[lldb/DWARF] Remove duplicate type filtering (#116989)

In #108907, the index classes started filtering the DIEs according to
the full type query (instead of just the base name). This means that the
checks in SymbolFileDWARF are now redundant.

I've also moved the non-redundant checks so that now all checking is
done in the DWARFIndex class and the caller can expect to get the final
filtered list of types.

Author: labath

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

@@ -137,9 +137,19 @@ void DWARFIndex::GetTypesWithQuery(
 bool DWARFIndex::ProcessTypeDIEMatchQuery(
     TypeQuery &query, DWARFDIE die,
     llvm::function_ref<bool(DWARFDIE die)> callback) {
-  // Nothing to match from query
-  if (query.GetContextRef().size() <= 1)
+  // Check the language, but only if we have a language filter.
+  if (query.HasLanguage() &&
+      !query.LanguageMatches(SymbolFileDWARF::GetLanguageFamily(*die.GetCU())))
+    return true; // Keep iterating over index types, language mismatch.
+
+  // Since mangled names are unique, we only need to check if the names are
+  // the same.
+  if (query.GetSearchByMangledName()) {
+    if (die.GetMangledName(/*substitute_name_allowed=*/false) !=
+        query.GetTypeBasename().GetStringRef())
+      return true; // Keep iterating over index types, mangled name mismatch.
     return callback(die);
+  }
 
   std::vector<lldb_private::CompilerContext> die_context;
   if (query.GetModuleSearch())

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

@@ -2726,39 +2726,8 @@ void SymbolFileDWARF::FindTypes(const TypeQuery &query, TypeResults &results) {
   TypeQuery query_full(query);
   bool have_index_match = false;
   m_index->GetTypesWithQuery(query_full, [&](DWARFDIE die) {
-    // Check the language, but only if we have a language filter.
-    if (query.HasLanguage()) {
-      if (!query.LanguageMatches(GetLanguageFamily(*die.GetCU())))
-        return true; // Keep iterating over index types, language mismatch.
-    }
-
-    // Since mangled names are unique, we only need to check if the names are
-    // the same.
-    if (query.GetSearchByMangledName()) {
-      if (die.GetMangledName(/*substitute_name_allowed=*/false) !=
-          query.GetTypeBasename().GetStringRef())
-        return true; // Keep iterating over index types, mangled name mismatch.
-      if (Type *matching_type = ResolveType(die, true, true)) {
-        results.InsertUnique(matching_type->shared_from_this());
-        return !results.Done(query); // Keep iterating if we aren't done.
-      }
-      return true; // Keep iterating over index types, weren't able to resolve
-                   // this type
-    }
-
-    // Check the context matches
-    std::vector<lldb_private::CompilerContext> die_context;
-    if (query.GetModuleSearch())
-      die_context = die.GetDeclContext();
-    else
-      die_context = die.GetTypeLookupContext();
-    assert(!die_context.empty());
-    if (!query.ContextMatches(die_context))
-      return true; // Keep iterating over index types, context mismatch.
-
-    // Try to resolve the type.
     if (Type *matching_type = ResolveType(die, true, true)) {
-      if (matching_type->IsTemplateType()) {
+      if (!query.GetSearchByMangledName() && matching_type->IsTemplateType()) {
         // We have to watch out for case where we lookup a type by basename and
         // it matches a template with simple template names. Like looking up
         // "Foo" and if we have simple template names then we will match
@@ -2790,7 +2759,7 @@ void SymbolFileDWARF::FindTypes(const TypeQuery &query, TypeResults &results) {
   // With -gsimple-template-names, a templated type's DW_AT_name will not
   // contain the template parameters. Try again stripping '<' and anything
   // after, filtering out entries with template parameters that don't match.
-  if (!have_index_match) {
+  if (!have_index_match && !query.GetSearchByMangledName()) {
     // Create a type matcher with a compiler context that is tuned for
     // -gsimple-template-names. We will use this for the index lookup and the
     // context matching, but will use the original "match" to insert matches
@@ -2804,23 +2773,6 @@ void SymbolFileDWARF::FindTypes(const TypeQuery &query, TypeResults &results) {
       // Copy our match's context and update the basename we are looking for
       // so we can use this only to compare the context correctly.
       m_index->GetTypesWithQuery(query_simple, [&](DWARFDIE die) {
-        // Check the language, but only if we have a language filter.
-        if (query.HasLanguage()) {
-          if (!query.LanguageMatches(GetLanguageFamily(*die.GetCU())))
-            return true; // Keep iterating over index types, language mismatch.
-        }
-
-        // Check the context matches
-        std::vector<lldb_private::CompilerContext> die_context;
-        if (query.GetModuleSearch())
-          die_context = die.GetDeclContext();
-        else
-          die_context = die.GetTypeLookupContext();
-        assert(!die_context.empty());
-        if (!query_simple.ContextMatches(die_context))
-          return true; // Keep iterating over index types, context mismatch.
-
-        // Try to resolve the type.
         if (Type *matching_type = ResolveType(die, true, true)) {
           ConstString name = matching_type->GetQualifiedName();
           // We have found a type that still might not match due to template