llvm-objcopy: Add support for -g as an alias for --strip-debug

[dyung]

Summary

This change adds an option -g to llvm-objcopy which is an alias for the existing option --strip-debug.

I also modified the existing tests which use the --strip-debug option to exercise the -g option as well.

This fixes PR40003.

[alexander-shaposhnikov]

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

4 ↗

(On Diff #183474)

what is this second run for ? appears to be exactly the same as the line 2

[dyung]

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

4 ↗

(On Diff #183474)

Whoops, I don't know why I added those, it was unnecessary. I'll remove them. Thanks for catching that.

[dyung]

Removed extra test lines that were not needed.

[alexander-shaposhnikov]

test/tools/llvm-objcopy/COFF/only-section.test

13 ↗

(On Diff #183475)

i don't have a strong opinion regarding this, but generally when the output is expected to be exactly the same i wouldn't do text matching twice (it all contributes to the time it takes to run all the tests), i'd simply run cmp %t.combination.exe %t.combination_g.exe - it's much cheaper.

p.s. maybe there are other similar places, pls, have a look.

[rupprecht]

Code lgtm, just have nits on the testing. Thanks!

test/tools/llvm-objcopy/ELF/help-message.test

14 ↗

(On Diff #183475)

Not related to this patch really, but --strip-debug isn't needed for this test case -- the same error message should be printed with just llvm-strip (no args)

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

10 ↗

(On Diff #183475)

This test -- running cmp against -g and --strip-debug output -- is really all that's needed. Duplication in all the other tests is not providing any more coverage. I think it's safe to revert all the other test files and all other modifications in this file.

[dyung]

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

10 ↗

(On Diff #183475)

I agree. I'll remove the rest of the changes and update the diff.

[alexander-shaposhnikov]

I agree with Jordan regarding tests, otherwise this change looks good to me.

[dyung]

Remove redundant testing and leave in one check that -g and --strip-debug produce identical output.

llvm/trunk/test/tools/llvm-objcopy/ELF/strip-debug.test

 # RUN: yaml2obj %s > %t
 # RUN: cp %t %t3
 # RUN: llvm-objcopy --strip-debug %t %t2
 # RUN: llvm-readobj --file-headers --sections --symbols %t2 | FileCheck %s
 
 # Verify that the previous run of llvm-objcopy has not modified the input.
 # RUN: cmp %t %t3
 
+# RUN: llvm-objcopy -g %t %t2g
+# Verify that --strip-debug and -g produce the same output
+# RUN: cmp %t2 %t2g
+
 # RUN: llvm-strip --strip-debug %t3
 # RUN: cmp %t2 %t3
 
 # RUN: cp %t %t4
 # RUN: llvm-strip -d %t4
 # RUN: cmp %t2 %t4
 
 # RUN: cp %t %t5

llvm/trunk/tools/llvm-objcopy/ObjcopyOpts.td

def strip_all
     : Flag<["-", "--"], "strip-all">,
       HelpText<
           "Remove non-allocated sections other than .gnu.warning* sections">;
 def S : Flag<["-"], "S">, Alias<strip_all>;
 def strip_all_gnu : Flag<["-", "--"], "strip-all-gnu">,
                     HelpText<"Compatible with GNU objcopy's --strip-all">;
 def strip_debug : Flag<["-", "--"], "strip-debug">,
                   HelpText<"Remove all debug information">;
+def g : Flag<["-"], "g">, Alias<strip_debug>,
+        HelpText<"Alias for --strip-debug">;
 def strip_dwo : Flag<["-", "--"], "strip-dwo">,
                 HelpText<"Remove all DWARF .dwo sections from file">;
 def strip_sections : Flag<["-", "--"], "strip-sections">,
                      HelpText<"Remove all section headers">;
 def strip_non_alloc : Flag<["-", "--"], "strip-non-alloc">,
                       HelpText<"Remove all non-allocated sections">;
 def strip_unneeded : Flag<["-", "--"], "strip-unneeded">,
                      HelpText<"Remove all symbols not needed by relocations">;