sema: check if @_originalDefinedIn attribute has duplicated entries for the same platform name

Author: nkcsgexi

include/swift/AST/DiagnosticsSema.def

@@ -1472,6 +1472,9 @@ WARNING(option_set_zero_constant,none,
 NOTE(option_set_empty_set_init,none,
      "use [] to silence this warning", ())
 
+ERROR(originally_defined_in_dupe_platform,none,
+      "duplicate version number for platform %0", (StringRef))
+
 // Alignment attribute
 ERROR(alignment_not_power_of_two,none,
       "alignment value must be a power of two", ())

lib/Sema/TypeCheckAttr.cpp

@@ -111,6 +111,7 @@ class AttributeChecker : public AttributeVisitor<AttributeChecker> {
   IGNORED_ATTR(DisfavoredOverload)
   IGNORED_ATTR(ProjectedValueProperty)
   IGNORED_ATTR(ReferenceOwnership)
+  IGNORED_ATTR(OriginallyDefinedIn)
 
   // TODO: Changes are yet to be upstreamed from apple/tensorflow branch.
   IGNORED_ATTR(Differentiable)
@@ -177,7 +178,6 @@ class AttributeChecker : public AttributeVisitor<AttributeChecker> {
   void visitFinalAttr(FinalAttr *attr);
   void visitIBActionAttr(IBActionAttr *attr);
   void visitIBSegueActionAttr(IBSegueActionAttr *attr);
-  void visitOriginallyDefinedInAttr(OriginallyDefinedInAttr *attr);
   void visitLazyAttr(LazyAttr *attr);
   void visitIBDesignableAttr(IBDesignableAttr *attr);
   void visitIBInspectableAttr(IBInspectableAttr *attr);
@@ -246,6 +246,7 @@ class AttributeChecker : public AttributeVisitor<AttributeChecker> {
 
   void visitImplementationOnlyAttr(ImplementationOnlyAttr *attr);
   void visitNonEphemeralAttr(NonEphemeralAttr *attr);
+  void checkOriginalDefinedInAttrs(ArrayRef<OriginallyDefinedInAttr*> Attrs);
 };
 } // end anonymous namespace
 
@@ -409,11 +410,6 @@ void AttributeChecker::visitIBActionAttr(IBActionAttr *attr) {
     validateIBActionSignature(Ctx, attr, FD, /*minParams=*/1, /*maxParams=*/1);
 }
 
-void
-AttributeChecker::visitOriginallyDefinedInAttr(OriginallyDefinedInAttr *attr) {
-  // TODO: implement diagnostics
-}
-
 void AttributeChecker::visitIBSegueActionAttr(IBSegueActionAttr *attr) {
   // Only instance methods can be IBActions.
   const FuncDecl *FD = cast<FuncDecl>(D);
@@ -1017,14 +1013,21 @@ void AttributeChecker::visitOptionalAttr(OptionalAttr *attr) {
 
 void TypeChecker::checkDeclAttributes(Decl *D) {
   AttributeChecker Checker(D);
+  // We need to check all OriginallyDefinedInAttr relative to each other, so
+  // collect them and check in batch later.
+  llvm::SmallVector<OriginallyDefinedInAttr*, 4> ODIAttrs;
   for (auto attr : D->getAttrs()) {
     if (!attr->isValid()) continue;
 
     // If Attr.def says that the attribute cannot appear on this kind of
     // declaration, diagnose it and disable it.
     if (attr->canAppearOnDecl(D)) {
-      // Otherwise, check it.
-      Checker.visit(attr);
+      if (auto *ODI = dyn_cast<OriginallyDefinedInAttr>(attr)) {
+        ODIAttrs.push_back(ODI);
+      } else {
+        // Otherwise, check it.
+        Checker.visit(attr);
+      }
       continue;
     }
 
@@ -1061,6 +1064,7 @@ void TypeChecker::checkDeclAttributes(Decl *D) {
     else
       Checker.diagnoseAndRemoveAttr(attr, diag::invalid_decl_attribute, attr);
   }
+  Checker.checkOriginalDefinedInAttrs(ODIAttrs);
 }
 
 /// Returns true if the given method is an valid implementation of a
@@ -2689,6 +2693,23 @@ void TypeChecker::checkParameterAttributes(ParameterList *params) {
   }
 }
 
+void
+AttributeChecker::checkOriginalDefinedInAttrs(
+    ArrayRef<OriginallyDefinedInAttr*> Attrs) {
+  llvm::SmallSet<PlatformKind, 4> AllPlatforms;
+  // Attrs are in the reverse order of the source order. We need to visit them
+  // in source order to diagnose the later attribute.
+  for (auto It = Attrs.rbegin(), End = Attrs.rend(); It != End; ++ It) {
+    auto *Attr = *It;
+    auto CurPlat = Attr->Platform;
+    if (!AllPlatforms.insert(CurPlat).second) {
+      // Only one version number is allowed for one platform name.
+      diagnose(Attr->AtLoc, diag::originally_defined_in_dupe_platform,
+               platformString(Attr->Platform));
+    }
+  }
+}
+
 Type TypeChecker::checkReferenceOwnershipAttr(VarDecl *var, Type type,
                                               ReferenceOwnershipAttr *attr) {
   auto &Diags = var->getASTContext().Diags;

test/Parse/original_defined_in_attr.swift

@@ -20,5 +20,11 @@ class ToplevelClass3 {}
 
 @_originallyDefinedIn(module: "foo", * 13.13) // expected-warning {{* as platform name has no effect}} expected-error {{expected at least one platform version in @_originallyDefinedIn}}
 @_originallyDefinedIn(module: "foo", OSX 13.13, iOS 7.0)
-@_originallyDefinedIn(module: "foo", OSX 13.14, * 7.0) // expected-warning {{* as platform name has no effect}}
-class ToplevelClass4 {}
+@_originallyDefinedIn(module: "foo", OSX 13.14, * 7.0) // expected-warning {{* as platform name has no effect}} expected-error {{duplicate version number for platform OSX}}
+class ToplevelClass4 {
+	@_originallyDefinedIn(module: "foo", OSX 13.13) // expected-error {{'@_originallyDefinedIn' attribute cannot be applied to this declaration}}
+	subscript(index: Int) -> Int {
+        get { return 1 }
+        set(newValue) {}
+	}
+}