3 files changed, 124 insertions, 96 deletions

diff --git a/contrib/llvm/lib/Object/ModuleSymbolTable.cpp b/contrib/llvm/lib/Object/ModuleSymbolTable.cpp
index 64446525b916..f0d70aefd426 100644
--- a/contrib/llvm/lib/Object/ModuleSymbolTable.cpp
+++ b/contrib/llvm/lib/Object/ModuleSymbolTable.cpp
@@ -24,7 +24,6 @@
 #include "llvm/IR/GlobalAlias.h"
 #include "llvm/IR/GlobalValue.h"
 #include "llvm/IR/GlobalVariable.h"
-#include "llvm/IR/Mangler.h"
 #include "llvm/IR/Module.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
@@ -69,81 +68,6 @@ void ModuleSymbolTable::addModule(Module *M) {
   });
 }
 
-// Ensure ELF .symver aliases get the same binding as the defined symbol
-// they alias with.
-static void handleSymverAliases(const Module &M, RecordStreamer &Streamer) {
-  if (Streamer.symverAliases().empty())
-    return;
-
-  // The name in the assembler will be mangled, but the name in the IR
-  // might not, so we first compute a mapping from mangled name to GV.
-  Mangler Mang;
-  SmallString<64> MangledName;
-  StringMap<const GlobalValue *> MangledNameMap;
-  auto GetMangledName = [&](const GlobalValue &GV) {
-    if (!GV.hasName())
-      return;
-
-    MangledName.clear();
-    MangledName.reserve(GV.getName().size() + 1);
-    Mang.getNameWithPrefix(MangledName, &GV, /*CannotUsePrivateLabel=*/false);
-    MangledNameMap[MangledName] = &GV;
-  };
-  for (const Function &F : M)
-    GetMangledName(F);
-  for (const GlobalVariable &GV : M.globals())
-    GetMangledName(GV);
-  for (const GlobalAlias &GA : M.aliases())
-    GetMangledName(GA);
-
-  // Walk all the recorded .symver aliases, and set up the binding
-  // for each alias.
-  for (auto &Symver : Streamer.symverAliases()) {
-    const MCSymbol *Aliasee = Symver.first;
-    MCSymbolAttr Attr = MCSA_Invalid;
-
-    // First check if the aliasee binding was recorded in the asm.
-    RecordStreamer::State state = Streamer.getSymbolState(Aliasee);
-    switch (state) {
-    case RecordStreamer::Global:
-    case RecordStreamer::DefinedGlobal:
-      Attr = MCSA_Global;
-      break;
-    case RecordStreamer::UndefinedWeak:
-    case RecordStreamer::DefinedWeak:
-      Attr = MCSA_Weak;
-      break;
-    default:
-      break;
-    }
-
-    // If we don't have a symbol attribute from assembly, then check if
-    // the aliasee was defined in the IR.
-    if (Attr == MCSA_Invalid) {
-      const auto *GV = M.getNamedValue(Aliasee->getName());
-      if (!GV) {
-        auto MI = MangledNameMap.find(Aliasee->getName());
-        if (MI != MangledNameMap.end())
-          GV = MI->second;
-        else
-          continue;
-      }
-      if (GV->hasExternalLinkage())
-        Attr = MCSA_Global;
-      else if (GV->hasLocalLinkage())
-        Attr = MCSA_Local;
-      else if (GV->isWeakForLinker())
-        Attr = MCSA_Weak;
-    }
-    if (Attr == MCSA_Invalid)
-      continue;
-
-    // Set the detected binding on each alias with this aliasee.
-    for (auto &Alias : Symver.second)
-      Streamer.EmitSymbolAttribute(Alias, Attr);
-  }
-}
-
 void ModuleSymbolTable::CollectAsmSymbols(
     const Module &M,
     function_ref<void(StringRef, BasicSymbolRef::Flags)> AsmSymbol) {
@@ -176,7 +100,7 @@ void ModuleSymbolTable::CollectAsmSymbols(
   MCObjectFileInfo MOFI;
   MCContext MCCtx(MAI.get(), MRI.get(), &MOFI);
   MOFI.InitMCObjectFileInfo(TT, /*PIC*/ false, MCCtx);
-  RecordStreamer Streamer(MCCtx);
+  RecordStreamer Streamer(MCCtx, M);
   T->createNullTargetStreamer(Streamer);
 
   std::unique_ptr<MemoryBuffer> Buffer(MemoryBuffer::getMemBuffer(InlineAsm));
@@ -195,7 +119,7 @@ void ModuleSymbolTable::CollectAsmSymbols(
   if (Parser->Run(false))
     return;
 
-  handleSymverAliases(M, Streamer);
+  Streamer.flushSymverDirectives();
 
   for (auto &KV : Streamer) {
     StringRef Key = KV.first();
diff --git a/contrib/llvm/lib/Object/RecordStreamer.cpp b/contrib/llvm/lib/Object/RecordStreamer.cpp
index e94e9cfed394..74130901d325 100644
--- a/contrib/llvm/lib/Object/RecordStreamer.cpp
+++ b/contrib/llvm/lib/Object/RecordStreamer.cpp
@@ -8,6 +8,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "RecordStreamer.h"
+#include "llvm/IR/Mangler.h"
+#include "llvm/IR/Module.h"
+#include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCSymbol.h"
 
 using namespace llvm;
@@ -70,7 +73,8 @@ void RecordStreamer::markUsed(const MCSymbol &Symbol) {
 
 void RecordStreamer::visitUsedSymbol(const MCSymbol &Sym) { markUsed(Sym); }
 
-RecordStreamer::RecordStreamer(MCContext &Context) : MCStreamer(Context) {}
+RecordStreamer::RecordStreamer(MCContext &Context, const Module &M)
+    : MCStreamer(Context), M(M) {}
 
 RecordStreamer::const_iterator RecordStreamer::begin() {
   return Symbols.begin();
@@ -112,7 +116,109 @@ void RecordStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
   markDefined(*Symbol);
 }
 
-void RecordStreamer::emitELFSymverDirective(MCSymbol *Alias,
+RecordStreamer::State RecordStreamer::getSymbolState(const MCSymbol *Sym) {
+  auto SI = Symbols.find(Sym->getName());
+  if (SI == Symbols.end())
+    return NeverSeen;
+  return SI->second;
+}
+
+void RecordStreamer::emitELFSymverDirective(StringRef AliasName,
                                             const MCSymbol *Aliasee) {
-  SymverAliasMap[Aliasee].push_back(Alias);
+  SymverAliasMap[Aliasee].push_back(AliasName);
+}
+
+void RecordStreamer::flushSymverDirectives() {
+  // Mapping from mangled name to GV.
+  StringMap<const GlobalValue *> MangledNameMap;
+  // The name in the assembler will be mangled, but the name in the IR
+  // might not, so we first compute a mapping from mangled name to GV.
+  Mangler Mang;
+  SmallString<64> MangledName;
+  for (const GlobalValue &GV : M.global_values()) {
+    if (!GV.hasName())
+      continue;
+    MangledName.clear();
+    MangledName.reserve(GV.getName().size() + 1);
+    Mang.getNameWithPrefix(MangledName, &GV, /*CannotUsePrivateLabel=*/false);
+    MangledNameMap[MangledName] = &GV;
+  }
+
+  // Walk all the recorded .symver aliases, and set up the binding
+  // for each alias.
+  for (auto &Symver : SymverAliasMap) {
+    const MCSymbol *Aliasee = Symver.first;
+    MCSymbolAttr Attr = MCSA_Invalid;
+    bool IsDefined = false;
+
+    // First check if the aliasee binding was recorded in the asm.
+    RecordStreamer::State state = getSymbolState(Aliasee);
+    switch (state) {
+    case RecordStreamer::Global:
+    case RecordStreamer::DefinedGlobal:
+      Attr = MCSA_Global;
+      break;
+    case RecordStreamer::UndefinedWeak:
+    case RecordStreamer::DefinedWeak:
+      Attr = MCSA_Weak;
+      break;
+    default:
+      break;
+    }
+
+    switch (state) {
+    case RecordStreamer::Defined:
+    case RecordStreamer::DefinedGlobal:
+    case RecordStreamer::DefinedWeak:
+      IsDefined = true;
+      break;
+    case RecordStreamer::NeverSeen:
+    case RecordStreamer::Global:
+    case RecordStreamer::Used:
+    case RecordStreamer::UndefinedWeak:
+      break;
+    }
+
+    if (Attr == MCSA_Invalid || !IsDefined) {
+      const GlobalValue *GV = M.getNamedValue(Aliasee->getName());
+      if (!GV) {
+        auto MI = MangledNameMap.find(Aliasee->getName());
+        if (MI != MangledNameMap.end())
+          GV = MI->second;
+      }
+      if (GV) {
+        // If we don't have a symbol attribute from assembly, then check if
+        // the aliasee was defined in the IR.
+        if (Attr == MCSA_Invalid) {
+          if (GV->hasExternalLinkage())
+            Attr = MCSA_Global;
+          else if (GV->hasLocalLinkage())
+            Attr = MCSA_Local;
+          else if (GV->isWeakForLinker())
+            Attr = MCSA_Weak;
+        }
+        IsDefined = IsDefined || !GV->isDeclarationForLinker();
+      }
+    }
+
+    // Set the detected binding on each alias with this aliasee.
+    for (auto AliasName : Symver.second) {
+      std::pair<StringRef, StringRef> Split = AliasName.split("@@@");
+      SmallString<128> NewName;
+      if (!Split.second.empty() && !Split.second.startswith("@")) {
+        // Special processing for "@@@" according
+        // https://sourceware.org/binutils/docs/as/Symver.html
+        const char *Separator = IsDefined ? "@@" : "@";
+        AliasName =
+            (Split.first + Separator + Split.second).toStringRef(NewName);
+      }
+      MCSymbol *Alias = getContext().getOrCreateSymbol(AliasName);
+      // TODO: Handle "@@@". Depending on SymbolAttribute value it needs to be
+      // converted into @ or @@.
+      const MCExpr *Value = MCSymbolRefExpr::create(Aliasee, getContext());
+      EmitAssignment(Alias, Value);
+      if (Attr != MCSA_Invalid)
+        EmitSymbolAttribute(Alias, Attr);
+    }
+  }
 }
diff --git a/contrib/llvm/lib/Object/RecordStreamer.h b/contrib/llvm/lib/Object/RecordStreamer.h
index 4d119091a3d2..60b2d3ec3e8e 100644
--- a/contrib/llvm/lib/Object/RecordStreamer.h
+++ b/contrib/llvm/lib/Object/RecordStreamer.h
@@ -20,17 +20,24 @@
 
 namespace llvm {
 
+class GlobalValue;
+class Module;
+
 class RecordStreamer : public MCStreamer {
 public:
   enum State { NeverSeen, Global, Defined, DefinedGlobal, DefinedWeak, Used,
                UndefinedWeak};
 
 private:
+  const Module &M;
   StringMap<State> Symbols;
   // Map of aliases created by .symver directives, saved so we can update
   // their symbol binding after parsing complete. This maps from each
   // aliasee to its list of aliases.
-  DenseMap<const MCSymbol *, std::vector<MCSymbol *>> SymverAliasMap;
+  DenseMap<const MCSymbol *, std::vector<StringRef>> SymverAliasMap;
+
+  /// Get the state recorded for the given symbol.
+  State getSymbolState(const MCSymbol *Sym);
 
   void markDefined(const MCSymbol &Symbol);
   void markGlobal(const MCSymbol &Symbol, MCSymbolAttr Attribute);
@@ -38,7 +45,7 @@ private:
   void visitUsedSymbol(const MCSymbol &Sym) override;
 
 public:
-  RecordStreamer(MCContext &Context);
+  RecordStreamer(MCContext &Context, const Module &M);
 
   using const_iterator = StringMap<State>::const_iterator;
 
@@ -54,20 +61,11 @@ public:
   void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                         unsigned ByteAlignment) override;
   /// Record .symver aliases for later processing.
-  void emitELFSymverDirective(MCSymbol *Alias,
+  void emitELFSymverDirective(StringRef AliasName,
                               const MCSymbol *Aliasee) override;
-  /// Return the map of .symver aliasee to associated aliases.
-  DenseMap<const MCSymbol *, std::vector<MCSymbol *>> &symverAliases() {
-    return SymverAliasMap;
-  }
-
-  /// Get the state recorded for the given symbol.
-  State getSymbolState(const MCSymbol *Sym) {
-    auto SI = Symbols.find(Sym->getName());
-    if (SI == Symbols.end())
-      return NeverSeen;
-    return SI->second;
-  }
+  // Emit ELF .symver aliases and ensure they have the same binding as the
+  // defined symbol they alias with.
+  void flushSymverDirectives();
 };
 
 } // end namespace llvm