[reference-bindings] Fix a verifier error and add a test that validates that we do not crash anymore.

Author: gottesmm

lib/SIL/Verifier/SILVerifier.cpp

@@ -2343,7 +2343,13 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
       else
         break;
     }
-    require(isa<AllocBoxInst>(value) || isa<SILFunctionArgument>(value),
+
+    auto isLegal = [](SILValue value) {
+      if (auto *a = dyn_cast<MarkUnresolvedReferenceBindingInst>(value))
+        value = a->getOperand();
+      return isa<AllocBoxInst>(value) || isa<SILFunctionArgument>(value);
+    };
+    require(isLegal(value),
             "Lexical borrows of SILBoxTypes must be of vars or captures.");
   }
 

test/Interpreter/reference_bindings.swift

@@ -10,12 +10,12 @@ var tests = TestSuite("reference bindings")
 
 var global: String = "globalName"
 tests.test("global access") {
-    expectEqual(global, "globalName")
-    do {
-      inout x = global
-      expectEqual(x, "globalName")
-    }
-    expectEqual(global, "globalName")
+  expectEqual(global, "globalName")
+  do {
+    inout x = global
+    expectEqual(x, "globalName")
+  }
+  expectEqual(global, "globalName")
 }
 
 tests.test("multiple global access exclusivity error")
@@ -25,63 +25,84 @@ tests.test("multiple global access exclusivity error")
 
     @inline(never)
     func test(_ x: inout String) {
-        inout x = global
+      inout x = global
     }
     test(&global)
-}
+  }
 
 tests.test("Class Instance Field Access") {
-    class Klass {
-        var name: String = "klassName"
-    }
+  class Klass {
+    var name: String = "klassName"
+  }
 
-    let k = Klass()
-    expectEqual(k.name, "klassName")
-    do {
-        inout x = k.name
-        expectEqual(x, "klassName")
-    }
-    expectEqual(k.name, "klassName")
+  let k = Klass()
+  expectEqual(k.name, "klassName")
+  do {
+    inout x = k.name
+    expectEqual(x, "klassName")
+  }
+  expectEqual(k.name, "klassName")
 }
 
 tests.test("Var Access") {
-    var varName = "varName"
-    do {
-        inout x = varName
-        expectEqual(x, "varName")
-    }
-    expectEqual(varName, "varName")
+  var varName = "varName"
+  do {
+    inout x = varName
+    expectEqual(x, "varName")
+  }
+  expectEqual(varName, "varName")
 
-    struct S {
-        var s1 = "field1"
-        var s2 = "field2"
-    }
+  struct S {
+    var s1 = "field1"
+    var s2 = "field2"
+  }
 
-    var s = S()
-    expectEqual(s.s1, "field1")
-    expectEqual(s.s2, "field2")
-    do {
-        inout x = s.s1
-        expectEqual(x, "field1")
-    }
-    expectEqual(s.s1, "field1")
-    expectEqual(s.s2, "field2")
-    do {
-        inout x2 = s.s2
-        expectEqual(x2, "field2")
-    }
-    expectEqual(s.s1, "field1")
-    expectEqual(s.s2, "field2")
+  var s = S()
+  expectEqual(s.s1, "field1")
+  expectEqual(s.s2, "field2")
+  do {
+    inout x = s.s1
+    expectEqual(x, "field1")
+  }
+  expectEqual(s.s1, "field1")
+  expectEqual(s.s2, "field2")
+  do {
+    inout x2 = s.s2
+    expectEqual(x2, "field2")
+  }
+  expectEqual(s.s1, "field1")
+  expectEqual(s.s2, "field2")
 }
 
 
 tests.test("InOut Access") {
-    var varName = "varName"
-    func inoutTest(_ inputX: inout String) {
-        expectEqual(inputX, "varName")
-        inout x = inputX
-        expectEqual(x, "varName")
+  var varName = "varName"
+  func inoutTest(_ inputX: inout String) {
+    expectEqual(inputX, "varName")
+      inout x = inputX
+    expectEqual(x, "varName")
+  }
+  inoutTest(&varName)
+  expectEqual(varName, "varName")
+}
+
+// We use to hit a verifier error here.
+tests.test("Class Use") {
+  class Klass {
+    var value: String = "varName"
+  }
+
+  struct S {
+    var k = Klass()
+    var i = 5
+    mutating func x() {
+      print("\(i)")
     }
-    inoutTest(&varName)
-    expectEqual(varName, "varName")
+  }
+
+  var s = S()
+  do {
+    inout x = s.k
+    expectEqual(x.value, "varName")
+  }
 }