[llvm-strip]Add --no-strip-all to disable --strip-all behaviour (including default stripping)

[jhenderson]

Summary

If certain switches are not specified, llvm-strip behaves as if --strip-all were specified. This means that for testing, when we don't want the stripping behaviour, we have to specify one of these switches, which can be confusing. This change adds --no-strip-all to allow an alternative way of suppressing the default stripping, in a less confusing manner.

[MaskRay]

test/tools/llvm-objcopy/ELF/no-strip-all.test

7

Replace cp %t.o %t1.o with -o %t1.o?

[jhenderson]

test/tools/llvm-objcopy/ELF/no-strip-all.test

7

No, because each of the test cases makes a copy from the pristine version before llvm-strip modifies it.

[MaskRay]

test/tools/llvm-objcopy/ELF/no-strip-all.test

7

llvm-strip %t.o -o %t1.o

[jhenderson]

test/tools/llvm-objcopy/ELF/no-strip-all.test

7

Oh, I see what you mean. Yes, that should work. For some reason, I'd forgotten about -o!

[jakehehrlich]

Good idea! The code looks good as well as testing.

[jhenderson]

Use -o instead of cp.

[MaskRay]

tools/llvm-objcopy/CopyConfig.cpp

722–723

Nit. auto * is more common, but I see the auto Arg below doesn't have the *... so you can ignore me.

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

 # NOTE: This test is only intended to be valid as long as --only-keep-debug is
 #       implemented as a NOP. This test should fail when that changes and you
 #       will need to update this test.
 
 # RUN: yaml2obj %s > %t
 # RUN: llvm-objcopy %t %t2
 # RUN: llvm-objcopy --only-keep-debug %t %t3
 # RUN: cmp %t2 %t3
-# 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 -o %t4
+# RUN: llvm-strip --only-keep-debug --no-strip-all %t -o %t4
 # RUN: cmp %t2 %t4
 
 !ELF
 FileHeader:
   Class:           ELFCLASS64
   Data:            ELFDATA2LSB
   Type:            ET_EXEC
   Machine:         EM_X86_64
 Sections:
   - Name:            .text
     Type:            SHT_PROGBITS
     Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
     Content:         "DEADBEEF"

test/tools/llvm-objcopy/ELF/dynsym-error-remove-strtab.test

 # RUN: not llvm-objcopy -R .dynstr %p/Inputs/dynsym.so %t 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
 # RUN: cp  %p/Inputs/dynsym.so %t2
-## Use --strip-debug to suppress the default --strip-all behavior of llvm-strip.
-## TODO: Implement a better way to suppress --strip-all behavior.
-# RUN: not llvm-strip --strip-debug -R .dynstr %t2 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
+# RUN: not llvm-strip --no-strip-all -R .dynstr %t2 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
 
 # ERR: Section .dynstr cannot be removed because it is referenced by the section .dynsym
 
 # RUN: llvm-objcopy --allow-broken-links -R .dynstr %p/Inputs/dynsym.so %t3
 # RUN: llvm-objdump --section-headers %t3 | FileCheck %s --check-prefix=SECTIONS --implicit-check-not=.dynstr
 # RUN: cp  %p/Inputs/dynsym.so %t4
-# RUN: llvm-strip --strip-debug --allow-broken-links -R .dynstr %t4
+# RUN: llvm-strip --no-strip-all --allow-broken-links -R .dynstr %t4
 # RUN: llvm-objdump --section-headers %t4 | FileCheck %s --check-prefix=SECTIONS --implicit-check-not=.dynstr
 
 # SECTIONS: .dynsym
 # SECTIONS: .dynamic

test/tools/llvm-objcopy/ELF/no-strip-all.test

+## --no-strip-all disables the --strip-all llvm-strip switch.
+## It also disables the default --strip-all behaviour.
+
+# RUN: yaml2obj %s -o %t.o
+
+## Base case: no switches, should strip. Used as a sanity check for later test cases.
+# RUN: cp %t.o %t1.o
+# RUN: llvm-strip %t1.o
+# RUN: llvm-readobj --file-headers --sections %t1.o | FileCheck %s --check-prefix=ALL
+
+## --no-strip-all alone disables stripping.
+# RUN: cp %t.o %t2.o
+# RUN: llvm-strip --no-strip-all %t2.o
+# RUN: llvm-readobj --file-headers --sections %t2.o | FileCheck %s --check-prefix=NO-STRIP
+
+## --no-strip-all wins if last.
+# RUN: cp %t.o %t3.o
+# RUN: llvm-strip --strip-all --no-strip-all %t3.o
+# RUN: cmp %t2.o %t3.o
+
+## --strip-all wins if last.
+# RUN: cp %t.o %t4.o
+# RUN: llvm-strip --no-strip-all --strip-all %t4.o
+# RUN: cmp %t1.o %t4.o
+
+## The last instance of --no-strip-all is used in the comparison.
+# RUN: cp %t.o %t5.o
+# RUN: llvm-strip --no-strip-all --strip-all --no-strip-all %t5.o
+# RUN: cmp %t2.o %t5.o
+
+## The last instance of --strip-all is used in the comparison.
+# RUN: cp %t.o %t6.o
+# RUN: llvm-strip --strip-all --no-strip-all --strip-all %t6.o
+# RUN: cmp %t1.o %t6.o
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_X86_64
+Sections:
+  - Name:  .alloc
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_ALLOC ]
+
+# ALL: SectionHeaderCount: 3
+# ALL: Name: .alloc
+# ALL: Name: .shstrtab
+
+# NO-STRIP: SectionHeaderCount: 5
+# NO-STRIP: Name: .alloc
+# NO-STRIP: Name: .symtab
+# NO-STRIP: Name: .strtab
+# NO-STRIP: Name: .shstrtab

test/tools/llvm-objcopy/ELF/reloc-error-remove-symtab.test

 # RUN: yaml2obj %s > %t
 # RUN: not llvm-objcopy -R .symtab %t %t2 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
 # RUN: cp %t %t3
-## Use --strip-debug to suppress the default --strip-all behavior of llvm-strip.
-## TODO: Implement a better way to suppress --strip-all behavior.
-# RUN: not llvm-strip --strip-debug -R .symtab %t3 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
+# RUN: not llvm-strip --no-strip-all -R .symtab %t3 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
 
 !ELF
 FileHeader:
   Class:           ELFCLASS64
   Data:            ELFDATA2LSB
   Type:            ET_REL
   Machine:         EM_X86_64
 Sections:
- Name:     foo
     Size:     4
     Binding:  STB_GLOBAL
 
 # ERR: Symbol table .symtab cannot be removed because it is referenced by the relocation section .rel.text.
 
 # RUN: llvm-objcopy --allow-broken-links -R .symtab %t %t4
 # RUN: llvm-readobj --sections %t4 | FileCheck %s --check-prefix=SECTIONS --implicit-check-not=.symtab
 # RUN: cp %t %t5
-# RUN: llvm-strip --strip-debug --allow-broken-links -R .symtab %t5
+# RUN: llvm-strip --no-strip-all --allow-broken-links -R .symtab %t5
 # RUN: llvm-readobj --sections %t5 | FileCheck %s --check-prefix=SECTIONS --implicit-check-not=.symtab
 
 # SECTIONS:        Name: .rel.text
 # SECTIONS:        Link
 # SECTIONS-SAME: : 0

test/tools/llvm-objcopy/ELF/remove-linked-section.test

 # RUN: yaml2obj %s -o %t.o
 # RUN: not llvm-objcopy -R .foo %t.o %t1 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
 # RUN: cp %t.o %t2
-## Use --strip-debug to suppress the default --strip-all behavior of llvm-strip.
-## TODO: Implement a better way to suppress --strip-all behavior.
-# RUN: not llvm-strip --strip-debug -R .foo %t2 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
+# RUN: not llvm-strip --no-strip-all -R .foo %t2 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
 
 --- !ELF
 FileHeader:
   Class:           ELFCLASS64
   Data:            ELFDATA2LSB
   Type:            ET_REL
   Machine:         EM_X86_64
 Sections:
   - Name:            .foo
     Type:            SHT_PROGBITS
   - Name:            .bar
     Type:            SHT_PROGBITS
     Link:            .foo
 
 # ERR: Section .foo cannot be removed because it is referenced by the section .bar
 
 # RUN: llvm-objcopy --allow-broken-links -R .foo %t.o %t3
 # RUN: llvm-readobj --sections %t3 | FileCheck %s --check-prefix=SECTIONS --implicit-check-not=.foo
 # RUN: cp %t.o %t4
-# RUN: llvm-strip --strip-debug --allow-broken-links -R .foo %t4
+# RUN: llvm-strip --no-strip-all --allow-broken-links -R .foo %t4
 # RUN: llvm-readobj --sections %t4 | FileCheck %s --check-prefix=SECTIONS --implicit-check-not=.foo
 
 # SECTIONS:      Name: .bar
 # SECTIONS:      Link
 # SECTIONS-SAME: : 0

test/tools/llvm-objcopy/ELF/symtab-error-on-remove-strtab.test

 # RUN: yaml2obj %s > %t
 # RUN: not llvm-objcopy -R .strtab %t %t2 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
 # RUN: cp %t %t3
-## Use --strip-debug to suppress the default --strip-all behavior of llvm-strip.
-## TODO: Implement a better way to suppress --strip-all behavior.
-# RUN: not llvm-strip --strip-debug -R .strtab %t3 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
+# RUN: not llvm-strip --no-strip-all -R .strtab %t3 2>&1 >/dev/null | FileCheck %s --check-prefix=ERR
 
 !ELF
 FileHeader:
   Class:           ELFCLASS64
   Data:            ELFDATA2LSB
   Type:            ET_REL
   Machine:         EM_X86_64
 
 # ERR: String table .strtab cannot be removed because it is referenced by the symbol table .symtab
 
 # RUN: llvm-objcopy --allow-broken-links -R .strtab %t %t4
 # RUN: llvm-objdump --section-headers %t4 | FileCheck %s --check-prefix=SECTIONS --implicit-check-not=.strtab
 # RUN: cp %t %t5
-# RUN: llvm-strip --strip-debug --allow-broken-links -R .strtab %t %t5
+# RUN: llvm-strip --no-strip-all --allow-broken-links -R .strtab %t %t5
 # RUN: llvm-objdump --section-headers %t5 | FileCheck %s --check-prefix=SECTIONS --implicit-check-not=.strtab
 
 # SECTIONS: .symtab

test/tools/llvm-objcopy/ELF/symtab-link.test

 # RUN: yaml2obj %s > %t
 # RUN: llvm-objcopy %t %t2
 # RUN: llvm-readobj --sections %t2 | FileCheck %s
 # RUN: cp %t %t3
-# RUN: llvm-strip --strip-debug %t3
+# RUN: llvm-strip --no-strip-all %t3
 # RUN: llvm-readobj --sections %t3 | FileCheck %s
 
 !ELF
 FileHeader:
   Class:           ELFCLASS64
   Data:            ELFDATA2LSB
   Type:            ET_REL
   Machine:         EM_X86_64

tools/llvm-objcopy/CopyConfig.cpp

Expected<DriverConfig> parseStripOptions(ArrayRef<const char *> ArgsArr) {
   Config.StripDebug = InputArgs.hasArg(STRIP_strip_debug);
 
   if (InputArgs.hasArg(STRIP_discard_all, STRIP_discard_locals))
     Config.DiscardMode =
         InputArgs.hasFlag(STRIP_discard_all, STRIP_discard_locals)
             ? DiscardType::All
             : DiscardType::Locals;
   Config.StripUnneeded = InputArgs.hasArg(STRIP_strip_unneeded);
-  Config.StripAll = InputArgs.hasArg(STRIP_strip_all);
+  if (auto Arg = InputArgs.getLastArg(STRIP_strip_all, STRIP_no_strip_all))
+    Config.StripAll = Arg->getOption().getID() == STRIP_strip_all;
   Config.StripAllGNU = InputArgs.hasArg(STRIP_strip_all_gnu);
   Config.OnlyKeepDebug = InputArgs.hasArg(STRIP_only_keep_debug);
   Config.KeepFileSymbols = InputArgs.hasArg(STRIP_keep_file_symbols);
 
   for (auto Arg : InputArgs.filtered(STRIP_keep_section))
     Config.KeepSection.emplace_back(Arg->getValue(), UseRegexp);
 
   for (auto Arg : InputArgs.filtered(STRIP_remove_section))
     Config.ToRemove.emplace_back(Arg->getValue(), UseRegexp);
 
   for (auto Arg : InputArgs.filtered(STRIP_strip_symbol))
     Config.SymbolsToRemove.emplace_back(Arg->getValue(), UseRegexp);
 
   for (auto Arg : InputArgs.filtered(STRIP_keep_symbol))
     Config.SymbolsToKeep.emplace_back(Arg->getValue(), UseRegexp);
 
-  if (!Config.StripDebug && !Config.StripUnneeded &&
-      Config.DiscardMode == DiscardType::None && !Config.StripAllGNU && Config.SymbolsToRemove.empty())
+  if (!InputArgs.hasArg(STRIP_no_strip_all) && !Config.StripDebug &&
+      !Config.StripUnneeded && Config.DiscardMode == DiscardType::None &&
+      !Config.StripAllGNU && Config.SymbolsToRemove.empty())
     Config.StripAll = true;
 
   Config.DeterministicArchives =
       InputArgs.hasFlag(STRIP_enable_deterministic_archives,
                         STRIP_disable_deterministic_archives, /*default=*/true);
 
   Config.PreserveDates = InputArgs.hasArg(STRIP_preserve_dates);
 

tools/llvm-objcopy/StripOpts.td

 def preserve_dates : Flag<["--"], "preserve-dates">,
                      HelpText<"Preserve access and modification timestamps">;
 def p : Flag<["-"], "p">, Alias<preserve_dates>;
 
 def strip_all : Flag<["--"], "strip-all">,
                 HelpText<"Remove non-allocated sections outside segments. "
                          ".gnu.warning* sections are not removed">;
 def s : Flag<["-"], "s">, Alias<strip_all>;
+def no_strip_all : Flag<["--"], "no-strip-all">,
+                   HelpText<"Disable --strip-all">;
 
 def strip_all_gnu : Flag<["--"], "strip-all-gnu">,
                     HelpText<"Compatible with GNU strip's --strip-all">;
 def strip_debug : Flag<["--"], "strip-debug">,
                   HelpText<"Remove debugging symbols only">;
 def d : Flag<["-"], "d">, Alias<strip_debug>;
 def g : Flag<["-"], "g">, Alias<strip_debug>;
 def S : Flag<["-"], "S">, Alias<strip_debug>;