[Property Wrappers] Store the callee in AppliedPropertyWrapperExpr to use

the correct substitution map when emitting the property wrapper generator
application in SILGen.

Author: hborla

include/swift/AST/Expr.h

@@ -4237,6 +4237,9 @@ class AppliedPropertyWrapperExpr final : public Expr {
   };
 
 private:
+  /// The concrete callee which owns the property wrapper.
+  ConcreteDeclRef Callee;
+
   /// The owning declaration.
   const ParamDecl *Param;
 
@@ -4249,18 +4252,20 @@ class AppliedPropertyWrapperExpr final : public Expr {
   /// The kind of value that the property wrapper is applied to.
   ValueKind Kind;
 
-  AppliedPropertyWrapperExpr(const ParamDecl *param, SourceLoc loc,
+  AppliedPropertyWrapperExpr(ConcreteDeclRef callee, const ParamDecl *param, SourceLoc loc,
                              Type Ty, Expr *value, ValueKind kind)
       : Expr(ExprKind::AppliedPropertyWrapper, /*Implicit=*/true, Ty),
-        Param(param), Loc(loc), Value(value), Kind(kind) {}
+        Callee(callee), Param(param), Loc(loc), Value(value), Kind(kind) {}
 
 public:
   static AppliedPropertyWrapperExpr *
-  create(ASTContext &ctx, const ParamDecl *param, SourceLoc loc,
+  create(ASTContext &ctx, ConcreteDeclRef callee, const ParamDecl *param, SourceLoc loc,
          Type Ty, Expr *value, ValueKind kind);
 
   SourceRange getSourceRange() const { return Loc; }
 
+  ConcreteDeclRef getCallee() { return Callee; }
+
   /// Returns the parameter declaration with the attached property wrapper.
   const ParamDecl *getParamDecl() const { return Param; };
 

lib/AST/Expr.cpp

@@ -1510,10 +1510,11 @@ PropertyWrapperValuePlaceholderExpr::create(ASTContext &ctx, SourceRange range,
 }
 
 AppliedPropertyWrapperExpr *
-AppliedPropertyWrapperExpr::create(ASTContext &ctx, const ParamDecl *param,
+AppliedPropertyWrapperExpr::create(ASTContext &ctx, ConcreteDeclRef callee,
+                                   const ParamDecl *param,
                                    SourceLoc loc, Type Ty, Expr *value,
                                    AppliedPropertyWrapperExpr::ValueKind kind) {
-  return new (ctx) AppliedPropertyWrapperExpr(param, loc, Ty, value, kind);
+  return new (ctx) AppliedPropertyWrapperExpr(callee, param, loc, Ty, value, kind);
 }
 
 const ParamDecl *DefaultArgumentExpr::getParamDecl() const {

lib/SILGen/SILGenExpr.cpp

@@ -5248,9 +5248,13 @@ RValue RValueEmitter::visitAppliedPropertyWrapperExpr(
     break;
   }
 
+  SubstitutionMap subs;
+  if (param->getDeclContext()->getAsDecl()) {
+    subs = E->getCallee().getSubstitutions();
+  }
+
   return SGF.emitApplyOfPropertyWrapperBackingInitializer(
-      SILLocation(E), param, SGF.getForwardingSubstitutionMap(),
-      std::move(argument), initKind);
+      SILLocation(E), param, subs, std::move(argument), initKind);
 }
 
 ProtocolDecl *SILGenFunction::getPointerProtocol() {

lib/Sema/CSApply.cpp

@@ -679,7 +679,7 @@ namespace {
              declRefExpr->getFunctionRefKind() == FunctionRefKind::Unapplied)) {
           auto &appliedWrappers = solution.appliedPropertyWrappers[locator.getAnchor()];
           result = buildPropertyWrapperFnThunk(result, fullType->getAs<FunctionType>(), fnDecl,
-                                               appliedWrappers);
+                                               ref, appliedWrappers);
         }
       }
 
@@ -978,7 +978,7 @@ namespace {
     }
 
     AutoClosureExpr *buildPropertyWrapperFnThunk(
-        Expr *fnRef, FunctionType *fnType, AnyFunctionRef fnDecl,
+        Expr *fnRef, FunctionType *fnType, AnyFunctionRef fnDecl, ConcreteDeclRef ref,
         ArrayRef<AppliedPropertyWrapper> appliedPropertyWrappers) {
       auto &context = cs.getASTContext();
       auto paramInfo = fnType->getParams();
@@ -1018,7 +1018,7 @@ namespace {
           ValueKind valueKind = (initKind == PropertyWrapperInitKind::ProjectedValue ?
                                  ValueKind::ProjectedValue : ValueKind::WrappedValue);
 
-          paramRef = AppliedPropertyWrapperExpr::create(context, innerParam,
+          paramRef = AppliedPropertyWrapperExpr::create(context, ref, innerParam,
                                                         innerParam->getStartLoc(),
                                                         wrapperType, paramRef, valueKind);
           cs.cacheExprTypes(paramRef);
@@ -1160,8 +1160,9 @@ namespace {
       auto &appliedWrappers = solution.appliedPropertyWrappers[locator.getAnchor()];
       if (!appliedWrappers.empty()) {
         auto fnDecl = AnyFunctionRef(dyn_cast<AbstractFunctionDecl>(member));
+        auto callee = resolveConcreteDeclRef(member, locator);
         auto *closure = buildPropertyWrapperFnThunk(selfCall, calleeFnType,
-                                                    fnDecl, appliedWrappers);
+                                                    fnDecl, callee, appliedWrappers);
 
         ref->setType(FunctionType::get(refTy->getParams(), selfCall->getType()));
         cs.cacheType(ref);
@@ -5841,7 +5842,7 @@ Expr *ExprRewriter::coerceCallArguments(
       ValueKind valueKind = (initKind == PropertyWrapperInitKind::ProjectedValue ?
                              ValueKind::ProjectedValue : ValueKind::WrappedValue);
 
-      arg = AppliedPropertyWrapperExpr::create(ctx, param, arg->getStartLoc(),
+      arg = AppliedPropertyWrapperExpr::create(ctx, callee, param, arg->getStartLoc(),
                                                wrapperType, arg, valueKind);
       cs.cacheExprTypes(arg);
     }
@@ -7852,7 +7853,7 @@ namespace {
 
       auto &appliedWrappers = Rewriter.solution.appliedPropertyWrappers[closure];
       return Rewriter.buildPropertyWrapperFnThunk(closure, closureFnType, closure,
-                                                  appliedWrappers);
+                                                  ConcreteDeclRef(), appliedWrappers);
     }
 
     /// Rewrite the function for the given solution.

test/SILGen/property_wrapper_parameter.swift

@@ -51,6 +51,25 @@ func simpleWrapperParameterCaller(projection: Projection<Int>) {
   // CHECK: function_ref @$s26property_wrapper_parameter26testSimpleWrapperParameter5valueyAA0F0VySiG_tFACL_SivpfW : $@convention(thin) (Projection<Int>) -> Wrapper<Int>
 }
 
+// CHECK-LABEL: sil [ossa] @$s26property_wrapper_parameter18testGenericWrapper5valueyAA0F0VyxG_tlF : $@convention(thin) <T> (@in_guaranteed Wrapper<T>) -> ()
+public func testGenericWrapper<T>(@Wrapper value: T) {
+
+  // property wrapper backing initializer of value #1 in testGenericWrapper<A>(value:)
+  // CHECK: sil non_abi [serialized] [ossa] @$s26property_wrapper_parameter18testGenericWrapper5valueyAA0F0VyxG_tlFACL_xvpfP : $@convention(thin) <T> (@in T) -> @out Wrapper<T>
+
+  // property wrapper init from projected value of value #1 in testGenericWrapper<A>(value:)
+  // CHECK: sil non_abi [serialized] [ossa] @$s26property_wrapper_parameter18testGenericWrapper5valueyAA0F0VyxG_tlFACL_xvpfW : $@convention(thin) <T> (@in Projection<T>) -> @out Wrapper<T>
+}
+
+// CHECK-LABEL: sil hidden [ossa] @$s26property_wrapper_parameter20genericWrapperCaller10projectionyAA10ProjectionVySiG_tF : $@convention(thin) (Projection<Int>) -> ()
+func genericWrapperCaller(projection: Projection<Int>) {
+  testGenericWrapper(value: projection.wrappedValue)
+  // CHECK: function_ref @$s26property_wrapper_parameter18testGenericWrapper5valueyAA0F0VyxG_tlFACL_xvpfP : $@convention(thin) <τ_0_0> (@in τ_0_0) -> @out Wrapper<τ_0_0>
+
+  testGenericWrapper($value: projection)
+  // CHECK: function_ref @$s26property_wrapper_parameter18testGenericWrapper5valueyAA0F0VyxG_tlFACL_xvpfW : $@convention(thin) <τ_0_0> (@in Projection<τ_0_0>) -> @out Wrapper<τ_0_0>
+}
+
 // CHECK-LABEL: sil hidden [ossa] @$s26property_wrapper_parameter33testSimpleClosureWrapperParameteryyF : $@convention(thin) () -> ()
 func testSimpleClosureWrapperParameter() {
   let closure: (Int) -> Void = { (@Wrapper value: Int) in