[ConstraintSystem] In the solver, only generate constraints for wrapped

parameter attributes for closure parameters.

For regular function parameters, these constraints will have already been
generated and solved when computing the backing property wrapper type at
the function declaration. If the solver also generates these constraints
when type checking a function call, it leads to misleading diagnostics
about an argument mismatch that will appear at the function declaration
instead of the call-site.

Author: hborla

lib/Sema/CSGen.cpp

@@ -4150,7 +4150,8 @@ ConstraintSystem::applyPropertyWrapperToParameter(
 
     initKind = PropertyWrapperInitKind::ProjectedValue;
   } else {
-    generateWrappedPropertyTypeConstraints(param, wrapperType, paramType);
+    Type wrappedValueType = computeWrappedValueType(param, wrapperType);
+    addConstraint(matchKind, paramType, wrappedValueType, locator);
     initKind = PropertyWrapperInitKind::WrappedValue;
   }
 

lib/Sema/CSSimplify.cpp

@@ -8897,6 +8897,11 @@ bool ConstraintSystem::resolveClosure(TypeVariableType *typeVar,
         setType(projection, computeProjectedValueType(paramDecl, backingType));
       }
 
+      if (!paramDecl->getName().hasDollarPrefix()) {
+        generateWrappedPropertyTypeConstraints(paramDecl, backingType,
+                                               param.getParameterType());
+      }
+
       auto result = applyPropertyWrapperToParameter(backingType, param.getParameterType(),
                                                     paramDecl, paramDecl->getName(),
                                                     ConstraintKind::Equal,

test/Sema/property_wrapper_parameter_invalid.swift

@@ -86,7 +86,7 @@ struct S {
   subscript(@Wrapper position: Int) -> Int { 0 }
 }
 
-func testInvalidArgLabel() {
+func testInvalidArgLabel(projection: Projection<Int>) {
   // expected-note@+1 2 {{parameter 'argLabel' does not have an attached property wrapper}}
   func noWrappers(argLabel: Int) {}
 
@@ -95,6 +95,11 @@ func testInvalidArgLabel() {
 
   // expected-error@+1 {{cannot use property wrapper projection argument}}
   noWrappers($argLabel: 10)
+
+  func takesWrapper(@Wrapper argLabel: Int) {}
+
+  // expected-error@+1 {{cannot convert value of type 'Projection<Int>' to expected argument type 'Int'}}
+  takesWrapper(argLabel: projection)
 }
 
 protocol P {