[Variadic Generics] fixit to remove keyword 'each' on non-pack types

Author: sophiapoirier

lib/Sema/TypeCheckType.cpp

@@ -42,8 +42,9 @@
 #include "swift/Basic/SourceManager.h"
 #include "swift/Basic/Statistic.h"
 #include "swift/Basic/StringExtras.h"
-#include "swift/Sema/SILTypeResolutionContext.h"
 #include "swift/ClangImporter/ClangImporter.h"
+#include "swift/Parse/Lexer.h"
+#include "swift/Sema/SILTypeResolutionContext.h"
 #include "swift/Strings.h"
 #include "swift/Subsystems.h"
 #include "clang/AST/ASTContext.h"
@@ -4615,14 +4616,21 @@ NeverNullType TypeResolver::resolvePackElement(PackElementTypeRepr *repr,
   if (!packReference->isParameterPack()) {
     auto diag =
         ctx.Diags.diagnose(repr->getLoc(), diag::each_non_pack, packReference);
+    bool addEachFixitApplied = false;
     if (auto *packIdent = dyn_cast<IdentTypeRepr>(repr->getPackType())) {
       if (auto *packIdentBinding = packIdent->getBoundDecl()) {
         if (packIdentBinding->getLoc().isValid()) {
           diag.fixItInsert(packIdentBinding->getLoc(), "each ");
+          addEachFixitApplied = true;
         }
       }
     }
-    // TODO: else 'each' probably should be removed preceding repr
+    if (const auto eachLoc = repr->getEachLoc();
+        !addEachFixitApplied && eachLoc.isValid()) {
+      const auto eachLocEnd =
+          Lexer::getLocForEndOfToken(ctx.SourceMgr, eachLoc);
+      diag.fixItRemoveChars(eachLoc, eachLocEnd);
+    }
     return packReference;
   }
 

test/Constraints/pack-expansion-expressions.swift

@@ -153,13 +153,14 @@ func packElementInvalidBinding<each T>(_ arg: repeat each T) {
   let x = 1
   repeat print(each x)
   // expected-error@-1 {{'each' cannot be applied to non-pack type 'Int'}}
+  // TODO: fixit to remove 'each' keyword
 }
 
 func copyIntoTuple<each T>(_ arg: repeat each T) -> (repeat each T) {
   return (repeat each arg)
 }
 func callCopyAndBind<T>(_ arg: repeat each T) {
-  // expected-error@-1 {{'each' cannot be applied to non-pack type 'T'}}
+  // expected-error@-1 {{'each' cannot be applied to non-pack type 'T'}}{{22-22=each }}
   // expected-error@-2 {{pack expansion 'T' must contain at least one pack reference}}
 
   // Don't propagate errors for invalid declaration reference

test/Constraints/variadic_generic_functions.swift

@@ -21,7 +21,7 @@ func min<each T: Comparable>(_ values: repeat each T) -> (repeat each T)? {
 }
 
 func invalidPacks() {
-  func monovariadic1() -> (each String) {} // expected-error {{'each' cannot be applied to non-pack type 'String'}}
+  func monovariadic1() -> (each String) {} // expected-error {{'each' cannot be applied to non-pack type 'String'}}{{28-32=}}
   func monovariadic2<T>() -> (repeat T) {} // expected-error {{pack expansion 'T' must contain at least one pack reference}}
   func monovariadic3<T, U>() -> (T, repeat U) {} // expected-error {{pack expansion 'U' must contain at least one pack reference}}
 }

test/Constraints/variadic_generic_types.swift

@@ -22,5 +22,5 @@ func g<each T>(_: repeat each T) {
 
   _ = (repeat each Int).self
   // expected-error@-1 {{pack expansion 'Int' must contain at least one pack reference}}
-  // expected-error@-2 {{'each' cannot be applied to non-pack type 'Int'}}
+  // expected-error@-2 {{'each' cannot be applied to non-pack type 'Int'}}{{15-19=}}
 }

test/type/pack_expansion.swift

@@ -69,7 +69,7 @@ func packRef<each T>(_: repeat each T) where each T: P {}
 
 func packMemberRef<each T>(_: repeat each T.T) where each T: P {}
 
-// expected-error@+1 {{'each' cannot be applied to non-pack type 'Int'}}
+// expected-error@+1 {{'each' cannot be applied to non-pack type 'Int'}}{{31-35=}}
 func invalidPackRefEachInt(_: each Int) {}
 
 // expected-error@+1 {{pack expansion 'Int' must contain at least one pack reference}}