Implement dbg_macro rule #3723

rhysd · 2019-01-30T17:48:22Z

This patch adds new dbg_macro rule to check dbg! macro use.

Since this is my first patch to clippy, I'm not confident about following points:

~~Currently only checks dbg! span. Is it possible to check if the dbg! macro is provided by standard library or user-defined? If it's possible, I can make the check more strict.~~ Resolved as Implement dbg_macro rule #3723 (comment)
~~Is category style correct for this rule?~~'restriction' is used instead
~~Should I use span_lint_and_sugg instead of span_lint? Currently entire message is put as msg. But later part ensure to avoid having uses of it in version control may be put as suggestion.~~ Done
I'm not native English speaker. The message and doc may not be natural as English.

mati865 · 2019-01-30T19:39:17Z

If somebody is using Clippy during development (through RLS for an example) this warning will appear all the time.
@oli-obk is there any way to detect debug or release build from within Clippy?

oli-obk

is there any way to detect debug or release build from within Clippy?

That's a little problematic, the compiler itself only has a notion of optimization levels and debug info, not release/debug. The latter is solely a cargo concept. What we can do is ask which cfgs have been set by looking at cx.tcx.sess.parse_sess.config. Maybe there are cfgs for release/debug?

oli-obk · 2019-01-30T20:05:08Z

clippy_lints/src/dbg_macro.rs

+/// ```
+declare_clippy_lint! {
+    pub DBG_MACRO,
+    style,


I wonder if we need a whole new category for such lints at some point. We already have things like linting println! calls.

clippy_lints/src/dbg_macro.rs

rhysd · 2019-01-31T03:51:12Z

@mati865 @oli-obk

Thank you for the nice point. I found following SO question/answer and debug_assertions might be available to check it's run in release mode.

But I'm not sure actually. What do you think?

ghost · 2019-01-31T04:31:26Z

This lint is similar to use_debug and print_stdout whose purpose is "to catch debugging remnants". Based on that, I'd expect it to be a restriction lint that you enable on CI.

Also, maybe all three lints could be combined into a debugging_remnants lint.

ghost · 2019-01-31T04:47:51Z

I change my mind about my second point. You definitely wouldn't want to combine them.

rhysd · 2019-02-01T00:34:01Z

@oli-obk @mikerite @mati865

I changed category to 'restriction' and used suggestion. Though applicability is not machine-applicable. Could you review 7ec5528?

warning: `dbg!` macro is intended as a debugging tool
 --> foo.rs:2:5
  |
2 |     dbg!(42);
  |     ^^^^^^^^
  |
  = note: requested on the command line with `-W clippy::dbg-macro`
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#dbg_macro
help: ensure to avoid having uses of it in version control
  |
2 |     42;
  |     ^^

rhysd · 2019-02-01T02:31:36Z

Regarding to category, I'm having two options

'restriction' category which is disabled by default. Users are able to enable manually it by -W clippy::dbg_macro
'style' category which is enabled by default. And check it only when debug_assertion config is enabled in later pass. It means check is performed on only --release

I think 2. is potentially confusing since users would not expect that clippy changes its behavior looking release/debug mode.

oli-obk

I agree, the restriction category fits best for now

clippy_lints/src/dbg_macro.rs

tests/ui/dbg_macro.rs

rhysd · 2019-02-01T19:34:44Z

By adding new tests, I found two problems in current implementation.

At first, the token stream inserts a space between token and token:

warning: `dbg!` macro is intended as a debugging tool
  --> foo.rs:22:14
   |
22 |     foo(3) + dbg!(factorial(4));
   |              ^^^^^^^^^^^^^^^^^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#dbg_macro
help: ensure to avoid having uses of it in version control
   |
22 |     foo(3) + factorial ( 4 );
   |              ^^^^^^^^^^^^^^^

At second, if dbg!() is nested like dbg!(foo(dbg!(bar()))), dbg! is remaining in suggestion:

warning: `dbg!` macro is intended as a debugging tool
  --> foo.rs:21:5
   |
21 |     dbg!(dbg!(dbg!(42)));
   |     ^^^^^^^^^^^^^^^^^^^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#dbg_macro
help: ensure to avoid having uses of it in version control
   |
21 |     dbg ! ( dbg ! ( 42 ) );
   |     ^^^^^^^^^^^^^^^^^^^^^^

I think I should set "" to suggestion as @oli-obk suggested in review comment. If someone have any idea for workaround of above problems, please let me know..

rhysd · 2019-02-01T19:40:18Z

I also have found empty suggestion message does not work. When I tried to set String::new() at 6th argument of span_lint_and_sugg(), I got warning message as follows:

warning: `dbg!` macro is intended as a debugging tool
  --> foo.rs:23:14
   |
23 |     foo(3) + dbg!(factorial(4));
   |              ^^^^^^^^^^^^^^^^^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#dbg_macro
help: ensure to avoid having uses of it in version control
   |
23 |     foo(3) + ;
   |             --

rhysd · 2019-02-01T19:56:44Z

@oli-obk I used span_help_and_lint() to show both message and help, but not suggestion at 268ff85. And I added more tests at 54d49af. Could you review them again?

oli-obk · 2019-02-01T23:11:18Z

Instead of serializing the tokens you can use the snippet function on the span of the tokenstream. Then you get the actual text without the spaces

rhysd · 2019-02-03T09:30:13Z

clippy_lints/src/dbg_macro.rs

+                        mac.span,
+                        "`dbg!` macro is intended as a debugging tool",
+                        "ensure to avoid having uses of it in version control",
+                    );


I still used span_help_and_lint when snippet cannot be made from the token stream.

rhysd · 2019-02-03T09:34:41Z

@oli-obk Thank you for your suggestion. I read libsyntax implementation and found that retrieving first and last TokenTrees from TokenStream can make a span object enclosing entire the stream. At 3100fec I revived span_lint_and_sugg with snippet though still using span_help_and_lint when snippet is not available. Could you review the commit?

oli-obk · 2019-02-03T13:03:38Z

@bors r+

Thanks! this looks great to me now. Sorry about the tokentree thing, I wrongly thought there was a method to give you the span.

bors · 2019-02-03T13:03:39Z

📌 Commit 83d620b has been approved by oli-obk

bors · 2019-02-03T13:03:47Z

⌛ Testing commit 83d620b with merge 273b7f7...

Implement dbg_macro rule Fixes #3721 This patch adds new `dbg_macro` rule to check `dbg!` macro use. Since this is my first patch to clippy, I'm not confident about following points: - ~~Currently only checks `dbg!` span. Is it possible to check if the `dbg!` macro is provided by standard library or user-defined? If it's possible, I can make the check more strict.~~ Resolved as #3723 (comment) - ~~Is category `style` correct for this rule?~~'restriction' is used instead - ~~Should I use `span_lint_and_sugg` instead of `span_lint`? Currently entire message is put as `msg`. But later part `ensure to avoid having uses of it in version control` may be put as suggestion.~~ Done - I'm not native English speaker. The message and doc may not be natural as English.

bors · 2019-02-03T13:26:53Z

☀️ Test successful - checks-travis, status-appveyor
Approved by: oli-obk
Pushing 273b7f7 to master...

rhysd · 2019-02-03T14:15:49Z

@oli-obk No problem. It was a good chance to read a source of rustc compiler for me. Thank you for many code reviews!

implement dbg_macro rule (fixes rust-lang#3721)

f894adc

oli-obk reviewed Jan 30, 2019

View reviewed changes

phansch added the S-waiting-on-author Status: This is awaiting some action from the author. (Use `@rustbot ready` to update this status) label Jan 31, 2019

rhysd force-pushed the issue3721 branch from 5d9aec4 to f4500bb Compare February 1, 2019 00:27

fix category and use suggestion

7ec5528

rhysd force-pushed the issue3721 branch from f4500bb to 7ec5528 Compare February 1, 2019 00:31

add dbg_macro rule to CHANGELOG.md and update count in README

9d130a5

rhysd force-pushed the issue3721 branch from e86968f to 9d130a5 Compare February 1, 2019 02:32

rhysd added 2 commits February 1, 2019 11:40

remove TODO comment which was already done

06e4e9c

cargo +nightly fmt at clippy_lints/

b52a9bd

oli-obk reviewed Feb 1, 2019

View reviewed changes

clippy_lints/src/dbg_macro.rs Outdated Show resolved Hide resolved

tests/ui/dbg_macro.rs Show resolved Hide resolved

rhysd added 2 commits February 2, 2019 04:52

use span_help_and_lint() instead of span_lint_and_sugg()

268ff85

add more test cases for dbg_macro rule

54d49af

use snippet for making a suggestion if possible

3100fec

rhysd commented Feb 3, 2019

View reviewed changes

rhysd added 3 commits February 3, 2019 18:50

prefer if to match

60f723f

Merge branch 'master' into issue3721

4b736ff

run util/dev update_lints and cargo fmt --all

83d620b

rhysd force-pushed the issue3721 branch from 66064b3 to 83d620b Compare February 3, 2019 12:56

bors merged commit 83d620b into rust-lang:master Feb 3, 2019

thomaseizinger mentioned this pull request Feb 17, 2019

Remove dbg! macros from master (and prevent it) comit-network/comit-rs#760

Closed

dae mentioned this pull request Dec 13, 2021

Cap steps ankitects/anki#1548

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Implement dbg_macro rule #3723

Implement dbg_macro rule #3723

rhysd commented Jan 30, 2019 •

edited

Loading

mati865 commented Jan 30, 2019

oli-obk left a comment

oli-obk Jan 30, 2019

rhysd commented Jan 31, 2019

ghost commented Jan 31, 2019

ghost commented Jan 31, 2019

rhysd commented Feb 1, 2019 •

edited

Loading

rhysd commented Feb 1, 2019 •

edited

Loading

oli-obk left a comment

rhysd commented Feb 1, 2019

rhysd commented Feb 1, 2019

rhysd commented Feb 1, 2019

oli-obk commented Feb 1, 2019

rhysd Feb 3, 2019

rhysd commented Feb 3, 2019

oli-obk commented Feb 3, 2019

bors commented Feb 3, 2019

bors commented Feb 3, 2019

bors commented Feb 3, 2019

rhysd commented Feb 3, 2019

Implement dbg_macro rule #3723

Implement dbg_macro rule #3723

Conversation

rhysd commented Jan 30, 2019 • edited Loading

mati865 commented Jan 30, 2019

oli-obk left a comment

Choose a reason for hiding this comment

oli-obk Jan 30, 2019

Choose a reason for hiding this comment

rhysd commented Jan 31, 2019

ghost commented Jan 31, 2019

ghost commented Jan 31, 2019

rhysd commented Feb 1, 2019 • edited Loading

rhysd commented Feb 1, 2019 • edited Loading

oli-obk left a comment

Choose a reason for hiding this comment

rhysd commented Feb 1, 2019

rhysd commented Feb 1, 2019

rhysd commented Feb 1, 2019

oli-obk commented Feb 1, 2019

rhysd Feb 3, 2019

Choose a reason for hiding this comment

rhysd commented Feb 3, 2019

oli-obk commented Feb 3, 2019

bors commented Feb 3, 2019

bors commented Feb 3, 2019

bors commented Feb 3, 2019

rhysd commented Feb 3, 2019

rhysd commented Jan 30, 2019 •

edited

Loading

rhysd commented Feb 1, 2019 •

edited

Loading

rhysd commented Feb 1, 2019 •

edited

Loading