[Lldb-commits] [lldb] [lldb][DWARFASTParserClang] DWARFv5: support DW_TAG_variable static data members declarations (PR #72236)

[Michael Buch via lldb-commits]

https://github.com/Michael137 updated https://github.com/llvm/llvm-project/pull/72236

>From de2be505917256a03718a10928547730d03bc8bc Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Mon, 13 Nov 2023 08:13:08 +0000
Subject: [PATCH 1/2] [lldb][DWARFASTParserClang] DWARFv5: support
 DW_TAG_variable static data members

The accepted DWARFv5 issue 161118.1: "DW_TAG for C++ static data members"
specifies that static data member declaration be described
by DW_TAG_variable. Make sure we recognize such members.
---
 .../Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp      | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
index f5628b2753da2a7..79d3199855e1be7 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -144,7 +144,7 @@ static bool ShouldIgnoreArtificialField(llvm::StringRef FieldName) {
 
 std::optional<DWARFFormValue>
 DWARFASTParserClang::FindConstantOnVariableDefinition(DWARFDIE die) {
-  assert(die.Tag() == llvm::dwarf::DW_TAG_member);
+  assert(die.Tag() == DW_TAG_member || die.Tag() == DW_TAG_variable);
 
   auto *dwarf = die.GetDWARF();
   if (!dwarf)
@@ -2889,7 +2889,7 @@ void DWARFASTParserClang::CreateStaticMemberVariable(
     const DWARFDIE &die, const MemberAttributes &attrs,
     const lldb_private::CompilerType &class_clang_type) {
   Log *log = GetLog(DWARFLog::TypeCompletion | DWARFLog::Lookups);
-  assert(die.Tag() == DW_TAG_member);
+  assert(die.Tag() == DW_TAG_member || die.Tag() == DW_TAG_variable);
 
   Type *var_type = die.ResolveTypeUID(attrs.encoding_form.Reference());
 
@@ -3195,6 +3195,10 @@ bool DWARFASTParserClang::ParseChildMembers(
       }
       break;
 
+    case DW_TAG_variable: {
+      const MemberAttributes attrs(die, parent_die, module_sp);
+      CreateStaticMemberVariable(die, attrs, class_clang_type);
+    } break;
     case DW_TAG_member:
       ParseSingleMember(die, parent_die, class_clang_type,
                         default_accessibility, layout_info, last_field_info);

>From 85f9a63eacee3ce450177b48c4abb40e4cf1e897 Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Tue, 14 Nov 2023 10:33:41 +0000
Subject: [PATCH 2/2] fixup! add comment

---
 lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
index 79d3199855e1be7..37efe70461977ad 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -2965,6 +2965,7 @@ void DWARFASTParserClang::ParseSingleMember(
   // data members is DW_AT_declaration, so we check it instead.
   // FIXME: Since DWARFv5, static data members are marked DW_AT_variable so we
   // can consistently detect them on both GCC and Clang without below heuristic.
+  // Remove this block if we ever drop DWARFv4 support.
   if (attrs.member_byte_offset == UINT32_MAX &&
       attrs.data_bit_offset == UINT64_MAX && attrs.is_declaration) {
     CreateStaticMemberVariable(die, attrs, class_clang_type);