Introduce new linkage types linkonce_odr, weak_odr, common_odr

and extern_weak_odr.  These are the same as the non-odr versions,
except that they indicate that the global will only be overridden
by an *equivalent* global.  In C, a function with weak linkage can
be overridden by a function which behaves completely differently.
This means that IP passes have to skip weak functions, since any
deductions made from the function definition might be wrong, since
the definition could be replaced by something completely different
at link time.   This is not allowed in C++, thanks to the ODR
(One-Definition-Rule): if a function is replaced by another at
link-time, then the new function must be the same as the original
function.  If a language knows that a function or other global can
only be overridden by an equivalent global, it can give it the
weak_odr linkage type, and the optimizers will understand that it
is alright to make deductions based on the function body.  The
code generators on the other hand map weak and weak_odr linkage
to the same thing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66339 91177308-0d34-0410-b5e6-96231b3b80d8

43 files changed, 370 insertions, 192 deletions

diff --git a/docs/LangRef.html b/docs/LangRef.html
index 83ea026c6b..0985cbd61e 100644
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -545,11 +545,26 @@ All Global Variables and Functions have one of the following types of linkage:
   </dd>
 
   <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
+
   <dd>The semantics of this linkage follow the ELF object file model: the
     symbol is weak until linked, if not linked, the symbol becomes null instead
     of being an undefined reference.
   </dd>
 
+  <dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
+  <dt><tt><b><a name="linkage_common">common_odr</a></b></tt>: </dt>
+  <dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
+  <dt><tt><b><a name="linkage_externweak">extern_weak_odr</a></b></tt>: </dt>
+  <dd>Some languages allow inequivalent globals to be merged, such as two
+    functions with different semantics.  Other languages, such as <tt>C++</tt>,
+    ensure that only equivalent globals are ever merged (the "one definition
+    rule" - <tt>odr</tt>).  Such languages can use the <tt>linkonce_odr</tt>,
+    <tt>common_odr</tt>, <tt>weak_odr</tt> and <tt>extern_weak_odr</tt> linkage
+    types to indicate that the global will only be merged with equivalent
+    globals.  These linkage types are otherwise the same as their
+    non-<tt>odr</tt> versions.
+  </dd>
+
   <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
 
   <dd>If none of the above identifiers are used, the global is externally
@@ -592,9 +607,9 @@ external (i.e., lacking any linkage declarations), they are accessible
 outside of the current module.</p>
 <p>It is illegal for a function <i>declaration</i>
 to have any linkage type other than "externally visible", <tt>dllimport</tt>,
-or <tt>extern_weak</tt>.</p>
-<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
-linkages.</p>
+<tt>extern_weak</tt> or <tt>extern_weak_odr</tt>.</p>
+<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
+or <tt>weak_odr</tt> linkages.</p>
 </div>
 
 <!-- ======================================================================= -->
diff --git a/docs/ProgrammersManual.html b/docs/ProgrammersManual.html
index 289a569024..cf46a97e68 100644
--- a/docs/ProgrammersManual.html
+++ b/docs/ProgrammersManual.html
@@ -3322,11 +3322,12 @@ never change at runtime).</p>
     <p>Create a new global variable of the specified type. If
     <tt>isConstant</tt> is true then the global variable will be marked as
     unchanging for the program. The Linkage parameter specifies the type of
-    linkage (internal, external, weak, linkonce, appending) for the variable. If
-    the linkage is InternalLinkage, WeakLinkage, or LinkOnceLinkage,&nbsp; then
-    the resultant global variable will have internal linkage.  AppendingLinkage
-    concatenates together all instances (in different translation units) of the
-    variable into a single variable but is only applicable to arrays.  &nbsp;See
+    linkage (internal, external, weak, linkonce, appending) for the variable.
+    If the linkage is InternalLinkage, WeakAnyLinkage, WeakODRLinkage,
+    LinkOnceAnyLinkage or LinkOnceODRLinkage,&nbsp; then the resultant
+    global variable will have internal linkage.  AppendingLinkage concatenates
+    together all instances (in different translation units) of the variable
+    into a single variable but is only applicable to arrays.  &nbsp;See
     the <a href="LangRef.html#modulestructure">LLVM Language Reference</a> for
     further details on linkage types. Optionally an initializer, a name, and the
     module to put the variable into may be specified for the global variable as
diff --git a/include/llvm-c/Core.h b/include/llvm-c/Core.h
index 6016ac61b5..5d8cff414f 100644
--- a/include/llvm-c/Core.h
+++ b/include/llvm-c/Core.h
@@ -115,16 +115,26 @@ typedef enum {
 
 typedef enum {
   LLVMExternalLinkage,    /**< Externally visible function */
-  LLVMLinkOnceLinkage,    /**< Keep one copy of function when linking (inline)*/
-  LLVMWeakLinkage,        /**< Keep one copy of function when linking (weak) */
+  LLVMLinkOnceAnyLinkage, /**< Keep one copy of function when linking (inline)*/
+  LLVMLinkOnceODRLinkage, /**< Same, but only replaced by something
+                            equivalent. */
+  LLVMWeakAnyLinkage,     /**< Keep one copy of function when linking (weak) */
+  LLVMWeakODRLinkage,     /**< Same, but only replaced by something
+                            equivalent. */
   LLVMAppendingLinkage,   /**< Special purpose, only applies to global arrays */
   LLVMInternalLinkage,    /**< Rename collisions when linking (static
                                functions) */
+  LLVMPrivateLinkage,     /**< Like Internal, but omit from symbol table */
   LLVMDLLImportLinkage,   /**< Function to be imported from DLL */
   LLVMDLLExportLinkage,   /**< Function to be accessible from DLL */
-  LLVMExternalWeakLinkage,/**< ExternalWeak linkage description */
-  LLVMGhostLinkage        /**< Stand-in functions for streaming fns from
+  LLVMExternalWeakAnyLinkage,/**< ExternalWeak linkage description */
+  LLVMExternalWeakODRLinkage,/**< Same, but only replaced by something
+                               equivalent. */
+  LLVMGhostLinkage,       /**< Stand-in functions for streaming fns from
                                bitcode */
+  LLVMCommonAnyLinkage,   /**< Tentative definitions */
+  LLVMCommonODRLinkage    /**< Same, but only replaced by something
+                            equivalent. */
 } LLVMLinkage;
 
 typedef enum {
diff --git a/include/llvm/GlobalValue.h b/include/llvm/GlobalValue.h
index 8fb5580d0d..33f50c907b 100644
--- a/include/llvm/GlobalValue.h
+++ b/include/llvm/GlobalValue.h
@@ -31,16 +31,20 @@ public:
   /// @brief An enumeration for the kinds of linkage for global values.
   enum LinkageTypes {
     ExternalLinkage = 0,///< Externally visible function
-    LinkOnceLinkage,    ///< Keep one copy of function when linking (inline)
-    WeakLinkage,        ///< Keep one copy of named function when linking (weak)
+    LinkOnceAnyLinkage, ///< Keep one copy of function when linking (inline)
+    LinkOnceODRLinkage, ///< Same, but only replaced by something equivalent.
+    WeakAnyLinkage,     ///< Keep one copy of named function when linking (weak)
+    WeakODRLinkage,     ///< Same, but only replaced by something equivalent.
     AppendingLinkage,   ///< Special purpose, only applies to global arrays
     InternalLinkage,    ///< Rename collisions when linking (static functions)
     PrivateLinkage,     ///< Like Internal, but omit from symbol table
     DLLImportLinkage,   ///< Function to be imported from DLL
     DLLExportLinkage,   ///< Function to be accessible from DLL
-    ExternalWeakLinkage,///< ExternalWeak linkage description
+    ExternalWeakAnyLinkage,///< ExternalWeak linkage description
+    ExternalWeakODRLinkage,///< Same, but only replaced by something equivalent.
     GhostLinkage,       ///< Stand-in functions for streaming fns from BC files
-    CommonLinkage       ///< Tentative definitions
+    CommonAnyLinkage,   ///< Tentative definitions
+    CommonODRLinkage    ///< Same, but only replaced by something equivalent.
   };
 
   /// @brief An enumeration for the kinds of visibility of global values.
@@ -99,31 +103,67 @@ public:
     return reinterpret_cast<const PointerType*>(User::getType());
   }
 
-  bool hasExternalLinkage()   const { return Linkage == ExternalLinkage; }
-  bool hasLinkOnceLinkage()   const { return Linkage == LinkOnceLinkage; }
-  bool hasWeakLinkage()       const { return Linkage == WeakLinkage; }
-  bool hasCommonLinkage()     const { return Linkage == CommonLinkage; }
-  bool hasAppendingLinkage()  const { return Linkage == AppendingLinkage; }
-  bool hasInternalLinkage()   const { return Linkage == InternalLinkage; }
-  bool hasPrivateLinkage()    const { return Linkage == PrivateLinkage; }
-  bool hasLocalLinkage()      const {
+  static LinkageTypes getLinkOnceLinkage(bool ODR) {
+    return ODR ? LinkOnceODRLinkage : LinkOnceAnyLinkage;
+  }
+  static LinkageTypes getWeakLinkage(bool ODR) {
+    return ODR ? WeakODRLinkage : WeakAnyLinkage;
+  }
+  static LinkageTypes getCommonLinkage(bool ODR) {
+    return ODR ? CommonODRLinkage : CommonAnyLinkage;
+  }
+  static LinkageTypes getExternalWeakLinkage(bool ODR) {
+    return ODR ? ExternalWeakODRLinkage : ExternalWeakAnyLinkage;
+  }
+
+  bool hasExternalLinkage() const { return Linkage == ExternalLinkage; }
+  bool hasLinkOnceLinkage() const {
+    return Linkage == LinkOnceAnyLinkage || Linkage == LinkOnceODRLinkage;
+  }
+  bool hasWeakLinkage() const {
+    return Linkage == WeakAnyLinkage || Linkage == WeakODRLinkage;
+  }
+  bool hasAppendingLinkage() const { return Linkage == AppendingLinkage; }
+  bool hasInternalLinkage() const { return Linkage == InternalLinkage; }
+  bool hasPrivateLinkage() const { return Linkage == PrivateLinkage; }
+  bool hasLocalLinkage() const {
     return Linkage == InternalLinkage || Linkage == PrivateLinkage;
   }
-  bool hasDLLImportLinkage()  const { return Linkage == DLLImportLinkage; }
-  bool hasDLLExportLinkage()  const { return Linkage == DLLExportLinkage; }
-  bool hasExternalWeakLinkage() const { return Linkage == ExternalWeakLinkage; }
-  bool hasGhostLinkage()      const { return Linkage == GhostLinkage; }
+  bool hasDLLImportLinkage() const { return Linkage == DLLImportLinkage; }
+  bool hasDLLExportLinkage() const { return Linkage == DLLExportLinkage; }
+  bool hasExternalWeakLinkage() const {
+    return Linkage == ExternalWeakAnyLinkage ||
+      Linkage == ExternalWeakODRLinkage;
+  }
+  bool hasGhostLinkage() const { return Linkage == GhostLinkage; }
+  bool hasCommonLinkage() const {
+    return Linkage == CommonAnyLinkage || Linkage == CommonODRLinkage;
+  }
+
   void setLinkage(LinkageTypes LT) { Linkage = LT; }
   LinkageTypes getLinkage() const { return Linkage; }
 
   /// mayBeOverridden - Whether the definition of this global may be replaced
-  /// at link time.  For example, if a function has weak linkage then the code
-  /// defining it may be replaced by different code.
+  /// by something non-equivalent at link time.  For example, if a function has
+  /// weak linkage then the code defining it may be replaced by different code.
   bool mayBeOverridden() const {
-    return (Linkage == WeakLinkage ||
-            Linkage == LinkOnceLinkage ||
-            Linkage == CommonLinkage ||
-            Linkage == ExternalWeakLinkage);
+    return (Linkage == WeakAnyLinkage ||
+            Linkage == LinkOnceAnyLinkage ||
+            Linkage == CommonAnyLinkage ||
+            Linkage == ExternalWeakAnyLinkage);
+  }
+
+  /// isWeakForLinker - Whether the definition of this global may be replaced at
+  /// link time, whether the replacement is equivalent to the original or not.
+  bool isWeakForLinker() const {
+    return (Linkage == WeakAnyLinkage ||
+            Linkage == WeakODRLinkage ||
+            Linkage == LinkOnceAnyLinkage ||
+            Linkage == LinkOnceODRLinkage ||
+            Linkage == CommonAnyLinkage ||
+            Linkage == CommonODRLinkage ||
+            Linkage == ExternalWeakAnyLinkage ||
+            Linkage == ExternalWeakODRLinkage);
   }
 
   /// copyAttributesFrom - copy all additional attributes (those not needed to
diff --git a/lib/Analysis/DebugInfo.cpp b/lib/Analysis/DebugInfo.cpp
index deb5c9bbfb..a063aa53ba 100644
--- a/lib/Analysis/DebugInfo.cpp
+++ b/lib/Analysis/DebugInfo.cpp
@@ -344,7 +344,7 @@ DIAnchor DIFactory::GetOrCreateAnchor(unsigned TAG, const char *Name) {
   if (GV->hasInitializer()) 
     return SubProgramAnchor = DIAnchor(GV);
   
-  GV->setLinkage(GlobalValue::LinkOnceLinkage);
+  GV->setLinkage(GlobalValue::LinkOnceAnyLinkage);
   GV->setSection("llvm.metadata");
   GV->setConstant(true);
   M.addTypeName("llvm.dbg.anchor.type", EltTy);
diff --git a/lib/AsmParser/LLLexer.cpp b/lib/AsmParser/LLLexer.cpp
index fb491d3278..6f1d5eefe8 100644
--- a/lib/AsmParser/LLLexer.cpp
+++ b/lib/AsmParser/LLLexer.cpp
@@ -456,15 +456,19 @@ lltok::Kind LLLexer::LexIdentifier() {
   KEYWORD(private);
   KEYWORD(internal);
   KEYWORD(linkonce);
+  KEYWORD(linkonce_odr);
   KEYWORD(weak);
+  KEYWORD(weak_odr);
   KEYWORD(appending);
   KEYWORD(dllimport);
   KEYWORD(dllexport);
   KEYWORD(common);
+  KEYWORD(common_odr);
   KEYWORD(default);
   KEYWORD(hidden);
   KEYWORD(protected);
   KEYWORD(extern_weak);
+  KEYWORD(extern_weak_odr);
   KEYWORD(external);
   KEYWORD(thread_local);
   KEYWORD(zeroinitializer);
diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 19f8415bba..90dd50743a 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -116,12 +116,16 @@ bool LLParser::ParseTopLevelEntities() {
     case lltok::kw_private:       // OptionalLinkage
     case lltok::kw_internal:      // OptionalLinkage
     case lltok::kw_weak:          // OptionalLinkage
+    case lltok::kw_weak_odr:      // OptionalLinkage
     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_common_odr:    // OptionalLinkage
     case lltok::kw_dllimport:     // OptionalLinkage
     case lltok::kw_extern_weak:   // OptionalLinkage
+    case lltok::kw_extern_weak_odr: // OptionalLinkage
     case lltok::kw_external: {    // OptionalLinkage
       unsigned Linkage, Visibility;
       if (ParseOptionalLinkage(Linkage) ||
@@ -377,7 +381,8 @@ bool LLParser::ParseAlias(const std::string &Name, LocTy NameLoc,
     return true;
 
   if (Linkage != GlobalValue::ExternalLinkage &&
-      Linkage != GlobalValue::WeakLinkage &&
+      Linkage != GlobalValue::WeakAnyLinkage &&
+      Linkage != GlobalValue::WeakODRLinkage &&
       Linkage != GlobalValue::InternalLinkage &&
       Linkage != GlobalValue::PrivateLinkage)
     return Error(LinkageLoc, "invalid linkage type for alias");
@@ -461,7 +466,8 @@ bool LLParser::ParseGlobal(const std::string &Name, LocTy NameLoc,
   // present.
   Constant *Init = 0;
   if (!HasLinkage || (Linkage != GlobalValue::DLLImportLinkage &&
-                      Linkage != GlobalValue::ExternalWeakLinkage &&
+                      Linkage != GlobalValue::ExternalWeakAnyLinkage &&
+                      Linkage != GlobalValue::ExternalWeakODRLinkage &&
                       Linkage != GlobalValue::ExternalLinkage)) {
     if (ParseGlobalValue(Ty, Init))
       return true;
@@ -576,10 +582,10 @@ GlobalValue *LLParser::GetGlobalVal(const std::string &Name, const Type *Ty,
       return 0;
     }
     
-    FwdVal = Function::Create(FT, GlobalValue::ExternalWeakLinkage, Name, M);
+    FwdVal = Function::Create(FT, GlobalValue::ExternalWeakAnyLinkage, Name, M);
   } else {
     FwdVal = new GlobalVariable(PTy->getElementType(), false,
-                                GlobalValue::ExternalWeakLinkage, 0, Name, M);
+                                GlobalValue::ExternalWeakAnyLinkage, 0, Name, M);
   }
   
   ForwardRefVals[Name] = std::make_pair(FwdVal, Loc);
@@ -620,10 +626,10 @@ GlobalValue *LLParser::GetGlobalVal(unsigned ID, const Type *Ty, LocTy Loc) {
       Error(Loc, "function may not return opaque type");
       return 0;
     }
-    FwdVal = Function::Create(FT, GlobalValue::ExternalWeakLinkage, "", M);
+    FwdVal = Function::Create(FT, GlobalValue::ExternalWeakAnyLinkage, "", M);
   } else {
     FwdVal = new GlobalVariable(PTy->getElementType(), false,
-                                GlobalValue::ExternalWeakLinkage, 0, "", M);
+                                GlobalValue::ExternalWeakAnyLinkage, 0, "", M);
   }
   
   ForwardRefValIDs[ID] = std::make_pair(FwdVal, Loc);
@@ -746,27 +752,36 @@ bool LLParser::ParseOptionalAttrs(unsigned &Attrs, unsigned AttrKind) {
 ///   ::= 'private'
 ///   ::= 'internal'
 ///   ::= 'weak'
+///   ::= 'weak_odr'
 ///   ::= 'linkonce'
+///   ::= 'linkonce_odr'
 ///   ::= 'appending'
 ///   ::= 'dllexport'
 ///   ::= 'common'
+///   ::= 'common_odr'
 ///   ::= 'dllimport'
 ///   ::= 'extern_weak'
+///   ::= 'extern_weak_odr'
 ///   ::= 'external'
 bool LLParser::ParseOptionalLinkage(unsigned &Res, bool &HasLinkage) {
   HasLinkage = false;
   switch (Lex.getKind()) {
-  default:                    Res = GlobalValue::ExternalLinkage; return false;
-  case lltok::kw_private:     Res = GlobalValue::PrivateLinkage; break;
-  case lltok::kw_internal:    Res = GlobalValue::InternalLinkage; break;
-  case lltok::kw_weak:        Res = GlobalValue::WeakLinkage; break;
-  case lltok::kw_linkonce:    Res = GlobalValue::LinkOnceLinkage; 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;
+  default:                     Res = GlobalValue::ExternalLinkage; return false;
+  case lltok::kw_private:      Res = GlobalValue::PrivateLinkage; break;
+  case lltok::kw_internal:     Res = GlobalValue::InternalLinkage; break;
+  case lltok::kw_weak:         Res = GlobalValue::WeakAnyLinkage; break;
+  case lltok::kw_weak_odr:     Res = GlobalValue::WeakODRLinkage; break;
+  case lltok::kw_linkonce:     Res = GlobalValue::LinkOnceAnyLinkage; break;
+  case lltok::kw_linkonce_odr: Res = GlobalValue::LinkOnceODRLinkage; break;
+  case lltok::kw_appending:    Res = GlobalValue::AppendingLinkage; break;
+  case lltok::kw_dllexport:    Res = GlobalValue::DLLExportLinkage; break;
+  case lltok::kw_common:       Res = GlobalValue::CommonAnyLinkage; break;
+  case lltok::kw_common_odr:   Res = GlobalValue::CommonODRLinkage; break;
+  case lltok::kw_dllimport:    Res = GlobalValue::DLLImportLinkage; break;
+  case lltok::kw_extern_weak:  Res = GlobalValue::ExternalWeakAnyLinkage; break;
+  case lltok::kw_extern_weak_odr:
+                               Res = GlobalValue::ExternalWeakODRLinkage; break;
+  case lltok::kw_external:     Res = GlobalValue::ExternalLinkage; break;
   }
   Lex.Lex();
   HasLinkage = true;
@@ -2074,21 +2089,25 @@ bool LLParser::ParseFunctionHeader(Function *&Fn, bool isDefine) {
   case GlobalValue::ExternalLinkage:
     break; // always ok.
   case GlobalValue::DLLImportLinkage:
-  case GlobalValue::ExternalWeakLinkage:
+  case GlobalValue::ExternalWeakAnyLinkage:
+  case GlobalValue::ExternalWeakODRLinkage:
     if (isDefine)
       return Error(LinkageLoc, "invalid linkage for function definition");
     break;
   case GlobalValue::PrivateLinkage:
   case GlobalValue::InternalLinkage:
-  case GlobalValue::LinkOnceLinkage:
-  case GlobalValue::WeakLinkage:
+  case GlobalValue::LinkOnceAnyLinkage:
+  case GlobalValue::LinkOnceODRLinkage:
+  case GlobalValue::WeakAnyLinkage:
+  case GlobalValue::WeakODRLinkage:
   case GlobalValue::DLLExportLinkage:
     if (!isDefine)
       return Error(LinkageLoc, "invalid linkage for function declaration");
     break;
   case GlobalValue::AppendingLinkage:
   case GlobalValue::GhostLinkage:
-  case GlobalValue::CommonLinkage:
+  case GlobalValue::CommonAnyLinkage:
+  case GlobalValue::CommonODRLinkage:
     return Error(LinkageLoc, "invalid function linkage type");
   }
   
diff --git a/lib/AsmParser/LLToken.h b/lib/AsmParser/LLToken.h
index e3bc908b6e..efdc77af81 100644
--- a/lib/AsmParser/LLToken.h
+++ b/lib/AsmParser/LLToken.h
@@ -36,9 +36,10 @@ namespace lltok {
     kw_declare, kw_define,
     kw_global,  kw_constant,
 
-    kw_private, kw_internal, kw_linkonce, kw_weak, kw_appending, kw_dllimport,
-    kw_dllexport, kw_common, kw_default, kw_hidden, kw_protected,
-    kw_extern_weak,
+    kw_private, kw_internal, kw_linkonce, kw_linkonce_odr, kw_weak, kw_weak_odr,
+    kw_appending, kw_dllimport, kw_dllexport, kw_common, kw_common_odr,
+    kw_default, kw_hidden, kw_protected,
+    kw_extern_weak, kw_extern_weak_odr,
     kw_external, kw_thread_local,
     kw_zeroinitializer,
     kw_undef, kw_null,
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 2ddfbe3a13..0fe6fc682c 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -59,15 +59,19 @@ static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
   switch (Val) {
   default: // Map unknown/new linkages to external
   case 0: return GlobalValue::ExternalLinkage;
-  case 1: return GlobalValue::WeakLinkage;
+  case 1: return GlobalValue::WeakAnyLinkage;
   case 2: return GlobalValue::AppendingLinkage;
   case 3: return GlobalValue::InternalLinkage;
-  case 4: return GlobalValue::LinkOnceLinkage;
+  case 4: return GlobalValue::LinkOnceAnyLinkage;
   case 5: return GlobalValue::DLLImportLinkage;
   case 6: return GlobalValue::DLLExportLinkage;
-  case 7: return GlobalValue::ExternalWeakLinkage;
-  case 8: return GlobalValue::CommonLinkage;
+  case 7: return GlobalValue::ExternalWeakAnyLinkage;
+  case 8: return GlobalValue::CommonAnyLinkage;
   case 9: return GlobalValue::PrivateLinkage;
+  case 10: return GlobalValue::WeakODRLinkage;
+  case 11: return GlobalValue::LinkOnceODRLinkage;
+  case 12: return GlobalValue::ExternalWeakODRLinkage;
+  case 13: return GlobalValue::CommonODRLinkage;
   }
 }
 
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 5633f0ffad..fefffbedb6 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -276,15 +276,19 @@ static unsigned getEncodedLinkage(const GlobalValue *GV) {
   default: assert(0 && "Invalid linkage!");
   case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
   case GlobalValue::ExternalLinkage:     return 0;
-  case GlobalValue::WeakLinkage:         return 1;
+  case GlobalValue::WeakAnyLinkage:      return 1;
   case GlobalValue::AppendingLinkage:    return 2;
   case GlobalValue::InternalLinkage:     return 3;
-  case GlobalValue::LinkOnceLinkage:     return 4;
+  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::ExternalWeakAnyLinkage: return 7;
+  case GlobalValue::CommonAnyLinkage:    return 8;
   case GlobalValue::PrivateLinkage:      return 9;
+  case GlobalValue::WeakODRLinkage:      return 10;
+  case GlobalValue::LinkOnceODRLinkage:  return 11;
+  case GlobalValue::ExternalWeakODRLinkage: return 12;
+  case GlobalValue::CommonODRLinkage:    return 13;
   }
 }
 
diff --git a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
index 5c4957aba1..9181216b5a 100644
--- a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
@@ -3135,9 +3135,8 @@ public:
     GlobalVariable *GV = getGlobalVariable(V);
     if (!GV)
       return false;
-    
-    if (GV->getLinkage() != GlobalValue::InternalLinkage
-        && GV->getLinkage() != GlobalValue::LinkOnceLinkage)
+
+    if (!GV->hasInternalLinkage () && !GV->hasLinkOnceLinkage())
       return false;
 
     DIDescriptor DI(GV);
@@ -3449,8 +3448,10 @@ class DwarfException : public Dwarf  {
     }
 
     // If corresponding function is weak definition, this should be too.
-    if ((linkage == Function::WeakLinkage ||
-         linkage == Function::LinkOnceLinkage) &&
+    if ((linkage == Function::WeakAnyLinkage ||
+         linkage == Function::WeakODRLinkage ||
+         linkage == Function::LinkOnceAnyLinkage ||
+         linkage == Function::LinkOnceODRLinkage) &&
         TAI->getWeakDefDirective())
       O << TAI->getWeakDefDirective() << EHFrameInfo.FnName << "\n";
 
@@ -3461,8 +3462,10 @@ class DwarfException : public Dwarf  {
     // unwind info is to be available for non-EH uses.
     if (!EHFrameInfo.hasCalls &&
         !UnwindTablesMandatory &&
-        ((linkage != Function::WeakLinkage &&
-          linkage != Function::LinkOnceLinkage) ||
+        ((linkage != Function::WeakAnyLinkage &&
+          linkage != Function::WeakODRLinkage &&
+          linkage != Function::LinkOnceAnyLinkage &&
+          linkage != Function::LinkOnceODRLinkage) ||
          !TAI->getWeakDefDirective() ||
          TAI->getSupportsWeakOmittedEHFrame()))
     {
diff --git a/lib/CodeGen/ELFWriter.cpp b/lib/CodeGen/ELFWriter.cpp
index 7cca74b1fb..ddc4e3588b 100644
--- a/lib/CodeGen/ELFWriter.cpp
+++ b/lib/CodeGen/ELFWriter.cpp
@@ -174,8 +174,10 @@ bool ELFCodeEmitter::finishFunction(MachineFunction &F) {
   case GlobalValue::ExternalLinkage:
     FnSym.SetBind(ELFWriter::ELFSym::STB_GLOBAL);
     break;
-  case GlobalValue::LinkOnceLinkage:
-  case GlobalValue::WeakLinkage:
+  case GlobalValue::LinkOnceAnyLinkage:
+  case GlobalValue::LinkOnceODRLinkage:
+  case GlobalValue::WeakAnyLinkage:
+  case GlobalValue::WeakODRLinkage:
     FnSym.SetBind(ELFWriter::ELFSym::STB_WEAK);
     break;
   case GlobalValue::PrivateLinkage:
diff --git a/lib/CodeGen/IntrinsicLowering.cpp b/lib/CodeGen/IntrinsicLowering.cpp
index 5b4de27b8a..56b1736b41 100644
--- a/lib/CodeGen/IntrinsicLowering.cpp
+++ b/lib/CodeGen/IntrinsicLowering.cpp
@@ -316,7 +316,7 @@ static Instruction *LowerPartSelect(CallInst *CI) {
       Name[i] = '_';
   Module* M = F->getParent();
   F = cast<Function>(M->getOrInsertFunction(Name, FT));
-  F->setLinkage(GlobalValue::WeakLinkage);
+  F->setLinkage(GlobalValue::WeakAnyLinkage);
 
   // If we haven't defined the impl function yet, do so now
   if (F->isDeclaration()) {
@@ -490,7 +490,7 @@ static Instruction *LowerPartSet(CallInst *CI) {
       Name[i] = '_';
   Module* M = F->getParent();
   F = cast<Function>(M->getOrInsertFunction(Name, FT));
-  F->setLinkage(GlobalValue::WeakLinkage);
+  F->setLinkage(GlobalValue::WeakAnyLinkage);
 
   // If we haven't defined the impl function yet, do so now
   if (F->isDeclaration()) {
diff --git a/lib/CodeGen/MachOWriter.cpp b/lib/CodeGen/MachOWriter.cpp
index 22c21578ec..5fe05a4e8f 100644
--- a/lib/CodeGen/MachOWriter.cpp
+++ b/lib/CodeGen/MachOWriter.cpp
@@ -956,9 +956,12 @@ MachOSym::MachOSym(const GlobalValue *gv, std::string name, uint8_t sect,
   default:
     assert(0 && "Unexpected linkage type!");
     break;
-  case GlobalValue::WeakLinkage:
-  case GlobalValue::LinkOnceLinkage:
-  case GlobalValue::CommonLinkage:
+  case GlobalValue::WeakAnyLinkage:
+  case GlobalValue::WeakODRLinkage:
+  case GlobalValue::LinkOnceAnyLinkage:
+  case GlobalValue::LinkOnceODRLinkage:
+  case GlobalValue::CommonAnyLinkage:
+  case GlobalValue::CommonODRLinkage:
     assert(!isa<Function>(gv) && "Unexpected linkage type for Function!");
   case GlobalValue::ExternalLinkage:
     GVName = TAI->getGlobalPrefix() + name;
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 7913c01963..a08dcb2e49 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -728,7 +728,7 @@ TargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
   if (getTargetMachine().getRelocationModel() == Reloc::DynamicNoPIC &&
       GA &&
       !GA->getGlobal()->isDeclaration() &&
-      !GA->getGlobal()->mayBeOverridden())
+      !GA->getGlobal()->isWeakForLinker())
     return true;
 
   // Otherwise assume nothing is safe.
diff --git a/lib/CodeGen/ShadowStackGC.cpp b/lib/CodeGen/ShadowStackGC.cpp
index 5a55760c7c..2402f81bb0 100644
--- a/lib/CodeGen/ShadowStackGC.cpp
+++ b/lib/CodeGen/ShadowStackGC.cpp
@@ -293,12 +293,12 @@ bool ShadowStackGC::initializeCustomLowering(Module &M) {
     // If the root chain does not exist, insert a new one with linkonce
     // linkage!
     Head = new GlobalVariable(StackEntryPtrTy, false,
-                              GlobalValue::LinkOnceLinkage,
+                              GlobalValue::LinkOnceAnyLinkage,
                               Constant::getNullValue(StackEntryPtrTy),
                               "llvm_gc_root_chain", &M);
   } else if (Head->hasExternalLinkage() && Head->isDeclaration()) {
     Head->setInitializer(Constant::getNullValue(StackEntryPtrTy));
-    Head->setLinkage(GlobalValue::LinkOnceLinkage);
+    Head->setLinkage(GlobalValue::LinkOnceAnyLinkage);
   }
 
   return true;
diff --git a/lib/ExecutionEngine/JIT/JIT.cpp b/lib/ExecutionEngine/JIT/JIT.cpp
index 386c3beedd..0490343b86 100644
--- a/lib/ExecutionEngine/JIT/JIT.cpp
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -580,8 +580,8 @@ void *JIT::getPointerToFunction(Function *F) {
   }
 
   if (F->isDeclaration()) {
-    bool AbortOnFailure = !areDlsymStubsEnabled() &&
-                          F->getLinkage() != GlobalValue::ExternalWeakLinkage;
+    bool AbortOnFailure =
+      !areDlsymStubsEnabled() && !F->hasExternalWeakLinkage();
     void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);
     addGlobalMapping(F, Addr);
     return Addr;
diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index c596812e0c..6ea3005e75 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -460,7 +460,7 @@ static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
         LT = Src->getLinkage();
       }
     } else if (Dest->hasExternalWeakLinkage()) {
-      //If the Dest is weak, use the source linkage
+      // If the Dest is weak, use the source linkage.
       LinkFromSrc = true;
       LT = Src->getLinkage();
     } else {
@@ -683,15 +683,22 @@ static bool LinkGlobals(Module *Dest, const Module *Src,
 
 static GlobalValue::LinkageTypes
 CalculateAliasLinkage(const GlobalValue *SGV, const GlobalValue *DGV) {
-  if (SGV->hasExternalLinkage() || DGV->hasExternalLinkage())
+  GlobalValue::LinkageTypes SL = SGV->getLinkage();
+  GlobalValue::LinkageTypes DL = DGV->getLinkage();
+  if (SL == GlobalValue::ExternalLinkage || DL == GlobalValue::ExternalLinkage)
     return GlobalValue::ExternalLinkage;
-  else if (SGV->hasWeakLinkage() || DGV->hasWeakLinkage())
-    return GlobalValue::WeakLinkage;
-  else if (SGV->hasInternalLinkage() && DGV->hasInternalLinkage())
+  else if (SL == GlobalValue::WeakAnyLinkage ||
+           DL == GlobalValue::WeakAnyLinkage)
+    return GlobalValue::WeakAnyLinkage;
+  else if (SL == GlobalValue::WeakODRLinkage ||
+           DL == GlobalValue::WeakODRLinkage)
+    return GlobalValue::WeakODRLinkage;
+  else if (SL == GlobalValue::InternalLinkage &&
+           DL == GlobalValue::InternalLinkage)
     return GlobalValue::InternalLinkage;
   else {
-    assert (SGV->hasPrivateLinkage() && DGV->hasPrivateLinkage() &&
-	    "Unexpected linkage type");
+    assert (SL == GlobalValue::PrivateLinkage &&
+            DL == GlobalValue::PrivateLinkage && "Unexpected linkage type");
     return GlobalValue::PrivateLinkage;
   }
 }
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 41852fa594..cc38efb9cc 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -854,7 +854,7 @@ static bool GVIsIndirectSymbol(GlobalValue *GV, Reloc::Model RelocM) {
   bool isDecl = GV->isDeclaration() && !GV->hasNotBeenReadFromBitcode();
   if (GV->hasHiddenVisibility() && (!isDecl && !GV->hasCommonLinkage()))
     return false;
-  return RelocM != Reloc::Static && (isDecl || GV->mayBeOverridden());
+  return RelocM != Reloc::Static && (isDecl || GV->isWeakForLinker());
 }
 
 SDValue ARMTargetLowering::LowerGlobalAddressDarwin(SDValue Op,
diff --git a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
index 969b8face4..ae968e7b09 100644
--- a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
+++ b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
@@ -208,8 +208,10 @@ bool ARMAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
     SwitchToTextSection("\t.text", F);
     O << "\t.globl\t" << CurrentFnName << "\n";
     break;
-  case Function::WeakLinkage:
-  case Function::LinkOnceLinkage:
+  case Function::WeakAnyLinkage:
+  case Function::WeakODRLinkage:
+  case Function::LinkOnceAnyLinkage:
+  case Function::LinkOnceODRLinkage:
     if (Subtarget->isTargetDarwin()) {
       SwitchToTextSection(
                 ".section __TEXT,__textcoal_nt,coalesced,pure_instructions", F);
@@ -853,7 +855,7 @@ void ARMAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
       }
     }
 
-    if (GVar->hasLocalLinkage() || GVar->mayBeOverridden()) {
+    if (GVar->hasLocalLinkage() || GVar->isWeakForLinker()) {
       if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 
       if (isDarwin) {
@@ -899,9 +901,12 @@ void ARMAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
 
   SwitchToSection(TAI->SectionForGlobal(GVar));
   switch (GVar->getLinkage()) {
-   case GlobalValue::CommonLinkage:
-   case GlobalValue::LinkOnceLinkage:
-   case GlobalValue::WeakLinkage:
+   case GlobalValue::CommonAnyLinkage:
+   case GlobalValue::CommonODRLinkage:
+   case GlobalValue::LinkOnceAnyLinkage:
+   case GlobalValue::LinkOnceODRLinkage:
+   case GlobalValue::WeakAnyLinkage:
+   case GlobalValue::WeakODRLinkage:
     if (isDarwin) {
       O << "\t.globl " << name << "\n"
         << "\t.weak_definition " << name << "\n";
diff --git a/lib/Target/Alpha/AsmPrinter/AlphaAsmPrinter.cpp b/lib/Target/Alpha/AsmPrinter/AlphaAsmPrinter.cpp
index 536e5920f3..5238b79d9d 100644
--- a/lib/Target/Alpha/AsmPrinter/AlphaAsmPrinter.cpp
+++ b/lib/Target/Alpha/AsmPrinter/AlphaAsmPrinter.cpp
@@ -163,8 +163,10 @@ bool AlphaAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
    case Function::ExternalLinkage:
      O << "\t.globl " << CurrentFnName << "\n";
      break;
-  case Function::WeakLinkage:
-  case Function::LinkOnceLinkage:
+  case Function::WeakAnyLinkage:
+  case Function::WeakODRLinkage:
+  case Function::LinkOnceAnyLinkage:
+  case Function::LinkOnceODRLinkage:
     O << TAI->getWeakRefDirective() << CurrentFnName << "\n";
     break;
   }
@@ -231,9 +233,12 @@ void AlphaAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
 
   // 2: Kind
   switch (GVar->getLinkage()) {
-   case GlobalValue::LinkOnceLinkage:
-   case GlobalValue::WeakLinkage:
-   case GlobalValue::CommonLinkage:
+   case GlobalValue::LinkOnceAnyLinkage:
+   case GlobalValue::LinkOnceODRLinkage:
+   case GlobalValue::WeakAnyLinkage:
+   case GlobalValue::WeakODRLinkage:
+   case GlobalValue::CommonAnyLinkage:
+   case GlobalValue::CommonODRLinkage:
     O << TAI->getWeakRefDirective() << name << '\n';
     break;
    case GlobalValue::AppendingLinkage:
diff --git a/lib/Target/CellSPU/AsmPrinter/SPUAsmPrinter.cpp b/lib/Target/CellSPU/AsmPrinter/SPUAsmPrinter.cpp
index f784d70f44..7731a9023a 100644
--- a/lib/Target/CellSPU/AsmPrinter/SPUAsmPrinter.cpp
+++ b/lib/Target/CellSPU/AsmPrinter/SPUAsmPrinter.cpp
@@ -445,8 +445,10 @@ LinuxAsmPrinter::runOnMachineFunction(MachineFunction &MF)
     O << "\t.global\t" << CurrentFnName << "\n"
       << "\t.type\t" << CurrentFnName << ", @function\n";
     break;
-  case Function::WeakLinkage:
-  case Function::LinkOnceLinkage:
+  case Function::WeakAnyLinkage:
+  case Function::WeakODRLinkage:
+  case Function::LinkOnceAnyLinkage:
+  case Function::LinkOnceODRLinkage:
     O << "\t.global\t" << CurrentFnName << "\n";
     O << "\t.weak_definition\t" << CurrentFnName << "\n";
     break;
@@ -534,7 +536,7 @@ void LinuxAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
   if (C->isNullValue() && /* FIXME: Verify correct */
       !GVar->hasSection() &&
       (GVar->hasLocalLinkage() || GVar->hasExternalLinkage() ||
-       GVar->mayBeOverridden())) {
+       GVar->isWeakForLinker())) {
       if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 
       if (GVar->hasExternalLinkage()) {
@@ -555,9 +557,12 @@ void LinuxAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
 
   switch (GVar->getLinkage()) {
     // Should never be seen for the CellSPU platform...
-   case GlobalValue::LinkOnceLinkage:
-   case GlobalValue::WeakLinkage:
-   case GlobalValue::CommonLinkage:
+   case GlobalValue::LinkOnceAnyLinkage:
+   case GlobalValue::LinkOnceODRLinkage:
+   case GlobalValue::WeakAnyLinkage:
+   case GlobalValue::WeakODRLinkage:
+   case GlobalValue::CommonAnyLinkage:
+   case GlobalValue::CommonODRLinkage:
     O << "\t.global " << name << '\n'
       << "\t.type " << name << ", @object\n"
       << "\t.weak " << name << '\n';
diff --git a/lib/Target/CppBackend/CPPBackend.cpp b/lib/Target/CppBackend/CPPBackend.cpp
index dbe4f2d2d3..48cf4959e0 100644
--- a/lib/Target/CppBackend/CPPBackend.cpp
+++ b/lib/Target/CppBackend/CPPBackend.cpp
@@ -294,10 +294,14 @@ namespace {
       Out << "GlobalValue::InternalLinkage"; break;
     case GlobalValue::PrivateLinkage:
       Out << "GlobalValue::PrivateLinkage"; break;
-    case GlobalValue::LinkOnceLinkage:
-      Out << "GlobalValue::LinkOnceLinkage "; break;
-    case GlobalValue::WeakLinkage:
-      Out << "GlobalValue::WeakLinkage"; break;
+    case GlobalValue::LinkOnceAnyLinkage:
+      Out << "GlobalValue::LinkOnceAnyLinkage "; break;
+    case GlobalValue::LinkOnceODRLinkage:
+      Out << "GlobalValue::LinkOnceODRLinkage "; break;
+    case GlobalValue::WeakAnyLinkage:
+      Out << "GlobalValue::WeakAnyLinkage"; break;
+    case GlobalValue::WeakODRLinkage:
+      Out << "GlobalValue::WeakODRLinkage"; break;
     case GlobalValue::AppendingLinkage:
       Out << "GlobalValue::AppendingLinkage"; break;
     case GlobalValue::ExternalLinkage:
@@ -306,12 +310,16 @@ namespace {
       Out << "GlobalValue::DLLImportLinkage"; break;
     case GlobalValue::DLLExportLinkage:
       Out << "GlobalValue::DLLExportLinkage"; break;
-    case GlobalValue::ExternalWeakLinkage:
-      Out << "GlobalValue::ExternalWeakLinkage"; break;
+    case GlobalValue::ExternalWeakAnyLinkage:
+      Out << "GlobalValue::ExternalWeakAnyLinkage"; break;
+    case GlobalValue::ExternalWeakODRLinkage:
+      Out << "GlobalValue::ExternalWeakODRLinkage"; break;
     case GlobalValue::GhostLinkage:
       Out << "GlobalValue::GhostLinkage"; break;
-    case GlobalValue::CommonLinkage:
-      Out << "GlobalValue::CommonLinkage"; break;
+    case GlobalValue::CommonAnyLinkage:
+      Out << "GlobalValue::CommonAnyLinkage"; break;
+    case GlobalValue::CommonODRLinkage:
+      Out << "GlobalValue::CommonODRLinkage"; break;
     }
   }
 
diff --git a/lib/Target/DarwinTargetAsmInfo.cpp b/lib/Target/DarwinTargetAsmInfo.cpp
index cc05c09c51..927fdd2953 100644
--- a/lib/Target/DarwinTargetAsmInfo.cpp
+++ b/lib/Target/DarwinTargetAsmInfo.cpp
@@ -75,7 +75,7 @@ DarwinTargetAsmInfo::emitUsedDirectiveFor(const GlobalValue* GV,
 const Section*
 DarwinTargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV) const {
   SectionKind::Kind Kind = SectionKindForGlobal(GV);
-  bool isWeak = GV->mayBeOverridden();
+  bool isWeak = GV->isWeakForLinker();
   bool isNonStatic = TM.getRelocationModel() != Reloc::Static;
 
   switch (Kind) {
diff --git a/lib/Target/ELFTargetAsmInfo.cpp b/lib/Target/ELFTargetAsmInfo.cpp
index 624b95c7b6..3a2a00c658 100644
--- a/lib/Target/ELFTargetAsmInfo.cpp
+++ b/lib/Target/ELFTargetAsmInfo.cpp
@@ -49,14 +49,16 @@ ELFTargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV) const {
      case Function::DLLExportLinkage:
      case Function::ExternalLinkage:
       return TextSection;
-     case Function::WeakLinkage:
-     case Function::LinkOnceLinkage:
+     case Function::WeakAnyLinkage:
+     case Function::WeakODRLinkage:
+     case Function::LinkOnceAnyLinkage:
+     case Function::LinkOnceODRLinkage:
       std::string Name = UniqueSectionForGlobal(GV, Kind);
       unsigned Flags = SectionFlagsForGlobal(GV, Name.c_str());
       return getNamedSection(Name.c_str(), Flags);
     }
   } else if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) {
-    if (GVar->mayBeOverridden()) {
+    if (GVar->isWeakForLinker()) {
       std::string Name = UniqueSectionForGlobal(GVar, Kind);
       unsigned Flags = SectionFlagsForGlobal(GVar, Name.c_str());
       return getNamedSection(Name.c_str(), Flags);
diff --git a/lib/Target/IA64/IA64AsmPrinter.cpp b/lib/Target/IA64/IA64AsmPrinter.cpp
index 00474309d5..d8ec2108c9 100644
--- a/lib/Target/IA64/IA64AsmPrinter.cpp
+++ b/lib/Target/IA64/IA64AsmPrinter.cpp
@@ -278,7 +278,7 @@ void IA64AsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
 
   if (C->isNullValue() && !GVar->hasSection()) {
     if (!GVar->isThreadLocal() &&
-        (GVar->hasLocalLinkage() || GVar->mayBeOverridden())) {
+        (GVar->hasLocalLinkage() || GVar->isWeakForLinker())) {
       if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 
       if (GVar->hasLocalLinkage()) {
@@ -296,9 +296,12 @@ void IA64AsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
   }
 
   switch (GVar->getLinkage()) {
-   case GlobalValue::LinkOnceLinkage:
-   case GlobalValue::CommonLinkage:
-   case GlobalValue::WeakLinkage:
+   case GlobalValue::LinkOnceAnyLinkage:
+   case GlobalValue::LinkOnceODRLinkage:
+   case GlobalValue::CommonAnyLinkage:
+   case GlobalValue::CommonODRLinkage:
+   case GlobalValue::WeakAnyLinkage:
+   case GlobalValue::WeakODRLinkage:
     // Nonnull linkonce -> weak
     O << "\t.weak " << name << '\n';
     break;
diff --git a/lib/Target/Mips/MipsAsmPrinter.cpp b/lib/Target/Mips/MipsAsmPrinter.cpp
index 732c5d796c..a22d7d6ebc 100644
--- a/lib/Target/Mips/MipsAsmPrinter.cpp
+++ b/lib/Target/Mips/MipsAsmPrinter.cpp
@@ -504,7 +504,7 @@ printModuleLevelGV(const GlobalVariable* GVar) {
 
   if (C->isNullValue() && !GVar->hasSection()) {
     if (!GVar->isThreadLocal() &&
-        (GVar->hasLocalLinkage() || GVar->mayBeOverridden())) {
+        (GVar->hasLocalLinkage() || GVar->isWeakForLinker())) {
       if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 
       if (GVar->hasLocalLinkage())
@@ -519,9 +519,12 @@ printModuleLevelGV(const GlobalVariable* GVar) {
     }
   }
   switch (GVar->getLinkage()) {
-   case GlobalValue::LinkOnceLinkage:
-   case GlobalValue::CommonLinkage:
-   case GlobalValue::WeakLinkage:
+   case GlobalValue::LinkOnceAnyLinkage:
+   case GlobalValue::LinkOnceODRLinkage:
+   case GlobalValue::CommonAnyLinkage:
+   case GlobalValue::CommonODRLinkage:
+   case GlobalValue::WeakAnyLinkage:
+   case GlobalValue::WeakODRLinkage:
     // FIXME: Verify correct for weak.
     // Nonnull linkonce -> weak
     O << "\t.weak " << name << '\n';
diff --git a/lib/Target/Mips/MipsTargetAsmInfo.cpp b/lib/Target/Mips/MipsTargetAsmInfo.cpp
index 7566f41eaf..3eee3beef1 100644
--- a/lib/Target/Mips/MipsTargetAsmInfo.cpp
+++ b/lib/Target/Mips/MipsTargetAsmInfo.cpp
@@ -85,7 +85,7 @@ SelectSectionForGlobal(const GlobalValue *GV) const {
   SectionKind::Kind K = SectionKindForGlobal(GV);
   const GlobalVariable *GVA = dyn_cast<GlobalVariable>(GV);
 
-  if (GVA && (!GVA->mayBeOverridden()))
+  if (GVA && (!GVA->isWeakForLinker()))
     switch (K) {
       case SectionKind::SmallData:
         return getSmallDataSection();
diff --git a/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp b/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
index 57a2697112..4da53774d7 100644
--- a/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
+++ b/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
@@ -388,7 +388,7 @@ void PPCAsmPrinter::printOp(const MachineOperand &MO) {
 
     // External or weakly linked global variables need non-lazily-resolved stubs
     if (TM.getRelocationModel() != Reloc::Static) {
-      if (GV->isDeclaration() || GV->mayBeOverridden()) {
+      if (GV->isDeclaration() || GV->isWeakForLinker()) {
         if (GV->hasHiddenVisibility()) {
           if (!GV->isDeclaration() && !GV->hasCommonLinkage())
             O << Name;
@@ -592,8 +592,10 @@ bool PPCLinuxAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
     O << "\t.global\t" << CurrentFnName << '\n'
       << "\t.type\t" << CurrentFnName << ", @function\n";
     break;
-  case Function::WeakLinkage:
-  case Function::LinkOnceLinkage:
+  case Function::WeakAnyLinkage:
+  case Function::WeakODRLinkage:
+  case Function::LinkOnceAnyLinkage:
+  case Function::LinkOnceODRLinkage:
     O << "\t.global\t" << CurrentFnName << '\n';
     O << "\t.weak\t" << CurrentFnName << '\n';
     break;
@@ -689,7 +691,7 @@ void PPCLinuxAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
   if (C->isNullValue() && /* FIXME: Verify correct */
       !GVar->hasSection() &&
       (GVar->hasLocalLinkage() || GVar->hasExternalLinkage() ||
-       GVar->mayBeOverridden())) {
+       GVar->isWeakForLinker())) {
       if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 
       if (GVar->hasExternalLinkage()) {
@@ -709,9 +711,12 @@ void PPCLinuxAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
   }
 
   switch (GVar->getLinkage()) {
-   case GlobalValue::LinkOnceLinkage:
-   case GlobalValue::WeakLinkage:
-   case GlobalValue::CommonLinkage:
+   case GlobalValue::LinkOnceAnyLinkage:
+   case GlobalValue::LinkOnceODRLinkage:
+   case GlobalValue::WeakAnyLinkage:
+   case GlobalValue::WeakODRLinkage:
+   case GlobalValue::CommonAnyLinkage:
+   case GlobalValue::CommonODRLinkage:
     O << "\t.global " << name << '\n'
       << "\t.type " << name << ", @object\n"
       << "\t.weak " << name << '\n';
@@ -785,8 +790,10 @@ bool PPCDarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
   case Function::ExternalLinkage:
     O << "\t.globl\t" << CurrentFnName << '\n';
     break;
-  case Function::WeakLinkage:
-  case Function::LinkOnceLinkage:
+  case Function::WeakAnyLinkage:
+  case Function::WeakODRLinkage:
+  case Function::LinkOnceAnyLinkage:
+  case Function::LinkOnceODRLinkage:
     O << "\t.globl\t" << CurrentFnName << '\n';
     O << "\t.weak_definition\t" << CurrentFnName << '\n';
     break;
@@ -918,7 +925,7 @@ void PPCDarwinAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
   if (C->isNullValue() && /* FIXME: Verify correct */
       !GVar->hasSection() &&
       (GVar->hasLocalLinkage() || GVar->hasExternalLinkage() ||
-       GVar->mayBeOverridden()) &&
+       GVar->isWeakForLinker()) &&
       TAI->SectionKindForGlobal(GVar) != SectionKind::RODataMergeStr) {
     if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 
@@ -950,9 +957,12 @@ void PPCDarwinAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
   }
 
   switch (GVar->getLinkage()) {
-   case GlobalValue::LinkOnceLinkage:
-   case GlobalValue::WeakLinkage:
-   case GlobalValue::CommonLinkage:
+   case GlobalValue::LinkOnceAnyLinkage:
+   case GlobalValue::LinkOnceODRLinkage:
+   case GlobalValue::WeakAnyLinkage:
+   case GlobalValue::WeakODRLinkage:
+   case GlobalValue::CommonAnyLinkage:
+   case GlobalValue::CommonODRLinkage:
     O << "\t.globl " << name << '\n'
       << "\t.weak_definition " << name << '\n';
     break;
diff --git a/lib/Target/Sparc/AsmPrinter/SparcAsmPrinter.cpp b/lib/Target/Sparc/AsmPrinter/SparcAsmPrinter.cpp
index 80976bb259..e0785d5582 100644
--- a/lib/Target/Sparc/AsmPrinter/SparcAsmPrinter.cpp
+++ b/lib/Target/Sparc/AsmPrinter/SparcAsmPrinter.cpp
@@ -260,7 +260,7 @@ void SparcAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
 
   if (C->isNullValue() && !GVar->hasSection()) {
     if (!GVar->isThreadLocal() &&
-        (GVar->hasLocalLinkage() || GVar->mayBeOverridden())) {
+        (GVar->hasLocalLinkage() || GVar->isWeakForLinker())) {
       if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 
       if (GVar->hasLocalLinkage())
@@ -276,9 +276,12 @@ void SparcAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
   }
 
   switch (GVar->getLinkage()) {
-   case GlobalValue::CommonLinkage:
-   case GlobalValue::LinkOnceLinkage:
-   case GlobalValue::WeakLinkage:   // FIXME: Verify correct for weak.
+   case GlobalValue::CommonAnyLinkage:
+   case GlobalValue::CommonODRLinkage:
+   case GlobalValue::LinkOnceAnyLinkage:
+   case GlobalValue::LinkOnceODRLinkage:
+   case GlobalValue::WeakAnyLinkage: // FIXME: Verify correct for weak.
+   case GlobalValue::WeakODRLinkage: // FIXME: Verify correct for weak.
     // Nonnull linkonce -> weak
     O << "\t.weak " << name << '\n';
     break;
diff --git a/lib/Target/TargetAsmInfo.cpp b/lib/Target/TargetAsmInfo.cpp
index d687e2f44c..8f5941fb9e 100644
--- a/lib/Target/TargetAsmInfo.cpp
+++ b/lib/Target/TargetAsmInfo.cpp
@@ -259,7 +259,7 @@ TargetAsmInfo::SectionFlagsForGlobal(const GlobalValue *GV,
       assert(0 && "Unexpected section kind!");
     }
 
-    if (GV->mayBeOverridden())
+    if (GV->isWeakForLinker())
       Flags |= SectionFlags::Linkonce;
   }
 
@@ -310,7 +310,7 @@ const Section*
 TargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV) const {
   SectionKind::Kind Kind = SectionKindForGlobal(GV);
 
-  if (GV->mayBeOverridden()) {
+  if (GV->isWeakForLinker()) {
     std::string Name = UniqueSectionForGlobal(GV, Kind);
     unsigned Flags = SectionFlagsForGlobal(GV, Name.c_str());
     return getNamedSection(Name.c_str(), Flags);
diff --git a/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp b/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp
index 0595b6fbd1..e3b6c27dcb 100644
--- a/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp
+++ b/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp
@@ -168,8 +168,10 @@ void X86ATTAsmPrinter::emitFunctionHeader(const MachineFunction &MF) {
     EmitAlignment(FnAlign, F);
     O << "\t.globl\t" << CurrentFnName << '\n';
     break;
-  case Function::LinkOnceLinkage:
-  case Function::WeakLinkage:
+  case Function::LinkOnceAnyLinkage:
+  case Function::LinkOnceODRLinkage:
+  case Function::WeakAnyLinkage:
+  case Function::WeakODRLinkage:
     EmitAlignment(FnAlign, F);
     if (Subtarget->isTargetDarwin()) {
       O << "\t.globl\t" << CurrentFnName << '\n';
@@ -198,8 +200,7 @@ void X86ATTAsmPrinter::emitFunctionHeader(const MachineFunction &MF) {
   O << CurrentFnName << ":\n";
   // Add some workaround for linkonce linkage on Cygwin\MinGW
   if (Subtarget->isTargetCygMing() &&
-      (F->getLinkage() == Function::LinkOnceLinkage ||
-       F->getLinkage() == Function::WeakLinkage))
+      (F->hasLinkOnceLinkage() || F->hasWeakLinkage()))
     O << "Lllvm$workaround$fake$stub$" << CurrentFnName << ":\n";
 }
 
@@ -386,7 +387,7 @@ void X86ATTAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
     if (shouldPrintStub(TM, Subtarget)) {
       // Link-once, declaration, or Weakly-linked global variables need
       // non-lazily-resolved stubs
-      if (GV->isDeclaration() || GV->mayBeOverridden()) {
+      if (GV->isDeclaration() || GV->isWeakForLinker()) {
         // Dynamically-resolved functions need a stub for the function.
         if (isCallOp && isa<Function>(GV)) {
           // Function stubs are no longer needed for Mac OS X 10.5 and up.
@@ -816,7 +817,7 @@ void X86ATTAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
     }
 
     if (!GVar->isThreadLocal() &&
-        (GVar->hasLocalLinkage() || GVar->mayBeOverridden())) {
+        (GVar->hasLocalLinkage() || GVar->isWeakForLinker())) {
       if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 
       if (TAI->getLCOMMDirective() != NULL) {
@@ -855,9 +856,12 @@ void X86ATTAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
   }
 
   switch (GVar->getLinkage()) {
-  case GlobalValue::CommonLinkage:
-  case GlobalValue::LinkOnceLinkage:
-  case GlobalValue::WeakLinkage:
+  case GlobalValue::CommonAnyLinkage:
+  case GlobalValue::CommonODRLinkage:
+  case GlobalValue::LinkOnceAnyLinkage:
+  case GlobalValue::LinkOnceODRLinkage:
+  case GlobalValue::WeakAnyLinkage:
+  case GlobalValue::WeakODRLinkage:
     if (Subtarget->isTargetDarwin()) {
       O << "\t.globl " << name << '\n'
         << TAI->getWeakDefDirective() << name << '\n';
diff --git a/lib/Target/X86/AsmPrinter/X86IntelAsmPrinter.cpp b/lib/Target/X86/AsmPrinter/X86IntelAsmPrinter.cpp
index c4389aa406..12b9c2fd4a 100644
--- a/lib/Target/X86/AsmPrinter/X86IntelAsmPrinter.cpp
+++ b/lib/Target/X86/AsmPrinter/X86IntelAsmPrinter.cpp
@@ -455,9 +455,12 @@ bool X86IntelAsmPrinter::doFinalization(Module &M) {
     bool bCustomSegment = false;
 
     switch (I->getLinkage()) {
-    case GlobalValue::CommonLinkage:
-    case GlobalValue::LinkOnceLinkage:
-    case GlobalValue::WeakLinkage:
+    case GlobalValue::CommonAnyLinkage:
+    case GlobalValue::CommonODRLinkage:
+    case GlobalValue::LinkOnceAnyLinkage:
+    case GlobalValue::LinkOnceODRLinkage:
+    case GlobalValue::WeakAnyLinkage:
+    case GlobalValue::WeakODRLinkage:
       SwitchToDataSection("");
       O << name << "?\tsegment common 'COMMON'\n";
       bCustomSegment = true;
diff --git a/lib/Target/X86/X86Subtarget.cpp b/lib/Target/X86/X86Subtarget.cpp
index 6d2602a2ce..8c5176bc83 100644
--- a/lib/Target/X86/X86Subtarget.cpp
+++ b/lib/Target/X86/X86Subtarget.cpp
@@ -51,7 +51,7 @@ bool X86Subtarget::GVRequiresExtraLoad(const GlobalValue* GV,
         // target is x86-64 or the symbol is definitely defined in the current
         // translation unit.
         return false;
-      return !isDirectCall && (isDecl || GV->mayBeOverridden());
+      return !isDirectCall && (isDecl || GV->isWeakForLinker());
     } else if (isTargetELF()) {
       // Extra load is needed for all externally visible.
       if (isDirectCall)
diff --git a/lib/Target/XCore/XCoreAsmPrinter.cpp b/lib/Target/XCore/XCoreAsmPrinter.cpp
index 3a30f107d8..6026e126d1 100644
--- a/lib/Target/XCore/XCoreAsmPrinter.cpp
+++ b/lib/Target/XCore/XCoreAsmPrinter.cpp
@@ -188,8 +188,10 @@ emitGlobal(const GlobalVariable *GV)
     case GlobalValue::AppendingLinkage:
       cerr << "AppendingLinkage is not supported by this target!\n";
       abort();
-    case GlobalValue::LinkOnceLinkage:
-    case GlobalValue::WeakLinkage:
+    case GlobalValue::LinkOnceAnyLinkage:
+    case GlobalValue::LinkOnceODRLinkage:
+    case GlobalValue::WeakAnyLinkage:
+    case GlobalValue::WeakODRLinkage:
     case GlobalValue::ExternalLinkage:
       emitArrayBound(name, GV);
       emitGlobalDirective(name);
@@ -266,8 +268,10 @@ emitFunctionStart(MachineFunction &MF)
   case Function::ExternalLinkage:
     emitGlobalDirective(CurrentFnName);
     break;
-  case Function::LinkOnceLinkage:
-  case Function::WeakLinkage:
+  case Function::LinkOnceAnyLinkage:
+  case Function::LinkOnceODRLinkage:
+  case Function::WeakAnyLinkage:
+  case Function::WeakODRLinkage:
     // TODO Use COMDAT groups for LinkOnceLinkage
     O << TAI->getGlobalDirective() << CurrentFnName << "\n";
     O << TAI->getWeakDefDirective() << CurrentFnName << "\n";
@@ -434,7 +438,8 @@ bool XCoreAsmPrinter::doInitialization(Module &M) {
       switch (I->getLinkage()) {
       default:
         assert(0 && "Unexpected linkage");
-      case Function::ExternalWeakLinkage:
+      case Function::ExternalWeakAnyLinkage:
+      case Function::ExternalWeakODRLinkage:
         ExtWeakSymbols.insert(I);
         // fallthrough
       case Function::ExternalLinkage:
diff --git a/lib/Target/XCore/XCoreTargetAsmInfo.cpp b/lib/Target/XCore/XCoreTargetAsmInfo.cpp
index 847224c766..78eb90c3b1 100644
--- a/lib/Target/XCore/XCoreTargetAsmInfo.cpp
+++ b/lib/Target/XCore/XCoreTargetAsmInfo.cpp
@@ -73,7 +73,7 @@ XCoreTargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV) const {
 
   if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
   {
-    if (!GVar->mayBeOverridden()) {
+    if (!GVar->isWeakForLinker()) {
       switch (Kind) {
       case SectionKind::RODataMergeStr:
         return MergeableStringSection(GVar);
diff --git a/lib/Transforms/IPO/IndMemRemoval.cpp b/lib/Transforms/IPO/IndMemRemoval.cpp
index 6b1f969e44..b55dea2c75 100644
--- a/lib/Transforms/IPO/IndMemRemoval.cpp
+++ b/lib/Transforms/IPO/IndMemRemoval.cpp
@@ -53,7 +53,7 @@ bool IndMemRemPass::runOnModule(Module &M) {
   if (Function* F = M.getFunction("free")) {
     if (F->isDeclaration() && F->arg_size() == 1 && !F->use_empty()) {
       Function* FN = Function::Create(F->getFunctionType(),
-                                      GlobalValue::LinkOnceLinkage,
+                                      GlobalValue::LinkOnceAnyLinkage,
                                       "free_llvm_bounce", &M);
       BasicBlock* bb = BasicBlock::Create("entry",FN);
       Instruction* R = ReturnInst::Create(bb);
@@ -67,7 +67,7 @@ bool IndMemRemPass::runOnModule(Module &M) {
   if (Function* F = M.getFunction("malloc")) {
     if (F->isDeclaration() && F->arg_size() == 1 && !F->use_empty()) {
       Function* FN = Function::Create(F->getFunctionType(), 
-                                      GlobalValue::LinkOnceLinkage, 
+                                      GlobalValue::LinkOnceAnyLinkage,
                                       "malloc_llvm_bounce", &M);
       FN->setDoesNotAlias(0);
       BasicBlock* bb = BasicBlock::Create("entry",FN);
diff --git a/lib/Transforms/Utils/InlineCost.cpp b/lib/Transforms/Utils/InlineCost.cpp
index b9f13d923b..209ba92718 100644
--- a/lib/Transforms/Utils/InlineCost.cpp
+++ b/lib/Transforms/Utils/InlineCost.cpp
@@ -182,12 +182,9 @@ InlineCost InlineCostAnalyzer::getInlineCost(CallSite CS,
 
       // Don't inline functions which can be redefined at link-time to mean
       // something else.
-      // FIXME: We allow link-once linkage since in practice all versions of
-      // the function have the same body (C++ ODR) - but the LLVM definition
-      // of LinkOnceLinkage doesn't require this.
-   if ((Callee->mayBeOverridden() && !Callee->hasLinkOnceLinkage()) ||
-      // Don't inline functions marked noinline.
-      Callee->hasFnAttr(Attribute::NoInline) || NeverInline.count(Callee))
+   if (Callee->mayBeOverridden() ||
+       // Don't inline functions marked noinline.
+       Callee->hasFnAttr(Attribute::NoInline) || NeverInline.count(Callee))
     return llvm::InlineCost::getNever();
 
   // InlineCost - This value measures how good of an inline candidate this call
diff --git a/lib/Transforms/Utils/LowerInvoke.cpp b/lib/Transforms/Utils/LowerInvoke.cpp
index 20cff90643..b0364ecd61 100644
--- a/lib/Transforms/Utils/LowerInvoke.cpp
+++ b/lib/Transforms/Utils/LowerInvoke.cpp
@@ -139,7 +139,7 @@ bool LowerInvoke::doInitialization(Module &M) {
     // already exists.
     if (!(JBListHead = M.getGlobalVariable("llvm.sjljeh.jblist", PtrJBList))) {
       JBListHead = new GlobalVariable(PtrJBList, false,
-                                      GlobalValue::LinkOnceLinkage,
+                                      GlobalValue::LinkOnceAnyLinkage,
                                       Constant::getNullValue(PtrJBList),
                                       "llvm.sjljeh.jblist", &M);
     }
diff --git a/lib/VMCore/AsmWriter.cpp b/lib/VMCore/AsmWriter.cpp
index 239760d2b0..12a8ed6c22 100644
--- a/lib/VMCore/AsmWriter.cpp
+++ b/lib/VMCore/AsmWriter.cpp
@@ -1183,22 +1183,26 @@ void AssemblyWriter::printModule(const Module *M) {
 
 static void PrintLinkage(GlobalValue::LinkageTypes LT, raw_ostream &Out) {
   switch (LT) {
-  case GlobalValue::PrivateLinkage:      Out << "private "; break;
-  case GlobalValue::InternalLinkage:     Out << "internal "; break;
-  case GlobalValue::LinkOnceLinkage:     Out << "linkonce "; break;
-  case GlobalValue::WeakLinkage:         Out << "weak "; 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::PrivateLinkage:     Out << "private "; break;
+  case GlobalValue::InternalLinkage:    Out << "internal "; break;
+  case GlobalValue::LinkOnceAnyLinkage: Out << "linkonce "; break;
+  case GlobalValue::LinkOnceODRLinkage: Out << "linkonce_odr "; break;
+  case GlobalValue::WeakAnyLinkage:     Out << "weak "; break;
+  case GlobalValue::WeakODRLinkage:     Out << "weak_odr "; break;
+  case GlobalValue::CommonAnyLinkage:   Out << "common "; break;
+  case GlobalValue::CommonODRLinkage:   Out << "common_odr "; break;
+  case GlobalValue::AppendingLinkage:   Out << "appending "; break;
+  case GlobalValue::DLLImportLinkage:   Out << "dllimport "; break;
+  case GlobalValue::DLLExportLinkage:   Out << "dllexport "; break;
+  case GlobalValue::ExternalWeakAnyLinkage: Out << "extern_weak "; break;
+  case GlobalValue::ExternalWeakODRLinkage: Out << "extern_weak_odr "; break;
   case GlobalValue::ExternalLinkage: break;
   case GlobalValue::GhostLinkage:
     Out << "GhostLinkage not allowed in AsmWriter!\n";
     abort();
   }
 }
-      
+
 
 static void PrintVisibility(GlobalValue::VisibilityTypes Vis,
                             raw_ostream &Out) {
diff --git a/utils/emacs/llvm-mode.el b/utils/emacs/llvm-mode.el
index 05900992a3..55c56daecd 100644
--- a/utils/emacs/llvm-mode.el
+++ b/utils/emacs/llvm-mode.el
@@ -27,7 +27,7 @@
    ;; Hex constants
    '("\\b0x[0-9A-Fa-f]+\\b" . font-lock-preprocessor-face)
    ;; Keywords
-   '("\\bbegin\\b\\|\\bend\\b\\|\\btrue\\b\\|\\bfalse\\b\\|\\bzeroinitializer\\b\\|\\bdeclare\\b\\|\\bdefine\\b\\|\\bglobal\\b\\|\\bconstant\\b\\|\\bconst\\b\\|\\binternal\\b\\|\\blinkonce\\b\\|\\bweak\\b\\|\\bappending\\b\\|\\buninitialized\\b\\|\\bimplementation\\b\\|\\b\\.\\.\\.\\b\\|\\bnull\\b\\|\\bundef\\b\\|\\bto\\b\\|\\bexcept\\b\\|\\bnot\\b\\|\\btarget\\b\\|\\bendian\\b\\|\\blittle\\b\\|\\bbig\\b\\|\\bpointersize\\b\\|\\bdeplibs\\b\\|\\bvolatile\\b\\|\\bfastcc\\b\\|\\bcoldcc\\b\\|\\bcc\\b" . font-lock-keyword-face)
+   '("\\bbegin\\b\\|\\bend\\b\\|\\btrue\\b\\|\\bfalse\\b\\|\\bzeroinitializer\\b\\|\\bdeclare\\b\\|\\bdefine\\b\\|\\bglobal\\b\\|\\bconstant\\b\\|\\bconst\\b\\|\\binternal\\b\\|\\blinkonce\\b\\|\\blinkonce_odr\\b\\|\\bweak\\b\\|\\bweak_odr\\b\\|\\bappending\\b\\|\\buninitialized\\b\\|\\bimplementation\\b\\|\\b\\.\\.\\.\\b\\|\\bnull\\b\\|\\bundef\\b\\|\\bto\\b\\|\\bexcept\\b\\|\\bnot\\b\\|\\btarget\\b\\|\\bendian\\b\\|\\blittle\\b\\|\\bbig\\b\\|\\bpointersize\\b\\|\\bdeplibs\\b\\|\\bvolatile\\b\\|\\bfastcc\\b\\|\\bcoldcc\\b\\|\\bcc\\b" . font-lock-keyword-face)
    ;; Arithmetic and Logical Operators
    '("\\badd\\b\\|\\bsub\\b\\|\\bmul\\b\\|\\bdiv\\b\\|\\brem\\b\\|\\band\\b\\|\\bor\\b\\|\\bxor\\b\\|\\bset\\(ne\\b\\|\\beq\\b\\|\\blt\\b\\|\\bgt\\b\\|\\ble\\b\\|\\bge\\b\\)" . font-lock-keyword-face)
    ;; Special instructions
diff --git a/utils/llvm.grm b/utils/llvm.grm
index 7025fbde37..641ba01f20 100644
--- a/utils/llvm.grm
+++ b/utils/llvm.grm
@@ -82,15 +82,19 @@ GlobalAssign ::= GlobalName "=" ;
 GVInternalLinkage
   ::= + internal
  | weak
+ | "weak_odr"
  | linkonce
+ | "linkonce_odr"
  | appending
  | dllexport
  | common
+ | "common_odr"
  ;
 
 GVExternalLinkage
   ::= dllimport
  | "extern_weak"
+ | "extern_weak_odr"
  | + external
  ;
 
@@ -105,17 +109,20 @@ FunctionDeclareLinkage
   ::= + _
  | dllimport
  | "extern_weak"
+ | "extern_weak_odr"
  ;
 
 FunctionDefineLinkage
   ::= + _
  | internal
  | linkonce
+ | "linkonce_odr"
  | weak
+ | "weak_odr"
  | dllexport
  ;
 
-AliasLinkage ::= + _ | weak | internal ;
+AliasLinkage ::= + _ | weak | "weak_odr" | internal ;
 
 OptCallingConv ::= + _ |
                  ccc |
diff --git a/utils/vim/llvm.vim b/utils/vim/llvm.vim
index 2edba8e5ae..89787f8056 100644
--- a/utils/vim/llvm.vim
+++ b/utils/vim/llvm.vim
@@ -40,7 +40,8 @@ syn keyword llvmStatement extractvalue insertvalue
 " Keywords.
 syn keyword llvmKeyword define declare global constant
 syn keyword llvmKeyword internal external
-syn keyword llvmKeyword linkonce weak appending common extern_weak
+syn keyword llvmKeyword linkonce linkonce_odr weak weak_odr appending
+syn keyword llvmKeyword common common_odr extern_weak extern_weak_odr
 syn keyword llvmKeyword thread_local dllimport dllexport
 syn keyword llvmKeyword hidden protected default
 syn keyword llvmKeyword except deplibs