[llvm] [BOLT][NFC] Refactor relocation printing (PR #88180)

[Nathan Sidwell via llvm-commits]

https://github.com/urnathan created https://github.com/llvm/llvm-project/pull/88180

I noticed a little more refactoring could be done here.
1) Make the arrays themselves const -- not just the strings being pointed to
2) Move each relocation array to the case using it.
3) Add a suitable assert, to make sure there's no out-of-bounds indexing.

>From 4dac4fd1cba188d6e7527ac62885872917847b9e Mon Sep 17 00:00:00 2001
From: Nathan Sidwell <nathan at acm.org>
Date: Tue, 9 Apr 2024 15:00:10 -0400
Subject: [PATCH] [BOLT][NFC] Refactor relocation printing

---
 bolt/lib/Core/Relocation.cpp | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/bolt/lib/Core/Relocation.cpp b/bolt/lib/Core/Relocation.cpp
index d16b7a94787c65..4e888a5b147aca 100644
--- a/bolt/lib/Core/Relocation.cpp
+++ b/bolt/lib/Core/Relocation.cpp
@@ -1064,21 +1064,19 @@ MCBinaryExpr::Opcode Relocation::getComposeOpcodeFor(uint64_t Type) {
   }
 }
 
-#define ELF_RELOC(name, value) #name,
-
 void Relocation::print(raw_ostream &OS) const {
-  static const char *X86RelocNames[] = {
-#include "llvm/BinaryFormat/ELFRelocs/x86_64.def"
-  };
-  static const char *AArch64RelocNames[] = {
-#include "llvm/BinaryFormat/ELFRelocs/AArch64.def"
-  };
   switch (Arch) {
   default:
     OS << "RType:" << Twine::utohexstr(Type);
     break;
 
   case Triple::aarch64:
+    static const char *const AArch64RelocNames[] = {
+#define ELF_RELOC(name, value) #name,
+#include "llvm/BinaryFormat/ELFRelocs/AArch64.def"
+#undef ELF_RELOC
+    };
+    assert(Type < ArrayRef(AArch64RelocNames).size());
     OS << AArch64RelocNames[Type];
     break;
 
@@ -1088,16 +1086,22 @@ void Relocation::print(raw_ostream &OS) const {
     switch (Type) {
     default:
       llvm_unreachable("illegal RISC-V relocation");
-#undef ELF_RELOC
 #define ELF_RELOC(name, value)                                                 \
   case value:                                                                  \
     OS << #name;                                                               \
     break;
 #include "llvm/BinaryFormat/ELFRelocs/RISCV.def"
+#undef ELF_RELOC
     }
     break;
 
   case Triple::x86_64:
+    static const char *const X86RelocNames[] = {
+#define ELF_RELOC(name, value) #name,
+#include "llvm/BinaryFormat/ELFRelocs/x86_64.def"
+#undef ELF_RELOC
+    };
+    assert(Type < ArrayRef(X86RelocNames).size());
     OS << X86RelocNames[Type];
     break;
   }