[llvm-objcopy][MachO] Implement --strip-debug

[MaskRay]

Summary

alexshap, jhenderson, seiya

[alexander-shaposhnikov]

LG

[smeenai]

llvm/test/tools/llvm-objcopy/MachO/strip-debug.test

1

This isn't actually calling llvm-strip, as far as I can see? Is the llvm-strip driver supported for Mach-O?

[MaskRay]

llvm/test/tools/llvm-objcopy/MachO/strip-debug.test

1

https://reviews.llvm.org/D70476

[jhenderson]

llvm/test/tools/llvm-objcopy/MachO/strip-debug.test

1

For future reference, I believe the above link should be https://reviews.llvm.org/D70995

llvm/test/tools/llvm-objcopy/MachO/strip-debug.test

+## Show that llvm-objcopy/llvm-strip removes all symbols and debug sections.
+
+# RUN: yaml2obj %p/Inputs/strip-all-with-dwarf.yaml -o %t
+
+# RUN: llvm-objcopy --strip-debug %t %t.stripped
+# RUN: llvm-readobj --sections %t.stripped | FileCheck /dev/null --check-prefix=NODWARF \
+# RUN:   --implicit-check-not='Name: __debug' --implicit-check-not='Name: __apple'
+
+## Make sure that all symbols are kept.
+# RUN: llvm-readobj --symbols %t | FileCheck %s --check-prefix=SYM
+# RUN: llvm-readobj --symbols %t.stripped | FileCheck %s --check-prefix=SYM
+
+# SYM:         Symbols [
+# SYM-COUNT-3: Symbol
+# SYM:         ]
+
+## Make sure that all relocations to non-debug sections are kept.
+# RUN: llvm-readobj -r %t | FileCheck %s --check-prefixes=RELOC,DEBUG
+# RUN: llvm-readobj -r %t.stripped | FileCheck %s --check-prefix=RELOC
+
+# RELOC:      Relocations [
+# RELOC-NEXT:   Section __text {
+# RELOC-NEXT:     0x0 0 0 0 X86_64_RELOC_UNSIGNED 0 -
+# RELOC-NEXT:     0x0 0 0 0 X86_64_RELOC_UNSIGNED 0 -
+# RELOC-NEXT:   }
+# DEBUG:        Section __debug_info {
+# DEBUG-NEXT:     0x0 0 0 0 X86_64_RELOC_UNSIGNED 0 -
+# DEBUG-NEXT:     0x0 0 0 0 X86_64_RELOC_UNSIGNED 0 -
+# DEBUG-NEXT:     0x0 0 0 0 X86_64_RELOC_UNSIGNED 0 -
+# DEBUG-NEXT:     0x0 0 0 0 X86_64_RELOC_UNSIGNED 0 -
+# DEBUG-NEXT:   }
+# RELOC-NEXT:   Section __compact_unwind {
+# RELOC-NEXT:     0x0 0 0 0 X86_64_RELOC_UNSIGNED 0 -
+# RELOC-NEXT:   }
+# DEBUG-NEXT:   Section __debug_line {
+# DEBUG-NEXT:     0x0 0 0 0 X86_64_RELOC_UNSIGNED 0 -
+# DEBUG-NEXT:   }
+# RELOC-NEXT: ]

llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp

static void removeSections(const CopyConfig &Config, Object &Obj) {
   SectionPred RemovePred = [](const Section &) { return false; };
 
   if (!Config.ToRemove.empty()) {
     RemovePred = [&Config, RemovePred](const Section &Sec) {
       return Config.ToRemove.matches(Sec.CanonicalName);
     };
   }
 
-  if (Config.StripAll) {
+  if (Config.StripAll || Config.StripDebug) {
     // Remove all debug sections.
     RemovePred = [RemovePred](const Section &Sec) {
       if (Sec.Segname == "__DWARF")
         return true;
 
       return RemovePred(Sec);
     };
   }
if (Config.AllowBrokenLinks || !Config.BuildIdLinkDir.empty() ||
       !Config.SymbolsToKeep.empty() || !Config.SymbolsToLocalize.empty() ||
       !Config.SymbolsToWeaken.empty() || !Config.SymbolsToKeepGlobal.empty() ||
       !Config.SectionsToRename.empty() ||
       !Config.UnneededSymbolsToRemove.empty() ||
       !Config.SetSectionAlignment.empty() || !Config.SetSectionFlags.empty() ||
       Config.ExtractDWO || Config.KeepFileSymbols || Config.LocalizeHidden ||
       Config.PreserveDates || Config.StripAllGNU || Config.StripDWO ||
       Config.StripNonAlloc || Config.StripSections || Config.Weaken ||
-      Config.DecompressDebugSections || Config.StripDebug ||
-      Config.StripNonAlloc || Config.StripSections || Config.StripUnneeded ||
+      Config.DecompressDebugSections || Config.StripNonAlloc ||
+      Config.StripSections || Config.StripUnneeded ||
       Config.DiscardMode != DiscardType::None || !Config.SymbolsToAdd.empty() ||
       Config.EntryExpr) {
     return createStringError(llvm::errc::invalid_argument,
                              "option not supported by llvm-objcopy for MachO");
   }
   removeSections(Config, Obj);
 
   // Mark symbols to determine which symbols are still needed.