[obj2yaml] Support ELF input format in the obj2yaml tool

[atanasyan]

Summary

This patch implements support of ELF input format in the obj2yaml tool.

Please note that now the ELF header e_flags field in the MIPS related test cases handled incorrectly. The obj2yaml prints too many flags. I will fix that in the next patches.

[Bigcheese]

With that change this looks good to me.

test/Object/obj2yaml.test

203

Content needs to be quoted. 0 is the octal prefix in YAML prior to 1.2.

[atanasyan]

test/Object/obj2yaml.test

203

Now the llvm::yaml::Output class prints quotes for strings which are valid numbers. The string 0000023C... is not a valid octal number. Do you suggest to implement a general solution and always print quotes for all string which starts from a digit even if the rest of the string is not a valid number? This greatly simplify the isNumber function from the YAMLTraits.h, but I am still note sure that we need so general modification.

[silvas]

test/Object/obj2yaml.test

203

I wouldn't be opposed to being more conservative when quoting in general. I think that the extra quotes would probably be a net win for the human reader, which has a much harder time knowing if it is an octal number.

That can be a separate patch though. The current patch LGTM.

[silvas]

(actually marking the revision as "accept").

[atanasyan]

In general I do not have any objections on Michael's suggestion. Just do not want to mix all these changes in the single patch.

[atanasyan]

Thanks for review.

Closed by commit rL208752.

test/Object/obj2yaml.test

 RUN: obj2yaml %p/Inputs/trivial-object-test.coff-i386 | FileCheck %s --check-prefix COFF-I386
 RUN: obj2yaml %p/Inputs/trivial-object-test.coff-x86-64 | FileCheck %s --check-prefix COFF-X86-64
-
+RUN: obj2yaml %p/Inputs/trivial-object-test.elf-mipsel | FileCheck %s --check-prefix ELF-MIPSEL
+RUN: obj2yaml %p/Inputs/trivial-object-test.elf-mips64el | FileCheck %s --check-prefix ELF-MIPS64EL
+RUN: obj2yaml %p/Inputs/trivial-object-test.elf-x86-64 | FileCheck %s --check-prefix ELF-X86-64
 
 COFF-I386: header:
 COFF-I386-NEXT:  Machine: IMAGE_FILE_MACHINE_I386
 
 COFF-I386: sections:
 COFF-I386-NEXT:  - Name: .text
 COFF-I386-NEXT:    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
 COFF-I386-NEXT:    Alignment: 16

 COFF-X86-64-NEXT:     StorageClass: IMAGE_SYM_CLASS_EXTERNAL
 
 COFF-X86-64:        - Name: '??__Ex@@YAXXZ'
 COFF-X86-64-NEXT:     Value: 0
 COFF-X86-64-NEXT:     SectionNumber: 3
 COFF-X86-64-NEXT:     SimpleType: IMAGE_SYM_TYPE_NULL
 COFF-X86-64-NEXT:     ComplexType: IMAGE_SYM_DTYPE_FUNCTION
 COFF-X86-64-NEXT:     StorageClass: IMAGE_SYM_CLASS_STATIC
+
+ELF-MIPSEL:      FileHeader:
+ELF-MIPSEL-NEXT:   Class:           ELFCLASS32
+ELF-MIPSEL-NEXT:   Data:            ELFDATA2LSB
+ELF-MIPSEL-NEXT:   Type:            ET_REL
+ELF-MIPSEL-NEXT:   Machine:         EM_MIPS
+ELF-MIPSEL-NEXT:   Flags:           [ EF_MIPS_NOREORDER, EF_MIPS_PIC, EF_MIPS_CPIC, EF_MIPS_ABI_O32, EF_MIPS_ARCH_1, EF_MIPS_ARCH_2, EF_MIPS_ARCH_5, EF_MIPS_ARCH_32 ]
+ELF-MIPSEL-NEXT: Sections:
+ELF-MIPSEL-NEXT:   - Type:            SHT_PROGBITS
+ELF-MIPSEL-NEXT:     Name:            .text
+ELF-MIPSEL-NEXT:     Type:            SHT_PROGBITS
+ELF-MIPSEL-NEXT:     Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+ELF-MIPSEL-NEXT:     Link:            ''
+ELF-MIPSEL-NEXT:     Info:            ''
+ELF-MIPSEL-NEXT:     AddressAlign:    0x0000000000000004
+ELF-MIPSEL-NEXT:     Content:         0000023C00004224E8FFBD271400BFAF1000B0AF218059000000018E000024240000198E09F8200321E000020000198E09F8200321E00002000002241000B08F1400BF8F0800E0031800BD27
+ELF-MIPSEL-NEXT:   - Type:            SHT_REL
+ELF-MIPSEL-NEXT:     Name:            .rel.text
+ELF-MIPSEL-NEXT:     Type:            SHT_REL
+ELF-MIPSEL-NEXT:     Link:            .symtab
+ELF-MIPSEL-NEXT:     Info:            .text
+ELF-MIPSEL-NEXT:     AddressAlign:    0x0000000000000004
+ELF-MIPSEL-NEXT:     Relocations:
+ELF-MIPSEL-NEXT:       - Offset:          0
+ELF-MIPSEL-NEXT:         Symbol:          _gp_disp
+ELF-MIPSEL-NEXT:         Type:            R_MIPS_HI16
+ELF-MIPSEL-NEXT:         Addend:          0
+ELF-MIPSEL-NEXT:       - Offset:          4
+ELF-MIPSEL-NEXT:         Symbol:          _gp_disp
+ELF-MIPSEL-NEXT:         Type:            R_MIPS_LO16
+ELF-MIPSEL-NEXT:         Addend:          0
+ELF-MIPSEL-NEXT:       - Offset:          24
+ELF-MIPSEL-NEXT:         Symbol:          '$.str'
+ELF-MIPSEL-NEXT:         Type:            R_MIPS_GOT16
+ELF-MIPSEL-NEXT:         Addend:          0
+ELF-MIPSEL-NEXT:       - Offset:          28
+ELF-MIPSEL-NEXT:         Symbol:          '$.str'
+ELF-MIPSEL-NEXT:         Type:            R_MIPS_LO16
+ELF-MIPSEL-NEXT:         Addend:          0
+ELF-MIPSEL-NEXT:       - Offset:          32
+ELF-MIPSEL-NEXT:         Symbol:          puts
+ELF-MIPSEL-NEXT:         Type:            R_MIPS_CALL16
+ELF-MIPSEL-NEXT:         Addend:          0
+ELF-MIPSEL-NEXT:       - Offset:          44
+ELF-MIPSEL-NEXT:         Symbol:          SomeOtherFunction
+ELF-MIPSEL-NEXT:         Type:            R_MIPS_CALL16
+ELF-MIPSEL-NEXT:         Addend:          0
+ELF-MIPSEL-NEXT:   - Type:            SHT_PROGBITS
+ELF-MIPSEL-NEXT:     Name:            .data
+ELF-MIPSEL-NEXT:     Type:            SHT_PROGBITS
+ELF-MIPSEL-NEXT:     Flags:           [ SHF_WRITE, SHF_ALLOC ]
+ELF-MIPSEL-NEXT:     Link:            ''
+ELF-MIPSEL-NEXT:     Info:            ''
+ELF-MIPSEL-NEXT:     AddressAlign:    0x0000000000000004
+ELF-MIPSEL-NEXT:     Content:         ''
+ELF-MIPSEL-NEXT:   - Type:            SHT_NOBITS
+ELF-MIPSEL-NEXT:     Name:            .bss
+ELF-MIPSEL-NEXT:     Type:            SHT_NOBITS
+ELF-MIPSEL-NEXT:     Flags:           [ SHF_WRITE, SHF_ALLOC ]
+ELF-MIPSEL-NEXT:     Link:            ''
+ELF-MIPSEL-NEXT:     Info:            ''
+ELF-MIPSEL-NEXT:     AddressAlign:    0x0000000000000004
+ELF-MIPSEL-NEXT:     Content:         ''
+ELF-MIPSEL-NEXT:   - Type:            SHT_PROGBITS
+ELF-MIPSEL-NEXT:     Name:            .rodata.str1.1
+ELF-MIPSEL-NEXT:     Type:            SHT_PROGBITS
+ELF-MIPSEL-NEXT:     Flags:           [ SHF_ALLOC, SHF_MERGE, SHF_STRINGS ]
+ELF-MIPSEL-NEXT:     Link:            ''
+ELF-MIPSEL-NEXT:     Info:            ''
+ELF-MIPSEL-NEXT:     AddressAlign:    0x0000000000000001
+ELF-MIPSEL-NEXT:     Content:         48656C6C6F20576F726C640A00
+ELF-MIPSEL-NEXT:   - Type:            SHT_MIPS_REGINFO
+ELF-MIPSEL-NEXT:     Name:            .reginfo
+ELF-MIPSEL-NEXT:     Type:            SHT_MIPS_REGINFO
+ELF-MIPSEL-NEXT:     Flags:           [ SHF_ALLOC ]
+ELF-MIPSEL-NEXT:     Link:            ''
+ELF-MIPSEL-NEXT:     Info:            ''
+ELF-MIPSEL-NEXT:     AddressAlign:    0x0000000000000001
+ELF-MIPSEL-NEXT:     Content:         '000000000000000000000000000000000000000000000000'
+ELF-MIPSEL-NEXT: Symbols:
+ELF-MIPSEL-NEXT:   Local:
+ELF-MIPSEL-NEXT:     - Name:            trivial.ll
+ELF-MIPSEL-NEXT:       Type:            STT_FILE
+ELF-MIPSEL-NEXT:     - Name:            '$.str'
+ELF-MIPSEL-NEXT:       Type:            STT_OBJECT
+ELF-MIPSEL-NEXT:       Section:         .rodata.str1.1
+ELF-MIPSEL-NEXT:       Size:            0x000000000000000D
+ELF-MIPSEL-NEXT:     - Name:            .text
+ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:       Section:         .text
+ELF-MIPSEL-NEXT:     - Name:            .data
+ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:       Section:         .data
+ELF-MIPSEL-NEXT:     - Name:            .bss
+ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:       Section:         .bss
+ELF-MIPSEL-NEXT:     - Name:            .rodata.str1.1
+ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:       Section:         .rodata.str1.1
+ELF-MIPSEL-NEXT:     - Name:            .reginfo
+ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:       Section:         .reginfo
+ELF-MIPSEL-NEXT:   Global:
+ELF-MIPSEL-NEXT:     - Name:            main
+ELF-MIPSEL-NEXT:       Type:            STT_FUNC
+ELF-MIPSEL-NEXT:       Section:         .text
+ELF-MIPSEL-NEXT:       Size:            0x000000000000004C
+ELF-MIPSEL-NEXT:     - Name:            SomeOtherFunction
+ELF-MIPSEL-NEXT:     - Name:            _gp_disp
+ELF-MIPSEL-NEXT:     - Name:            puts
+
+ELF-MIPS64EL:      FileHeader:
+ELF-MIPS64EL-NEXT:   Class:           ELFCLASS64
+ELF-MIPS64EL-NEXT:   Data:            ELFDATA2LSB
+ELF-MIPS64EL-NEXT:   Type:            ET_REL
+ELF-MIPS64EL-NEXT:   Machine:         EM_MIPS
+ELF-MIPS64EL-NEXT:   Flags:           [ EF_MIPS_ARCH_1, EF_MIPS_ARCH_3 ]
+ELF-MIPS64EL-NEXT: Sections:
+ELF-MIPS64EL-NEXT:   - Type:            SHT_PROGBITS
+ELF-MIPS64EL-NEXT:     Name:            .text
+ELF-MIPS64EL-NEXT:     Type:            SHT_PROGBITS
+ELF-MIPS64EL-NEXT:     Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+ELF-MIPS64EL-NEXT:     Link:            ''
+ELF-MIPS64EL-NEXT:     Info:            ''
+ELF-MIPS64EL-NEXT:     AddressAlign:    0x0000000000000010
+ELF-MIPS64EL-NEXT:     Content:         ''
+ELF-MIPS64EL-NEXT:   - Type:            SHT_PROGBITS
+ELF-MIPS64EL-NEXT:     Name:            .data
+ELF-MIPS64EL-NEXT:     Type:            SHT_PROGBITS
+ELF-MIPS64EL-NEXT:     Flags:           [ SHF_WRITE, SHF_ALLOC ]
+ELF-MIPS64EL-NEXT:     Link:            ''
+ELF-MIPS64EL-NEXT:     Info:            ''
+ELF-MIPS64EL-NEXT:     AddressAlign:    0x0000000000000010
+ELF-MIPS64EL-NEXT:     Content:         '00000000000000000000000000000000'
+ELF-MIPS64EL-NEXT:   - Type:            SHT_RELA
+ELF-MIPS64EL-NEXT:     Name:            .rela.data
+ELF-MIPS64EL-NEXT:     Type:            SHT_RELA
+ELF-MIPS64EL-NEXT:     Link:            .symtab
+ELF-MIPS64EL-NEXT:     Info:            .data
+ELF-MIPS64EL-NEXT:     AddressAlign:    0x0000000000000008
+ELF-MIPS64EL-NEXT:     Relocations:
+ELF-MIPS64EL-NEXT:       - Offset:          0
+ELF-MIPS64EL-NEXT:         Symbol:          zed
+ELF-MIPS64EL-NEXT:         Type:            R_MIPS_64
+ELF-MIPS64EL-NEXT:         Addend:          0
+ELF-MIPS64EL-NEXT:   - Type:            SHT_NOBITS
+ELF-MIPS64EL-NEXT:     Name:            .bss
+ELF-MIPS64EL-NEXT:     Type:            SHT_NOBITS
+ELF-MIPS64EL-NEXT:     Flags:           [ SHF_WRITE, SHF_ALLOC ]
+ELF-MIPS64EL-NEXT:     Link:            ''
+ELF-MIPS64EL-NEXT:     Info:            ''
+ELF-MIPS64EL-NEXT:     AddressAlign:    0x0000000000000010
+ELF-MIPS64EL-NEXT:     Content:         ''
+ELF-MIPS64EL-NEXT:   - Type:            SHT_MIPS_OPTIONS
+ELF-MIPS64EL-NEXT:     Name:            .MIPS.options
+ELF-MIPS64EL-NEXT:     Type:            SHT_MIPS_OPTIONS
+ELF-MIPS64EL-NEXT:     Flags:           [ SHF_ALLOC ]
+ELF-MIPS64EL-NEXT:     Link:            ''
+ELF-MIPS64EL-NEXT:     Info:            ''
+ELF-MIPS64EL-NEXT:     AddressAlign:    0x0000000000000008
+ELF-MIPS64EL-NEXT:     Content:         '01280000000000000000000000000000000000000000000000000000000000000000000000000000'
+ELF-MIPS64EL-NEXT:   - Type:            SHT_PROGBITS
+ELF-MIPS64EL-NEXT:     Name:            .pdr
+ELF-MIPS64EL-NEXT:     Type:            SHT_PROGBITS
+ELF-MIPS64EL-NEXT:     Link:            ''
+ELF-MIPS64EL-NEXT:     Info:            ''
+ELF-MIPS64EL-NEXT:     AddressAlign:    0x0000000000000004
+ELF-MIPS64EL-NEXT:     Content:         ''
+ELF-MIPS64EL-NEXT: Symbols:
+ELF-MIPS64EL-NEXT:   Local:
+ELF-MIPS64EL-NEXT:     - Name:            .text
+ELF-MIPS64EL-NEXT:       Type:            STT_SECTION
+ELF-MIPS64EL-NEXT:       Section:         .text
+ELF-MIPS64EL-NEXT:     - Name:            .data
+ELF-MIPS64EL-NEXT:       Type:            STT_SECTION
+ELF-MIPS64EL-NEXT:       Section:         .data
+ELF-MIPS64EL-NEXT:     - Name:            .bss
+ELF-MIPS64EL-NEXT:       Type:            STT_SECTION
+ELF-MIPS64EL-NEXT:       Section:         .bss
+ELF-MIPS64EL-NEXT:     - Name:            bar
+ELF-MIPS64EL-NEXT:       Section:         .data
+ELF-MIPS64EL-NEXT:     - Name:            .MIPS.options
+ELF-MIPS64EL-NEXT:       Type:            STT_SECTION
+ELF-MIPS64EL-NEXT:       Section:         .MIPS.options
+ELF-MIPS64EL-NEXT:     - Name:            .pdr
+ELF-MIPS64EL-NEXT:       Type:            STT_SECTION
+ELF-MIPS64EL-NEXT:       Section:         .pdr
+ELF-MIPS64EL-NEXT:   Global:
+ELF-MIPS64EL-NEXT:     - Name:            zed
+
+ELF-X86-64:      FileHeader:
+ELF-X86-64-NEXT:   Class:           ELFCLASS64
+ELF-X86-64-NEXT:   Data:            ELFDATA2LSB
+ELF-X86-64-NEXT:   OSABI:           ELFOSABI_GNU
+ELF-X86-64-NEXT:   Type:            ET_REL
+ELF-X86-64-NEXT:   Machine:         EM_X86_64
+ELF-X86-64-NEXT: Sections:
+ELF-X86-64-NEXT:   - Type:            SHT_PROGBITS
+ELF-X86-64-NEXT:     Name:            .text
+ELF-X86-64-NEXT:     Type:            SHT_PROGBITS
+ELF-X86-64-NEXT:     Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+ELF-X86-64-NEXT:     Link:            ''
+ELF-X86-64-NEXT:     Info:            ''
+ELF-X86-64-NEXT:     AddressAlign:    0x0000000000000010
+ELF-X86-64-NEXT:     Content:         4883EC08C744240400000000BF00000000E80000000030C0E8000000008B4424044883C408C3
+ELF-X86-64-NEXT:   - Type:            SHT_PROGBITS
+ELF-X86-64-NEXT:     Name:            .rodata.str1.1
+ELF-X86-64-NEXT:     Type:            SHT_PROGBITS
+ELF-X86-64-NEXT:     Flags:           [ SHF_ALLOC, SHF_MERGE, SHF_STRINGS ]
+ELF-X86-64-NEXT:     Address:         0x0000000000000026
+ELF-X86-64-NEXT:     Link:            ''
+ELF-X86-64-NEXT:     Info:            ''
+ELF-X86-64-NEXT:     AddressAlign:    0x0000000000000001
+ELF-X86-64-NEXT:     Content:         48656C6C6F20576F726C642100
+ELF-X86-64-NEXT:   - Type:            SHT_PROGBITS
+ELF-X86-64-NEXT:     Name:            .note.GNU-stack
+ELF-X86-64-NEXT:     Type:            SHT_PROGBITS
+ELF-X86-64-NEXT:     Address:         0x0000000000000033
+ELF-X86-64-NEXT:     Link:            ''
+ELF-X86-64-NEXT:     Info:            ''
+ELF-X86-64-NEXT:     AddressAlign:    0x0000000000000001
+ELF-X86-64-NEXT:     Content:         ''
+ELF-X86-64-NEXT:   - Type:            SHT_RELA
+ELF-X86-64-NEXT:     Name:            .rela.text
+ELF-X86-64-NEXT:     Type:            SHT_RELA
+ELF-X86-64-NEXT:     Address:         0x0000000000000038
+ELF-X86-64-NEXT:     Link:            .symtab
+ELF-X86-64-NEXT:     Info:            .text
+ELF-X86-64-NEXT:     AddressAlign:    0x0000000000000008
+ELF-X86-64-NEXT:     Relocations:
+ELF-X86-64-NEXT:       - Offset:          13
+ELF-X86-64-NEXT:         Symbol:          .rodata.str1.1
+ELF-X86-64-NEXT:         Type:            R_X86_64_32S
+ELF-X86-64-NEXT:         Addend:          0
+ELF-X86-64-NEXT:       - Offset:          18
+ELF-X86-64-NEXT:         Symbol:          puts
+ELF-X86-64-NEXT:         Type:            R_X86_64_PC32
+ELF-X86-64-NEXT:         Addend:          4294967292
+ELF-X86-64-NEXT:       - Offset:          25
+ELF-X86-64-NEXT:         Symbol:          SomeOtherFunction
+ELF-X86-64-NEXT:         Type:            R_X86_64_PC32
+ELF-X86-64-NEXT:         Addend:          4294967292
+ELF-X86-64-NEXT: Symbols:
+ELF-X86-64-NEXT:   Local:
+ELF-X86-64-NEXT:     - Name:            trivial-object-test.s
+ELF-X86-64-NEXT:       Type:            STT_FILE
+ELF-X86-64-NEXT:     - Name:            .text
+ELF-X86-64-NEXT:       Type:            STT_SECTION
+ELF-X86-64-NEXT:       Section:         .text
+ELF-X86-64-NEXT:     - Name:            .rodata.str1.1
+ELF-X86-64-NEXT:       Type:            STT_SECTION
+ELF-X86-64-NEXT:       Section:         .rodata.str1.1
+ELF-X86-64-NEXT:     - Name:            .note.GNU-stack
+ELF-X86-64-NEXT:       Type:            STT_SECTION
+ELF-X86-64-NEXT:       Section:         .note.GNU-stack
+ELF-X86-64-NEXT:   Global:
+ELF-X86-64-NEXT:     - Name:            main
+ELF-X86-64-NEXT:       Type:            STT_FUNC
+ELF-X86-64-NEXT:       Section:         .text
+ELF-X86-64-NEXT:       Size:            0x0000000000000026
+ELF-X86-64-NEXT:     - Name:            SomeOtherFunction
+ELF-X86-64-NEXT:     - Name:            puts

tools/obj2yaml/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   Object
   Support
   )
 
 add_llvm_utility(obj2yaml
-  obj2yaml.cpp coff2yaml.cpp Error.cpp
+  obj2yaml.cpp coff2yaml.cpp elf2yaml.cpp Error.cpp
   )

tools/obj2yaml/elf2yaml.cpp

+//===------ utils/elf2yaml.cpp - obj2yaml conversion tool -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Error.h"
+#include "obj2yaml.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Object/ELFObjectFile.h"
+#include "llvm/Object/ELFYAML.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/YAMLTraits.h"
+
+using namespace llvm;
+
+namespace {
+
+template <class ELFT>
+class ELFDumper {
+  typedef typename object::ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
+  typedef typename object::ELFFile<ELFT>::Elf_Sym_Iter Elf_Sym_Iter;
+
+  const object::ELFFile<ELFT> &Obj;
+
+  error_code dumpSymbol(Elf_Sym_Iter Sym, ELFYAML::Symbol &S);
+  error_code dumpCommonSection(const Elf_Shdr *Shdr, ELFYAML::Section &S);
+  template <class RelT>
+  error_code dumpRelocation(const Elf_Shdr *Shdr, const RelT *Rel,
+                            ELFYAML::Relocation &R);
+
+  ErrorOr<ELFYAML::RelocationSection *> dumpRelSection(const Elf_Shdr *Shdr);
+  ErrorOr<ELFYAML::RelocationSection *> dumpRelaSection(const Elf_Shdr *Shdr);
+  ErrorOr<ELFYAML::RawContentSection *>
+  dumpContentSection(const Elf_Shdr *Shdr);
+
+public:
+  ELFDumper(const object::ELFFile<ELFT> &O);
+  ErrorOr<ELFYAML::Object *> dump();
+};
+
+}
+
+template <class ELFT>
+ELFDumper<ELFT>::ELFDumper(const object::ELFFile<ELFT> &O)
+    : Obj(O) {}
+
+template <class ELFT>
+ErrorOr<ELFYAML::Object *> ELFDumper<ELFT>::dump() {
+  auto Y = make_unique<ELFYAML::Object>();
+
+  // Dump header
+  Y->Header.Class = ELFYAML::ELF_ELFCLASS(Obj.getHeader()->getFileClass());
+  Y->Header.Data = ELFYAML::ELF_ELFDATA(Obj.getHeader()->getDataEncoding());
+  Y->Header.OSABI = Obj.getHeader()->e_ident[ELF::EI_OSABI];
+  Y->Header.Type = Obj.getHeader()->e_type;
+  Y->Header.Machine = Obj.getHeader()->e_machine;
+  Y->Header.Flags = Obj.getHeader()->e_flags;
+  Y->Header.Entry = Obj.getHeader()->e_entry;
+
+  // Dump sections
+  for (const Elf_Shdr &Sec : Obj.sections()) {
+    switch (Sec.sh_type) {
+    case ELF::SHT_NULL:
+    case ELF::SHT_SYMTAB:
+    case ELF::SHT_DYNSYM:
+    case ELF::SHT_STRTAB:
+      // Do not dump these sections.
+      break;
+    case ELF::SHT_RELA: {
+      ErrorOr<ELFYAML::RelocationSection *> S = dumpRelaSection(&Sec);
+      if (error_code EC = S.getError())
+        return EC;
+      Y->Sections.push_back(std::unique_ptr<ELFYAML::Section>(S.get()));
+      break;
+    }
+    case ELF::SHT_REL: {
+      ErrorOr<ELFYAML::RelocationSection *> S = dumpRelSection(&Sec);
+      if (error_code EC = S.getError())
+        return EC;
+      Y->Sections.push_back(std::unique_ptr<ELFYAML::Section>(S.get()));
+      break;
+    }
+    default: {
+      ErrorOr<ELFYAML::RawContentSection *> S = dumpContentSection(&Sec);
+      if (error_code EC = S.getError())
+        return EC;
+      Y->Sections.push_back(std::unique_ptr<ELFYAML::Section>(S.get()));
+    }
+    }
+  }
+
+  // Dump symbols
+  bool IsFirstSym = true;
+  for (auto SI = Obj.begin_symbols(), SE = Obj.end_symbols(); SI != SE; ++SI) {
+    if (IsFirstSym) {
+      IsFirstSym = false;
+      continue;
+    }
+
+    ELFYAML::Symbol S;
+    if (error_code EC = ELFDumper<ELFT>::dumpSymbol(SI, S))
+      return EC;
+
+    switch (SI->getBinding())
+    {
+    case ELF::STB_LOCAL:
+      Y->Symbols.Local.push_back(S);
+      break;
+    case ELF::STB_GLOBAL:
+      Y->Symbols.Global.push_back(S);
+      break;
+    case ELF::STB_WEAK:
+      Y->Symbols.Weak.push_back(S);
+      break;
+    default:
+      llvm_unreachable("Unknown ELF symbol binding");
+    }
+  }
+
+  return Y.release();
+}
+
+template <class ELFT>
+error_code ELFDumper<ELFT>::dumpSymbol(Elf_Sym_Iter Sym, ELFYAML::Symbol &S) {
+  S.Type = Sym->getType();
+  S.Value = Sym->st_value;
+  S.Size = Sym->st_size;
+
+  ErrorOr<StringRef> NameOrErr = Obj.getSymbolName(Sym);
+  if (error_code EC = NameOrErr.getError())
+    return EC;
+  S.Name = NameOrErr.get();
+
+  const Elf_Shdr *Shdr = Obj.getSection(&*Sym);
+  if (!Shdr)
+    return obj2yaml_error::success;
+
+  NameOrErr = Obj.getSectionName(Shdr);
+  if (error_code EC = NameOrErr.getError())
+    return EC;
+  S.Section = NameOrErr.get();
+
+  return obj2yaml_error::success;
+}
+
+template <class ELFT>
+template <class RelT>
+error_code ELFDumper<ELFT>::dumpRelocation(const Elf_Shdr *Shdr,
+                                           const RelT *Rel,
+                                           ELFYAML::Relocation &R) {
+  R.Type = Rel->getType(Obj.isMips64EL());
+  R.Offset = Rel->r_offset;
+  R.Addend = 0;
+
+  auto NamePair = Obj.getRelocationSymbol(Shdr, Rel);
+  if (!NamePair.first)
+    return obj2yaml_error::success;
+
+  ErrorOr<StringRef> NameOrErr =
+      Obj.getSymbolName(NamePair.first, NamePair.second);
+  if (error_code EC = NameOrErr.getError())
+    return EC;
+  R.Symbol = NameOrErr.get();
+
+  return obj2yaml_error::success;
+}
+
+template <class ELFT>
+error_code ELFDumper<ELFT>::dumpCommonSection(const Elf_Shdr *Shdr,
+                                              ELFYAML::Section &S) {
+  S.Type = Shdr->sh_type;
+  S.Flags = Shdr->sh_flags;
+  S.Address = Shdr->sh_addr;
+  S.AddressAlign = Shdr->sh_addralign;
+
+  ErrorOr<StringRef> NameOrErr = Obj.getSectionName(Shdr);
+  if (error_code EC = NameOrErr.getError())
+    return EC;
+  S.Name = NameOrErr.get();
+
+  if (Shdr->sh_link != ELF::SHN_UNDEF) {
+    if (const Elf_Shdr *LinkSection = Obj.getSection(Shdr->sh_link)) {
+      NameOrErr = Obj.getSectionName(LinkSection);
+      if (error_code EC = NameOrErr.getError())
+        return EC;
+      S.Link = NameOrErr.get();
+    }
+  }
+  if (Shdr->sh_info != ELF::SHN_UNDEF) {
+    if (const Elf_Shdr *InfoSection = Obj.getSection(Shdr->sh_info)) {
+      NameOrErr = Obj.getSectionName(InfoSection);
+      if (error_code EC = NameOrErr.getError())
+        return EC;
+      S.Info = NameOrErr.get();
+    }
+  }
+  return obj2yaml_error::success;
+}
+
+template <class ELFT>
+ErrorOr<ELFYAML::RelocationSection *>
+ELFDumper<ELFT>::dumpRelSection(const Elf_Shdr *Shdr) {
+  assert(Shdr->sh_type == ELF::SHT_REL && "Section type is not SHT_REL");
+  auto S = make_unique<ELFYAML::RelocationSection>();
+
+  if (error_code EC = dumpCommonSection(Shdr, *S))
+    return EC;
+
+  for (auto RI = Obj.begin_rel(Shdr), RE = Obj.end_rel(Shdr); RI != RE;
+       ++RI) {
+    ELFYAML::Relocation R;
+    if (error_code EC = dumpRelocation(Shdr, &*RI, R))
+      return EC;
+    S->Relocations.push_back(R);
+  }
+
+  return S.release();
+}
+
+template <class ELFT>
+ErrorOr<ELFYAML::RelocationSection *>
+ELFDumper<ELFT>::dumpRelaSection(const Elf_Shdr *Shdr) {
+  assert(Shdr->sh_type == ELF::SHT_RELA && "Section type is not SHT_RELA");
+  auto S = make_unique<ELFYAML::RelocationSection>();
+
+  if (error_code EC = dumpCommonSection(Shdr, *S))
+    return EC;
+
+  for (auto RI = Obj.begin_rela(Shdr), RE = Obj.end_rela(Shdr); RI != RE;
+       ++RI) {
+    ELFYAML::Relocation R;
+    if (error_code EC = dumpRelocation(Shdr, &*RI, R))
+      return EC;
+    R.Addend = RI->r_addend;
+    S->Relocations.push_back(R);
+  }
+
+  return S.release();
+}
+
+template <class ELFT>
+ErrorOr<ELFYAML::RawContentSection *>
+ELFDumper<ELFT>::dumpContentSection(const Elf_Shdr *Shdr) {
+  auto S = make_unique<ELFYAML::RawContentSection>();
+
+  if (error_code EC = dumpCommonSection(Shdr, *S))
+    return EC;
+
+  ErrorOr<ArrayRef<uint8_t>> ContentOrErr = Obj.getSectionContents(Shdr);
+  if (error_code EC = ContentOrErr.getError())
+    return EC;
+  S->Content = object::yaml::BinaryRef(ContentOrErr.get());
+
+  return S.release();
+}
+
+template <class ELFT>
+static error_code elf2yaml(raw_ostream &Out, const object::ELFFile<ELFT> &Obj) {
+  ELFDumper<ELFT> Dumper(Obj);
+  ErrorOr<ELFYAML::Object *> YAMLOrErr = Dumper.dump();
+  if (error_code EC = YAMLOrErr.getError())
+    return EC;
+
+  std::unique_ptr<ELFYAML::Object> YAML(YAMLOrErr.get());
+  yaml::Output Yout(Out);
+  Yout << *YAML;
+
+  return object::object_error::success;
+}
+
+error_code elf2yaml(raw_ostream &Out, const object::ObjectFile &Obj) {
+  if (const auto *ELFObj = dyn_cast<object::ELF32LEObjectFile>(&Obj))
+    return elf2yaml(Out, *ELFObj->getELFFile());
+
+  if (const auto *ELFObj = dyn_cast<object::ELF32BEObjectFile>(&Obj))
+    return elf2yaml(Out, *ELFObj->getELFFile());
+
+  if (const auto *ELFObj = dyn_cast<object::ELF64LEObjectFile>(&Obj))
+    return elf2yaml(Out, *ELFObj->getELFFile());
+
+  if (const auto *ELFObj = dyn_cast<object::ELF64BEObjectFile>(&Obj))
+    return elf2yaml(Out, *ELFObj->getELFFile());
+
+  return obj2yaml_error::unsupported_obj_file_format;
+}

tools/obj2yaml/obj2yaml.h

 #define LLVM_TOOLS_OBJ2YAML_H
 
 #include "llvm/Object/COFF.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/system_error.h"
 
 llvm::error_code coff2yaml(llvm::raw_ostream &Out,
                            const llvm::object::COFFObjectFile &Obj);
+llvm::error_code elf2yaml(llvm::raw_ostream &Out,
+                          const llvm::object::ObjectFile &Obj);
 
 #endif

tools/obj2yaml/obj2yaml.cpp

 #include "llvm/Support/Signals.h"
 
 using namespace llvm;
 using namespace llvm::object;
 
 static error_code dumpObject(const ObjectFile &Obj) {
   if (Obj.isCOFF())
     return coff2yaml(outs(), cast<COFFObjectFile>(Obj));
+  if (Obj.isELF())
+    return elf2yaml(outs(), Obj);
 
   return obj2yaml_error::unsupported_obj_file_format;
 }
 
 static error_code dumpInput(StringRef File) {
   if (File != "-" && !sys::fs::exists(File))
     return obj2yaml_error::file_not_found;