[Sema] Upgrade tuple shuffle warning to error in future lang mode

This has been deprecated for a while now, flip it to an error for a
future language mode.

Author: hamishknight

include/swift/AST/DiagnosticsSema.def

@@ -7833,8 +7833,13 @@ ERROR(result_builder_buildpartialblock_accumulated_not_accessible,none,
 // MARK: Tuple Shuffle Diagnostics
 //------------------------------------------------------------------------------
 
+ERROR(reordering_tuple_shuffle,none,
+      "cannot implicitly reorder tuple elements from '%0' to '%1'",
+      (StringRef, StringRef))
+
 WARNING(warn_reordering_tuple_shuffle_deprecated,Deprecation,
-        "implicit reordering of tuple elements from '%0' to '%1' is deprecated",
+        "implicit reordering of tuple elements from '%0' to '%1' is deprecated"
+        "; this will be an error in a future Swift language mode",
         (StringRef, StringRef))
 
 //------------------------------------------------------------------------------

lib/Sema/CSApply.cpp

@@ -5867,9 +5867,15 @@ Expr *ExprRewriter::coerceTupleToTuple(Expr *expr,
     SmallString<16> toLabelStr;
     concatLabels(labels, toLabelStr);
 
-    ctx.Diags.diagnose(expr->getLoc(),
-                       diag::warn_reordering_tuple_shuffle_deprecated,
-                       fromLabelStr, toLabelStr);
+    using namespace version;
+    if (ctx.isSwiftVersionAtLeast(Version::getFutureMajorLanguageVersion())) {
+      ctx.Diags.diagnose(expr->getLoc(), diag::reordering_tuple_shuffle,
+                         fromLabelStr, toLabelStr);
+    } else {
+      ctx.Diags.diagnose(expr->getLoc(),
+                         diag::warn_reordering_tuple_shuffle_deprecated,
+                         fromLabelStr, toLabelStr);
+    }
   }
 
   // Create the result tuple, written in terms of the destructured

test/Constraints/tuple_shuffle.swift

@@ -1,36 +1,50 @@
-// RUN: %target-typecheck-verify-swift -swift-version 5
+// RUN: %target-typecheck-verify-swift -swift-version 6 -verify-additional-prefix swift6-
+// RUN: %target-typecheck-verify-swift -swift-version 7 -verify-additional-prefix swift7-
+
+// REQUIRES: swift7
 
 func consume<T>(_ x: T) {} // Suppress unused variable warnings
 
 func shuffle_through_initialization() {
   let a = (x: 1, y: 2)
   let b: (y: Int, x: Int)
-  b = a // expected-warning {{implicit reordering of tuple elements from 'x:y:' to 'y:x:' is deprecated}}
+  b = a
+  // expected-swift6-warning@-1 {{implicit reordering of tuple elements from 'x:y:' to 'y:x:' is deprecated; this will be an error in a future Swift language mode}}
+  // expected-swift7-error@-2 {{cannot implicitly reorder tuple elements from 'x:y:' to 'y:x:'}}
   consume(b)
 }
 
 func shuffle_raw_label(_ t: (`a b`: Int, `c d`: Int)) {
   let _: (`c d`: Int, `a b`: Int) = t
-  // expected-warning@-1 {{implicit reordering of tuple elements from '`a b`:`c d`:' to '`c d`:`a b`:' is deprecated}}
+  // expected-swift6-warning@-1 {{implicit reordering of tuple elements from '`a b`:`c d`:' to '`c d`:`a b`:' is deprecated; this will be an error in a future Swift language mode}}
+  // expected-swift7-error@-2 {{cannot implicitly reorder tuple elements from '`a b`:`c d`:' to '`c d`:`a b`:'}}
 }
 
 func shuffle_through_destructuring() {
   let a = (x: 1, y: 2)
-  let (y: b, x: c) = a // expected-warning {{implicit reordering of tuple elements from 'x:y:' to 'y:x:' is deprecated}}
+  let (y: b, x: c) = a
+  // expected-swift6-warning@-1 {{implicit reordering of tuple elements from 'x:y:' to 'y:x:' is deprecated; this will be an error in a future Swift language mode}}
+  // expected-swift7-error@-2 {{cannot implicitly reorder tuple elements from 'x:y:' to 'y:x:'}}
   consume((b, c))
 }
 
 func shuffle_through_call() {
   func foo(_ : (x: Int, y: Int)) {}
-  foo((y: 5, x: 10)) // expected-warning {{implicit reordering of tuple elements from 'y:x:' to 'x:y:' is deprecated}}
+  foo((y: 5, x: 10))
+  // expected-swift6-warning@-1 {{implicit reordering of tuple elements from 'y:x:' to 'x:y:' is deprecated; this will be an error in a future Swift language mode}}
+  // expected-swift7-error@-2 {{cannot implicitly reorder tuple elements from 'y:x:' to 'x:y:'}}
 }
 
 func shuffle_through_cast() {
-  let x = ((a: Int(), b: Int()) as (b: Int, a: Int)).0 // expected-warning {{implicit reordering of tuple elements from 'a:b:' to 'b:a:' is deprecated}}
+  let x = ((a: Int(), b: Int()) as (b: Int, a: Int)).0
+  // expected-swift6-warning@-1 {{implicit reordering of tuple elements from 'a:b:' to 'b:a:' is deprecated; this will be an error in a future Swift language mode}}
+  // expected-swift7-error@-2 {{cannot implicitly reorder tuple elements from 'a:b:' to 'b:a:'}}
 
   // Ah, the famous double-shuffle
   let (c1, (c2, c3)): (c: Int, (b: Int, a: Int)) = ((a: Int(), b: Int()), c: Int())
-  // expected-warning@-1 {{implicit reordering of tuple elements from 'a:b:' to 'b:a:' is deprecated}}
-  // expected-warning@-2 {{implicit reordering of tuple elements from '_:c:' to 'c:_:' is deprecated}}
+  // expected-swift6-warning@-1 {{implicit reordering of tuple elements from 'a:b:' to 'b:a:' is deprecated; this will be an error in a future Swift language mode}}
+  // expected-swift6-warning@-2 {{implicit reordering of tuple elements from '_:c:' to 'c:_:' is deprecated; this will be an error in a future Swift language mode}}
+  // expected-swift7-error@-3 {{cannot implicitly reorder tuple elements from 'a:b:' to 'b:a:'}}
+  // expected-swift7-error@-4 {{cannot implicitly reorder tuple elements from '_:c:' to 'c:_:'}}
   consume((x, c1, c2, c3))
 }

test/Parse/omit_return.swift

@@ -474,7 +474,7 @@ func ff_implicitInjectIntoOptionalExpr(_ int: Int) -> Int? {
 }
 
 func ff_implicitTupleShuffle(_ input: (one: Int, two: Int)) -> (two: Int, one: Int) {
-    input // expected-warning {{implicit reordering of tuple elements from 'one:two:' to 'two:one:' is deprecated}}
+    input // expected-warning {{implicit reordering of tuple elements from 'one:two:' to 'two:one:' is deprecated; this will be an error in a future Swift language mode}}
 }
 
 func ff_implicitCollectionUpcast(_ derived: [Derived]) -> [Base] {

test/Parse/omit_return_ifdecl.swift

@@ -676,7 +676,7 @@ func ff_implicitInjectIntoOptionalExpr(_ int: Int) -> Int? {
 
 func ff_implicitTupleShuffle(_ input: (one: Int, two: Int)) -> (two: Int, one: Int) {
     #if true
-    input // expected-warning {{implicit reordering of tuple elements from 'one:two:' to 'two:one:' is deprecated}}
+    input // expected-warning {{implicit reordering of tuple elements from 'one:two:' to 'two:one:' is deprecated; this will be an error in a future Swift language mode}}
     #endif
 }
 

test/Sema/diag_unowned_immediate_deallocation.swift

@@ -452,10 +452,10 @@ func testGenericWeakClassDiag() {
 // The diagnostic doesn't currently support tuple shuffles.
 func testDontDiagnoseThroughTupleShuffles() {
   unowned let (c1, (c2, c3)): (c: C, (b: C, a: C)) = ((a: D(), b: C()), c: D())
-  // expected-warning@-1 {{implicit reordering of tuple elements from 'a:b:' to 'b:a:' is deprecated}}
-  // expected-warning@-2 {{implicit reordering of tuple elements from '_:c:' to 'c:_:' is deprecated}}
+  // expected-warning@-1 {{implicit reordering of tuple elements from 'a:b:' to 'b:a:' is deprecated; this will be an error in a future Swift language mode}}
+  // expected-warning@-2 {{implicit reordering of tuple elements from '_:c:' to 'c:_:' is deprecated; this will be an error in a future Swift language mode}}
   unowned let c4 = ((a: C(), b: C()) as (b: C, a: C)).0
-  // expected-warning@-1 {{implicit reordering of tuple elements from 'a:b:' to 'b:a:' is deprecated}}
+  // expected-warning@-1 {{implicit reordering of tuple elements from 'a:b:' to 'b:a:' is deprecated; this will be an error in a future Swift language mode}}
 
   _ = c1; _ = c2; _ = c3; _ = c4
 }

test/decl/func/operator.swift

@@ -155,7 +155,7 @@ var f2 : (Int) -> Int = (+-+)
 var f3 : (inout Int) -> Int = (-+-) // expected-error{{ambiguous use of operator '-+-'}}
 var f4 : (inout Int, Int) -> Int = (+-+=)
 var r5 : (a : (Int, Int) -> Int, b : (Int, Int) -> Int) = (+, -)
-var r6 : (a : (Int, Int) -> Int, b : (Int, Int) -> Int) = (b : +, a : -) // expected-warning {{implicit reordering of tuple elements from 'b:a:' to 'a:b:' is deprecated}}
+var r6 : (a : (Int, Int) -> Int, b : (Int, Int) -> Int) = (b : +, a : -) // expected-warning {{implicit reordering of tuple elements from 'b:a:' to 'a:b:' is deprecated; this will be an error in a future Swift language mode}}
 
 struct f6_S {
   subscript(op : (Int, Int) -> Int) -> Int {

test/expr/closure/closures.swift

@@ -56,7 +56,7 @@ func funcdecl5(_ a: Int, _ y: Int) {
   var b = a.1+a.f
 
   // Tuple expressions with named elements.
-  var i : (y : Int, x : Int) = (x : 42, y : 11) // expected-warning {{implicit reordering of tuple elements from 'x:y:' to 'y:x:' is deprecated}}
+  var i : (y : Int, x : Int) = (x : 42, y : 11) // expected-warning {{implicit reordering of tuple elements from 'x:y:' to 'y:x:' is deprecated; this will be an error in a future Swift language mode}}
   funcdecl1(123, 444)
 
   // Calls.

test/expr/expressions.swift

@@ -194,7 +194,7 @@ func test5() {
 
 
   let c: (a: Int, b: Int) = (1,2)
-  let _: (b: Int, a: Int) = c  // expected-warning {{implicit reordering of tuple elements from 'a:b:' to 'b:a:' is deprecated}}
+  let _: (b: Int, a: Int) = c  // expected-warning {{implicit reordering of tuple elements from 'a:b:' to 'b:a:' is deprecated; this will be an error in a future Swift language mode}}
 }