From f676cdd515d664e93ecbf8506af9610250195827 Mon Sep 17 00:00:00 2001
From: Sam Clegg <sbc@chromium.org>
Date: Thu, 26 Apr 2018 16:41:51 +0000
Subject: [PATCH] [WebAssembly] Implement getRelocationValueString()

And use it in llvm-objdump.

Differential Revision: https://reviews.llvm.org/D46092

llvm-svn: 330957
---
 llvm/lib/Object/WasmObjectFile.cpp                        | 12 ++++++++----
 llvm/test/Object/objdump-relocations.test                 |  6 +++---
 llvm/test/tools/llvm-objdump/WebAssembly/relocations.test |  2 +-
 llvm/tools/llvm-objdump/llvm-objdump.cpp                  | 10 +++++++++-
 4 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index 3e8f73d..e6b7dde 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -1139,10 +1139,14 @@ uint64_t WasmObjectFile::getRelocationOffset(DataRefImpl Ref) const {
   return Rel.Offset;
 }
 
-symbol_iterator WasmObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
-  llvm_unreachable("not yet implemented");
-  SymbolRef Ref;
-  return symbol_iterator(Ref);
+symbol_iterator WasmObjectFile::getRelocationSymbol(DataRefImpl Ref) const {
+  const wasm::WasmRelocation &Rel = getWasmRelocation(Ref);
+  if (Rel.Type == wasm::R_WEBASSEMBLY_TYPE_INDEX_LEB)
+    return symbol_end();
+  DataRefImpl Sym;
+  Sym.d.a = Rel.Index;
+  Sym.d.b = 0;
+  return symbol_iterator(SymbolRef(Sym, this));
 }
 
 uint64_t WasmObjectFile::getRelocationType(DataRefImpl Ref) const {
diff --git a/llvm/test/Object/objdump-relocations.test b/llvm/test/Object/objdump-relocations.test
index a08fc71..580a2a47 100644
--- a/llvm/test/Object/objdump-relocations.test
+++ b/llvm/test/Object/objdump-relocations.test
@@ -60,9 +60,9 @@ ELF-MIPSEL: R_MIPS_CALL16 puts
 ELF-MIPSEL: R_MIPS_CALL16 SomeOtherFunction
 
 WASM:      CODE
-WASM-NEXT: R_WEBASSEMBLY_MEMORY_ADDR_SLEB 1+0
-WASM-NEXT: R_WEBASSEMBLY_FUNCTION_INDEX_LEB 2+0
-WASM-NEXT: R_WEBASSEMBLY_FUNCTION_INDEX_LEB 3+0
+WASM-NEXT: R_WEBASSEMBLY_MEMORY_ADDR_SLEB .L.str+0
+WASM-NEXT: R_WEBASSEMBLY_FUNCTION_INDEX_LEB puts+0
+WASM-NEXT: R_WEBASSEMBLY_FUNCTION_INDEX_LEB SomeOtherFunction+0
 
 ELF-complex-x86-64: .text
 ELF-complex-x86-64-NEXT: R_X86_64_8 .data-4
diff --git a/llvm/test/tools/llvm-objdump/WebAssembly/relocations.test b/llvm/test/tools/llvm-objdump/WebAssembly/relocations.test
index 25628a5..4f4c1b5 100644
--- a/llvm/test/tools/llvm-objdump/WebAssembly/relocations.test
+++ b/llvm/test/tools/llvm-objdump/WebAssembly/relocations.test
@@ -5,4 +5,4 @@
 @bar = hidden global i32* @foo2, align 4
 
 ; CHECK:      RELOCATION RECORDS FOR [DATA]:
-; CHECK-NEXT: 00000018 R_WEBASSEMBLY_MEMORY_ADDR_I32 1+0
+; CHECK-NEXT: 00000018 R_WEBASSEMBLY_MEMORY_ADDR_I32 foo2+0
diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index 5bea3a7..f32ff06 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -917,9 +917,17 @@ static std::error_code getRelocationValueString(const WasmObjectFile *Obj,
                                                 const RelocationRef &RelRef,
                                                 SmallVectorImpl<char> &Result) {
   const wasm::WasmRelocation& Rel = Obj->getWasmRelocation(RelRef);
+  symbol_iterator SI = RelRef.getSymbol();
   std::string fmtbuf;
   raw_string_ostream fmt(fmtbuf);
-  fmt << Rel.Index << (Rel.Addend < 0 ? "" : "+") << Rel.Addend;
+  Expected<StringRef> SymNameOrErr = SI->getName();
+  if (!SymNameOrErr) {
+    fmt << Rel.Index;
+  } else {
+    StringRef SymName = *SymNameOrErr;
+    Result.append(SymName.begin(), SymName.end());
+  }
+  fmt << (Rel.Addend < 0 ? "" : "+") << Rel.Addend;
   fmt.flush();
   Result.append(fmtbuf.begin(), fmtbuf.end());
   return std::error_code();
-- 
2.7.4