How to silence unused command line argument error with clang without disabling it?

Question

When using -Werror with clang, it transforms "warning: argument unused during compilation" messages into errors, which makes sense. There's a -Qunused-arguments flag to silence them entirely. My question is, is there some -Wno-error=... flag I can pass to make these not be errors, without disabling them entirely?

`unused-arguments` is about unused command line flags, not arguments in code. — Alex Gaynor, Feb 07 '14 at 00:44
Please show the whole command line and the whole message produced by clang. — Jens, Feb 07 '14 at 13:43
Is the code your own? If so, then I would advice you to prevent the warning in the source code itself. See: http://stackoverflow.com/questions/3599160/unused-parameter-warnings-in-c-code — Ruud Helderman, Feb 07 '14 at 15:03

score 36 · Accepted Answer · answered Feb 07 '14 at 14:56

36

Turns out the correct answer is -Wno-error=unused-command-line-argument.

answered Feb 07 '14 at 14:56

Alex Gaynor

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This seems necessary when runnning Clang with `-stdlib=libc++` through `distcc`. – rubenvb Jan 01 '17 at 22:04
Seems to have changed clang9 now uses -Qunused-arguments. – wheredidthatnamecomefrom Nov 22 '19 at 21:42

score 12 · Answer 2 · answered Feb 01 '18 at 16:52

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You can also use this command:

-Wno-unused-command-line-argument

answered Feb 01 '18 at 16:52

Enye Aaron Shi

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score 1 · Answer 3 · answered Aug 27 '19 at 05:49

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In my case, I had similar issues with autoconf while using clang-8 compiler in ./configure.

*clang-8: error: unknown argument: '-ftree-loop-distribute-patterns'*
*clang-8: error: unknown argument: '-fno-semantic-interposition'*

I needed following command line to fix these errors:

./configure CC=clang-8 CXX=clang++-8 LD=clang++-8 CFLAGS=-Qunused-arguments

Hope this is helpful to others.

answered Aug 27 '19 at 05:49

naveenKumar

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Thanks for showing an example. This, however, does not work for `clang++` (I know the question tagged `c`. Just wanted to make it clear for anyone trying it for C++). https://godbolt.org/z/GqodhYWv7 – User 10482 May 27 '23 at 17:32

score 0 · Answer 4 · answered Feb 07 '14 at 10:59

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#pragma clang diagnostic ignored "-Wunused-parameter"

answered Feb 07 '14 at 10:59

BLUEPIXY

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score 0 · Answer 5 · answered Sep 12 '19 at 14:39

In Visual Studio 2019, open the property pages of the C++ Project and go to Configuration Properties -> C/C++ -> CommandLine.

In the "Additional Options" text box, paste

-Wunused-command-line-argument

Do this for each configuration / platform combination. This worked for me, to turn off only this warning.

score 0 · Answer 6 · answered Apr 11 '23 at 22:33

Use --start-no-unused-arguments and --end-no-unused-arguments to silence the warning only for some arguments.

This is convenient for flags like -stdlib (warns if used with C code), -rtlib and -unwindlib (warn if used during compilation as opposed to linking).

How to silence unused command line argument error with clang without disabling it?

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