Merge pull request #2971 from Teemperor/cherry/34c697c85e9d

[lldb] Don't recursively load types of static member variables in the…

Author: Teemperor

lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp

@@ -2533,7 +2533,7 @@ void DWARFASTParserClang::ParseSingleMember(
       if (accessibility == eAccessNone)
         accessibility = eAccessPublic;
       TypeSystemClang::AddVariableToRecordType(
-          class_clang_type, name, var_type->GetLayoutCompilerType(),
+          class_clang_type, name, var_type->GetForwardCompilerType(),
           accessibility);
     }
     return;

lldb/test/API/functionalities/lazy-loading/TestLazyLoading.py

@@ -40,6 +40,7 @@ def setUp(self):
     class_in_namespace_decl = [class_decl_kind, "ClassInNamespace"]
     class_we_enter_decl = [class_decl_kind, "ClassWeEnter"]
     class_member_decl = [struct_decl_kind, "ClassMember"]
+    class_static_member_decl = [struct_decl_kind, "StaticClassMember"]
     unused_class_member_decl = [struct_decl_kind, "UnusedClassMember"]
     unused_class_member_ptr_decl = [struct_decl_kind, "UnusedClassMemberPtr"]
 
@@ -56,6 +57,7 @@ def assert_no_decls_loaded(self):
         self.assert_decl_not_loaded(self.other_struct_decl)
         self.assert_decl_not_loaded(self.class_in_namespace_decl)
         self.assert_decl_not_loaded(self.class_member_decl)
+        self.assert_decl_not_loaded(self.class_static_member_decl)
         self.assert_decl_not_loaded(self.unused_class_member_decl)
 
     def get_ast_dump(self):
@@ -228,6 +230,8 @@ def test_class_function_access_member(self):
         self.assert_decl_not_completed(self.unused_class_member_ptr_decl)
         # We loaded the member we used.
         self.assert_decl_loaded(self.class_member_decl)
+        # We didn't load the type of the unused static member.
+        self.assert_decl_not_completed(self.class_static_member_decl)
 
         # This should not have loaded anything else.
         self.assert_decl_not_loaded(self.other_struct_decl)

lldb/test/API/functionalities/lazy-loading/main.cpp

@@ -23,6 +23,7 @@ struct OtherStruct {
 // Class loading declarations.
 
 struct ClassMember { int i; };
+struct StaticClassMember { int i; };
 struct UnusedClassMember { int i; };
 struct UnusedClassMemberPtr { int i; };
 
@@ -34,12 +35,14 @@ class ClassWeEnter {
 public:
   int dummy; // Prevent bug where LLDB always completes first member.
   ClassMember member;
+  static StaticClassMember static_member;
   UnusedClassMember unused_member;
   UnusedClassMemberPtr *unused_member_ptr;
   int enteredFunction() {
     return member.i; // Location: class function
   }
 };
+StaticClassMember ClassWeEnter::static_member;
 };
 
 //----------------------------------------------------------------------------//

lldb/test/API/lang/cpp/static_member_type_depending_on_parent_size/Makefile

@@ -0,0 +1,3 @@
+CXX_SOURCES := main.cpp
+
+include Makefile.rules

lldb/test/API/lang/cpp/static_member_type_depending_on_parent_size/TestStaticMemberTypeDependingOnParentSize.py

@@ -0,0 +1,22 @@
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+class TestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    @no_debug_info_test
+    def test(self):
+        """
+        This tests a static member with a type which size depends on the
+        surrounding class. LLDB should *not* try to generate the record layout
+        for those types while parsing the members from debug info.
+        """
+        self.build()
+        self.dbg.CreateTarget(self.getBuildArtifact("a.out"))
+
+        # Force the record layout for 'ToLayout' to be generated by printing
+        # a value of it's type.
+        self.expect("target variable test_var")

lldb/test/API/lang/cpp/static_member_type_depending_on_parent_size/main.cpp

@@ -0,0 +1,28 @@
+// This class just serves as an indirection between LLDB and Clang. LLDB might
+// be tempted to check the member type of DependsOnParam2 for whether it's
+// in some 'currently-loading' state before trying to produce the record layout.
+// By inheriting from ToLayout this will make LLDB just check if
+// DependsOnParam1 is currently being loaded (which it's not) but it will
+template <typename ToLayoutParam> struct DependsOnParam1 : ToLayoutParam {};
+// This class forces the memory layout of it's type parameter to be created.
+template <typename ToLayoutParam> struct DependsOnParam2 {
+  DependsOnParam1<ToLayoutParam> m;
+};
+
+// This is the class that LLDB has to generate the record layout for.
+struct ToLayout {
+  // A static member variable which memory layout depends on the surrounding
+  // class. This comes first so that if we accidentially generate the layout
+  // for static member types we end up recursively going back to 'ToLayout'
+  // before 'some_member' has been loaded.
+  static DependsOnParam2<ToLayout> a_static_member;
+  // Some dummy member variable. This is only there so that Clang can detect
+  // that the record layout is inconsistent (i.e., the number of fields in the
+  // layout doesn't fit to the fields in the declaration).
+  int some_member;
+};
+DependsOnParam2<ToLayout> ToLayout::a_static_member;
+
+ToLayout test_var;
+
+int main() { return test_var.some_member; }