[llvm-objcopy] Make llvm-strip --only-keep-debug suppress default --strip-all

[jmciver]

Summary

The following commit resolves Issue #54417. Fixes llvm-strip conditional command
line option logic to not enable --strip-all in the presence of
--only-keep-debug.

[jmciver]

Patch is ready for review.

I am not sure if there would be value in adding a test with --only-keep-debug and --strip-all. Let me know if you think this would be useful and I can add it.

Thanks in advance for your feedback.

[MaskRay]

[llvm-objcopy] llvm-strip option --only-keep-debug should suppress default --strip-all

An imperative sentence is more common as the subject line.
option in option --only-keep-debug does not convey extra information.
You may use [llvm-objcopy] Make llvm-strip --only-keep-debug suppress default --strip-all

llvm/test/tools/llvm-objcopy/ELF/only-keep-debug.test

8

Add a comment ## --only-keep-debug suppresses the default --strip-all.

[jmciver]

Updating D123798: [llvm-objcopy] llvm-strip option --only-keep-debug should suppress default --strip-all

Add comment to ELF/only-keep-debug.test explaining default option override. This
change is per feedback provided during the patch review process.

[jmciver]

[llvm-objcopy] llvm-strip option --only-keep-debug should suppress default --strip-all

The following commit resolves Issue #54417. Fixes llvm-strip conditional command
line option logic to not enable --strip-all in the presence of
--only-keep-debug.

[jmciver]

[llvm-objcopy] llvm-strip option --only-keep-debug should suppress default --strip-all

The following commit resolves Issue #54417. Fixes llvm-strip conditional command
line option logic to not enable --strip-all in the presence of
--only-keep-debug.

[jmciver]

@MaskRay Thank you for your feedback! I have implemented the following changes:

• Comment has been added to ELF/only-keep-debug.test explaining that --only-keep-debug overrides --strip-all
• Differential title has been updated to be more imperative

Sorry about the extra revision diffs (still learning arc), squashing commits worked.

Once this is re-approved can someone please commit on my behalf:
Name: John McIver
Email: [e-mail]

Thanks again @MaskRay for taking the time to review!

llvm/test/tools/llvm-objcopy/COFF/only-keep-debug.test

 RUN: yaml2obj %p/Inputs/only-keep-sections.yaml -o %t.in.exe
 
 RUN: llvm-objcopy --only-keep-debug %t.in.exe %t.out.exe
 RUN: llvm-readobj --sections %t.out.exe | FileCheck %s --check-prefix=SECTIONS
 RUN: llvm-objdump -t %t.out.exe | FileCheck %s --check-prefix=SYMBOLS
-# Run llvm-strip with --strip-symbol on a non-existent symbol to prevent
-# defaulting to --strip-all.
-RUN: llvm-strip --only-keep-debug --strip-symbol foo %t.in.exe -o %t-strip.out.exe
+
+## --only-keep-debug suppresses the default --strip-all.
+RUN: llvm-strip --only-keep-debug %t.in.exe -o %t-strip.out.exe
 RUN: cmp %t.out.exe %t-strip.out.exe
 
 Check that all non-debug/buildid sections with IMAGE_SCN_CNT_CODE
 or IMAGE_SCN_CNT_INITIALIZED_DATA are truncated, and no others.
 
 SECTIONS:      Sections [
 SECTIONS-NEXT:  Section {
 SECTIONS-NEXT:   Number: 1

llvm/test/tools/llvm-objcopy/ELF/only-keep-debug.test

 # RUN: yaml2obj --docnum=1 %s -o %t1
 # RUN: llvm-objcopy --only-keep-debug %t1 %t1.dbg
 # RUN: llvm-readelf -S -l -x .note1 -x .note2 -x .debug_abbrev -x .debug_frame -x .debug_info %t1.dbg | FileCheck %s
+## --only-keep-debug suppresses the default --strip-all.
+# RUN: llvm-strip --only-keep-debug %t1
+# RUN: llvm-readelf -S -l -x .note1 -x .note2 -x .debug_abbrev -x .debug_frame -x .debug_info %t1 | FileCheck %s
 
 ## Check that SHT_NOTE and .debug* are kept, but others are changed to SHT_NOBITS.
 ## SHT_NOBITS sections do not occupy space in the output.
 
 # CHECK:      [Nr] Name          Type     Address          Off    Size   ES Flg Lk Inf Al
 # CHECK:      [ 1] .note1        NOTE     0000000000000400 000400 000001 00   A  0   0 1024
 # CHECK-NEXT: [ 2] .note2        NOTE     0000000000000401 000401 000001 00   A  0   0  0
 # CHECK-NEXT: [ 3] .text         NOBITS   0000000000000402 000402 000001 00  AX  0   0  0
 # CHECK-NEXT: [ 4] .tdata        NOBITS   0000000000001480 000480 000007 00 WAT  0   0 128
 # CHECK-NEXT: [ 5] .tbss         NOBITS   0000000000001487 000480 000005 00 WAT  0   0  0

llvm/tools/llvm-objcopy/ObjcopyOptions.cpp

if (Error E = Config.SymbolsToRemove.addMatcher(NameOrPattern::create(
       return std::move(E);
 
   for (auto Arg : InputArgs.filtered(STRIP_keep_symbol))
     if (Error E = Config.SymbolsToKeep.addMatcher(NameOrPattern::create(
             Arg->getValue(), SymbolMatchStyle, ErrorCallback)))
       return std::move(E);
 
   if (!InputArgs.hasArg(STRIP_no_strip_all) && !Config.StripDebug &&
-      !Config.StripUnneeded && Config.DiscardMode == DiscardType::None &&
-      !Config.StripAllGNU && Config.SymbolsToRemove.empty())
+      !Config.OnlyKeepDebug && !Config.StripUnneeded &&
+      Config.DiscardMode == DiscardType::None && !Config.StripAllGNU &&
+      Config.SymbolsToRemove.empty())
     Config.StripAll = true;
 
   if (Config.DiscardMode == DiscardType::All) {
     Config.StripDebug = true;
     ELFConfig.KeepFileSymbols = true;
   }
 
   Config.DeterministicArchives =