1 files changed, 145 insertions, 159 deletions

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index ce8d480a408..3a025f4c026 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -202,33 +202,7 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
   ObjSectionToIDMap LocalSections;
 
   // Common symbols requiring allocation, with their sizes and alignments
-  CommonSymbolList CommonSymbolsToAllocate;
-
-  uint64_t CommonSize = 0;
-  uint32_t CommonAlign = 0;
-
-  // First, collect all weak and common symbols. We need to know if stronger
-  // definitions occur elsewhere.
-  JITSymbolResolver::LookupFlagsResult SymbolFlags;
-  {
-    JITSymbolResolver::SymbolNameSet Symbols;
-    for (auto &Sym : Obj.symbols()) {
-      uint32_t Flags = Sym.getFlags();
-      if ((Flags & SymbolRef::SF_Common) || (Flags & SymbolRef::SF_Weak)) {
-        // Get symbol name.
-        StringRef Name;
-        if (auto NameOrErr = Sym.getName())
-          Symbols.insert(*NameOrErr);
-        else
-          return NameOrErr.takeError();
-      }
-    }
-
-    if (auto FlagsResultOrErr = Resolver.lookupFlags(Symbols))
-      SymbolFlags = std::move(*FlagsResultOrErr);
-    else
-      return FlagsResultOrErr.takeError();
-  }
+  CommonSymbolList CommonSymbols;
 
   // Parse symbols
   DEBUG(dbgs() << "Parse symbols:\n");
@@ -240,108 +214,102 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
     if (Flags & SymbolRef::SF_Undefined)
       continue;
 
-    // Get the symbol type.
-    object::SymbolRef::Type SymType;
-    if (auto SymTypeOrErr = I->getType())
-      SymType = *SymTypeOrErr;
-    else
-      return SymTypeOrErr.takeError();
+    if (Flags & SymbolRef::SF_Common)
+      CommonSymbols.push_back(*I);
+    else {
 
-    // Get symbol name.
-    StringRef Name;
-    if (auto NameOrErr = I->getName())
-      Name = *NameOrErr;
-    else
-      return NameOrErr.takeError();
-
-    // Compute JIT symbol flags.
-    JITSymbolFlags JITSymFlags = getJITSymbolFlags(*I);
-
-    // If this is a weak definition, check to see if there's a strong one.
-    // If there is, skip this symbol (we won't be providing it: the strong
-    // definition will). If there's no strong definition, make this definition
-    // strong.
-    if (JITSymFlags.isWeak() || JITSymFlags.isCommon()) {
-      // First check whether there's already a definition in this instance.
-      // FIXME: Override existing weak definitions with strong ones.
-      if (GlobalSymbolTable.count(Name))
-        continue;
-
-      // Then check whether we found flags for an existing symbol during the
-      // flags lookup earlier.
-      auto FlagsI = SymbolFlags.find(Name);
-      if (FlagsI == SymbolFlags.end() ||
-          (JITSymFlags.isWeak() && !FlagsI->second.isStrong()) ||
-          (JITSymFlags.isCommon() && FlagsI->second.isCommon())) {
-        if (JITSymFlags.isWeak())
-          JITSymFlags &= ~JITSymbolFlags::Weak;
-        if (JITSymFlags.isCommon()) {
-          JITSymFlags &= ~JITSymbolFlags::Common;
-          uint32_t Align = I->getAlignment();
-          uint64_t Size = I->getCommonSize();
-          if (!CommonAlign)
-            CommonAlign = Align;
-          CommonSize += alignTo(CommonSize, Align) + Size;
-          CommonSymbolsToAllocate.push_back(*I);
-        }
-      } else
-        continue;
-    }
-
-    if (Flags & SymbolRef::SF_Absolute &&
-        SymType != object::SymbolRef::ST_File) {
-      uint64_t Addr = 0;
-      if (auto AddrOrErr = I->getAddress())
-        Addr = *AddrOrErr;
+      // Get the symbol type.
+      object::SymbolRef::Type SymType;
+      if (auto SymTypeOrErr = I->getType())
+        SymType =  *SymTypeOrErr;
       else
-        return AddrOrErr.takeError();
-
-      unsigned SectionID = AbsoluteSymbolSection;
-
-      DEBUG(dbgs() << "\tType: " << SymType << " (absolute) Name: " << Name
-                   << " SID: " << SectionID
-                   << " Offset: " << format("%p", (uintptr_t)Addr)
-                   << " flags: " << Flags << "\n");
-      GlobalSymbolTable[Name] = SymbolTableEntry(SectionID, Addr, JITSymFlags);
-    } else if (SymType == object::SymbolRef::ST_Function ||
-               SymType == object::SymbolRef::ST_Data ||
-               SymType == object::SymbolRef::ST_Unknown ||
-               SymType == object::SymbolRef::ST_Other) {
-
-      section_iterator SI = Obj.section_end();
-      if (auto SIOrErr = I->getSection())
-        SI = *SIOrErr;
+        return SymTypeOrErr.takeError();
+
+      // Get symbol name.
+      StringRef Name;
+      if (auto NameOrErr = I->getName())
+        Name = *NameOrErr;
       else
-        return SIOrErr.takeError();
+        return NameOrErr.takeError();
+
+      // Compute JIT symbol flags.
+      JITSymbolFlags JITSymFlags = getJITSymbolFlags(*I);
+
+      // If this is a weak definition, check to see if there's a strong one.
+      // If there is, skip this symbol (we won't be providing it: the strong
+      // definition will). If there's no strong definition, make this definition
+      // strong.
+      if (JITSymFlags.isWeak()) {
+        // First check whether there's already a definition in this instance.
+        // FIXME: Override existing weak definitions with strong ones.
+        if (GlobalSymbolTable.count(Name))
+          continue;
+        // Then check the symbol resolver to see if there's a definition
+        // elsewhere in this logical dylib.
+        if (auto Sym = Resolver.findSymbolInLogicalDylib(Name)) {
+          if (Sym.getFlags().isStrong())
+            continue;
+        } else if (auto Err = Sym.takeError())
+          return std::move(Err);
+        // else
+        JITSymFlags &= ~JITSymbolFlags::Weak;
+      }
 
-      if (SI == Obj.section_end())
-        continue;
+      if (Flags & SymbolRef::SF_Absolute &&
+          SymType != object::SymbolRef::ST_File) {
+        uint64_t Addr = 0;
+        if (auto AddrOrErr = I->getAddress())
+          Addr = *AddrOrErr;
+        else
+          return AddrOrErr.takeError();
+
+        unsigned SectionID = AbsoluteSymbolSection;
+
+        DEBUG(dbgs() << "\tType: " << SymType << " (absolute) Name: " << Name
+                     << " SID: " << SectionID << " Offset: "
+                     << format("%p", (uintptr_t)Addr)
+                     << " flags: " << Flags << "\n");
+        GlobalSymbolTable[Name] =
+          SymbolTableEntry(SectionID, Addr, JITSymFlags);
+      } else if (SymType == object::SymbolRef::ST_Function ||
+                 SymType == object::SymbolRef::ST_Data ||
+                 SymType == object::SymbolRef::ST_Unknown ||
+                 SymType == object::SymbolRef::ST_Other) {
+
+        section_iterator SI = Obj.section_end();
+        if (auto SIOrErr = I->getSection())
+          SI = *SIOrErr;
+        else
+          return SIOrErr.takeError();
 
-      // Get symbol offset.
-      uint64_t SectOffset;
-      if (auto Err = getOffset(*I, *SI, SectOffset))
-        return std::move(Err);
+        if (SI == Obj.section_end())
+          continue;
 
-      bool IsCode = SI->isText();
-      unsigned SectionID;
-      if (auto SectionIDOrErr =
-              findOrEmitSection(Obj, *SI, IsCode, LocalSections))
-        SectionID = *SectionIDOrErr;
-      else
-        return SectionIDOrErr.takeError();
+        // Get symbol offset.
+        uint64_t SectOffset;
+        if (auto Err = getOffset(*I, *SI, SectOffset))
+          return std::move(Err);
+
+        bool IsCode = SI->isText();
+        unsigned SectionID;
+        if (auto SectionIDOrErr = findOrEmitSection(Obj, *SI, IsCode,
+                                                    LocalSections))
+          SectionID = *SectionIDOrErr;
+        else
+          return SectionIDOrErr.takeError();
 
-      DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name
-                   << " SID: " << SectionID
-                   << " Offset: " << format("%p", (uintptr_t)SectOffset)
-                   << " flags: " << Flags << "\n");
-      GlobalSymbolTable[Name] =
+        DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name
+                     << " SID: " << SectionID << " Offset: "
+                     << format("%p", (uintptr_t)SectOffset)
+                     << " flags: " << Flags << "\n");
+        GlobalSymbolTable[Name] =
           SymbolTableEntry(SectionID, SectOffset, JITSymFlags);
+      }
     }
   }
 
   // Allocate common symbols
-  if (auto Err = emitCommonSymbols(Obj, CommonSymbolsToAllocate, CommonSize,
-                                   CommonAlign))
+  if (auto Err = emitCommonSymbols(Obj, CommonSymbols))
     return std::move(Err);
 
   // Parse and process relocations
@@ -653,12 +621,45 @@ JITSymbolFlags RuntimeDyldImpl::getJITSymbolFlags(const BasicSymbolRef &SR) {
 }
 
 Error RuntimeDyldImpl::emitCommonSymbols(const ObjectFile &Obj,
-                                         CommonSymbolList &SymbolsToAllocate,
-                                         uint64_t CommonSize,
-                                         uint32_t CommonAlign) {
-  if (SymbolsToAllocate.empty())
+                                         CommonSymbolList &CommonSymbols) {
+  if (CommonSymbols.empty())
     return Error::success();
 
+  uint64_t CommonSize = 0;
+  uint32_t CommonAlign = CommonSymbols.begin()->getAlignment();
+  CommonSymbolList SymbolsToAllocate;
+
+  DEBUG(dbgs() << "Processing common symbols...\n");
+
+  for (const auto &Sym : CommonSymbols) {
+    StringRef Name;
+    if (auto NameOrErr = Sym.getName())
+      Name = *NameOrErr;
+    else
+      return NameOrErr.takeError();
+
+    // Skip common symbols already elsewhere.
+    if (GlobalSymbolTable.count(Name)) {
+      DEBUG(dbgs() << "\tSkipping already emitted common symbol '" << Name
+                   << "'\n");
+      continue;
+    }
+
+    if (auto Sym = Resolver.findSymbolInLogicalDylib(Name)) {
+      if (!Sym.getFlags().isCommon()) {
+        DEBUG(dbgs() << "\tSkipping common symbol '" << Name
+                     << "' in favor of stronger definition.\n");
+        continue;
+      }
+    }
+    uint32_t Align = Sym.getAlignment();
+    uint64_t Size = Sym.getCommonSize();
+
+    CommonSize = alignTo(CommonSize, Align) + Size;
+
+    SymbolsToAllocate.push_back(Sym);
+  }
+
   // Allocate memory for the section
   unsigned SectionID = Sections.size();
   uint8_t *Addr = MemMgr.allocateDataSection(CommonSize, CommonAlign, SectionID,
@@ -996,40 +997,7 @@ void RuntimeDyldImpl::resolveRelocationList(const RelocationList &Relocs,
 }
 
 Error RuntimeDyldImpl::resolveExternalSymbols() {
-  JITSymbolResolver::LookupResult ExternalSymbolMap;
-
-  // Resolution can trigger emission of more symbols, so iterate until
-  // we've resolved *everything*.
-  {
-    JITSymbolResolver::SymbolNameSet ResolvedSymbols;
-
-    while (true) {
-      JITSymbolResolver::SymbolNameSet NewSymbols;
-
-      for (auto &RelocKV : ExternalSymbolRelocations) {
-        StringRef Name = RelocKV.first();
-        if (!Name.empty() && !GlobalSymbolTable.count(Name) &&
-            !ResolvedSymbols.count(Name))
-          NewSymbols.insert(Name);
-      }
-
-      if (NewSymbols.empty())
-        break;
-
-      auto NewResolverResults = Resolver.lookup(NewSymbols);
-      if (!NewResolverResults)
-        return NewResolverResults.takeError();
-
-      for (auto &RRKV : *NewResolverResults) {
-        assert(!ResolvedSymbols.count(RRKV.first) && "Redundant resolution?");
-        ExternalSymbolMap.insert(RRKV);
-        ResolvedSymbols.insert(RRKV.first);
-      }
-    }
-  }
-
   while (!ExternalSymbolRelocations.empty()) {
-
     StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin();
 
     StringRef Name = i->first();
@@ -1044,10 +1012,29 @@ Error RuntimeDyldImpl::resolveExternalSymbols() {
       JITSymbolFlags Flags;
       RTDyldSymbolTable::const_iterator Loc = GlobalSymbolTable.find(Name);
       if (Loc == GlobalSymbolTable.end()) {
-        auto RRI = ExternalSymbolMap.find(Name);
-        assert(RRI != ExternalSymbolMap.end() && "No result for symbol");
-        Addr = RRI->second.getAddress();
-        Flags = RRI->second.getFlags();
+        // This is an external symbol, try to get its address from the symbol
+        // resolver.
+        // First search for the symbol in this logical dylib.
+        if (auto Sym = Resolver.findSymbolInLogicalDylib(Name.data())) {
+          if (auto AddrOrErr = Sym.getAddress()) {
+            Addr = *AddrOrErr;
+            Flags = Sym.getFlags();
+          } else
+            return AddrOrErr.takeError();
+        } else if (auto Err = Sym.takeError())
+          return Err;
+
+        // If that fails, try searching for an external symbol.
+        if (!Addr) {
+          if (auto Sym = Resolver.findSymbol(Name.data())) {
+            if (auto AddrOrErr = Sym.getAddress()) {
+              Addr = *AddrOrErr;
+              Flags = Sym.getFlags();
+            } else
+              return AddrOrErr.takeError();
+          } else if (auto Err = Sym.takeError())
+            return Err;
+        }
         // The call to getSymbolAddress may have caused additional modules to
         // be loaded, which may have added new entries to the
         // ExternalSymbolRelocations map.  Consquently, we need to update our
@@ -1108,7 +1095,6 @@ uint64_t RuntimeDyld::LoadedObjectInfo::getSectionLoadAddress(
 
 void RuntimeDyld::MemoryManager::anchor() {}
 void JITSymbolResolver::anchor() {}
-void LegacyJITSymbolResolver::anchor() {}
 
 RuntimeDyld::RuntimeDyld(RuntimeDyld::MemoryManager &MemMgr,
                          JITSymbolResolver &Resolver)