Add nullable annotations to CodeContext (#972)

Author: slozier

Src/IronPython.Modules/array.cs

@@ -1113,7 +1113,7 @@ internal arrayiterator(array a) {
             public object __iter__() => this;
 
             public object __reduce__(CodeContext context) {
-                object iter;
+                object? iter;
                 context.TryLookupBuiltin("iter", out iter);
                 if (_iterating) {
                     return PythonTuple.MakeTuple(iter, PythonTuple.MakeTuple(_array), _index + 1);

Src/IronPython/Runtime/CodeContext.cs

@@ -2,6 +2,8 @@
 // The .NET Foundation licenses this file to you under the Apache 2.0 License.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
+
 using System;
 using System.Diagnostics;
 
@@ -11,54 +13,39 @@
 using IronPython.Compiler;
 
 namespace IronPython.Runtime {
-    
+
     /// <summary>
     /// Captures and flows the state of executing code from the generated 
     /// Python code into the IronPython runtime.
     /// </summary>    
     [DebuggerTypeProxy(typeof(DebugProxy)), DebuggerDisplay("ModuleName = {ModuleName}")]
     public sealed class CodeContext {
-        private readonly ModuleContext/*!*/ _modContext;
-        private readonly PythonDictionary/*!*/ _dict;
-
         /// <summary>
         /// Creates a new CodeContext which is backed by the specified Python dictionary.
         /// </summary>
         public CodeContext(PythonDictionary/*!*/ dict, ModuleContext/*!*/ moduleContext) {
             ContractUtils.RequiresNotNull(dict, nameof(dict));
             ContractUtils.RequiresNotNull(moduleContext, nameof(moduleContext));
-            _dict = dict;
-            _modContext = moduleContext;
+            Dict = dict;
+            ModuleContext = moduleContext;
         }
 
         #region Public APIs
 
         /// <summary>
         /// Gets the module state for top-level code.
         /// </summary>   
-        public ModuleContext ModuleContext {
-            get {
-                return _modContext;
-            }
-        }
+        public ModuleContext ModuleContext { get; }
 
         /// <summary>
         /// Gets the DLR scope object that corresponds to the global variables of this context.
         /// </summary>
-        public Scope GlobalScope {
-            get {
-                return _modContext.GlobalScope;
-            }
-        }
-        
+        public Scope GlobalScope => ModuleContext.GlobalScope;
+
         /// <summary>
         /// Gets the PythonContext which created the CodeContext.
         /// </summary>
-        public PythonContext LanguageContext {
-            get {
-                return _modContext.Context;
-            }
-        }
+        public PythonContext LanguageContext => ModuleContext.Context;
 
         #endregion
 
@@ -67,12 +54,8 @@ public PythonContext LanguageContext {
         /// <summary>
         /// Gets the dictionary for the global variables from the ModuleContext.
         /// </summary>
-        internal PythonDictionary GlobalDict {
-            get {
-                return _modContext.Globals;
-            }
-        }
-       
+        internal PythonDictionary GlobalDict => ModuleContext.Globals;
+
         /// <summary>
         /// True if this global context should display CLR members on shared types (for example .ToString on int/bool/etc...)
         /// 
@@ -86,24 +69,18 @@ internal bool ShowCls {
                 ModuleContext.ShowCls = value;
             }
         }
-     
+
         /// <summary>
         /// Attempts to lookup the provided name in this scope or any outer scope.
         /// </summary>
-        internal bool TryLookupName(string name, out object value) {
-            string strName = name;
-            if (_dict.TryGetValue(strName, out value)) {
-                return true;
-            }
-
-            return _modContext.Globals.TryGetValue(strName, out value);
-        }
+        internal bool TryLookupName(string name, out object? value)
+            => Dict.TryGetValue(name, out value) || ModuleContext.Globals.TryGetValue(name, out value);
 
         /// <summary>
         /// Looks up a global variable.  If the variable is not defined in the
         /// global scope then built-ins is consulted.
         /// </summary>
-        internal bool TryLookupBuiltin(string name, out object value) {
+        internal bool TryLookupBuiltin(string name, out object? value) {
             object builtins;
             if (!GlobalDict.TryGetValue("__builtins__", out builtins)) {
                 value = null;
@@ -125,71 +102,57 @@ internal bool TryLookupBuiltin(string name, out object value) {
         /// <summary>
         /// Gets the dictionary used for storage of local variables.
         /// </summary>
-        internal PythonDictionary Dict {
-            get {
-                return _dict;
-            }
-        }
+        internal PythonDictionary Dict { get; }
 
         /// <summary>
         /// Attempts to lookup the variable in the local scope.
         /// </summary>
-        internal bool TryGetVariable(string name, out object value) {
-            return Dict.TryGetValue(name, out value);
-        }
+        internal bool TryGetVariable(string name, out object? value)
+            => Dict.TryGetValue(name, out value);
 
         /// <summary>
         /// Removes a variable from the local scope.
         /// </summary>
-        internal bool TryRemoveVariable(string name) {
-            return Dict.Remove(name);
-        }
+        internal bool TryRemoveVariable(string name)
+            => Dict.Remove(name);
 
         /// <summary>
         /// Sets a variable in the local scope.
         /// </summary>
-        internal void SetVariable(string name, object value) {
-            Dict.Add(name, value);
-        }
+        internal void SetVariable(string name, object? value)
+            => Dict.Add(name, value);
 
         /// <summary>
         /// Gets a variable from the global scope.
         /// </summary>
-        internal bool TryGetGlobalVariable(string name, out object res) {
-            return GlobalDict.TryGetValue(name, out res);
-        }
+        internal bool TryGetGlobalVariable(string name, out object? res)
+            => GlobalDict.TryGetValue(name, out res);
 
 
         /// <summary>
         /// Sets a variable in the global scope.
         /// </summary>
-        internal void SetGlobalVariable(string name, object value) {
-            GlobalDict.Add(name, value);
-        }
+        internal void SetGlobalVariable(string name, object? value)
+            => GlobalDict.Add(name, value);
 
         /// <summary>
         /// Removes a variable from the global scope.
         /// </summary>
-        internal bool TryRemoveGlobalVariable(string name) {
-            return GlobalDict.Remove(name);
-        }
+        internal bool TryRemoveGlobalVariable(string name)
+            => GlobalDict.Remove(name);
 
-        internal PythonGlobal/*!*/[] GetGlobalArray() {
-            return ((GlobalDictionaryStorage)_dict._storage).Data;
-        }
+        internal PythonGlobal/*!*/[] GetGlobalArray()
+            => ((GlobalDictionaryStorage)Dict._storage).Data;
 
-        internal bool IsTopLevel {
-            get {
-                return Dict != ModuleContext.Globals;
-            }
-        }
+        internal bool IsTopLevel
+            => Dict != ModuleContext.Globals;
 
         /// <summary>
         /// Returns the dictionary associated with __builtins__ if one is
         /// set or null if it's not available.  If __builtins__ is a module
         /// the module's dictionary is returned.
         /// </summary>
-        internal PythonDictionary GetBuiltinsDict() {
+        internal PythonDictionary? GetBuiltinsDict() {
             object builtins;
             if (GlobalDict._storage.TryGetBuiltins(out builtins)) {
                 if (builtins is PythonModule builtinsScope) {
@@ -202,17 +165,9 @@ internal PythonDictionary GetBuiltinsDict() {
             return null;
         }
 
-        internal PythonModule Module {
-            get {
-                return _modContext.Module;
-            }
-        }
+        internal PythonModule Module => ModuleContext.Module;
 
-        internal string ModuleName {
-            get {
-                return Module.GetName();
-            }
-        }
+        internal string ModuleName => Module.GetName();
 
         internal class DebugProxy {
             private readonly CodeContext _context;
@@ -222,11 +177,7 @@ public DebugProxy(CodeContext context) {
             }
 
             [DebuggerBrowsable(DebuggerBrowsableState.RootHidden)]
-            public PythonModule Members {
-                get {
-                    return _context.Module;
-                }
-            }
+            public PythonModule Members => _context.Module;
         }
 
         #endregion

Src/IronPython/Runtime/Operations/PythonOps.cs

@@ -3365,8 +3365,8 @@ public static void RemoveName(CodeContext/*!*/ context, string name) {
         /// <summary>
         /// Called from generated code, helper to do name lookup
         /// </summary>
-        public static object LookupName(CodeContext/*!*/ context, string name) {
-            object value;
+        public static object? LookupName(CodeContext/*!*/ context, string name) {
+            object? value;
             if (context.TryLookupName(name, out value)) {
                 return value;
             } else if (context.TryLookupBuiltin(name, out value)) {
@@ -3439,16 +3439,16 @@ public static object SetName(CodeContext/*!*/ context, string name, object value
             return generator.Context;
         }
 
-        public static object GetGlobal(CodeContext/*!*/ context, string name) {
+        public static object? GetGlobal(CodeContext/*!*/ context, string name) {
             return GetVariable(context, name, true, false);
         }
 
-        public static object GetLocal(CodeContext/*!*/ context, string name) {
+        public static object? GetLocal(CodeContext/*!*/ context, string name) {
             return GetVariable(context, name, false, false);
         }
 
-        internal static object GetVariable(CodeContext/*!*/ context, string name, bool isGlobal, bool lightThrow) {
-            object res;
+        internal static object? GetVariable(CodeContext/*!*/ context, string name, bool isGlobal, bool lightThrow) {
+            object? res;
             if (isGlobal) {
                 if (context.TryGetGlobalVariable(name, out res)) {
                     return res;
@@ -3459,7 +3459,7 @@ internal static object GetVariable(CodeContext/*!*/ context, string name, bool i
                 }
             }
 
-            PythonDictionary builtins = context.GetBuiltinsDict();
+            var builtins = context.GetBuiltinsDict();
             if (builtins != null && builtins.TryGetValue(name, out res)) {
                 return res;
             }
@@ -3471,16 +3471,16 @@ internal static object GetVariable(CodeContext/*!*/ context, string name, bool i
             throw ex;
         }
 
-        public static object RawGetGlobal(CodeContext/*!*/ context, string name) {
-            if (context.TryGetGlobalVariable(name, out object res)) {
+        public static object? RawGetGlobal(CodeContext/*!*/ context, string name) {
+            if (context.TryGetGlobalVariable(name, out object? res)) {
                 return res;
             }
 
             return Uninitialized.Instance;
         }
 
-        public static object RawGetLocal(CodeContext/*!*/ context, string name) {
-            if (context.TryLookupName(name, out object res)) {
+        public static object? RawGetLocal(CodeContext/*!*/ context, string name) {
+            if (context.TryLookupName(name, out object? res)) {
                 return res;
             }
 

Src/IronPython/Runtime/PythonList.cs

@@ -1374,7 +1374,7 @@ internal PythonListIterator(PythonList l) {
         #region Pickling
 
         public object __reduce__(CodeContext context) {
-            object iter;
+            object? iter;
             context.TryLookupBuiltin("iter", out iter);
             if (_iterating) {
                 return PythonTuple.MakeTuple(iter, PythonTuple.MakeTuple(_list), _index + 1);
@@ -1452,7 +1452,7 @@ public object __reduce__(CodeContext context) {
             if (_iterating) {
                 return PythonTuple.MakeTuple(Modules.Builtin.reversed, PythonTuple.MakeTuple(_list), _list._size - _index - 1);
             }
-            object iter;
+            object? iter;
             context.TryLookupBuiltin("iter", out iter);
             return PythonTuple.MakeTuple(iter, PythonTuple.MakeTuple(new PythonList()));
         }

Src/IronPython/Runtime/PythonStrIterator.cs

@@ -29,7 +29,7 @@ internal PythonStrIterator(string s) {
         }
 
         public PythonTuple __reduce__(CodeContext context) {
-            object iter;
+            object? iter;
             context.TryLookupBuiltin("iter", out iter);
             return PythonTuple.MakeTuple(
                 iter,

Src/IronPython/Runtime/PythonTuple.cs

@@ -671,7 +671,7 @@ public IEnumerator GetEnumerator() {
         #endregion
 
         public PythonTuple __reduce__(CodeContext/*!*/ context) {
-            object iter;
+            object? iter;
             context.TryLookupBuiltin("iter", out iter);
             return PythonTuple.MakeTuple(iter, PythonTuple.MakeTuple(_tuple), _curIndex + 1);
         }

Src/IronPython/Runtime/Set.cs

@@ -1474,7 +1474,7 @@ public IEnumerator GetEnumerator() {
         #endregion
 
         public PythonTuple __reduce__(CodeContext/*!*/ context) {
-            object iter;
+            object? iter;
             context.TryLookupBuiltin("iter", out iter);
             if (_cnt < 0)
                 return PythonTuple.MakeTuple(iter, PythonTuple.MakeTuple(new PythonList()));