Merge pull request #10784 from CodaFi/my-sweet-noescape

[SR-5296] @autoclosure and @NoEscape are not decl attributes

Author: CodaFi

include/swift/AST/Attr.def

@@ -155,8 +155,6 @@ SIMPLE_DECL_ATTR(_transparent, Transparent,
                  OnFunc|OnConstructor|OnVar|UserInaccessible, 26)
 SIMPLE_DECL_ATTR(requires_stored_property_inits, RequiresStoredPropertyInits,
                  OnClass, 27)
-DECL_ATTR(autoclosure, AutoClosure, OnParam, 28)
-SIMPLE_DECL_ATTR(noescape, NoEscape, OnParam, 29)
 
 SIMPLE_DECL_ATTR(nonobjc, NonObjC,
                  OnExtension | OnFunc | OnVar | OnSubscript | OnConstructor, 30)

include/swift/AST/Attr.h

@@ -215,20 +215,10 @@ class DeclAttribute : public AttributeBase {
   enum { NumAccessibilityAttrBits = NumDeclAttrBits + 3 };
   static_assert(NumAccessibilityAttrBits <= 32, "fits in an unsigned");
 
-  class AutoClosureAttrBitFields {
-    friend class AutoClosureAttr;
-    unsigned : NumDeclAttrBits;
-
-    unsigned Escaping : 1;
-  };
-  enum { NumAutoClosureAttrBits = NumDeclAttrBits + 1 };
-  static_assert(NumAutoClosureAttrBits <= 32, "fits in an unsigned");
-
   union {
     DeclAttrBitFields DeclAttrBits;
     ObjCAttrBitFields ObjCAttrBits;
     AccessibilityAttrBitFields AccessibilityAttrBits;
-    AutoClosureAttrBitFields AutoClosureAttrBits;
   };
 
   DeclAttribute *Next = nullptr;
@@ -916,24 +906,6 @@ class SetterAccessibilityAttr : public AbstractAccessibilityAttr {
   }
 };
 
-/// Represents the autoclosure attribute.
-class AutoClosureAttr : public DeclAttribute {
-public:
-  AutoClosureAttr(SourceLoc atLoc, SourceRange range, bool escaping,
-                  bool implicit = false)
-    : DeclAttribute(DAK_AutoClosure, atLoc, range, implicit)
-  {
-    AutoClosureAttrBits.Escaping = escaping;
-  }
-
-  /// Determine whether this autoclosure is escaping.
-  bool isEscaping() const { return AutoClosureAttrBits.Escaping; }
-
-  static bool classof(const DeclAttribute *DA) {
-    return DA->getKind() == DAK_AutoClosure;
-  }
-};
-
 /// Represents an inline attribute.
 class InlineAttr : public DeclAttribute {
   InlineKind Kind;

include/swift/AST/DiagnosticsSema.def

@@ -993,9 +993,6 @@ ERROR(missing_initializer_def,PointsToFirstBadToken,
       "initializer requires a body", ())
 
 // Attributes
-ERROR(attr_decl_attr_now_on_type,none,
-      "%0 is now an attribute on a parameter type, "
-      "instead of on the parameter itself", (StringRef))
 
 ERROR(operator_not_func,none,
       "operators must be declared with 'func'", ())
@@ -2183,20 +2180,15 @@ ERROR(rethrows_without_throwing_parameter,none,
       "'rethrows' function must take a throwing function argument", ())
 
 ERROR(autoclosure_function_type,none,
-      "@autoclosure may only be applied to values of function type",
+      "@autoclosure attribute only applies to function types",
       ())
 ERROR(autoclosure_function_input_nonunit,none,
-      "autoclosure argument type must be '()'", ())
+      "argument type of @autoclosure parameter must be '()'", ())
 
 // FIXME: drop these when we drop @noescape
-ERROR(noescape_function_type,none,
-      "@noescape may only be applied to parameters of function type",
-      ())
 ERROR(noescape_implied_by_autoclosure,none,
       "@noescape is implied by @autoclosure and should not be "
       "redundantly specified", ())
-ERROR(noescape_conflicts_escaping_autoclosure,none,
-      "@noescape conflicts with @autoclosure(escaping)", ())
 
 ERROR(escaping_non_function_parameter,none,
       "@escaping attribute may only be used in function parameter position", ())

include/swift/Migrator/FixitFilter.h

@@ -111,7 +111,6 @@ struct FixitFilter {
         Info.ID == diag::function_type_no_parens.ID ||
         Info.ID == diag::convert_let_to_var.ID ||
         Info.ID == diag::parameter_extraneous_double_up.ID ||
-        Info.ID == diag::attr_decl_attr_now_on_type.ID ||
         Info.ID == diag::noescape_parameter.ID ||
         Info.ID == diag::where_inside_brackets.ID ||
         Info.ID == diag::selector_construction_suggest.ID ||

include/swift/Serialization/ModuleFormat.h

@@ -54,7 +54,7 @@ const uint16_t VERSION_MAJOR = 0;
 /// in source control, you should also update the comment to briefly
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
-const uint16_t VERSION_MINOR = 348; // Last change: 'inout' in parameter decls.
+const uint16_t VERSION_MINOR = 349; // Last change: '@autoclosure' and '@noescape' no longer decl attributes.
 
 using DeclID = PointerEmbeddedInt<unsigned, 31>;
 using DeclIDField = BCFixed<31>;
@@ -1370,12 +1370,6 @@ namespace decls_block {
 
 #undef BC_AVAIL_TUPLE
 
-  using AutoClosureDeclAttrLayout = BCRecordLayout<
-    AutoClosure_DECL_ATTR,
-    BCFixed<1>, // implicit flag
-    BCFixed<1>  // escaping
-  >;
-
   using ObjCDeclAttrLayout = BCRecordLayout<
     ObjC_DECL_ATTR,
     BCFixed<1>, // implicit flag

lib/AST/Attr.cpp

@@ -413,12 +413,7 @@ bool DeclAttribute::printImpl(ASTPrinter &Printer, const PrintOptions &Options,
     Printer << ")";
     break;
   }
-  case DAK_AutoClosure:
-    Printer.printAttrName("@autoclosure");
-    if (cast<AutoClosureAttr>(this)->isEscaping())
-      Printer << "(escaping)";
-    break;
-      
+
   case DAK_CDecl:
     Printer << "@_cdecl(\"" << cast<CDeclAttr>(this)->Name << "\")";
     break;
@@ -568,8 +563,6 @@ StringRef DeclAttribute::getAttrName() const {
     return "_semantics";
   case DAK_Available:
     return "availability";
-  case DAK_AutoClosure:
-    return "autoclosure";
   case DAK_ObjC:
   case DAK_ObjCRuntimeName:
     return "objc";

lib/ClangImporter/ImportType.cpp

@@ -1652,15 +1652,13 @@ ParameterList *ClangImporter::Implementation::importFunctionParameterList(
       return nullptr;
 
     // Map __attribute__((noescape)) to @noescape.
-    bool addNoEscapeAttr = false;
     if (param->hasAttr<clang::NoEscapeAttr>()) {
       Type newParamTy = applyNoEscape(swiftParamTy);
       if (newParamTy.getPointer() != swiftParamTy.getPointer()) {
         swiftParamTy = newParamTy;
-        addNoEscapeAttr = true;
       }
     }
-
+    
     // Figure out the name for this parameter.
     Identifier bodyName = importFullName(param, CurrentVersion)
                               .getDeclName()
@@ -1681,11 +1679,6 @@ ParameterList *ClangImporter::Implementation::importFunctionParameterList(
         ImportedHeaderUnit);
 
     paramInfo->setInterfaceType(swiftParamTy);
-
-    if (addNoEscapeAttr)
-      paramInfo->getAttrs().add(new (SwiftContext)
-                                  NoEscapeAttr(/*IsImplicit=*/false));
-
     parameters.push_back(paramInfo);
     ++index;
   }
@@ -2123,11 +2116,6 @@ Type ClangImporter::Implementation::importMethodType(
                                            ImportedHeaderUnit);
     paramInfo->setInterfaceType(dc->mapTypeOutOfContext(swiftParamTy));
 
-    if (addNoEscapeAttr) {
-      paramInfo->getAttrs().add(
-        new (SwiftContext) NoEscapeAttr(/*IsImplicit=*/false));
-    }
-
     // Determine whether we have a default argument.
     if (kind == SpecialMethodKind::Regular ||
         kind == SpecialMethodKind::Constructor) {

lib/Parse/ParseDecl.cpp

@@ -537,36 +537,6 @@ bool Parser::parseNewDeclAttribute(DeclAttributes &Attributes, SourceLoc AtLoc,
   case DAK_Count:
     llvm_unreachable("DAK_Count should not appear in parsing switch");
 
-  case DAK_AutoClosure: {
-    // If we don't have "(escaping", it's just a bare @autoclosure.
-    if (Tok.isNot(tok::l_paren) || peekToken().getText() != "escaping") {
-      if (!DiscardAttribute)
-        Attributes.add(new (Context) AutoClosureAttr(AtLoc, Loc,
-                                                     /*escaping=*/false));
-      break;
-    }
-
-    // Consume the '('.
-    SourceLoc lParenLoc = consumeToken(tok::l_paren);
-
-    // Consume the 'escaping'.
-    (void)consumeToken();
-
-    // Parse the closing ')'.
-    SourceLoc rParenLoc;
-    parseMatchingToken(tok::r_paren, rParenLoc,
-                       diag::attr_autoclosure_expected_r_paren,
-                       lParenLoc);
-
-    // Add the attribute.
-    if (!DiscardAttribute)
-      Attributes.add(new (Context) AutoClosureAttr(AtLoc,
-                                                   SourceRange(Loc, rParenLoc),
-                                                   /*escaping=*/true));
-
-    break;
-  }
-
   case DAK_RawDocComment:
   case DAK_ObjCBridged:
   case DAK_ObjCRuntimeName:

lib/Parse/ParsePattern.cpp

@@ -345,9 +345,7 @@ mapParsedParameters(Parser &parser,
                                      paramInfo.SpecifierLoc,
                                      argNameLoc, argName,
                                      paramNameLoc, paramName, Type(),
-                                     parser.CurDeclContext);
-    param->getAttrs() = paramInfo.Attrs;
-    
+                                     parser.CurDeclContext);    
     if (argNameLoc.isInvalid() && paramNameLoc.isInvalid())
       param->setImplicit();
 

lib/Sema/TypeCheckAttr.cpp

@@ -175,13 +175,6 @@ class AttributeEarlyChecker : public AttributeVisitor<AttributeEarlyChecker> {
       TC.diagnose(attr->getLocation(), diag::alignment_not_power_of_two);
   }
 
-  void visitAutoClosureAttr(AutoClosureAttr *attr) {
-    TC.checkAutoClosureAttr(cast<ParamDecl>(D), attr);
-  }
-  void visitNoEscapeAttr(NoEscapeAttr *attr) {
-    TC.checkNoEscapeAttr(cast<ParamDecl>(D), attr);
-  }
-
   void visitTransparentAttr(TransparentAttr *attr);
   void visitMutationAttr(DeclAttribute *attr);
   void visitMutatingAttr(MutatingAttr *attr) { visitMutationAttr(attr); }
@@ -745,7 +738,6 @@ class AttributeChecker : public AttributeVisitor<AttributeChecker> {
 #define IGNORED_ATTR(CLASS)                                              \
     void visit##CLASS##Attr(CLASS##Attr *) {}
 
-    IGNORED_ATTR(AutoClosure)
     IGNORED_ATTR(Alignment)
     IGNORED_ATTR(Convenience)
     IGNORED_ATTR(Dynamic)
@@ -760,7 +752,6 @@ class AttributeChecker : public AttributeVisitor<AttributeChecker> {
     IGNORED_ATTR(Lazy)      // checked early.
     IGNORED_ATTR(LLDBDebuggerFunction)
     IGNORED_ATTR(Mutating)
-    IGNORED_ATTR(NoEscape)
     IGNORED_ATTR(NonMutating)
     IGNORED_ATTR(NonObjC)
     IGNORED_ATTR(NoReturn)
@@ -1971,117 +1962,8 @@ void TypeChecker::checkTypeModifyingDeclAttributes(VarDecl *var) {
 
   if (auto *attr = var->getAttrs().getAttribute<OwnershipAttr>())
     checkOwnershipAttr(var, attr);
-  if (auto *attr = var->getAttrs().getAttribute<AutoClosureAttr>()) {
-    if (auto *pd = dyn_cast<ParamDecl>(var))
-      checkAutoClosureAttr(pd, attr);
-    else {
-      AttributeEarlyChecker Checker(*this, var);
-      Checker.diagnoseAndRemoveAttr(attr, diag::attr_only_one_decl_kind,
-                                    attr, "parameter");
-    }
-  }
-  if (auto *attr = var->getAttrs().getAttribute<NoEscapeAttr>()) {
-    if (auto *pd = dyn_cast<ParamDecl>(var))
-      checkNoEscapeAttr(pd, attr);
-    else {
-      AttributeEarlyChecker Checker(*this, var);
-      Checker.diagnoseAndRemoveAttr(attr, diag::attr_only_one_decl_kind,
-                                    attr, "parameter");
-    }
-  }
-}
-
-
-
-void TypeChecker::checkAutoClosureAttr(ParamDecl *PD, AutoClosureAttr *attr) {
-  // The paramdecl should have function type, and we restrict it to functions
-  // taking ().
-  auto *FTy = PD->getInterfaceType()->getAs<FunctionType>();
-  if (!FTy) {
-    diagnose(attr->getLocation(), diag::autoclosure_function_type);
-    attr->setInvalid();
-    return;
-  }
-
-  // Just stop if we've already applied this attribute.
-  if (FTy->isAutoClosure())
-    return;
-
-  // This decl attribute has been moved to being a type attribute.
-  auto text = attr->isEscaping() ? "@autoclosure @escaping " : "@autoclosure ";
-  diagnose(attr->getLocation(), diag::attr_decl_attr_now_on_type,
-           "@autoclosure")
-    .fixItRemove(attr->getRangeWithAt())
-    .fixItInsert(PD->getTypeLoc().getSourceRange().Start, text);
-
-  auto *FuncTyInput = FTy->getInput()->getAs<TupleType>();
-  if (!FuncTyInput || FuncTyInput->getNumElements() != 0) {
-    diagnose(attr->getLocation(), diag::autoclosure_function_input_nonunit);
-    attr->setInvalid();
-    return;
-  }
-
-  // Change the type to include the autoclosure bit.
-  PD->setType(
-      FTy->withExtInfo(FTy->getExtInfo().withIsAutoClosure(true)));
-
-  // And the interface type.
-  auto *IfaceFTy = PD->getInterfaceType()->getAs<FunctionType>();
-  PD->setInterfaceType(
-      IfaceFTy->withExtInfo(IfaceFTy->getExtInfo().withIsAutoClosure(true)));
-
-  // Autoclosure may imply noescape, so add a noescape attribute if this is a
-  // function parameter.
-  if (auto *NEAttr = PD->getAttrs().getAttribute<NoEscapeAttr>()) {
-    // If the parameter has both @noescape and @autoclosure, reject the
-    // explicit @noescape.
-    if (!NEAttr->isImplicit())
-      diagnose(NEAttr->getLocation(),
-               attr->isEscaping()
-                 ? diag::noescape_conflicts_escaping_autoclosure
-                 : diag::noescape_implied_by_autoclosure)
-        .fixItRemove(NEAttr->getRange());
-  } else if (!attr->isEscaping()) {
-    auto *newAttr = new (Context) NoEscapeAttr(/*isImplicit*/true);
-    PD->getAttrs().add(newAttr);
-    checkNoEscapeAttr(PD, newAttr);
-  }
 }
 
-void TypeChecker::checkNoEscapeAttr(ParamDecl *PD, NoEscapeAttr *attr) {
-  // The paramdecl should have function type.
-  auto *FTy = PD->getInterfaceType()->getAs<FunctionType>();
-  if (FTy == nullptr) {
-    diagnose(attr->getLocation(), diag::noescape_function_type);
-    attr->setInvalid();
-    return;
-  }
-
-  // This range can be implicit e.g. if we're in the middle of diagnosing
-  // @autoclosure.
-  auto attrRemovalRange = attr->getRangeWithAt();
-  if (attrRemovalRange.isValid()) {
-    // Take the attribute, the '@', and the trailing space.
-    attrRemovalRange.End = attrRemovalRange.End.getAdvancedLoc(1);
-  }
-  
-  // This decl attribute has been moved to being a type attribute.
-  if (!attr->isImplicit()) {
-    diagnose(attr->getLocation(), diag::attr_decl_attr_now_on_type, "@noescape")
-        .fixItRemove(attrRemovalRange)
-        .fixItInsert(PD->getTypeLoc().getSourceRange().Start, "@noescape ");
-  }
-
-  // Stop if we've already applied this attribute.
-  if (FTy->isNoEscape())
-    return;
-
-  // Change the type to include the noescape bit.
-  PD->setType(FunctionType::get(FTy->getInput(), FTy->getResult(),
-                                FTy->getExtInfo().withNoEscape(true)));
-}
-
-
 void TypeChecker::checkOwnershipAttr(VarDecl *var, OwnershipAttr *attr) {
   Type type = var->getType();
   Type interfaceType = var->getInterfaceType();

lib/Sema/TypeCheckDecl.cpp

@@ -6153,9 +6153,6 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
     UNINTERESTING_ATTR(Specialize)
 
     // These can't appear on overridable declarations.
-    UNINTERESTING_ATTR(AutoClosure)
-    UNINTERESTING_ATTR(NoEscape)
-
     UNINTERESTING_ATTR(Prefix)
     UNINTERESTING_ATTR(Postfix)
     UNINTERESTING_ATTR(Infix)