summaryrefslogtreecommitdiff
path: root/src/compiler/scala/tools/nsc/typechecker/Checkable.scala
Commit message (Collapse)AuthorAgeFilesLines
* SI-7301 Make tuple classes finalStefan Zeiger2016-07-071-3/+1
| | | | | This includes undoing the special case for `-Xfuture` introduced in https://github.com/scala/scala/pull/2299 and updating tests to take the new errors into account.
* Merge remote-tracking branch 'origin/2.11.x' into 2.12.xSeth Tisue2015-08-201-1/+1
|\ | | | | | | | | | | | | | | | | | | all conflicts were because the changes changed code that doesn't exist anymore in 2.12; they were resolved with `git checkout --ours` c201eac changed bincompat-forward.whitelist.conf but I dropped the change in this merge because it refers to AbstractPromise which no longer exists in 2.12
| * ScalaDoc fixes for compilerJanek Bogucki2015-07-291-1/+1
| |
* | SI-9408 Record known subclasses of local classesJason Zaugg2015-07-231-2/+2
|/ | | | | | | | | | | | | | Using the same facility that we use to record subclasses of sealed classes, record the subclasses of term-owned ("local") classes. I have changed existing callers of `children` to use `sealedChildren` so we don't start using this new information in pattern matching and type pattern checkability analysis. The following commit will build on this to infer finality of local classes in the context of outer pointer elision in the constructors phase.
* SI-8597 Expand documentation of CheckabilityCheckerJason Zaugg2014-11-181-1/+22
| | | | Cherry picking some of the previous commit message.
* SI-8597 Improved pattern unchecked warningsJason Zaugg2014-11-091-4/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The spec says that `case _: List[Int]` should be always issue an unchecked warning: > Types which are not of one of the forms described above are > also accepted as type patterns. However, such type patterns > will be translated to their erasure (§3.7). The Scala compiler > will issue an “unchecked” warning for these patterns to flag > the possible loss of type-safety. But the implementation goes a little further to omit warnings based on the static type of the scrutinee. As a trivial example: def foo(s: Seq[Int]) = s match { case _: List[Int] => } need not issue this warning. These discriminating unchecked warnings are domain of `CheckabilityChecker`. Let's deconstruct the reported bug: def nowarn[T] = (null: Any) match { case _: Some[T] => } We used to determine that if the first case matched, the scrutinee type would be `Some[Any]` (`Some` is covariant). If this statically matches `Some[T]` in a pattern context, we don't need to issue an unchecked warning. But, our blanket use of `existentialAbstraction` in `matchesPattern` loosened the pattern type to `Some[Any]`, and the scrutinee type was deemed compatible. I've added a new method, `scrutConformsToPatternType` which replaces pattern type variables by wildcards, but leaves other abstract types intact in the pattern type. We have to use this inside `CheckabilityChecker` only. If we were to make `matchesPattern` stricter in the same way, tests like `pos/t2486.scala` would fail. I have introduced a new symbol test to (try to) identify pattern type variables introduced by `typedBind`. Its not pretty, and it might be cleaner to reserve a new flag for these. I've also included a test variation exercising with nested matches. The pattern type of the inner case can't, syntactically, refer to the pattern type variable of the enclosing case. If it could, we would have to be more selective in our wildcarding in `ptMatchesPatternType` by restricting ourselves to type variables associated with the closest enclosing `CaseDef`. As some further validation of the correctness of this patch, four stray warnings have been teased out of neg/unchecked-abstract.scala I also had to changes `typeArgsInTopLevelType` to extract the type arguments of `Array[T]` if `T` is an abstract type. This avoids the "Checkability checker says 'Uncheckable', but uncheckable type cannot be found" warning and consequent overly lenient analysis. Without this change, the warning was suppressed for: def warnArray[T] = (null: Any) match { case _: Array[T] => }
* Rip out reporting indirection from CompilationUnitAdriaan Moors2014-07-041-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Inline the forwarders from CompilationUnit, which should not affect behavior. Since all forwarders lead to global.reporter, don't first navigate to a compilation unit, only to then forward back to global.reporter. The cleanup in the previous commits revealed a ton of confusion regarding how to report an error. This was a mechanical search/replace, which has low potential for messing things up, since the list of available methods are disjoint between `reporter` and `currentRun.reporting`. The changes involving `typer.context` were done previously. Essentially, there are three ways to report: - via typer.context, so that reporting can be silenced (buffered) - via global.currentRun.reporting, which summarizes (e.g., deprecation) - via global.reporter, which is (mostly) stateless and straightforward. Ideally, these should all just go through `global.currentRun.reporting`, with the typing context changing that reporter to buffer where necessary. After the refactor, these are the ways in which we report (outside of typer): - reporter.comment - reporter.echo - reporter.error - reporter.warning - currentRun.reporting.deprecationWarning - currentRun.reporting.incompleteHandled - currentRun.reporting.incompleteInputError - currentRun.reporting.inlinerWarning - currentRun.reporting.uncheckedWarning Before: - c.cunit.error - c.enclosingUnit.deprecationWarning - context.unit.error - context.unit.warning - csymCompUnit.warning - cunit.error - cunit.warning - currentClass.cunit.warning - currentIClazz.cunit.inlinerWarning - currentRun.currentUnit.error - currentRun.reporting - currentUnit.deprecationWarning - currentUnit.error - currentUnit.warning - getContext.unit.warning - getCurrentCUnit.error - global.currentUnit.uncheckedWarning - global.currentUnit.warning - global.reporter - icls.cunit.warning - item.cunit.warning - reporter.comment - reporter.echo - reporter.error - reporter.warning - reporting.deprecationWarning - reporting.incompleteHandled - reporting.incompleteInputError - reporting.inlinerWarning - reporting.uncheckedWarning - typer.context.unit.warning - unit.deprecationWarning - unit.echo - unit.error - unit.incompleteHandled - unit.incompleteInputError - unit.uncheckedWarning - unit.warning - v1.cunit.warning All these methods ended up calling a method on `global.reporter` or on `global.currentRun.reporting` (their interfaces are disjoint). Also clean up `TypeDiagnostics`: inline nearly-single-use private methods.
* SI-8324 Fix regression in override checks for sealed classesJason Zaugg2014-02-221-1/+1
| | | | | | | | | | | | adeffda25 changed `Symbol#isEffectivelyFinal` to help the optimizer by inferring finality within sealed class hierarchies. However, this change wasn't neccesarily welcome for other clients of that method. In the enclosed test case, we see that overriding checks in `RefChecks` regressed. This commit moves the enhanced version into a new method and selectively uses it in the optimizer (and the tail call optimizer).
* SI-8143 Regressions with override checks, private membersJason Zaugg2014-01-141-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | These regressed in e609f1f20b, which excluded all private methods from overriding checks. We should only exclude private[this] members on the low end of a pair, as was done before that commit, and, we must also exclude private members on the high side. Why? Warning: reverse engineered intuition follows. We need to report an error when if a private method in a subclass has matches a less-private method in the super class and report an error, lest the user be fooled into thinking it might be invoked virtually. On the other hand, adding a private method to a super class shouldn't invalidate the choice names of public members in its superclasses. I've removed the test case added by that commit and will lodge a reworked version of it that Paul provided as a new issue. That shows a bug with qualified private + inheritance. In addition, the expectation of `neg/accesses.check` is reverted to its 2.10.3 version, which I believe is correct. When it was changed in e609f1f20b it sprouted a variation, `neg/accesses-2`, which has now changed behaviour. The intent of that test will be captured in the aforementioned issue covering qualified private inheritance.
* SI-7984 Issue unchecked warning for type aliasesJason Zaugg2013-11-261-5/+7
| | | | | | - Dealias pattern types before launching the CheckabilityChecker - Sharpen the error messages to explain that the dealiased type is the expansion of the alias.
* Logging cleanup.Paul Phillips2013-08-251-1/+3
| | | | | | | | | | | | | | Reduced the amount of extraneous logging noise at the default logging level. Was brought to my usual crashing halt by the discovery of identical logging statements throughout GenASM and elsewhere. I'm supposing the reason people so grossly underestimate the cost of such duplication is that most of the effects are in things which don't happen, aka "silent evidence". An example of a thing which isn't happening is the remainder of this commit, which exists only in parallel universes.
* Add checkability condition.Paul Phillips2013-08-171-2/+4
| | | | | All parents of an intersection type must be checkable for the type to be checkable.
* Concision contribution.Paul Phillips2013-05-231-1/+1
| | | | | | | | | | | | | | | | | | | | | We have lots of core classes for which we need not go through the symbol to get the type: ObjectClass.tpe -> ObjectTpe AnyClass.tpe -> AnyTpe I updated everything to use the concise/direct version, and eliminated a bunch of noise where places were calling typeConstructor, erasedTypeRef, and other different-seeming methods only to always wind up with the same type they would have received from sym.tpe. There's only one Object type, before or after erasure, with or without type arguments. Calls to typeConstructor were especially damaging because (see previous commit) it had a tendency to cache a different type than the type one would find via other means. The two types would compare =:=, but possibly not == and definitely not eq. (I still don't understand what == is expected to do with types.)
* SI-7261 Implicit conversion of BooleanSetting to Boolean and BooleanFlagSom Snytt2013-03-271-1/+1
| | | | | | | This commit shortens expressions of the form `if (settings.debug.value)` to `if (settings.debug)` for various settings. Rarely, the setting is supplied as a method argument. The conversion is not employed in simple definitions where the Boolean type would have to be specified.
* SI-7294 Treat TupleN as final under -XfutureJason Zaugg2013-03-241-2/+9
| | | | | | | | | | | | | | | For the purposes of checkability warnings. This will warn in case of: scala> (1, 2) match { case Seq() => 0; case _ => 1 } res9: Int = 1 Given how often Tuples are used as scrutinees, this is a highly desirable place to warn. I was orginally going to unlock this under -Xlint, and could be easily convinced to go that way, given that -Xfuture is a less popular option.
* Cleaning up dummy applied types and friends.Paul Phillips2013-01-261-2/+5
| | | | Incorporates feedback from dealias/widen PR.
* Incorporated Variance value class in Variances.Paul Phillips2013-01-091-5/+6
| | | | | No one will ever know what it took for me to refine Variances into its current condition. A LONELY QUEST.
* Added -Xdev setting... you know, for devsPaul Phillips2012-11-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | A setting we developers can give all the time and expect to hear useful things without being buried in debugging output. As the comment says: This is for WARNINGS which should reach the ears of scala developers whenever they occur, but are not useful for normal users. They should be precise, explanatory, and infrequent. Please don't use this as a logging mechanism. !!! is prefixed to all messages issued via this route to make them visually distinct. This is what I always intended for "debugwarn", the method I have deprecated in favor of the more accurate: def devWarning(msg: => String): Unit In this VERY SAME COMMIT, I performed the CLOSELY RELATED task of quieting down an -Xlint warning which had become too noisy thanks to implicit classes tickling it. I tightened that warn condition to include both -Xlint and -Xdev.
* Removed unused imports.Paul Phillips2012-11-061-5/+1
| | | | | | | | | A dizzying number of unused imports, limited to files in src/compiler. I especially like that the unused import option (not quite ready for checkin itself) finds places where feature implicits have been imported which are no longer necessary, e.g. this commit includes half a dozen removals of "import scala.language.implicitConversions".
* Merge commit 'refs/pull/1574/head' into merge-210Paul Phillips2012-11-051-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * commit 'refs/pull/1574/head': (24 commits) Fixing issue where OSGi bundles weren't getting used for distribution. Fixes example in Type.asSeenFrom Fix for SI-6600, regression with ScalaNumber. SI-6562 Fix crash with class nested in @inline method Brings copyrights in Scaladoc footer and manpage up-to-date, from 2011/12 to 2013 Brings all copyrights (in comments) up-to-date, from 2011/12 to 2013 SI-6606 Drops new icons in, replaces abstract types placeholder icons SI-6132 Revisited, cleaned-up, links fixed, spelling errors fixed, rewordings Labeling scala.reflect and scala.reflect.macros experimental in the API docs Typo-fix in scala.concurrent.Future, thanks to @pavelpavlov Remove implementation details from Position (they are still under reflection.internal). It probably needs more cleanup of the api wrt to ranges etc but let's leave it for later SI-6399 Adds API docs for Any and AnyVal Removing actors-migration from main repository so it can live on elsewhere. Fix for SI-6597, implicit case class crasher. SI-6578 Harden against synthetics being added more than once. SI-6556 no assert for surprising ctor result type Removing actors-migration from main repository so it can live on elsewhere. Fixes SI-6500 by making erasure more regular. Modification to SI-6534 patch. Fixes SI-6559 - StringContext not using passed in escape function. ... Conflicts: src/actors-migration/scala/actors/migration/StashingActor.scala src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala src/compiler/scala/tools/nsc/settings/AestheticSettings.scala src/compiler/scala/tools/nsc/transform/Erasure.scala src/library/scala/Application.scala src/library/scala/collection/immutable/GenIterable.scala.disabled src/library/scala/collection/immutable/GenMap.scala.disabled src/library/scala/collection/immutable/GenSeq.scala.disabled src/library/scala/collection/immutable/GenSet.scala.disabled src/library/scala/collection/immutable/GenTraversable.scala.disabled src/library/scala/collection/mutable/GenIterable.scala.disabled src/library/scala/collection/mutable/GenMap.scala.disabled src/library/scala/collection/mutable/GenSeq.scala.disabled src/library/scala/collection/mutable/GenSet.scala.disabled src/library/scala/collection/mutable/GenTraversable.scala.disabled src/library/scala/collection/parallel/immutable/ParNumericRange.scala.disabled
| * Brings all copyrights (in comments) up-to-date, from 2011/12 to 2013Heather Miller2012-11-021-1/+1
| |
* | Merge branch 'merge-2.10.0-wip' into merge-2.10.xPaul Phillips2012-10-311-34/+33
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * merge-2.10.0-wip: Use Typed rather than .setType Wider use and a new variant of typedPos. SI-6575 Plug inference leak of AbstractPartialFun Remove compiler phases that don't influence scaladoc generation. Disabled generation of _1, _2, etc. methods. SI-6526 Additional test case. Fix SI-6552, regression with self types. avoid single-art assert where harmful in duration-tck Fix for SI-6537, inaccurate unchecked warning. Crash on missing accessor (internal bug in the lazy vals implementation) instead of trying to recover from the bug Incorporated changes suggested in code review Added one more test for SI-6358 Closes SI-6358. Move accessor generation for lazy vals to typers. SI-6526 Tail call elimination should descend deeper. Remove unneeded calls to substring() Changes Tree and Type members from vals to defs. Scaladoc knows the package structure of the libraries, so don't include them in external documentation setting. Fixes SI-6170: issue with dragging scaladoc splitter over central iframe Added a Swing ColorChooser wrapper Added a Swing PopupMenu wrapper Conflicts: src/compiler/scala/reflect/reify/phases/Reshape.scala src/compiler/scala/tools/nsc/typechecker/Duplicators.scala src/continuations/plugin/scala/tools/selectivecps/SelectiveCPSTransform.scala src/reflect/scala/reflect/internal/Types.scala test/files/neg/unchecked-knowable.check
| * Fix for SI-6537, inaccurate unchecked warning.Paul Phillips2012-10-181-34/+33
| | | | | | | | | | | | | | | | I found a more direct expression of the unchecked logic, which should be much easier for others to verify. But the bug being fixed here is that the unchecked checking happens too early, and the sealed children of a symbol are not yet visible if it is being simultaneously compiled.
* | Removed redundant containsUncheckable.Paul Phillips2012-10-111-0/+12
|/ | | | | | | | Like the comment said: "TODO: at the very least, reduce duplication wrt checkCheckable" I went with the very most, eliminating it.
* Added logic and tests for unchecked refinements.Paul Phillips2012-09-271-4/+20
|
* Nailed down the "impossible match" logic.Paul Phillips2012-09-271-28/+49
| | | | | | | | | | | | | | | | | | I will again defer to a comment. /** Given classes A and B, can it be shown that nothing which is * an A will ever be a subclass of something which is a B? This * entails not only showing that !(A isSubClass B) but that the * same is true of all their subclasses. Restated for symmetry: * the same value cannot be a member of both A and B. * * 1) A must not be a subclass of B, nor B of A (the trivial check) * 2) One of A or B must be completely knowable (see isKnowable) * 3) Assuming A is knowable, the proposition is true if * !(A' isSubClass B) for all A', where A' is a subclass of A. * * Due to symmetry, the last condition applies as well in reverse. */
* Restored warning for impossible type tests.Paul Phillips2012-09-261-9/+31
| | | | | | | | | | | I had this in before, then removed it since it is sometimes redundant with an error message later issued by the pattern matcher (e.g. scrutinee is incompatible with pattern type.) However it also catches a lot of cases which are not errors, so I think the modest redundancy is tolerable for now. I also enhanced the logic for recognizing impossible type tests, taking sealedness into account.
* Annotate non local returns with @unchecked.Paul Phillips2012-09-261-8/+1
| | | | | Newly available @unchecked annotation enables removing the special case from the unchecked logic.
* Improvements to unchecked warnings.Paul Phillips2012-09-251-88/+166
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Closes SI-6275, SI-5762. The comment says is better than I can. /** On pattern matcher checkability: * * Consider a pattern match of this form: (x: X) match { case _: P => } * * There are four possibilities to consider: * [P1] X will always conform to P * [P2] x will never conform to P * [P3] X <: P if some runtime test is true * [P4] X cannot be checked against P * * The first two cases correspond to those when there is enough static * information to say X <: P or that !(X <: P) for all X and P. * The fourth case includes unknown abstract types or structural * refinements appearing within a pattern. * * The third case is the interesting one. We designate another type, XR, * which is essentially the intersection of X and |P|, where |P| is * the erasure of P. If XR <: P, then no warning is emitted. * * Examples of how this info is put to use: * sealed trait A[T] ; class B[T] extends A[T] * def f(x: B[Int]) = x match { case _: A[Int] if true => } * def g(x: A[Int]) = x match { case _: B[Int] => } * * `f` requires no warning because X=B[Int], P=A[Int], and B[Int] <:< A[Int]. * `g` requires no warning because X=A[Int], P=B[Int], XR=B[Int], and B[Int] <:< B[Int]. * XR=B[Int] because a value of type A[Int] which is tested to be a B can * only be a B[Int], due to the definition of B (B[T] extends A[T].) * * This is something like asSeenFrom, only rather than asking what a type looks * like from the point of view of one of its base classes, we ask what it looks * like from the point of view of one of its subclasses. */
* Move checkCheckable out of Infer.Paul Phillips2012-09-251-0/+154
Preparing for separate file with checkability logic.