[LLDB] Ignore actual-needed artificial members in DWARFASTParserClang::ParseSingleMember (#70779)

Address the FIXME, this will allow lldb to print all fields of the
generated coroutine frame structure.

Fixes #69309.

Author: hokein

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

@@ -133,6 +133,14 @@ static lldb::ModuleSP GetContainingClangModule(const DWARFDIE &die) {
   return lldb::ModuleSP();
 }
 
+// Returns true if the given artificial field name should be ignored when
+// parsing the DWARF.
+static bool ShouldIgnoreArtificialField(llvm::StringRef FieldName) {
+  return FieldName.starts_with("_vptr$")
+         // gdb emit vtable pointer as "_vptr.classname"
+         || FieldName.starts_with("_vptr.");
+}
+
 TypeSP DWARFASTParserClang::ParseTypeFromClangModule(const SymbolContext &sc,
                                                      const DWARFDIE &die,
                                                      Log *log) {
@@ -3059,9 +3067,7 @@ void DWARFASTParserClang::ParseSingleMember(
   // This needs to be done after updating FieldInfo which keeps track of where
   // field start/end so we don't later try to fill the space of this
   // artificial member with (unnamed bitfield) padding.
-  // FIXME: This check should verify that this is indeed an artificial member
-  // we are supposed to ignore.
-  if (attrs.is_artificial) {
+  if (attrs.is_artificial && ShouldIgnoreArtificialField(attrs.name)) {
     last_field_info.SetIsArtificial(true);
     return;
   }

lldb/test/Shell/SymbolFile/DWARF/ignored_artificial_fields.test

@@ -0,0 +1,17 @@
+# UNSUPPORTED: system-darwin, system-windows
+
+# Make sure the artifical field `vptr.ClassName` from gcc debug info is ignored.
+# RUN: %build --compiler=gcc %S/Inputs/debug-types-expressions.cpp -o %t
+# RUN: %lldb %t -s %s -o exit | FileCheck %s
+
+breakpoint set -n foo
+process launch
+
+# CHECK: Process {{.*}} stopped
+
+frame variable *a
+# CHECK-LABEL: frame variable *a
+# CHECK:      (B) *a = {
+# CHECK-NEXT:   A = (i = 47)
+# CHECK-NEXT:   j = 42
+# CHECK-NEXT: }