DebugInfo: Omit debug info for dynamic classes in TUs that do not have the vtable...

This reduces Clang's .dwo (fission debug info) size by 23% over
Clang+LLVM.

llvm-svn: 188576

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index d1ee2f60c8e5bae60e7ef442e9579dd0900476fe..f7ea474daa68e04f28c975bc0be8d877fc6b56bd 100644 (file)
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -865,7 +865,7 @@ CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
   }
 }
 
-/// CollectRecordStaticField - Helper for CollectRecordFields.
+/// Helper for CollectRecordFields.
 llvm::DIDerivedType
 CGDebugInfo::CreateRecordStaticField(const VarDecl *Var,
                                      llvm::DIType RecordTy) {
@@ -951,7 +951,7 @@ void CGDebugInfo::CollectRecordFields(const RecordDecl *record,
     for (RecordDecl::decl_iterator I = record->decls_begin(),
            E = record->decls_end(); I != E; ++I)
       if (const VarDecl *V = dyn_cast<VarDecl>(*I))
-        elements.push_back(CreateRecordStaticField(V, RecordTy));
+        elements.push_back(getOrCreateStaticDataMemberDeclaration(V, RecordTy));
       else if (FieldDecl *field = dyn_cast<FieldDecl>(*I)) {
         CollectRecordNormalField(field, layout.getFieldOffset(fieldNo),
                                  tunit, elements, RecordTy);
@@ -1122,8 +1122,14 @@ CollectCXXMemberFunctions(const CXXRecordDecl *RD, llvm::DIFile Unit,
     if (D->isImplicit())
       continue;
 
-    if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
-      EltTys.push_back(CreateCXXMemberFunction(Method, Unit, RecordTy));
+    if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
+      llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator MI =
+          SPCache.find(Method->getCanonicalDecl());
+      if (MI == SPCache.end())
+        EltTys.push_back(CreateCXXMemberFunction(Method, Unit, RecordTy));
+      else
+        EltTys.push_back(MI->second);
+    }
   }
 }
 
@@ -1408,10 +1414,18 @@ void CGDebugInfo::completeType(const RecordDecl *RD) {
 }
 
 void CGDebugInfo::completeRequiredType(const RecordDecl *RD) {
+  if (const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD))
+    if (CXXDecl->isDynamicClass())
+      return;
+
   QualType Ty = CGM.getContext().getRecordType(RD);
   llvm::DIType T = getTypeOrNull(Ty);
-  if (!T || !T.isForwardDecl())
-    return;
+  if (T && T.isForwardDecl())
+    completeClassData(RD);
+}
+
+void CGDebugInfo::completeClassData(const RecordDecl *RD) {
+  QualType Ty = CGM.getContext().getRecordType(RD);
   void* TyPtr = Ty.getAsOpaquePtr();
   if (CompletedTypeCache.count(TyPtr))
     return;
@@ -1424,14 +1438,23 @@ void CGDebugInfo::completeRequiredType(const RecordDecl *RD) {
 /// CreateType - get structure or union type.
 llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty, bool Declaration) {
   RecordDecl *RD = Ty->getDecl();
+  const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD);
   // Limited debug info should only remove struct definitions that can
   // safely be replaced by a forward declaration in the source code.
-  if (DebugKind <= CodeGenOptions::LimitedDebugInfo && Declaration &&
-      !RD->isCompleteDefinitionRequired() && CGM.getLangOpts().CPlusPlus) {
+  if ((DebugKind <= CodeGenOptions::LimitedDebugInfo && Declaration &&
+       !RD->isCompleteDefinitionRequired() && CGM.getLangOpts().CPlusPlus) ||
+      (CXXDecl && CXXDecl->hasDefinition() && CXXDecl->isDynamicClass())) {
     llvm::DIDescriptor FDContext =
       getContextDescriptor(cast<Decl>(RD->getDeclContext()));
     llvm::DIType RetTy = getOrCreateRecordFwdDecl(RD, FDContext);
-    return RetTy;
+    // FIXME: This is conservatively correct. If we return a non-forward decl
+    // that's not a full definition (such as those created by
+    // createContextChain) then getOrCreateType will record is as a complete
+    // type and we'll never record all its members. But this means we're
+    // emitting full debug info in TUs where GCC successfully emits a partial
+    // definition of the type.
+    if (RetTy.isForwardDecl())
+      return RetTy;
   }
 
   return CreateTypeDefinition(Ty);
@@ -1466,6 +1489,13 @@ llvm::DIType CGDebugInfo::CreateTypeDefinition(const RecordType *Ty) {
 
   // Convert all the elements.
   SmallVector<llvm::Value *, 16> EltTys;
+  llvm::DIArray PrevMem = FwdDecl.getTypeArray();
+  unsigned NumElements = PrevMem.getNumElements();
+  if (NumElements == 1 && !PrevMem.getElement(0))
+    NumElements = 0;
+  EltTys.reserve(NumElements);
+  for (unsigned i = 0; i != NumElements; ++i)
+    EltTys.push_back(PrevMem.getElement(i));
 
   // Note: The split of CXXDecl information here is intentional, the
   // gdb tests will depend on a certain ordering at printout. The debug
@@ -2291,7 +2321,7 @@ llvm::DISubprogram CGDebugInfo::getFunctionDeclaration(const Decl *D) {
   llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator
     MI = SPCache.find(FD->getCanonicalDecl());
   if (MI == SPCache.end()) {
-    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
+    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD->getCanonicalDecl())) {
       llvm::DICompositeType T(S);
       llvm::DISubprogram SP = CreateCXXMemberFunction(MD, getOrCreateFile(MD->getLocation()), T);
       T.addMember(SP);
@@ -2997,19 +3027,35 @@ void CGDebugInfo::EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
   DbgDecl->setDebugLoc(llvm::DebugLoc::get(line, column, scope));
 }
 
-/// getStaticDataMemberDeclaration - If D is an out-of-class definition of
-/// a static data member of a class, find its corresponding in-class
-/// declaration.
-llvm::DIDerivedType CGDebugInfo::getStaticDataMemberDeclaration(const VarDecl *D) {
-  if (D->isStaticDataMember()) {
-    llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator
-      MI = StaticDataMemberCache.find(D->getCanonicalDecl());
-    if (MI != StaticDataMemberCache.end())
-      // Verify the info still exists.
-      if (llvm::Value *V = MI->second)
-        return llvm::DIDerivedType(cast<llvm::MDNode>(V));
+/// If D is an out-of-class definition of a static data member of a class, find
+/// its corresponding in-class declaration.
+llvm::DIDerivedType
+CGDebugInfo::getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D) {
+  if (!D->isStaticDataMember())
+    return llvm::DIDerivedType();
+  llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator MI =
+      StaticDataMemberCache.find(D->getCanonicalDecl());
+  if (MI != StaticDataMemberCache.end()) {
+    assert(MI->second && "Static data member declaration should still exist");
+    return llvm::DIDerivedType(cast<llvm::MDNode>(MI->second));
+  }
+  llvm::DICompositeType Ctxt(
+      getContextDescriptor(cast<Decl>(D->getDeclContext())));
+  llvm::DIDerivedType T = CreateRecordStaticField(D, Ctxt);
+  Ctxt.addMember(T);
+  return T;
+}
+
+llvm::DIDerivedType
+CGDebugInfo::getOrCreateStaticDataMemberDeclaration(const VarDecl *D,
+                                            llvm::DICompositeType Ctxt) {
+  llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator MI =
+      StaticDataMemberCache.find(D->getCanonicalDecl());
+  if (MI != StaticDataMemberCache.end()) {
+    assert(MI->second && "Static data member declaration should still exist");
+    return llvm::DIDerivedType(cast<llvm::MDNode>(MI->second));
   }
-  return llvm::DIDerivedType();
+  return CreateRecordStaticField(D, Ctxt);
 }
 
 /// EmitGlobalVariable - Emit information about a global variable.
@@ -3041,11 +3087,10 @@ void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
     LinkageName = StringRef();
   llvm::DIDescriptor DContext =
     getContextDescriptor(dyn_cast<Decl>(D->getDeclContext()));
-  llvm::DIGlobalVariable GV =
-      DBuilder.createStaticVariable(DContext, DeclName, LinkageName, Unit,
-                                    LineNo, getOrCreateType(T, Unit),
-                                    Var->hasInternalLinkage(), Var,
-                                    getStaticDataMemberDeclaration(D));
+  llvm::DIGlobalVariable GV = DBuilder.createStaticVariable(
+      DContext, DeclName, LinkageName, Unit, LineNo, getOrCreateType(T, Unit),
+      Var->hasInternalLinkage(), Var,
+      getOrCreateStaticDataMemberDeclarationOrNull(D));
   DeclCache.insert(std::make_pair(D->getCanonicalDecl(), llvm::WeakVH(GV)));
 }
 
@@ -3093,7 +3138,7 @@ void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD,
     return;
   llvm::DIGlobalVariable GV = DBuilder.createStaticVariable(
       Unit, Name, Name, Unit, getLineNumber(VD->getLocation()), Ty, true, Init,
-      getStaticDataMemberDeclaration(cast<VarDecl>(VD)));
+      getOrCreateStaticDataMemberDeclarationOrNull(cast<VarDecl>(VD)));
   DeclCache.insert(std::make_pair(VD->getCanonicalDecl(), llvm::WeakVH(GV)));
 }
 

diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index 39436e18a72d6781271bc1a9646a9a6d880f0fa3..51a937bfced478d2276973ca8cbfe60833fcda67 100644 (file)
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -290,7 +290,7 @@ public:
 
   void completeType(const RecordDecl *RD);
   void completeRequiredType(const RecordDecl *RD);
-
+  void completeClassData(const RecordDecl *RD);
 
 private:
   /// EmitDeclare - Emit call to llvm.dbg.declare for a variable declaration.
@@ -353,10 +353,13 @@ private:
   /// declaration for the given method definition.
   llvm::DISubprogram getFunctionDeclaration(const Decl *D);
 
-  /// getStaticDataMemberDeclaration - Return debug info descriptor to
-  /// describe in-class static data member declaration for the given
-  /// out-of-class definition.
-  llvm::DIDerivedType getStaticDataMemberDeclaration(const VarDecl *D);
+  /// Return debug info descriptor to describe in-class static data member
+  /// declaration for the given out-of-class definition.
+  llvm::DIDerivedType
+  getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D);
+  llvm::DIDerivedType
+  getOrCreateStaticDataMemberDeclaration(const VarDecl *D,
+                                         llvm::DICompositeType Ctxt);
 
   /// getFunctionName - Get function name for the given FunctionDecl. If the
   /// name is constructred on demand (e.g. C++ destructor) then the name

diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index c7bb54e0699659cc5591730a5e5644e051ea9a04..6649578fc09c0100e04442eb7701efe770cf9491 100644 (file)
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -828,6 +828,9 @@ CodeGenVTables::GenerateClassData(const CXXRecordDecl *RD) {
     VFTContext->getVFPtrOffsets(RD);
   }
 
+  if (CGDebugInfo *DI = CGM.getModuleDebugInfo())
+    DI->completeClassData(RD);
+
   // First off, check whether we've already emitted the v-table and
   // associated stuff.
   llvm::GlobalVariable *VTable = GetAddrOfVTable(RD);

diff --git a/clang/test/CodeGenCXX/debug-info-class.cpp b/clang/test/CodeGenCXX/debug-info-class.cpp
index df2492603e360bc182a54ce00a0ed0a7fe263d7e..76cc1e3e27c2148d351d9af9b9f06d03f6b9734d 100644 (file)
--- a/clang/test/CodeGenCXX/debug-info-class.cpp
+++ b/clang/test/CodeGenCXX/debug-info-class.cpp
@@ -12,6 +12,32 @@ class B {
 public:
   virtual ~B();
 };
+
+B::~B() {
+}
+
+struct C {
+  static int s;
+  virtual ~C();
+};
+
+C::~C() {
+}
+
+struct D {
+  D();
+  virtual ~D();
+  void func() {
+  }
+};
+
+struct E {
+  E();
+  virtual ~E();
+  virtual void func() {
+  }
+};
+
 struct A {
   int one;
   static const int HdrSize = 52;
@@ -21,6 +47,11 @@ struct A {
   }
 };
 
+void f1() {
+  D x;
+  x.func();
+  E y;
+}
 
 int main(int argc, char **argv) {
   B b;
@@ -40,9 +71,20 @@ int main(int argc, char **argv) {
 // CHECK: DW_TAG_structure_type ] [foo]
 // CHECK: DW_TAG_class_type ] [bar]
 // CHECK: DW_TAG_union_type ] [baz]
-// CHECK: DW_TAG_structure_type ] [A]
-// CHECK: HdrSize
 // CHECK: DW_TAG_class_type ] [B]
 // CHECK: metadata !"_vptr$B", {{.*}}, i32 64, metadata !{{.*}}} ; [ DW_TAG_member ]
-// CHECK: ![[EXCEPTLOC]] = metadata !{i32 31,
-// CHECK: ![[RETLOC]] = metadata !{i32 30,
+
+// CHECK: [[C:![0-9]*]] = {{.*}} metadata [[C_MEM:![0-9]*]], i32 0, metadata [[C]], null} ; [ DW_TAG_structure_type ] [C] {{.*}} [def]
+// CHECK: [[C_MEM]] = metadata !{metadata [[C_VPTR:![0-9]*]], metadata [[C_S:![0-9]*]], metadata [[C_DTOR:![0-9]*]]}
+// CHECK: [[C_VPTR]] = {{.*}} ; [ DW_TAG_member ] [_vptr$C] {{.*}} [artificial]
+// CHECK: [[C_S]] = {{.*}} ; [ DW_TAG_member ] [s] {{.*}} [static] [from int]
+// CHECK: [[C_DTOR]] = {{.*}} ; [ DW_TAG_subprogram ] {{.*}} [~C]
+
+// CHECK: ; [ DW_TAG_structure_type ] [A]
+// CHECK: HdrSize
+// CHECK: metadata [[D_MEM:![0-9]*]], i32 0, null} ; [ DW_TAG_structure_type ] [D] {{.*}} [decl]
+// CHECK: [[D_MEM]] = metadata !{metadata [[D_FUNC:![0-9]*]]}
+// CHECK: [[D_FUNC]] = {{.*}} ; [ DW_TAG_subprogram ] {{.*}} [func]
+// CHECK: null, i32 0, null} ; [ DW_TAG_structure_type ] [E] {{.*}} [decl]
+// CHECK: ![[EXCEPTLOC]] = metadata !{i32 62,
+// CHECK: ![[RETLOC]] = metadata !{i32 61,