./configure --help should print --disable-docs instead of --enable-docs

[dilyanpalauzov]

With rust 1.80 ./configure --help prints:

        --enable-docs                  build standard library documentation 

This means, that by default the standard librarly documentation is not built, but with this option it can be turned on.

However, config.example.toml contains

# Whether to build documentation by default. If false, rustdoc and
# friends will still be compiled but they will not be used to generate any
# documentation.
#
# You can still build documentation when this is disabled by explicitly passing paths,
# e.g. `x doc library`.
#docs = true

For me the last line means, that by default the documentation is build. Indeed, ./configure --disable-docs puts in config.toml: docs = false.

• Change the output of ./configure --help from --enable-docs to --disable-docs to indicate what actions users should take in order to deviate from the default.

[saksham-agarwal-dev]

@rustbot claim

[saksham-agarwal-dev]

print('') print('This configure script is a thin configuration shim over the true') print('configuration system,config.toml. You can explore the comments') print('in config.example.tomlnext to this configure script to see') print('more information about what each option is. Additionally you can') print('pass--setas an argument to set arbitrary key/value pairs') print('in the TOML configuration if desired') print('') print('Also note that all options which take--enablecan similarly') print('be passed with--disable-footo forcibly disable the option')

Right after printing the --enable-docs, there is also this disclaimer.

I am a first-time contributor to Rust.
Should I add some conditional logic for checking what the default value for that option is and printing --enable-{} or --disable-{} based on that default?

Thanks for the guidance.

[arin-r]

Should I add some conditional logic for checking what the default value for that option is and printing --enable-{} or --disable-{} based on that default?

I believe default option for building docs is true, that is, documentation is built by default.

[saksham-agarwal-dev]

Hi, I got that.
My question was whether should I add some conditional logic to check if the default value for any given option is true or false.
Right now, the script doesn't care if something is enabled or disabled by default, it only prints --enable-{option}.

I am thinking we need to somehow get the default values for each option and print --enable or --disable accordingly.

[saksham-agarwal-dev]

#130125

[onur-ozkan]

Change the output of ./configure --help from --enable-docs to --disable-docs to indicate what actions users should take in order to deviate from the default.

This will still be a problem in the future. I'm sure there are other unsynced flags in configure --help. We should probably change how we write the helper docs. Instead of printing enable-$option, we should make it clearer that users can control options with enable and disable.

[dilyanpalauzov]

Instead of printing enable-$option, we should make it clearer that users can control options with enable and disable.

--help should indicate what is the default and how to change it. Currently it does not say what the default is.

[onur-ozkan]

--help should indicate what is the default and how to change it.

What makes you think that?

[dilyanpalauzov]

All --help output of autoconf, etc. should work in similar way. As the output is short, for each option there should be indication what the default is (static, auto=or depends on parameters discovered while running the configure-script). And it should indicate how to change the default. Obviously there is no point to pass parameters, which trigger anyway the default behaviour and the output of --help should suggest only how to deviate from the defaults, not how to keep the defaults.

[onur-ozkan]

configure is nothing like autoconf. It's just a wrapper for this python script and most default (as some of them defined in config profiles) values are managed by the rust side bootstrap. We can't display default values in the configure script because it's a different program and it's not possible until we remove the python programs and handle everything from single program (which is our plan). Until then, I think this should be useful enough.

[saksham-agarwal-dev]

@rustbot release-assignment

[AvatarSenju]

@rustbot claim

[AvatarSenju]

raised PR #131117 taking @onur-ozkan suggestion of updating the helper docs till python wrapper is deprecated.

[jieyouxu]

Fixed by #131117.

[dilyanpalauzov]

The problem report here is, that --help does not indicate, if a feature is by default on or off. In turn it does not show how to deviate from the default (and suppress information how to enforce the default).

#131117 is not a fix to the problem addressed here. If you are not willing to show on --help what the defaults are, if no parameters are passed, is a different story.

I wrote an article on whether to print --enable-M or --disable-M on --help : https://ab.bapha.be/posts/help-output/.

[onur-ozkan]

This is not a valid issue anymore, please open another one if you think --help behaviour should be different.