Don't lookup an object symbol name in the module.

Instead, walk the obj symbol list in parallel to find the GV. This shouldn't
change anything on ELF where global symbols are not mangled, but it is a step
toward supporting other object formats.

Gold itself is ELF only, but bfd ld supports COFF and the logic in the gold
plugin could be reused on lld.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223780 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Object/IRObjectFile.h b/include/llvm/Object/IRObjectFile.h
index b650d5d32934994731bdc7ad40273114a5a78bc5..10ea05ddf1f7913cfe6e45124d72e817450ab573 100644 (file)
--- a/include/llvm/Object/IRObjectFile.h
+++ b/include/llvm/Object/IRObjectFile.h
@@ -36,7 +36,10 @@ public:
   std::error_code printSymbolName(raw_ostream &OS,
                                   DataRefImpl Symb) const override;
   uint32_t getSymbolFlags(DataRefImpl Symb) const override;
-  const GlobalValue *getSymbolGV(DataRefImpl Symb) const;
+  GlobalValue *getSymbolGV(DataRefImpl Symb);
+  const GlobalValue *getSymbolGV(DataRefImpl Symb) const {
+    return const_cast<IRObjectFile *>(this)->getSymbolGV(Symb);
+  }
   basic_symbol_iterator symbol_begin_impl() const override;
   basic_symbol_iterator symbol_end_impl() const override;
 
@@ -46,6 +49,7 @@ public:
   Module &getModule() {
     return *M;
   }
+  std::unique_ptr<Module> takeModule() { return std::move(M); }
 
   static inline bool classof(const Binary *v) {
     return v->isIR();

diff --git a/lib/Object/IRObjectFile.cpp b/lib/Object/IRObjectFile.cpp
index 7256a2fc0076a2c56bdfdbeac199583c44e27d9c..84b6c95f2c71be674ad9745dfa79324b164d3499 100644 (file)
--- a/lib/Object/IRObjectFile.cpp
+++ b/lib/Object/IRObjectFile.cpp
@@ -116,7 +116,7 @@ IRObjectFile::IRObjectFile(MemoryBufferRef Object, std::unique_ptr<Module> Mod)
 IRObjectFile::~IRObjectFile() {
  }
 
-static const GlobalValue *getGV(DataRefImpl &Symb) {
+static GlobalValue *getGV(DataRefImpl &Symb) {
   if ((Symb.p & 3) == 3)
     return nullptr;
 
@@ -235,10 +235,7 @@ uint32_t IRObjectFile::getSymbolFlags(DataRefImpl Symb) const {
   return Res;
 }
 
-const GlobalValue *IRObjectFile::getSymbolGV(DataRefImpl Symb) const {
-  const GlobalValue *GV = getGV(Symb);
-  return GV;
-}
+GlobalValue *IRObjectFile::getSymbolGV(DataRefImpl Symb) { return getGV(Symb); }
 
 basic_symbol_iterator IRObjectFile::symbol_begin_impl() const {
   Module::const_iterator I = M->begin();

diff --git a/tools/gold/gold-plugin.cpp b/tools/gold/gold-plugin.cpp
index b7d8c5e14c688ee3fc350a992742aa41cba3b79a..972dbd323655c1d187c129a220f99a3978c848da 100644 (file)
--- a/tools/gold/gold-plugin.cpp
+++ b/tools/gold/gold-plugin.cpp
@@ -261,6 +261,14 @@ static const GlobalObject *getBaseObject(const GlobalValue &GV) {
   return cast<GlobalObject>(&GV);
 }
 
+static bool shouldSkip(uint32_t Symflags) {
+  if (!(Symflags & object::BasicSymbolRef::SF_Global))
+    return true;
+  if (Symflags & object::BasicSymbolRef::SF_FormatSpecific)
+    return true;
+  return false;
+}
+
 /// Called by gold to see whether this file is one that our plugin can handle.
 /// We'll try to open it and register all the symbols with add_symbol if
 /// possible.
@@ -318,10 +326,7 @@ static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
 
   for (auto &Sym : Obj->symbols()) {
     uint32_t Symflags = Sym.getFlags();
-    if (!(Symflags & object::BasicSymbolRef::SF_Global))
-      continue;
-
-    if (Symflags & object::BasicSymbolRef::SF_FormatSpecific)
+    if (shouldSkip(Symflags))
       continue;
 
     cf.syms.push_back(ld_plugin_symbol());
@@ -556,40 +561,41 @@ getModuleForFile(LLVMContext &Context, claimed_file &F, raw_fd_ostream *ApiFile,
   if (get_view(F.handle, &View) != LDPS_OK)
     message(LDPL_FATAL, "Failed to get a view of file");
 
-  llvm::ErrorOr<MemoryBufferRef> MBOrErr =
-      object::IRObjectFile::findBitcodeInMemBuffer(
-          MemoryBufferRef(StringRef((const char *)View, File.filesize), ""));
-  if (std::error_code EC = MBOrErr.getError())
+  MemoryBufferRef BufferRef(StringRef((const char *)View, File.filesize), "");
+  ErrorOr<std::unique_ptr<object::IRObjectFile>> ObjOrErr =
+      object::IRObjectFile::createIRObjectFile(BufferRef, Context);
+
+  if (std::error_code EC = ObjOrErr.getError())
     message(LDPL_FATAL, "Could not read bitcode from file : %s",
             EC.message().c_str());
 
-  std::unique_ptr<MemoryBuffer> Buffer =
-      MemoryBuffer::getMemBuffer(MBOrErr->getBuffer(), "", false);
-
   if (release_input_file(F.handle) != LDPS_OK)
     message(LDPL_FATAL, "Failed to release file information");
 
-  ErrorOr<Module *> MOrErr = getLazyBitcodeModule(std::move(Buffer), Context);
-
-  if (std::error_code EC = MOrErr.getError())
-    message(LDPL_FATAL, "Could not read bitcode from file : %s",
-            EC.message().c_str());
+  object::IRObjectFile &Obj = **ObjOrErr;
 
-  std::unique_ptr<Module> M(MOrErr.get());
+  Module &M = Obj.getModule();
 
   SmallPtrSet<GlobalValue *, 8> Used;
-  collectUsedGlobalVariables(*M, Used, /*CompilerUsed*/ false);
+  collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
 
   DenseSet<GlobalValue *> Drop;
   std::vector<GlobalAlias *> KeptAliases;
-  for (ld_plugin_symbol &Sym : F.syms) {
+
+  unsigned SymNum = 0;
+  for (auto &ObjSym : Obj.symbols()) {
+    if (shouldSkip(ObjSym.getFlags()))
+      continue;
+    ld_plugin_symbol &Sym = F.syms[SymNum];
+    ++SymNum;
+
     ld_plugin_symbol_resolution Resolution =
         (ld_plugin_symbol_resolution)Sym.resolution;
 
     if (options::generate_api_file)
       *ApiFile << Sym.name << ' ' << getResolutionName(Resolution) << '\n';
 
-    GlobalValue *GV = M->getNamedValue(Sym.name);
+    GlobalValue *GV = Obj.getSymbolGV(ObjSym.getRawDataRefImpl());
     if (!GV)
       continue; // Asm symbol.
 
@@ -671,7 +677,7 @@ getModuleForFile(LLVMContext &Context, claimed_file &F, raw_fd_ostream *ApiFile,
   for (auto *GV : Drop)
     drop(*GV);
 
-  return M;
+  return Obj.takeModule();
 }
 
 static void runLTOPasses(Module &M, TargetMachine &TM) {