Revert "Decouple dllexport/dllimport from linkage"

Revert this for now until I fix an issue in Clang with it.

This reverts commit r199204.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199207 91177308-0d34-0410-b5e6-96231b3b80d8

17 files changed, 93 insertions, 189 deletions

diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index d4d6f7cee14e..a5b2aa586e46 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -242,8 +242,8 @@ bool LLParser::ParseTopLevelEntities() {
 
     // The Global variable production with no name can have many different
     // optional leading prefixes, the production is:
-    // GlobalVar ::= OptionalLinkage OptionalVisibility OptionalDLLStorageClass
-    //               OptionalThreadLocal OptionalAddrSpace OptionalUnNammedAddr
+    // GlobalVar ::= OptionalLinkage OptionalVisibility OptionalThreadLocal
+    //               OptionalAddrSpace OptionalUnNammedAddr
     //               ('constant'|'global') ...
     case lltok::kw_private:             // OptionalLinkage
     case lltok::kw_linker_private:      // OptionalLinkage
@@ -254,24 +254,24 @@ bool LLParser::ParseTopLevelEntities() {
     case lltok::kw_linkonce:            // OptionalLinkage
     case lltok::kw_linkonce_odr:        // OptionalLinkage
     case lltok::kw_appending:           // OptionalLinkage
+    case lltok::kw_dllexport:           // OptionalLinkage
     case lltok::kw_common:              // OptionalLinkage
+    case lltok::kw_dllimport:           // OptionalLinkage
     case lltok::kw_extern_weak:         // OptionalLinkage
     case lltok::kw_external: {          // OptionalLinkage
-      unsigned Linkage, Visibility, DLLStorageClass;
+      unsigned Linkage, Visibility;
       if (ParseOptionalLinkage(Linkage) ||
           ParseOptionalVisibility(Visibility) ||
-          ParseOptionalDLLStorageClass(DLLStorageClass) ||
-          ParseGlobal("", SMLoc(), Linkage, true, Visibility, DLLStorageClass))
+          ParseGlobal("", SMLoc(), Linkage, true, Visibility))
         return true;
       break;
     }
     case lltok::kw_default:       // OptionalVisibility
     case lltok::kw_hidden:        // OptionalVisibility
     case lltok::kw_protected: {   // OptionalVisibility
-      unsigned Visibility, DLLStorageClass;
+      unsigned Visibility;
       if (ParseOptionalVisibility(Visibility) ||
-          ParseOptionalDLLStorageClass(DLLStorageClass) ||
-          ParseGlobal("", SMLoc(), 0, false, Visibility, DLLStorageClass))
+          ParseGlobal("", SMLoc(), 0, false, Visibility))
         return true;
       break;
     }
@@ -280,7 +280,7 @@ bool LLParser::ParseTopLevelEntities() {
     case lltok::kw_addrspace:     // OptionalAddrSpace
     case lltok::kw_constant:      // GlobalType
     case lltok::kw_global:        // GlobalType
-      if (ParseGlobal("", SMLoc(), 0, false, 0, 0)) return true;
+      if (ParseGlobal("", SMLoc(), 0, false, 0)) return true;
       break;
 
     case lltok::kw_attributes: if (ParseUnnamedAttrGrp()) return true; break;
@@ -446,11 +446,9 @@ bool LLParser::ParseGlobalType(bool &IsConstant) {
 
 /// ParseUnnamedGlobal:
 ///   OptionalVisibility ALIAS ...
-///   OptionalLinkage OptionalVisibility OptionalDLLStorageClass
-///                                                     ...   -> global variable
+///   OptionalLinkage OptionalVisibility ...   -> global variable
 ///   GlobalID '=' OptionalVisibility ALIAS ...
-///   GlobalID '=' OptionalLinkage OptionalVisibility OptionalDLLStorageClass
-///                                                     ...   -> global variable
+///   GlobalID '=' OptionalLinkage OptionalVisibility ...   -> global variable
 bool LLParser::ParseUnnamedGlobal() {
   unsigned VarID = NumberedVals.size();
   std::string Name;
@@ -468,22 +466,19 @@ bool LLParser::ParseUnnamedGlobal() {
   }
 
   bool HasLinkage;
-  unsigned Linkage, Visibility, DLLStorageClass;
+  unsigned Linkage, Visibility;
   if (ParseOptionalLinkage(Linkage, HasLinkage) ||
-      ParseOptionalVisibility(Visibility) ||
-      ParseOptionalDLLStorageClass(DLLStorageClass))
+      ParseOptionalVisibility(Visibility))
     return true;
 
   if (HasLinkage || Lex.getKind() != lltok::kw_alias)
-    return ParseGlobal(Name, NameLoc, Linkage, HasLinkage, Visibility,
-                       DLLStorageClass);
-  return ParseAlias(Name, NameLoc, Visibility, DLLStorageClass);
+    return ParseGlobal(Name, NameLoc, Linkage, HasLinkage, Visibility);
+  return ParseAlias(Name, NameLoc, Visibility);
 }
 
 /// ParseNamedGlobal:
 ///   GlobalVar '=' OptionalVisibility ALIAS ...
-///   GlobalVar '=' OptionalLinkage OptionalVisibility OptionalDLLStorageClass
-///                                                     ...   -> global variable
+///   GlobalVar '=' OptionalLinkage OptionalVisibility ...   -> global variable
 bool LLParser::ParseNamedGlobal() {
   assert(Lex.getKind() == lltok::GlobalVar);
   LocTy NameLoc = Lex.getLoc();
@@ -491,17 +486,15 @@ bool LLParser::ParseNamedGlobal() {
   Lex.Lex();
 
   bool HasLinkage;
-  unsigned Linkage, Visibility, DLLStorageClass;
+  unsigned Linkage, Visibility;
   if (ParseToken(lltok::equal, "expected '=' in global variable") ||
       ParseOptionalLinkage(Linkage, HasLinkage) ||
-      ParseOptionalVisibility(Visibility) ||
-      ParseOptionalDLLStorageClass(DLLStorageClass))
+      ParseOptionalVisibility(Visibility))
     return true;
 
   if (HasLinkage || Lex.getKind() != lltok::kw_alias)
-    return ParseGlobal(Name, NameLoc, Linkage, HasLinkage, Visibility,
-                       DLLStorageClass);
-  return ParseAlias(Name, NameLoc, Visibility, DLLStorageClass);
+    return ParseGlobal(Name, NameLoc, Linkage, HasLinkage, Visibility);
+  return ParseAlias(Name, NameLoc, Visibility);
 }
 
 // MDString:
@@ -622,17 +615,16 @@ bool LLParser::ParseStandaloneMetadata() {
 }
 
 /// ParseAlias:
-///   ::= GlobalVar '=' OptionalVisibility OptionalDLLStorageClass 'alias'
-///                     OptionalLinkage Aliasee
+///   ::= GlobalVar '=' OptionalVisibility 'alias' OptionalLinkage Aliasee
 /// Aliasee
 ///   ::= TypeAndValue
 ///   ::= 'bitcast' '(' TypeAndValue 'to' Type ')'
 ///   ::= 'getelementptr' 'inbounds'? '(' ... ')'
 ///
-/// Everything through DLL storage class has already been parsed.
+/// Everything through visibility has already been parsed.
 ///
 bool LLParser::ParseAlias(const std::string &Name, LocTy NameLoc,
-                          unsigned Visibility, unsigned DLLStorageClass) {
+                          unsigned Visibility) {
   assert(Lex.getKind() == lltok::kw_alias);
   Lex.Lex();
   LocTy LinkageLoc = Lex.getLoc();
@@ -667,7 +659,6 @@ bool LLParser::ParseAlias(const std::string &Name, LocTy NameLoc,
                                     (GlobalValue::LinkageTypes)Linkage, Name,
                                     Aliasee);
   GA->setVisibility((GlobalValue::VisibilityTypes)Visibility);
-  GA->setDLLStorageClass((GlobalValue::DLLStorageClassTypes)DLLStorageClass);
 
   // See if this value already exists in the symbol table.  If so, it is either
   // a redefinition or a definition of a forward reference.
@@ -700,18 +691,18 @@ bool LLParser::ParseAlias(const std::string &Name, LocTy NameLoc,
 }
 
 /// ParseGlobal
-///   ::= GlobalVar '=' OptionalLinkage OptionalVisibility OptionalDLLStorageClass
-///       OptionalThreadLocal OptionalAddrSpace OptionalUnNammedAddr
+///   ::= GlobalVar '=' OptionalLinkage OptionalVisibility OptionalThreadLocal
+///       OptionalAddrSpace OptionalUnNammedAddr
 ///       OptionalExternallyInitialized GlobalType Type Const
-///   ::= OptionalLinkage OptionalVisibility OptionalDLLStorageClass
-///       OptionalThreadLocal OptionalAddrSpace OptionalUnNammedAddr
+///   ::= OptionalLinkage OptionalVisibility OptionalThreadLocal
+///       OptionalAddrSpace OptionalUnNammedAddr
 ///       OptionalExternallyInitialized GlobalType Type Const
 ///
 /// Everything through visibility has been parsed already.
 ///
 bool LLParser::ParseGlobal(const std::string &Name, LocTy NameLoc,
                            unsigned Linkage, bool HasLinkage,
-                           unsigned Visibility, unsigned DLLStorageClass) {
+                           unsigned Visibility) {
   unsigned AddrSpace;
   bool IsConstant, UnnamedAddr, IsExternallyInitialized;
   GlobalVariable::ThreadLocalMode TLM;
@@ -734,7 +725,8 @@ bool LLParser::ParseGlobal(const std::string &Name, LocTy NameLoc,
   // If the linkage is specified and is external, then no initializer is
   // present.
   Constant *Init = 0;
-  if (!HasLinkage || (Linkage != GlobalValue::ExternalWeakLinkage &&
+  if (!HasLinkage || (Linkage != GlobalValue::DLLImportLinkage &&
+                      Linkage != GlobalValue::ExternalWeakLinkage &&
                       Linkage != GlobalValue::ExternalLinkage)) {
     if (ParseGlobalValue(Ty, Init))
       return true;
@@ -783,7 +775,6 @@ bool LLParser::ParseGlobal(const std::string &Name, LocTy NameLoc,
   GV->setConstant(IsConstant);
   GV->setLinkage((GlobalValue::LinkageTypes)Linkage);
   GV->setVisibility((GlobalValue::VisibilityTypes)Visibility);
-  GV->setDLLStorageClass((GlobalValue::DLLStorageClassTypes)DLLStorageClass);
   GV->setExternallyInitialized(IsExternallyInitialized);
   GV->setThreadLocalMode(TLM);
   GV->setUnnamedAddr(UnnamedAddr);
@@ -1286,7 +1277,9 @@ bool LLParser::ParseOptionalReturnAttrs(AttrBuilder &B) {
 ///   ::= 'linkonce_odr'
 ///   ::= 'available_externally'
 ///   ::= 'appending'
+///   ::= 'dllexport'
 ///   ::= 'common'
+///   ::= 'dllimport'
 ///   ::= 'extern_weak'
 ///   ::= 'external'
 bool LLParser::ParseOptionalLinkage(unsigned &Res, bool &HasLinkage) {
@@ -1307,7 +1300,9 @@ bool LLParser::ParseOptionalLinkage(unsigned &Res, bool &HasLinkage) {
     Res = GlobalValue::AvailableExternallyLinkage;
     break;
   case lltok::kw_appending:      Res = GlobalValue::AppendingLinkage;     break;
+  case lltok::kw_dllexport:      Res = GlobalValue::DLLExportLinkage;     break;
   case lltok::kw_common:         Res = GlobalValue::CommonLinkage;        break;
+  case lltok::kw_dllimport:      Res = GlobalValue::DLLImportLinkage;     break;
   case lltok::kw_extern_weak:    Res = GlobalValue::ExternalWeakLinkage;  break;
   case lltok::kw_external:       Res = GlobalValue::ExternalLinkage;      break;
   }
@@ -1333,21 +1328,6 @@ bool LLParser::ParseOptionalVisibility(unsigned &Res) {
   return false;
 }
 
-/// ParseOptionalDLLStorageClass
-///   ::= /*empty*/
-///   ::= 'dllimport'
-///   ::= 'dllexport'
-///
-bool LLParser::ParseOptionalDLLStorageClass(unsigned &Res) {
-  switch (Lex.getKind()) {
-  default:                  Res = GlobalValue::DefaultStorageClass; return false;
-  case lltok::kw_dllimport: Res = GlobalValue::DLLImportStorageClass; break;
-  case lltok::kw_dllexport: Res = GlobalValue::DLLExportStorageClass; break;
-  }
-  Lex.Lex();
-  return false;
-}
-
 /// ParseOptionalCallingConv
 ///   ::= /*empty*/
 ///   ::= 'ccc'
@@ -2954,14 +2934,12 @@ bool LLParser::ParseFunctionHeader(Function *&Fn, bool isDefine) {
   unsigned Linkage;
 
   unsigned Visibility;
-  unsigned DLLStorageClass;
   AttrBuilder RetAttrs;
   CallingConv::ID CC;
   Type *RetType = 0;
   LocTy RetTypeLoc = Lex.getLoc();
   if (ParseOptionalLinkage(Linkage) ||
       ParseOptionalVisibility(Visibility) ||
-      ParseOptionalDLLStorageClass(DLLStorageClass) ||
       ParseOptionalCallingConv(CC) ||
       ParseOptionalReturnAttrs(RetAttrs) ||
       ParseType(RetType, RetTypeLoc, true /*void allowed*/))
@@ -2971,6 +2949,7 @@ bool LLParser::ParseFunctionHeader(Function *&Fn, bool isDefine) {
   switch ((GlobalValue::LinkageTypes)Linkage) {
   case GlobalValue::ExternalLinkage:
     break; // always ok.
+  case GlobalValue::DLLImportLinkage:
   case GlobalValue::ExternalWeakLinkage:
     if (isDefine)
       return Error(LinkageLoc, "invalid linkage for function definition");
@@ -2984,6 +2963,7 @@ bool LLParser::ParseFunctionHeader(Function *&Fn, bool isDefine) {
   case GlobalValue::LinkOnceODRLinkage:
   case GlobalValue::WeakAnyLinkage:
   case GlobalValue::WeakODRLinkage:
+  case GlobalValue::DLLExportLinkage:
     if (!isDefine)
       return Error(LinkageLoc, "invalid linkage for function declaration");
     break;
@@ -3130,7 +3110,6 @@ bool LLParser::ParseFunctionHeader(Function *&Fn, bool isDefine) {
 
   Fn->setLinkage((GlobalValue::LinkageTypes)Linkage);
   Fn->setVisibility((GlobalValue::VisibilityTypes)Visibility);
-  Fn->setDLLStorageClass((GlobalValue::DLLStorageClassTypes)DLLStorageClass);
   Fn->setCallingConv(CC);
   Fn->setAttributes(PAL);
   Fn->setUnnamedAddr(UnnamedAddr);
diff --git a/lib/AsmParser/LLParser.h b/lib/AsmParser/LLParser.h
index c62979e6f29e..ded776c3989c 100644
--- a/lib/AsmParser/LLParser.h
+++ b/lib/AsmParser/LLParser.h
@@ -204,7 +204,6 @@ namespace llvm {
       bool HasLinkage; return ParseOptionalLinkage(Linkage, HasLinkage);
     }
     bool ParseOptionalVisibility(unsigned &Visibility);
-    bool ParseOptionalDLLStorageClass(unsigned &DLLStorageClass);
     bool ParseOptionalCallingConv(CallingConv::ID &CC);
     bool ParseOptionalAlignment(unsigned &Alignment);
     bool ParseScopeAndOrdering(bool isAtomic, SynchronizationScope &Scope,
@@ -235,10 +234,8 @@ namespace llvm {
     bool ParseUnnamedGlobal();
     bool ParseNamedGlobal();
     bool ParseGlobal(const std::string &Name, LocTy Loc, unsigned Linkage,
-                     bool HasLinkage, unsigned Visibility,
-                     unsigned DLLStorageClass);
-    bool ParseAlias(const std::string &Name, LocTy Loc, unsigned Visibility,
-                    unsigned DLLStorageClass);
+                     bool HasLinkage, unsigned Visibility);
+    bool ParseAlias(const std::string &Name, LocTy Loc, unsigned Visibility);
     bool ParseStandaloneMetadata();
     bool ParseNamedMetadata();
     bool ParseMDString(MDString *&Result);
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 81ed803ba049..39a0dfa50063 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -80,8 +80,8 @@ static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
   case 2:  return GlobalValue::AppendingLinkage;
   case 3:  return GlobalValue::InternalLinkage;
   case 4:  return GlobalValue::LinkOnceAnyLinkage;
-  case 5:  return GlobalValue::ExternalLinkage; // Obsolete DLLImportLinkage
-  case 6:  return GlobalValue::ExternalLinkage; // Obsolete DLLExportLinkage
+  case 5:  return GlobalValue::DLLImportLinkage;
+  case 6:  return GlobalValue::DLLExportLinkage;
   case 7:  return GlobalValue::ExternalWeakLinkage;
   case 8:  return GlobalValue::CommonLinkage;
   case 9:  return GlobalValue::PrivateLinkage;
@@ -102,16 +102,6 @@ static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
   }
 }
 
-static GlobalValue::DLLStorageClassTypes
-GetDecodedDLLStorageClass(unsigned Val) {
-  switch (Val) {
-  default: // Map unknown values to default.
-  case 0: return GlobalValue::DefaultStorageClass;
-  case 1: return GlobalValue::DLLImportStorageClass;
-  case 2: return GlobalValue::DLLExportStorageClass;
-  }
-}
-
 static GlobalVariable::ThreadLocalMode GetDecodedThreadLocalMode(unsigned Val) {
   switch (Val) {
     case 0: return GlobalVariable::NotThreadLocal;
@@ -203,13 +193,6 @@ static SynchronizationScope GetDecodedSynchScope(unsigned Val) {
   }
 }
 
-static void UpgradeDLLImportExportLinkage(llvm::GlobalValue *GV, unsigned Val) {
-  switch (Val) {
-  case 5: GV->setDLLStorageClass(GlobalValue::DLLImportStorageClass); break;
-  case 6: GV->setDLLStorageClass(GlobalValue::DLLExportStorageClass); break;
-  }
-}
-
 namespace llvm {
 namespace {
   /// @brief A class for maintaining the slot number definition
@@ -1814,7 +1797,7 @@ error_code BitcodeReader::ParseModule(bool Resume) {
     }
     // GLOBALVAR: [pointer type, isconst, initid,
     //             linkage, alignment, section, visibility, threadlocal,
-    //             unnamed_addr, dllstorageclass]
+    //             unnamed_addr]
     case bitc::MODULE_CODE_GLOBALVAR: {
       if (Record.size() < 6)
         return Error(InvalidRecord);
@@ -1860,11 +1843,6 @@ error_code BitcodeReader::ParseModule(bool Resume) {
       NewGV->setVisibility(Visibility);
       NewGV->setUnnamedAddr(UnnamedAddr);
 
-      if (Record.size() > 10)
-        NewGV->setDLLStorageClass(GetDecodedDLLStorageClass(Record[10]));
-      else
-        UpgradeDLLImportExportLinkage(NewGV, Record[3]);
-
       ValueList.push_back(NewGV);
 
       // Remember which value to use for the global initializer.
@@ -1873,8 +1851,7 @@ error_code BitcodeReader::ParseModule(bool Resume) {
       break;
     }
     // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
-    //             alignment, section, visibility, gc, unnamed_addr,
-    //             dllstorageclass]
+    //             alignment, section, visibility, gc, unnamed_addr]
     case bitc::MODULE_CODE_FUNCTION: {
       if (Record.size() < 8)
         return Error(InvalidRecord);
@@ -1914,12 +1891,6 @@ error_code BitcodeReader::ParseModule(bool Resume) {
       Func->setUnnamedAddr(UnnamedAddr);
       if (Record.size() > 10 && Record[10] != 0)
         FunctionPrefixes.push_back(std::make_pair(Func, Record[10]-1));
-
-      if (Record.size() > 11)
-        Func->setDLLStorageClass(GetDecodedDLLStorageClass(Record[11]));
-      else
-        UpgradeDLLImportExportLinkage(Func, Record[3]);
-
       ValueList.push_back(Func);
 
       // If this is a function with a body, remember the prototype we are
@@ -1931,7 +1902,7 @@ error_code BitcodeReader::ParseModule(bool Resume) {
       break;
     }
     // ALIAS: [alias type, aliasee val#, linkage]
-    // ALIAS: [alias type, aliasee val#, linkage, visibility, dllstorageclass]
+    // ALIAS: [alias type, aliasee val#, linkage, visibility]
     case bitc::MODULE_CODE_ALIAS: {
       if (Record.size() < 3)
         return Error(InvalidRecord);
@@ -1946,10 +1917,6 @@ error_code BitcodeReader::ParseModule(bool Resume) {
       // Old bitcode files didn't have visibility field.
       if (Record.size() > 3)
         NewGA->setVisibility(GetDecodedVisibility(Record[3]));
-      if (Record.size() > 4)
-        NewGA->setDLLStorageClass(GetDecodedDLLStorageClass(Record[4]));
-      else
-        UpgradeDLLImportExportLinkage(NewGA, Record[2]);
       ValueList.push_back(NewGA);
       AliasInits.push_back(std::make_pair(NewGA, Record[1]));
       break;
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 1d763d66ddc4..be19b781d4aa 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -481,6 +481,8 @@ static unsigned getEncodedLinkage(const GlobalValue *GV) {
   case GlobalValue::AppendingLinkage:                return 2;
   case GlobalValue::InternalLinkage:                 return 3;
   case GlobalValue::LinkOnceAnyLinkage:              return 4;
+  case GlobalValue::DLLImportLinkage:                return 5;
+  case GlobalValue::DLLExportLinkage:                return 6;
   case GlobalValue::ExternalWeakLinkage:             return 7;
   case GlobalValue::CommonLinkage:                   return 8;
   case GlobalValue::PrivateLinkage:                  return 9;
@@ -502,15 +504,6 @@ static unsigned getEncodedVisibility(const GlobalValue *GV) {
   llvm_unreachable("Invalid visibility");
 }
 
-static unsigned getEncodedDLLStorageClass(const GlobalValue *GV) {
-  switch (GV->getDLLStorageClass()) {
-  case GlobalValue::DefaultStorageClass:   return 0;
-  case GlobalValue::DLLImportStorageClass: return 1;
-  case GlobalValue::DLLExportStorageClass: return 2;
-  }
-  llvm_unreachable("Invalid DLL storage class");
-}
-
 static unsigned getEncodedThreadLocalMode(const GlobalVariable *GV) {
   switch (GV->getThreadLocalMode()) {
     case GlobalVariable::NotThreadLocal:         return 0;
@@ -614,7 +607,7 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 
     // GLOBALVAR: [type, isconst, initid,
     //             linkage, alignment, section, visibility, threadlocal,
-    //             unnamed_addr, externally_initialized, dllstorageclass]
+    //             unnamed_addr, externally_initialized]
     Vals.push_back(VE.getTypeID(GV->getType()));
     Vals.push_back(GV->isConstant());
     Vals.push_back(GV->isDeclaration() ? 0 :
@@ -624,13 +617,11 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
     Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
     if (GV->isThreadLocal() ||
         GV->getVisibility() != GlobalValue::DefaultVisibility ||
-        GV->hasUnnamedAddr() || GV->isExternallyInitialized() ||
-        GV->getDLLStorageClass() != GlobalValue::DefaultStorageClass) {
+        GV->hasUnnamedAddr() || GV->isExternallyInitialized()) {
       Vals.push_back(getEncodedVisibility(GV));
       Vals.push_back(getEncodedThreadLocalMode(GV));
       Vals.push_back(GV->hasUnnamedAddr());
       Vals.push_back(GV->isExternallyInitialized());
-      Vals.push_back(getEncodedDLLStorageClass(GV));
     } else {
       AbbrevToUse = SimpleGVarAbbrev;
     }
@@ -655,7 +646,6 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
     Vals.push_back(F->hasUnnamedAddr());
     Vals.push_back(F->hasPrefixData() ? (VE.getValueID(F->getPrefixData()) + 1)
                                       : 0);
-    Vals.push_back(getEncodedDLLStorageClass(F));
 
     unsigned AbbrevToUse = 0;
     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
@@ -670,7 +660,6 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
     Vals.push_back(VE.getValueID(AI->getAliasee()));
     Vals.push_back(getEncodedLinkage(AI));
     Vals.push_back(getEncodedVisibility(AI));
-    Vals.push_back(getEncodedDLLStorageClass(AI));
     unsigned AbbrevToUse = 0;
     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
     Vals.clear();
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index cf950f8cc75e..5a8e8cc2f02f 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -257,6 +257,7 @@ void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
       OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
     }
     return;
+  case GlobalValue::DLLExportLinkage:
   case GlobalValue::AppendingLinkage:
     // FIXME: appending linkage variables should go into a section of
     // their name or something.  For now, just emit them as external.
@@ -271,6 +272,7 @@ void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
     return;
   case GlobalValue::AvailableExternallyLinkage:
     llvm_unreachable("Should never emit this");
+  case GlobalValue::DLLImportLinkage:
   case GlobalValue::ExternalWeakLinkage:
     llvm_unreachable("Don't know how to emit these");
   }
diff --git a/lib/ExecutionEngine/ExecutionEngine.cpp b/lib/ExecutionEngine/ExecutionEngine.cpp
index 88ec5b3e6a99..abc8877ec590 100644
--- a/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -1211,7 +1211,9 @@ void ExecutionEngine::emitGlobals() {
         }
 
         // If the existing global is strong, never replace it.
-        if (GVEntry->hasExternalLinkage())
+        if (GVEntry->hasExternalLinkage() ||
+            GVEntry->hasDLLImportLinkage() ||
+            GVEntry->hasDLLExportLinkage())
           continue;
 
         // Otherwise, we know it's linkonce/weak, replace it if this is a strong
diff --git a/lib/IR/AsmWriter.cpp b/lib/IR/AsmWriter.cpp
index eba05c5f28e1..91684c9c70ef 100644
--- a/lib/IR/AsmWriter.cpp
+++ b/lib/IR/AsmWriter.cpp
@@ -1367,6 +1367,8 @@ static void PrintLinkage(GlobalValue::LinkageTypes LT,
   case GlobalValue::WeakODRLinkage:       Out << "weak_odr ";       break;
   case GlobalValue::CommonLinkage:        Out << "common ";         break;
   case GlobalValue::AppendingLinkage:     Out << "appending ";      break;
+  case GlobalValue::DLLImportLinkage:     Out << "dllimport ";      break;
+  case GlobalValue::DLLExportLinkage:     Out << "dllexport ";      break;
   case GlobalValue::ExternalWeakLinkage:  Out << "extern_weak ";    break;
   case GlobalValue::AvailableExternallyLinkage:
     Out << "available_externally ";
@@ -1384,15 +1386,6 @@ static void PrintVisibility(GlobalValue::VisibilityTypes Vis,
   }
 }
 
-static void PrintDLLStorageClass(GlobalValue::DLLStorageClassTypes SCT,
-                                 formatted_raw_ostream &Out) {
-  switch (SCT) {
-  case GlobalValue::DefaultStorageClass: break;
-  case GlobalValue::DLLImportStorageClass: Out << "dllimport "; break;
-  case GlobalValue::DLLExportStorageClass: Out << "dllexport "; break;
-  }
-}
-
 static void PrintThreadLocalModel(GlobalVariable::ThreadLocalMode TLM,
                                   formatted_raw_ostream &Out) {
   switch (TLM) {
@@ -1425,7 +1418,6 @@ void AssemblyWriter::printGlobal(const GlobalVariable *GV) {
 
   PrintLinkage(GV->getLinkage(), Out);
   PrintVisibility(GV->getVisibility(), Out);
-  PrintDLLStorageClass(GV->getDLLStorageClass(), Out);
   PrintThreadLocalModel(GV->getThreadLocalMode(), Out);
 
   if (unsigned AddressSpace = GV->getType()->getAddressSpace())
@@ -1463,7 +1455,6 @@ void AssemblyWriter::printAlias(const GlobalAlias *GA) {
     Out << " = ";
   }
   PrintVisibility(GA->getVisibility(), Out);
-  PrintDLLStorageClass(GA->getDLLStorageClass(), Out);
 
   Out << "alias ";
 
@@ -1561,7 +1552,6 @@ void AssemblyWriter::printFunction(const Function *F) {
 
   PrintLinkage(F->getLinkage(), Out);
   PrintVisibility(F->getVisibility(), Out);
-  PrintDLLStorageClass(F->getDLLStorageClass(), Out);
 
   // Print the calling convention.
   if (F->getCallingConv() != CallingConv::C) {
diff --git a/lib/IR/Core.cpp b/lib/IR/Core.cpp
index 6e920a2daa4b..ff4976bcbf98 100644
--- a/lib/IR/Core.cpp
+++ b/lib/IR/Core.cpp
@@ -1164,6 +1164,10 @@ LLVMLinkage LLVMGetLinkage(LLVMValueRef Global) {
     return LLVMLinkerPrivateLinkage;
   case GlobalValue::LinkerPrivateWeakLinkage:
     return LLVMLinkerPrivateWeakLinkage;
+  case GlobalValue::DLLImportLinkage:
+    return LLVMDLLImportLinkage;
+  case GlobalValue::DLLExportLinkage:
+    return LLVMDLLExportLinkage;
   case GlobalValue::ExternalWeakLinkage:
     return LLVMExternalWeakLinkage;
   case GlobalValue::CommonLinkage:
@@ -1215,12 +1219,10 @@ void LLVMSetLinkage(LLVMValueRef Global, LLVMLinkage Linkage) {
     GV->setLinkage(GlobalValue::LinkerPrivateWeakLinkage);
     break;
   case LLVMDLLImportLinkage:
-    DEBUG(errs()
-          << "LLVMSetLinkage(): LLVMDLLImportLinkage is no longer supported.");
+    GV->setLinkage(GlobalValue::DLLImportLinkage);
     break;
   case LLVMDLLExportLinkage:
-    DEBUG(errs()
-          << "LLVMSetLinkage(): LLVMDLLExportLinkage is no longer supported.");
+    GV->setLinkage(GlobalValue::DLLExportLinkage);
     break;
   case LLVMExternalWeakLinkage:
     GV->setLinkage(GlobalValue::ExternalWeakLinkage);
diff --git a/lib/IR/Verifier.cpp b/lib/IR/Verifier.cpp
index d8e5c89598e2..9e150e857561 100644
--- a/lib/IR/Verifier.cpp
+++ b/lib/IR/Verifier.cpp
@@ -421,12 +421,16 @@ void Verifier::visitGlobalValue(GlobalValue &GV) {
   Assert1(!GV.isDeclaration() ||
           GV.isMaterializable() ||
           GV.hasExternalLinkage() ||
+          GV.hasDLLImportLinkage() ||
           GV.hasExternalWeakLinkage() ||
           (isa<GlobalAlias>(GV) &&
            (GV.hasLocalLinkage() || GV.hasWeakLinkage())),
-          "Global is external, but doesn't have external or weak linkage!",
+  "Global is external, but doesn't have external or dllimport or weak linkage!",
           &GV);
 
+  Assert1(!GV.hasDLLImportLinkage() || GV.isDeclaration(),
+          "Global is marked as dllimport, but not external", &GV);
+
   Assert1(!GV.hasAppendingLinkage() || isa<GlobalVariable>(GV),
           "Only global variables can have appending linkage!", &GV);
 
@@ -452,7 +456,8 @@ void Verifier::visitGlobalVariable(GlobalVariable &GV) {
               &GV);
     }
   } else {
-    Assert1(GV.hasExternalLinkage() || GV.hasExternalWeakLinkage(),
+    Assert1(GV.hasExternalLinkage() || GV.hasDLLImportLinkage() ||
+            GV.hasExternalWeakLinkage(),
             "invalid linkage type for global declaration", &GV);
   }
 
@@ -497,11 +502,6 @@ void Verifier::visitGlobalVariable(GlobalVariable &GV) {
     }
   }
 
-  Assert1(!GV.hasDLLImportStorageClass() ||
-          (GV.isDeclaration() && GV.hasExternalLinkage()) ||
-          GV.hasAvailableExternallyLinkage(),
-          "Global is marked as dllimport, but not external", &GV);
-
   if (!GV.hasInitializer()) {
     visitGlobalValue(GV);
     return;
@@ -1078,7 +1078,8 @@ void Verifier::visitFunction(Function &F) {
   if (F.isMaterializable()) {
     // Function has a body somewhere we can't see.
   } else if (F.isDeclaration()) {
-    Assert1(F.hasExternalLinkage() || F.hasExternalWeakLinkage(),
+    Assert1(F.hasExternalLinkage() || F.hasDLLImportLinkage() ||
+            F.hasExternalWeakLinkage(),
             "invalid linkage type for function declaration", &F);
   } else {
     // Verify that this function (which has a body) is not named "llvm.*".  It
@@ -1104,11 +1105,6 @@ void Verifier::visitFunction(Function &F) {
     if (F.hasAddressTaken(&U))
       Assert1(0, "Invalid user of intrinsic instruction!", U);
   }
-
-  Assert1(!F.hasDLLImportStorageClass() ||
-          (F.isDeclaration() && F.hasExternalLinkage()) ||
-          F.hasAvailableExternallyLinkage(),
-          "Function is marked as dllimport, but not external.", &F);
 }
 
 // verifyBasicBlock - Verify that a basic block is well formed...
diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index 4d039eb2c6da..8f2200e4ea2e 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -543,8 +543,8 @@ bool ModuleLinker::getLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
   if (SrcIsDeclaration) {
     // If Src is external or if both Src & Dest are external..  Just link the
     // external globals, we aren't adding anything.
-    if (Src->hasDLLImportStorageClass()) {
-      // If one of GVs is marked as DLLImport, result should be dllimport'ed.
+    if (Src->hasDLLImportLinkage()) {
+      // If one of GVs has DLLImport linkage, result should be dllimport'ed.
       if (DestIsDeclaration) {
         LinkFromSrc = true;
         LT = Src->getLinkage();
@@ -557,7 +557,7 @@ bool ModuleLinker::getLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
       LinkFromSrc = false;
       LT = Dest->getLinkage();
     }
-  } else if (DestIsDeclaration && !Dest->hasDLLImportStorageClass()) {
+  } else if (DestIsDeclaration && !Dest->hasDLLImportLinkage()) {
     // If Dest is external but Src is not:
     LinkFromSrc = true;
     LT = Src->getLinkage();
@@ -584,8 +584,10 @@ bool ModuleLinker::getLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
       LT = GlobalValue::ExternalLinkage;
     }
   } else {
-    assert((Dest->hasExternalLinkage()  || Dest->hasExternalWeakLinkage()) &&
-           (Src->hasExternalLinkage()   || Src->hasExternalWeakLinkage()) &&
+    assert((Dest->hasExternalLinkage()  || Dest->hasDLLImportLinkage() ||
+            Dest->hasDLLExportLinkage() || Dest->hasExternalWeakLinkage()) &&
+           (Src->hasExternalLinkage()   || Src->hasDLLImportLinkage() ||
+            Src->hasDLLExportLinkage()  || Src->hasExternalWeakLinkage()) &&
            "Unexpected linkage type!");
     return emitError("Linking globals named '" + Src->getName() +
                  "': symbol multiply defined!");
diff --git a/lib/Target/CppBackend/CPPBackend.cpp b/lib/Target/CppBackend/CPPBackend.cpp
index b13709914bf6..6e2dd0a8e7b2 100644
--- a/lib/Target/CppBackend/CPPBackend.cpp
+++ b/lib/Target/CppBackend/CPPBackend.cpp
@@ -131,7 +131,6 @@ namespace {
   private:
     void printLinkageType(GlobalValue::LinkageTypes LT);
     void printVisibilityType(GlobalValue::VisibilityTypes VisTypes);
-    void printDLLStorageClassType(GlobalValue::DLLStorageClassTypes DSCType);
     void printThreadLocalMode(GlobalVariable::ThreadLocalMode TLM);
     void printCallingConv(CallingConv::ID cc);
     void printEscapedString(const std::string& str);
@@ -301,6 +300,10 @@ void CppWriter::printLinkageType(GlobalValue::LinkageTypes LT) {
     Out << "GlobalValue::AppendingLinkage"; break;
   case GlobalValue::ExternalLinkage:
     Out << "GlobalValue::ExternalLinkage"; break;
+  case GlobalValue::DLLImportLinkage:
+    Out << "GlobalValue::DLLImportLinkage"; break;
+  case GlobalValue::DLLExportLinkage:
+    Out << "GlobalValue::DLLExportLinkage"; break;
   case GlobalValue::ExternalWeakLinkage:
     Out << "GlobalValue::ExternalWeakLinkage"; break;
   case GlobalValue::CommonLinkage:
@@ -322,21 +325,6 @@ void CppWriter::printVisibilityType(GlobalValue::VisibilityTypes VisType) {
   }
 }
 
-void CppWriter::printDLLStorageClassType(
-                                    GlobalValue::DLLStorageClassTypes DSCType) {
-  switch (DSCType) {
-  case GlobalValue::DefaultStorageClass:
-    Out << "GlobalValue::DefaultStorageClass";
-    break;
-  case GlobalValue::DLLImportStorageClass:
-    Out << "GlobalValue::DLLImportStorageClass";
-    break;
-  case GlobalValue::DLLExportStorageClass:
-    Out << "GlobalValue::DLLExportStorageClass";
-    break;
-  }
-}
-
 void CppWriter::printThreadLocalMode(GlobalVariable::ThreadLocalMode TLM) {
   switch (TLM) {
     case GlobalVariable::NotThreadLocal:
@@ -1040,13 +1028,6 @@ void CppWriter::printVariableHead(const GlobalVariable *GV) {
     Out << ");";
     nl(Out);
   }
-  if (GV->getDLLStorageClass() != GlobalValue::DefaultStorageClass) {
-    printCppName(GV);
-    Out << "->setDLLStorageClass(";
-    printDLLStorageClassType(GV->getDLLStorageClass());
-    Out << ");";
-    nl(Out);
-  }
   if (GV->isThreadLocal()) {
     printCppName(GV);
     Out << "->setThreadLocalMode(";
@@ -1765,13 +1746,6 @@ void CppWriter::printFunctionHead(const Function* F) {
     Out << ");";
     nl(Out);
   }
-  if (F->getDLLStorageClass() != GlobalValue::DefaultStorageClass) {
-    printCppName(F);
-    Out << "->setDLLStorageClass(";
-    printDLLStorageClassType(F->getDLLStorageClass());
-    Out << ");";
-    nl(Out);
-  }
   if (F->hasGC()) {
     printCppName(F);
     Out << "->setGC(\"" << F->getGC() << "\");";
diff --git a/lib/Target/X86/X86AsmPrinter.cpp b/lib/Target/X86/X86AsmPrinter.cpp
index ad7d3e0fdcae..a2c3f770d310 100644
--- a/lib/Target/X86/X86AsmPrinter.cpp
+++ b/lib/Target/X86/X86AsmPrinter.cpp
@@ -649,20 +649,20 @@ void X86AsmPrinter::EmitEndOfAsmFile(Module &M) {
     // Necessary for dllexport support
     std::vector<const MCSymbol*> DLLExportedFns, DLLExportedGlobals;
 
+    const TargetLoweringObjectFileCOFF &TLOFCOFF =
+      static_cast<const TargetLoweringObjectFileCOFF&>(getObjFileLowering());
+
     for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I)
-      if (I->hasDLLExportStorageClass())
+      if (I->hasDLLExportLinkage())
         DLLExportedFns.push_back(getSymbol(I));
 
     for (Module::const_global_iterator I = M.global_begin(),
            E = M.global_end(); I != E; ++I)
-      if (I->hasDLLExportStorageClass())
+      if (I->hasDLLExportLinkage())
         DLLExportedGlobals.push_back(getSymbol(I));
 
     // Output linker support code for dllexported globals on windows.
     if (!DLLExportedGlobals.empty() || !DLLExportedFns.empty()) {
-      const TargetLoweringObjectFileCOFF &TLOFCOFF =
-        static_cast<const TargetLoweringObjectFileCOFF&>(getObjFileLowering());
-
       OutStreamer.SwitchSection(TLOFCOFF.getDrectveSection());
       SmallString<128> name;
       for (unsigned i = 0, e = DLLExportedGlobals.size(); i != e; ++i) {
diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index 7b2d1d7776fb..fd10a4a09eab 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -697,7 +697,7 @@ bool X86FastISel::X86SelectCallAddress(const Value *V, X86AddressMode &AM) {
       return false;
 
     // Can't handle DLLImport.
-    if (GV->hasDLLImportStorageClass())
+    if (GV->hasDLLImportLinkage())
       return false;
 
     // Can't handle TLS.
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index ccc96f4a0b81..a41faab73b4b 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2796,7 +2796,7 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
     // We should use extra load for direct calls to dllimported functions in
     // non-JIT mode.
     const GlobalValue *GV = G->getGlobal();
-    if (!GV->hasDLLImportStorageClass()) {
+    if (!GV->hasDLLImportLinkage()) {
       unsigned char OpFlags = 0;
       bool ExtraLoad = false;
       unsigned WrapperKind = ISD::DELETED_NODE;
diff --git a/lib/Target/X86/X86Subtarget.cpp b/lib/Target/X86/X86Subtarget.cpp
index 6f724b42d977..b183ed0314f2 100644
--- a/lib/Target/X86/X86Subtarget.cpp
+++ b/lib/Target/X86/X86Subtarget.cpp
@@ -55,7 +55,7 @@ unsigned char X86Subtarget::
 ClassifyGlobalReference(const GlobalValue *GV, const TargetMachine &TM) const {
   // DLLImport only exists on windows, it is implemented as a load from a
   // DLLIMPORT stub.
-  if (GV->hasDLLImportStorageClass())
+  if (GV->hasDLLImportLinkage())
     return X86II::MO_DLLIMPORT;
 
   // Determine whether this is a reference to a definition or a declaration.
diff --git a/lib/Target/XCore/XCoreAsmPrinter.cpp b/lib/Target/XCore/XCoreAsmPrinter.cpp
index 778bf9ca39dc..ee84aa4a8829 100644
--- a/lib/Target/XCore/XCoreAsmPrinter.cpp
+++ b/lib/Target/XCore/XCoreAsmPrinter.cpp
@@ -135,6 +135,10 @@ void XCoreAsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
   case GlobalValue::InternalLinkage:
   case GlobalValue::PrivateLinkage:
     break;
+  case GlobalValue::DLLImportLinkage:
+    llvm_unreachable("DLLImport linkage is not supported by this target!");
+  case GlobalValue::DLLExportLinkage:
+    llvm_unreachable("DLLExport linkage is not supported by this target!");
   default:
     llvm_unreachable("Unknown linkage type!");
   }
diff --git a/lib/Transforms/IPO/Internalize.cpp b/lib/Transforms/IPO/Internalize.cpp
index 030771417766..dae69ce09156 100644
--- a/lib/Transforms/IPO/Internalize.cpp
+++ b/lib/Transforms/IPO/Internalize.cpp
@@ -116,7 +116,7 @@ static bool shouldInternalize(const GlobalValue &GV,
     return false;
 
   // Assume that dllexported symbols are referenced elsewhere
-  if (GV.hasDLLExportStorageClass())
+  if (GV.hasDLLExportLinkage())
     return false;
 
   // Already has internal linkage