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-rw-r--r--src/compiler/scala/tools/nsc/settings/StandardScalaSettings.scala2
-rw-r--r--src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala2
-rw-r--r--src/compiler/scala/tools/nsc/typechecker/Infer.scala23
-rw-r--r--src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala2
-rw-r--r--src/compiler/scala/tools/nsc/typechecker/Typers.scala2
-rw-r--r--src/library/scala/unchecked.scala42
-rw-r--r--src/reflect/scala/reflect/internal/TreeInfo.scala3
-rw-r--r--test/files/neg/t3692-new.check18
-rw-r--r--test/files/neg/t3692-old.check31
-rw-r--r--test/files/neg/unchecked-suppress.check10
-rw-r--r--test/files/neg/unchecked-suppress.flags1
-rw-r--r--test/files/neg/unchecked-suppress.scala10
12 files changed, 93 insertions, 53 deletions
diff --git a/src/compiler/scala/tools/nsc/settings/StandardScalaSettings.scala b/src/compiler/scala/tools/nsc/settings/StandardScalaSettings.scala
index 0991577829..ee26bb2817 100644
--- a/src/compiler/scala/tools/nsc/settings/StandardScalaSettings.scala
+++ b/src/compiler/scala/tools/nsc/settings/StandardScalaSettings.scala
@@ -43,7 +43,7 @@ trait StandardScalaSettings {
val target = ChoiceSetting ("-target", "target", "Target platform for object files. All JVM 1.5 targets are deprecated.",
List("jvm-1.5", "jvm-1.5-fjbg", "jvm-1.5-asm", "jvm-1.6", "jvm-1.7", "msil"),
"jvm-1.6")
- val unchecked = BooleanSetting ("-unchecked", "Enable detailed unchecked (erasure) warnings.")
+ val unchecked = BooleanSetting ("-unchecked", "Enable additional warnings where generated code depends on assumptions.")
val uniqid = BooleanSetting ("-uniqid", "Uniquely tag all identifiers in debugging output.")
val usejavacp = BooleanSetting ("-usejavacp", "Utilize the java.class.path in classpath resolution.")
val verbose = BooleanSetting ("-verbose", "Output messages about what the compiler is doing.")
diff --git a/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala b/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala
index 1f7c34b8ad..f0979978b0 100644
--- a/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala
+++ b/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala
@@ -416,7 +416,7 @@ abstract class ExplicitOuter extends InfoTransform
val (checkExhaustive, requireSwitch) = nselector match {
case Typed(nselector1, tpt) =>
- val unchecked = treeInfo.isUncheckedAnnotation(tpt.tpe)
+ val unchecked = tpt.tpe hasAnnotation UncheckedClass
if (unchecked)
nselector = nselector1
diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
index e096b75d6d..3be4a46a79 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
@@ -1366,14 +1366,16 @@ trait Infer {
else if (param.isContravariant) >:>
else =:=
)
- val TypeRef(_, sym, args) = arg
-
- ( isLocalBinding(sym)
- || arg.typeSymbol.isTypeParameterOrSkolem
- || (sym.name == tpnme.WILDCARD) // avoid spurious warnings on HK types
- || check(arg, param.tpe, conforms)
- || warn("non-variable type argument " + arg)
- )
+ (arg hasAnnotation UncheckedClass) || {
+ val TypeRef(_, sym, args) = arg.withoutAnnotations
+
+ ( isLocalBinding(sym)
+ || arg.typeSymbol.isTypeParameterOrSkolem
+ || (sym.name == tpnme.WILDCARD) // avoid spurious warnings on HK types
+ || check(arg, param.tpe, conforms)
+ || warn("non-variable type argument " + arg)
+ )
+ }
}
// Checking if pt (the expected type of the pattern, and the type
@@ -1404,8 +1406,11 @@ trait Infer {
case _ =>
def where = ( if (inPattern) "pattern " else "" ) + typeToTest
if (check(typeToTest, typeEnsured, =:=)) ()
+ // Note that this is a regular warning, not an uncheckedWarning,
+ // which is now the province of such notifications as "pattern matcher
+ // exceeded its analysis budget."
else warningMessages foreach (m =>
- context.unit.uncheckedWarning(tree.pos, s"$m in type $where is unchecked since it is eliminated by erasure"))
+ context.unit.warning(tree.pos, s"$m in type $where is unchecked since it is eliminated by erasure"))
}
}
diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala
index cf5c7265ad..dbb3067bf6 100644
--- a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala
@@ -1228,7 +1228,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
if (settings.XnoPatmatAnalysis.value) (true, false)
else scrut match {
case Typed(_, tpt) =>
- (treeInfo.isUncheckedAnnotation(tpt.tpe),
+ (tpt.tpe hasAnnotation UncheckedClass,
// matches with two or fewer cases need not apply for switchiness (if-then-else will do)
treeInfo.isSwitchAnnotation(tpt.tpe) && casesNoSubstOnly.lengthCompare(2) > 0)
case _ =>
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index b1c3249e35..87a1923df4 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -3211,7 +3211,7 @@ trait Typers extends Modes with Adaptations with Tags {
// we don't create a new Context for a Match, so find the CaseDef, then go out one level and navigate back to the match that has this case
// val thisCase = context.nextEnclosing(_.tree.isInstanceOf[CaseDef])
// val unchecked = thisCase.outer.tree.collect{case Match(selector, cases) if cases contains thisCase => selector} match {
- // case List(Typed(_, tpt)) if treeInfo.isUncheckedAnnotation(tpt.tpe) => true
+ // case List(Typed(_, tpt)) if tpt.tpe hasAnnotation UncheckedClass => true
// case t => println("outer tree: "+ (t, thisCase, thisCase.outer.tree)); false
// }
// println("wrapClassTagUnapply"+ (!isPastTyper && infer.containsUnchecked(pt), pt, uncheckedPattern))
diff --git a/src/library/scala/unchecked.scala b/src/library/scala/unchecked.scala
index 10d34312cf..5b05792d97 100644
--- a/src/library/scala/unchecked.scala
+++ b/src/library/scala/unchecked.scala
@@ -6,32 +6,30 @@
** |/ **
\* */
-
-
package scala
-/** An annotation that gets applied to a selector in a match expression.
- * If it is present, exhaustiveness warnings for that expression will be
- * suppressed.
- * For example, compiling the code:
+/** An annotation to designate that the annotated entity
+ * should not be considered for additional compiler checks.
+ * Specific applications include annotating the subject of
+ * a match expression to suppress exhaustiveness warnings, and
+ * annotating a type argument in a match case to suppress
+ * unchecked warnings.
+ *
+ * Such suppression should be used with caution, without which
+ * one may encounter [[scala.MatchError]] or [[java.lang.ClassCastException]]
+ * at runtime. In most cases one can and should address the
+ * warning instead of suppressing it.
+ *
* {{{
- * object test extends App {
- * def f(x: Option[Int]) = x match {
- * case Some(y) => y
- * }
- * f(None)
+ * object Test extends App {
+ * // This would normally warn "match is not exhaustive"
+ * // because `None` is not covered.
+ * def f(x: Option[String]) = (x: @unchecked) match { case Some(y) => y }
+ * // This would normally warn "type pattern is unchecked"
+ * // but here will blindly cast the head element to String.
+ * def g(xs: Any) = xs match { case x: List[String @unchecked] => x.head }
* }
- * }}}
- * will display the following warning:
- * {{{
- * test.scala:2: warning: does not cover case {object None}
- * def f(x: Option[int]) = x match {
- * ^
- * one warning found
- * }}}
- * The above message may be suppressed by substituting the expression `x`
- * with `(x: @unchecked)`. Then the modified code will compile silently,
- * but, in any case, a [[scala.MatchError]] will be raised at runtime.
+ * }}}
*
* @since 2.4
*/
diff --git a/src/reflect/scala/reflect/internal/TreeInfo.scala b/src/reflect/scala/reflect/internal/TreeInfo.scala
index 7ba749ed2c..dc05d221e6 100644
--- a/src/reflect/scala/reflect/internal/TreeInfo.scala
+++ b/src/reflect/scala/reflect/internal/TreeInfo.scala
@@ -326,9 +326,6 @@ abstract class TreeInfo {
case _ => false
}
- /** a Match(Typed(_, tpt), _) is unchecked if isUncheckedAnnotation(tpt.tpe) */
- def isUncheckedAnnotation(tpe: Type) = tpe hasAnnotation definitions.UncheckedClass
-
/** a Match(Typed(_, tpt), _) must be translated into a switch if isSwitchAnnotation(tpt.tpe) */
def isSwitchAnnotation(tpe: Type) = tpe hasAnnotation definitions.SwitchClass
diff --git a/test/files/neg/t3692-new.check b/test/files/neg/t3692-new.check
index 349e4fe48a..5aa991c105 100644
--- a/test/files/neg/t3692-new.check
+++ b/test/files/neg/t3692-new.check
@@ -1,4 +1,14 @@
-t3692-new.scala:16: error: unreachable code
- case m2: Map[T, Int] => new java.util.HashMap[T, Integer]
- ^
-one error found
+t3692-new.scala:14: warning: non-variable type argument Int in type pattern Map[Int,Int] is unchecked since it is eliminated by erasure
+ case m0: Map[Int, Int] => new java.util.HashMap[Integer, Integer]
+ ^
+t3692-new.scala:15: warning: non-variable type argument Int in type pattern Map[Int,V] is unchecked since it is eliminated by erasure
+ case m1: Map[Int, V] => new java.util.HashMap[Integer, V]
+ ^
+t3692-new.scala:16: warning: non-variable type argument Int in type pattern Map[T,Int] is unchecked since it is eliminated by erasure
+ case m2: Map[T, Int] => new java.util.HashMap[T, Integer]
+ ^
+t3692-new.scala:16: error: unreachable code
+ case m2: Map[T, Int] => new java.util.HashMap[T, Integer]
+ ^
+three warnings found
+one error found
diff --git a/test/files/neg/t3692-old.check b/test/files/neg/t3692-old.check
index 92d71f7e4e..950f82951c 100644
--- a/test/files/neg/t3692-old.check
+++ b/test/files/neg/t3692-old.check
@@ -1,11 +1,20 @@
-t3692-old.scala:11: warning: type Manifest in object Predef is deprecated: Use scala.reflect.ClassTag (to capture erasures) or scala.reflect.runtime.universe.TypeTag (to capture types) or both instead
- private final def toJavaMap[T, V](map: Map[T, V])(implicit m1: Manifest[T], m2: Manifest[V]): java.util.Map[_, _] = {
- ^
-t3692-old.scala:11: warning: type Manifest in object Predef is deprecated: Use scala.reflect.ClassTag (to capture erasures) or scala.reflect.runtime.universe.TypeTag (to capture types) or both instead
- private final def toJavaMap[T, V](map: Map[T, V])(implicit m1: Manifest[T], m2: Manifest[V]): java.util.Map[_, _] = {
- ^
-t3692-old.scala:15: error: unreachable code
- case m2: Map[T, Int] => new java.util.HashMap[T, Integer]
- ^
-two warnings found
-one error found
+t3692-old.scala:13: warning: non-variable type argument Int in type pattern Map[Int,Int] is unchecked since it is eliminated by erasure
+ case m0: Map[Int, Int] => new java.util.HashMap[Integer, Integer]
+ ^
+t3692-old.scala:14: warning: non-variable type argument Int in type pattern Map[Int,V] is unchecked since it is eliminated by erasure
+ case m1: Map[Int, V] => new java.util.HashMap[Integer, V]
+ ^
+t3692-old.scala:15: warning: non-variable type argument Int in type pattern Map[T,Int] is unchecked since it is eliminated by erasure
+ case m2: Map[T, Int] => new java.util.HashMap[T, Integer]
+ ^
+t3692-old.scala:11: warning: type Manifest in object Predef is deprecated: Use scala.reflect.ClassTag (to capture erasures) or scala.reflect.runtime.universe.TypeTag (to capture types) or both instead
+ private final def toJavaMap[T, V](map: Map[T, V])(implicit m1: Manifest[T], m2: Manifest[V]): java.util.Map[_, _] = {
+ ^
+t3692-old.scala:11: warning: type Manifest in object Predef is deprecated: Use scala.reflect.ClassTag (to capture erasures) or scala.reflect.runtime.universe.TypeTag (to capture types) or both instead
+ private final def toJavaMap[T, V](map: Map[T, V])(implicit m1: Manifest[T], m2: Manifest[V]): java.util.Map[_, _] = {
+ ^
+t3692-old.scala:15: error: unreachable code
+ case m2: Map[T, Int] => new java.util.HashMap[T, Integer]
+ ^
+5 warnings found
+one error found
diff --git a/test/files/neg/unchecked-suppress.check b/test/files/neg/unchecked-suppress.check
new file mode 100644
index 0000000000..2e23d21386
--- /dev/null
+++ b/test/files/neg/unchecked-suppress.check
@@ -0,0 +1,10 @@
+unchecked-suppress.scala:4: error: non-variable type argument Int in type pattern Set[Int] is unchecked since it is eliminated by erasure
+ case xs: Set[Int] => xs.head // unchecked
+ ^
+unchecked-suppress.scala:5: error: non-variable type argument String in type pattern Map[String @unchecked,String] is unchecked since it is eliminated by erasure
+ case xs: Map[String @unchecked, String] => xs.head // one unchecked, one okay
+ ^
+unchecked-suppress.scala:7: error: non-variable type argument Int in type pattern (Int, Int) => Int is unchecked since it is eliminated by erasure
+ case f: ((Int, Int) => Int) => // unchecked
+ ^
+three errors found
diff --git a/test/files/neg/unchecked-suppress.flags b/test/files/neg/unchecked-suppress.flags
new file mode 100644
index 0000000000..e8fb65d50c
--- /dev/null
+++ b/test/files/neg/unchecked-suppress.flags
@@ -0,0 +1 @@
+-Xfatal-warnings \ No newline at end of file
diff --git a/test/files/neg/unchecked-suppress.scala b/test/files/neg/unchecked-suppress.scala
new file mode 100644
index 0000000000..7bd61a2a4d
--- /dev/null
+++ b/test/files/neg/unchecked-suppress.scala
@@ -0,0 +1,10 @@
+class A {
+ def f(x: Any) = x match {
+ case xs: List[String @unchecked] => xs.head // okay
+ case xs: Set[Int] => xs.head // unchecked
+ case xs: Map[String @unchecked, String] => xs.head // one unchecked, one okay
+ case f: ((Int @unchecked) => (Int @unchecked)) => f(5) // okay
+ case f: ((Int, Int) => Int) => // unchecked
+ case _ => ""
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-15 04:52:45 +0000