SI-8667 Improve too-many-args message

Use removeNames to help diagnose the application.
Supplement the error message with how many extra
args and any other residual assignments that the
user might have thought was a properly named arg.

The error message is gradual: succinct for short
arg lists, more verbose for longer applications.
Very long arg lists are probably generated, so
that message is the least colloquial.

Author: som-snytt

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

@@ -538,8 +538,33 @@ trait ContextErrors {
       def NamedAndDefaultArgumentsNotSupportedForMacros(tree: Tree, fun: Tree) =
         NormalTypeError(tree, "macro applications do not support named and/or default arguments")
 
-      def TooManyArgsNamesDefaultsError(tree: Tree, fun: Tree) =
-        NormalTypeError(tree, "too many arguments for "+treeSymTypeMsg(fun))
+      def TooManyArgsNamesDefaultsError(tree: Tree, fun: Tree, expected: Int, supplied: Int, unknowns: List[Name]) = {
+        val msg = {
+          val badappl = {
+            val excess = supplied - expected
+            val target = treeSymTypeMsg(fun)
+
+            if (expected == 0) s"no arguments allowed for nullary $target"
+            else if (excess < 3 && expected <= 5) s"too many arguments ($supplied) for $target"
+            else if (expected > 10) s"$supplied arguments but expected $expected for $target"
+            else {
+              val oneOf =
+                if (excess == 1) "one more argument"
+                else if (excess > 0) s"$excess more arguments"
+                else "too many arguments"
+              s"$oneOf than can be applied to $target"
+            }
+          }
+          val suppl = 
+            unknowns.size match {
+              case 0 => ""
+              case 1 => s"\nNote that '${unknowns.head}' is not a parameter name of the invoked method."
+              case _ => unknowns.mkString("\nNote that '", "', '", "' are not parameter names of the invoked method.")
+            }
+          s"${badappl}${suppl}"
+        }
+        NormalTypeError(tree, msg)
+      }
 
       // can it still happen? see test case neg/overloaded-unapply.scala
       def OverloadedUnapplyError(tree: Tree) =
@@ -551,7 +576,7 @@ trait ContextErrors {
       def MultipleVarargError(tree: Tree) =
         NormalTypeError(tree, "when using named arguments, the vararg parameter has to be specified exactly once")
 
-      def ModuleUsingCompanionClassDefaultArgsErrror(tree: Tree) =
+      def ModuleUsingCompanionClassDefaultArgsError(tree: Tree) =
         NormalTypeError(tree, "module extending its companion class cannot use default constructor arguments")
 
       def NotEnoughArgsError(tree: Tree, fun: Tree, missing: List[Symbol]) = {

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

@@ -3330,7 +3330,13 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper
               // #2064
               duplErrorTree(WrongNumberOfArgsError(tree, fun))
             } else if (lencmp > 0) {
-              tryTupleApply orElse duplErrorTree(TooManyArgsNamesDefaultsError(tree, fun))
+              tryTupleApply orElse duplErrorTree {
+                val (namelessArgs, _) = removeNames(Typer.this)(args, params)
+                val wrongs = (namelessArgs zip args) collect {
+                  case (_: Assign, AssignOrNamedArg(Ident(name), _)) => name
+                }
+                TooManyArgsNamesDefaultsError(tree, fun, expected = formals.size, supplied = args.size, wrongs)
+              }
             } else if (lencmp == 0) {
               // we don't need defaults. names were used, so this application is transformed
               // into a block (@see transformNamedApplication in NamesDefaults)
@@ -3394,7 +3400,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper
                 val lencmp2 = compareLengths(allArgs, formals)
 
                 if (!sameLength(allArgs, args) && callToCompanionConstr(context, funSym)) {
-                  duplErrorTree(ModuleUsingCompanionClassDefaultArgsErrror(tree))
+                  duplErrorTree(ModuleUsingCompanionClassDefaultArgsError(tree))
                 } else if (lencmp2 > 0) {
                   removeNames(Typer.this)(allArgs, params) // #3818
                   duplErrTree

test/files/neg/eta-expand-star.check

@@ -1,4 +1,4 @@
-eta-expand-star.scala:6: error: too many arguments for method apply: (v1: Seq[T])Unit in trait Function1
+eta-expand-star.scala:6: error: too many arguments (2) for method apply: (v1: Seq[T])Unit in trait Function1
     g(1, 2)
      ^
 one error found

test/files/neg/macro-invalidusage-badargs.check

@@ -13,7 +13,7 @@ Macros_Test_2.scala:8: error: not enough arguments for macro method foo: (x: Int
 Unspecified value parameter x.
   foo()
      ^
-Macros_Test_2.scala:9: error: too many arguments for macro method foo: (x: Int)Int
+Macros_Test_2.scala:9: error: too many arguments (2) for macro method foo: (x: Int)Int
   foo(4, 2)
      ^
 5 errors found

test/files/neg/multi-array.check

@@ -1,4 +1,4 @@
-multi-array.scala:7: error: too many arguments for constructor Array: (_length: Int)Array[T]
+multi-array.scala:7: error: too many arguments (2) for constructor Array: (_length: Int)Array[T]
   val a: Array[Int] = new Array(10, 10)
                       ^
 one error found

test/files/neg/protected-constructors.check

@@ -1,4 +1,4 @@
-protected-constructors.scala:17: error: too many arguments for constructor Foo1: ()dingus.Foo1
+protected-constructors.scala:17: error: no arguments allowed for nullary constructor Foo1: ()dingus.Foo1
     val foo1 = new Foo1("abc")
                ^
 protected-constructors.scala:18: error: constructor Foo2 in class Foo2 cannot be accessed in object P

test/files/neg/t1112.check

@@ -1,4 +1,4 @@
-t1112.scala:12: error: too many arguments for method call: (p: Int)(f: => Test.this.Type1)Unit
+t1112.scala:12: error: too many arguments (2) for method call: (p: Int)(f: => Test.this.Type1)Unit
     call(0,() => System.out.println("here we are"))
         ^
 one error found

test/files/neg/t1523.check

@@ -1,4 +1,4 @@
-t1523.scala:4: error: too many arguments for method bug: (x: Any)Any
+t1523.scala:4: error: 25 more arguments than can be applied to method bug: (x: Any)Any
   def go() = bug("a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "a")
                 ^
 one error found

test/files/neg/t6920.check

@@ -1,4 +1,4 @@
-t6920.scala:9: error: too many arguments for method applyDynamicNamed: (values: Seq[(String, Any)])String
+t6920.scala:9: error: too many arguments (2) for method applyDynamicNamed: (values: Seq[(String, Any)])String
 error after rewriting to CompilerError.this.test.applyDynamicNamed("crushTheCompiler")(scala.Tuple2("a", 1), scala.Tuple2("b", 2))
 possible cause: maybe a wrong Dynamic method signature?
   test.crushTheCompiler(a = 1, b = 2)

test/files/neg/t7157.check

@@ -1,20 +1,20 @@
-Test_2.scala:5: error: too many arguments for macro method m1_0_0: ()Unit
+Test_2.scala:5: error: no arguments allowed for nullary macro method m1_0_0: ()Unit
   m1_0_0(1)
         ^
-Test_2.scala:6: error: too many arguments for macro method m1_0_0: ()Unit
+Test_2.scala:6: error: no arguments allowed for nullary macro method m1_0_0: ()Unit
   m1_0_0(1, 2)
         ^
-Test_2.scala:7: error: too many arguments for macro method m1_0_0: ()Unit
+Test_2.scala:7: error: no arguments allowed for nullary macro method m1_0_0: ()Unit
   m1_0_0(1, 2, 3)
         ^
 Test_2.scala:9: error: not enough arguments for macro method m1_1_1: (x: Int)Unit.
 Unspecified value parameter x.
   m1_1_1()
         ^
-Test_2.scala:11: error: too many arguments for macro method m1_1_1: (x: Int)Unit
+Test_2.scala:11: error: too many arguments (2) for macro method m1_1_1: (x: Int)Unit
   m1_1_1(1, 2)
         ^
-Test_2.scala:12: error: too many arguments for macro method m1_1_1: (x: Int)Unit
+Test_2.scala:12: error: too many arguments (3) for macro method m1_1_1: (x: Int)Unit
   m1_1_1(1, 2, 3)
         ^
 Test_2.scala:14: error: not enough arguments for macro method m1_2_2: (x: Int, y: Int)Unit.
@@ -25,7 +25,7 @@ Test_2.scala:15: error: not enough arguments for macro method m1_2_2: (x: Int, y
 Unspecified value parameter y.
   m1_2_2(1)
         ^
-Test_2.scala:17: error: too many arguments for macro method m1_2_2: (x: Int, y: Int)Unit
+Test_2.scala:17: error: too many arguments (3) for macro method m1_2_2: (x: Int, y: Int)Unit
   m1_2_2(1, 2, 3)
         ^
 Test_2.scala:24: error: not enough arguments for macro method m1_1_inf: (x: Int, y: Int*)Unit.
@@ -40,23 +40,23 @@ Test_2.scala:30: error: not enough arguments for macro method m1_2_inf: (x: Int,
 Unspecified value parameters y, z.
   m1_2_inf(1)
           ^
-Test_2.scala:35: error: too many arguments for macro method m2_0_0: ()Unit
+Test_2.scala:35: error: no arguments allowed for nullary macro method m2_0_0: ()Unit
   m2_0_0()(1)
           ^
-Test_2.scala:36: error: too many arguments for macro method m2_0_0: ()Unit
+Test_2.scala:36: error: no arguments allowed for nullary macro method m2_0_0: ()Unit
   m2_0_0()(1, 2)
           ^
-Test_2.scala:37: error: too many arguments for macro method m2_0_0: ()Unit
+Test_2.scala:37: error: no arguments allowed for nullary macro method m2_0_0: ()Unit
   m2_0_0()(1, 2, 3)
           ^
 Test_2.scala:39: error: not enough arguments for macro method m2_1_1: (x: Int)Unit.
 Unspecified value parameter x.
   m2_1_1()()
           ^
-Test_2.scala:41: error: too many arguments for macro method m2_1_1: (x: Int)Unit
+Test_2.scala:41: error: too many arguments (2) for macro method m2_1_1: (x: Int)Unit
   m2_1_1()(1, 2)
           ^
-Test_2.scala:42: error: too many arguments for macro method m2_1_1: (x: Int)Unit
+Test_2.scala:42: error: too many arguments (3) for macro method m2_1_1: (x: Int)Unit
   m2_1_1()(1, 2, 3)
           ^
 Test_2.scala:44: error: not enough arguments for macro method m2_2_2: (x: Int, y: Int)Unit.
@@ -67,7 +67,7 @@ Test_2.scala:45: error: not enough arguments for macro method m2_2_2: (x: Int, y
 Unspecified value parameter y.
   m2_2_2()(1)
           ^
-Test_2.scala:47: error: too many arguments for macro method m2_2_2: (x: Int, y: Int)Unit
+Test_2.scala:47: error: too many arguments (3) for macro method m2_2_2: (x: Int, y: Int)Unit
   m2_2_2()(1, 2, 3)
           ^
 Test_2.scala:54: error: not enough arguments for macro method m2_1_inf: (x: Int, y: Int*)Unit.

test/files/neg/t8006.check

@@ -1,4 +1,4 @@
-t8006.scala:3: error: too many arguments for method applyDynamicNamed: (value: (String, Any))String
+t8006.scala:3: error: too many arguments (2) for method applyDynamicNamed: (value: (String, Any))String
 error after rewriting to X.this.d.applyDynamicNamed("meth")(scala.Tuple2("value1", 10), scala.Tuple2("value2", 100))
 possible cause: maybe a wrong Dynamic method signature?
   d.meth(value1 = 10, value2 = 100) // two arguments here, but only one is allowed

test/files/neg/t8035-no-adapted-args.check

@@ -4,7 +4,7 @@ t8035-no-adapted-args.scala:4: warning: No automatic adaptation here: use explic
  after adaptation: Test.f((1, 2, 3): (Int, Int, Int))
   f(1, 2, 3)
    ^
-t8035-no-adapted-args.scala:4: error: too many arguments for method f: (x: (Int, Int, Int))Int
+t8035-no-adapted-args.scala:4: error: too many arguments (3) for method f: (x: (Int, Int, Int))Int
   f(1, 2, 3)
    ^
 t8035-no-adapted-args.scala:5: warning: No automatic adaptation here: use explicit parentheses.

test/files/neg/t8667.check

@@ -0,0 +1,79 @@
+t8667.scala:6: error: too many arguments (3) for constructor C: (a: Int, b: Int)C
+Note that 'c' is not a parameter name of the invoked method.
+  def c2 = new C(a = 42, b = 17, c = 5)
+           ^
+t8667.scala:7: error: unknown parameter name: c
+  def c3 = new C(b = 42, a = 17, c = 5)
+                                   ^
+t8667.scala:7: error: too many arguments (3) for constructor C: (a: Int, b: Int)C
+  def c3 = new C(b = 42, a = 17, c = 5)
+           ^
+t8667.scala:8: error: positional after named argument.
+  def c4 = new C(b = 42, a = 17, 5)
+                                 ^
+t8667.scala:8: error: too many arguments (3) for constructor C: (a: Int, b: Int)C
+  def c4 = new C(b = 42, a = 17, 5)
+           ^
+t8667.scala:9: error: not found: value c
+  def c5 = new C(a = 42, c = 17)
+                         ^
+t8667.scala:10: error: parameter 'b' is already specified at parameter position 2
+Note that 'c' is not a parameter name of the invoked method.
+  def c6 = new C(a = 42, c = 17, b = 5)
+                                   ^
+t8667.scala:10: error: too many arguments (3) for constructor C: (a: Int, b: Int)C
+Note that 'c' is not a parameter name of the invoked method.
+  def c6 = new C(a = 42, c = 17, b = 5)
+           ^
+t8667.scala:11: error: too many arguments (3) for constructor C: (a: Int, b: Int)C
+Note that 'c' is not a parameter name of the invoked method.
+  def c7 = new C(42, 17, c = 5)
+           ^
+t8667.scala:12: error: parameter 'b' is already specified at parameter position 2
+  def c8 = new C(42, 17, b = 5)
+                           ^
+t8667.scala:12: error: too many arguments (3) for constructor C: (a: Int, b: Int)C
+  def c8 = new C(42, 17, b = 5)
+           ^
+t8667.scala:13: error: parameter 'b' is already specified at parameter position 2
+Note that 'c' is not a parameter name of the invoked method.
+  def c9 = new C(a = 42, c = 17, d = 3, b = 5)
+                                          ^
+t8667.scala:13: error: too many arguments (4) for constructor C: (a: Int, b: Int)C
+Note that 'c', 'd' are not parameter names of the invoked method.
+  def c9 = new C(a = 42, c = 17, d = 3, b = 5)
+           ^
+t8667.scala:14: error: too many arguments (4) for constructor C: (a: Int, b: Int)C
+Note that 'd', 'c' are not parameter names of the invoked method.
+  def c0 = new C(42, 17, d = 3, c = 5)
+           ^
+t8667.scala:24: error: no arguments allowed for nullary method f0: ()Int
+    f0(1)
+      ^
+t8667.scala:25: error: too many arguments (2) for method f1: (i: Int)Int
+    f1(1, 2)
+      ^
+t8667.scala:26: error: too many arguments (3) for method f1: (i: Int)Int
+    f1(1, 2, 3)
+      ^
+t8667.scala:27: error: 3 more arguments than can be applied to method f1: (i: Int)Int
+    f1(1, 2, 3, 4)
+      ^
+t8667.scala:28: error: 3 more arguments than can be applied to method f1: (i: Int)Int
+Note that 'j' is not a parameter name of the invoked method.
+    f1(1, j = 2, 3, 4)
+      ^
+t8667.scala:29: error: 3 more arguments than can be applied to method f1: (i: Int)Int
+Note that 'j', 'k' are not parameter names of the invoked method.
+    f1(1, j = 2, k = 3, 4)
+      ^
+t8667.scala:30: error: one more argument than can be applied to method f6: (i: Int, j: Int, k: Int, l: Int, m: Int, n: Int)Int
+    f6(1, 2, 3, 4, 5, 6, 7)
+      ^
+t8667.scala:31: error: 2 more arguments than can be applied to method f6: (i: Int, j: Int, k: Int, l: Int, m: Int, n: Int)Int
+    f6(1, 2, 3, 4, 5, 6, 7, 8)
+      ^
+t8667.scala:32: error: 15 arguments but expected 12 for method f12: (i: Int, j: Int, k: Int, l: Int, m: Int, n: Int, o: Int, p: Int, q: Int, r: Int, s: Int, t: Int)Int
+    f12(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
+       ^
+23 errors found

test/files/neg/t8667.scala

@@ -0,0 +1,35 @@
+
+class C(a: Int, b: Int)
+
+trait T {
+  def c1 = new C(a = 42, b = 17)
+  def c2 = new C(a = 42, b = 17, c = 5)
+  def c3 = new C(b = 42, a = 17, c = 5)
+  def c4 = new C(b = 42, a = 17, 5)
+  def c5 = new C(a = 42, c = 17)
+  def c6 = new C(a = 42, c = 17, b = 5)
+  def c7 = new C(42, 17, c = 5)
+  def c8 = new C(42, 17, b = 5)
+  def c9 = new C(a = 42, c = 17, d = 3, b = 5)
+  def c0 = new C(42, 17, d = 3, c = 5)
+}
+
+trait X {
+  def f0() = 42
+  def f1(i: Int) = 42
+  def f6(i: Int, j: Int, k: Int, l: Int, m: Int, n: Int) = 42
+  def f12(i: Int, j: Int, k: Int, l: Int, m: Int, n: Int, o: Int, p: Int, q: Int, r: Int, s: Int, t: Int) = 42
+
+  def g() = {
+    f0(1)
+    f1(1, 2)
+    f1(1, 2, 3)
+    f1(1, 2, 3, 4)
+    f1(1, j = 2, 3, 4)
+    f1(1, j = 2, k = 3, 4)
+    f6(1, 2, 3, 4, 5, 6, 7)
+    f6(1, 2, 3, 4, 5, 6, 7, 8)
+    f12(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
+    ()
+  }
+}

test/files/neg/t876.check

@@ -1,4 +1,4 @@
-t876.scala:25: error: too many arguments for method apply: (key: AssertionError.A)manager.B in class HashMap
+t876.scala:25: error: too many arguments (2) for method apply: (key: AssertionError.A)manager.B in class HashMap
         assert(manager.map(A2) == List(manager.map(A2, A1)))
                                                   ^
 one error found