RFC: Implement @LINE macro #12727

ihnorton · 2015-08-21T04:56:30Z

(upated) Implements __LINE__ and __FILE__ magic macros returning the line number (integer) and filename (as string) for a given call location.

Fixes #8066

~~This is what happens when you force the riff-raff to learn a little scheme.~~

ihnorton · 2015-08-21T05:03:08Z

Alternatively, could use the same pattern just for __LINE__ (and also for __FILE__ to make the implementation a little bit more robust?)

timholy · 2015-08-21T09:39:44Z

This is what happens when you force the riff-raff to learn a little scheme.

Quote of the week!

ScottPJones · 2015-08-21T13:11:21Z

👏👏👏! 👍

StefanKarpinski · 2015-08-21T13:42:41Z

Nice. Probably needs a once over by @JeffBezanson

JeffBezanson · 2015-08-21T16:45:24Z

A LineNumberNode used as data should probably be wrapped in quote, since bits of the compiler might assume that LineNumberNodes don't execute, or can always be removed safely.

Wouldn't it be simpler just to replace @__LINE__ with the result of input-port-line at parse time?

ihnorton · 2015-08-21T18:08:21Z

That is much nicer. Updated to do so for both @__LINE__ and @__FILE__.

(I'm not sure how to document these now -- writing doc strings lead to a "Invalid doc expression" during sysimg build. Removed for now, will open a separate issue if I can't figure it out)

JeffBezanson · 2015-08-21T18:13:38Z

src/julia-parser.scm

-              (if (ts:space? s)
+              (cond
+                 ((eqv? head '__LINE__) (input-port-line (ts:port s)))
+                 ((eqv? head '__FILE__) `(call string (quote ,current-filename)))


Could just be a constant string, (string current-filename).

JeffBezanson · 2015-08-21T18:16:25Z

I'm not 100% sure how to make this doc-able either. Maybe we should parse @__LINE__ as (macrocall @__LINE__ 42). Then we could define it as an identity macro and document it there.

mbauman · 2015-08-21T20:08:38Z

This is awesome. You could document them as keywords, which are checked first:

julia> Base.Docs.keywords[symbol("@__FILE__")] = "filedoc"
"filedoc"

help?> @__FILE__
search: @__FILE__

"filedoc"

ihnorton · 2015-08-22T02:13:09Z

Perfect, thanks @mbauman. Updated.

Implementing @__FILE__ this way changes the result when used in include_string(..., fake_filename) ... It seems unlikely that anyone relies on this behavior, but I will revert that change if there are any objections.

JeffBezanson · 2015-08-22T02:48:55Z

A filename gets passed through from include_string to jl-parse-string-stream, so I think it's possible to still get the right filename. Is that not happening?

stevengj · 2015-08-22T12:43:54Z

@ihnorton, I think IJulia relies on the @__FILE__ behavior for include_string(..., fake_filename), where fake_filename is e.g. "In[23]", in order to get useful backtraces etc.

stevengj · 2015-08-22T12:45:43Z

test/loading.jl

+thefname = "the fname!//\\&\1*"
+# passing a second argument to include_string should be reflected by @__FILE__
+@test include_string("test_atsign_file() = @__FILE__", thefname)() == thefname
+@test include_string("test_atsign_file() = @__FILE__")() == "string"


No test for @__LINE__?

ihnorton · 2015-08-22T17:33:06Z

Sorry, I misunderstood what was going on with the test failure. This does not change the behavior of include_string at all, but rather of @__FILE__. include_string(..., filename) still works fine. The change is that now @__FILE__ actually reflects the filename that the parser sees (such as the argument to include_string). This feels arguably more accurate.

with /tmp/foo.jl as:

println(include_string("@__FILE__", "foo"))
println(Base.source_path())

on master the out of julia /tmp/foo.jl is:

/tmp/foo.jl
/tmp/foo.jl

on this branch:

foo
/tmp/foo.jl

There are only two packages that use include_string -- IJulia and Jewel -- and their usage should still work fine. On the other hand, a large number of packages use @__FILE__. I don't know of any other code path whereby @__FILE__ would not equal Base.source_path, but it is possible that this change could break some code.

Fixes JuliaLang#8066

ihnorton · 2015-08-27T22:40:07Z

I removed the @__FILE__ change for now. Will merge soon if there are no objections.

ihnorton · 2015-08-27T22:41:01Z

... or not, I guess. Just saw the feature freeze announcement.

tkelman · 2015-08-27T23:09:29Z

base/docs/helpdb.jl

    @__FILE__() -> AbstractString

-`@__FILE__` expands to a string with the absolute path and file name of the script being run. Returns `nothing` if run from a REPL or an empty string if evaluated by `julia -e <expr>`.
+`@__FILE__` expands to a string with the absolute path and file name of the script being run.
+Returns `"none"` if run from a REPL or command-line context.


Did this actually change from nothing to "none" here?

@ihnorton can you confirm? Just tried it and this looks wrong.

Yeah that was left from the proposed change. I'll fix the doc.
On Aug 28, 2015 7:35 PM, "Tony Kelman" notifications@github.com wrote:

In base/docs/helpdb.jl
#12727 (comment):

@__FILE__() -> AbstractString

-@__FILE__ expands to a string with the absolute path and file name of the script being run. Returns nothing if run from a REPL or an empty string if evaluated by julia -e <expr>.
+@__FILE__ expands to a string with the absolute path and file name of the script being run.
+Returns "none" if run from a REPL or command-line context.

@ihnorton https://github.com/ihnorton can you confirm? Just tried it
and this looks wrong.

—
Reply to this email directly or view it on GitHub
https://github.com/JuliaLang/julia/pull/12727/files#r38254310.

8fb7046 (on the docfix branch)

RFC: Implement @__LINE__ macro

StefanKarpinski · 2015-08-28T14:47:48Z

Let's just pretend this got merged before that announcement.

ihnorton changed the title ~~RFC: Implement @__LOCATION__ magic macro~~ RFC: Implement @__LINE__ and @__FILE__ macros Aug 21, 2015

ihnorton force-pushed the on-location branch from df724cc to 5e43774 Compare August 21, 2015 18:02

JeffBezanson reviewed Aug 21, 2015
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ihnorton force-pushed the on-location branch from 5e43774 to bc5ae98 Compare August 22, 2015 02:09

ihnorton force-pushed the on-location branch from bc5ae98 to fc647fe Compare August 22, 2015 05:17

stevengj reviewed Aug 22, 2015
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ihnorton mentioned this pull request Aug 24, 2015

Emit inlining information to improve line numbers #12544

Merged

ihnorton changed the title ~~RFC: Implement @__LINE__ and @__FILE__ macros~~ RFC: Implement @__LINE__ macro Aug 27, 2015

Implement __LINE__ magic macros

eee075c

Fixes JuliaLang#8066

ihnorton force-pushed the on-location branch from fc647fe to eee075c Compare August 27, 2015 22:38

tkelman reviewed Aug 27, 2015
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StefanKarpinski added a commit that referenced this pull request Aug 28, 2015

Merge pull request #12727 from ihnorton/on-location

a4c2916

RFC: Implement @__LINE__ macro

StefanKarpinski merged commit a4c2916 into JuliaLang:master Aug 28, 2015

ihnorton added a commit that referenced this pull request Aug 29, 2015

Correct docstring for @__FILE__ ref #12727

40b025b

ihnorton added a commit that referenced this pull request Aug 29, 2015

Correct docstring for @__FILE__ ref #12727

8fb7046

ihnorton added a commit that referenced this pull request Sep 4, 2015

Correct docstring for @__FILE__ ref #12727

babb251

ihnorton added a commit that referenced this pull request Sep 4, 2015

Correct docstring for @__FILE__ ref #12727

c1b2cd7

ihnorton deleted the on-location branch September 13, 2015 16:19

shashi mentioned this pull request Jan 30, 2017

Debugging: Line numbers and originating signal JuliaGizmos/Reactive.jl#118

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RFC: Implement @LINE macro #12727

RFC: Implement @LINE macro #12727

ihnorton commented Aug 21, 2015

ihnorton commented Aug 21, 2015

timholy commented Aug 21, 2015

ScottPJones commented Aug 21, 2015

StefanKarpinski commented Aug 21, 2015

JeffBezanson commented Aug 21, 2015

ihnorton commented Aug 21, 2015

JeffBezanson Aug 21, 2015

JeffBezanson commented Aug 21, 2015

mbauman commented Aug 21, 2015

ihnorton commented Aug 22, 2015

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stevengj Aug 22, 2015

ihnorton commented Aug 22, 2015

ihnorton commented Aug 27, 2015

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tkelman Aug 27, 2015

tkelman Aug 28, 2015

ihnorton Aug 29, 2015

ihnorton Aug 29, 2015

StefanKarpinski commented Aug 28, 2015

RFC: Implement @__LINE__ macro #12727

RFC: Implement @__LINE__ macro #12727

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ihnorton commented Aug 21, 2015

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StefanKarpinski commented Aug 28, 2015

RFC: Implement @LINE macro #12727

RFC: Implement @LINE macro #12727