Merge pull request #84390 from hamishknight/out-of-place

[Sema] Reject placeholders in type resolution for param and result types

include/swift/AST/DiagnosticsSema.def

@@ -4863,10 +4863,6 @@ NOTE(descriptive_generic_type_declared_here,none,
 
 ERROR(placeholder_type_not_allowed,none,
       "type placeholder not allowed here", ())
-ERROR(placeholder_type_not_allowed_in_return_type,none,
-      "type placeholder may not appear in function return type", ())
-ERROR(placeholder_type_not_allowed_in_parameter,none,
-      "type placeholder may not appear in top-level parameter", ())
 ERROR(placeholder_type_not_allowed_in_pattern,none,
       "placeholder type may not appear as type of a variable", ())
 NOTE(replace_placeholder_with_inferred_type,none,

include/swift/AST/TypeMatcher.h

@@ -117,12 +117,6 @@ private:
 #define SINGLETON_TYPE(SHORT_ID, ID) TRIVIAL_CASE(ID##Type)
 #include "swift/AST/TypeNodes.def"
 
-    bool visitPlaceholderType(CanPlaceholderType firstType, Type secondType,
-                              Type sugaredFirstType) {
-      // Placeholder types never match.
-      return mismatch(firstType.getPointer(), secondType, sugaredFirstType);
-    }
-
     bool visitUnresolvedType(CanUnresolvedType firstType, Type secondType,
                              Type sugaredFirstType) {
       // Unresolved types never match.

include/swift/Sema/CSFix.h

@@ -362,9 +362,6 @@ enum class FixKind : uint8_t {
   /// resolved.
   SpecifyTypeForPlaceholder,
 
-  /// Ignore an invalid placeholder in a decl's interface type.
-  IgnoreInvalidPlaceholderInDeclRef,
-
   /// Allow Swift -> C pointer conversion in an argument position
   /// of a Swift function.
   AllowSwiftToCPointerConversion,
@@ -3194,30 +3191,6 @@ public:
   }
 };
 
-class IgnoreInvalidPlaceholderInDeclRef final : public ConstraintFix {
-  IgnoreInvalidPlaceholderInDeclRef(ConstraintSystem &cs,
-                                    ConstraintLocator *locator)
-      : ConstraintFix(cs, FixKind::IgnoreInvalidPlaceholderInDeclRef, locator) {}
-
-public:
-  std::string getName() const override {
-    return "ignore invalid placeholder in decl ref";
-  }
-
-  bool diagnose(const Solution &solution, bool asNote = false) const override;
-
-  bool diagnoseForAmbiguity(CommonFixesArray commonFixes) const override {
-    return diagnose(*commonFixes.front().first);
-  }
-
-  static IgnoreInvalidPlaceholderInDeclRef *create(ConstraintSystem &cs,
-                                                   ConstraintLocator *locator);
-
-  static bool classof(const ConstraintFix *fix) {
-    return fix->getKind() == FixKind::IgnoreInvalidPlaceholderInDeclRef;
-  }
-};
-
 class AllowRefToInvalidDecl final : public ConstraintFix {
   AllowRefToInvalidDecl(ConstraintSystem &cs, ConstraintLocator *locator)
       : ConstraintFix(cs, FixKind::AllowRefToInvalidDecl, locator) {}