[ARC] Prepare the implementation of relocation for lld

[xiangzhai]

Summary

Hi LLVM developers,

Prepare the implementation of ARC target ELF relocation for lld, so at present it needs ARC GNU toolchain to generate ELF object:

$ cat arc-hello.s
main:
  bl memset
  bl strncpy
  bl puts

$ /opt/arc-gnu/bin/arc-elf32-gcc -mcpu=arc600 -o arc-hello.o -c arc-hello.s

Relocation:

$ /opt/arc-gnu/bin/arc-elf32-readelf -r arc-hello.o

Relocation section '.rela.text' at offset 0x108 contains 3 entries:
 Offset     Info    Type            Sym.Value  Sym. Name + Addend
00000000  00000611 R_ARC_S25W_PCREL  00000000   memset + 0
00000004  00000711 R_ARC_S25W_PCREL  00000000   strncpy + 0
00000008  00000811 R_ARC_S25W_PCREL  00000000   puts + 0

LLD:

$ /opt/llvm-svn/bin/ld.lld -o arc-hello-lld arc-hello.o -L/opt/arc-gnu/lib/gcc/arc-elf32/7.1.1/arc600 -L/opt/arc-gnu/lib/gcc/arc-elf32/7.1.1/../../../../arc-elf32/lib/arc600 -L/opt/arc-gnu/lib/gcc/arc-elf32/7.1.1 -L/opt/arc-gnu/lib/gcc/arc-elf32/7.1.1/../../../../arc-elf32/lib --start-group -lgcc -lc -lnosys --end-group -Ttext=0

Please review it, thanks a lot!

Regards,
Leslie Zhai

[kparzysz]

Should you also change lib/ObjectYAML/ELFYAML.cpp?

[kparzysz]

If you decide that the YAML file doesn't need to be modified in this patch, the rest LGTM.

[xiangzhai]

Hi Krzysztof,

Thanks for your review!

I updated my patch as your suggestion, but at present there is *no* ARC Specific e_flags defined.

Regards,
Leslie Zhai

[kparzysz]

include/llvm/BinaryFormat/ELF.h

440

If this doesn't add any flags, it shouldn't be here. Otherwise LGTM.

[xiangzhai]

Add ARC Specific e_flags.

include/llvm/BinaryFormat/ELF.h

enum : unsigned {
   EF_ARM_EABI_VER1 = 0x01000000U,
   EF_ARM_EABI_VER2 = 0x02000000U,
   EF_ARM_EABI_VER3 = 0x03000000U,
   EF_ARM_EABI_VER4 = 0x04000000U,
   EF_ARM_EABI_VER5 = 0x05000000U,
   EF_ARM_EABIMASK = 0xFF000000U
 };
 
+// ELF Relocation types for ARC
+enum {
+#include "ELFRelocs/ARC.def"
+};
+
 // ELF Relocation types for ARM
 enum {
 #include "ELFRelocs/ARM.def"
 };
 
 // AVR specific e_flags
 enum : unsigned {
   EF_AVR_ARCH_AVR1 = 1,
   EF_AVR_ARCH_AVR2 = 2,
   EF_AVR_ARCH_AVR25 = 25,
   EF_AVR_ARCH_AVR3 = 3,
   EF_AVR_ARCH_AVR31 = 31,
   EF_AVR_ARCH_AVR35 = 35,
   EF_AVR_ARCH_AVR4 = 4,
   EF_AVR_ARCH_AVR5 = 5,
   EF_AVR_ARCH_AVR51 = 51,

include/llvm/BinaryFormat/ELFRelocs/ARC.def

+
+#ifndef ELF_RELOC
+#error "ELF_RELOC must be defined"
+#endif
+
+ELF_RELOC(R_ARC_NONE,                  0)
+ELF_RELOC(R_ARC_8,                     1)
+ELF_RELOC(R_ARC_16,                    2)
+ELF_RELOC(R_ARC_24,                    3)
+ELF_RELOC(R_ARC_32,                    4)
+ELF_RELOC(R_ARC_N8,                    8)
+ELF_RELOC(R_ARC_N16,                   9)
+ELF_RELOC(R_ARC_N24,                  10)
+ELF_RELOC(R_ARC_N32,                  11)
+ELF_RELOC(R_ARC_SDA,                  12)
+ELF_RELOC(R_ARC_SECTOFF,              13)
+ELF_RELOC(R_ARC_S21H_PCREL,           14)
+ELF_RELOC(R_ARC_S21W_PCREL,           15)
+ELF_RELOC(R_ARC_S25H_PCREL,           16)
+ELF_RELOC(R_ARC_S25W_PCREL,           17)
+ELF_RELOC(R_ARC_SDA32,                18)
+ELF_RELOC(R_ARC_SDA_LDST,             19)
+ELF_RELOC(R_ARC_SDA_LDST1,            20)
+ELF_RELOC(R_ARC_SDA_LDST2,            21)
+ELF_RELOC(R_ARC_SDA16_LD,             22)
+ELF_RELOC(R_ARC_SDA16_LD1,            23)
+ELF_RELOC(R_ARC_SDA16_LD2,            24)
+ELF_RELOC(R_ARC_S13_PCREL,            25)
+ELF_RELOC(R_ARC_W,                    26)
+ELF_RELOC(R_ARC_32_ME,                27)
+ELF_RELOC(R_ARC_32_ME_S,             105)
+ELF_RELOC(R_ARC_N32_ME,               28)
+ELF_RELOC(R_ARC_SECTOFF_ME,           29)
+ELF_RELOC(R_ARC_SDA32_ME,             30)
+ELF_RELOC(R_ARC_W_ME,                 31)
+ELF_RELOC(R_AC_SECTOFF_U8,            35)
+ELF_RELOC(R_AC_SECTOFF_U8_1,          36)
+ELF_RELOC(R_AC_SECTOFF_U8_2,          37)
+ELF_RELOC(R_AC_SECTOFF_S9,            38)
+ELF_RELOC(R_AC_SECTOFF_S9_1,          39)
+ELF_RELOC(R_AC_SECTOFF_S9_2,          40)
+ELF_RELOC(R_ARC_SECTOFF_ME_1,         41)
+ELF_RELOC(R_ARC_SECTOFF_ME_2,         42)
+ELF_RELOC(R_ARC_SECTOFF_1,            43)
+ELF_RELOC(R_ARC_SECTOFF_2,            44)
+ELF_RELOC(R_ARC_SDA_12,               45)
+ELF_RELOC(R_ARC_SDA16_ST2,            48)
+ELF_RELOC(R_ARC_32_PCREL,             49)
+ELF_RELOC(R_ARC_PC32,                 50)
+ELF_RELOC(R_ARC_GOT32,                59)
+ELF_RELOC(R_ARC_GOTPC32,              51)
+ELF_RELOC(R_ARC_PLT32,                52)
+ELF_RELOC(R_ARC_COPY,                 53)
+ELF_RELOC(R_ARC_GLOB_DAT,             54)
+ELF_RELOC(R_ARC_JMP_SLOT,             55)
+ELF_RELOC(R_ARC_RELATIVE,             56)
+ELF_RELOC(R_ARC_GOTOFF,               57)
+ELF_RELOC(R_ARC_GOTPC,                58)
+ELF_RELOC(R_ARC_S21W_PCREL_PLT,       60)
+ELF_RELOC(R_ARC_S25H_PCREL_PLT,       61)
+ELF_RELOC(R_ARC_JLI_SECTOFF,          63)
+ELF_RELOC(R_ARC_TLS_DTPMOD,           66)
+ELF_RELOC(R_ARC_TLS_TPOFF,            68)
+ELF_RELOC(R_ARC_TLS_GD_GOT,           69)
+ELF_RELOC(R_ARC_TLS_GD_LD,            70)
+ELF_RELOC(R_ARC_TLS_GD_CALL,          71)
+ELF_RELOC(R_ARC_TLS_IE_GOT,           72)
+ELF_RELOC(R_ARC_TLS_DTPOFF,           67)
+ELF_RELOC(R_ARC_TLS_DTPOFF_S9,        73)
+ELF_RELOC(R_ARC_TLS_LE_S9,            74)
+ELF_RELOC(R_ARC_TLS_LE_32,            75)
+ELF_RELOC(R_ARC_S25W_PCREL_PLT,       76)
+ELF_RELOC(R_ARC_S21H_PCREL_PLT,       77)
+ELF_RELOC(R_ARC_NPS_CMEM16,           78)

include/llvm/module.modulemap

 
 module LLVM_BinaryFormat {
     requires cplusplus
     umbrella "BinaryFormat" module * { export * }
     textual header "BinaryFormat/Dwarf.def"
     textual header "BinaryFormat/MachO.def"
     textual header "BinaryFormat/ELFRelocs/AArch64.def"
     textual header "BinaryFormat/ELFRelocs/AMDGPU.def"
+    textual header "BinaryFormat/ELFRelocs/ARC.def"
     textual header "BinaryFormat/ELFRelocs/ARM.def"
     textual header "BinaryFormat/ELFRelocs/AVR.def"
     textual header "BinaryFormat/ELFRelocs/BPF.def"
     textual header "BinaryFormat/ELFRelocs/Hexagon.def"
     textual header "BinaryFormat/ELFRelocs/i386.def"
     textual header "BinaryFormat/ELFRelocs/Lanai.def"
     textual header "BinaryFormat/ELFRelocs/Mips.def"
     textual header "BinaryFormat/ELFRelocs/PowerPC64.def"

lib/Object/ELF.cpp

#include "llvm/BinaryFormat/ELFRelocs/Mips.def"
     break;
   case ELF::EM_AARCH64:
     switch (Type) {
 #include "llvm/BinaryFormat/ELFRelocs/AArch64.def"
     default:
       break;
     }
     break;
+  case ELF::EM_ARC_COMPACT:
+  case ELF::EM_ARC_COMPACT2:
+    switch (Type) {
+#include "llvm/BinaryFormat/ELFRelocs/ARC.def"
+    default:
+      break;
+    }
+    break;
   case ELF::EM_ARM:
     switch (Type) {
 #include "llvm/BinaryFormat/ELFRelocs/ARM.def"
     default:
       break;
     }
     break;
   case ELF::EM_AVR: