Merge pull request #8292 from som-snytt/issue/xlint-help

More clarifying -Xlint:help

src/compiler/scala/tools/nsc/settings/Warnings.scala

@@ -91,29 +91,29 @@ trait Warnings {
     class LintWarning(name: String, help: String) extends Choice(name, help)
     def LintWarning(name: String, help: String) = new LintWarning(name, help)
 
-    val AdaptedArgs            = LintWarning("adapted-args",              "Warn if an argument list is modified to match the receiver.")
-    val NullaryUnit            = LintWarning("nullary-unit",              "Warn when nullary methods return Unit.")
+    val AdaptedArgs            = LintWarning("adapted-args",              "An argument list was modified to match the receiver.")
+    val NullaryUnit            = LintWarning("nullary-unit",              "`def f: Unit` looks like an accessor; add parens to look side-effecting.")
     val Inaccessible           = LintWarning("inaccessible",              "Warn about inaccessible types in method signatures.")
-    val NullaryOverride        = LintWarning("nullary-override",          "Warn when non-nullary `def f()' overrides nullary `def f'.")
-    val InferAny               = LintWarning("infer-any",                 "Warn when a type argument is inferred to be `Any`.")
+    val NullaryOverride        = LintWarning("nullary-override",          "Non-nullary `def f()` overrides nullary `def f`.")
+    val InferAny               = LintWarning("infer-any",                 "A type argument was inferred as Any.")
     val MissingInterpolator    = LintWarning("missing-interpolator",      "A string literal appears to be missing an interpolator id.")
-    val DocDetached            = LintWarning("doc-detached",              "A Scaladoc comment appears to be detached from its element.")
+    val DocDetached            = LintWarning("doc-detached",              "When running scaladoc, warn if a doc comment is discarded.")
     val PrivateShadow          = LintWarning("private-shadow",            "A private field (or class parameter) shadows a superclass field.")
     val TypeParameterShadow    = LintWarning("type-parameter-shadow",     "A local type parameter shadows a type already in scope.")
     val PolyImplicitOverload   = LintWarning("poly-implicit-overload",    "Parameterized overloaded implicit methods are not visible as view bounds.")
-    val OptionImplicit         = LintWarning("option-implicit",           "Option.apply used implicit view.")
+    val OptionImplicit         = LintWarning("option-implicit",           "Option.apply used an implicit view.")
     val DelayedInitSelect      = LintWarning("delayedinit-select",        "Selecting member of DelayedInit.")
     val PackageObjectClasses   = LintWarning("package-object-classes",    "Class or object defined in package object.")
-    val StarsAlign             = LintWarning("stars-align",               "Pattern sequence wildcard must align with sequence component.")
-    val Constant               = LintWarning("constant",                  "Evaluation of a constant arithmetic expression results in an error.")
+    val StarsAlign             = LintWarning("stars-align",               "In a pattern, a sequence wildcard `_*` should match all of a repeated parameter.")
+    val Constant               = LintWarning("constant",                  "Evaluation of a constant arithmetic expression resulted in an error.")
     val Unused                 = LintWarning("unused",                    "Enable -Wunused:imports,privates,locals,implicits.")
     val NonlocalReturn         = LintWarning("nonlocal-return",           "A return statement used an exception for flow control.")
     val ImplicitNotFound       = LintWarning("implicit-not-found",        "Check @implicitNotFound and @implicitAmbiguous messages.")
     val Serial                 = LintWarning("serial",                    "@SerialVersionUID on traits and non-serializable classes.")
     val ValPattern             = LintWarning("valpattern",                "Enable pattern checks in val definitions.")
-    val EtaZero                = LintWarning("eta-zero",                  "Warn on eta-expansion (rather than auto-application) of zero-ary method.")
-    val EtaSam                 = LintWarning("eta-sam",                   "Warn on eta-expansion to meet a Java-defined functional interface that is not explicitly annotated with @FunctionalInterface.")
-    val Deprecation            = LintWarning("deprecation",               "Enable linted deprecations.")
+    val EtaZero                = LintWarning("eta-zero",                  "Usage `f` of parameterless `def f()` resulted in eta-expansion, not empty application `f()`.")
+    val EtaSam                 = LintWarning("eta-sam",                   "The Java-defined target interface for eta-expansion was not annotated @FunctionalInterface.")
+    val Deprecation            = LintWarning("deprecation",               "Enable -deprecation and also check @deprecated annotations.")
 
     def allLintWarnings = values.toSeq.asInstanceOf[Seq[LintWarning]]
   }