Create the new linker type "linker_private_weak_def_auto".

It's similar to "linker_private_weak", but it's known that the address of the
object is not taken. For instance, functions that had an inline definition, but
the compiler decided not to inline it. Note, unlike linker_private and
linker_private_weak, linker_private_weak_def_auto may have only default
visibility.  The symbols are removed by the linker from the final linked image
(executable or dynamic library).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111684 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/docs/LangRef.html b/docs/LangRef.html
index 7422d72a59d367c938df8e6320c1a804b5f010ea..b8897fd5053d77917d9725cd3e96cd7d621d2a59 100644 (file)
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -25,6 +25,7 @@
           <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
           <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
           <li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
+          <li><a href="#linkage_linker_private_weak_def_auto">'<tt>linker_private_weak_def_auto</tt>' Linkage</a></li>
           <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
           <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
           <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
@@ -557,6 +558,15 @@ define i32 @main() {   <i>; i32()* </i>&nbsp;
       linker. The symbols are removed by the linker from the final linked image
       (executable or dynamic library).</dd>
 
+  <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
+  <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
+      of the object is not taken. For instance, functions that had an inline
+      definition, but the compiler decided not to inline it. Note,
+      unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
+      <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
+      visibility.  The symbols are removed by the linker from the final linked
+      image (executable or dynamic library).</dd>
+
   <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
   <dd>Similar to private, but the value shows as a local symbol
       (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This

diff --git a/include/llvm-c/Core.h b/include/llvm-c/Core.h
index 665dd0447c98a391a43752fbd5c8cdbce06e45bc..20c63832112b329936974e26518e65bd0eb85fe3 100644 (file)
--- a/include/llvm-c/Core.h
+++ b/include/llvm-c/Core.h
@@ -227,7 +227,9 @@ typedef enum {
   LLVMGhostLinkage,       /**< Obsolete */
   LLVMCommonLinkage,      /**< Tentative definitions */
   LLVMLinkerPrivateLinkage, /**< Like Private, but linker removes. */
-  LLVMLinkerPrivateWeakLinkage /**< Like LinkerPrivate, but is weak. */
+  LLVMLinkerPrivateWeakLinkage, /**< Like LinkerPrivate, but is weak. */
+  LLVMLinkerPrivateWeakDefAutoLinkage /**< Like LinkerPrivateWeak, but possibly
+                                           hidden. */
 } LLVMLinkage;
 
 typedef enum {

diff --git a/include/llvm/GlobalValue.h b/include/llvm/GlobalValue.h
index f4bee85b45f001f160de8b11b212c6a9a1766b28..62e84f83351049631fbee6db411562b027872d92 100644 (file)
--- a/include/llvm/GlobalValue.h
+++ b/include/llvm/GlobalValue.h
@@ -41,6 +41,8 @@ public:
     PrivateLinkage,     ///< Like Internal, but omit from symbol table.
     LinkerPrivateLinkage, ///< Like Private, but linker removes.
     LinkerPrivateWeakLinkage, ///< Like LinkerPrivate, but weak.
+    LinkerPrivateWeakDefAutoLinkage, ///< Like LinkerPrivateWeak, but possibly
+                                     ///  hidden.
     DLLImportLinkage,   ///< Function to be imported from DLL
     DLLExportLinkage,   ///< Function to be accessible from DLL.
     ExternalWeakLinkage,///< ExternalWeak linkage description.
@@ -137,9 +139,13 @@ public:
   static bool isLinkerPrivateWeakLinkage(LinkageTypes Linkage) {
     return Linkage == LinkerPrivateWeakLinkage;
   }
+  static bool isLinkerPrivateWeakDefAutoLinkage(LinkageTypes Linkage) {
+    return Linkage == LinkerPrivateWeakDefAutoLinkage;
+  }
   static bool isLocalLinkage(LinkageTypes Linkage) {
     return isInternalLinkage(Linkage) || isPrivateLinkage(Linkage) ||
-      isLinkerPrivateLinkage(Linkage) || isLinkerPrivateWeakLinkage(Linkage);
+      isLinkerPrivateLinkage(Linkage) || isLinkerPrivateWeakLinkage(Linkage) ||
+      isLinkerPrivateWeakDefAutoLinkage(Linkage);
   }
   static bool isDLLImportLinkage(LinkageTypes Linkage) {
     return Linkage == DLLImportLinkage;
@@ -158,24 +164,26 @@ public:
   /// 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.
   static bool mayBeOverridden(LinkageTypes Linkage) {
-    return (Linkage == WeakAnyLinkage ||
-            Linkage == LinkOnceAnyLinkage ||
-            Linkage == CommonLinkage ||
-            Linkage == ExternalWeakLinkage ||
-            Linkage == LinkerPrivateWeakLinkage);
+    return Linkage == WeakAnyLinkage ||
+           Linkage == LinkOnceAnyLinkage ||
+           Linkage == CommonLinkage ||
+           Linkage == ExternalWeakLinkage ||
+           Linkage == LinkerPrivateWeakLinkage ||
+           Linkage == LinkerPrivateWeakDefAutoLinkage;
   }
 
   /// isWeakForLinker - Whether the definition of this global may be replaced at
   /// link time.
   static bool isWeakForLinker(LinkageTypes Linkage)  {
-    return (Linkage == AvailableExternallyLinkage ||
-            Linkage == WeakAnyLinkage ||
-            Linkage == WeakODRLinkage ||
-            Linkage == LinkOnceAnyLinkage ||
-            Linkage == LinkOnceODRLinkage ||
-            Linkage == CommonLinkage ||
-            Linkage == ExternalWeakLinkage ||
-            Linkage == LinkerPrivateWeakLinkage);
+    return Linkage == AvailableExternallyLinkage ||
+           Linkage == WeakAnyLinkage ||
+           Linkage == WeakODRLinkage ||
+           Linkage == LinkOnceAnyLinkage ||
+           Linkage == LinkOnceODRLinkage ||
+           Linkage == CommonLinkage ||
+           Linkage == ExternalWeakLinkage ||
+           Linkage == LinkerPrivateWeakLinkage ||
+           Linkage == LinkerPrivateWeakDefAutoLinkage;
   }
 
   bool hasExternalLinkage() const { return isExternalLinkage(Linkage); }
@@ -195,6 +203,9 @@ public:
   bool hasLinkerPrivateWeakLinkage() const {
     return isLinkerPrivateWeakLinkage(Linkage);
   }
+  bool hasLinkerPrivateWeakDefAutoLinkage() const {
+    return isLinkerPrivateWeakDefAutoLinkage(Linkage);
+  }
   bool hasLocalLinkage() const { return isLocalLinkage(Linkage); }
   bool hasDLLImportLinkage() const { return isDLLImportLinkage(Linkage); }
   bool hasDLLExportLinkage() const { return isDLLExportLinkage(Linkage); }

diff --git a/lib/AsmParser/LLLexer.cpp b/lib/AsmParser/LLLexer.cpp
index f4c0e50fd94dffc148f50038aa05577f723bc8aa..90696b950fea123e356d771912551c68770f180f 100644 (file)
--- a/lib/AsmParser/LLLexer.cpp
+++ b/lib/AsmParser/LLLexer.cpp
@@ -493,6 +493,7 @@ lltok::Kind LLLexer::LexIdentifier() {
   KEYWORD(private);
   KEYWORD(linker_private);
   KEYWORD(linker_private_weak);
+  KEYWORD(linker_private_weak_def_auto);
   KEYWORD(internal);
   KEYWORD(available_externally);
   KEYWORD(linkonce);

diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index dc545fff2daf51f622cd73b22e94961dc5b971d2..0c5e04992f053e393d7465a1b4049d3a0229e7ce 100644 (file)
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -199,6 +199,7 @@ bool LLParser::ParseTopLevelEntities() {
     case lltok::kw_private:             // OptionalLinkage
     case lltok::kw_linker_private:      // OptionalLinkage
     case lltok::kw_linker_private_weak: // OptionalLinkage
+    case lltok::kw_linker_private_weak_def_auto: // OptionalLinkage
     case lltok::kw_internal:            // OptionalLinkage
     case lltok::kw_weak:                // OptionalLinkage
     case lltok::kw_weak_odr:            // OptionalLinkage
@@ -623,7 +624,8 @@ bool LLParser::ParseAlias(const std::string &Name, LocTy NameLoc,
       Linkage != GlobalValue::InternalLinkage &&
       Linkage != GlobalValue::PrivateLinkage &&
       Linkage != GlobalValue::LinkerPrivateLinkage &&
-      Linkage != GlobalValue::LinkerPrivateWeakLinkage)
+      Linkage != GlobalValue::LinkerPrivateWeakLinkage &&
+      Linkage != GlobalValue::LinkerPrivateWeakDefAutoLinkage)
     return Error(LinkageLoc, "invalid linkage type for alias");
 
   Constant *Aliasee;
@@ -1008,6 +1010,7 @@ bool LLParser::ParseOptionalAttrs(unsigned &Attrs, unsigned AttrKind) {
 ///   ::= 'private'
 ///   ::= 'linker_private'
 ///   ::= 'linker_private_weak'
+///   ::= 'linker_private_weak_def_auto'
 ///   ::= 'internal'
 ///   ::= 'weak'
 ///   ::= 'weak_odr'
@@ -1029,6 +1032,9 @@ bool LLParser::ParseOptionalLinkage(unsigned &Res, bool &HasLinkage) {
   case lltok::kw_linker_private_weak:
     Res = GlobalValue::LinkerPrivateWeakLinkage;
     break;
+  case lltok::kw_linker_private_weak_def_auto:
+    Res = GlobalValue::LinkerPrivateWeakDefAutoLinkage;
+    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;
@@ -2718,6 +2724,7 @@ bool LLParser::ParseFunctionHeader(Function *&Fn, bool isDefine) {
   case GlobalValue::PrivateLinkage:
   case GlobalValue::LinkerPrivateLinkage:
   case GlobalValue::LinkerPrivateWeakLinkage:
+  case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
   case GlobalValue::InternalLinkage:
   case GlobalValue::AvailableExternallyLinkage:
   case GlobalValue::LinkOnceAnyLinkage:

diff --git a/lib/AsmParser/LLToken.h b/lib/AsmParser/LLToken.h
index 2703134ec1a96cf078fd079ed74cb4360b2d2372..e266db994e92e5a1cf6250056fe64cbe067ab8ba 100644 (file)
--- a/lib/AsmParser/LLToken.h
+++ b/lib/AsmParser/LLToken.h
@@ -37,7 +37,8 @@ namespace lltok {
     kw_declare, kw_define,
     kw_global,  kw_constant,
 
-    kw_private, kw_linker_private, kw_linker_private_weak, kw_internal,
+    kw_private, kw_linker_private, kw_linker_private_weak,
+    kw_linker_private_weak_def_auto, kw_internal,
     kw_linkonce, kw_linkonce_odr, kw_weak, kw_weak_odr, kw_appending,
     kw_dllimport, kw_dllexport, kw_common, kw_available_externally,
     kw_default, kw_hidden, kw_protected,

diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 2010468824c1ac699628dddd153c548dd20b867a..2e86abfbc07539b83182758af51cd1b9c0c1b786 100644 (file)
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -77,6 +77,7 @@ static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
   case 12: return GlobalValue::AvailableExternallyLinkage;
   case 13: return GlobalValue::LinkerPrivateLinkage;
   case 14: return GlobalValue::LinkerPrivateWeakLinkage;
+  case 15: return GlobalValue::LinkerPrivateWeakDefAutoLinkage;
   }
 }
 

diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 776c2d4495c167110fb6a8bbd71410bdc3e875d2..390e4827feb8764867ab610be4d774bd2bf1da9d 100644 (file)
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -299,21 +299,22 @@ static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 static unsigned getEncodedLinkage(const GlobalValue *GV) {
   switch (GV->getLinkage()) {
   default: llvm_unreachable("Invalid linkage!");
-  case GlobalValue::ExternalLinkage:            return 0;
-  case GlobalValue::WeakAnyLinkage:             return 1;
-  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;
-  case GlobalValue::WeakODRLinkage:             return 10;
-  case GlobalValue::LinkOnceODRLinkage:         return 11;
-  case GlobalValue::AvailableExternallyLinkage: return 12;
-  case GlobalValue::LinkerPrivateLinkage:       return 13;
-  case GlobalValue::LinkerPrivateWeakLinkage:   return 14;
+  case GlobalValue::ExternalLinkage:                 return 0;
+  case GlobalValue::WeakAnyLinkage:                  return 1;
+  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;
+  case GlobalValue::WeakODRLinkage:                  return 10;
+  case GlobalValue::LinkOnceODRLinkage:              return 11;
+  case GlobalValue::AvailableExternallyLinkage:      return 12;
+  case GlobalValue::LinkerPrivateLinkage:            return 13;
+  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
+  case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
   }
 }
 

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 25b8d990618406505872b81256a5aa60f764712c..fa0b97fab63210b2be3314d5a1f2179976011d98 100644 (file)
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -200,11 +200,17 @@ void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
   case GlobalValue::WeakAnyLinkage:
   case GlobalValue::WeakODRLinkage:
   case GlobalValue::LinkerPrivateWeakLinkage:
+  case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
     if (MAI->getWeakDefDirective() != 0) {
       // .globl _foo
       OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
-      // .weak_definition _foo
-      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
+
+      if ((GlobalValue::LinkageTypes)Linkage !=
+          GlobalValue::LinkerPrivateWeakDefAutoLinkage)
+        // .weak_definition _foo
+        OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
+      else
+        OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
     } else if (MAI->getLinkOnceDirective() != 0) {
       // .globl _foo
       OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);

diff --git a/lib/Target/CppBackend/CPPBackend.cpp b/lib/Target/CppBackend/CPPBackend.cpp
index 3e21cd1de447456e8e704d5aded340618b18e988..f08559f6e9f2efff68d5d615b726897b06b280a9 100644 (file)
--- a/lib/Target/CppBackend/CPPBackend.cpp
+++ b/lib/Target/CppBackend/CPPBackend.cpp
@@ -288,6 +288,8 @@ void CppWriter::printLinkageType(GlobalValue::LinkageTypes LT) {
     Out << "GlobalValue::LinkerPrivateLinkage"; break;
   case GlobalValue::LinkerPrivateWeakLinkage:
     Out << "GlobalValue::LinkerPrivateWeakLinkage"; break;
+  case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
+    Out << "GlobalValue::LinkerPrivateWeakDefAutoLinkage"; break;
   case GlobalValue::AvailableExternallyLinkage:
     Out << "GlobalValue::AvailableExternallyLinkage "; break;
   case GlobalValue::LinkOnceAnyLinkage:

diff --git a/lib/Target/Mangler.cpp b/lib/Target/Mangler.cpp
index 2037a9114559e3d14c90713d76b6d44c6006e946..49efe75d79d8f02e51df9aad34c7af69042d3cb0 100644 (file)
--- a/lib/Target/Mangler.cpp
+++ b/lib/Target/Mangler.cpp
@@ -180,7 +180,8 @@ void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
   ManglerPrefixTy PrefixTy = Mangler::Default;
   if (GV->hasPrivateLinkage() || isImplicitlyPrivate)
     PrefixTy = Mangler::Private;
-  else if (GV->hasLinkerPrivateLinkage() || GV->hasLinkerPrivateWeakLinkage())
+  else if (GV->hasLinkerPrivateLinkage() || GV->hasLinkerPrivateWeakLinkage() ||
+           GV->hasLinkerPrivateWeakDefAutoLinkage())
     PrefixTy = Mangler::LinkerPrivate;
   
   // If this global has a name, handle it simply.

diff --git a/lib/VMCore/AsmWriter.cpp b/lib/VMCore/AsmWriter.cpp
index c925a7e3391e9ad7e9ea6d6f40129804df3a5c8d..c7f27c62639cad1519d9d09c1e5a55261e2331bf 100644 (file)
--- a/lib/VMCore/AsmWriter.cpp
+++ b/lib/VMCore/AsmWriter.cpp
@@ -1435,6 +1435,9 @@ static void PrintLinkage(GlobalValue::LinkageTypes LT,
   case GlobalValue::LinkerPrivateWeakLinkage:
     Out << "linker_private_weak ";
     break;
+  case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
+    Out << "linker_private_weak_def_auto ";
+    break;
   case GlobalValue::InternalLinkage:      Out << "internal ";       break;
   case GlobalValue::LinkOnceAnyLinkage:   Out << "linkonce ";       break;
   case GlobalValue::LinkOnceODRLinkage:   Out << "linkonce_odr ";   break;

diff --git a/lib/VMCore/Core.cpp b/lib/VMCore/Core.cpp
index f458051c31c70950ac55828286ef8a732362edef..e884404d8acd0faf78ef1e84b3e90df2153ada38 100644 (file)
--- a/lib/VMCore/Core.cpp
+++ b/lib/VMCore/Core.cpp
@@ -1069,6 +1069,8 @@ LLVMLinkage LLVMGetLinkage(LLVMValueRef Global) {
     return LLVMLinkerPrivateLinkage;
   case GlobalValue::LinkerPrivateWeakLinkage:
     return LLVMLinkerPrivateWeakLinkage;
+  case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
+    return LLVMLinkerPrivateWeakDefAutoLinkage;
   case GlobalValue::DLLImportLinkage:
     return LLVMDLLImportLinkage;
   case GlobalValue::DLLExportLinkage:
@@ -1122,6 +1124,9 @@ void LLVMSetLinkage(LLVMValueRef Global, LLVMLinkage Linkage) {
   case LLVMLinkerPrivateWeakLinkage:
     GV->setLinkage(GlobalValue::LinkerPrivateWeakLinkage);
     break;
+  case LLVMLinkerPrivateWeakDefAutoLinkage:
+    GV->setLinkage(GlobalValue::LinkerPrivateWeakDefAutoLinkage);
+    break;
   case LLVMDLLImportLinkage:
     GV->setLinkage(GlobalValue::DLLImportLinkage);
     break;

diff --git a/lib/VMCore/Verifier.cpp b/lib/VMCore/Verifier.cpp
index 8ff1551424352faec241fe43f68cb887f78b80d3..a3f1510887d5fa3a336ec4ab423f18ee13c2c1e9 100644 (file)
--- a/lib/VMCore/Verifier.cpp
+++ b/lib/VMCore/Verifier.cpp
@@ -446,6 +446,10 @@ void Verifier::visitGlobalValue(GlobalValue &GV) {
     Assert1(GVar && GVar->getType()->getElementType()->isArrayTy(),
             "Only global arrays can have appending linkage!", GVar);
   }
+
+  Assert1(!GV.hasLinkerPrivateWeakDefAutoLinkage() || GV.hasDefaultVisibility(),
+          "linker_private_weak_def_auto can only have default visibility!",
+          &GV);
 }
 
 void Verifier::visitGlobalVariable(GlobalVariable &GV) {

diff --git a/test/Feature/linker_private_linkages.ll b/test/Feature/linker_private_linkages.ll
index 19bcbb40aa017a965fbf8dfb5df62c14dc73a213..f9f2908756451f7898e7725467cefcf368e1916b 100644 (file)
--- a/test/Feature/linker_private_linkages.ll
+++ b/test/Feature/linker_private_linkages.ll
@@ -4,3 +4,4 @@
 
 @foo = linker_private hidden global i32 0
 @bar = linker_private_weak hidden global i32 0
+@qux = linker_private_weak_def_auto global i32 0