[Lldb-commits] [PATCH] D106355: [DWARF5] Only fallback to manual index if no entry was found

[Kim-Anh Tran via Phabricator via lldb-commits]

kimanh created this revision.
Herald added a subscriber: arphaman.
kimanh updated this revision to Diff 360084.
kimanh added a comment.
kimanh retitled this revision from "[Index] Only fallback to manual index if no entry was found" to "[DWARF5] Only fallback to manual index if no entry was found".
kimanh added a reviewer: labath.
kimanh added a subscriber: pfaffe.
kimanh published this revision for review.
Herald added a project: LLDB.
Herald added a subscriber: lldb-commits.

Minor: rename variable


kimanh added a comment.

Hello Pavel,

we are currently looking at the usage of the .debug_names section. For `DebugNamesDWARFIndex::GetGlobalVariables(DWARFUnit &cu, llvm::function_ref<bool(DWARFDIE die)> callback)` we do not see a clear reason why one would need to still call the fallback. In this case, we only look at that particular CU, and if there's already a name index for that CU, going through the name index should be enough? If we are missing something, please let us know! Otherwise, here is a CL that would only conditionally create the manual index.


If we succeed at gathering global variables for a compile
unit, there is no need to fallback to generating a manual index.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D106355

Files:
  lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp


Index: lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp
+++ lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp
@@ -125,6 +125,7 @@
 void DebugNamesDWARFIndex::GetGlobalVariables(
     DWARFUnit &cu, llvm::function_ref<bool(DWARFDIE die)> callback) {
   uint64_t cu_offset = cu.GetOffset();
+  bool found_entry_for_cu = false;
   for (const DebugNames::NameIndex &ni: *m_debug_names_up) {
     for (DebugNames::NameTableEntry nte: ni) {
       uint64_t entry_offset = nte.getEntryOffset();
@@ -135,6 +136,7 @@
         if (entry_or->getCUOffset() != cu_offset)
           continue;
 
+        found_entry_for_cu = true;
         if (!ProcessEntry(*entry_or, callback,
                           llvm::StringRef(nte.getString())))
           return;
@@ -142,8 +144,11 @@
       MaybeLogLookupError(entry_or.takeError(), ni, nte.getString());
     }
   }
-
-  m_fallback.GetGlobalVariables(cu, callback);
+  // If no name index for that particular CU was found, fallback to
+  // creating the manual index.
+  if (!found_entry_for_cu) {
+    m_fallback.GetGlobalVariables(cu, callback);
+  }
 }
 
 void DebugNamesDWARFIndex::GetCompleteObjCClass(


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D106355.360084.patch
Type: text/x-patch
Size: 1302 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/lldb-commits/attachments/20210720/398c369b/attachment.bin>