Define metadata interfaces for describing a static data member

of a class. Emit static data member declarations and definitions
through correctly.

Part of PR14471.

Patch by Paul Robinson!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172590 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/DIBuilder.h

@@ -172,6 +172,19 @@ namespace llvm {
                             uint64_t AlignInBits, uint64_t OffsetInBits, 
                             unsigned Flags, DIType Ty);
 
+    /// createStaticMemberType - Create debugging information entry for a
+    /// C++ static data member.
+    /// @param Scope      Member scope.
+    /// @param Name       Member name.
+    /// @param File       File where this member is declared.
+    /// @param LineNo     Line number.
+    /// @param Ty         Type of the static member.
+    /// @param Flags      Flags to encode member attribute, e.g. private.
+    /// @param Val        Const initializer of the member.
+    DIType createStaticMemberType(DIDescriptor Scope, StringRef Name,
+                                  DIFile File, unsigned LineNo, DIType Ty,
+                                  unsigned Flags, llvm::Value *Val);
+
     /// createObjCIVar - Create debugging information entry for Objective-C
     /// instance variable.
     /// @param Name         Member name.
@@ -402,10 +415,12 @@ namespace llvm {
     /// @param isLocalToUnit Boolean flag indicate whether this variable is
     ///                      externally visible or not.
     /// @param Val         llvm::Value of the variable.
+    /// @param Decl        Reference to the corresponding declaration.
     DIGlobalVariable
     createStaticVariable(DIDescriptor Context, StringRef Name, 
                          StringRef LinkageName, DIFile File, unsigned LineNo, 
-                         DIType Ty, bool isLocalToUnit, llvm::Value *Val);
+                         DIType Ty, bool isLocalToUnit, llvm::Value *Val,
+                         MDNode *Decl = NULL);
 
 
     /// createLocalVariable - Create a new descriptor for the specified 

include/llvm/DebugInfo.h

@@ -62,7 +62,8 @@ namespace llvm {
       FlagPrototyped         = 1 << 8,
       FlagObjcClassComplete  = 1 << 9,
       FlagObjectPointer      = 1 << 10,
-      FlagVector             = 1 << 11
+      FlagVector             = 1 << 11,
+      FlagStaticMember       = 1 << 12
     };
   protected:
     const MDNode *DbgNode;
@@ -300,6 +301,9 @@ namespace llvm {
     bool isVector() const {
       return (getFlags() & FlagVector) != 0;
     }
+    bool isStaticMember() const {
+      return (getFlags() & FlagStaticMember) != 0;
+    }
     bool isValid() const {
       return DbgNode && (isBasicType() || isDerivedType() || isCompositeType());
     }
@@ -337,7 +341,8 @@ namespace llvm {
   };
 
   /// DIDerivedType - A simple derived type, like a const qualified type,
-  /// a typedef, a pointer or reference, etc.
+  /// a typedef, a pointer or reference, et cetera.  Or, a data member of
+  /// a class/struct/union.
   class DIDerivedType : public DIType {
     friend class DIDescriptor;
     void printInternal(raw_ostream &OS) const;
@@ -363,6 +368,11 @@ namespace llvm {
       return getFieldAs<DIType>(10);
     }
 
+    Constant *getConstant() const {
+      assert((getTag() == dwarf::DW_TAG_member) && isStaticMember());
+      return getConstantField(10);
+    }
+
     StringRef getObjCPropertyName() const {
       if (getVersion() > LLVMDebugVersion11)
         return StringRef();
@@ -620,6 +630,9 @@ namespace llvm {
 
     GlobalVariable *getGlobal() const { return getGlobalVariableField(11); }
     Constant *getConstant() const   { return getConstantField(11); }
+    DIDerivedType getStaticDataMemberDeclaration() const {
+      return getFieldAs<DIDerivedType>(12);
+    }
 
     /// Verify - Verify that a global variable descriptor is well formed.
     bool Verify() const;

lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

@@ -670,18 +670,21 @@ void CompileUnit::addTemplateParams(DIE &Buffer, DIArray TParams) {
   }
 }
 
+/// getOrCreateContextDIE - Get context owner's DIE.
+DIE *CompileUnit::getOrCreateContextDIE(DIDescriptor Context) {
+  if (Context.isType())
+    return getOrCreateTypeDIE(DIType(Context));
+  else if (Context.isNameSpace())
+    return getOrCreateNameSpace(DINameSpace(Context));
+  else if (Context.isSubprogram())
+    return getOrCreateSubprogramDIE(DISubprogram(Context));
+  else 
+    return getDIE(Context);
+}
+
 /// addToContextOwner - Add Die into the list of its context owner's children.
 void CompileUnit::addToContextOwner(DIE *Die, DIDescriptor Context) {
-  if (Context.isType()) {
+  if (DIE *ContextDIE = getOrCreateContextDIE(Context))
-    DIE *ContextDIE = getOrCreateTypeDIE(DIType(Context));
-    ContextDIE->addChild(Die);
-  } else if (Context.isNameSpace()) {
-    DIE *ContextDIE = getOrCreateNameSpace(DINameSpace(Context));
-    ContextDIE->addChild(Die);
-  } else if (Context.isSubprogram()) {
-    DIE *ContextDIE = getOrCreateSubprogramDIE(DISubprogram(Context));
-    ContextDIE->addChild(Die);
-  } else if (DIE *ContextDIE = getDIE(Context))
     ContextDIE->addChild(Die);
   else
     addDie(Die);
@@ -925,22 +928,15 @@ void CompileUnit::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
             dwarf::DW_ACCESS_public);
         if (SP.isExplicit())
           addFlag(ElemDie, dwarf::DW_AT_explicit);
-      }
-      else if (Element.isVariable()) {
-        DIVariable DV(Element);
-        ElemDie = new DIE(dwarf::DW_TAG_variable);
-        addString(ElemDie, dwarf::DW_AT_name, DV.getName());
-        addType(ElemDie, DV.getType());
-        addFlag(ElemDie, dwarf::DW_AT_declaration);
-        addFlag(ElemDie, dwarf::DW_AT_external);
-        addSourceLine(ElemDie, DV);
       } else if (Element.isDerivedType()) {
         DIDerivedType DDTy(Element);
         if (DDTy.getTag() == dwarf::DW_TAG_friend) {
           ElemDie = new DIE(dwarf::DW_TAG_friend);
           addType(ElemDie, DDTy.getTypeDerivedFrom(), dwarf::DW_AT_friend);
-        } else
+        } else if (DDTy.isStaticMember())
-          ElemDie = createMemberDIE(DIDerivedType(Element));
+          ElemDie = createStaticMemberDIE(DDTy);
+        else
+          ElemDie = createMemberDIE(DDTy);
       } else if (Element.isObjCProperty()) {
         DIObjCProperty Property(Element);
         ElemDie = new DIE(Property.getTag());
@@ -1256,33 +1252,48 @@ void CompileUnit::createGlobalVariableDIE(const MDNode *N) {
   if (!GV.Verify())
     return;
 
-  DIE *VariableDIE = new DIE(GV.getTag());
-  // Add to map.
-  insertDIE(N, VariableDIE);
-
-  // Add name.
-  addString(VariableDIE, dwarf::DW_AT_name, GV.getDisplayName());
-  StringRef LinkageName = GV.getLinkageName();
-  bool isGlobalVariable = GV.getGlobal() != NULL;
-  if (!LinkageName.empty() && isGlobalVariable)
-    addString(VariableDIE, dwarf::DW_AT_MIPS_linkage_name,
-              getRealLinkageName(LinkageName));
-  // Add type.
-  DIType GTy = GV.getType();
-  addType(VariableDIE, GTy);
-
-  // Add scoping info.
-  if (!GV.isLocalToUnit())
-    addFlag(VariableDIE, dwarf::DW_AT_external);
-
-  // Add line number info.
-  addSourceLine(VariableDIE, GV);
-  // Add to context owner.
   DIDescriptor GVContext = GV.getContext();
-  addToContextOwner(VariableDIE, GVContext);
+  DIType GTy = GV.getType();
+
+  // If this is a static data member definition, some attributes belong
+  // to the declaration DIE.
+  DIE *VariableDIE = NULL;
+  DIDerivedType SDMDecl = GV.getStaticDataMemberDeclaration();
+  if (SDMDecl.Verify()) {
+    assert(SDMDecl.isStaticMember() && "Expected static member decl");
+    // We need the declaration DIE that is in the static member's class.
+    // But that class might not exist in the DWARF yet.
+    // Creating the class will create the static member decl DIE.
+    getOrCreateContextDIE(SDMDecl.getContext());
+    VariableDIE = getDIE(SDMDecl);
+    assert(VariableDIE && "Static member decl has no context?");
+  }
+
+  // If this is not a static data member definition, create the variable
+  // DIE and add the initial set of attributes to it.
+  if (!VariableDIE) {
+    VariableDIE = new DIE(GV.getTag());
+    // Add to map.
+    insertDIE(N, VariableDIE);
+
+    // Add name and type.
+    addString(VariableDIE, dwarf::DW_AT_name, GV.getDisplayName());
+    addType(VariableDIE, GTy);
+
+    // Add scoping info.
+    if (!GV.isLocalToUnit())
+      addFlag(VariableDIE, dwarf::DW_AT_external);
+
+    // Add line number info.
+    addSourceLine(VariableDIE, GV);
+    // Add to context owner.
+    addToContextOwner(VariableDIE, GVContext);
+  }
+
   // Add location.
   bool addToAccelTable = false;
   DIE *VariableSpecDIE = NULL;
+  bool isGlobalVariable = GV.getGlobal() != NULL;
   if (isGlobalVariable) {
     addToAccelTable = true;
     DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
@@ -1298,11 +1309,18 @@ void CompileUnit::createGlobalVariableDIE(const MDNode *N) {
       addDIEEntry(VariableSpecDIE, dwarf::DW_AT_specification,
                   dwarf::DW_FORM_ref4, VariableDIE);
       addBlock(VariableSpecDIE, dwarf::DW_AT_location, 0, Block);
-      addFlag(VariableDIE, dwarf::DW_AT_declaration);
+      // A static member's declaration is already flagged as such.
+      if (!SDMDecl.Verify())
+        addFlag(VariableDIE, dwarf::DW_AT_declaration);
       addDie(VariableSpecDIE);
     } else {
       addBlock(VariableDIE, dwarf::DW_AT_location, 0, Block);
     }
+    // Add linkage name.
+    StringRef LinkageName = GV.getLinkageName();
+    if (!LinkageName.empty() && isGlobalVariable)
+      addString(VariableDIE, dwarf::DW_AT_MIPS_linkage_name,
+                getRealLinkageName(LinkageName));
   } else if (const ConstantInt *CI =
              dyn_cast_or_null<ConstantInt>(GV.getConstant()))
     addConstantValue(VariableDIE, CI, GTy.isUnsignedDIType());
@@ -1638,3 +1656,36 @@ DIE *CompileUnit::createMemberDIE(DIDerivedType DT) {
   }
   return MemberDie;
 }
+
+/// createStaticMemberDIE - Create new DIE for C++ static member.
+DIE *CompileUnit::createStaticMemberDIE(const DIDerivedType DT) {
+  if (!DT.Verify())
+    return NULL;
+
+  DIE *StaticMemberDIE = new DIE(DT.getTag());
+  DIType Ty = DT.getTypeDerivedFrom();
+
+  addString(StaticMemberDIE, dwarf::DW_AT_name, DT.getName());
+  addType(StaticMemberDIE, Ty);
+  addSourceLine(StaticMemberDIE, DT);
+  addFlag(StaticMemberDIE, dwarf::DW_AT_external);
+  addFlag(StaticMemberDIE, dwarf::DW_AT_declaration);
+
+  // FIXME: We could omit private if the parent is a class_type, and
+  // public if the parent is something else.
+  if (DT.isProtected())
+    addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
+            dwarf::DW_ACCESS_protected);
+  else if (DT.isPrivate())
+    addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
+            dwarf::DW_ACCESS_private);
+  else
+    addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
+            dwarf::DW_ACCESS_public);
+
+  if (const ConstantInt *CI = dyn_cast_or_null<ConstantInt>(DT.getConstant()))
+    addConstantValue(StaticMemberDIE, CI, Ty.isUnsignedDIType());
+
+  insertDIE(DT, StaticMemberDIE);
+  return StaticMemberDIE;
+}

lib/CodeGen/AsmPrinter/DwarfCompileUnit.h

@@ -86,6 +86,9 @@ class CompileUnit {
   /// DWARF version doesn't handle the language, return -1.
   int64_t getDefaultLowerBound() const;
 
+  /// getOrCreateContextDIE - Get context owner's DIE.
+  DIE *getOrCreateContextDIE(DIDescriptor Context);
+
 public:
   CompileUnit(unsigned UID, unsigned L, DIE *D, AsmPrinter *A, DwarfDebug *DW,
               DwarfUnits *);
@@ -344,6 +347,9 @@ public:
   /// createMemberDIE - Create new member DIE.
   DIE *createMemberDIE(DIDerivedType DT);
 
+  /// createStaticMemberDIE - Create new static data member DIE.
+  DIE *createStaticMemberDIE(DIDerivedType DT);
+
 private:
 
   // DIEValueAllocator - All DIEValues are allocated through this allocator.

lib/IR/DIBuilder.cpp

@@ -350,6 +350,30 @@ DIType DIBuilder::createMemberType(DIDescriptor Scope, StringRef Name,
   return DIType(MDNode::get(VMContext, Elts));
 }
 
+/// createStaticMemberType - Create debugging information entry for a
+/// C++ static data member.
+DIType DIBuilder::createStaticMemberType(DIDescriptor Scope, StringRef Name,
+                                         DIFile File, unsigned LineNumber,
+                                         DIType Ty, unsigned Flags,
+                                         llvm::Value *Val) {
+  // TAG_member is encoded in DIDerivedType format.
+  Flags |= DIDescriptor::FlagStaticMember;
+  Value *Elts[] = {
+    GetTagConstant(VMContext, dwarf::DW_TAG_member),
+    getNonCompileUnitScope(Scope),
+    MDString::get(VMContext, Name),
+    File,
+    ConstantInt::get(Type::getInt32Ty(VMContext), LineNumber),
+    ConstantInt::get(Type::getInt64Ty(VMContext), 0/*SizeInBits*/),
+    ConstantInt::get(Type::getInt64Ty(VMContext), 0/*AlignInBits*/),
+    ConstantInt::get(Type::getInt64Ty(VMContext), 0/*OffsetInBits*/),
+    ConstantInt::get(Type::getInt32Ty(VMContext), Flags),
+    Ty,
+    Val
+  };
+  return DIType(MDNode::get(VMContext, Elts));
+}
+
 /// createObjCIVar - Create debugging information entry for Objective-C
 /// instance variable.
 DIType DIBuilder::createObjCIVar(StringRef Name,
@@ -787,7 +811,8 @@ createGlobalVariable(StringRef Name, DIFile F, unsigned LineNumber,
     Ty,
     ConstantInt::get(Type::getInt32Ty(VMContext), isLocalToUnit),
     ConstantInt::get(Type::getInt32Ty(VMContext), 1), /* isDefinition*/
-    Val
+    Val,
+    DIDescriptor()
   };
   MDNode *Node = MDNode::get(VMContext, Elts);
   AllGVs.push_back(Node);
@@ -799,7 +824,7 @@ createGlobalVariable(StringRef Name, DIFile F, unsigned LineNumber,
 DIGlobalVariable DIBuilder::
 createStaticVariable(DIDescriptor Context, StringRef Name,
                      StringRef LinkageName, DIFile F, unsigned LineNumber,
-                     DIType Ty, bool isLocalToUnit, Value *Val) {
+                     DIType Ty, bool isLocalToUnit, Value *Val, MDNode *Decl) {
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_variable),
     Constant::getNullValue(Type::getInt32Ty(VMContext)),
@@ -812,7 +837,8 @@ createStaticVariable(DIDescriptor Context, StringRef Name,
     Ty,
     ConstantInt::get(Type::getInt32Ty(VMContext), isLocalToUnit),
     ConstantInt::get(Type::getInt32Ty(VMContext), 1), /* isDefinition*/
-    Val
+    Val,
+    DIDescriptor(Decl)
   };
   MDNode *Node = MDNode::get(VMContext, Elts);
   AllGVs.push_back(Node);

lib/IR/DebugInfo.cpp

@@ -1101,6 +1101,8 @@ void DIType::printInternal(raw_ostream &OS) const {
     OS << " [fwd]";
   if (isVector())
     OS << " [vector]";
+  if (isStaticMember())
+    OS << " [static]";
 }
 
 void DIDerivedType::printInternal(raw_ostream &OS) const {