[ELF] - Explicitly list supported relocations for x64 target.

[grimar]

Summary

The same we did for x86 earlier.

[ruiu]

LGTM

lld/trunk/ELF/Target.cpp

template <class ELFT> X86_64TargetInfo<ELFT>::X86_64TargetInfo() {
   // FreeBSD automatically promotes large, superpage-aligned allocations.
   DefaultImageBase = 0x200000;
 }
 
 template <class ELFT>
 RelExpr X86_64TargetInfo<ELFT>::getRelExpr(uint32_t Type,
                                            const SymbolBody &S) const {
   switch (Type) {
-  default:
+  case R_X86_64_32:
+  case R_X86_64_32S:
+  case R_X86_64_64:
+  case R_X86_64_DTPOFF32:
+  case R_X86_64_DTPOFF64:
     return R_ABS;
   case R_X86_64_TPOFF32:
     return R_TLS;
   case R_X86_64_TLSLD:
     return R_TLSLD_PC;
   case R_X86_64_TLSGD:
     return R_TLSGD_PC;
   case R_X86_64_SIZE32:
case R_X86_64_GOT64:
     return R_GOT_FROM_END;
   case R_X86_64_GOTPCREL:
   case R_X86_64_GOTPCRELX:
   case R_X86_64_REX_GOTPCRELX:
   case R_X86_64_GOTTPOFF:
     return R_GOT_PC;
   case R_X86_64_NONE:
     return R_HINT;
+  default:
+    error("do not know how to handle relocation '" + toString(Type) + "' (" +
+          Twine(Type) + ")");
+    return R_HINT;
   }
 }
 
 template <class ELFT>
 void X86_64TargetInfo<ELFT>::writeGotPltHeader(uint8_t *Buf) const {
   // The first entry holds the value of _DYNAMIC. It is not clear why that is
   // required, but it is documented in the psabi and the glibc dynamic linker
   // seems to use it (note that this is relevant for linking ld.so, not any
void X86_64TargetInfo<ELFT>::relocateOne(uint8_t *Loc, uint32_t Type,
   case R_X86_64_DTPOFF64:
   case R_X86_64_GLOB_DAT:
   case R_X86_64_PC64:
   case R_X86_64_SIZE64:
   case R_X86_64_GOT64:
     write64le(Loc, Val);
     break;
   default:
-    error(getErrorLocation(Loc) + "unrecognized reloc " + Twine(Type));
+    llvm_unreachable("unexpected relocation");
   }
 }
 
 template <class ELFT>
 RelExpr X86_64TargetInfo<ELFT>::adjustRelaxExpr(uint32_t Type,
                                                 const uint8_t *Data,
                                                 RelExpr RelExpr) const {
   if (Type != R_X86_64_GOTPCRELX && Type != R_X86_64_REX_GOTPCRELX)

lld/trunk/test/ELF/invalid/invalid-relocation-x64.s

Relocations:
       - Offset:          0x0000000000000000
         Symbol:          ''
         Type:            R_X86_64_NONE
       - Offset:          0x0000000000000000
         Symbol:          ''
         Type:            R_X86_64_NONE
 
 # RUN: not ld.lld %p/Inputs/invalid-relocation-x64.elf -o %t2 2>&1 | FileCheck %s
-# CHECK: unrecognized reloc 152
-# CHECK: unrecognized reloc 153
+# CHECK: do not know how to handle relocation 'Unknown' (152)
+# CHECK: do not know how to handle relocation 'Unknown' (153)