Merge pull request #1228 from retronym/ticket/4270-xlogimplicits

More useful -Xlog-implicits output.

4 files changed, 29 insertions, 4 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
index 226e17f605..6a91922b4c 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
@@ -593,7 +593,7 @@ trait Implicits {
             typed1(itree, EXPRmode, wildPt)
 
         if (context.hasErrors)
-          return fail("typed implicit %s has errors".format(info.sym.fullLocationString))
+          return fail(context.errBuffer.head.errMsg)
 
         if (Statistics.canEnable) Statistics.incCounter(typedImplicits)
 
@@ -615,7 +615,7 @@ trait Implicits {
         }
 
         if (context.hasErrors)
-          fail("hasMatchingSymbol reported threw error(s)")
+          fail("hasMatchingSymbol reported error: " + context.errBuffer.head.errMsg)
         else if (isLocal && !hasMatchingSymbol(itree1))
           fail("candidate implicit %s is shadowed by %s".format(
             info.sym.fullLocationString, itree1.symbol.fullLocationString))
@@ -639,7 +639,7 @@ trait Implicits {
             // #2421: check that we correctly instantiated type parameters outside of the implicit tree:
             checkBounds(itree2, NoPrefix, NoSymbol, undetParams, targs, "inferred ")
             if (context.hasErrors)
-              return fail("type parameters weren't correctly instantiated outside of the implicit tree")
+              return fail("type parameters weren't correctly instantiated outside of the implicit tree: " + context.errBuffer.head.errMsg)
 
             // filter out failures from type inference, don't want to remove them from undetParams!
             // we must be conservative in leaving type params in undetparams
@@ -675,7 +675,7 @@ trait Implicits {
             }
 
             if (context.hasErrors)
-              fail("typing TypeApply reported errors for the implicit tree")
+              fail("typing TypeApply reported errors for the implicit tree: " + context.errBuffer.head.errMsg)
             else {
               val result = new SearchResult(itree2, subst)
               if (Statistics.canEnable) Statistics.incCounter(foundImplicits)
diff --git a/test/files/neg/implicit-shadow.check b/test/files/neg/implicit-shadow.check
new file mode 100644
index 0000000000..042fca867a
--- /dev/null
+++ b/test/files/neg/implicit-shadow.check
@@ -0,0 +1,11 @@
+implicit-shadow.scala:4: <i2s: error> is not a valid implicit value for Int(1) => ?{def isEmpty: ?} because:
+reference to i2s is ambiguous;
+it is imported twice in the same scope by
+import C._
+and import B._
+	1.isEmpty
+        ^
+implicit-shadow.scala:4: error: value isEmpty is not a member of Int
+	1.isEmpty
+          ^
+one error found
diff --git a/test/files/neg/implicit-shadow.flags b/test/files/neg/implicit-shadow.flags
new file mode 100644
index 0000000000..44842a9d65
--- /dev/null
+++ b/test/files/neg/implicit-shadow.flags
@@ -0,0 +1 @@
+-Xlog-implicits
diff --git a/test/files/neg/implicit-shadow.scala b/test/files/neg/implicit-shadow.scala
new file mode 100644
index 0000000000..ffd34b6408
--- /dev/null
+++ b/test/files/neg/implicit-shadow.scala
@@ -0,0 +1,13 @@
+object Test {
+	import B._, C._
+
+	1.isEmpty
+}
+
+trait A {
+	implicit def i2s(i: Int): String = ""
+}
+
+object B extends A
+
+object C extends A
\ No newline at end of file