[Lldb-commits] [lldb] [lldb/DWARF] Remove duplicate type filtering (PR #116989)

[Pavel Labath via lldb-commits]

https://github.com/labath created https://github.com/llvm/llvm-project/pull/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.

>From aa1fde4817997d86a89086cb53092459a02e112b Mon Sep 17 00:00:00 2001
From: Pavel Labath <pavel at labath.sk>
Date: Wed, 20 Nov 2024 15:13:05 +0100
Subject: [PATCH] [lldb/DWARF] Remove duplicate type filtering

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.
---
 .../Plugins/SymbolFile/DWARF/DWARFIndex.cpp   | 14 ++++-
 .../SymbolFile/DWARF/SymbolFileDWARF.cpp      | 52 +------------------
 2 files changed, 14 insertions(+), 52 deletions(-)

diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFIndex.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFIndex.cpp
index c18edd10b96819..30c890d6d01388 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFIndex.cpp
+++ b/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())
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
index 8ce0db4588a46a..c900f330b481bb 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ b/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