[llvm-objcopy] Add support for '--' for delimiting options from input/output files

[sdmitriev]

Summary

This will allow to use llvm-objcopy with file names that begin with dashes.

[jhenderson]

I'm not against the functional change, but why have so many tests changed? You should have a single dedicated test that covers this, rather than arbitrarily modifying existing tests to cover the new behaviour. As this is not file format specific, it can even be put in the top-level llvm-objcopy directory, although you may want a comment saying it is testing generic behaviour, since it'll presumably need to use e.g. an ELF object to avoid the "no input file" error.

Is there a particular reason you've singled out llvm-objcopy, and not llvm-strip?

llvm/tools/llvm-objcopy/CopyConfig.cpp

478

Nit: fix this clang-tidy issue.

486

What about the case where a user does llvm-objcopy -- with no arguments or input files? What does GNU objcopy do in this case?

[sdmitriev]

I agree that it would be better to create a single LIT test for a file name beginning with dash, but it is not clear how to write it. I assume such test would require use of %T (directory of a %t), but according to the documentation it is deprecated now. So, I decided to follow the same strategy for testing this patch as was used in a similar llvm-rc change (D56743) - updating few arbitrary tests to use ‘--’ separator for the file names. If you have ideas how to write a test for a file name beginning with ‘-‘, please share.

Is there a particular reason you've singled out llvm-objcopy, and not llvm-strip?

No, no particular reason. I only needed this to be supported in llvm-objcopy, so I’ve changed this tool only. But I can prepare a similar change for llvm-strip as well in a separate patch.

llvm/tools/llvm-objcopy/CopyConfig.cpp

486

GNU objcopy prints help in this case. I have updated this change to match GNU objcopy behavior:

llvm-objcopy -- => print help
llvm-objcopy -- <file> => empty output

[jhenderson]

In D102665#2765456, @sdmitriev wrote:

I agree that it would be better to create a single LIT test for a file name beginning with dash, but it is not clear how to write it. I assume such test would require use of %T (directory of a %t), but according to the documentation it is deprecated now. So, I decided to follow the same strategy for testing this patch as was used in a similar llvm-rc change (D56743) - updating few arbitrary tests to use ‘--’ separator for the file names. If you have ideas how to write a test for a file name beginning with ‘-‘, please share.

You can use something like mkdir %t in tests (see various cases throughout the testsuites) and then cd into that directory, where you can then use relative names, e.g. to files starting with -, without neeing %t to be involved.

Is there a particular reason you've singled out llvm-objcopy, and not llvm-strip?

No, no particular reason. I only needed this to be supported in llvm-objcopy, so I’ve changed this tool only. But I can prepare a similar change for llvm-strip as well in a separate patch.

Sounds reasonable.

llvm/tools/llvm-objcopy/CopyConfig.cpp

478

Actually, auto doesn't really gain us anything here, as the return type is not obvious from the single line here. Just make the type explicit.

[sdmitriev]

Addressed review comments.

[jhenderson]

llvm/test/tools/llvm-objcopy/objcopy-dash-dash.test

1 ↗

(On Diff #346106)

Nit: in newer llvm-objcopy tests, we tend to use ## for comment markers, to make the comments stand out clearly from the test directives.

Also, no need for "objcopy" to be in the name. dash-dash.test would be sufficient. Since the functionality for llvm-strip would be nearly identical, it could live in the same test.

4–5 ↗

(On Diff #346106)

I would change the commnet slightly to make it generic - after all, non-dashed files are still valid after this point too. Something like:

"Check that llvm-objcopy correctly treats paths after "--" as file paths, even if they start with dashes."

You would then have a case where the name has a dash as a leading character, and another where it doesn't. I'd make the filenames with a leading dash valid options too.

Also, I recommend you test the following cases:

1. -- is specified with options but no input files.
2. -- is specified with input files but no options.

8 ↗

(On Diff #346106)

You don't need to check the full file properties. In fact, I'd recommend doing a run without -- and then use cmp to compare this with the output of the different test cases.

10–19 ↗

(On Diff #346106)

This can be dramatically simplified. We don't need a section at all, and I believe the Machine is optional too. You can also remove excess padding, and add the --- to properly start the YAML.

[sdmitriev]

Addressed review comments.

[jhenderson]

LGTM, with one suggestion.

llvm/test/tools/llvm-objcopy/dash-dash.test

12 ↗

(On Diff #346147)

I'd put the -- before test-obj here. That way, you have coverage for all positional arguments being after the --. It also removes the potential for positional arguments either side of the -- treating the first as an option (in terms of whether the lack of options is an issue).

[sdmitriev]

Applied code review suggestions.

[hubert.reinterpretcast]

llvm/test/tools/llvm-objcopy/dash-dash.test

9 ↗

(On Diff #346364)

This is causing a bot failure:
https://lab.llvm.org/staging/#/builders/126/builds/421/steps/5/logs/FAIL__LLVM__dash-dash_test

If you have some cmp that requires the --, I have found that using env POSIXLY_CORRECT=1 cmp would help.

[hubert.reinterpretcast]

llvm/test/tools/llvm-objcopy/dash-dash.test

9 ↗

(On Diff #346364)

Or using cmp -- out-obj1 --only-section would work.

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

 # RUN: yaml2obj %s -o %t
 
 ## Test that llvm-objcopy adds a section to the given object with expected
 ## contents.
 # RUN: echo DEADBEEF > %t.sec
-# RUN: llvm-objcopy --add-section=.test.section=%t.sec %t %t1
+# RUN: llvm-objcopy --add-section=.test.section=%t.sec -- %t %t1
 # RUN: llvm-readobj --file-headers --sections --section-data %t1 | FileCheck %s --check-prefixes=CHECK-ADD
 
 # CHECK-ADD:      SectionCount: 2
 # CHECK-ADD:      Name: .text
 # CHECK-ADD:      Name: .test.section
 # CHECK-ADD:      Characteristics [
 # CHECK-ADD-NEXT:   IMAGE_SCN_ALIGN_1BYTES
 # CHECK-ADD-NEXT:   IMAGE_SCN_CNT_INITIALIZED_DATA
 # CHECK-ADD-NEXT: ]
 # CHECK-ADD:      SectionData (
 # CHECK-ADD-NEXT:  0000: {{.+}}|DEADBEEF{{.+}}|
 # CHECK-ADD-NEXT: )
 
 ## Test that llvm-objcopy can add a section with an empty name.
-# RUN: llvm-objcopy --add-section==%t.sec %t %t1.empty.name
+# RUN: llvm-objcopy --add-section==%t.sec -- %t %t1.empty.name
 # RUN: llvm-readobj --file-headers --sections --section-data %t1.empty.name | FileCheck %s --check-prefixes=CHECK-ADD-EMPTY-NAME
 
 # CHECK-ADD-EMPTY-NAME:      SectionCount: 2
 # CHECK-ADD-EMPTY-NAME:      Name: .text
 # CHECK-ADD-EMPTY-NAME:      Name: (00 00 00 00 00 00 00 00)
 # CHECK-ADD-EMPTY-NAME:      Characteristics [
 # CHECK-ADD-EMPTY-NAME-NEXT:   IMAGE_SCN_ALIGN_1BYTES
 # CHECK-ADD-EMPTY-NAME-NEXT:   IMAGE_SCN_CNT_INITIALIZED_DATA
 # CHECK-ADD-EMPTY-NAME-NEXT: ]
 # CHECK-ADD-EMPTY-NAME:      SectionData (
 # CHECK-ADD-EMPTY-NAME-NEXT:  0000: {{.+}}|DEADBEEF{{.+}}|
 # CHECK-ADD-EMPTY-NAME-NEXT: )
 
 ## Test that llvm-objcopy can add a section to an object with extended
 ## relocations.
 # RUN: %python %p/../Inputs/ungzip.py %p/Inputs/x86_64-obj-xrelocs.yaml.gz > %t.xrelocs.yaml
 # RUN: yaml2obj %t.xrelocs.yaml -o %t.xrelocs.obj
-# RUN: llvm-objcopy --add-section=.test.section=%t.sec %t.xrelocs.obj %t1.xrelocs.obj
+# RUN: llvm-objcopy --add-section=.test.section=%t.sec -- %t.xrelocs.obj %t1.xrelocs.obj
 # RUN: llvm-readobj --file-headers --sections --section-data %t1.xrelocs.obj | FileCheck %s --check-prefixes=CHECK-EXTENDED-RELOCS
 
 # CHECK-EXTENDED-RELOCS:      SectionCount: 2
 # CHECK-EXTENDED-RELOCS:      Name: .data
 # CHECK-EXTENDED-RELOCS:      RelocationCount: 65535
 # CHECK-EXTENDED-RELOCS:      Characteristics [
 # CHECK-EXTENDED-RELOCS-NEXT:   IMAGE_SCN_ALIGN_16BYTES
 # CHECK-EXTENDED-RELOCS-NEXT:   IMAGE_SCN_CNT_INITIALIZED_DATA
 # CHECK-EXTENDED-RELOCS-NEXT:   IMAGE_SCN_LNK_NRELOC_OVFL
 # CHECK-EXTENDED-RELOCS-NEXT:   IMAGE_SCN_MEM_READ
 # CHECK-EXTENDED-RELOCS-NEXT: ]
 # CHECK-EXTENDED-RELOCS:      Name: .test.section
 # CHECK-EXTENDED-RELOCS:      Characteristics [
 # CHECK-EXTENDED-RELOCS-NEXT:   IMAGE_SCN_ALIGN_1BYTES
 # CHECK-EXTENDED-RELOCS-NEXT:   IMAGE_SCN_CNT_INITIALIZED_DATA
 # CHECK-EXTENDED-RELOCS-NEXT: ]
 # CHECK-EXTENDED-RELOCS:      SectionData (
 # CHECK-EXTENDED-RELOCS-NEXT:  0000: {{.+}}|DEADBEEF{{.+}}|
 # CHECK-EXTENDED-RELOCS-NEXT: )
 
 ## Test that llvm-objcopy produces an error if the file with section contents
 ## to be added does not exist.
-# RUN: not llvm-objcopy --add-section=.another.section=%t2 %t %t3 2>&1 | FileCheck -DFILE1=%t -DFILE2=%t2 -DMSG=%errc_ENOENT %s --check-prefixes=ERR1
+# RUN: not llvm-objcopy --add-section=.another.section=%t2 -- %t %t3 2>&1 | FileCheck -DFILE1=%t -DFILE2=%t2 -DMSG=%errc_ENOENT %s --check-prefixes=ERR1
 
 # ERR1: error: '[[FILE1]]': '[[FILE2]]': [[MSG]]
 
 ## Another negative test for invalid --add-sections command line argument.
-# RUN: not llvm-objcopy --add-section=.another.section %t %t3 2>&1 | FileCheck %s --check-prefixes=ERR2
+# RUN: not llvm-objcopy --add-section=.another.section -- %t %t3 2>&1 | FileCheck %s --check-prefixes=ERR2
 
 # ERR2: error: bad format for --add-section: missing '='
 
 ## Negative test for invalid --add-sections argument - missing file name.
-# RUN: not llvm-objcopy --add-section=.section.name= %t %t3 2>&1 | FileCheck %s --check-prefixes=ERR3
+# RUN: not llvm-objcopy --add-section=.section.name= -- %t %t3 2>&1 | FileCheck %s --check-prefixes=ERR3
 
 # ERR3: error: bad format for --add-section: missing file name
 
 --- !COFF
 header:
   Machine:         IMAGE_FILE_MACHINE_AMD64
   Characteristics: [  ]
 sections:
   - Name:            .text
     Characteristics: [  ]
     Alignment:       4
     SectionData:     488B0500000000C3
 symbols:
 ...

llvm/test/tools/llvm-objcopy/COFF/set-section-flags.test

 # RUN: yaml2obj %s -o %t
 
 ## Single flag on a section with no flags:
-# RUN: llvm-objcopy --set-section-flags=.foo=alloc %t %t.alloc
+# RUN: llvm-objcopy --set-section-flags=.foo=alloc -- %t %t.alloc
 # RUN: llvm-readobj --sections %t.alloc | FileCheck %s --check-prefixes=CHECK,UNINITDATA,READ,WRITE
-# RUN: llvm-objcopy --set-section-flags=.foo=load %t %t.load
+# RUN: llvm-objcopy --set-section-flags=.foo=load -- %t %t.load
 # RUN: llvm-readobj --sections %t.load | FileCheck %s --check-prefixes=CHECK,READ,WRITE
-# RUN: llvm-objcopy --set-section-flags=.foo=noload %t %t.noload
+# RUN: llvm-objcopy --set-section-flags=.foo=noload -- %t %t.noload
 # RUN: llvm-readobj --sections %t.noload | FileCheck %s --check-prefixes=CHECK,READ,WRITE,REMOVE
-# RUN: llvm-objcopy --set-section-flags=.foo=readonly %t %t.readonly
+# RUN: llvm-objcopy --set-section-flags=.foo=readonly -- %t %t.readonly
 # RUN: llvm-readobj --sections %t.readonly | FileCheck %s --check-prefixes=CHECK,READ
-# RUN: llvm-objcopy --set-section-flags=.foo=exclude %t %t.exclude
+# RUN: llvm-objcopy --set-section-flags=.foo=exclude -- %t %t.exclude
 # RUN: llvm-readobj --sections %t.exclude | FileCheck %s --check-prefixes=CHECK,READ,WRITE,REMOVE
-# RUN: llvm-objcopy --set-section-flags=.foo=debug %t %t.debug
+# RUN: llvm-objcopy --set-section-flags=.foo=debug -- %t %t.debug
 # RUN: llvm-readobj --sections %t.debug | FileCheck %s --check-prefixes=CHECK,INITDATA,DISCARDABLE,READ,WRITE
-# RUN: llvm-objcopy --set-section-flags=.foo=code %t %t.code
+# RUN: llvm-objcopy --set-section-flags=.foo=code -- %t %t.code
 # RUN: llvm-readobj --sections %t.code | FileCheck %s --check-prefixes=CHECK,CODE,EXECUTE,READ,WRITE
-# RUN: llvm-objcopy --set-section-flags=.foo=data %t %t.data
+# RUN: llvm-objcopy --set-section-flags=.foo=data -- %t %t.data
 # RUN: llvm-readobj --sections %t.data | FileCheck %s --check-prefixes=CHECK,INITDATA,READ,WRITE
-# RUN: llvm-objcopy --set-section-flags=.foo=rom %t %t.rom
+# RUN: llvm-objcopy --set-section-flags=.foo=rom -- %t %t.rom
 # RUN: llvm-readobj --sections %t.rom | FileCheck %s --check-prefixes=CHECK,READ,WRITE
-# RUN: llvm-objcopy --set-section-flags=.foo=contents %t %t.contents
+# RUN: llvm-objcopy --set-section-flags=.foo=contents -- %t %t.contents
 # RUN: llvm-readobj --sections %t.contents | FileCheck %s --check-prefixes=CHECK,READ,WRITE
-# RUN: llvm-objcopy --set-section-flags=.foo=merge %t %t.merge
+# RUN: llvm-objcopy --set-section-flags=.foo=merge -- %t %t.merge
 # RUN: llvm-readobj --sections %t.merge | FileCheck %s --check-prefixes=CHECK,READ,WRITE
-# RUN: llvm-objcopy --set-section-flags=.foo=strings %t %t.strings
+# RUN: llvm-objcopy --set-section-flags=.foo=strings -- %t %t.strings
 # RUN: llvm-readobj --sections %t.strings | FileCheck %s --check-prefixes=CHECK,READ,WRITE
-# RUN: llvm-objcopy --set-section-flags=.foo=share %t %t.share
+# RUN: llvm-objcopy --set-section-flags=.foo=share -- %t %t.share
 # RUN: llvm-readobj --sections %t.share | FileCheck %s --check-prefixes=CHECK,READ,SHARED,WRITE
 
 ## Multiple flags:
-# RUN: llvm-objcopy --set-section-flags=.foo=alloc,readonly,share %t %t.alloc_ro_share
+# RUN: llvm-objcopy --set-section-flags=.foo=alloc,readonly,share -- %t %t.alloc_ro_share
 # RUN: llvm-readobj --sections %t.alloc_ro_share | FileCheck %s --check-prefixes=CHECK,UNINITDATA,READ,SHARED
-# RUN: llvm-objcopy --set-section-flags=.foo=alloc,code %t %t.alloc_code
+# RUN: llvm-objcopy --set-section-flags=.foo=alloc,code -- %t %t.alloc_code
 # RUN: llvm-readobj --sections %t.alloc_code | FileCheck %s --check-prefixes=CHECK,CODE,UNINITDATA,EXECUTE,READ,WRITE
 
 ## Invalid flags:
-# RUN: not llvm-objcopy --set-section-flags=.foo=xyzzy %t %t.xyzzy 2>&1 | FileCheck %s --check-prefix=BAD-FLAG
+# RUN: not llvm-objcopy --set-section-flags=.foo=xyzzy -- %t %t.xyzzy 2>&1 | FileCheck %s --check-prefix=BAD-FLAG
 
 ## Bad flag format:
-# RUN: not llvm-objcopy --set-section-flags=.foo %t %t2 2>&1 | FileCheck %s --check-prefix=BAD-FORMAT
+# RUN: not llvm-objcopy --set-section-flags=.foo -- %t %t2 2>&1 | FileCheck %s --check-prefix=BAD-FORMAT
 
 ## Setting flags for the same section multiple times:
-# RUN: not llvm-objcopy --set-section-flags=.foo=alloc --set-section-flags=.foo=load %t %t2 2>&1 | FileCheck %s --check-prefix=MULTIPLE-SETS
+# RUN: not llvm-objcopy --set-section-flags=.foo=alloc --set-section-flags=.foo=load -- %t %t2 2>&1 | FileCheck %s --check-prefix=MULTIPLE-SETS
 
 ## Upper-case flags:
-# RUN: llvm-objcopy --set-section-flags=.foo=ALLOC,LOAD,NOLOAD,READONLY,DEBUG,CODE,DATA,ROM,CONTENTS,MERGE,STRINGS,SHARE %t %t.upper
+# RUN: llvm-objcopy --set-section-flags=.foo=ALLOC,LOAD,NOLOAD,READONLY,DEBUG,CODE,DATA,ROM,CONTENTS,MERGE,STRINGS,SHARE -- %t %t.upper
 # RUN: llvm-readobj --sections %t.upper | FileCheck %s --check-prefixes=CHECK,CODE,INITDATA,REMOVE,DISCARDABLE,EXECUTE,READ,SHARED
 
 ## Mixed-case flags:
-# RUN: llvm-objcopy --set-section-flags=.foo=aLlOc,LoAd,NoLoad,rEAdONly,Debug,codE,DaTa,rOm,CoNtEnTs,mErGe,sTRINGs,SharE %t %t.mixed
+# RUN: llvm-objcopy --set-section-flags=.foo=aLlOc,LoAd,NoLoad,rEAdONly,Debug,codE,DaTa,rOm,CoNtEnTs,mErGe,sTRINGs,SharE -- %t %t.mixed
 # RUN: llvm-readobj --sections %t.mixed | FileCheck %s --check-prefixes=CHECK,CODE,INITDATA,REMOVE,DISCARDABLE,EXECUTE,READ,SHARED
 
 --- !COFF
 header:
   Machine:         IMAGE_FILE_MACHINE_AMD64
   Characteristics: [ ]
 sections:
   - Name:            .foo

llvm/test/tools/llvm-objcopy/ELF/add-section.test

 # RUN: yaml2obj %s -o %t
-# RUN: llvm-objcopy -O binary -j .test2 %t %t.sec
-# RUN: llvm-objcopy -R .test2 %t %t2
-# RUN: llvm-objcopy --add-section=.test2=%t.sec %t2 %t3
+# RUN: llvm-objcopy -O binary -j .test2 -- %t %t.sec
+# RUN: llvm-objcopy -R .test2 -- %t %t2
+# RUN: llvm-objcopy --add-section=.test2=%t.sec -- %t2 %t3
 # RUN: llvm-readobj --file-headers --sections --section-data %t3 | FileCheck %s
 
 !ELF
 FileHeader:
   Class:           ELFCLASS64
   Data:            ELFDATA2LSB
   Type:            ET_REL
   Machine:         EM_X86_64

 # CHECK-NEXT: AddressAlignment: 1
 # CHECK-NEXT: EntrySize: 0
 # CHECK-NEXT: SectionData (
 # CHECK-NEXT:   0000: DEADBEEF
 # CHECK-NEXT: )
 
 ## Test that llvm-objcopy produces an error if the file with section contents
 ## to be added does not exist.
-# RUN: not llvm-objcopy --add-section=.section.name=%t.missing %t %t.out 2>&1 | FileCheck -DFILE1=%t -DFILE2=%t.missing -DMSG=%errc_ENOENT %s --check-prefixes=ERR1
+# RUN: not llvm-objcopy --add-section=.section.name=%t.missing -- %t %t.out 2>&1 | FileCheck -DFILE1=%t -DFILE2=%t.missing -DMSG=%errc_ENOENT %s --check-prefixes=ERR1
 
 # ERR1: error: '[[FILE1]]': '[[FILE2]]': [[MSG]]
 
 ## Negative test for invalid --add-sections argument - missing '='.
-# RUN: not llvm-objcopy --add-section=.section.name %t %t.out 2>&1 | FileCheck %s --check-prefixes=ERR2
+# RUN: not llvm-objcopy --add-section=.section.name -- %t %t.out 2>&1 | FileCheck %s --check-prefixes=ERR2
 
 # ERR2: error: bad format for --add-section: missing '='
 
 ## Negative test for invalid --add-sections argument - missing file name.
-# RUN: not llvm-objcopy --add-section=.section.name= %t %t.out 2>&1 | FileCheck %s --check-prefixes=ERR3
+# RUN: not llvm-objcopy --add-section=.section.name= -- %t %t.out 2>&1 | FileCheck %s --check-prefixes=ERR3
 
 # ERR3: error: bad format for --add-section: missing file name

llvm/test/tools/llvm-objcopy/ELF/set-section-flags.test

 # RUN: yaml2obj %s -o %t
 
 # Single flags on a section with no flags:
 # RUN: llvm-objcopy --set-section-flags=.foo=alloc \
-# RUN:   --set-section-flags=.baz=alloc --set-section-flags=.rela.baz=alloc %t %t.alloc
+# RUN:   --set-section-flags=.baz=alloc --set-section-flags=.rela.baz=alloc -- %t %t.alloc
 # RUN: llvm-readobj --sections %t.alloc | FileCheck %s --check-prefixes=CHECK,NOBITS,ALLOC,WRITE
 # RUN: llvm-objcopy --set-section-flags=.foo=load \
-# RUN:   --set-section-flags=.baz=load --set-section-flags=.rela.baz=load %t %t.load
+# RUN:   --set-section-flags=.baz=load --set-section-flags=.rela.baz=load -- %t %t.load
 # RUN: llvm-readobj --sections %t.load | FileCheck %s --check-prefixes=CHECK,PROGBITS,WRITE
 # RUN: llvm-objcopy --set-section-flags=.foo=noload \
-# RUN:   --set-section-flags=.baz=noload --set-section-flags=.rela.baz=noload %t %t.noload
+# RUN:   --set-section-flags=.baz=noload --set-section-flags=.rela.baz=noload -- %t %t.noload
 # RUN: llvm-readobj --sections %t.noload | FileCheck %s --check-prefixes=CHECK,PROGBITS,WRITE
 # RUN: llvm-objcopy --set-section-flags=.foo=readonly \
-# RUN:   --set-section-flags=.baz=readonly --set-section-flags=.rela.baz=readonly %t %t.readonly
+# RUN:   --set-section-flags=.baz=readonly --set-section-flags=.rela.baz=readonly -- %t %t.readonly
 # RUN: llvm-readobj --sections %t.readonly | FileCheck %s --check-prefixes=CHECK,PROGBITS
 # RUN: llvm-objcopy --set-section-flags=.foo=exclude \
-# RUN:   --set-section-flags=.baz=exclude --set-section-flags=.rela.baz=exclude %t %t.exclude
+# RUN:   --set-section-flags=.baz=exclude --set-section-flags=.rela.baz=exclude -- %t %t.exclude
 # RUN: llvm-readobj --sections %t.exclude | FileCheck %s --check-prefixes=CHECK,PROGBITS,EXCLUDE,WRITE
 # RUN: llvm-objcopy --set-section-flags=.foo=debug \
-# RUN:   --set-section-flags=.baz=debug --set-section-flags=.rela.baz=debug %t %t.debug
+# RUN:   --set-section-flags=.baz=debug --set-section-flags=.rela.baz=debug -- %t %t.debug
 # RUN: llvm-readobj --sections %t.debug | FileCheck %s --check-prefixes=CHECK,PROGBITS,WRITE
 # RUN: llvm-objcopy --set-section-flags=.foo=code \
-# RUN:   --set-section-flags=.baz=code --set-section-flags=.rela.baz=code %t %t.code
+# RUN:   --set-section-flags=.baz=code --set-section-flags=.rela.baz=code -- %t %t.code
 # RUN: llvm-readobj --sections %t.code | FileCheck %s --check-prefixes=CHECK,PROGBITS,EXEC,WRITE
 # RUN: llvm-objcopy --set-section-flags=.foo=data \
-# RUN:   --set-section-flags=.baz=data --set-section-flags=.rela.baz=data %t %t.data
+# RUN:   --set-section-flags=.baz=data --set-section-flags=.rela.baz=data -- %t %t.data
 # RUN: llvm-readobj --sections %t.data | FileCheck %s --check-prefixes=CHECK,PROGBITS,WRITE
 # RUN: llvm-objcopy --set-section-flags=.foo=rom \
-# RUN:   --set-section-flags=.baz=rom --set-section-flags=.rela.baz=rom %t %t.rom
+# RUN:   --set-section-flags=.baz=rom --set-section-flags=.rela.baz=rom -- %t %t.rom
 # RUN: llvm-readobj --sections %t.rom | FileCheck %s --check-prefixes=CHECK,PROGBITS,WRITE
 # RUN: llvm-objcopy --set-section-flags=.foo=contents \
-# RUN:   --set-section-flags=.baz=contents --set-section-flags=.rela.baz=contents %t %t.contents
+# RUN:   --set-section-flags=.baz=contents --set-section-flags=.rela.baz=contents -- %t %t.contents
 # RUN: llvm-readobj --sections %t.contents | FileCheck %s --check-prefixes=CHECK,PROGBITS,WRITE
 # RUN: llvm-objcopy --set-section-flags=.foo=merge \
-# RUN:   --set-section-flags=.baz=merge --set-section-flags=.rela.baz=merge %t %t.merge
+# RUN:   --set-section-flags=.baz=merge --set-section-flags=.rela.baz=merge -- %t %t.merge
 # RUN: llvm-readobj --sections %t.merge | FileCheck %s --check-prefixes=CHECK,MERGE,PROGBITS,WRITE
 # RUN: llvm-objcopy --set-section-flags=.foo=strings \
-# RUN:   --set-section-flags=.baz=strings --set-section-flags=.rela.baz=strings %t %t.strings
+# RUN:   --set-section-flags=.baz=strings --set-section-flags=.rela.baz=strings -- %t %t.strings
 # RUN: llvm-readobj --sections %t.strings | FileCheck %s --check-prefixes=CHECK,STRINGS,PROGBITS,WRITE
 # RUN: llvm-objcopy --set-section-flags=.foo=share \
-# RUN:   --set-section-flags=.baz=share --set-section-flags=.rela.baz=share %t %t.share
+# RUN:   --set-section-flags=.baz=share --set-section-flags=.rela.baz=share -- %t %t.share
 # RUN: llvm-readobj --sections %t.share | FileCheck %s --check-prefixes=CHECK,PROGBITS,WRITE
 
 # Multiple flags:
 # RUN: llvm-objcopy --set-section-flags=.foo=alloc,readonly,strings \
 # RUN:   --set-section-flags=.baz=alloc,readonly,strings \
-# RUN:   --set-section-flags=.rela.baz=alloc,readonly,strings %t %t.alloc_ro_strings
+# RUN:   --set-section-flags=.rela.baz=alloc,readonly,strings -- %t %t.alloc_ro_strings
 # RUN: llvm-readobj --sections %t.alloc_ro_strings | FileCheck %s --check-prefixes=CHECK,NOBITS,ALLOC,STRINGS
 # RUN: llvm-objcopy --set-section-flags=.foo=alloc,code \
 # RUN:   --set-section-flags=.baz=alloc,code \
-# RUN:   --set-section-flags=.rela.baz=alloc,code %t %t.alloc_code
+# RUN:   --set-section-flags=.rela.baz=alloc,code -- %t %t.alloc_code
 # RUN: llvm-readobj --sections %t.alloc_code | FileCheck %s --check-prefixes=CHECK,NOBITS,ALLOC,EXEC,WRITE
 
 # Invalid flags:
-# RUN: not llvm-objcopy --set-section-flags=.foo=xyzzy %t %t.xyzzy 2>&1 | FileCheck %s --check-prefix=BAD-FLAG
+# RUN: not llvm-objcopy --set-section-flags=.foo=xyzzy -- %t %t.xyzzy 2>&1 | FileCheck %s --check-prefix=BAD-FLAG
 
 # Bad flag format:
-# RUN: not llvm-objcopy --set-section-flags=.foo %t %t2 2>&1 | FileCheck %s --check-prefix=BAD-FORMAT
+# RUN: not llvm-objcopy --set-section-flags=.foo -- %t %t2 2>&1 | FileCheck %s --check-prefix=BAD-FORMAT
 
 # Setting flags for the same section multiple times:
-# RUN: not llvm-objcopy --set-section-flags=.foo=alloc --set-section-flags=.foo=load %t %t2 2>&1 | FileCheck %s --check-prefix=MULTIPLE-SETS
+# RUN: not llvm-objcopy --set-section-flags=.foo=alloc --set-section-flags=.foo=load -- %t %t2 2>&1 | FileCheck %s --check-prefix=MULTIPLE-SETS
 
 # Upper-case flags:
 # RUN: llvm-objcopy --set-section-flags=.foo=ALLOC,LOAD,NOLOAD,READONLY,DEBUG,CODE,DATA,ROM,CONTENTS,MERGE,STRINGS,SHARE \
 # RUN:   --set-section-flags=.baz=ALLOC,LOAD,NOLOAD,READONLY,DEBUG,CODE,DATA,ROM,CONTENTS,MERGE,STRINGS,SHARE \
-# RUN:   --set-section-flags=.rela.baz=ALLOC,LOAD,NOLOAD,READONLY,DEBUG,CODE,DATA,ROM,CONTENTS,MERGE,STRINGS,SHARE %t %t.upper
+# RUN:   --set-section-flags=.rela.baz=ALLOC,LOAD,NOLOAD,READONLY,DEBUG,CODE,DATA,ROM,CONTENTS,MERGE,STRINGS,SHARE -- %t %t.upper
 # RUN: llvm-readobj --sections %t.upper | FileCheck %s --check-prefixes=CHECK,PROGBITS,ALLOC,EXEC,MERGE,STRINGS
 
 # Mixed-case flags:
 # RUN: llvm-objcopy --set-section-flags=.foo=aLlOc,LoAd,NoLoad,rEAdONly,Debug,codE,DaTa,rOm,CoNtEnTs,mErGe,sTRINGs,SharE \
 # RUN:   --set-section-flags=.baz=aLlOc,LoAd,NoLoad,rEAdONly,Debug,codE,DaTa,rOm,CoNtEnTs,mErGe,sTRINGs,SharE \
-# RUN:   --set-section-flags=.rela.baz=aLlOc,LoAd,NoLoad,rEAdONly,Debug,codE,DaTa,rOm,CoNtEnTs,mErGe,sTRINGs,SharE %t %t.mixed
+# RUN:   --set-section-flags=.rela.baz=aLlOc,LoAd,NoLoad,rEAdONly,Debug,codE,DaTa,rOm,CoNtEnTs,mErGe,sTRINGs,SharE -- %t %t.mixed
 # RUN: llvm-readobj --sections %t.mixed | FileCheck %s --check-prefixes=CHECK,PROGBITS,ALLOC,EXEC,MERGE,STRINGS
 
 ## Unspecified sections are not affected:
-# RUN: llvm-objcopy --set-section-flags=.foo=alloc %t %t.unspecified
+# RUN: llvm-objcopy --set-section-flags=.foo=alloc -- %t %t.unspecified
 # RUN: llvm-readobj --sections %t.unspecified | FileCheck %s --check-prefixes=UNSPECIFIED
 
 !ELF
 FileHeader:
   Class:           ELFCLASS64
   Data:            ELFDATA2LSB
   Type:            ET_REL
   Machine:         EM_X86_64

llvm/test/tools/llvm-objcopy/MachO/add-section-32.test

 ## Show that llvm-objcopy adds a new section into a 32-bit object file if
 ## --add-section is given.
 
 # RUN: yaml2obj %s -o %t
 # RUN: echo -n abcdefg > %t.data
 
 ## Case 1: Add a new section into an existing segment.
-# RUN: llvm-objcopy --add-section __TEXT,__bar=%t.data %t %t.out1
+# RUN: llvm-objcopy --add-section __TEXT,__bar=%t.data -- %t %t.out1
 # RUN: llvm-readobj --sections --section-data %t.out1 \
 # RUN:   | FileCheck %s --check-prefixes=COMMON,CASE1
 
 ## Case 2: Add a new section into a nonexistent segment.
-# RUN: llvm-objcopy --add-section __FOO,__bar=%t.data %t %t.out2
+# RUN: llvm-objcopy --add-section __FOO,__bar=%t.data -- %t %t.out2
 # RUN: llvm-readobj --sections --section-data %t.out2 \
 # RUN:   | FileCheck %s --check-prefixes=COMMON,CASE2
 
 ## Case 3: Add a new section into an existing segment using /dev/null as an input.
-# RUN: llvm-objcopy --add-section __TEXT,__bar=/dev/null %t %t.out3
+# RUN: llvm-objcopy --add-section __TEXT,__bar=/dev/null -- %t %t.out3
 # RUN: llvm-readobj --sections --section-data %t.out3 \
 # RUN:   | FileCheck %s --check-prefixes=COMMON,CASE3
 
 --- !mach-o
 FileHeader:
   magic:           0xFEEDFACE
   cputype:         0x00000007
   cpusubtype:      0x00000003

llvm/test/tools/llvm-objcopy/MachO/add-section-64.test

 ## Show that llvm-objcopy adds a new section into a 64-bit object if
 ## --add-section is given.
 
 # RUN: yaml2obj %s -o %t
 # RUN: echo -n abcdefg > %t.data
 
 ## Case 1: Add a new section into an existing segment.
-# RUN: llvm-objcopy --add-section __TEXT,__bar=%t.data %t %t.out1
+# RUN: llvm-objcopy --add-section __TEXT,__bar=%t.data -- %t %t.out1
 # RUN: llvm-readobj --sections --section-data %t.out1 \
 # RUN:   | FileCheck %s --check-prefixes=COMMON,CASE1
 
 ## Case 2: Add a new section into a nonexistent segment.
-# RUN: llvm-objcopy --add-section __FOO,__bar=%t.data %t %t.out2
+# RUN: llvm-objcopy --add-section __FOO,__bar=%t.data -- %t %t.out2
 # RUN: llvm-readobj --sections --section-data %t.out2 \
 # RUN:   | FileCheck %s --check-prefixes=COMMON,CASE2
 # RUN: llvm-readobj --sections --section-data %t.out2 \
 # RUN:   | FileCheck %s --check-prefixes=COMMON,CASE2
 
 ## Case 3: Add a new section into an existing segment using /dev/null as an input.
-# RUN: llvm-objcopy --add-section __TEXT,__bar=/dev/null %t %t.out3
+# RUN: llvm-objcopy --add-section __TEXT,__bar=/dev/null -- %t %t.out3
 # RUN: llvm-readobj --sections --section-data %t.out3 \
 # RUN:   | FileCheck %s --check-prefixes=COMMON,CASE3
 
 --- !mach-o
 FileHeader:
   magic:           0xFEEDFACF
   cputype:         0x01000007
   cpusubtype:      0x00000003

llvm/test/tools/llvm-objcopy/wasm/add-section.test

 ## Test --add-section. This test dumps and removes the section first and checks
 ## that adding it back doesn't change the result.
 # RUN: yaml2obj %s -o %t
-# RUN: llvm-objcopy --dump-section=producers=%t.sec --remove-section=producers %t %t2
-# RUN: llvm-objcopy --add-section=producers=%t.sec %t2 %t3
+# RUN: llvm-objcopy --dump-section=producers=%t.sec --remove-section=producers -- %t %t2
+# RUN: llvm-objcopy --add-section=producers=%t.sec -- %t2 %t3
 # RUN: obj2yaml %t3 | FileCheck %s
 
 ## Check that the producers section has been added back unchanged.
 # CHECK:      Name: producers
 # CHECK-NEXT: Tools:
 # CHECK-NEXT:  - Name:    clang
 # CHECK-NEXT:    Version: 9.0.0
 
 # Check that the section is replaced with new content in one invocation.
 # RUN: echo "123" > %t4
-# RUN: llvm-objcopy --remove-section=foo --add-section=foo=%t4 %t %t5
+# RUN: llvm-objcopy --remove-section=foo --add-section=foo=%t4 -- %t %t5
 # RUN: obj2yaml %t5 | FileCheck %s --check-prefix=REPLACE
 
 # REPLACE: - Type:  CUSTOM
 # REPLACE:   Name:    foo
 # REPLACE:   Payload: 3132330A
 
 --- !WASM
 FileHeader:

llvm/tools/llvm-objcopy/CopyConfig.cpp

static void printHelp(const opt::OptTable &OptTable, raw_ostream &OS,
   // but libOption does not have that yet.
   OS << "\nPass @FILE as argument to read options from FILE.\n";
 }
 
 // ParseObjcopyOptions returns the config and sets the input arguments. If a
 // help flag is set then ParseObjcopyOptions will print the help messege and
 // exit.
 Expected<DriverConfig>
-parseObjcopyOptions(ArrayRef<const char *> ArgsArr,
+parseObjcopyOptions(ArrayRef<const char *> RawArgsArr,
                     llvm::function_ref<Error(Error)> ErrorCallback) {
   DriverConfig DC;
   ObjcopyOptTable T;
+
+  auto DashDash = std::find_if(RawArgsArr.begin(), RawArgsArr.end(),
+                               [](StringRef Str) { return Str == "--"; });
+  ArrayRef<const char *> ArgsArr = makeArrayRef(RawArgsArr.begin(), DashDash);
+
   unsigned MissingArgumentIndex, MissingArgumentCount;
   llvm::opt::InputArgList InputArgs =
       T.ParseArgs(ArgsArr, MissingArgumentIndex, MissingArgumentCount);
 
-  if (InputArgs.size() == 0) {
+  if (InputArgs.size() == 0 && DashDash == RawArgsArr.end()) {
     printHelp(T, errs(), ToolType::Objcopy);
     exit(1);
   }
 
   if (InputArgs.hasArg(OBJCOPY_help)) {
     printHelp(T, outs(), ToolType::Objcopy);
     exit(0);
   }
 
   if (InputArgs.hasArg(OBJCOPY_version)) {
     outs() << "llvm-objcopy, compatible with GNU objcopy\n";
     cl::PrintVersionMessage();
     exit(0);
   }
 
   SmallVector<const char *, 2> Positional;
 
   for (auto Arg : InputArgs.filtered(OBJCOPY_UNKNOWN))
     return createStringError(errc::invalid_argument, "unknown argument '%s'",
                              Arg->getAsString(InputArgs).c_str());
 
   for (auto Arg : InputArgs.filtered(OBJCOPY_INPUT))
     Positional.push_back(Arg->getValue());
+  if (DashDash != RawArgsArr.end())
+    std::copy(std::next(DashDash), RawArgsArr.end(),
+              std::back_inserter(Positional));
 
   if (Positional.empty())
     return createStringError(errc::invalid_argument, "no input file specified");
 
   if (Positional.size() > 2)
     return createStringError(errc::invalid_argument,
                              "too many positional arguments");