Rely less on intricacies of `contextMode`-based reporting.

 - when warning must not be suppressed, use `reporter.warning`
 - don't (implicitly) rely on `reporter.warning` being silent after typer
   --> don't do pure expression check after typer

3 files changed, 6 insertions, 6 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
index 6951ff2f0b..1010ceafe3 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
@@ -640,8 +640,8 @@ trait Contexts { self: Analyzer =>
     }
 
     /** Issue/throw the given error message according to the current mode for error reporting. */
-    def warning(pos: Position, msg: String, force: Boolean = false) {
-      if (reportErrors || force) reporter.warning(pos, msg)
+    def warning(pos: Position, msg: String) {
+      if (reportErrors) reporter.warning(pos, msg)
       else if (bufferErrors) reportBuffer += (pos -> msg)
     }
 
diff --git a/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala b/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala
index 7440f69e93..fbea69db5a 100644
--- a/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala
@@ -572,11 +572,11 @@ trait TypeDiagnostics {
         } else f
       }
       def apply(tree: Tree): Tree = {
-        // Error suppression will squash some of these warnings unless we circumvent it.
+        // Error suppression (in context.warning) would squash some of these warnings.
         // It is presumed if you are using a -Y option you would really like to hear
-        // the warnings you've requested.
+        // the warnings you've requested; thus, use reporter.warning.
         if (settings.warnDeadCode && context.unit.exists && treeOK(tree) && exprOK)
-          context.warning(tree.pos, "dead code following this construct", force = true)
+          reporter.warning(tree.pos, "dead code following this construct")
         tree
       }
 
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index e0af229d3a..ce031e9cd7 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -2990,7 +2990,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper
                     ConstructorsOrderError(stat)
                 }
 
-                if (treeInfo.isPureExprForWarningPurposes(result)) context.warning(stat.pos,
+                if (!isPastTyper && treeInfo.isPureExprForWarningPurposes(result)) context.warning(stat.pos,
                   "a pure expression does nothing in statement position; " +
                   "you may be omitting necessary parentheses"
                 )