Implemented sane default for llvm-objdump's relocation Value format

Summary:
"Unknown" for platforms that were not manually added into the switch
did not make sense at all. Now it prints Target + addend for all
elf-machines that were not explicitly mentioned.

Addresses PR21059 and PR25124.

Original author: fedor.sergeev

Reviewers: jyknight, espindola, fedor.sergeev

Reviewed By: jyknight

Subscribers: eraman, dcederman, jfb, dschuff, aheejin, llvm-commits

Differential Revision: https://reviews.llvm.org/D36464

llvm-svn: 333726

1 files changed, 10 insertions, 72 deletions

diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index 48018c36526..a17d7d1758b 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -430,8 +430,6 @@ static std::error_code getRelocationValueString(const ELFObjectFile<ELFT> *Obj,
   if (!StrTabOrErr)
     return errorToErrorCode(StrTabOrErr.takeError());
   StringRef StrTab = *StrTabOrErr;
-  uint8_t type = RelRef.getType();
-  StringRef res;
   int64_t addend = 0;
   switch (Sec->sh_type) {
   default:
@@ -464,76 +462,16 @@ static std::error_code getRelocationValueString(const ELFObjectFile<ELFT> *Obj,
       return errorToErrorCode(SymName.takeError());
     Target = *SymName;
   }
-  switch (EF.getHeader()->e_machine) {
-  case ELF::EM_X86_64:
-    switch (type) {
-    case ELF::R_X86_64_PC8:
-    case ELF::R_X86_64_PC16:
-    case ELF::R_X86_64_PC32: {
-      std::string fmtbuf;
-      raw_string_ostream fmt(fmtbuf);
-      fmt << Target << (addend < 0 ? "" : "+") << addend << "-P";
-      fmt.flush();
-      Result.append(fmtbuf.begin(), fmtbuf.end());
-    } break;
-    case ELF::R_X86_64_8:
-    case ELF::R_X86_64_16:
-    case ELF::R_X86_64_32:
-    case ELF::R_X86_64_32S:
-    case ELF::R_X86_64_64: {
-      std::string fmtbuf;
-      raw_string_ostream fmt(fmtbuf);
-      fmt << Target << (addend < 0 ? "" : "+") << addend;
-      fmt.flush();
-      Result.append(fmtbuf.begin(), fmtbuf.end());
-    } break;
-    default:
-      res = "Unknown";
-    }
-    break;
-  case ELF::EM_LANAI:
-  case ELF::EM_AVR:
-  case ELF::EM_AARCH64: {
-    std::string fmtbuf;
-    raw_string_ostream fmt(fmtbuf);
-    fmt << Target;
-    if (addend != 0)
-      fmt << (addend < 0 ? "" : "+") << addend;
-    fmt.flush();
-    Result.append(fmtbuf.begin(), fmtbuf.end());
-    break;
-  }
-  case ELF::EM_386:
-  case ELF::EM_IAMCU:
-  case ELF::EM_ARM:
-  case ELF::EM_HEXAGON:
-  case ELF::EM_MIPS:
-  case ELF::EM_BPF:
-  case ELF::EM_RISCV:
-    res = Target;
-    break;
-  case ELF::EM_WEBASSEMBLY:
-    switch (type) {
-    case ELF::R_WEBASSEMBLY_DATA: {
-      std::string fmtbuf;
-      raw_string_ostream fmt(fmtbuf);
-      fmt << Target << (addend < 0 ? "" : "+") << addend;
-      fmt.flush();
-      Result.append(fmtbuf.begin(), fmtbuf.end());
-      break;
-    }
-    case ELF::R_WEBASSEMBLY_FUNCTION:
-      res = Target;
-      break;
-    default:
-      res = "Unknown";
-    }
-    break;
-  default:
-    res = "Unknown";
-  }
-  if (Result.empty())
-    Result.append(res.begin(), res.end());
+
+  // Default scheme is to print Target, as well as "+ <addend>" for nonzero
+  // addend. Should be acceptable for all normal purposes.
+  std::string fmtbuf;
+  raw_string_ostream fmt(fmtbuf);
+  fmt << Target;
+  if (addend != 0)
+    fmt << (addend < 0 ? "" : "+") << addend;
+  fmt.flush();
+  Result.append(fmtbuf.begin(), fmtbuf.end());
   return std::error_code();
 }