SI-9045 Error on recursive ctor

If the constructor invokes itself, say so.

7 files changed, 32 insertions, 11 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
index ccdff5c9a1..e190b57017 100644
--- a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
@@ -469,6 +469,11 @@ trait ContextErrors {
         setError(tree)
       }
 
+      def ConstructorRecursesError(tree: Tree) = {
+        issueNormalTypeError(tree, "constructor invokes itself")
+        setError(tree)
+      }
+
       def OnlyDeclarationsError(tree: Tree) = {
         issueNormalTypeError(tree, "only declarations allowed here")
         setError(tree)
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 65c6e09fd3..329ce8c23b 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -3003,22 +3003,23 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper
         // skip typechecking of statements in a sequence where some other statement includes the targetposition
         case s if localTarget && !includesTargetPos(s) => s
         case _ =>
-          val localTyper = if (inBlock || (stat.isDef && !stat.isInstanceOf[LabelDef])) {
-            this
-          } else newTyper(context.make(stat, exprOwner))
+          val localTyper = if (inBlock || (stat.isDef && !stat.isInstanceOf[LabelDef])) this
+                           else newTyper(context.make(stat, exprOwner))
           // XXX this creates a spurious dead code warning if an exception is thrown
           // in a constructor, even if it is the only thing in the constructor.
           val result = checkDead(localTyper.typedByValueExpr(stat))
 
           if (treeInfo.isSelfOrSuperConstrCall(result)) {
             context.inConstructorSuffix = true
-            if (treeInfo.isSelfConstrCall(result) && result.symbol.pos.pointOrElse(0) >= exprOwner.enclMethod.pos.pointOrElse(0))
-              ConstructorsOrderError(stat)
+            if (treeInfo.isSelfConstrCall(result)) {
+              if (result.symbol == exprOwner.enclMethod)
+                ConstructorRecursesError(stat)
+              else if (result.symbol.pos.pointOrElse(0) >= exprOwner.enclMethod.pos.pointOrElse(0))
+                ConstructorsOrderError(stat)
+            }
           }
-
           if (!isPastTyper && treeInfo.isPureExprForWarningPurposes(result)) context.warning(stat.pos,
-            "a pure expression does nothing in statement position; " +
-            "you may be omitting necessary parentheses"
+            "a pure expression does nothing in statement position; you may be omitting necessary parentheses"
           )
           result
       }
diff --git a/test/files/neg/constrs.check b/test/files/neg/constrs.check
index 4f4a12bc13..8a5bd97ae3 100644
--- a/test/files/neg/constrs.check
+++ b/test/files/neg/constrs.check
@@ -7,7 +7,7 @@ constrs.scala:6: error: value u is not a member of object test
 constrs.scala:10: error: called constructor's definition must precede calling constructor's definition
     def this() = this("abc")
                  ^
-constrs.scala:12: error: called constructor's definition must precede calling constructor's definition
+constrs.scala:12: error: constructor invokes itself
     def this(x: Boolean) = this(x)
                            ^
 constrs.scala:16: error: type mismatch;
diff --git a/test/files/neg/t4460a.check b/test/files/neg/t4460a.check
index b711e7acb1..7a7618a114 100644
--- a/test/files/neg/t4460a.check
+++ b/test/files/neg/t4460a.check
@@ -1,4 +1,4 @@
-t4460a.scala:6: error: called constructor's definition must precede calling constructor's definition
+t4460a.scala:6: error: constructor invokes itself
   def this() = this() // was binding to Predef.<init> !!
                ^
 one error found
diff --git a/test/files/neg/t4460b.check b/test/files/neg/t4460b.check
index f0e703fd10..9a621dbd5c 100644
--- a/test/files/neg/t4460b.check
+++ b/test/files/neg/t4460b.check
@@ -1,4 +1,4 @@
-t4460b.scala:7: error: called constructor's definition must precede calling constructor's definition
+t4460b.scala:7: error: constructor invokes itself
 	  def this() = this() // was binding to Predef.<init> !!
                        ^
 one error found
diff --git a/test/files/neg/t9045.check b/test/files/neg/t9045.check
new file mode 100644
index 0000000000..07d0e2dd74
--- /dev/null
+++ b/test/files/neg/t9045.check
@@ -0,0 +1,7 @@
+t9045.scala:3: error: constructor invokes itself
+  def this(axes: Array[Int]) = this(axes)
+                               ^
+t9045.scala:6: error: called constructor's definition must precede calling constructor's definition
+  def this(d: Double) = this(d.toLong)
+                        ^
+two errors found
diff --git a/test/files/neg/t9045.scala b/test/files/neg/t9045.scala
new file mode 100644
index 0000000000..e6710ab324
--- /dev/null
+++ b/test/files/neg/t9045.scala
@@ -0,0 +1,8 @@
+
+case class AffineImageShape(axes: Seq[Int]) {
+  def this(axes: Array[Int]) = this(axes)
+}
+class X(i: Int) {
+  def this(d: Double) = this(d.toLong)
+  def this(n: Long) = this(n.toInt)
+}