Provide fix-its when overriding a bridged value type with the old reference type (#2479) (#2753)

Merge pull request #2479 from jrose-apple/override-value-types-fix-it
(cherry picked from commit 55a97dd)

Author: jrose-apple

include/swift/AST/Decl.h

@@ -4190,7 +4190,8 @@ class VarDecl : public AbstractStorageDecl {
     return VarDeclBits.IsUserAccessible;
   }
 
-  /// \brief Retrieve the source range of the variable type.
+  /// Retrieve the source range of the variable type, or an invalid range if the
+  /// variable's type is not explicitly written in the source.
   ///
   /// Only for use in diagnostics.  It is not always possible to always
   /// precisely point to the variable type because of type aliases.

include/swift/AST/DiagnosticsSema.def

@@ -1458,6 +1458,12 @@ NOTE(subscript_override_here,none,
      "attempt to override subscript here", ())
 NOTE(convenience_init_override_here,none,
      "attempt to override convenience initializer here", ())
+NOTE(override_type_mismatch_with_fixits,none,
+     "type does not match superclass %0 with type %1",
+     (DescriptiveDeclKind, Type))
+NOTE(override_type_mismatch_with_fixits_init,none,
+     "type does not match superclass initializer with %select{no arguments|argument %1|arguments %1}0",
+     (unsigned, Type))
 ERROR(override_nonclass_decl,none,
       "'override' can only be specified on class members", ())
 ERROR(override_property_type_mismatch,none,

include/swift/AST/KnownIdentifiers.def

@@ -51,6 +51,7 @@ IDENTIFIER_(nsErrorDomain)
 IDENTIFIER(objectAtIndexedSubscript)
 IDENTIFIER(objectForKeyedSubscript)
 IDENTIFIER(ObjectiveC)
+IDENTIFIER_(ObjectiveCType)
 IDENTIFIER_(OptionalNilComparisonType)
 IDENTIFIER(parameter)
 IDENTIFIER(Protocol)

include/swift/Basic/SourceLoc.h

@@ -96,6 +96,11 @@ class SourceRange {
   bool isValid() const { return Start.isValid(); }
   bool isInvalid() const { return !isValid(); }
 
+  bool operator==(const SourceRange &other) const {
+    return Start == other.Start && End == other.End;
+  }
+  bool operator!=(const SourceRange &other) const { return !operator==(other); }
+
   /// Print out the SourceRange.  If the locations are in the same buffer
   /// as specified by LastBufferID, then we don't print the filename.  If not,
   /// we do print the filename, and then update LastBufferID with the BufferID
@@ -134,6 +139,13 @@ class CharSourceRange {
   bool isValid() const { return Start.isValid(); }
   bool isInvalid() const { return !isValid(); }
 
+  bool operator==(const CharSourceRange &other) const {
+    return Start == other.Start && ByteLength == other.ByteLength;
+  }
+  bool operator!=(const CharSourceRange &other) const {
+    return !operator==(other);
+  }
+
   SourceLoc getStart() const { return Start; }
   SourceLoc getEnd() const { return Start.getAdvancedLocOrInvalid(ByteLength); }
 

lib/AST/ASTContext.cpp

@@ -3987,9 +3987,9 @@ ASTContext::getBridgedToObjC(const DeclContext *dc, Type type,
 
   // Find the type we bridge to.
   return ProtocolConformance::getTypeWitnessByName(type,
-                                               conformance->getConcrete(),
-                                               getIdentifier("_ObjectiveCType"),
-                                               resolver);
+                                                   conformance->getConcrete(),
+                                                   Id_ObjectiveCType,
+                                                   resolver);
 }
 
 std::pair<ArchetypeBuilder *, ArchetypeBuilder::PotentialArchetype *>

lib/AST/ASTVerifier.cpp

@@ -2746,14 +2746,6 @@ struct ASTNodeBase {};
       }
       checkSourceRanges(D->getSourceRange(), Parent,
                         [&]{ D->print(Out); });
-      if (auto *VD = dyn_cast<VarDecl>(D)) {
-        if (!VD->getTypeSourceRangeForDiagnostics().isValid()) {
-          Out << "invalid type source range for variable decl: ";
-          D->print(Out);
-          Out << "\n";
-          abort();
-        }
-      }
     }
 
     /// \brief Verify that the given source ranges is contained within the

lib/AST/Decl.cpp

@@ -3369,13 +3369,14 @@ SourceRange VarDecl::getTypeSourceRangeForDiagnostics() const {
 
   Pattern *Pat = getParentPattern();
   if (!Pat || Pat->isImplicit())
-    return getSourceRange();
+    return SourceRange();
 
   if (auto *VP = dyn_cast<VarPattern>(Pat))
     Pat = VP->getSubPattern();
   if (auto *TP = dyn_cast<TypedPattern>(Pat))
     return TP->getTypeLoc().getTypeRepr()->getSourceRange();
-  return getSourceRange();
+
+  return SourceRange();
 }
 
 static bool isVarInPattern(const VarDecl *VD, Pattern *P) {

lib/PrintAsObjC/PrintAsObjC.cpp

@@ -807,7 +807,7 @@ class ObjCPrinter : private DeclVisitor<ObjCPrinter>,
     Type objcType = ProtocolConformance::getTypeWitnessByName(
                       nominal->getDeclaredType(),
                       conformance,
-                      ctx.getIdentifier("_ObjectiveCType"),
+                      ctx.Id_ObjectiveCType,
                       nullptr);
     if (!objcType) return false;
 

lib/SIL/Bridging.cpp

@@ -216,7 +216,7 @@ Type TypeConverter::getLoweredCBridgedType(AbstractionPattern pattern,
     assert(conformance && "Missing conformance?");
     Type bridgedTy =
       ProtocolConformance::getTypeWitnessByName(
-        t, conformance, M.getASTContext().getIdentifier("_ObjectiveCType"),
+        t, conformance, M.getASTContext().Id_ObjectiveCType,
         nullptr);
     assert(bridgedTy && "Missing _ObjectiveCType witness?");
     if (bridgedCollectionsAreOptional && clangTy)

lib/SILGen/SILGen.cpp

@@ -241,7 +241,7 @@ SILGenModule::getBridgedObjectiveCTypeRequirement(SILLocation loc) {
   // Look for _bridgeToObjectiveC().
   auto &ctx = getASTContext();
   AssociatedTypeDecl *found = nullptr;
-  DeclName name(ctx.getIdentifier("_ObjectiveCType"));
+  DeclName name(ctx.Id_ObjectiveCType);
   for (auto member : proto->lookupDirect(name, true)) {
     if (auto assocType = dyn_cast<AssociatedTypeDecl>(member)) {
       found = assocType;