PR16214: Debug Info: -flimit-debug-info doesn't omit definitions for types used via...

In an effort to make -flimit-debug-info more consistent I over-shot the
mark & made types used via typedefs never produce definitions in the
debug info (even if the type was used in a way that would require a
definition).

The fix for this is to do exactly what I was hoping to do at some point
- plumb the declaration/definition choice through the various layers of
"CreateType" in CGDebugInfo. In this way we can produce declarations
whenever they are sufficient & definitions otherwise - including when
qualifiers are used, for example (discovered in PR14467). This may not
be complete (there may be other types/situations where we need to
propagate the "declaration/definition" choice) but it lays the basic
foundation which we can enhance in future iterations.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183296 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index c1d095ddd6c62fc5a0cbeecd511b688b92671317..80d5f101ee98df7bb468fbf0c5d2a39074841362 100644 (file)
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -501,7 +501,7 @@ llvm::DIType CGDebugInfo::CreateType(const ComplexType *Ty) {
 
 /// CreateCVRType - Get the qualified type from the cache or create
 /// a new one if necessary.
-llvm::DIType CGDebugInfo::CreateQualifiedType(QualType Ty, llvm::DIFile Unit) {
+llvm::DIType CGDebugInfo::CreateQualifiedType(QualType Ty, llvm::DIFile Unit, bool Declaration) {
   QualifierCollector Qc;
   const Type *T = Qc.strip(Ty);
 
@@ -527,7 +527,7 @@ llvm::DIType CGDebugInfo::CreateQualifiedType(QualType Ty, llvm::DIFile Unit) {
     return getOrCreateType(QualType(T, 0), Unit);
   }
 
-  llvm::DIType FromTy = getOrCreateType(Qc.apply(CGM.getContext(), T), Unit);
+  llvm::DIType FromTy = getOrCreateType(Qc.apply(CGM.getContext(), T), Unit, Declaration);
 
   // No need to fill in the Name, Line, Size, Alignment, Offset in case of
   // CVR derived types.
@@ -613,27 +613,7 @@ llvm::DIType CGDebugInfo::getOrCreateTypeDeclaration(QualType PointeeTy,
                                                      llvm::DIFile Unit) {
   if (DebugKind > CodeGenOptions::LimitedDebugInfo)
     return getOrCreateType(PointeeTy, Unit);
-
-  // Limit debug info for the pointee type.
-
-  // If we have an existing type, use that, it's still smaller than creating
-  // a new type.
-  llvm::DIType Ty = getTypeOrNull(PointeeTy);
-  if (Ty.Verify()) return Ty;
-
-  // Handle qualifiers.
-  if (PointeeTy.hasLocalQualifiers())
-    return CreateQualifiedType(PointeeTy, Unit);
-
-  if (const RecordType *RTy = dyn_cast<RecordType>(PointeeTy)) {
-    RecordDecl *RD = RTy->getDecl();
-    llvm::DIDescriptor FDContext =
-      getContextDescriptor(cast<Decl>(RD->getDeclContext()));
-    llvm::DIType RetTy = createRecordFwdDecl(RD, FDContext);
-    TypeCache[QualType(RTy, 0).getAsOpaquePtr()] = RetTy;
-    return RetTy;
-  }
-  return getOrCreateType(PointeeTy, Unit);
+  return getOrCreateType(PointeeTy, Unit, true);
 }
 
 llvm::DIType CGDebugInfo::CreatePointerLikeType(unsigned Tag,
@@ -730,11 +710,12 @@ llvm::DIType CGDebugInfo::CreateType(const BlockPointerType *Ty,
   return BlockLiteralGeneric;
 }
 
-llvm::DIType CGDebugInfo::CreateType(const TypedefType *Ty, llvm::DIFile Unit) {
+llvm::DIType CGDebugInfo::CreateType(const TypedefType *Ty, llvm::DIFile Unit,
+                                     bool Declaration) {
   // Typedefs are derived from some other type.  If we have a typedef of a
   // typedef, make sure to emit the whole chain.
   llvm::DIType Src =
-      getOrCreateTypeDeclaration(Ty->getDecl()->getUnderlyingType(), Unit);
+      getOrCreateType(Ty->getDecl()->getUnderlyingType(), Unit, Declaration);
   if (!Src.Verify())
     return llvm::DIType();
   // We don't set size information, but do specify where the typedef was
@@ -1394,8 +1375,15 @@ llvm::DIType CGDebugInfo::getOrCreateInterfaceType(QualType D,
 }
 
 /// CreateType - get structure or union type.
-llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty) {
+llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty, bool Declaration) {
   RecordDecl *RD = Ty->getDecl();
+  if (Declaration) {
+    llvm::DIDescriptor FDContext =
+      getContextDescriptor(cast<Decl>(RD->getDeclContext()));
+    llvm::DIType RetTy = createRecordFwdDecl(RD, FDContext);
+    TypeCache[QualType(Ty, 0).getAsOpaquePtr()] = RetTy;
+    return RetTy;
+  }
 
   // Get overall information about the record type for the debug info.
   llvm::DIFile DefUnit = getOrCreateFile(RD->getLocation());
@@ -1908,7 +1896,7 @@ llvm::Value *CGDebugInfo::getCachedInterfaceTypeOrNull(QualType Ty) {
 
 /// getOrCreateType - Get the type from the cache or create a new
 /// one if necessary.
-llvm::DIType CGDebugInfo::getOrCreateType(QualType Ty, llvm::DIFile Unit) {
+llvm::DIType CGDebugInfo::getOrCreateType(QualType Ty, llvm::DIFile Unit, bool Declaration) {
   if (Ty.isNull())
     return llvm::DIType();
 
@@ -1921,7 +1909,7 @@ llvm::DIType CGDebugInfo::getOrCreateType(QualType Ty, llvm::DIFile Unit) {
     return T;
 
   // Otherwise create the type.
-  llvm::DIType Res = CreateTypeNode(Ty, Unit);
+  llvm::DIType Res = CreateTypeNode(Ty, Unit, Declaration);
   void* TyPtr = Ty.getAsOpaquePtr();
 
   // And update the type cache.
@@ -1981,10 +1969,10 @@ ObjCInterfaceDecl *CGDebugInfo::getObjCInterfaceDecl(QualType Ty) {
 }
 
 /// CreateTypeNode - Create a new debug type node.
-llvm::DIType CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile Unit) {
+llvm::DIType CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile Unit, bool Declaration) {
   // Handle qualifiers, which recursively handles what they refer to.
   if (Ty.hasLocalQualifiers())
-    return CreateQualifiedType(Ty, Unit);
+    return CreateQualifiedType(Ty, Unit, Declaration);
 
   const char *Diag = 0;
 
@@ -2015,9 +2003,9 @@ llvm::DIType CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile Unit) {
   case Type::BlockPointer:
     return CreateType(cast<BlockPointerType>(Ty), Unit);
   case Type::Typedef:
-    return CreateType(cast<TypedefType>(Ty), Unit);
+    return CreateType(cast<TypedefType>(Ty), Unit, Declaration);
   case Type::Record:
-    return CreateType(cast<RecordType>(Ty));
+    return CreateType(cast<RecordType>(Ty), Declaration);
   case Type::Enum:
     return CreateEnumType(cast<EnumType>(Ty)->getDecl());
   case Type::FunctionProto:
@@ -2174,7 +2162,7 @@ llvm::DIType CGDebugInfo::CreateLimitedTypeNode(QualType Ty,llvm::DIFile Unit) {
   case Type::Record:
     return CreateLimitedType(cast<RecordType>(Ty));
   default:
-    return CreateTypeNode(Ty, Unit);
+    return CreateTypeNode(Ty, Unit, false);
   }
 }
 

diff --git a/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index cee96f6d9df25744cc77ca09ab5053f71e45aa65..fc62600c32525705ad5db2d2b4af7b27058a26fe 100644 (file)
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@@ -108,14 +108,14 @@ class CGDebugInfo {
   unsigned Checksum(const ObjCInterfaceDecl *InterfaceDecl);
   llvm::DIType CreateType(const BuiltinType *Ty);
   llvm::DIType CreateType(const ComplexType *Ty);
-  llvm::DIType CreateQualifiedType(QualType Ty, llvm::DIFile F);
-  llvm::DIType CreateType(const TypedefType *Ty, llvm::DIFile F);
+  llvm::DIType CreateQualifiedType(QualType Ty, llvm::DIFile F, bool Declaration);
+  llvm::DIType CreateType(const TypedefType *Ty, llvm::DIFile F, bool Declaration);
   llvm::DIType CreateType(const ObjCObjectPointerType *Ty,
                           llvm::DIFile F);
   llvm::DIType CreateType(const PointerType *Ty, llvm::DIFile F);
   llvm::DIType CreateType(const BlockPointerType *Ty, llvm::DIFile F);
   llvm::DIType CreateType(const FunctionType *Ty, llvm::DIFile F);
-  llvm::DIType CreateType(const RecordType *Ty);
+  llvm::DIType CreateType(const RecordType *Ty, bool Declaration);
   llvm::DIType CreateLimitedType(const RecordType *Ty);
   llvm::DIType CreateType(const ObjCInterfaceType *Ty, llvm::DIFile F);
   llvm::DIType CreateType(const ObjCObjectType *Ty, llvm::DIFile F);
@@ -326,14 +326,14 @@ private:
 
   /// getOrCreateType - Get the type from the cache or create a new type if
   /// necessary.
-  llvm::DIType getOrCreateType(QualType Ty, llvm::DIFile F);
+  llvm::DIType getOrCreateType(QualType Ty, llvm::DIFile F, bool Declaration = false);
 
   /// getOrCreateLimitedType - Get the type from the cache or create a new
   /// partial type if necessary.
   llvm::DIType getOrCreateLimitedType(QualType Ty, llvm::DIFile F);
 
   /// CreateTypeNode - Create type metadata for a source language type.
-  llvm::DIType CreateTypeNode(QualType Ty, llvm::DIFile F);
+  llvm::DIType CreateTypeNode(QualType Ty, llvm::DIFile F, bool Declaration);
 
   /// getObjCInterfaceDecl - return the underlying ObjCInterfaceDecl
   /// if Ty is an ObjCInterface or a pointer to one.

diff --git a/test/CodeGenCXX/debug-info.cpp b/test/CodeGenCXX/debug-info.cpp
index b16c564e73842249710722fca2b82598fcf01d9e..4085b9ad3281467a8f85c5fefdd251408bfe9c9e 100644 (file)
--- a/test/CodeGenCXX/debug-info.cpp
+++ b/test/CodeGenCXX/debug-info.cpp
@@ -76,3 +76,27 @@ incomplete (*x)[3];
 // CHECK: [[INCARRAY]] = {{.*}}metadata [[INCTYPE:![0-9]*]], metadata {{![0-9]*}}, i32 0, i32 0} ; [ DW_TAG_array_type ] [line 0, size 0, align 0, offset 0] [from incomplete]
 // CHECK: [[INCTYPE]] = {{.*}} ; [ DW_TAG_structure_type ] [incomplete]{{.*}} [fwd]
 }
+
+namespace pr16214 {
+struct a {
+  int i;
+};
+
+typedef a at;
+
+struct b {
+};
+
+typedef b bt;
+
+void func() {
+  at a_inst;
+  bt *b_ptr_inst;
+  const bt *b_cnst_ptr_inst;
+}
+
+// CHECK: metadata [[A_MEM:![0-9]*]], i32 0, null, null} ; [ DW_TAG_structure_type ] [a]
+// CHECK: [[A_MEM]] = metadata !{metadata [[A_I:![0-9]*]], metadata !{{[0-9]*}}}
+// CHECK: [[A_I]] = {{.*}} ; [ DW_TAG_member ] [i] {{.*}} [from int]
+// CHECK: ; [ DW_TAG_structure_type ] [b] {{.*}}[fwd]
+}