "debug_pubtypes" entry doesn't exist.
 
- Name:         .debug_pubtypes
     Info:         1           ## 0 by default.
     AddressAlign: 2           ## 1 by default.
     Address:      0x2020      ## 0x00 by default.
     Offset:       0x50        ## 0x40 for the first section.
   - Name:         .sec        ## Linked by .debug_pubtypes.
     Type:         SHT_STRTAB
 DWARF:
   debug_pubtypes:
-    Length:
-      TotalLength: 0x1234
+    Length:     0x1234
     Version:    2
     UnitOffset: 0x1234
     UnitSize:   0x4321
     Entries:    []

llvm/tools/obj2yaml/dwarf2yaml.cpp

 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFSection.h"
 #include "llvm/ObjectYAML/DWARFYAML.h"
 
 #include <algorithm>
 
 using namespace llvm;
 
-void dumpInitialLength(DataExtractor &Data, uint64_t &Offset,
-                       DWARFYAML::InitialLength &InitialLength) {
-  InitialLength.TotalLength = Data.getU32(&Offset);
-  if (InitialLength.isDWARF64())
-    InitialLength.TotalLength64 = Data.getU64(&Offset);
-}
-
 void dumpDebugAbbrev(DWARFContext &DCtx, DWARFYAML::Data &Y) {
   auto AbbrevSetPtr = DCtx.getDebugAbbrev();
   if (AbbrevSetPtr) {
     for (auto AbbrvDeclSet : *AbbrevSetPtr) {
       for (auto AbbrvDecl : AbbrvDeclSet.second) {
         DWARFYAML::Abbrev Abbrv;
         Abbrv.Code = AbbrvDecl.getCode();
         Abbrv.Tag = AbbrvDecl.getTag();

 
 static DWARFYAML::PubSection dumpPubSection(const DWARFContext &DCtx,
                                             const DWARFSection &Section,
                                             bool IsGNUStyle) {
   DWARFDataExtractor PubSectionData(DCtx.getDWARFObj(), Section,
                                     DCtx.isLittleEndian(), 0);
   DWARFYAML::PubSection Y;
   uint64_t Offset = 0;
-  dumpInitialLength(PubSectionData, Offset, Y.Length);
+  uint64_t Length = PubSectionData.getU32(&Offset);
+  if (Length == dwarf::DW_LENGTH_DWARF64) {
+    Y.Format = dwarf::DWARF64;
+    Y.Length = PubSectionData.getU64(&Offset);
+  } else {
+    Y.Format = dwarf::DWARF32;
+    Y.Length = Length;
+  }
   Y.Version = PubSectionData.getU16(&Offset);
   Y.UnitOffset = PubSectionData.getU32(&Offset);
   Y.UnitSize = PubSectionData.getU32(&Offset);
-  while (Offset < Y.Length.getLength()) {
+  while (Offset < Y.Length) {
     DWARFYAML::PubEntry NewEntry;
     NewEntry.DieOffset = PubSectionData.getU32(&Offset);
     if (IsGNUStyle)
       NewEntry.Descriptor = PubSectionData.getU8(&Offset);
     NewEntry.Name = PubSectionData.getCStr(&Offset);
     Y.Entries.push_back(NewEntry);
   }
 

llvm/unittests/ObjectYAML/DWARFYAMLTest.cpp

)";
   DWARFYAML::AddrTableEntry AddrTableEntry;
   EXPECT_THAT_ERROR(parseDWARFYAML(Yaml, AddrTableEntry),
                     FailedWithMessage("unknown key 'Blah'"));
 }
 
 TEST(DebugPubSection, TestDebugPubSection) {
   StringRef Yaml = R"(
 debug_pubnames:
-  Length:
-    TotalLength: 0x1234
+  Length:        0x1234
   Version:       2
   UnitOffset:    0x4321
   UnitSize:      0x00
   Entries:
     - DieOffset:  0x1234
       Name:       abc
     - DieOffset:  0x4321
       Name:       def
 debug_pubtypes:
-  Length:
-    TotalLength: 0x1234
+  Length:        0x1234
   Version:       2
   UnitOffset:    0x4321
   UnitSize:      0x00
   Entries:
     - DieOffset:  0x1234
       Name:       abc
     - DieOffset:  0x4321
       Name:       def
)";
   EXPECT_EQ(PubTypes.Entries[0].Name, "abc");
   EXPECT_EQ((uint32_t)PubTypes.Entries[1].DieOffset, 0x4321u);
   EXPECT_EQ(PubTypes.Entries[1].Name, "def");
 }
 
 TEST(DebugPubSection, TestUnexpectedDescriptor) {
   StringRef Yaml = R"(
 debug_pubnames:
-  Length:
-    TotalLength: 0x1234
+  Length:        0x1234
   Version:       2
   UnitOffset:    0x4321
   UnitSize:      0x00
   Entries:
     - DieOffset:  0x1234
       Descriptor: 0x12
       Name:       abcd
 )";
   DWARFYAML::Data Data;
   EXPECT_THAT_ERROR(parseDWARFYAML(Yaml, Data),
                     FailedWithMessage("unknown key 'Descriptor'"));
 }
 
 TEST(DebugGNUPubSection, TestDebugGNUPubSections) {
   StringRef Yaml = R"(
 debug_gnu_pubnames:
-  Length:
-    TotalLength: 0x1234
+  Length:        0x1234
   Version:       2
   UnitOffset:    0x4321
   UnitSize:      0x00
   Entries:
     - DieOffset:  0x1234
       Descriptor: 0x12
       Name:       abc
     - DieOffset:  0x4321
       Descriptor: 0x34
       Name:       def
 debug_gnu_pubtypes:
-  Length:
-    TotalLength: 0x1234
+  Length:        0x1234
   Version:       2
   UnitOffset:    0x4321
   UnitSize:      0x00
   Entries:
     - DieOffset:  0x1234
       Descriptor: 0x12
       Name:       abc
     - DieOffset:  0x4321
)";
   EXPECT_EQ((uint32_t)GNUPubTypes.Entries[1].DieOffset, 0x4321u);
   EXPECT_EQ((uint8_t)GNUPubTypes.Entries[1].Descriptor, 0x34);
   EXPECT_EQ(GNUPubTypes.Entries[1].Name, "def");
 }
 
 TEST(DebugGNUPubSection, TestMissingDescriptor) {
   StringRef Yaml = R"(
 debug_gnu_pubnames:
-  Length:
-    TotalLength: 0x1234
+  Length:        0x1234
   Version:       2
   UnitOffset:    0x4321
   UnitSize:      0x00
   Entries:
     - DieOffset: 0x1234
       Name:      abcd
 )";
   DWARFYAML::Data Data;
   EXPECT_THAT_ERROR(parseDWARFYAML(Yaml, Data),
                     FailedWithMessage("missing required key 'Descriptor'"));
 }