REPL summarizes warnings

[som-snytt]

Emit the summary "there were deprecations" after
successful parse.

Tweaks #7482

Previously, fatal warning trumped incomplete input, so switch that around. Previously:

Welcome to Scala 2.13.0-20190213-233114-f1c1d62 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_144).
Type in expressions for evaluation. Or try :help.

scala> def f() = { 'abc
                   ^
       warning: symbol literal is deprecated; use sym"abc" instead
error: No warnings can be incurred under -Xfatal-warnings.

Wait for complete input to issue summary.

Summary, -deprecation, -Xfatal-warnings:

$ skala -feature

     ________ ___   / /  ___
    / __/ __// _ | / /  / _ |
  __\ \/ /__/ __ |/ /__/ __ |
 /____/\___/_/ |_/____/_/ | |
                          |/  version 2.13.0-20190213-233114-f1c1d62

scala> 'abc
warning: there was one deprecation warning (since 2.13.0); for details, enable `:setting -deprecation' or `:replay -deprecation'
res0: Symbol = 'abc

scala> trait T { def f() }
warning: there was one deprecation warning (since 2.13.0); for details, enable `:setting -deprecation' or `:replay -deprecation'
defined trait T

scala> :replay -deprecation
replay> 'abc
        ^
        warning: symbol literal is deprecated; use sym"abc" instead
res0: Symbol = 'abc

replay> trait T { def f() }
                         ^
        warning: procedure syntax is deprecated: instead, add `: Unit` to explicitly declare `f`'s return type
defined trait T


scala> :replay -Xsource:2.14
replay> 'abc
        ^
        error: symbol literal is unsupported; use sym"abc" instead

replay> trait T { def f() }
                         ^
        error: procedure syntax is unsupported: instead, add `: Unit` to explicitly declare `f`'s return type


scala> :quit

Fixes scala/bug#11402

[SethTisue]

I've moved this to the 2.13.1 milestone since it isn't really a release blocker, but it would certainly be very good to have this fixed.

[som-snytt]

and have 2 and 2002 different commits each, respectively.

[som-snytt]

Very tough to reason about a stew of side effects. I had even forgotten who tells global what is the current run. (Answer is the current run.)

This fix is to remove reporter.reset mole-whacking. It's reset after getting a parsable unit, so you only see parse warnings once; and it's reset after compiling the line, and in addition the conditional warnings are cleared, because otherwise they hang around while parsing the next line, since parsing doesn't create a new run. Note that reporter is also reset by global before compiling as well; there are currently two compilations per line for $read and $eval containers.

[dwijnand]

The change sounds good and the diff looks reasonable, and all the tests are passing. I think it would be good to capture this as a test no? I don't exactly see the behaviour you describe in the transcript in the PR description in any of the changed tests.

[som-snytt]

The updated check files demonstrate parser-based deprecations warning is shown now.

I'll see if a repl test will show the multiline case not warning on every line, see the comment from last Valentine's.

[som-snytt]

With deprecation enabled:

     ________ ___   / /  ___
    / __/ __// _ | / /  / _ |
  __\ \/ /__/ __ |/ /__/ __ |
 /____/\___/_/ |_/____/_/ | |
                          |/  version 2.13.2-20200202-014822-0e6426d

scala> def f = {
     | val x = 'abc
       val x = 'abc
               ^
On line 2: warning: symbol literal is deprecated; use Symbol("abc") instead
     | val y = x.toString
     | y
     | }
def f: String

scala> :quit

versus

Welcome to Scala 2.13.1 (OpenJDK 64-Bit Server VM, Java 11.0.5).
Type in expressions for evaluation. Or try :help.

scala> def f = {
     | val x = 'abc
       val x = 'abc
               ^
On line 2: warning: symbol literal is deprecated; use Symbol("abc") instead
     | val y = x.toString
       val x = 'abc
               ^
On line 2: warning: symbol literal is deprecated; use Symbol("abc") instead
     | y
       val x = 'abc
               ^
On line 2: warning: symbol literal is deprecated; use Symbol("abc") instead
     | }
       val x = 'abc
               ^
On line 2: warning: symbol literal is deprecated; use Symbol("abc") instead
f: String

scala> :quit

[dwijnand]

Thanks!

[som-snytt]

Note that SessionTest doesn't handle mid-input feedback from parser.