[llvm-objcopy] Add LoongArch support

[xen0n]

Summary

Apart from general feature parity, this is also necessary for enabling
ClangBuiltLinux that defaults to using LLVM tools.

While at it, add a missing comment for the Hexagon definition directly
above, so it doesn't get confused with the SPARC definitions.

[jhenderson]

LGTM.

llvm/tools/llvm-objcopy/ObjcopyOptions.cpp

336–339

Whilst you're in the area, would you mind please adding the missing // Hexagon comment? It just helps readability of this table, and means Hexagon doesn't look like it's a variation on SPARC!

[xen0n]

Drive-by fix adding a comment to the Hexagon definition line.

[xen0n]

llvm/tools/llvm-objcopy/ObjcopyOptions.cpp

336–339

No problem; thanks for the suggestion! This is now added.

llvm/test/tools/llvm-objcopy/ELF/binary-output-target.test

 # RUN: llvm-readobj --file-headers %t.sparc.o | FileCheck %s --check-prefixes=CHECK,BE,SPARC,32
 
 # RUN: llvm-objcopy -I binary -O elf32-sparcel %t.txt %t.sparcel.o
 # RUN: llvm-readobj --file-headers %t.sparcel.o | FileCheck %s --check-prefixes=CHECK,LE,SPARCEL,32
 
 # RUN: llvm-objcopy -I binary -O elf32-hexagon %t.txt %t.hexagon.o
 # RUN: llvm-readobj --file-headers %t.hexagon.o | FileCheck %s --check-prefixes=CHECK,LE,HEXAGON,32
 
+# RUN: llvm-objcopy -I binary -O elf32-loongarch %t.txt %t.la32.o
+# RUN: llvm-readobj --file-headers %t.la32.o | FileCheck %s --check-prefixes=CHECK,LE,LA32,32
+
+# RUN: llvm-objcopy -I binary -O elf64-loongarch %t.txt %t.la64.o
+# RUN: llvm-readobj --file-headers %t.la64.o | FileCheck %s --check-prefixes=CHECK,LE,LA64,64
+
 # CHECK: Format:
 # 32-SAME:      elf32-
 # 64-SAME:      elf64-
 # AARCH64-SAME: littleaarch64
 # ARM-SAME:     littlearm
 # HEXAGON-SAME: hexagon
 # I386-SAME:    i386
+# LA32-SAME:    loongarch{{$}}
+# LA64-SAME:    loongarch{{$}}
 # MIPS-SAME:    mips{{$}}
 # RISCV32-SAME: riscv{{$}}
 # RISCV64-SAME: riscv{{$}}
 # PPCBE-SAME:   powerpc{{$}}
 # PPCLE-SAME:   powerpcle{{$}}
 # SPARC-SAME:   sparc
 # SPARCEL-SAME: sparc
 # X86-64-SAME:  x86-64
 
 # AARCH64-NEXT: Arch: aarch64
 # ARM-NEXT:     Arch: arm
 # HEXAGON-NEXT: Arch: hexagon
 # I386-NEXT:    Arch: i386
+# LA32-NEXT:    Arch: loongarch32
+# LA64-NEXT:    Arch: loongarch64
 # MIPS-NEXT:    Arch: mips{{$}}
 # PPC32BE-NEXT: Arch: powerpc{{$}}
 # PPC32LE-NEXT: Arch: powerpcle{{$}}
 # PPC64BE-NEXT: Arch: powerpc64{{$}}
 # PPC64LE-NEXT: Arch: powerpc64le{{$}}
 # RISCV32-NEXT: Arch: riscv32
 # RISCV64-NEXT: Arch: riscv64
 # SPARC-NEXT:   Arch: sparc{{$}}

 
 ## In GNU objcopy, e_machine is EM_NONE unless -B is specifid.
 ## It is not very clear why it behaves this way.
 ## We fill in the field regardless of -B.
 # AARCH64-NEXT:   Machine: EM_AARCH64 (0xB7)
 # ARM-NEXT:       Machine: EM_ARM (0x28)
 # HEXAGON-NEXT:   Machine: EM_HEXAGON (0xA4)
 # I386-NEXT:      Machine: EM_386 (0x3)
+# LA32-NEXT:      Machine: EM_LOONGARCH (0x102)
+# LA64-NEXT:      Machine: EM_LOONGARCH (0x102)
 # MIPS-NEXT:      Machine: EM_MIPS (0x8)
 # PPC32-NEXT:     Machine: EM_PPC (0x14)
 # PPC64-NEXT:     Machine: EM_PPC64 (0x15)
 # RISCV32-NEXT:   Machine: EM_RISCV (0xF3)
 # RISCV64-NEXT:   Machine: EM_RISCV (0xF3)
 # SPARC-NEXT:     Machine: EM_SPARC (0x2)
 # SPARCEL-NEXT:   Machine: EM_SPARC (0x2)
 # X86-64-NEXT:    Machine: EM_X86_64 (0x3E)

llvm/test/tools/llvm-objcopy/ELF/cross-arch-headers.test

 # RUN: llvm-objcopy %t.o -O elf32-sparcel %t.elf32_sparcel.o --split-dwo=%t.elf32_sparcel.dwo
 # RUN: llvm-readobj --file-headers %t.elf32_sparcel.o | FileCheck %s --check-prefixes=CHECK,LE,SPARCEL,32,SYSV
 # RUN: llvm-readobj --file-headers %t.elf32_sparcel.dwo | FileCheck %s --check-prefixes=CHECK,LE,SPARCEL,32,SYSV
 
 # RUN: llvm-objcopy %t.o -O elf32-hexagon %t.elf32_hexagon.o --split-dwo=%t.elf32_hexagon.dwo
 # RUN: llvm-readobj --file-headers %t.elf32_hexagon.o | FileCheck %s --check-prefixes=CHECK,LE,HEXAGON,32,SYSV
 # RUN: llvm-readobj --file-headers %t.elf32_hexagon.dwo | FileCheck %s --check-prefixes=CHECK,LE,HEXAGON,32,SYSV
 
+# RUN: llvm-objcopy %t.o -O elf32-loongarch %t.elf32_loongarch.o --split-dwo=%t.elf32_loongarch.dwo
+# RUN: llvm-readobj --file-headers %t.elf32_loongarch.o | FileCheck %s --check-prefixes=CHECK,LE,LA32,32,SYSV
+# RUN: llvm-readobj --file-headers %t.elf32_loongarch.dwo | FileCheck %s --check-prefixes=CHECK,LE,LA32,32,SYSV
+
+# RUN: llvm-objcopy %t.o -O elf64-loongarch %t.elf64_loongarch.o --split-dwo=%t.elf64_loongarch.dwo
+# RUN: llvm-readobj --file-headers %t.elf64_loongarch.o | FileCheck %s --check-prefixes=CHECK,LE,LA64,64,SYSV
+# RUN: llvm-readobj --file-headers %t.elf64_loongarch.dwo | FileCheck %s --check-prefixes=CHECK,LE,LA64,64,SYSV
+
 !ELF
 FileHeader:
   Class:           ELFCLASS32
   Data:            ELFDATA2LSB
   Type:            ET_EXEC
   # Arbitrary values that do not match any value we convert to via --output-format.
   Machine:         EM_NONE
   OSABI:           ELFOSABI_STANDALONE

 # CHECK: Format:
 # 32-SAME:      elf32-
 # 64-SAME:      elf64-
 # I386-SAME:    i386
 # IAMCU-SAME:   iamcu
 # AARCH-SAME:   aarch64
 # ARM-SAME:     littlearm
 # HEXAGON-SAME: hexagon
+# LA32-SAME:    loongarch{{$}}
+# LA64-SAME:    loongarch{{$}}
 # MIPS-SAME:    mips
 # PPCBE-SAME:   powerpc{{$}}
 # PPCLE-SAME:   powerpcle{{$}}
 # RISCV32-SAME: riscv{{$}}
 # RISCV64-SAME: riscv{{$}}
 # SPARC-SAME:   sparc
 # X86-64-SAME:  x86-64
 # DEFAULT-SAME: unknown
 
 # I386-NEXT:     Arch: i386
 # IAMCU-NEXT:    Arch: i386
 # AARCH-NEXT:    Arch: aarch64
 # ARM-NEXT:      Arch: arm
 # HEXAGON-NEXT:  Arch: hexagon
+# LA32-NEXT:     Arch: loongarch32
+# LA64-NEXT:     Arch: loongarch64
 # MIPSBE-NEXT:   Arch: mips{{$}}
 # MIPSLE-NEXT:   Arch: mipsel{{$}}
 # MIPS64BE-NEXT: Arch: mips64{{$}}
 # MIPS64LE-NEXT: Arch: mips64el{{$}}
 # PPC32BE-NEXT:  Arch: powerpc{{$}}
 # PPC32LE-NEXT:  Arch: powerpcle{{$}}
 # PPC64BE-NEXT:  Arch: powerpc64{{$}}
 # PPC64LE-NEXT:  Arch: powerpc64le{{$}}

 # FREEBSD: OS/ABI: FreeBSD (0x9)
 # DEFAULT: OS/ABI: Standalone (0xFF)
 
 # AARCH:   Machine: EM_AARCH64 (0xB7)
 # ARM:     Machine: EM_ARM (0x28)
 # HEXAGON: Machine: EM_HEXAGON (0xA4)
 # I386:    Machine: EM_386 (0x3)
 # IAMCU:   Machine: EM_IAMCU (0x6)
+# LA32:    Machine: EM_LOONGARCH (0x102)
+# LA64:    Machine: EM_LOONGARCH (0x102)
 # MIPS:    Machine: EM_MIPS (0x8)
 # PPC32:   Machine: EM_PPC (0x14)
 # PPC64:   Machine: EM_PPC64 (0x15)
 # RISCV32: Machine: EM_RISCV (0xF3)
 # RISCV64: Machine: EM_RISCV (0xF3)
 # SPARC:   Machine: EM_SPARC (0x2)
 # X86-64:  Machine: EM_X86_64 (0x3E)
 
 # 32: HeaderSize: 52
 # 64: HeaderSize: 64
 
 # 32: SectionHeaderEntrySize: 40
 # 64: SectionHeaderEntrySize: 64

llvm/tools/llvm-objcopy/ObjcopyOptions.cpp

static const StringMap<MachineInfo> TargetMap{
     {"elf32-ntradlittlemips", {ELF::EM_MIPS, false, true}},
     {"elf32-tradbigmips", {ELF::EM_MIPS, false, false}},
     {"elf32-tradlittlemips", {ELF::EM_MIPS, false, true}},
     {"elf64-tradbigmips", {ELF::EM_MIPS, true, false}},
     {"elf64-tradlittlemips", {ELF::EM_MIPS, true, true}},
     // SPARC
     {"elf32-sparc", {ELF::EM_SPARC, false, false}},
     {"elf32-sparcel", {ELF::EM_SPARC, false, true}},
+    // Hexagon
     {"elf32-hexagon", {ELF::EM_HEXAGON, false, true}},
+    // LoongArch
+    {"elf32-loongarch", {ELF::EM_LOONGARCH, false, true}},
+    {"elf64-loongarch", {ELF::EM_LOONGARCH, true, true}},
 };
 
 static Expected<TargetInfo>
 getOutputTargetInfoByTargetName(StringRef TargetName) {
   StringRef OriginalTargetName = TargetName;
   bool IsFreeBSD = TargetName.consume_back("-freebsd");
   auto Iter = TargetMap.find(TargetName);
   if (Iter == std::end(TargetMap))