caio/clang-p2996
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Reland "[lldb][DWARF] Remove object_pointer from ParsedDWARFAttributes (#145065)" (#145126)

Browse Source 
This reverts commit 877511920d.

This fixes the `TestObjCInBlockVars.py` LLDB API test.

The issue was that `GetCXXObjectParameter` wouldn't deduce the object
parameter of Objective-C method definitions correctly. In DWARF those
don't have a `DW_AT_specification` (so no link back to a DeclContext
that is a class type). The fix is to only check the validity of the
DeclContext DIE *if* no `DW_AT_object_pointer` exists on the DIE. If
`DW_AT_object_pointer` does exist, we should just always use that as the
object_parameter.
This commit is contained in:
Michael Buch
2025-06-23 17:26:23 +01:00
committed by GitHub
parent 634fe0de50
commit 5a16645a3d
3 changed files with 176 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files

35
lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
View File

@@ -167,9 +167,6 @@ DWARFASTParserClang::GetObjectParameter(const DWARFDIE &subprogram,
subprogram.Tag() == DW_TAG_inlined_subroutine ||
subprogram.Tag() == DW_TAG_subroutine_type);
if (!decl_ctx_die.IsStructUnionOrClass())
return {};
if (DWARFDIE object_parameter =
subprogram.GetAttributeValueAsReferenceDIE(DW_AT_object_pointer))
return object_parameter;
@@ -177,6 +174,10 @@ DWARFASTParserClang::GetObjectParameter(const DWARFDIE &subprogram,
// If no DW_AT_object_pointer was specified, assume the implicit object
// parameter is the first parameter to the function, is called "this" and is
// artificial (which is what most compilers would generate).
if (!decl_ctx_die.IsStructUnionOrClass())
return {};
auto children = subprogram.children();
auto it = llvm::find_if(children, [](const DWARFDIE &child) {
return child.Tag() == DW_TAG_formal_parameter;
@@ -441,15 +442,6 @@ ParsedDWARFTypeAttributes::ParsedDWARFTypeAttributes(const DWARFDIE &die) {
name.SetCString(form_value.AsCString());
break;
case DW_AT_object_pointer:
// GetAttributes follows DW_AT_specification.
// DW_TAG_subprogram definitions and declarations may both
// have a DW_AT_object_pointer. Don't overwrite the one
// we parsed for the definition with the one from the declaration.
if (!object_pointer.IsValid())
object_pointer = form_value.Reference();
break;
case DW_AT_signature:
signature = form_value;
break;
@@ -1112,7 +1104,7 @@ bool DWARFASTParserClang::ParseObjCMethod(
std::pair<bool, TypeSP> DWARFASTParserClang::ParseCXXMethod(
const DWARFDIE &die, CompilerType clang_type,
const ParsedDWARFTypeAttributes &attrs, const DWARFDIE &decl_ctx_die,
bool is_static, bool &ignore_containing_context) {
const DWARFDIE &object_parameter, bool &ignore_containing_context) {
Log *log = GetLog(DWARFLog::TypeCompletion | DWARFLog::Lookups);
SymbolFileDWARF *dwarf = die.GetDWARF();
assert(dwarf);
@@ -1196,6 +1188,9 @@ std::pair<bool, TypeSP> DWARFASTParserClang::ParseCXXMethod(
TypeSystemClang::GetDeclContextForType(class_opaque_type), die,
attrs.name.GetCString());
// In DWARF, a C++ method is static if it has no object parameter child.
const bool is_static = !object_parameter.IsValid();
// We have a C++ member function with no children (this pointer!) and clang
// will get mad if we try and make a function that isn't well formed in the
// DWARF, so we will just skip it...
@@ -1221,9 +1216,7 @@ std::pair<bool, TypeSP> DWARFASTParserClang::ParseCXXMethod(
ClangASTMetadata metadata;
metadata.SetUserID(die.GetID());
char const *object_pointer_name =
attrs.object_pointer ? attrs.object_pointer.GetName() : nullptr;
if (object_pointer_name) {
if (char const *object_pointer_name = object_parameter.GetName()) {
metadata.SetObjectPtrName(object_pointer_name);
LLDB_LOGF(log, "Setting object pointer name: %s on method object %p.\n",
object_pointer_name, static_cast<void *>(cxx_method_decl));
@@ -1319,11 +1312,9 @@ DWARFASTParserClang::ParseSubroutine(const DWARFDIE &die,
type_handled =
ParseObjCMethod(*objc_method, die, clang_type, attrs, is_variadic);
} else if (is_cxx_method) {
// In DWARF, a C++ method is static if it has no object parameter child.
const bool is_static = !object_parameter.IsValid();
auto [handled, type_sp] =
ParseCXXMethod(die, clang_type, attrs, decl_ctx_die, is_static,
ignore_containing_context);
ParseCXXMethod(die, clang_type, attrs, decl_ctx_die,
object_parameter, ignore_containing_context);
if (type_sp)
return type_sp;
@@ -1418,9 +1409,7 @@ DWARFASTParserClang::ParseSubroutine(const DWARFDIE &die,
ClangASTMetadata metadata;
metadata.SetUserID(die.GetID());
char const *object_pointer_name =
attrs.object_pointer ? attrs.object_pointer.GetName() : nullptr;
if (object_pointer_name) {
if (char const *object_pointer_name = object_parameter.GetName()) {
metadata.SetObjectPtrName(object_pointer_name);
LLDB_LOGF(log,
"Setting object pointer name: %s on function "

7
lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h
View File

@@ -480,7 +480,8 @@ private:
/// \param[in] decl_ctx_die The DIE representing the DeclContext of the C++
/// method being parsed.
///
/// \param[in] is_static Is true iff we're parsing a static method.
/// \param[in] object_parameter The DIE of this subprogram's object parameter.
/// May be an invalid DIE for C++ static methods.
///
/// \param[out] ignore_containing_context Will get set to true if the caller
/// should treat this C++ method as-if it was not a C++ method.
@@ -495,7 +496,8 @@ private:
lldb_private::CompilerType clang_type,
const ParsedDWARFTypeAttributes &attrs,
const lldb_private::plugin::dwarf::DWARFDIE &decl_ctx_die,
bool is_static, bool &ignore_containing_context);
const lldb_private::plugin::dwarf::DWARFDIE &object_parameter,
bool &ignore_containing_context);
lldb::TypeSP ParseArrayType(const lldb_private::plugin::dwarf::DWARFDIE &die,
const ParsedDWARFTypeAttributes &attrs);
@@ -565,7 +567,6 @@ struct ParsedDWARFTypeAttributes {
const char *mangled_name = nullptr;
lldb_private::ConstString name;
lldb_private::Declaration decl;
lldb_private::plugin::dwarf::DWARFDIE object_pointer;
lldb_private::plugin::dwarf::DWARFFormValue abstract_origin;
lldb_private::plugin::dwarf::DWARFFormValue containing_type;
lldb_private::plugin::dwarf::DWARFFormValue signature;

162
lldb/unittests/SymbolFile/DWARF/DWARFASTParserClangTests.cpp
View File

@@ -742,8 +742,8 @@ DWARF:
ASSERT_EQ(type_sp, reparsed_type_sp);
}
TEST_F(DWARFASTParserClangTests, TestParseDWARFAttributes_ObjectPointer) {
// This tests the behaviour of ParsedDWARFTypeAttributes
TEST_F(DWARFASTParserClangTests, TestObjectPointer) {
// This tests the behaviour of DWARFASTParserClang
// for DW_TAG_subprogram definitions which have a DW_AT_object_pointer
// *and* a DW_AT_specification that also has a DW_AT_object_pointer.
// We don't want the declaration DW_AT_object_pointer to overwrite the
@@ -916,6 +916,164 @@ DWARF:
}
}
TEST_F(DWARFASTParserClangTests,
TestObjectPointer_NoSpecificationOnDefinition) {
// This tests the behaviour of DWARFASTParserClang
// for DW_TAG_subprogram definitions which have a DW_AT_object_pointer
// but no DW_AT_specification that would link back to its declaration.
// This is how Objective-C class method definitions are emitted.
const char *yamldata = R"(
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_EXEC
Machine: EM_AARCH64
DWARF:
debug_str:
- Context
- func
- this
debug_abbrev:
- ID: 0
Table:
- Code: 0x1
Tag: DW_TAG_compile_unit
Children: DW_CHILDREN_yes
Attributes:
- Attribute: DW_AT_language
Form: DW_FORM_data2
- Code: 0x2
Tag: DW_TAG_structure_type
Children: DW_CHILDREN_yes
Attributes:
- Attribute: DW_AT_name
Form: DW_FORM_strp
- Code: 0x3
Tag: DW_TAG_subprogram
Children: DW_CHILDREN_yes
Attributes:
- Attribute: DW_AT_name
Form: DW_FORM_strp
- Attribute: DW_AT_declaration
Form: DW_FORM_flag_present
- Attribute: DW_AT_object_pointer
Form: DW_FORM_ref4
- Attribute: DW_AT_artificial
Form: DW_FORM_flag_present
- Attribute: DW_AT_external
Form: DW_FORM_flag_present
- Code: 0x4
Tag: DW_TAG_formal_parameter
Children: DW_CHILDREN_no
Attributes:
- Attribute: DW_AT_artificial
Form: DW_FORM_flag_present
- Code: 0x5
Tag: DW_TAG_subprogram
Children: DW_CHILDREN_yes
Attributes:
- Attribute: DW_AT_object_pointer
Form: DW_FORM_ref4
- Code: 0x6
Tag: DW_TAG_formal_parameter
Children: DW_CHILDREN_no
Attributes:
- Attribute: DW_AT_name
Form: DW_FORM_strp
- Attribute: DW_AT_artificial
Form: DW_FORM_flag_present
debug_info:
- Version: 5
UnitType: DW_UT_compile
AddrSize: 8
Entries:
# DW_TAG_compile_unit
# DW_AT_language [DW_FORM_data2] (DW_LANG_C_plus_plus)
- AbbrCode: 0x1
Values:
- Value: 0x04
# DW_TAG_structure_type
# DW_AT_name [DW_FORM_strp] ("Context")
- AbbrCode: 0x2
Values:
- Value: 0x0
# DW_TAG_subprogram
# DW_AT_name [DW_FORM_strp] ("func")
# DW_AT_object_pointer [DW_FORM_ref4]
- AbbrCode: 0x3
Values:
- Value: 0x8
- Value: 0x1
- Value: 0x1d
- Value: 0x1
- Value: 0x1
# DW_TAG_formal_parameter
# DW_AT_artificial
- AbbrCode: 0x4
Values:
- Value: 0x1
- AbbrCode: 0x0
- AbbrCode: 0x0
# DW_TAG_subprogram
# DW_AT_object_pointer [DW_FORM_ref4] ("this")
- AbbrCode: 0x5
Values:
- Value: 0x25
# DW_TAG_formal_parameter
# DW_AT_name [DW_FORM_strp] ("this")
# DW_AT_artificial
- AbbrCode: 0x6
Values:
- Value: 0xd
- Value: 0x1
- AbbrCode: 0x0
- AbbrCode: 0x0
...
)";
YAMLModuleTester t(yamldata);
DWARFUnit *unit = t.GetDwarfUnit();
ASSERT_NE(unit, nullptr);
const DWARFDebugInfoEntry *cu_entry = unit->DIE().GetDIE();
ASSERT_EQ(cu_entry->Tag(), DW_TAG_compile_unit);
ASSERT_EQ(unit->GetDWARFLanguageType(), DW_LANG_C_plus_plus);
DWARFDIE cu_die(unit, cu_entry);
auto holder = std::make_unique<clang_utils::TypeSystemClangHolder>("ast");
auto &ast_ctx = *holder->GetAST();
DWARFASTParserClangStub ast_parser(ast_ctx);
auto context_die = cu_die.GetFirstChild();
ASSERT_TRUE(context_die.IsValid());
ASSERT_EQ(context_die.Tag(), DW_TAG_structure_type);
auto subprogram_definition = context_die.GetSibling();
ASSERT_TRUE(subprogram_definition.IsValid());
ASSERT_EQ(subprogram_definition.Tag(), DW_TAG_subprogram);
ASSERT_FALSE(subprogram_definition.GetAttributeValueAsOptionalUnsigned(
DW_AT_external));
ASSERT_FALSE(
subprogram_definition.GetAttributeValueAsReferenceDIE(DW_AT_specification)
.IsValid());
auto param_die = subprogram_definition.GetFirstChild();
ASSERT_TRUE(param_die.IsValid());
EXPECT_EQ(param_die,
ast_parser.GetObjectParameter(subprogram_definition, {}));
}
TEST_F(DWARFASTParserClangTests, TestParseSubroutine_ExplicitObjectParameter) {
// Tests parsing of a C++ non-static member function with an explicit object
// parameter that isn't called "this" and is not a pointer (but a CV-qualified