1 files changed, 50 insertions, 17 deletions

diff --git a/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp b/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
index a7874047942c..6053d042b29b 100644
--- a/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
@@ -49,11 +49,6 @@ static void consumeInlineNamespace(llvm::StringRef &name) {
   }
 }
 
-bool lldb_private::formatters::isOldCompressedPairLayout(
-    ValueObject &pair_obj) {
-  return isStdTemplate(pair_obj.GetTypeName(), "__compressed_pair");
-}
-
 bool lldb_private::formatters::isStdTemplate(ConstString type_name,
                                              llvm::StringRef type) {
   llvm::StringRef name = type_name.GetStringRef();
@@ -105,6 +100,44 @@ lldb_private::formatters::GetSecondValueOfLibCXXCompressedPair(
   return value;
 }
 
+std::pair<lldb::ValueObjectSP, bool>
+lldb_private::formatters::GetValueOrOldCompressedPair(
+    ValueObject &obj, size_t anon_struct_idx, llvm::StringRef child_name,
+    llvm::StringRef compressed_pair_name) {
+  auto is_old_compressed_pair = [](ValueObject &pair_obj) -> bool {
+    return isStdTemplate(pair_obj.GetTypeName(), "__compressed_pair");
+  };
+
+  // Try searching the child member in an anonymous structure first.
+  if (auto unwrapped = obj.GetChildAtIndex(anon_struct_idx)) {
+    ValueObjectSP node_sp(obj.GetChildMemberWithName(child_name));
+    if (node_sp)
+      return {node_sp, is_old_compressed_pair(*node_sp)};
+  }
+
+  // Older versions of libc++ don't wrap the children in anonymous structures.
+  // Try that instead.
+  ValueObjectSP node_sp(obj.GetChildMemberWithName(child_name));
+  if (node_sp)
+    return {node_sp, is_old_compressed_pair(*node_sp)};
+
+  // Try the even older __compressed_pair layout.
+
+  assert(!compressed_pair_name.empty());
+
+  node_sp = obj.GetChildMemberWithName(compressed_pair_name);
+
+  // Unrecognized layout (possibly older than LLDB supports).
+  if (!node_sp)
+    return {nullptr, false};
+
+  // Expected old compressed_pair layout, but got something else.
+  if (!is_old_compressed_pair(*node_sp))
+    return {nullptr, false};
+
+  return {node_sp, true};
+}
+
 bool lldb_private::formatters::LibcxxFunctionSummaryProvider(
     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
 
@@ -205,11 +238,12 @@ bool lldb_private::formatters::LibcxxUniquePointerSummaryProvider(
   if (!valobj_sp)
     return false;
 
-  ValueObjectSP ptr_sp(valobj_sp->GetChildMemberWithName("__ptr_"));
+  auto [ptr_sp, is_compressed_pair] = GetValueOrOldCompressedPair(
+      *valobj_sp, /*anon_struct_idx=*/0, "__ptr_", "__ptr_");
   if (!ptr_sp)
     return false;
 
-  if (isOldCompressedPairLayout(*ptr_sp))
+  if (is_compressed_pair)
     ptr_sp = GetFirstValueOfLibCXXCompressedPair(*ptr_sp);
 
   if (!ptr_sp)
@@ -379,13 +413,14 @@ lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::Update() {
   if (!valobj_sp)
     return lldb::ChildCacheState::eRefetch;
 
-  ValueObjectSP ptr_sp(valobj_sp->GetChildMemberWithName("__ptr_"));
+  auto [ptr_sp, is_compressed_pair] = GetValueOrOldCompressedPair(
+      *valobj_sp, /*anon_struct_idx=*/0, "__ptr_", "__ptr_");
   if (!ptr_sp)
     return lldb::ChildCacheState::eRefetch;
 
   // Retrieve the actual pointer and the deleter, and clone them to give them
   // user-friendly names.
-  if (isOldCompressedPairLayout(*ptr_sp)) {
+  if (is_compressed_pair) {
     if (ValueObjectSP value_pointer_sp =
             GetFirstValueOfLibCXXCompressedPair(*ptr_sp))
       m_value_ptr_sp = value_pointer_sp->Clone(ConstString("pointer"));
@@ -424,17 +459,15 @@ enum class StringLayout { CSD, DSC };
 }
 
 static ValueObjectSP ExtractLibCxxStringData(ValueObject &valobj) {
-  if (auto rep_sp = valobj.GetChildMemberWithName("__rep_"))
-    return rep_sp;
-
-  ValueObjectSP valobj_r_sp = valobj.GetChildMemberWithName("__r_");
-  if (!valobj_r_sp || !valobj_r_sp->GetError().Success())
+  auto [valobj_r_sp, is_compressed_pair] = GetValueOrOldCompressedPair(
+      valobj, /*anon_struct_idx=*/0, "__rep_", "__r_");
+  if (!valobj_r_sp)
     return nullptr;
 
-  if (!isOldCompressedPairLayout(*valobj_r_sp))
-    return nullptr;
+  if (is_compressed_pair)
+    return GetFirstValueOfLibCXXCompressedPair(*valobj_r_sp);
 
-  return GetFirstValueOfLibCXXCompressedPair(*valobj_r_sp);
+  return valobj_r_sp;
 }
 
 /// Determine the size in bytes of \p valobj (a libc++ std::string object) and