Fix LLDB build on old Linux kernels

[calebzulawski]

Summary

Usage of aux_size is guarded against elsewhere in this file, but is missing here.

[wallace]

thanks!!

[labath]

I'm pretty sure Caleb does not have commit access. Walter, would you do the honors?

[wallace]

I will! Thanks!

Il Gio 23 Set 2021, 12:35 PM Pavel Labath via Phabricator <
[e-mail]> ha scritto:

labath added a comment.

I'm pretty sure Caleb does not have commit access. Walter, would you do
the honors?

Repository:

rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION

https://reviews.llvm.org/D110269/new/

https://reviews.llvm.org/D110269

lldb/source/Plugins/Process/Linux/IntelPTManager.cpp

while (mask) {
     // clear the lowest bit
     mask &= mask - 1;
   }
   error << ".";
   return createStringError(inconvertibleErrorCode(), error.str().c_str());
 }
 
 size_t IntelPTThreadTrace::GetTraceBufferSize() const {
+#ifndef PERF_ATTR_SIZE_VER5
+  llvm_unreachable("Intel PT Linux perf event not supported");
+#else
   return m_mmap_meta->aux_size;
+#endif
 }
 
 static Expected<uint64_t>
 GeneratePerfEventConfigValue(bool enable_tsc, Optional<size_t> psb_period) {
   uint64_t config = 0;
   // tsc is always supported
   if (enable_tsc) {
     if (Expected<uint32_t> offset = ReadIntelPTConfigFile(