Merge pull request swiftlang#84142 from hamishknight/for-none

[CS] NFC: Remove `CTP_ForEachStmt`

Author: hamishknight

include/swift/Sema/ConstraintLocator.h

@@ -76,12 +76,7 @@ enum ContextualTypePurpose : uint8_t {
   CTP_CaseStmt,         ///< A single case statement associated with a `switch` or
                         ///  a `do-catch` statement. It has to be convertible
                         ///  to a type of a switch subject or an `Error` type.
-  CTP_ForEachStmt,      ///< "expression/sequence" associated with 'for-in' loop
-                        ///< is expected to conform to 'Sequence' protocol.
-  CTP_ForEachSequence,  ///< Sequence expression associated with `for-in` loop,
-                        ///  this element acts slightly differently compared to
-                        ///  \c CTP_ForEachStmt in a sence that it would
-                        ///  produce conformance constraints.
+  CTP_ForEachSequence,  ///< Sequence expression associated with `for-in` loop.
   CTP_WrappedProperty,  ///< Property type expected to match 'wrappedValue' type
   CTP_ComposedPropertyWrapper, ///< Composed wrapper type expected to match
                                ///< former 'wrappedValue' type

include/swift/Sema/SyntacticElementTarget.h

@@ -601,7 +601,6 @@ class SyntacticElementTarget {
 
     switch (getExprContextualTypePurpose()) {
     case CTP_Initialization:
-    case CTP_ForEachStmt:
     case CTP_ForEachSequence:
     case CTP_ExprPattern:
       break;

lib/Sema/CSApply.cpp

@@ -9783,7 +9783,6 @@ ExprWalker::rewriteTarget(SyntacticElementTarget target) {
     case CTP_CaseStmt:
     case CTP_ReturnStmt:
     case CTP_ExprPattern:
-    case CTP_ForEachStmt:
     case CTP_ForEachSequence:
     case CTP_YieldByValue:
     case CTP_YieldByReference:

lib/Sema/CSDiagnostics.cpp

@@ -884,7 +884,6 @@ GenericArgumentsMismatchFailure::getDiagnosticFor(
 
   case CTP_CaseStmt:
   case CTP_ThrowStmt:
-  case CTP_ForEachStmt:
   case CTP_ForEachSequence:
   case CTP_ComposedPropertyWrapper:
   case CTP_Unused:
@@ -2787,7 +2786,7 @@ bool ContextualFailure::diagnoseAsError() {
       }
     }
 
-    if (CTP == CTP_ForEachStmt || CTP == CTP_ForEachSequence) {
+    if (CTP == CTP_ForEachSequence) {
       if (fromType->isAnyExistentialType()) {
         Type constraintType = fromType;
         if (auto existential = constraintType->getAs<ExistentialType>())
@@ -2986,7 +2985,6 @@ getContextualNilDiagnostic(ContextualTypePurpose CTP) {
   case CTP_CaseStmt:
   case CTP_ThrowStmt:
   case CTP_DiscardStmt:
-  case CTP_ForEachStmt:
   case CTP_ForEachSequence:
   case CTP_YieldByReference:
   case CTP_WrappedProperty:
@@ -3774,7 +3772,6 @@ ContextualFailure::getDiagnosticFor(ContextualTypePurpose context,
     return diag::cannot_match_value_with_pattern;
 
   case CTP_ThrowStmt:
-  case CTP_ForEachStmt:
   case CTP_ForEachSequence:
   case CTP_ComposedPropertyWrapper:
   case CTP_Unused:
@@ -6610,8 +6607,7 @@ bool CollectionElementContextualFailure::diagnoseAsError() {
     // If this is a conversion failure related to binding of `for-each`
     // statement it has to be diagnosed as pattern match if there are
     // holes present in the contextual type.
-    if ((purpose == ContextualTypePurpose::CTP_ForEachStmt ||
-         purpose == ContextualTypePurpose::CTP_ForEachSequence) &&
+    if (purpose == ContextualTypePurpose::CTP_ForEachSequence &&
         contextualType->hasUnresolvedType()) {
       auto diagnostic = emitDiagnostic(
           (contextualType->is<TupleType>() && !eltType->is<TupleType>())

lib/Sema/CSSimplify.cpp

@@ -16550,7 +16550,6 @@ void ConstraintSystem::addContextualConversionConstraint(
   case CTP_DictionaryValue:
   case CTP_CoerceOperand:
   case CTP_SubscriptAssignSource:
-  case CTP_ForEachStmt:
   case CTP_WrappedProperty:
   case CTP_ComposedPropertyWrapper:
   case CTP_ExprPattern:

lib/Sema/SyntacticElementTarget.cpp

@@ -261,7 +261,6 @@ bool SyntacticElementTarget::contextualTypeIsOnlyAHint() const {
   switch (getExprContextualTypePurpose()) {
   case CTP_Initialization:
     return !infersOpaqueReturnType() && !isOptionalSomePatternInit();
-  case CTP_ForEachStmt:
   case CTP_ForEachSequence:
     return true;
   case CTP_Unused: