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[WIP][lldb][DWARFASTParserClang] Eagerly search definitions for Objective-C classes #119860

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[WIP][lldb][DWARFASTParserClang] Eagerly search definitions for Objective-C classes #119860

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103 changes: 73 additions & 30 deletions lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1671,43 +1671,84 @@ DWARFASTParserClang::ParseStructureLikeDIE(const SymbolContext &sc,
attrs.is_forward_declaration = true;
}

DWARFDIE def_die;
if (attrs.is_forward_declaration && cu_language == eLanguageTypeObjC) {
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This is pretty much copied from ParseEnum

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You'd also need to check for eLanguageTypeObjCPlusPlus here.

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Would also be helpful to add a comment explaining why this block exists.

def_die = dwarf->FindDefinitionDIE(die);

if (!def_die) {
SymbolFileDWARFDebugMap *debug_map_symfile = dwarf->GetDebugMapSymfile();
if (debug_map_symfile) {
// We weren't able to find a full declaration in this DWARF,
// see if we have a declaration anywhere else...
def_die = debug_map_symfile->FindDefinitionDIE(die);
}
}

if (log) {
dwarf->GetObjectFile()->GetModule()->LogMessage(
log,
"SymbolFileDWARF({0:p}) - {1:x16}}: {2} ({3}) type \"{4}\" is a "
"forward declaration, complete DIE is {5}",
static_cast<void *>(this), die.GetID(), DW_TAG_value_to_name(tag),
tag, attrs.name.GetCString(),
def_die ? llvm::utohexstr(def_die.GetID()) : "not found");
}

if (def_die) {
if (auto [it, inserted] = dwarf->GetDIEToType().try_emplace(
def_die.GetDIE(), DIE_IS_BEING_PARSED);
!inserted) {
if (it->getSecond() == nullptr ||
it->getSecond() == DIE_IS_BEING_PARSED)
return nullptr;
return it->getSecond()->shared_from_this();
}
attrs = ParsedDWARFTypeAttributes(def_die);
}
}

if (!def_die)
def_die = die;

if (attrs.name) {
GetUniqueTypeNameAndDeclaration(die, cu_language, unique_typename,
GetUniqueTypeNameAndDeclaration(def_die, cu_language, unique_typename,
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I find the name def_die misleading here. IIUC, it may be a def die if the block above was run and successful?

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+1, for non-objc/objc++ cases, the parameter die could be a def die or decl die. Maybe move def_die into the above block and update the parameter die to def_die if def_die is valid.

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The only catch there is that then die needs to be a value parameter, but I think that's a fine tradeoff. I contemplated doing that in #96484 (which is where the def_die name comes from, I think), and I didn't do it only because knew (well, I thought I knew) that code was going to be temporary).

unique_decl);
if (log) {
dwarf->GetObjectFile()->GetModule()->LogMessage(
log, "SymbolFileDWARF({0:p}) - {1:x16}: {2} has unique name: {3} ",
static_cast<void *>(this), die.GetID(), DW_TAG_value_to_name(tag),
static_cast<void *>(this), def_die.GetID(), DW_TAG_value_to_name(tag),
unique_typename.AsCString());
}
if (UniqueDWARFASTType *unique_ast_entry_type =
dwarf->GetUniqueDWARFASTTypeMap().Find(
unique_typename, die, unique_decl, byte_size,
unique_typename, def_die, unique_decl, byte_size,
attrs.is_forward_declaration)) {
if (TypeSP type_sp = unique_ast_entry_type->m_type_sp) {
dwarf->GetDIEToType()[die.GetDIE()] = type_sp.get();
dwarf->GetDIEToType()[def_die.GetDIE()] = type_sp.get();
LinkDeclContextToDIE(
GetCachedClangDeclContextForDIE(unique_ast_entry_type->m_die), die);
GetCachedClangDeclContextForDIE(unique_ast_entry_type->m_die),
def_die);
// If the DIE being parsed in this function is a definition and the
// entry in the map is a declaration, then we need to update the entry
// to point to the definition DIE.
if (!attrs.is_forward_declaration &&
unique_ast_entry_type->m_is_forward_declaration) {
unique_ast_entry_type->UpdateToDefDIE(die, unique_decl, byte_size);
unique_ast_entry_type->UpdateToDefDIE(def_die, unique_decl,
byte_size);
clang_type = type_sp->GetForwardCompilerType();

CompilerType compiler_type_no_qualifiers =
ClangUtil::RemoveFastQualifiers(clang_type);
dwarf->GetForwardDeclCompilerTypeToDIE().insert_or_assign(
compiler_type_no_qualifiers.GetOpaqueQualType(),
*die.GetDIERef());
*def_die.GetDIERef());
}
return type_sp;
}
}
}

DEBUG_PRINTF("0x%8.8" PRIx64 ": %s (\"%s\")\n", die.GetID(),
DEBUG_PRINTF("0x%8.8" PRIx64 ": %s (\"%s\")\n", def_die.GetID(),
DW_TAG_value_to_name(tag), type_name_cstr);

int tag_decl_kind = -1;
Expand All @@ -1726,22 +1767,22 @@ DWARFASTParserClang::ParseStructureLikeDIE(const SymbolContext &sc,
if ((attrs.class_language == eLanguageTypeObjC ||
attrs.class_language == eLanguageTypeObjC_plus_plus) &&
!attrs.is_complete_objc_class &&
die.Supports_DW_AT_APPLE_objc_complete_type()) {
def_die.Supports_DW_AT_APPLE_objc_complete_type()) {
// We have a valid eSymbolTypeObjCClass class symbol whose name
// matches the current objective C class that we are trying to find
// and this DIE isn't the complete definition (we checked
// is_complete_objc_class above and know it is false), so the real
// definition is in here somewhere
TypeSP type_sp =
dwarf->FindCompleteObjCDefinitionTypeForDIE(die, attrs.name, true);
dwarf->FindCompleteObjCDefinitionTypeForDIE(def_die, attrs.name, true);

if (!type_sp) {
SymbolFileDWARFDebugMap *debug_map_symfile = dwarf->GetDebugMapSymfile();
if (debug_map_symfile) {
// We weren't able to find a full declaration in this DWARF,
// see if we have a declaration anywhere else...
type_sp = debug_map_symfile->FindCompleteObjCDefinitionTypeForDIE(
die, attrs.name, true);
def_die, attrs.name, true);
}
}

Expand All @@ -1751,8 +1792,9 @@ DWARFASTParserClang::ParseStructureLikeDIE(const SymbolContext &sc,
log,
"SymbolFileDWARF({0:p}) - {1:x16}: {2} ({3}) type \"{4}\" is an "
"incomplete objc type, complete type is {5:x8}",
static_cast<void *>(this), die.GetID(), DW_TAG_value_to_name(tag),
tag, attrs.name.GetCString(), type_sp->GetID());
static_cast<void *>(this), def_die.GetID(),
DW_TAG_value_to_name(tag), tag, attrs.name.GetCString(),
type_sp->GetID());
}
return type_sp;
}
Expand All @@ -1761,18 +1803,18 @@ DWARFASTParserClang::ParseStructureLikeDIE(const SymbolContext &sc,
if (attrs.is_forward_declaration) {
// See if the type comes from a Clang module and if so, track down
// that type.
TypeSP type_sp = ParseTypeFromClangModule(sc, die, log);
TypeSP type_sp = ParseTypeFromClangModule(sc, def_die, log);
if (type_sp)
return type_sp;
}

assert(tag_decl_kind != -1);
UNUSED_IF_ASSERT_DISABLED(tag_decl_kind);
clang::DeclContext *containing_decl_ctx =
GetClangDeclContextContainingDIE(die, nullptr);
GetClangDeclContextContainingDIE(def_die, nullptr);

PrepareContextToReceiveMembers(m_ast, GetClangASTImporter(),
containing_decl_ctx, die,
containing_decl_ctx, def_die,
attrs.name.GetCString());

if (attrs.accessibility == eAccessNone && containing_decl_ctx) {
Expand All @@ -1785,31 +1827,32 @@ DWARFASTParserClang::ParseStructureLikeDIE(const SymbolContext &sc,
}

ClangASTMetadata metadata;
metadata.SetUserID(die.GetID());
metadata.SetIsDynamicCXXType(dwarf->ClassOrStructIsVirtual(die));
metadata.SetUserID(def_die.GetID());
metadata.SetIsDynamicCXXType(dwarf->ClassOrStructIsVirtual(def_die));

TypeSystemClang::TemplateParameterInfos template_param_infos;
if (ParseTemplateParameterInfos(die, template_param_infos)) {
if (ParseTemplateParameterInfos(def_die, template_param_infos)) {
clang::ClassTemplateDecl *class_template_decl =
m_ast.ParseClassTemplateDecl(
containing_decl_ctx, GetOwningClangModule(die), attrs.accessibility,
attrs.name.GetCString(), tag_decl_kind, template_param_infos);
containing_decl_ctx, GetOwningClangModule(def_die),
attrs.accessibility, attrs.name.GetCString(), tag_decl_kind,
template_param_infos);
if (!class_template_decl) {
if (log) {
dwarf->GetObjectFile()->GetModule()->LogMessage(
log,
"SymbolFileDWARF({0:p}) - {1:x16}: {2} ({3}) type \"{4}\" "
"clang::ClassTemplateDecl failed to return a decl.",
static_cast<void *>(this), die.GetID(), DW_TAG_value_to_name(tag),
tag, attrs.name.GetCString());
static_cast<void *>(this), def_die.GetID(),
DW_TAG_value_to_name(tag), tag, attrs.name.GetCString());
}
return TypeSP();
}

clang::ClassTemplateSpecializationDecl *class_specialization_decl =
m_ast.CreateClassTemplateSpecializationDecl(
containing_decl_ctx, GetOwningClangModule(die), class_template_decl,
tag_decl_kind, template_param_infos);
containing_decl_ctx, GetOwningClangModule(def_die),
class_template_decl, tag_decl_kind, template_param_infos);
clang_type =
m_ast.CreateClassTemplateSpecializationType(class_specialization_decl);

Expand All @@ -1819,13 +1862,13 @@ DWARFASTParserClang::ParseStructureLikeDIE(const SymbolContext &sc,

if (!clang_type) {
clang_type = m_ast.CreateRecordType(
containing_decl_ctx, GetOwningClangModule(die), attrs.accessibility,
containing_decl_ctx, GetOwningClangModule(def_die), attrs.accessibility,
attrs.name.GetCString(), tag_decl_kind, attrs.class_language, metadata,
attrs.exports_symbols);
}

TypeSP type_sp = dwarf->MakeType(
die.GetID(), attrs.name, attrs.byte_size, nullptr, LLDB_INVALID_UID,
def_die.GetID(), attrs.name, attrs.byte_size, nullptr, LLDB_INVALID_UID,
Type::eEncodingIsUID, &attrs.decl, clang_type,
Type::ResolveState::Forward,
TypePayloadClang(OptionalClangModuleID(), attrs.is_complete_objc_class));
Expand All @@ -1835,7 +1878,7 @@ DWARFASTParserClang::ParseStructureLikeDIE(const SymbolContext &sc,
// function prototypes.
clang::DeclContext *type_decl_ctx =
TypeSystemClang::GetDeclContextForType(clang_type);
LinkDeclContextToDIE(type_decl_ctx, die);
LinkDeclContextToDIE(type_decl_ctx, def_die);

// UniqueDWARFASTType is large, so don't create a local variables on the
// stack, put it on the heap. This function is often called recursively and
Expand All @@ -1846,7 +1889,7 @@ DWARFASTParserClang::ParseStructureLikeDIE(const SymbolContext &sc,
// copies of the same type over and over in the ASTContext for our
// module
unique_ast_entry_up->m_type_sp = type_sp;
unique_ast_entry_up->m_die = die;
unique_ast_entry_up->m_die = def_die;
unique_ast_entry_up->m_declaration = unique_decl;
unique_ast_entry_up->m_byte_size = byte_size;
unique_ast_entry_up->m_is_forward_declaration = attrs.is_forward_declaration;
Expand All @@ -1862,7 +1905,7 @@ DWARFASTParserClang::ParseStructureLikeDIE(const SymbolContext &sc,
dwarf->GetForwardDeclCompilerTypeToDIE()
.try_emplace(
ClangUtil::RemoveFastQualifiers(clang_type).GetOpaqueQualType(),
*die.GetDIERef())
*def_die.GetDIERef())
.second;
assert(inserted && "Type already in the forward declaration map!");
(void)inserted;
Expand Down
33 changes: 33 additions & 0 deletions lldb/test/Shell/SymbolFile/DWARF/objc-gmodules-class-extension.test
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Original file line number Diff line number Diff line change
@@ -0,0 +1,33 @@
# REQUIRES: system-darwin

# Test that we can set a breakpoint in a method of a class extension.
# This requires us to parse the method into an AST type, and the context
# too (which in DWARF is just a forward declaration).
#
# RUN: split-file %s %t
# RUN: %clangxx_host %t/lib.m -c -g -gmodules -fmodules -o %t/lib.o
# RUN: %clangxx_host %t/main.m -g -gmodules -fmodules %t/lib.o -o %t/a.out -framework Foundation
#
# RUN: %lldb %t/a.out -o "breakpoint set -f lib.m -l 6" -o exit | FileCheck %s

# CHECK: (lldb) breakpoint set -f lib.m -l 6
# CHECK: Breakpoint 1: where = a.out`-[NSObject(Foo) func]

#--- main.m
int main() {
return 0;
}

#--- lib.m
#import <Foundation/Foundation.h>

@implementation NSObject (Foo)
- (NSError *)func {
NSLog(@"Hello, World!");
return 0;
}
@end

NSObject * func() {
return 0;
}
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