Sema: Fix crash when @NoEscape or @autoclosure is applied to parameter

In Swift 3, these attributes were changed to apply to the type,
and not the parameter. If they appear on the parameter, we would
go down a diagnostic code path.

When checking a generic function signature, we might not have a
contextual type for the parameter yet, so bail out instead of
crashing.

Author: slavapestov

lib/Sema/TypeCheckAttr.cpp

@@ -1562,6 +1562,9 @@ void TypeChecker::checkDeclAttributes(Decl *D) {
 }
 
 void TypeChecker::checkTypeModifyingDeclAttributes(VarDecl *var) {
+  if (!var->hasType())
+    return;
+
   if (auto *attr = var->getAttrs().getAttribute<OwnershipAttr>())
     checkOwnershipAttr(var, attr);
   if (auto *attr = var->getAttrs().getAttribute<AutoClosureAttr>()) {
@@ -1589,7 +1592,7 @@ void TypeChecker::checkTypeModifyingDeclAttributes(VarDecl *var) {
 void TypeChecker::checkAutoClosureAttr(ParamDecl *PD, AutoClosureAttr *attr) {
   // The paramdecl should have function type, and we restrict it to functions
   // taking ().
-  auto *FTy = PD->getType()->getAs<FunctionType>();
+  auto *FTy = PD->getInterfaceType()->getAs<FunctionType>();
   if (!FTy) {
     diagnose(attr->getLocation(), diag::autoclosure_function_type);
     attr->setInvalid();
@@ -1643,7 +1646,7 @@ void TypeChecker::checkAutoClosureAttr(ParamDecl *PD, AutoClosureAttr *attr) {
 
 void TypeChecker::checkNoEscapeAttr(ParamDecl *PD, NoEscapeAttr *attr) {
   // The paramdecl should have function type.
-  auto *FTy = PD->getType()->getAs<FunctionType>();
+  auto *FTy = PD->getInterfaceType()->getAs<FunctionType>();
   if (FTy == nullptr) {
     diagnose(attr->getLocation(), diag::noescape_function_type);
     attr->setInvalid();

test/attr/attr_noescape.swift

@@ -330,8 +330,11 @@ enum r19997577Type {
 // type attribute and decl attribute
 func noescapeD(@noescape f: @escaping () -> Bool) {} // expected-error {{@noescape is now an attribute on a parameter type, instead of on the parameter itself}} {{16-25=}} {{29-29=@noescape }}
 func noescapeT(f: @noescape () -> Bool) {} // expected-warning{{@noescape is the default and is deprecated}} {{19-29=}}
+func noescapeG<T>(@noescape f: () -> T) {} // expected-error{{@noescape is now an attribute on a parameter type, instead of on the parameter itself}}
+
 func autoclosureD(@autoclosure f: () -> Bool) {} // expected-error {{@autoclosure is now an attribute on a parameter type, instead of on the parameter itself}} {{19-31=}} {{35-35=@autoclosure }}
 func autoclosureT(f: @autoclosure () -> Bool) {}  // ok
+func autoclosureG<T>(@autoclosure f: () -> T) {} // expected-error{{@autoclosure is now an attribute on a parameter type, instead of on the parameter itself}}
 
 func noescapeD_noescapeT(@noescape f: @noescape () -> Bool) {} // expected-error {{@noescape is now an attribute on a parameter type, instead of on the parameter itself}}
  // expected-warning@-1{{@noescape is the default and is deprecated}} {{39-49=}}

validation-test/compiler_crashers/28595-typeincontext-isnull-no-contextual-type-set-yet.swift renamed to validation-test/compiler_crashers_fixed/28595-typeincontext-isnull-no-contextual-type-set-yet.swift

@@ -5,6 +5,6 @@
 // See https://swift.org/LICENSE.txt for license information
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+// RUN: not %target-swift-frontend %s -emit-ir
 // REQUIRES: asserts
 protocol b{func a(@autoclosure())