Improve mismatched arg list message for tupling

Nameless args are caught early

Since 2.13, named args with a bad name error early.
When concocting messages for arity mismatches, there
is no longer any need to consider badly named args.

Author: som-snytt

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

@@ -605,7 +605,7 @@ 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, formals: List[Type], args: List[Tree], namelessArgs: List[Tree], argPos: Array[Int]) = {
+      def TooManyArgsNamesDefaultsError(tree: Tree, fun: Tree, formals: List[Type], args: List[Tree], argPos: Array[Int]) = {
         val expected = formals.size
         val supplied = args.size
         // pick a caret. For f(k=1,i=2,j=3), argPos[0,-1,1] b/c `k=1` taken as arg0
@@ -614,27 +614,20 @@ trait ContextErrors {
           if (i < 0) tree else args(i min (supplied - 1))
         }
         val msg = {
-          val badappl = {
-            val excess = supplied - expected
-            val target = treeSymTypeMsg(fun)
-
-            if (expected == 0) args match {
-              case (c @ Literal(Constant(()))) :: Nil if c.hasAttachment[SyntheticUnitAttachment.type] =>
-                s"can't supply unit value with infix notation because nullary $target takes no arguments; use dotted invocation instead: ${show(treeCopy.Apply(tree, fun, Nil))}"
-              case _ => s"no arguments allowed for nullary $target"
-            } else
-              s"too many arguments ($supplied, expected $expected) for $target"
-          }
-          val unknowns = (namelessArgs zip args) collect {
-            case (_: Assign, NamedArg(Ident(name), _)) => name
+          val target = treeSymTypeMsg(fun)
+          def isAutoTuplable = AnyRefTpe <:< (if (formals.head.typeSymbol.isTypeParameter) formals.head.upperBound else formals.head)
+
+          expected match {
+            case 0 =>
+              args match {
+                case (c @ Literal(Constant(()))) :: Nil if c.hasAttachment[SyntheticUnitAttachment.type] =>
+                  s"can't supply unit value with infix notation because nullary $target takes no arguments; use dotted invocation instead: ${show(treeCopy.Apply(tree, fun, Nil))}"
+                case _ => s"no arguments allowed for nullary $target"
+              }
+            case 1 if isTupleType(formals.head) => s"too many arguments (found $supplied, expected ${formals.head.typeArgs.size}-tuple) for $target"
+            case 1 if supplied > MaxTupleArity && isAutoTuplable => s"too many arguments (found $supplied, which exceeds the largest Tuple) for $target"
+            case _ => s"too many arguments (found $supplied, expected $expected) for $target"
           }
-          val suppl =
-            unknowns.size match {
-              case 0 => ""
-              case 1 => s"\nNote that '${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(excessive, msg)
       }

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

@@ -3694,8 +3694,8 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper
               duplErrorTree(WrongNumberOfArgsError(tree, fun))
             } else if (lencmp > 0) {
               tryTupleApply orElse duplErrorTree {
-                val (namelessArgs, argPos) = removeNames(Typer.this)(args, params)
-                TooManyArgsNamesDefaultsError(tree, fun, formals, args, namelessArgs, argPos)
+                val (_, argPos) = removeNames(Typer.this)(args, params)
+                TooManyArgsNamesDefaultsError(tree, fun, formals, args, argPos)
               }
             } else if (lencmp == 0) {
               // we don't need defaults. names were used, so this application is transformed

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

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

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

@@ -13,7 +13,7 @@ Macros_Test_2.scala:9: error: not enough arguments for macro method foo: (x: Int
 Unspecified value parameter x.
   foo()
      ^
-Macros_Test_2.scala:10: error: too many arguments (2, expected 1) for macro method foo: (x: Int): Int
+Macros_Test_2.scala:10: error: too many arguments (found 2, expected 1) for macro method foo: (x: Int): Int
   foo(4, 2)
          ^
 5 errors

test/files/neg/multi-array.check

@@ -1,4 +1,4 @@
-multi-array.scala:9: error: too many arguments (2, expected 1) for constructor Array: (_length: Int): Array[T]
+multi-array.scala:9: error: too many arguments (found 2, expected 1) for constructor Array: (_length: Int): Array[T]
   val a: Array[Int] = new Array(10, 10)
                                     ^
 1 error

test/files/neg/t10207.check

@@ -1,4 +1,4 @@
-t10207.scala:14: error: too many arguments (2, expected 1) for method apply: (key: Int): scala.collection.mutable.ArrayBuffer[String] in trait MapOps
+t10207.scala:14: error: too many arguments (found 2, expected 1) for method apply: (key: Int): scala.collection.mutable.ArrayBuffer[String] in trait MapOps
   m(1, (_ => empty)) ++= AB("eins", "uno")
           ^
 1 error

test/files/neg/t1112.check

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

test/files/neg/t1523.check

@@ -1,4 +1,4 @@
-t1523.scala:4: error: too many arguments (26, expected 1) for method bug: (x: Any): Any
+t1523.scala:4: error: too many arguments (found 26, which exceeds the largest Tuple) for 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")
                       ^
 1 error

test/files/neg/t6920.check

@@ -1,4 +1,4 @@
-t6920.scala:9: error: too many arguments (2, expected 1) for method applyDynamicNamed: (values: Seq[(String, Any)]): String
+t6920.scala:9: error: too many arguments (found 2, expected 1) 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

@@ -11,10 +11,10 @@ Test_2.scala:9: error: not enough arguments for macro method m1_1_1: (x: Int): U
 Unspecified value parameter x.
   m1_1_1()
         ^
-Test_2.scala:11: error: too many arguments (2, expected 1) for macro method m1_1_1: (x: Int): Unit
+Test_2.scala:11: error: too many arguments (found 2, expected 1) for macro method m1_1_1: (x: Int): Unit
   m1_1_1(1, 2)
             ^
-Test_2.scala:12: error: too many arguments (3, expected 1) for macro method m1_1_1: (x: Int): Unit
+Test_2.scala:12: error: too many arguments (found 3, expected 1) 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 (3, expected 2) for macro method m1_2_2: (x: Int, y: Int): Unit
+Test_2.scala:17: error: too many arguments (found 3, expected 2) 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.
@@ -53,10 +53,10 @@ Test_2.scala:39: error: not enough arguments for macro method m2_1_1: (x: Int):
 Unspecified value parameter x.
   m2_1_1()()
           ^
-Test_2.scala:41: error: too many arguments (2, expected 1) for macro method m2_1_1: (x: Int): Unit
+Test_2.scala:41: error: too many arguments (found 2, expected 1) for macro method m2_1_1: (x: Int): Unit
   m2_1_1()(1, 2)
               ^
-Test_2.scala:42: error: too many arguments (3, expected 1) for macro method m2_1_1: (x: Int): Unit
+Test_2.scala:42: error: too many arguments (found 3, expected 1) 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 (3, expected 2) for macro method m2_2_2: (x: Int, y: Int): Unit
+Test_2.scala:47: error: too many arguments (found 3, expected 2) 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 (2, expected 1) for method applyDynamicNamed: (value: (String, Any)): String
+t8006.scala:3: error: too many arguments (found 2, expected 2-tuple) 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/t8667.check

@@ -1,19 +1,19 @@
 t8667.scala:6: error: unknown parameter name: c
   def c2 = new C(a = 42, b = 17, c = 5)
                                    ^
-t8667.scala:6: error: too many arguments (3, expected 2) for constructor C: (a: Int, b: Int): C
+t8667.scala:6: error: too many arguments (found 3, expected 2) for constructor C: (a: Int, b: Int): C
   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, expected 2) for constructor C: (a: Int, b: Int): C
+t8667.scala:7: error: too many arguments (found 3, expected 2) 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, expected 2) for constructor C: (a: Int, b: Int): C
+t8667.scala:8: error: too many arguments (found 3, expected 2) for constructor C: (a: Int, b: Int): C
   def c4 = new C(b = 42, a = 17, 5)
            ^
 t8667.scala:9: error: unknown parameter name: c
@@ -22,19 +22,19 @@ t8667.scala:9: error: unknown parameter name: c
 t8667.scala:10: error: unknown parameter name: c
   def c6 = new C(a = 42, c = 17, b = 5)
                            ^
-t8667.scala:10: error: too many arguments (3, expected 2) for constructor C: (a: Int, b: Int): C
+t8667.scala:10: error: too many arguments (found 3, expected 2) for constructor C: (a: Int, b: Int): C
   def c6 = new C(a = 42, c = 17, b = 5)
            ^
 t8667.scala:11: error: unknown parameter name: c
   def c7 = new C(c = 42, a = 17, b = 5)
                    ^
-t8667.scala:11: error: too many arguments (3, expected 2) for constructor C: (a: Int, b: Int): C
+t8667.scala:11: error: too many arguments (found 3, expected 2) for constructor C: (a: Int, b: Int): C
   def c7 = new C(c = 42, a = 17, b = 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, expected 2) for constructor C: (a: Int, b: Int): C
+t8667.scala:12: error: too many arguments (found 3, expected 2) for constructor C: (a: Int, b: Int): C
   def c8 = new C(42, 17, b = 5)
            ^
 t8667.scala:13: error: unknown parameter name: c
@@ -43,7 +43,7 @@ t8667.scala:13: error: unknown parameter name: c
 t8667.scala:13: error: unknown parameter name: d
   def c9 = new C(a = 42, c = 17, d = 3, b = 5)
                                    ^
-t8667.scala:13: error: too many arguments (4, expected 2) for constructor C: (a: Int, b: Int): C
+t8667.scala:13: error: too many arguments (found 4, expected 2) for constructor C: (a: Int, b: Int): C
   def c9 = new C(a = 42, c = 17, d = 3, b = 5)
            ^
 t8667.scala:14: error: unknown parameter name: d
@@ -52,55 +52,79 @@ t8667.scala:14: error: unknown parameter name: d
 t8667.scala:14: error: unknown parameter name: c
   def c0 = new C(42, 17, d = 3, c = 5)
                                   ^
-t8667.scala:14: error: too many arguments (4, expected 2) for constructor C: (a: Int, b: Int): C
+t8667.scala:14: error: too many arguments (found 4, expected 2) for constructor C: (a: Int, b: Int): C
   def c0 = new C(42, 17, d = 3, c = 5)
            ^
-t8667.scala:25: error: no arguments allowed for nullary method f0: (): Int
+t8667.scala:31: error: no arguments allowed for nullary method f0: (): Int
     f0(1)
        ^
-t8667.scala:26: error: too many arguments (2, expected 1) for method f1: (i: Int): Int
+t8667.scala:32: error: too many arguments (found 2, expected 1) for method f1: (i: Int): Int
     f1(1, 2)
           ^
-t8667.scala:27: error: too many arguments (3, expected 1) for method f1: (i: Int): Int
+t8667.scala:33: error: too many arguments (found 3, expected 1) for method f1: (i: Int): Int
     f1(1, 2, 3)
           ^
-t8667.scala:28: error: too many arguments (4, expected 1) for method f1: (i: Int): Int
+t8667.scala:34: error: too many arguments (found 4, expected 1) for method f1: (i: Int): Int
     f1(1, 2, 3, 4)
           ^
-t8667.scala:29: error: unknown parameter name: j
+t8667.scala:35: error: unknown parameter name: j
     f1(1, j = 2, 3, 4)
             ^
-t8667.scala:29: error: too many arguments (4, expected 1) for method f1: (i: Int): Int
+t8667.scala:35: error: too many arguments (found 4, expected 1) for method f1: (i: Int): Int
     f1(1, j = 2, 3, 4)
                  ^
-t8667.scala:30: error: unknown parameter name: j
+t8667.scala:36: error: unknown parameter name: j
     f1(1, j = 2, k = 3, 4)
             ^
-t8667.scala:30: error: unknown parameter name: k
+t8667.scala:36: error: unknown parameter name: k
     f1(1, j = 2, k = 3, 4)
                    ^
-t8667.scala:30: error: too many arguments (4, expected 1) for method f1: (i: Int): Int
+t8667.scala:36: error: too many arguments (found 4, expected 1) for method f1: (i: Int): Int
     f1(1, j = 2, k = 3, 4)
                         ^
-t8667.scala:31: error: unknown parameter name: k
+t8667.scala:37: error: unknown parameter name: k
     f2(k = 1, i = 2, j = 3)
          ^
-t8667.scala:31: error: too many arguments (3, expected 2) for method f2: (i: Int, j: Int): Int
+t8667.scala:37: error: too many arguments (found 3, expected 2) for method f2: (i: Int, j: Int): Int
     f2(k = 1, i = 2, j = 3)
       ^
-t8667.scala:32: error: too many arguments (7, expected 6) for method f6: (i: Int, j: Int, k: Int, l: Int, m: Int, n: Int): Int
+t8667.scala:38: error: too many arguments (found 7, expected 6) for 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:33: error: too many arguments (8, expected 6) for method f6: (i: Int, j: Int, k: Int, l: Int, m: Int, n: Int): Int
+t8667.scala:39: error: too many arguments (found 8, expected 6) for 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:34: error: too many arguments (15, 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
+t8667.scala:40: error: too many arguments (found 15, 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)
                                                ^
-t8667.scala:42: error: can't supply unit value with infix notation because nullary method f0: (): Int takes no arguments; use dotted invocation instead: x.f0()
+t8667.scala:46: error: too many arguments (found 22, expected 1) for method mini: (x: A): Int
+    mini(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
+            ^
+t8667.scala:48: error: too many arguments (found 24, which exceeds the largest Tuple) for method max: (x: Any): Int
+    max(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
+           ^
+t8667.scala:49: error: too many arguments (found 24, which exceeds the largest Tuple) for method maxi: (x: A): Int
+    maxi(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
+            ^
+t8667.scala:50: error: too many arguments (found 24, which exceeds the largest Tuple) for method moxi: (x: AnyRef): Int
+    moxi(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
+            ^
+t8667.scala:51: error: too many arguments (found 24, which exceeds the largest Tuple) for method movi: (x: Object): Int
+    movi(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
+            ^
+t8667.scala:52: error: too many arguments (found 24, expected 1) for method mini: (x: A): Int
+    mini(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
+            ^
+t8667.scala:64: error: too many arguments (found 3, expected 2-tuple) for method t: (t: (Int, Int)): Nothing
+  def z = t(42, 27, 17)
+                ^
+t8667.scala:70: error: unknown parameter name: c
+  def x = f(c = "hello, world")
+              ^
+t8667.scala:76: error: can't supply unit value with infix notation because nullary method f0: (): Int takes no arguments; use dotted invocation instead: x.f0()
     x f0 ()
       ^
-t8667.scala:43: error: no arguments allowed for nullary method f0: (): Int
+t8667.scala:77: error: no arguments allowed for nullary method f0: (): Int
     x.f0(())
          ^
-35 errors
+43 errors

test/files/neg/t8667.scala

@@ -15,11 +15,17 @@ trait T {
 }
 
 trait X {
+  trait Upper
   def f0() = 42
   def f1(i: Int) = 42
   def f2(i: Int, j: 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 max(x: Any) = 42
+  def maxi[A](x: A) = 42
+  def mini[A <: Upper](x: A) = 42
+  def moxi(x: AnyRef) = 42
+  def movi(x: Object) = 42
 
   def g() = {
     f0(1)
@@ -32,10 +38,38 @@ trait X {
     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)
+    // confirm auto-tupling
+    max(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
+    maxi(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
+    moxi(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
+    movi(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
+    mini(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
+    // clarify auto-tupling failure
+    max(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
+    maxi(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
+    moxi(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
+    movi(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
+    mini(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
     ()
   }
 }
 
+trait Y {
+  def f[A](a: A)       = ???
+  def g(x: Any)        = ???
+  def t(t: (Int, Int)) = ???
+
+  def x = f(42, 27, 17)
+  def y = g(42, 27, 17)
+  def z = t(42, 27, 17)
+}
+
+trait Z {
+  def f(a: Int = 1, b: String = "") = b * a
+
+  def x = f(c = "hello, world")
+}
+
 object app {
   def test(): Unit = {
     val x = null.asInstanceOf[X]