[Macros] Apply expanded attributes to the member's semantic attribute list.

This change enables the first end-to-end test for member attribute macros!

Author: hborla

lib/Sema/TypeCheckAttr.cpp

@@ -3609,6 +3609,10 @@ void AttributeChecker::visitCustomAttr(CustomAttr *attr) {
   // If the nominal type is a property wrapper type, we can be delegating
   // through a property.
   if (nominal->getAttrs().hasAttribute<PropertyWrapperAttr>()) {
+    // FIXME: We shouldn't be type checking missing decls.
+    if (isa<MissingDecl>(D))
+      return;
+
     // property wrappers can only be applied to variables
     if (!isa<VarDecl>(D)) {
       diagnose(attr->getLocation(),
@@ -7414,10 +7418,7 @@ AttachedSemanticAttrsRequest::evaluate(Evaluator &evaluator, Decl *decl) const {
     if (!macroDecl->getMacroRoles().contains(MacroRole::MemberAttribute))
       continue;
 
-    // Expand the attributes.
-    expandAttributes(customAttr, macroDecl, decl);
-
-    // TODO: append the expanded attributes to 'semanticAttrs'.
+    expandAttributes(customAttr, macroDecl, decl, semanticAttrs);
   }
 
   return semanticAttrs;

lib/Sema/TypeCheckDeclPrimary.cpp

@@ -1993,7 +1993,10 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
   }
 
   void visitMissingDecl(MissingDecl *missing) {
-    // nothing to do for missing decls.
+    // FIXME: Expanded attribute lists should be type checked against
+    // the real declaration they will be attached to. Attempting to
+    // type check a missing decl should produce an error.
+    TypeChecker::checkDeclAttributes(missing);
   }
 
   void visitMissingMemberDecl(MissingMemberDecl *MMD) {

lib/Sema/TypeCheckMacros.cpp

@@ -842,8 +842,8 @@ void swift::expandAccessors(
 // FIXME: Almost entirely duplicated code from `expandAccessors`.
 // Factor this out into an `expandAttachedMacro` function, with
 // arguments for the PrettyStackTrace string, 'attachedTo' decl, etc.
-void swift::expandAttributes(
-    CustomAttr *attr, MacroDecl *macro, Decl *member) {
+void swift::expandAttributes(CustomAttr *attr, MacroDecl *macro, Decl *member,
+                             SemanticDeclAttributes &result) {
   auto *dc = member->getInnermostDeclContext();
   ASTContext &ctx = dc->getASTContext();
   SourceManager &sourceMgr = ctx.SourceMgr;
@@ -1004,6 +1004,17 @@ void swift::expandAttributes(
       "type checking expanded declaration macro", member);
 
   auto topLevelDecls = macroSourceFile->getTopLevelDecls();
+  for (auto decl : topLevelDecls) {
+    // FIXME: We want to type check decl attributes applied to
+    // the real declaration, ideally by appending the new attributes
+    // to the result and changing TypeChecker::checkDeclAttributes
+    // to use the semantic attribute list.
+    decl->setDeclContext(dc);
+    TypeChecker::typeCheckDecl(decl);
 
-  // TODO: Return the attribute lists attached to top-level decls.
+    // Add the new attributes to the semantic attribute list.
+    for (auto *attr : decl->getAttrs()) {
+      result.add(attr);
+    }
+  }
 }

lib/Sema/TypeCheckMacros.h

@@ -16,6 +16,7 @@
 #ifndef SWIFT_SEMA_TYPECHECKMACROS_H
 #define SWIFT_SEMA_TYPECHECKMACROS_H
 
+#include "swift/AST/Attr.h"
 #include "swift/AST/ConcreteDeclRef.h"
 #include "swift/AST/Type.h"
 
@@ -50,8 +51,8 @@ void expandAccessors(
 
 /// Expand the attributes for the given member declaration based
 /// on the custom attribute that references the given macro.
-void expandAttributes(
-    CustomAttr *attr, MacroDecl *macro, Decl *member);
+void expandAttributes(CustomAttr *attr, MacroDecl *macro, Decl *member,
+                      SemanticDeclAttributes &result);
 
 } // end namespace swift
 

test/Macros/macro_expand_attributes.swift

@@ -2,6 +2,9 @@
 // RUN: %target-build-swift -I %swift-host-lib-dir -L %swift-host-lib-dir -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift -g -no-toolchain-stdlib-rpath
 // RUNx: %target-swift-frontend -dump-ast -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir %s -module-name MacroUser 2>&1 | %FileCheck --check-prefix CHECK-AST %s
 // RUN: %target-typecheck-verify-swift -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir -module-name MacroUser -DTEST_DIAGNOSTICS -swift-version 5
+// RUN: %target-build-swift -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir -L %swift-host-lib-dir %s -o %t/main -module-name MacroUser -swift-version 5
+// RUN: %target-run %t/main | %FileCheck %s
+// REQUIRES: executable_test
 
 // FIXME: Swift parser is not enabled on Linux CI yet.
 // REQUIRES: OS=macosx
@@ -10,11 +13,27 @@
 
 @propertyWrapper
 struct Wrapper<T> {
-  var wrappedValue: T
+  init(wrappedValue: T) {
+    print("initializing wrapper with \(wrappedValue)")
+    self.wrappedValue = wrappedValue
+  }
+  var wrappedValue: T {
+    willSet { print("setting \(newValue)") }
+  }
 }
 
 @wrapAllProperties
 struct S {
   var x: Int
   var y: Int
 }
+
+// CHECK: initializing wrapper with 0
+// CHECK: initializing wrapper with 1
+var s = S(x: 0, y: 1)
+
+// CHECK: setting 10
+s.x = 10
+
+// CHECK: setting 100
+s.y = 100