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Remove or use variables which are unused but set.
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Authored by mbenfield on May 21 2021, 1:20 PM.

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Summary

This is in preparation for the -Wunused-but-set-variable warning.

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Event Timeline

mbenfield created this revision.May 21 2021, 1:20 PM
mbenfield requested review of this revision.May 21 2021, 1:20 PM
Herald added projects: Restricted Project, Restricted Project. · View Herald TranscriptMay 21 2021, 1:20 PM

Several variables I have just removed outright, including

llvm/lib/Target/X86/X86FloatingPoint.cpp: STDeadDefs
lldb/source/Plugins/ABI/PowerPC/ABISysV_ppc.cpp: fp_bytes
lldb/source/Interpreter/CommandInterpreter.cpp: actual_cmd_name_len

Someone familiar with this code should probably look at these and determine whether these variables not being used could have lead to buggy behavior.

dblaikie accepted this revision.May 21 2021, 2:56 PM
dblaikie added a subscriber: dblaikie.

Sure, all sounds good - if you can, please reach out to the authors of any of the semantics changing changes (the ones related to the Changed values in transformations) to see if they could add missing test coverage.

llvm/lib/Target/AArch64/GISel/AArch64PostSelectOptimize.cpp
183

Might want to CC/respond to whoever wrote this to see if someone missed test coverage for this code.

llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
1227–1230

Maybe in a separate patch would be good to switch this around to:

if (!LoLoop.Preheader)
  return Changed;
LoLoop.Start = SearchForStart(LoLoop.Preheader);
1230

Also might be worth reaching out to authors to check that this change is intended & possibly tested.

This revision is now accepted and ready to land.May 21 2021, 2:56 PM
teemperor accepted this revision.Mon, May 24, 2:04 AM
teemperor added a subscriber: teemperor.

ABISysV_ppc.cpp feels a bit like this should be used to calculate some offset, but I don't think that's for this review to figure out what is wrong there. The other LLDB changes LGTM.

lldb/source/Interpreter/CommandInterpreter.cpp
3104

Was already checked in unused and I don't see what we would need that for, LGTM.

lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp
342

This code was apparently rendered obsolete by 89870cebcb0c9996f49336a21e72b80511f37341 so LGTM

Sure, all sounds good - if you can, please reach out to the authors of any of the semantics changing changes (the ones related to the Changed values in transformations) to see if they could add missing test coverage.

Sure, I emailed Sam Parker and Amara Emerson.

lebedev.ri resigned from this revision.Sun, May 30, 2:32 PM

(removing from my queue - i don't expect to provide any review here)

samparker added inline comments.
llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
1230

Ah, yes this should be fine. The Changed value would only be used by the pipeline manager and this pass is the last transform in the Arm pipeline.

I also heard via email from Amara Emerson that the change is fine for similar reasons.

I also heard via email from Amara Emerson that the change is fine for similar reasons.

Great, thanks for checking!