For PR780:

1. Fix the macros in IncludeFile.h to put everything in the llvm namespace
2. Replace the previous explicit mechanism in all the .h and .cpp files
   with the macros in IncludeFile.h
This gets us a consistent mechanism throughout LLVM for ensuring linkage.
Next step is to make sure its used in enough places.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28715 91177308-0d34-0410-b5e6-96231b3b80d8

19 files changed, 57 insertions, 78 deletions

diff --git a/include/llvm/Analysis/AliasAnalysis.h b/include/llvm/Analysis/AliasAnalysis.h
index d715e0880b..2fff77420a 100644
--- a/include/llvm/Analysis/AliasAnalysis.h
+++ b/include/llvm/Analysis/AliasAnalysis.h
@@ -318,14 +318,13 @@ public:
   }
 };
 
+} // End llvm namespace
+
 // Because of the way .a files work, we must force the BasicAA implementation to
 // be pulled in if the AliasAnalysis header is included.  Otherwise we run
 // the risk of AliasAnalysis being used, but the default implementation not
 // being linked into the tool that uses it.
-//
-extern int BasicAAStub;
-static IncludeFile HDR_INCLUDE_BASICAA_CPP(&BasicAAStub);
-
-} // End llvm namespace
+FORCE_DEFINING_FILE_TO_BE_LINKED(AliasAnalysis)
+FORCE_DEFINING_FILE_TO_BE_LINKED(BasicAliasAnalysis)
 
 #endif
diff --git a/include/llvm/Analysis/CallGraph.h b/include/llvm/Analysis/CallGraph.h
index e51a3c7fb1..94cea10048 100644
--- a/include/llvm/Analysis/CallGraph.h
+++ b/include/llvm/Analysis/CallGraph.h
@@ -287,13 +287,9 @@ template<> struct GraphTraits<const CallGraph*> :
   static nodes_iterator nodes_end  (const CallGraph *CG) { return CG->end(); }
 };
 
-// Make sure that any clients of this file link in CallGraph.cpp
-static IncludeFile
-CALLGRAPH_INCLUDE_FILE(&CallGraph::stub);
-
-extern int BasicCallGraphStub;
-static IncludeFile HDR_INCLUDE_CALLGRAPH_CPP(&BasicCallGraphStub);
-
 } // End llvm namespace
 
+// Make sure that any clients of this file link in CallGraph.cpp
+FORCE_DEFINING_FILE_TO_BE_LINKED(CallGraph)
+
 #endif
diff --git a/include/llvm/Analysis/Dominators.h b/include/llvm/Analysis/Dominators.h
index 224e529915..31b8562f2c 100644
--- a/include/llvm/Analysis/Dominators.h
+++ b/include/llvm/Analysis/Dominators.h
@@ -652,9 +652,9 @@ private:
 };
 
 
-// Make sure that any clients of this file link in Dominators.cpp
-static IncludeFile
-DOMINATORS_INCLUDE_FILE(&DominatorSet::stub);
 } // End llvm namespace
 
+// Make sure that any clients of this file link in Dominators.cpp
+FORCE_DEFINING_FILE_TO_BE_LINKED(DominatorSet)
+
 #endif
diff --git a/include/llvm/Analysis/FindUsedTypes.h b/include/llvm/Analysis/FindUsedTypes.h
index e16fe9d7c3..fbf41de7cb 100644
--- a/include/llvm/Analysis/FindUsedTypes.h
+++ b/include/llvm/Analysis/FindUsedTypes.h
@@ -53,15 +53,11 @@ public:
   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
     AU.setPreservesAll();
   }
-
-  // stub - dummy function, just ignore it
-  static int stub;
 };
 
-// Make sure that any clients of this file link in PostDominators.cpp
-static IncludeFile
-FIND_USED_TYPES_INCLUDE_FILE(&FindUsedTypes::stub);
-
 } // End llvm namespace
 
+// Make sure that any clients of this file link in PostDominators.cpp
+FORCE_DEFINING_FILE_TO_BE_LINKED(FindUsedTypes)
+
 #endif
diff --git a/include/llvm/Analysis/LoopInfo.h b/include/llvm/Analysis/LoopInfo.h
index 065ce31d8b..06b007cf3f 100644
--- a/include/llvm/Analysis/LoopInfo.h
+++ b/include/llvm/Analysis/LoopInfo.h
@@ -295,7 +295,6 @@ public:
   /// BasicBlocks to loops.
   void removeBlock(BasicBlock *BB);
 
-  static int stub;  // Noop
 private:
   void Calculate(ETForest &EF);
   Loop *ConsiderForLoop(BasicBlock *BB, ETForest &EF);
@@ -304,10 +303,6 @@ private:
 };
 
 
-// Make sure that any clients of this file link in LoopInfo.cpp
-static IncludeFile
-LOOP_INFO_INCLUDE_FILE(&LoopInfo::stub);
-
 // Allow clients to walk the list of nested loops...
 template <> struct GraphTraits<const Loop*> {
   typedef const Loop NodeType;
@@ -337,4 +332,7 @@ template <> struct GraphTraits<Loop*> {
 
 } // End llvm namespace
 
+// Make sure that any clients of this file link in LoopInfo.cpp
+FORCE_DEFINING_FILE_TO_BE_LINKED(LoopInfo)
+
 #endif
diff --git a/include/llvm/Analysis/PostDominators.h b/include/llvm/Analysis/PostDominators.h
index 1436be3037..4d8d140373 100644
--- a/include/llvm/Analysis/PostDominators.h
+++ b/include/llvm/Analysis/PostDominators.h
@@ -128,18 +128,14 @@ struct PostDominanceFrontier : public DominanceFrontierBase {
     AU.addRequired<PostDominatorTree>();
   }
 
-  // stub - dummy function, just ignore it
-  static int stub;
-
 private:
   const DomSetType &calculate(const PostDominatorTree &DT,
                               const DominatorTree::Node *Node);
 };
 
-// Make sure that any clients of this file link in PostDominators.cpp
-static IncludeFile
-POST_DOMINATOR_INCLUDE_FILE(&PostDominanceFrontier::stub);
-
 } // End llvm namespace
 
+// Make sure that any clients of this file link in PostDominators.cpp
+FORCE_DEFINING_FILE_TO_BE_LINKED(PostDominanceFrontier)
+
 #endif
diff --git a/include/llvm/Analysis/ValueNumbering.h b/include/llvm/Analysis/ValueNumbering.h
index 2fc949766e..f708f48382 100644
--- a/include/llvm/Analysis/ValueNumbering.h
+++ b/include/llvm/Analysis/ValueNumbering.h
@@ -65,10 +65,9 @@ struct ValueNumbering {
   }
 };
 
-extern int BasicValueNumberingStub;
-static IncludeFile
-HDR_INCLUDE_VALUENUMBERING_CPP(&BasicValueNumberingStub);
-
 } // End llvm namespace
 
+// Force any file including this header to get the implementation as well
+FORCE_DEFINING_FILE_TO_BE_LINKED(BasicValueNumbering)
+
 #endif
diff --git a/include/llvm/IntrinsicInst.h b/include/llvm/IntrinsicInst.h
index fbc3968f26..5b784fc2b9 100644
--- a/include/llvm/IntrinsicInst.h
+++ b/include/llvm/IntrinsicInst.h
@@ -314,11 +314,10 @@ namespace llvm {
     }
   };
 
-// A hack to ensure that the IntrinsicInst.cpp file gets added as a dependency
-// of any file that 
-extern char LinkIntrinsicInstStub;
-static IncludeFile LinkIntrinsicInst(&LinkIntrinsicInstStub);
-
 }
 
+// Ensure that the IntrinsicInst.cpp file gets added as a dependency of any 
+// file that includes this header
+FORCE_DEFINING_FILE_TO_BE_LINKED(IntrinsicInst)
+
 #endif
diff --git a/include/llvm/Support/IncludeFile.h b/include/llvm/Support/IncludeFile.h
index 8e96f7571f..798c6b454f 100644
--- a/include/llvm/Support/IncludeFile.h
+++ b/include/llvm/Support/IncludeFile.h
@@ -27,13 +27,15 @@
 /// And, foo.cp would use:<br/>
 /// <tt>DEFINING_FILE_FOR(foo)</tt><br/>
 #define FORCE_DEFINING_FILE_TO_BE_LINKED(name) \
-  extern char name ## LinkVar; \
-  static IncludeFile name ## LinkObj ( &name ## LinkVar )
+  namespace llvm { \
+    extern char name ## LinkVar; \
+    static IncludeFile name ## LinkObj ( &name ## LinkVar ); \
+  } 
 
 /// This macro is the counterpart to FORCE_DEFINING_FILE_TO_BE_LINKED. It should
 /// be used in a .cpp file to define the name referenced in a header file that
 /// will cause linkage of the .cpp file. It should only be used at extern level.
-#define DEFINING_FILE_FOR(name) char name
+#define DEFINING_FILE_FOR(name) namespace llvm { char name ## LinkVar; }
 
 namespace llvm {
 
diff --git a/include/llvm/System/IncludeFile.h b/include/llvm/System/IncludeFile.h
index 8e96f7571f..798c6b454f 100644
--- a/include/llvm/System/IncludeFile.h
+++ b/include/llvm/System/IncludeFile.h
@@ -27,13 +27,15 @@
 /// And, foo.cp would use:<br/>
 /// <tt>DEFINING_FILE_FOR(foo)</tt><br/>
 #define FORCE_DEFINING_FILE_TO_BE_LINKED(name) \
-  extern char name ## LinkVar; \
-  static IncludeFile name ## LinkObj ( &name ## LinkVar )
+  namespace llvm { \
+    extern char name ## LinkVar; \
+    static IncludeFile name ## LinkObj ( &name ## LinkVar ); \
+  } 
 
 /// This macro is the counterpart to FORCE_DEFINING_FILE_TO_BE_LINKED. It should
 /// be used in a .cpp file to define the name referenced in a header file that
 /// will cause linkage of the .cpp file. It should only be used at extern level.
-#define DEFINING_FILE_FOR(name) char name
+#define DEFINING_FILE_FOR(name) namespace llvm { char name ## LinkVar; }
 
 namespace llvm {
 
diff --git a/lib/Analysis/AliasAnalysis.cpp b/lib/Analysis/AliasAnalysis.cpp
index 2abcbde74e..1843cd41d4 100644
--- a/lib/Analysis/AliasAnalysis.cpp
+++ b/lib/Analysis/AliasAnalysis.cpp
@@ -188,8 +188,4 @@ bool AliasAnalysis::canInstructionRangeModify(const Instruction &I1,
 // be pulled in if the AliasAnalysis classes are pulled in.  Otherwise we run
 // the risk of AliasAnalysis being used, but the default implementation not
 // being linked into the tool that uses it.
-//
-namespace llvm {
-  extern int BasicAAStub;
-}
-static IncludeFile INCLUDE_BASICAA_CPP((void*)&BasicAAStub);
+DEFINING_FILE_FOR(AliasAnalysis)
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 3cda92e49f..fa4a029648 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -26,9 +26,6 @@
 #include <algorithm>
 using namespace llvm;
 
-// Make sure that anything that uses AliasAnalysis pulls in this file...
-int llvm::BasicAAStub;
-
 namespace {
   /// NoAA - This class implements the -no-aa pass, which always returns "I
   /// don't know" for alias queries.  NoAA is unlike other alias analysis
@@ -846,3 +843,6 @@ BasicAliasAnalysis::getModRefBehavior(Function *F, CallSite CS,
 
   return UnknownModRefBehavior;
 }
+
+// Make sure that anything that uses AliasAnalysis pulls in this file...
+DEFINING_FILE_FOR(BasicAliasAnalysis)
diff --git a/lib/Analysis/IPA/CallGraph.cpp b/lib/Analysis/IPA/CallGraph.cpp
index f8846d390a..78bb735ffa 100644
--- a/lib/Analysis/IPA/CallGraph.cpp
+++ b/lib/Analysis/IPA/CallGraph.cpp
@@ -19,8 +19,6 @@
 #include <iostream>
 using namespace llvm;
 
-int llvm::BasicCallGraphStub;
-
 static bool isOnlyADirectCall(Function *F, CallSite CS) {
   if (!CS.getInstruction()) return false;
   for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); I != E; ++I)
@@ -256,10 +254,6 @@ CallGraphNode *CallGraph::getOrInsertFunction(const Function *F) {
   return CGN = new CallGraphNode(const_cast<Function*>(F));
 }
 
-
-
-int CallGraph::stub; // to ensure linkage of this file.
-
 void CallGraphNode::print(std::ostream &OS) const {
   if (Function *F = getFunction())
     OS << "Call graph node for function: '" << F->getName() <<"'\n";
@@ -297,3 +291,6 @@ void CallGraphNode::removeAnyCallEdgeTo(CallGraphNode *Callee) {
       --i; --e;
     }
 }
+
+// Enuse that users of CallGraph.h also link with this file
+DEFINING_FILE_FOR(CallGraph)
diff --git a/lib/Analysis/IPA/FindUsedTypes.cpp b/lib/Analysis/IPA/FindUsedTypes.cpp
index f7efc7d3a4..725cec4c01 100644
--- a/lib/Analysis/IPA/FindUsedTypes.cpp
+++ b/lib/Analysis/IPA/FindUsedTypes.cpp
@@ -24,9 +24,6 @@ using namespace llvm;
 static RegisterAnalysis<FindUsedTypes>
 X("printusedtypes", "Find Used Types");
 
-// stub to help linkage
-int FindUsedTypes::stub; // to ensure linkage of this file
-
 // IncorporateType - Incorporate one type and all of its subtypes into the
 // collection of used types.
 //
@@ -104,3 +101,6 @@ void FindUsedTypes::print(std::ostream &o, const Module *M) const {
            E = UsedTypes.end(); I != E; ++I)
       o << "  " << **I << "\n";
 }
+
+// Ensure that this file gets linked in when FindUsedTypes.h is used.
+DEFINING_FILE_FOR(FindUsedTypes)
diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp
index f2ef17682f..c7ce58ef91 100644
--- a/lib/Analysis/LoopInfo.cpp
+++ b/lib/Analysis/LoopInfo.cpp
@@ -86,8 +86,6 @@ void Loop::dump() const {
 //===----------------------------------------------------------------------===//
 // LoopInfo implementation
 //
-int LoopInfo::stub;
-
 bool LoopInfo::runOnFunction(Function &) {
   releaseMemory();
   Calculate(getAnalysis<ETForest>());    // Update
@@ -557,3 +555,6 @@ Loop *Loop::removeChildLoop(iterator I) {
 void Loop::removeBlockFromLoop(BasicBlock *BB) {
   RemoveFromVector(Blocks, BB);
 }
+
+// Ensure this file gets linked when LoopInfo.h is used.
+DEFINING_FILE_FOR(LoopInfo)
diff --git a/lib/Analysis/PostDominators.cpp b/lib/Analysis/PostDominators.cpp
index 611ea60a67..e195d7a4c7 100644
--- a/lib/Analysis/PostDominators.cpp
+++ b/lib/Analysis/PostDominators.cpp
@@ -359,6 +359,5 @@ PostDominanceFrontier::calculate(const PostDominatorTree &DT,
   return S;
 }
 
-// stub - a dummy function to make linking work ok.
-int PostDominanceFrontier::stub;
-
+// Ensure that this .cpp file gets linked when PostDominators.h is used.
+DEFINING_FILE_FOR(PostDominanceFrontier)
diff --git a/lib/Analysis/ValueNumbering.cpp b/lib/Analysis/ValueNumbering.cpp
index 0648222454..c534bba4dc 100644
--- a/lib/Analysis/ValueNumbering.cpp
+++ b/lib/Analysis/ValueNumbering.cpp
@@ -239,4 +239,5 @@ void BVNImpl::handleTernaryInst(Instruction &I) {
 }
 
 
-int llvm::BasicValueNumberingStub; // to ensure linkage of this file
+// Ensure that users of ValueNumbering.h will link with this file
+DEFINING_FILE_FOR(BasicValueNumbering)
diff --git a/lib/VMCore/Dominators.cpp b/lib/VMCore/Dominators.cpp
index a0a6d253b2..35c847f7d6 100644
--- a/lib/VMCore/Dominators.cpp
+++ b/lib/VMCore/Dominators.cpp
@@ -304,8 +304,6 @@ bool DominatorSet::runOnFunction(Function &F) {
   return false;
 }
 
-int DominatorSet::stub;
-
 namespace llvm {
 static std::ostream &operator<<(std::ostream &o,
                                 const std::set<BasicBlock*> &BBs) {
@@ -933,3 +931,5 @@ void ETForestBase::print(std::ostream &o, const Module *) const {
   }
   o << "\n";
 }
+
+DEFINING_FILE_FOR(DominatorSet)
diff --git a/lib/VMCore/IntrinsicInst.cpp b/lib/VMCore/IntrinsicInst.cpp
index b4395e1cd3..598a99f18f 100644
--- a/lib/VMCore/IntrinsicInst.cpp
+++ b/lib/VMCore/IntrinsicInst.cpp
@@ -71,7 +71,5 @@ std::string DbgStopPointInst::getDirectory() const {
 }
 
 //===----------------------------------------------------------------------===//
-/// LinkIntrinsicInstStub -- This is a hack to make sure that programs that
-/// #include IntrinsicInst.h also link this file. See Support/IncludeFile.h
-/// for further details.
-char llvm::LinkIntrinsicInstStub;
+/// Ensure that users of IntrinsicInst.h will link with this module.
+DEFINING_FILE_FOR(IntrinsicInst)