Debug Info: Avoid completing class types when a definition is in a module.

This patch adds an early exit to CGDebugInfo::completeClassData() when
compiling with -gmodules and the to-be-completed type is available in
a clang module.

rdar://problem/23599990

llvm-svn: 308938

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index c9c450c..b78ba0d 100644 (file)
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -1766,6 +1766,29 @@ static bool isClassOrMethodDLLImport(const CXXRecordDecl *RD) {
   return false;
 }
 
+/// Does a type definition exist in an imported clang module?
+static bool isDefinedInClangModule(const RecordDecl *RD) {
+  // Only definitions that where imported from an AST file come from a module.
+  if (!RD || !RD->isFromASTFile())
+    return false;
+  // Anonymous entities cannot be addressed. Treat them as not from module.
+  if (!RD->isExternallyVisible() && RD->getName().empty())
+    return false;
+  if (auto *CXXDecl = dyn_cast<CXXRecordDecl>(RD)) {
+    if (!CXXDecl->isCompleteDefinition())
+      return false;
+    auto TemplateKind = CXXDecl->getTemplateSpecializationKind();
+    if (TemplateKind != TSK_Undeclared) {
+      // This is a template, check the origin of the first member.
+      if (CXXDecl->field_begin() == CXXDecl->field_end())
+        return TemplateKind == TSK_ExplicitInstantiationDeclaration;
+      if (!CXXDecl->field_begin()->isFromASTFile())
+        return false;
+    }
+  }
+  return true;
+}
+
 void CGDebugInfo::completeClassData(const RecordDecl *RD) {
   if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
     if (CXXRD->isDynamicClass() &&
@@ -1773,6 +1796,10 @@ void CGDebugInfo::completeClassData(const RecordDecl *RD) {
             llvm::GlobalValue::AvailableExternallyLinkage &&
         !isClassOrMethodDLLImport(CXXRD))
       return;
+
+  if (DebugTypeExtRefs && isDefinedInClangModule(RD->getDefinition()))
+    return;
+
   completeClass(RD);
 }
 
@@ -1799,29 +1826,6 @@ static bool hasExplicitMemberDefinition(CXXRecordDecl::method_iterator I,
   return false;
 }
 
-/// Does a type definition exist in an imported clang module?
-static bool isDefinedInClangModule(const RecordDecl *RD) {
-  // Only definitions that where imported from an AST file come from a module.
-  if (!RD || !RD->isFromASTFile())
-    return false;
-  // Anonymous entities cannot be addressed. Treat them as not from module.
-  if (!RD->isExternallyVisible() && RD->getName().empty())
-    return false;
-  if (auto *CXXDecl = dyn_cast<CXXRecordDecl>(RD)) {
-    if (!CXXDecl->isCompleteDefinition())
-      return false;
-    auto TemplateKind = CXXDecl->getTemplateSpecializationKind();
-    if (TemplateKind != TSK_Undeclared) {
-      // This is a template, check the origin of the first member.
-      if (CXXDecl->field_begin() == CXXDecl->field_end())
-        return TemplateKind == TSK_ExplicitInstantiationDeclaration;
-      if (!CXXDecl->field_begin()->isFromASTFile())
-        return false;
-    }
-  }
-  return true;
-}
-
 static bool shouldOmitDefinition(codegenoptions::DebugInfoKind DebugKind,
                                  bool DebugTypeExtRefs, const RecordDecl *RD,
                                  const LangOptions &LangOpts) {

diff --git a/clang/test/Modules/ExtDebugInfo.cpp b/clang/test/Modules/ExtDebugInfo.cpp
index ed9d1e8..97386bc 100644 (file)
--- a/clang/test/Modules/ExtDebugInfo.cpp
+++ b/clang/test/Modules/ExtDebugInfo.cpp
@@ -69,6 +69,8 @@ WithSpecializedBase<int> definedLocally4;
 
 void foo() {
   anon.i = GlobalStruct.i = GlobalUnion.i = GlobalEnum;
+  A a;
+  Virtual virt;
 }
 
 // CHECK: ![[CPP:.*]] = !DIFile(filename: {{.*}}ExtDebugInfo.cpp"
@@ -210,3 +212,10 @@ void foo() {
 // CHECK-SAME:           dwoId:
 // CHECK-PCH: !DICompileUnit({{.*}}splitDebugFilename:
 // CHECK-PCH:                dwoId: 18446744073709551614
+
+// CHECK: !DICompositeType(tag: DW_TAG_class_type, name: "A",
+// CHECK-SAME:             DIFlagFwdDecl, identifier: "_ZTS1A")
+
+// There is a full definition of the type available in the module.
+// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "Virtual",
+// CHECK-SAME:             DIFlagFwdDecl, identifier: "_ZTS7Virtual")

diff --git a/clang/test/Modules/Inputs/DebugCXX.h b/clang/test/Modules/Inputs/DebugCXX.h
index c9cd68f..1ccf8d3 100644 (file)
--- a/clang/test/Modules/Inputs/DebugCXX.h
+++ b/clang/test/Modules/Inputs/DebugCXX.h
@@ -54,9 +54,9 @@ namespace DebugCXX {
 }
 
 // Virtual class with a forward declaration.
-class FwdVirtual;
-class FwdVirtual {
-  virtual ~FwdVirtual() {}
+struct Virtual;
+struct Virtual {
+  virtual ~Virtual() {}
 };
 
 struct PureForwardDecl;

diff --git a/clang/test/Modules/ModuleDebugInfo.cpp b/clang/test/Modules/ModuleDebugInfo.cpp
index 71b05e5..008b3e4 100644 (file)
--- a/clang/test/Modules/ModuleDebugInfo.cpp
+++ b/clang/test/Modules/ModuleDebugInfo.cpp
@@ -86,10 +86,10 @@
 // CHECK-SAME:             flags: DIFlagFwdDecl
 // CHECK-SAME:             identifier: "_ZTSN8DebugCXX8TemplateIfNS_6traitsIfEEEE")
 
-// CHECK: !DICompositeType(tag: DW_TAG_class_type, name: "FwdVirtual"
+// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "Virtual"
 // CHECK-SAME:             elements:
-// CHECK-SAME:             identifier: "_ZTS10FwdVirtual")
-// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "_vptr$FwdVirtual"
+// CHECK-SAME:             identifier: "_ZTS7Virtual")
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "_vptr$Virtual"
 
 // CHECK: !DICompositeType(tag: DW_TAG_union_type,
 // CHECK-NOT:              name:
@@ -111,6 +111,11 @@
 // CHECK-SAME:             name: "InAnonymousNamespace",
 // CHECK-SAME:             elements: !{{[0-9]+}})
 
+// CHECK: ![[A:.*]] = {{.*}}!DICompositeType(tag: DW_TAG_class_type, name: "A",
+// CHECK-SAME:                               elements:
+// CHECK-SAME:                               vtableHolder: ![[A]],
+// CHECK-SAME:                               identifier: "_ZTS1A")
+
 // CHECK: ![[DERIVED:.*]] = {{.*}}!DICompositeType(tag: DW_TAG_class_type, name: "Derived",
 // CHECK-SAME:                                     identifier: "_ZTS7Derived")
 // CHECK: !DICompositeType(tag: DW_TAG_class_type, name: "B", scope: ![[DERIVED]],