Macro operators without global operator lookup 5.9

lib/AST/Module.cpp

@@ -249,7 +249,7 @@ void SourceLookupCache::addToUnqualifiedLookupCache(Range decls,
         // Cache the value under both its compound name and its full name.
         TopLevelValues.add(VD);
 
-        if (VD->getAttrs().hasAttribute<CustomAttr>()) {
+        if (!onlyOperators && VD->getAttrs().hasAttribute<CustomAttr>()) {
           MayHaveAuxiliaryDecls.push_back(VD);
         }
       }
@@ -279,8 +279,10 @@ void SourceLookupCache::addToUnqualifiedLookupCache(Range decls,
     else if (auto *PG = dyn_cast<PrecedenceGroupDecl>(D))
       PrecedenceGroups[PG->getName()].push_back(PG);
 
-    else if (auto *MED = dyn_cast<MacroExpansionDecl>(D))
-      MayHaveAuxiliaryDecls.push_back(MED);
+    else if (auto *MED = dyn_cast<MacroExpansionDecl>(D)) {
+      if (!onlyOperators)
+        MayHaveAuxiliaryDecls.push_back(MED);
+    }
   }
 }
 

lib/Sema/TypeCheckProtocol.cpp

@@ -35,8 +35,10 @@
 #include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/GenericSignature.h"
 #include "swift/AST/NameLookup.h"
+#include "swift/AST/NameLookupRequests.h"
 #include "swift/AST/ParameterList.h"
 #include "swift/AST/PrettyStackTrace.h"
+#include "swift/AST/PotentialMacroExpansions.h"
 #include "swift/AST/ProtocolConformance.h"
 #include "swift/AST/TypeCheckRequests.h"
 #include "swift/AST/TypeDeclFinder.h"
@@ -1314,6 +1316,25 @@ WitnessChecker::lookupValueWitnessesViaImplementsAttr(
   removeShadowedDecls(witnesses, DC);
 }
 
+/// Determine whether the given context may expand an operator with the given name.
+static bool contextMayExpandOperator(
+    DeclContext *dc, DeclBaseName operatorName
+) {
+  TypeOrExtensionDecl decl;
+  if (auto nominal = dyn_cast<NominalTypeDecl>(dc))
+    decl = nominal;
+  else if (auto ext = dyn_cast<ExtensionDecl>(dc))
+    decl = ext;
+  else
+    return false;
+
+  ASTContext &ctx = dc->getASTContext();
+  auto potentialExpansions = evaluateOrDefault(
+      ctx.evaluator, PotentialMacroExpansionsInContextRequest{decl},
+      PotentialMacroExpansions());
+  return potentialExpansions.shouldExpandForName(operatorName);
+}
+
 SmallVector<ValueDecl *, 4>
 WitnessChecker::lookupValueWitnesses(ValueDecl *req, bool *ignoringNames) {
   assert(!isa<AssociatedTypeDecl>(req) && "Not for lookup for type witnesses*");
@@ -1331,10 +1352,12 @@ WitnessChecker::lookupValueWitnesses(ValueDecl *req, bool *ignoringNames) {
   // An operator function is the only kind of witness that requires global
   // lookup. However, because global lookup doesn't enter local contexts,
   // an additional, qualified lookup is warranted when the conforming type
-  // is declared in a local context.
+  // is declared in a local context or when the operator could come from a
+  // macro expansion.
   const bool doUnqualifiedLookup = req->isOperator();
   const bool doQualifiedLookup =
-      !req->isOperator() || DC->getParent()->getLocalContext();
+      !req->isOperator() || DC->getParent()->getLocalContext() ||
+      contextMayExpandOperator(DC, req->getName().getBaseName());
 
   if (doUnqualifiedLookup) {
     auto lookup = TypeChecker::lookupUnqualified(DC->getModuleScopeContext(),

test/Macros/Inputs/syntax_macro_definitions.swift

@@ -1505,3 +1505,63 @@ public struct SingleMemberMacro: MemberMacro {
     ]
   }
 }
+
+public struct UseIdentifierMacro: DeclarationMacro {
+  public static func expansion(
+    of node: some FreestandingMacroExpansionSyntax,
+    in context: some MacroExpansionContext
+  ) throws -> [DeclSyntax] {
+    guard let argument = node.argumentList.first?.expression.as(StringLiteralExprSyntax.self) else {
+      fatalError("boom")
+    }
+    return [
+      """
+      func \(context.makeUniqueName("name"))() {
+        _ = \(raw: argument.segments.first!)
+      }
+      """,
+      """
+      struct Foo {
+        var \(context.makeUniqueName("name")): Int {
+          _ = \(raw: argument.segments.first!)
+          return 0
+        }
+      }
+      """
+    ]
+  }
+}
+
+public struct StaticFooFuncMacro: DeclarationMacro {
+  public static func expansion(
+    of node: some FreestandingMacroExpansionSyntax,
+    in context: some MacroExpansionContext
+  ) throws -> [DeclSyntax] {
+    return [
+      "static func foo() {}",
+    ]
+  }
+}
+
+public struct SelfAlwaysEqualOperator: DeclarationMacro {
+  public static func expansion(
+    of node: some FreestandingMacroExpansionSyntax,
+    in context: some MacroExpansionContext
+  ) throws -> [DeclSyntax] {
+    return [
+      "static func ==(lhs: Self, rhs: Bool) -> Bool { true }",
+    ]
+  }
+}
+
+extension SelfAlwaysEqualOperator: MemberMacro {
+  public static func expansion(
+    of node: AttributeSyntax,
+    providingMembersOf decl: some DeclGroupSyntax,
+    in context: some MacroExpansionContext
+  ) throws -> [DeclSyntax] {
+    return [
+      "static func ==(lhs: Self, rhs: Bool) -> Bool { true }",
+    ]
+  }
+}

test/Macros/macro_expand.swift

@@ -24,7 +24,7 @@
 // RUN: %target-swift-frontend -swift-version 5 -emit-ir -load-plugin-library %t/%target-library-name(MacroDefinition) %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-IR %s
 
 // Execution testing
-// RUN: %target-build-swift -swift-version 5 -g -load-plugin-library %t/%target-library-name(MacroDefinition) %s -o %t/main -module-name MacroUser
+// RUN: %target-build-swift -swift-version 5 -g -load-plugin-library %t/%target-library-name(MacroDefinition) %s -o %t/main -module-name MacroUser -Xfrontend -emit-dependencies-path -Xfrontend %t/main.d -Xfrontend -emit-reference-dependencies-path -Xfrontend %t/main.swiftdeps
 // RUN: %target-codesign %t/main
 // RUN: %target-run %t/main | %FileCheck %s
 
@@ -417,3 +417,89 @@ func testFreestandingClosureNesting() {
 func testLocalVarsFromDeclarationMacros() {
   #varValue
 }
+
+// Variadic macro
+@freestanding(declaration, names: arbitrary) macro emptyDecl(_: String...) = #externalMacro(module: "MacroDefinition", type: "EmptyDeclarationMacro")
+
+struct TakesVariadic {
+  #emptyDecl("foo", "bar")
+}
+
+// Funkiness with static functions introduced via macro expansions.
+@freestanding(declaration, names: named(foo())) public macro staticFooFunc() = #externalMacro(module: "MacroDefinition", type: "StaticFooFuncMacro")
+@freestanding(declaration, names: arbitrary) public macro staticFooFuncArbitrary() = #externalMacro(module: "MacroDefinition", type: "StaticFooFuncMacro")
+
+class HasAnExpandedStatic {
+  #staticFooFunc()
+}
+
+class HasAnExpandedStatic2 {
+  #staticFooFuncArbitrary()
+}
+
+func testHasAnExpandedStatic() {
+#if TEST_DIAGNOSTICS
+  foo() // expected-error{{cannot find 'foo' in scope}}
+#endif
+}
+
+@freestanding(declaration, names: named(==)) public macro addSelfEqualsOperator() = #externalMacro(module: "MacroDefinition", type: "SelfAlwaysEqualOperator")
+@freestanding(declaration, names: arbitrary) public macro addSelfEqualsOperatorArbitrary() = #externalMacro(module: "MacroDefinition", type: "SelfAlwaysEqualOperator")
+@attached(member, names: named(==)) public macro AddSelfEqualsMemberOperator() = #externalMacro(module: "MacroDefinition", type: "SelfAlwaysEqualOperator")
+@attached(member, names: arbitrary) public macro AddSelfEqualsMemberOperatorArbitrary() = #externalMacro(module: "MacroDefinition", type: "SelfAlwaysEqualOperator")
+
+struct HasEqualsSelf {
+  #addSelfEqualsOperator
+}
+
+struct HasEqualsSelf2 {
+  #addSelfEqualsOperatorArbitrary
+}
+
+@AddSelfEqualsMemberOperator
+struct HasEqualsSelf3 {
+}
+
+@AddSelfEqualsMemberOperatorArbitrary
+struct HasEqualsSelf4 {
+}
+
+protocol SelfEqualsBoolProto { // expected-note 4{{where 'Self' =}}
+  static func ==(lhs: Self, rhs: Bool) -> Bool
+}
+
+struct HasEqualsSelfP: SelfEqualsBoolProto {
+  #addSelfEqualsOperator
+}
+
+struct HasEqualsSelf2P: SelfEqualsBoolProto {
+  #addSelfEqualsOperatorArbitrary
+}
+
+@AddSelfEqualsMemberOperator
+struct HasEqualsSelf3P: SelfEqualsBoolProto {
+}
+
+@AddSelfEqualsMemberOperatorArbitrary
+struct HasEqualsSelf4P: SelfEqualsBoolProto {
+}
+
+func testHasEqualsSelf(
+  x: HasEqualsSelf, y: HasEqualsSelf2, z: HasEqualsSelf3, w: HasEqualsSelf4,
+  xP: HasEqualsSelfP, yP: HasEqualsSelf2P, zP: HasEqualsSelf3P,
+  wP: HasEqualsSelf4P
+) {
+#if TEST_DIAGNOSTICS
+  // Global operator lookup doesn't find member operators introduced by macros.
+  _ = (x == true) // expected-error{{referencing operator function '=='}}
+  _ = (y == true) // expected-error{{referencing operator function '=='}}
+  _ = (z == true) // expected-error{{referencing operator function '=='}}
+  _ = (w == true) // expected-error{{referencing operator function '=='}}
+  #endif
+
+  // These should be found through the protocol.
+  _ = (xP == true)
+  _ = (yP == true)
+  _ = (zP == true)
+  _ = (wP == true)
+}

test/Macros/macro_expand_primary.swift

@@ -85,3 +85,13 @@ final class Dog: Observable {
 func test() {
   observeDog()
 }
+
+
+@freestanding(declaration, names: named(Foo)) macro useIdentifier(_ value: String) = #externalMacro(module: "MacroDefinition", type: "UseIdentifierMacro")
+
+#if false
+#useIdentifier("totallyNotDefined")
+#else
+let hello = "Hello"
+#useIdentifier("hello")
+#endif