reword #[test] attribute error on fn items

[zeegomo]

fix of #55787
Reworded error message from "#[test] attribute is only allowed on fn items" to "#[test] attribute is only allowed on non associated functions"

[rust-highfive]

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[estebank]

Can you add a test? Other than that, r=me.

[zeegomo]

sure, where should I add it? I can't find other tests of that file

[estebank]

Create a file in src/test/ui/ with a repro case and run ./x.py test src/test/ui --stage 1 --bless to create the .stderr. Add both files to git and push the change.

[rust-highfive]

The job x86_64-gnu-llvm-5.0 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

travis_time:end:08c1702f:start=1542451322851476102,finish=1542451380828192047,duration=57976715945
$ git checkout -qf FETCH_HEAD
travis_fold:end:git.checkout

Encrypted environment variables have been removed for security reasons.
See https://docs.travis-ci.com/user/pull-requests/#Pull-Requests-and-Security-Restrictions
$ export SCCACHE_BUCKET=rust-lang-ci-sccache2
$ export SCCACHE_REGION=us-west-1
Setting environment variables from .travis.yml
$ export IMAGE=x86_64-gnu-llvm-5.0
---

[00:03:48] travis_fold:start:tidy
travis_time:start:tidy
tidy check
[00:03:48] tidy error: /checkout/src/test/ui/test-attr-non-associated-functions.rs:2: trailing whitespace
[00:03:48] tidy error: /checkout/src/test/ui/test-attr-non-associated-functions.rs:8: tab character
[00:03:48] tidy error: /checkout/src/test/ui/test-attr-non-associated-functions.rs:8: trailing whitespace
[00:03:48] tidy error: /checkout/src/test/ui/test-attr-non-associated-functions.rs:9: tab character
[00:03:48] tidy error: /checkout/src/test/ui/test-attr-non-associated-functions.rs:9: trailing whitespace
[00:03:48] tidy error: /checkout/src/test/ui/test-attr-non-associated-functions.rs:10: tab character
[00:03:48] tidy error: /checkout/src/test/ui/test-attr-non-associated-functions.rs:11: tab character
[00:03:48] tidy error: /checkout/src/test/ui/test-attr-non-associated-functions.rs:16: tab character
[00:03:48] tidy error: /checkout/src/test/ui/test-attr-non-associated-functions.rs: missing trailing newline
[00:03:50] some tidy checks failed
[00:03:50] 
[00:03:50] 
[00:03:50] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/tidy" "/checkout/src" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "--no-vendor" "--quiet"
[00:03:50] 
[00:03:50] 
[00:03:50] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test src/tools/tidy
[00:03:50] Build completed unsuccessfully in 0:00:50
[00:03:50] Build completed unsuccessfully in 0:00:50
[00:03:50] make: *** [tidy] Error 1
[00:03:50] Makefile:79: recipe for target 'tidy' failed
The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:00a6e390
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
Sat Nov 17 10:47:02 UTC 2018
---
travis_time:end:10b814fa:start=1542451622936716297,finish=1542451622946324094,duration=9607797
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:0a7aad23
$ ln -s . checkout && for CORE in obj/cores/core.*; do EXE=$(echo $CORE | sed 's|obj/cores/core\.[0-9]*\.!checkout!\(.*\)|\1|;y|!|/|'); if [ -f "$EXE" ]; then printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" "$CORE"; gdb --batch -q -c "$CORE" "$EXE" -iex 'set auto-load off' -iex 'dir src/' -iex 'set sysroot .' -ex bt -ex q; echo travis_fold":"end:crashlog; fi; done || true
travis_fold:end:after_failure.4
travis_fold:start:after_failure.5
travis_time:start:12810648
travis_time:start:12810648
$ cat ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers || true
cat: ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers: No such file or directory
travis_fold:end:after_failure.5
travis_fold:start:after_failure.6
travis_time:start:04fd6dd8
$ dmesg | grep -i kill

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[pietroalbini]

@bors r=estebank rollup

[bors]

📌 Commit 8e13e43 has been approved by estebank

[Centril]

I would rephrase non associated functions as free functions to avoid the negative.

[zeegomo]

a simple search of "rust free functions" on duckduckgo or "free functions" on the rust book has no results while "associated functions" gives you the expected page, that's why I chose that phrase.

[Centril]

Sadly the page in the book is quite wrong in that it defines "associated function" as a non-method inside an implementation (trait/inherent). Thus, by saying "non-associated function", by the incorrect definition in the book you are stating that #[test] is allowed on methods. Given this, I think if you want to impart a correct error you need to say something like:

"#[test] attribute is only allowed on free functions without arguments"

or:

"#[test] attribute is only allowed on no-argument functions outside implementations"