[Lldb-commits] [lldb] e439a46 - [lldb] Use forward type in pointer-to-member
Raphael Isemann via lldb-commits
lldb-commits at lists.llvm.org
Mon Apr 26 06:24:18 PDT 2021
Author: Emre Kultursay
Date: 2021-04-26T15:23:58+02:00
New Revision: e439a463a30833f1c7d366ed722f0f12d1682638
URL: https://github.com/llvm/llvm-project/commit/e439a463a30833f1c7d366ed722f0f12d1682638
DIFF: https://github.com/llvm/llvm-project/commit/e439a463a30833f1c7d366ed722f0f12d1682638.diff
LOG: [lldb] Use forward type in pointer-to-member
This change is similar in spirit to the change at:
https://reviews.llvm.org/rG34c697c85e9d0af11a72ac4df5578aac94a627b3
It fixes the problem where the layout of a type was being accessed
while its base classes were not populated yet; which caused an
incorrect layout to be produced and cached.
This fixes PR50054
Reviewed By: teemperor
Differential Revision: https://reviews.llvm.org/D100977
Added:
lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/Makefile
lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/TestPointerToMemberTypeDependingOnParentSize.py
lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/main.cpp
Modified:
lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
lldb/test/API/functionalities/lazy-loading/TestLazyLoading.py
lldb/test/API/functionalities/lazy-loading/main.cpp
Removed:
################################################################################
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
index c417f8055c88..55fd5897c370 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -1361,7 +1361,7 @@ TypeSP DWARFASTParserClang::ParsePointerToMemberType(
dwarf->ResolveTypeUID(attrs.containing_type.Reference(), true);
CompilerType pointee_clang_type = pointee_type->GetForwardCompilerType();
- CompilerType class_clang_type = class_type->GetLayoutCompilerType();
+ CompilerType class_clang_type = class_type->GetForwardCompilerType();
CompilerType clang_type = TypeSystemClang::CreateMemberPointerType(
class_clang_type, pointee_clang_type);
diff --git a/lldb/test/API/functionalities/lazy-loading/TestLazyLoading.py b/lldb/test/API/functionalities/lazy-loading/TestLazyLoading.py
index 326315c838e5..de5154e66ae5 100644
--- a/lldb/test/API/functionalities/lazy-loading/TestLazyLoading.py
+++ b/lldb/test/API/functionalities/lazy-loading/TestLazyLoading.py
@@ -41,6 +41,7 @@ def setUp(self):
class_we_enter_decl = [class_decl_kind, "ClassWeEnter"]
class_member_decl = [struct_decl_kind, "ClassMember"]
class_static_member_decl = [struct_decl_kind, "StaticClassMember"]
+ class_pointer_to_member_decl = [struct_decl_kind, "PointerToMember"]
unused_class_member_decl = [struct_decl_kind, "UnusedClassMember"]
unused_class_member_ptr_decl = [struct_decl_kind, "UnusedClassMemberPtr"]
@@ -58,6 +59,7 @@ def assert_no_decls_loaded(self):
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.class_pointer_to_member_decl)
self.assert_decl_not_loaded(self.unused_class_member_decl)
def get_ast_dump(self):
@@ -232,6 +234,8 @@ def test_class_function_access_member(self):
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)
+ # We didn't load the type of the unused pointer-to-member member.
+ self.assert_decl_not_completed(self.class_pointer_to_member_decl)
# This should not have loaded anything else.
self.assert_decl_not_loaded(self.other_struct_decl)
diff --git a/lldb/test/API/functionalities/lazy-loading/main.cpp b/lldb/test/API/functionalities/lazy-loading/main.cpp
index bb8f56e277ce..013fb02eb88f 100644
--- a/lldb/test/API/functionalities/lazy-loading/main.cpp
+++ b/lldb/test/API/functionalities/lazy-loading/main.cpp
@@ -26,6 +26,7 @@ struct ClassMember { int i; };
struct StaticClassMember { int i; };
struct UnusedClassMember { int i; };
struct UnusedClassMemberPtr { int i; };
+struct PointerToMember { int i; };
namespace NS {
class ClassInNamespace {
@@ -36,6 +37,7 @@ class ClassWeEnter {
int dummy; // Prevent bug where LLDB always completes first member.
ClassMember member;
static StaticClassMember static_member;
+ int (PointerToMember::*ptr_to_member);
UnusedClassMember unused_member;
UnusedClassMemberPtr *unused_member_ptr;
int enteredFunction() {
diff --git a/lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/Makefile b/lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/Makefile
new file mode 100644
index 000000000000..99998b20bcb0
--- /dev/null
+++ b/lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/Makefile
@@ -0,0 +1,3 @@
+CXX_SOURCES := main.cpp
+
+include Makefile.rules
diff --git a/lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/TestPointerToMemberTypeDependingOnParentSize.py b/lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/TestPointerToMemberTypeDependingOnParentSize.py
new file mode 100644
index 000000000000..fd978158e716
--- /dev/null
+++ b/lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/TestPointerToMemberTypeDependingOnParentSize.py
@@ -0,0 +1,24 @@
+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 pointer-to-member member which class part is the
+ surrounding class. LLDB should *not* try to generate the record layout
+ of the class when parsing pointer-to-member types while parsing debug
+ info (as the references class might not be complete when the type is
+ parsed).
+ """
+ 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")
diff --git a/lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/main.cpp b/lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/main.cpp
new file mode 100644
index 000000000000..4787691ac9f7
--- /dev/null
+++ b/lldb/test/API/lang/cpp/pointer_to_member_type_depending_on_parent_size/main.cpp
@@ -0,0 +1,35 @@
+// 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 won't
+// check if all the types DependsOnParam2 is depending on for its layout are
+// currently parsed.
+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 {
+ // The class part of this pointer-to-member type has a memory layout that
+ // depends on the surrounding class. If LLDB eagerly tries to layout the
+ // class part of a pointer-to-member type while parsing, then layouting this
+ // type should cause a test failure (as we aren't done parsing ToLayout
+ // at this point).
+ int DependsOnParam2<ToLayout>::* pointer_to_member_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;
+};
+
+// Emit the definition of DependsOnParam2<ToLayout>. It seems Clang won't
+// emit the definition of a class template if it's only used in the class part
+// of a pointer-to-member type.
+DependsOnParam2<ToLayout> x;
+
+ToLayout test_var;
+
+int main() { return test_var.some_member; }
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