[LLD][ELF] - Improve diagnostic about unrecognized relocations.

[grimar]

Summary

This is a minor improvement inspired by https://bugs.llvm.org/show_bug.cgi?id=38303.

A person reported that he observed message complaining about unsupported R_ARM_V4BX:
error: can't create dynamic relocation R_ARM_V4BX against local symbol in readonly segment; recompile object files with -fPIC

But with -z notext he only saw a relocation number, what is not convenient:
error: ../../gfx/cairo/libpixman/src/pixman-arm-neon-asm-bilinear.o:(.text+0x4F0): unrecognized reloc 40

Also, in the error messages we use relocation but not reloc.

With this patch we start to print one of the following messages:
error: file.o: unrecognized relocation Unknown(999)
error: file.o: unrecognized relocation R_X_KNOWN_BY_LLVM_BUT_UNSUPPORTED_BY_LLD_NAME

There is no way to write a test for that I believe.

[MaskRay]

LG

ELF/Arch/AArch64.cpp

case R_AARCH64_TLSLE_ADD_TPREL_HI12:
     checkUInt(Loc, Val, 24, Type);
     or32AArch64Imm(Loc, Val >> 12);
     break;
   case R_AARCH64_TLSLE_ADD_TPREL_LO12_NC:
   case R_AARCH64_TLSDESC_ADD_LO12:
     or32AArch64Imm(Loc, Val);
     break;
   default:
-    error(getErrorLocation(Loc) + "unrecognized reloc " + Twine(Type));
+    error(getErrorLocation(Loc) + "unrecognized relocation " + toString(Type));
   }
 }
 
 void AArch64::relaxTlsGdToLe(uint8_t *Loc, RelType Type, uint64_t Val) const {
   // TLSDESC Global-Dynamic relocation are in the form:
   //   adrp    x0, :tlsdesc:v             [R_AARCH64_TLSDESC_ADR_PAGE21]
   //   ldr     x1, [x0, #:tlsdesc_lo12:v  [R_AARCH64_TLSDESC_LD64_LO12]
   //   add     x0, x0, :tlsdesc_los:v     [R_AARCH64_TLSDESC_ADD_LO12]

ELF/Arch/ARM.cpp

write16le(Loc,
                   ((Val >> 1) & 0x0400) |  // i
                   ((Val >> 12) & 0x000f)); // imm4
     write16le(Loc + 2,
               (read16le(Loc + 2) & 0x8f00) | // opcode
                   ((Val << 4) & 0x7000) |    // imm3
                   (Val & 0x00ff));           // imm8
     break;
   default:
-    error(getErrorLocation(Loc) + "unrecognized reloc " + Twine(Type));
+    error(getErrorLocation(Loc) + "unrecognized relocation " + toString(Type));
   }
 }
 
 int64_t ARM::getImplicitAddend(const uint8_t *Buf, RelType Type) const {
   switch (Type) {
   default:
     return 0;
   case R_ARM_ABS32:

ELF/Arch/AVR.cpp

void AVR::relocateOne(uint8_t *Loc, RelType Type, uint64_t Val) const {
   case R_AVR_CALL: {
     uint16_t Hi = Val >> 17;
     uint16_t Lo = Val >> 1;
     write16le(Loc, read16le(Loc) | ((Hi >> 1) << 4) | (Hi & 1));
     write16le(Loc + 2, Lo);
     break;
   }
   default:
-    error(getErrorLocation(Loc) + "unrecognized reloc " + toString(Type));
+    error(getErrorLocation(Loc) + "unrecognized relocation " + toString(Type));
   }
 }
 
 TargetInfo *elf::getAVRTargetInfo() {
   static AVR Target;
   return &Target;
 }

ELF/Arch/Hexagon.cpp

case R_HEX_B32_PCREL_X:
     break;
   case R_HEX_HI16:
     or32le(Loc, applyMask(0x00c03fff, Val >> 16));
     break;
   case R_HEX_LO16:
     or32le(Loc, applyMask(0x00c03fff, Val));
     break;
   default:
-    error(getErrorLocation(Loc) + "unrecognized reloc " + toString(Type));
+    error(getErrorLocation(Loc) + "unrecognized relocation " + toString(Type));
     break;
   }
 }
 
 void Hexagon::writePltHeader(uint8_t *Buf) const {
   const uint8_t PltData[] = {
       0x00, 0x40, 0x00, 0x00, // { immext (#0)
       0x1c, 0xc0, 0x49, 0x6a, //   r28 = add (pc, ##GOT0@PCREL) } # @GOT0

ELF/Arch/MSP430.cpp

case R_MSP430_32:
     break;
   case R_MSP430_10_PCREL: {
     int16_t Offset = ((int16_t)Val >> 1) - 1;
     checkInt(Loc, Offset, 10, Type);
     write16le(Loc, (read16le(Loc) & 0xFC00) | (Offset & 0x3FF));
     break;
   }
   default:
-    error(getErrorLocation(Loc) + "unrecognized reloc " + toString(Type));
+    error(getErrorLocation(Loc) + "unrecognized relocation " + toString(Type));
   }
 }
 
 TargetInfo *elf::getMSP430TargetInfo() {
   static MSP430 Target;
   return &Target;
 }

ELF/Arch/PPC.cpp

void PPC::relocateOne(uint8_t *Loc, RelType Type, uint64_t Val) const {
   case R_PPC_REL14:
     write32be(Loc, read32be(Loc) | (Val & 0xFFFC));
     break;
   case R_PPC_PLTREL24:
   case R_PPC_REL24:
     write32be(Loc, read32be(Loc) | (Val & 0x3FFFFFC));
     break;
   default:
-    error(getErrorLocation(Loc) + "unrecognized reloc " + Twine(Type));
+    error(getErrorLocation(Loc) + "unrecognized relocation " + toString(Type));
   }
 }
 
 TargetInfo *elf::getPPCTargetInfo() {
   static PPC Target;
   return &Target;
 }

ELF/Arch/PPC64.cpp

case R_PPC64_REL24: {
     checkAlignment(Loc, Val, 4, Type);
     write32(Loc, (read32(Loc) & ~Mask) | (Val & Mask));
     break;
   }
   case R_PPC64_DTPREL64:
     write64(Loc, Val - DynamicThreadPointerOffset);
     break;
   default:
-    error(getErrorLocation(Loc) + "unrecognized reloc " + Twine(Type));
+    error(getErrorLocation(Loc) + "unrecognized relocation " + toString(Type));
   }
 }
 
 bool PPC64::needsThunk(RelExpr Expr, RelType Type, const InputFile *File,
                        uint64_t BranchAddr, const Symbol &S) const {
   if (Type != R_PPC64_REL14 && Type != R_PPC64_REL24)
     return false;