[JITLink][ELF/AARCH64] Implement R_AARCH64_ABS64 relocation type

[sunho]

Summary

Implement R_AARCH64_ABS64 relocation entry. This relocation type is generated when creating a static function potiner to symbol.

[sunho]

Rebase

[sunho]

Rebase

[sgraenitz]

LGTM, thanks for working on this!

[sunho]

Rebase

[lhames]

LGTM. Thanks @sunho!

llvm/lib/ExecutionEngine/JITLink/ELF_aarch64.cpp

enum ELFAArch64RelocationKind : Edge::Kind {
     ELFCall26 = Edge::FirstRelocation,
     ELFAdrPage21,
     ELFAddAbs12,
     ELFLdSt8Abs12,
     ELFLdSt16Abs12,
     ELFLdSt32Abs12,
     ELFLdSt64Abs12,
     ELFLdSt128Abs12,
+    ELFAbs64,
   };
 
   static Expected<ELFAArch64RelocationKind>
   getRelocationKind(const uint32_t Type) {
     using namespace aarch64;
     switch (Type) {
     case ELF::R_AARCH64_CALL26:
       return ELFCall26;
     case ELF::R_AARCH64_ADR_PREL_PG_HI21:
       return ELFAdrPage21;
     case ELF::R_AARCH64_ADD_ABS_LO12_NC:
       return ELFAddAbs12;
     case ELF::R_AARCH64_LDST8_ABS_LO12_NC:
       return ELFLdSt8Abs12;
     case ELF::R_AARCH64_LDST16_ABS_LO12_NC:
       return ELFLdSt16Abs12;
     case ELF::R_AARCH64_LDST32_ABS_LO12_NC:
       return ELFLdSt32Abs12;
     case ELF::R_AARCH64_LDST64_ABS_LO12_NC:
       return ELFLdSt64Abs12;
     case ELF::R_AARCH64_LDST128_ABS_LO12_NC:
       return ELFLdSt128Abs12;
+    case ELF::R_AARCH64_ABS64:
+      return ELFAbs64;
     }
 
     return make_error<JITLinkError>("Unsupported aarch64 relocation:" +
                                     formatv("{0:d}", Type));
   }
 
   Error addRelocations() override {
     LLVM_DEBUG(dbgs() << "Processing relocations:\n");
case ELFLdSt128Abs12: {
           aarch64::getPageOffset12Shift(Instr) != 4)
         return make_error<JITLinkError>(
             "R_AARCH64_LDST128_ABS_LO12_NC target is not a "
             "LDR/STR (imm12, 128 bit) instruction");
 
       Kind = aarch64::PageOffset12;
       break;
     }
+    case ELFAbs64: {
+      Kind = aarch64::Pointer64;
+      break;
+    }
     };
 
     Edge GE(Kind, Offset, *GraphSymbol, Addend);
     LLVM_DEBUG({
       dbgs() << "    ";
       printEdge(dbgs(), BlockToFix, GE, aarch64::getEdgeKindName(Kind));
       dbgs() << "\n";
     });
const char *getELFAArch64RelocationKindName(Edge::Kind R) {
     case ELFLdSt16Abs12:
       return "ELFLdSt16Abs12";
     case ELFLdSt32Abs12:
       return "ELFLdSt32Abs12";
     case ELFLdSt64Abs12:
       return "ELFLdSt64Abs12";
     case ELFLdSt128Abs12:
       return "ELFLdSt128Abs12";
+    case ELFAbs64:
+      return "ELFAbs64";
     default:
       return getGenericEdgeKindName(static_cast<Edge::Kind>(R));
     }
   }
 
 public:
   ELFLinkGraphBuilder_aarch64(StringRef FileName,
                               const object::ELFFile<ELFT> &Obj, const Triple T)

llvm/test/ExecutionEngine/JITLink/AArch64/ELF_aarch64_relocations.s

 # RUN: rm -rf %t && mkdir -p %t
 # RUN: llvm-mc -triple=aarch64-unknown-linux-gnu -relax-relocations=false -position-independent -filetype=obj -o %t/elf_reloc.o %s
-# RUN: llvm-jitlink -noexec -check %s %t/elf_reloc.o
+# RUN: llvm-jitlink -noexec \
+# RUN:              -check %s %t/elf_reloc.o
 
         .text
 
         .globl  main
         .p2align  2
         .type main,@function
 main:
         ret
test_str_32bit:
         str  w0, [x1, :lo12:named_data]
         .size test_str_32bit, .-test_str_32bit
 
         .globl  test_str_64bit
 test_str_64bit:
         str  x0, [x1, :lo12:named_data]
         .size test_str_64bit, .-test_str_64bit
 
+# Check R_AARCH64_ABS64 relocation of a function pointer to local symbol
+#
+# jitlink-check: *{8}local_func_addr_quad = named_func
+        .globl  local_func_addr_quad
+        .p2align  3
+local_func_addr_quad:
+        .xword  named_func
+        .size local_func_addr_quad, 8
+
         .globl  named_data
         .p2align  4
         .type   named_data,@object
 named_data:
         .quad   0x2222222222222222
         .quad   0x3333333333333333
         .size   named_data, .-named_data
+
+        .globl  named_func
+        .p2align  2
+        .type named_func,@function
+named_func:
+        ret
+        .size   named_func, .-named_func