[Lldb-commits] [lldb] 7e00e3a - [lldb] Fix lookup of types in anonymous namespaces with -gsimple-template-names (#123054)

via lldb-commits lldb-commits at lists.llvm.org
Thu Jan 16 01:49:54 PST 2025


Author: Pavel Labath
Date: 2025-01-16T10:49:51+01:00
New Revision: 7e00e3ae6dd4ba215dad27d1729df533cbb37795

URL: https://github.com/llvm/llvm-project/commit/7e00e3ae6dd4ba215dad27d1729df533cbb37795
DIFF: https://github.com/llvm/llvm-project/commit/7e00e3ae6dd4ba215dad27d1729df533cbb37795.diff

LOG: [lldb] Fix lookup of types in anonymous namespaces with -gsimple-template-names (#123054)

Anonymous namespaces are supposed to be optional when looking up types.
This was not working in combination with -gsimple-template-names,
because the way it was constructing the complete (with template args)
name scope (i.e., by generating thescope as a string and then reparsing
it) did not preserve the information about the scope kinds.

Essentially what the code wants here is to call `GetTypeLookupContext`
(that's the function used to get the context in the "regular" code
path), but to embelish each name with the template arguments (if they
don't have them already). This PR implements exactly that by adding an
argument to control which kind of names are we interested in. This
should also make the lookup faster as it avoids parsing of the long
string, but I haven't attempted to benchmark that.

I believe this function can also be used in some other places where
we're manually appending template names, but I'm leaving that for
another patch.

Added: 
    

Modified: 
    lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.cpp
    lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.h
    lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
    lldb/test/API/lang/cpp/nested-template/TestNestedTemplate.py
    lldb/test/API/lang/cpp/nested-template/main.cpp

Removed: 
    


################################################################################
diff  --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.cpp
index 6857878b354a05..1e2564cb22f25e 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.cpp
@@ -19,6 +19,8 @@
 #include "llvm/ADT/iterator.h"
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
+#include "llvm/DebugInfo/DWARF/DWARFTypePrinter.h"
+#include "llvm/Support/raw_ostream.h"
 
 using namespace lldb_private;
 using namespace lldb_private::dwarf;
@@ -376,7 +378,8 @@ lldb_private::Type *DWARFDIE::ResolveTypeUID(const DWARFDIE &die) const {
   return nullptr;
 }
 
-static CompilerContext GetContextEntry(DWARFDIE die) {
+static CompilerContext GetContextEntry(DWARFDIE die,
+                                       bool derive_template_names) {
   auto ctx = [die](CompilerContextKind kind) {
     return CompilerContext(kind, ConstString(die.GetName()));
   };
@@ -386,11 +389,6 @@ static CompilerContext GetContextEntry(DWARFDIE die) {
     return ctx(CompilerContextKind::Module);
   case DW_TAG_namespace:
     return ctx(CompilerContextKind::Namespace);
-  case DW_TAG_class_type:
-  case DW_TAG_structure_type:
-    return ctx(CompilerContextKind::ClassOrStruct);
-  case DW_TAG_union_type:
-    return ctx(CompilerContextKind::Union);
   case DW_TAG_enumeration_type:
     return ctx(CompilerContextKind::Enum);
   case DW_TAG_subprogram:
@@ -401,12 +399,28 @@ static CompilerContext GetContextEntry(DWARFDIE die) {
     return ctx(CompilerContextKind::Typedef);
   case DW_TAG_base_type:
     return ctx(CompilerContextKind::Builtin);
+  case DW_TAG_class_type:
+  case DW_TAG_structure_type:
+  case DW_TAG_union_type: {
+    CompilerContextKind kind = die.Tag() == DW_TAG_union_type
+                                   ? CompilerContextKind::Union
+                                   : CompilerContextKind::ClassOrStruct;
+    llvm::StringRef name = die.GetName();
+    if (!derive_template_names || name.contains('<'))
+      return CompilerContext(kind, ConstString(name));
+
+    std::string name_storage = name.str();
+    llvm::raw_string_ostream os(name_storage);
+    llvm::DWARFTypePrinter<DWARFDIE>(os).appendAndTerminateTemplateParameters(
+        die);
+    return CompilerContext(kind, ConstString(os.str()));
+  }
   default:
     llvm_unreachable("Check tag type in the caller!");
   }
 }
 
-static void GetDeclContextImpl(DWARFDIE die,
+static void GetDeclContextImpl(DWARFDIE die, bool derive_template_names,
                                llvm::SmallSet<lldb::user_id_t, 4> &seen,
                                std::vector<CompilerContext> &context) {
   // Stop if we hit a cycle.
@@ -428,7 +442,7 @@ static void GetDeclContextImpl(DWARFDIE die,
     case DW_TAG_subprogram:
     case DW_TAG_variable:
     case DW_TAG_typedef:
-      context.push_back(GetContextEntry(die));
+      context.push_back(GetContextEntry(die, derive_template_names));
       break;
     default:
       break;
@@ -438,15 +452,16 @@ static void GetDeclContextImpl(DWARFDIE die,
   }
 }
 
-std::vector<CompilerContext> DWARFDIE::GetDeclContext() const {
+std::vector<CompilerContext>
+DWARFDIE::GetDeclContext(bool derive_template_names) const {
   llvm::SmallSet<lldb::user_id_t, 4> seen;
   std::vector<CompilerContext> context;
-  GetDeclContextImpl(*this, seen, context);
+  GetDeclContextImpl(*this, derive_template_names, seen, context);
   std::reverse(context.begin(), context.end());
   return context;
 }
 
-static void GetTypeLookupContextImpl(DWARFDIE die,
+static void GetTypeLookupContextImpl(DWARFDIE die, bool derive_template_names,
                                      llvm::SmallSet<lldb::user_id_t, 4> &seen,
                                      std::vector<CompilerContext> &context) {
   // Stop if we hit a cycle.
@@ -461,7 +476,7 @@ static void GetTypeLookupContextImpl(DWARFDIE die,
     case DW_TAG_variable:
     case DW_TAG_typedef:
     case DW_TAG_base_type:
-      context.push_back(GetContextEntry(die));
+      context.push_back(GetContextEntry(die, derive_template_names));
       break;
 
     // If any of the tags below appear in the parent chain, stop the decl
@@ -484,10 +499,11 @@ static void GetTypeLookupContextImpl(DWARFDIE die,
   }
 }
 
-std::vector<CompilerContext> DWARFDIE::GetTypeLookupContext() const {
+std::vector<CompilerContext>
+DWARFDIE::GetTypeLookupContext(bool derive_template_names) const {
   llvm::SmallSet<lldb::user_id_t, 4> seen;
   std::vector<CompilerContext> context;
-  GetTypeLookupContextImpl(*this, seen, context);
+  GetTypeLookupContextImpl(*this, derive_template_names, seen, context);
   std::reverse(context.begin(), context.end());
   return context;
 }

diff  --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.h
index c3239b5b121f94..8785ac09b1f145 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.h
@@ -73,7 +73,15 @@ class DWARFDIE : public DWARFBaseDIE {
   /// Return this DIE's decl context as it is needed to look up types
   /// in Clang modules. This context will include any modules or functions that
   /// the type is declared in so an exact module match can be efficiently made.
-  std::vector<CompilerContext> GetDeclContext() const;
+  ///
+  /// \param[in] derive_template_names
+  ///   If true, augments the returned names with template arguments derived
+  ///   from the child DIEs, if the names don't contained template arguments
+  ///   already. If false, the returned context will contain the names exactly
+  ///   as they are spelled in the debug info, regardless of whether that
+  ///   includes template arguments or not.
+  std::vector<CompilerContext>
+  GetDeclContext(bool derive_template_names = false) const;
 
   /// Get a context to a type so it can be looked up.
   ///
@@ -85,7 +93,15 @@ class DWARFDIE : public DWARFBaseDIE {
   /// appropriate time, like either the translation unit or at a function
   /// context. This is designed to allow users to efficiently look for types
   /// using a full or partial CompilerContext array.
-  std::vector<CompilerContext> GetTypeLookupContext() const;
+  ///
+  /// \param[in] derive_template_names
+  ///   If true, augments the returned names with template arguments derived
+  ///   from the child DIEs, if the names don't contained template arguments
+  ///   already. If false, the returned context will contain the names exactly
+  ///   as they are spelled in the debug info, regardless of whether that
+  ///   includes template arguments or not.
+  std::vector<CompilerContext>
+  GetTypeLookupContext(bool derive_template_names = false) const;
 
   DWARFDeclContext GetDWARFDeclContext() const;
 

diff  --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
index 360dbaa1beb5eb..2f451d173c4dd0 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -10,10 +10,8 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
-#include "llvm/DebugInfo/DWARF/DWARFTypePrinter.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/FileUtilities.h"
-#include "llvm/Support/Format.h"
 #include "llvm/Support/FormatAdapters.h"
 #include "llvm/Support/Threading.h"
 
@@ -2740,18 +2738,11 @@ 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.
-        }
-
-        std::string qualified_name;
-        llvm::raw_string_ostream os(qualified_name);
-        llvm::DWARFTypePrinter<DWARFDIE> type_printer(os);
-        type_printer.appendQualifiedName(die);
-        TypeQuery die_query(qualified_name, e_exact_match);
-        if (query.ContextMatches(die_query.GetContextRef()))
+        std::vector<CompilerContext> qualified_context =
+            query.GetModuleSearch()
+                ? die.GetDeclContext(/*derive_template_names=*/true)
+                : die.GetTypeLookupContext(/*derive_template_names=*/true);
+        if (query.ContextMatches(qualified_context))
           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.

diff  --git a/lldb/test/API/lang/cpp/nested-template/TestNestedTemplate.py b/lldb/test/API/lang/cpp/nested-template/TestNestedTemplate.py
index 42db060529a818..055a8e6e210426 100644
--- a/lldb/test/API/lang/cpp/nested-template/TestNestedTemplate.py
+++ b/lldb/test/API/lang/cpp/nested-template/TestNestedTemplate.py
@@ -17,6 +17,16 @@ def do_test(self, debug_flags):
             DATA_TYPES_DISPLAYED_CORRECTLY,
             substrs=["1 match found"],
         )
+        self.expect(
+            "image lookup -A -t 'NS::Struct<int>'",
+            DATA_TYPES_DISPLAYED_CORRECTLY,
+            substrs=["1 match found"],
+        )
+        self.expect(
+            "image lookup -A -t 'NS::Union<int>'",
+            DATA_TYPES_DISPLAYED_CORRECTLY,
+            substrs=["1 match found"],
+        )
 
     @skipIf(compiler=no_match("clang"))
     @skipIf(compiler_version=["<", "15.0"])

diff  --git a/lldb/test/API/lang/cpp/nested-template/main.cpp b/lldb/test/API/lang/cpp/nested-template/main.cpp
index 06d1094880964c..9bef73052825fe 100644
--- a/lldb/test/API/lang/cpp/nested-template/main.cpp
+++ b/lldb/test/API/lang/cpp/nested-template/main.cpp
@@ -5,6 +5,15 @@ struct Outer {
   struct Inner {};
 };
 
+namespace NS {
+namespace {
+template <typename T> struct Struct {};
+template <typename T> struct Union {};
+} // namespace
+} // namespace NS
+
 int main() {
   Outer::Inner<int> oi;
+  NS::Struct<int> ns_struct;
+  NS::Union<int> ns_union;
 }


        


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