cargo check,build,rustc --all-targets

[stepancheg]

cargo check does not check all targets by default, and to check
all, you need to call it cargo check --tests --examples --bins --benches. cargo check --all-targets is a shortcut.

--all-targets is added to check, build and to rustc commands.

For consitency --all-targets added to other commands like
test although "all targets" is default behavior.

[rust-highfive]

r? @alexcrichton

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[alexcrichton]

cc #2495, #3431

@matklad do you have thoughts about this feature? I'm sort of ambivalent about it.

[matklad]

For cargo check in particular I think that this should be the default behavior (and if it is the default, we probably don't need a flag). And probably for build and rustc it is also a good default, but I am not sure that changing default is necessary a good idea at this stage.

However, just adding a flag as in this PR seems fine to me as well, because the ability to build everything is very useful for development. (But for IntelliJ in particular, we can default our build command to cargo check --tests --examples --bins --benches once this flags hit stable).

To sum up: adding flag is fine with me (hope that's the last flag in this area), but what about changing the defaults instead?

[malbarbo]

I think --all-targets is misleading because --target has a unrelated meaning.

[stepancheg]

@malbarbo that's good point, however, these things are already called "targets":

    --test NAME                  Check only the specified test target
    --tests                      Check all tests
    --bench NAME                 Check only the specified bench target
    --benches                    Check all benches

Any suggestions of a better name?

[behnam]

This is awesome!

Now that you're on this, maybe it's time to update Check only the specified [...] parts in the descriptions (also for other commands) to be more accurate, as these parameters are union'ed, meaning each options "adds" to the list of targets, not limiting it to "only" that target. (See also #3112 (comment)) IMHO, Check the specified [...] is a shorter, more accurate description here, but maybe we can find something even better.

[alexcrichton]

@matklad I'd actually argue that we don't want this on by default. Especially for build and I'd hazard a guess with check. I personally have never had the desire for "just build everything" but rather I'm always focused on getting something working. I don't mind adding a flag for this, but it doesn't make a lot of sense to me as a default.

I agree with @malbarbo though that the usage of "target" here can be confusing when mixed with cross-compilation flags. The only other thing I can think of, however, is --all-artifacts

[matklad]

I personally have never had the desire for "just build everything" but rather I'm always focused on getting something working.

@alexcrichton sounds reasonable!

Not sure how to deal with ambiguity about targets: it's a fundamental problem in Cargo's terminology, that crate is called target :(

λ cargo build --help | grep target
    --test NAME                  Build only the specified test target
    --bench NAME                 Build only the specified benchmark target
    --target TRIPLE              Build for the target triple

I am not sure that adding artifacts to the mix will be better then sticking with target...

[Xanewok]

Recently I encountered the same problem with how to call those crate 'targets'. I assume using "crate type" isn't good, since it's mostly used for output type like bin, lib, rlib etc.? Maybe something along the lines of "crate build type" or "crate target" to disambiguate?

[alexcrichton]

I personally think we should stick with --all-targets if we do this. It's unfortuante, yes, but there seem to be few other suggestions.

[stepancheg]

Another option is to rename it to --all-build-targets. And change comment of --target to "Build for the platform target triple".

[alexcrichton]

That also seems plausible to me, I'm fine either way

[bors]

☔ The latest upstream changes (presumably #4248) made this pull request unmergeable. Please resolve the merge conflicts.

[behnam]

Another option is to rename it to --all-build-targets. And change comment of --target to "Build for the platform target triple".

My two cents: in most other compiler/build-systems "build target" almost always means the target platform. Here, it's more of a "target package" or "target crate".

[matklad]

@behnam yeah, I think what Cargo calls a "target" is usually known as an "artifact". But we probably can't replace existing Cargo terminology, especially for this single issue, which just exemplifies the general problem.

👍 to sticking with --all-targets. If we ever need all target triples, we could use --all-target-triples

[behnam]

Yeah, --all-targets can definitely work.

At some point, I was thinking that --all could be a synonym for --all-packages, and what's being added here could also be --all-package-crates, --all-package-targets, or even --all-crates, for short, since from the compiler's perspective, these are called crates, and from Cargo perspective, targets.

[alexcrichton]

@stepancheg would you be willing to rebase this to land?

[alexcrichton]

Closing in favor of #4400