[Lldb-commits] [lldb] [lldb][SymbolFileDWARF] Don't search for DWP files on macOS (PR #139554)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-lldb

Author: Michael Buch (Michael137)

<details>
<summary>Changes</summary>

A contrived performance measurement on my local machine:
1. Attach LLDB to LLDB
2. Measure how much time it takes to run `b operator[]`

Without this patch, we would spend a total of 400ms (which was ~4-5% of total execution) looking for DWP files (and failing to find them because they are not a concept on macOS).

We call into `GetDwpSymbolFile` via `DebugNamesDWARFIndex::GetFunctions -> ManualDWARFIndex::GetFunctions -> ManualDWARFIndex::Index`.

rdar://148212738

---
Full diff: https://github.com/llvm/llvm-project/pull/139554.diff


1 Files Affected:

- (modified) lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp (+3) 


``````````diff
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
index 907d63eb51afe..3f53e562ba65b 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -4211,6 +4211,9 @@ SymbolFileDWARFDebugMap *SymbolFileDWARF::GetDebugMapSymfile() {
 
 const std::shared_ptr<SymbolFileDWARFDwo> &SymbolFileDWARF::GetDwpSymbolFile() {
   llvm::call_once(m_dwp_symfile_once_flag, [this]() {
+    if (m_objfile_sp->GetArchitecture().GetTriple().isAppleMachO())
+      return;
+
     // Create a list of files to try and append .dwp to.
     FileSpecList symfiles;
     // Append the module's object file path.

``````````

</details>


https://github.com/llvm/llvm-project/pull/139554