Merge pull request scala#2930 from retronym/topic/patmat-inference-prep

Topic/patmat inference prep

Author: retronym

src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala

@@ -285,8 +285,8 @@ trait TypeDiagnostics {
           case xs   => xs map (_ => "_") mkString (clazz.name + "[", ",", "]")
         })+ "`"
 
-    "\nNote: if you intended to match against the class, try "+ caseString
-
+    if (!clazz.exists) ""
+    else "\nNote: if you intended to match against the class, try "+ caseString
   }
 
   case class TypeDiag(tp: Type, sym: Symbol) extends Ordered[TypeDiag] {

test/files/neg/bad-advice.check

@@ -0,0 +1,6 @@
+bad-advice.scala:4: error: pattern type is incompatible with expected type;
+ found   : Bip.type
+ required: Int
+    case Bip => true
+         ^
+one error found

test/files/neg/bad-advice.flags

@@ -0,0 +1 @@
+-Xfatal-warnings

test/files/neg/bad-advice.scala

@@ -0,0 +1,6 @@
+object Bip
+object Test {
+  def f(x: Int) = x match {
+    case Bip => true
+  }
+}

test/files/neg/macro-invalidret-nontree.check

@@ -6,6 +6,7 @@ declare quiet failed update partest_debug
 declare cotouched since sortCommand
 declare -a ack_args partest_args scalac_args
 
+partest_args=( --show-diff )
 base="$(cd "$(dirname "$0")"/.. && pwd)"
 cd "$base" || { echo "Could not change to base directory $base" && exit 1; }
 filesdir="test/files"
@@ -134,8 +135,8 @@ count=$(echo $(echo "$paths" | wc -w))
 
 # Output a command line which will re-run these same tests.
 echo "# $count tests to run."
-printf "%-52s %s\n" "$base/test/partest ${partest_args[@]}" "\\"
+printf "%-52s %s\n" "$base/test/partest ${partest_args[*]}" "\\"
 for path in $paths; do  printf "  %-50s %s\n" "$path" "\\"; done
-echo '  ""'
+echo ""
 
-test/partest "${partest_args[@]}" $paths
+test/partest ${partest_args[*]} $paths