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//
// eval.cs: Evaluation and Hosting API for the C# compiler
//
// Authors:
// Miguel de Icaza (miguel@gnome.org)
// Marek Safar (marek.safar@gmail.com)
//
// Dual licensed under the terms of the MIT X11 or GNU GPL
//
// Copyright 2001, 2002, 2003 Ximian, Inc (http://www.ximian.com)
// Copyright 2004-2011 Novell, Inc
// Copyright 2011 Xamarin Inc
//
using System;
using System.Threading;
using System.Collections.Generic;
using System.Reflection;
using System.Reflection.Emit;
using System.IO;
using System.Text;
using System.Linq;
namespace Mono.CSharp
{
/// <summary>
/// Experimental!
/// </summary>
public delegate void ValueModificationHandler (string variableName, int row, int column, object value);
/// <summary>
/// Evaluator: provides an API to evaluate C# statements and
/// expressions dynamically.
/// </summary>
/// <remarks>
/// This class exposes static methods to evaluate expressions in the
/// current program.
///
/// To initialize the evaluator with a number of compiler
/// options call the Init(string[]args) method with a set of
/// command line options that the compiler recognizes.
///
/// To interrupt execution of a statement, you can invoke the
/// Evaluator.Interrupt method.
/// </remarks>
public class Evaluator {
enum ParseMode {
// Parse silently, do not output any error messages
Silent,
// Report errors during parse
ReportErrors,
// Auto-complete, means that the tokenizer will start producing
// GETCOMPLETIONS tokens when it reaches a certain point.
GetCompletions
}
static object evaluator_lock = new object ();
static volatile bool invoking;
#if !STATIC
static int count;
#endif
static Thread invoke_thread;
readonly Dictionary<string, Tuple<FieldSpec, FieldInfo>> fields;
Type base_class;
bool inited;
int startup_files;
readonly CompilerContext ctx;
readonly ModuleContainer module;
readonly ReflectionImporter importer;
readonly CompilationSourceFile source_file;
int? listener_id;
public Evaluator (CompilerContext ctx)
{
this.ctx = ctx;
module = new ModuleContainer (ctx);
module.Evaluator = this;
source_file = new CompilationSourceFile (module, null);
module.AddTypeContainer (source_file);
startup_files = ctx.SourceFiles.Count;
// FIXME: Importer needs this assembly for internalsvisibleto
module.SetDeclaringAssembly (new AssemblyDefinitionDynamic (module, "evaluator"));
importer = new ReflectionImporter (module, ctx.BuiltinTypes);
InteractiveBaseClass = typeof (InteractiveBase);
fields = new Dictionary<string, Tuple<FieldSpec, FieldInfo>> ();
}
void Init ()
{
var loader = new DynamicLoader (importer, ctx);
CompilerCallableEntryPoint.Reset ();
RootContext.ToplevelTypes = module;
//var startup_files = new List<string> ();
//foreach (CompilationUnit file in Location.SourceFiles)
// startup_files.Add (file.Path);
loader.LoadReferences (module);
ctx.BuiltinTypes.CheckDefinitions (module);
module.InitializePredefinedTypes ();
inited = true;
}
void ParseStartupFiles ()
{
Driver d = new Driver (ctx);
Location.Initialize (ctx.SourceFiles);
var parser_session = new ParserSession ();
for (int i = 0; i < startup_files; ++i) {
var sf = ctx.SourceFiles [i];
d.Parse (sf, module, parser_session, ctx.Report);
}
}
void Reset ()
{
CompilerCallableEntryPoint.PartialReset ();
Location.Reset ();
Location.Initialize (ctx.SourceFiles);
}
/// <summary>
/// When set evaluator will automatically wait on Task of async methods. When not
/// set it's called responsibility to handle Task execution
/// </summary>
public bool WaitOnTask { get; set; }
/// <summary>
/// If true, turns type expressions into valid expressions
/// and calls the describe method on it
/// </summary>
public bool DescribeTypeExpressions;
/// <summary>
/// Whether the evaluator will use terse syntax, and the semicolons at the end are optional
/// </summary>
public bool Terse = true;
/// <summary>
/// The base class for the classes that host the user generated code
/// </summary>
/// <remarks>
///
/// This is the base class that will host the code
/// executed by the Evaluator. By default
/// this is the Mono.CSharp.InteractiveBase class
/// which is useful for interactive use.
///
/// By changing this property you can control the
/// base class and the static members that are
/// available to your evaluated code.
/// </remarks>
public Type InteractiveBaseClass {
get {
return base_class;
}
set {
base_class = value;
if (value != null && typeof (InteractiveBase).IsAssignableFrom (value))
InteractiveBase.Evaluator = this;
}
}
/// <summary>
/// Interrupts the evaluation of an expression executing in Evaluate.
/// </summary>
/// <remarks>
/// Use this method to interrupt long-running invocations.
/// </remarks>
public void Interrupt ()
{
if (!inited || !invoking)
return;
if (invoke_thread != null) {
#if MONO_FEATURE_THREAD_ABORT
invoke_thread.Abort ();
#else
invoke_thread.Interrupt ();
#endif
}
}
/// <summary>
/// Compiles the input string and returns a delegate that represents the compiled code.
/// </summary>
/// <remarks>
///
/// Compiles the input string as a C# expression or
/// statement, unlike the Evaluate method, the
/// resulting delegate can be invoked multiple times
/// without incurring in the compilation overhead.
///
/// If the return value of this function is null,
/// this indicates that the parsing was complete.
/// If the return value is a string it indicates
/// that the input string was partial and that the
/// invoking code should provide more code before
/// the code can be successfully compiled.
///
/// If you know that you will always get full expressions or
/// statements and do not care about partial input, you can use
/// the other Compile overload.
///
/// On success, in addition to returning null, the
/// compiled parameter will be set to the delegate
/// that can be invoked to execute the code.
///
/// </remarks>
public string Compile (string input, out CompiledMethod compiled)
{
if (input == null || input.Length == 0){
compiled = null;
return null;
}
lock (evaluator_lock){
if (!inited) {
Init ();
ParseStartupFiles ();
} else {
ctx.Report.Printer.Reset ();
}
bool partial_input;
CSharpParser parser = ParseString (ParseMode.Silent, input, out partial_input);
// Terse mode, try to provide the trailing semicolon automatically.
if (parser == null && Terse && partial_input){
bool ignore;
// check if the source would compile with a block, if so, we should not
// add the semicolon.
var needs_block = ParseString (ParseMode.Silent, input + "{}", out ignore) != null;
if (!needs_block)
parser = ParseString (ParseMode.Silent, input + ";", out ignore);
}
if (parser == null){
compiled = null;
if (partial_input)
return input;
ParseString (ParseMode.ReportErrors, input, out partial_input);
return null;
}
Class parser_result = parser.InteractiveResult;
compiled = CompileBlock (parser_result, parser.undo, ctx.Report);
return null;
}
}
/// <summary>
/// Compiles the input string and returns a delegate that represents the compiled code.
/// </summary>
/// <remarks>
///
/// Compiles the input string as a C# expression or
/// statement, unlike the Evaluate method, the
/// resulting delegate can be invoked multiple times
/// without incurring in the compilation overhead.
///
/// This method can only deal with fully formed input
/// strings and does not provide a completion mechanism.
/// If you must deal with partial input (for example for
/// interactive use) use the other overload.
///
/// On success, a delegate is returned that can be used
/// to invoke the method.
///
/// </remarks>
public CompiledMethod Compile (string input)
{
CompiledMethod compiled;
// Ignore partial inputs
if (Compile (input, out compiled) != null){
// Error, the input was partial.
return null;
}
// Either null (on error) or the compiled method.
return compiled;
}
static MethodInfo listener_proxy_value;
internal void EmitValueChangedCallback (EmitContext ec, string name, TypeSpec type, Location loc)
{
if (listener_id == null)
listener_id = ListenerProxy.Register (ModificationListener);
if (listener_proxy_value == null)
listener_proxy_value = typeof (ListenerProxy).GetMethod ("ValueChanged");
#if STATIC
throw new NotSupportedException ();
#else
// object value, int row, int col, string name, int listenerId
if (type.IsStructOrEnum)
ec.Emit (OpCodes.Box, type);
ec.EmitInt (loc.Row);
ec.EmitInt (loc.Column);
ec.Emit (OpCodes.Ldstr, name);
ec.EmitInt (listener_id.Value);
ec.Emit (OpCodes.Call, listener_proxy_value);
#endif
}
/// <summary>
/// Evaluates and expression or statement and returns any result values.
/// </summary>
/// <remarks>
/// Evaluates the input string as a C# expression or
/// statement. If the input string is an expression
/// the result will be stored in the result variable
/// and the result_set variable will be set to true.
///
/// It is necessary to use the result/result_set
/// pair to identify when a result was set (for
/// example, execution of user-provided input can be
/// an expression, a statement or others, and
/// result_set would only be set if the input was an
/// expression.
///
/// If the return value of this function is null,
/// this indicates that the parsing was complete.
/// If the return value is a string, it indicates
/// that the input is partial and that the user
/// should provide an updated string.
/// </remarks>
public string Evaluate (string input, out object result, out bool result_set)
{
CompiledMethod compiled;
result_set = false;
result = null;
input = Compile (input, out compiled);
if (input != null)
return input;
if (compiled == null)
return null;
//
// The code execution does not need to keep the compiler lock
//
object retval = typeof (QuitValue);
try {
invoke_thread = System.Threading.Thread.CurrentThread;
invoking = true;
compiled (ref retval);
#if MONO_FEATURE_THREAD_ABORT
} catch (ThreadAbortException e){
Thread.ResetAbort ();
Console.WriteLine ("Interrupted!\n{0}", e);
#else
} catch (ThreadInterruptedException e) {
Console.WriteLine ("Interrupted!\n{0}", e);
#endif
} finally {
invoking = false;
if (listener_id != null) {
ListenerProxy.Unregister (listener_id.Value);
listener_id = null;
}
}
//
// We use a reference to a compiler type, in this case
// Driver as a flag to indicate that this was a statement
//
if (!ReferenceEquals (retval, typeof (QuitValue))) {
result_set = true;
result = retval;
}
return null;
}
public string [] GetCompletions (string input, out string prefix)
{
prefix = "";
if (input == null || input.Length == 0)
return null;
lock (evaluator_lock){
if (!inited)
Init ();
bool partial_input;
CSharpParser parser = ParseString (ParseMode.GetCompletions, input, out partial_input);
if (parser == null){
return null;
}
Class host = parser.InteractiveResult;
var base_class_imported = importer.ImportType (base_class);
var baseclass_list = new List<FullNamedExpression> (1) {
new TypeExpression (base_class_imported, host.Location)
};
host.SetBaseTypes (baseclass_list);
var access = AssemblyBuilderAccess.RunAndCollect;
var a = new AssemblyDefinitionDynamic (module, "completions");
a.Create (AppDomain.CurrentDomain, access);
module.SetDeclaringAssembly (a);
// Need to setup MemberCache
host.CreateContainer ();
// Need to setup base type
host.DefineContainer ();
var method = host.Members[0] as Method;
BlockContext bc = new BlockContext (method, method.Block, ctx.BuiltinTypes.Void);
try {
method.Block.Resolve (bc, method);
} catch (CompletionResult cr) {
prefix = cr.BaseText;
return cr.Result;
}
}
return null;
}
/// <summary>
/// Executes the given expression or statement.
/// </summary>
/// <remarks>
/// Executes the provided statement, returns true
/// on success, false on parsing errors. Exceptions
/// might be thrown by the called code.
/// </remarks>
public bool Run (string statement)
{
object result;
bool result_set;
return Evaluate (statement, out result, out result_set) == null;
}
/// <summary>
/// Evaluates and expression or statement and returns the result.
/// </summary>
/// <remarks>
/// Evaluates the input string as a C# expression or
/// statement and returns the value.
///
/// This method will throw an exception if there is a syntax error,
/// of if the provided input is not an expression but a statement.
/// </remarks>
public object Evaluate (string input)
{
object result;
bool result_set;
string r = Evaluate (input, out result, out result_set);
if (r != null)
throw new ArgumentException ("Syntax error on input: partial input");
if (result_set == false)
throw new ArgumentException ("The expression failed to resolve");
return result;
}
/// <summary>
/// Experimental!
/// </summary>
public ValueModificationHandler ModificationListener { get; set; }
enum InputKind {
EOF,
StatementOrExpression,
CompilationUnit,
Error
}
//
// Deambiguates the input string to determine if we
// want to process a statement or if we want to
// process a compilation unit.
//
// This is done using a top-down predictive parser,
// since the yacc/jay parser can not deambiguage this
// without more than one lookahead token. There are very
// few ambiguities.
//
InputKind ToplevelOrStatement (SeekableStreamReader seekable)
{
Tokenizer tokenizer = new Tokenizer (seekable, source_file, new ParserSession (), ctx.Report);
// Prefer contextual block keywords over identifiers
tokenizer.parsing_block++;
int t = tokenizer.token ();
switch (t){
case Token.EOF:
return InputKind.EOF;
// These are toplevels
case Token.EXTERN:
case Token.OPEN_BRACKET:
case Token.OPEN_BRACKET_EXPR:
case Token.ABSTRACT:
case Token.CLASS:
case Token.ENUM:
case Token.INTERFACE:
case Token.INTERNAL:
case Token.NAMESPACE:
case Token.PRIVATE:
case Token.PROTECTED:
case Token.PUBLIC:
case Token.SEALED:
case Token.STATIC:
case Token.STRUCT:
return InputKind.CompilationUnit;
// Definitely expression
case Token.FIXED:
case Token.BOOL:
case Token.BYTE:
case Token.CHAR:
case Token.DECIMAL:
case Token.DOUBLE:
case Token.FLOAT:
case Token.INT:
case Token.LONG:
case Token.NEW:
case Token.OBJECT:
case Token.SBYTE:
case Token.SHORT:
case Token.STRING:
case Token.UINT:
case Token.ULONG:
return InputKind.StatementOrExpression;
// These need deambiguation help
case Token.USING:
t = tokenizer.token ();
if (t == Token.EOF)
return InputKind.EOF;
if (t == Token.IDENTIFIER || t == Token.STATIC)
return InputKind.CompilationUnit;
return InputKind.StatementOrExpression;
// Distinguish between:
// delegate opt_anonymous_method_signature block
// delegate type
case Token.DELEGATE:
t = tokenizer.token ();
if (t == Token.EOF)
return InputKind.EOF;
if (t == Token.OPEN_PARENS || t == Token.OPEN_BRACE)
return InputKind.StatementOrExpression;
return InputKind.CompilationUnit;
// Distinguih between:
// unsafe block
// unsafe as modifier of a type declaration
case Token.UNSAFE:
t = tokenizer.token ();
if (t == Token.EOF)
return InputKind.EOF;
if (t == Token.OPEN_PARENS)
return InputKind.StatementOrExpression;
return InputKind.CompilationUnit;
// These are errors: we list explicitly what we had
// from the grammar, ERROR and then everything else
case Token.READONLY:
case Token.OVERRIDE:
case Token.ERROR:
return InputKind.Error;
// This catches everything else allowed by
// expressions. We could add one-by-one use cases
// if needed.
default:
return InputKind.StatementOrExpression;
}
}
//
// Parses the string @input and returns a CSharpParser if succeeful.
//
// if @silent is set to true then no errors are
// reported to the user. This is used to do various calls to the
// parser and check if the expression is parsable.
//
// @partial_input: if @silent is true, then it returns whether the
// parsed expression was partial, and more data is needed
//
CSharpParser ParseString (ParseMode mode, string input, out bool partial_input)
{
partial_input = false;
Reset ();
var enc = ctx.Settings.Encoding;
var s = new MemoryStream (enc.GetBytes (input));
SeekableStreamReader seekable = new SeekableStreamReader (s, enc);
InputKind kind = ToplevelOrStatement (seekable);
if (kind == InputKind.Error){
if (mode == ParseMode.ReportErrors)
ctx.Report.Error (-25, "Detection Parsing Error");
partial_input = false;
return null;
}
if (kind == InputKind.EOF){
if (mode == ParseMode.ReportErrors)
Console.Error.WriteLine ("Internal error: EOF condition should have been detected in a previous call with silent=true");
partial_input = true;
return null;
}
seekable.Position = 0;
source_file.DeclarationFound = false;
CSharpParser parser = new CSharpParser (seekable, source_file, new ParserSession ());
if (kind == InputKind.StatementOrExpression){
parser.Lexer.putback_char = Tokenizer.EvalStatementParserCharacter;
parser.Lexer.parsing_block++;
ctx.Settings.StatementMode = true;
} else {
parser.Lexer.putback_char = Tokenizer.EvalCompilationUnitParserCharacter;
ctx.Settings.StatementMode = false;
}
if (mode == ParseMode.GetCompletions)
parser.Lexer.CompleteOnEOF = true;
ReportPrinter old_printer = null;
if ((mode == ParseMode.Silent || mode == ParseMode.GetCompletions))
old_printer = ctx.Report.SetPrinter (new StreamReportPrinter (TextWriter.Null));
try {
parser.parse ();
} finally {
if (ctx.Report.Errors != 0){
if (mode != ParseMode.ReportErrors && parser.UnexpectedEOF)
partial_input = true;
if (parser.undo != null)
parser.undo.ExecuteUndo ();
parser = null;
}
if (old_printer != null)
ctx.Report.SetPrinter (old_printer);
}
return parser;
}
CompiledMethod CompileBlock (Class host, Undo undo, Report Report)
{
#if STATIC
throw new NotSupportedException ();
#else
string current_debug_name = "eval-" + count + ".dll";
++count;
AssemblyDefinitionDynamic assembly;
AssemblyBuilderAccess access;
if (Environment.GetEnvironmentVariable ("SAVE") != null) {
access = AssemblyBuilderAccess.RunAndSave;
assembly = new AssemblyDefinitionDynamic (module, current_debug_name, current_debug_name);
assembly.Importer = importer;
} else {
access = AssemblyBuilderAccess.RunAndCollect;
assembly = new AssemblyDefinitionDynamic (module, current_debug_name);
}
assembly.Create (AppDomain.CurrentDomain, access);
Method expression_method;
if (host != null) {
var base_class_imported = importer.ImportType (base_class);
var baseclass_list = new List<FullNamedExpression> (1) {
new TypeExpression (base_class_imported, host.Location)
};
host.SetBaseTypes (baseclass_list);
expression_method = (Method) host.Members[0];
if ((expression_method.ModFlags & Modifiers.ASYNC) != 0) {
//
// Host method is async. When WaitOnTask is set we wrap it with wait
//
// void AsyncWait (ref object $retval) {
// $retval = Host();
// ((Task)$retval).Wait(); // When WaitOnTask is set
// }
//
var p = new ParametersCompiled (
new Parameter (new TypeExpression (module.Compiler.BuiltinTypes.Object, Location.Null), "$retval", Parameter.Modifier.REF, null, Location.Null)
);
var method = new Method(host, new TypeExpression(module.Compiler.BuiltinTypes.Void, Location.Null),
Modifiers.PUBLIC | Modifiers.STATIC, new MemberName("AsyncWait"), p, null);
method.Block = new ToplevelBlock(method.Compiler, p, Location.Null);
method.Block.AddStatement(new StatementExpression (new SimpleAssign(
new SimpleName(p [0].Name, Location.Null),
new Invocation(new SimpleName(expression_method.MemberName.Name, Location.Null), new Arguments(0)),
Location.Null), Location.Null));
if (WaitOnTask) {
var task = new Cast (expression_method.TypeExpression, new SimpleName (p [0].Name, Location.Null), Location.Null);
method.Block.AddStatement (new StatementExpression (new Invocation (
new MemberAccess (task, "Wait", Location.Null),
new Arguments (0)), Location.Null));
}
host.AddMember(method);
expression_method = method;
}
host.CreateContainer();
host.DefineContainer();
host.Define();
} else {
expression_method = null;
}
module.CreateContainer ();
// Disable module and source file re-definition checks
module.EnableRedefinition ();
source_file.EnableRedefinition ();
module.Define ();
if (Report.Errors != 0){
if (undo != null)
undo.ExecuteUndo ();
return null;
}
if (host != null){
host.PrepareEmit ();
host.EmitContainer ();
}
module.EmitContainer ();
if (Report.Errors != 0){
if (undo != null)
undo.ExecuteUndo ();
return null;
}
module.CloseContainerEarlyForReflectionEmit ();
module.CloseContainer ();
if (host != null)
host.CloseContainer ();
if (access == AssemblyBuilderAccess.RunAndSave)
assembly.Save ();
if (host == null)
return null;
//
// Unlike Mono, .NET requires that the MethodInfo is fetched, it cant
// work from MethodBuilders. Retarded, I know.
//
var tt = assembly.Builder.GetType (host.TypeBuilder.Name);
var mi = tt.GetMethod (expression_method.MemberName.Name);
//
// We need to then go from FieldBuilder to FieldInfo
// or reflection gets confused (it basically gets confused, and variables override each
// other).
//
foreach (var member in host.Members) {
var field = member as Field;
if (field == null)
continue;
var fi = tt.GetField (field.Name);
Tuple<FieldSpec, FieldInfo> old;
// If a previous value was set, nullify it, so that we do
// not leak memory
if (fields.TryGetValue (field.Name, out old)) {
if (old.Item1.MemberType.IsStruct) {
//
// TODO: Clear fields for structs
//
} else {
try {
old.Item2.SetValue (null, null);
} catch {
}
}
}
fields[field.Name] = Tuple.Create (field.Spec, fi);
}
return (CompiledMethod) System.Delegate.CreateDelegate (typeof (CompiledMethod), mi);
#endif
}
/// <summary>
/// A sentinel value used to indicate that no value was
/// was set by the compiled function. This is used to
/// differentiate between a function not returning a
/// value and null.
/// </summary>
internal static class QuitValue { }
internal Tuple<FieldSpec, FieldInfo> LookupField (string name)
{
Tuple<FieldSpec, FieldInfo> fi;
fields.TryGetValue (name, out fi);
return fi;
}
static string Quote (string s)
{
if (s.IndexOf ('"') != -1)
s = s.Replace ("\"", "\\\"");
return "\"" + s + "\"";
}
public string GetUsing ()
{
if (source_file == null || source_file.Usings == null)
return string.Empty;
StringBuilder sb = new StringBuilder ();
// TODO:
//foreach (object x in ns.using_alias_list)
// sb.AppendFormat ("using {0};\n", x);
foreach (var ue in source_file.Usings) {
if (ue.Alias != null || ue.ResolvedExpression == null)
continue;
sb.AppendFormat("using {0};", ue.ToString ());
sb.Append (Environment.NewLine);
}
return sb.ToString ();
}
internal List<string> GetUsingList ()
{
var res = new List<string> ();
if (source_file == null || source_file.Usings == null)
return res;
foreach (var ue in source_file.Usings)
{
if (ue.Alias != null || ue.ResolvedExpression == null)
continue;
res.Add (ue.NamespaceExpression.Name);
}
return res;
}
internal string [] GetVarNames ()
{
lock (evaluator_lock){
return new List<string> (fields.Keys).ToArray ();
}
}
public string GetVars ()
{
lock (evaluator_lock){
StringBuilder sb = new StringBuilder ();
foreach (var de in fields){
var fi = LookupField (de.Key);
object value;
try {
value = fi.Item2.GetValue (null);
if (value is string)
value = Quote ((string)value);
} catch {
value = "<error reading value>";
}
sb.AppendFormat ("{0} {1} = {2}", fi.Item1.MemberType.GetSignatureForError (), de.Key, value);
sb.AppendLine ();
}
return sb.ToString ();
}
}
/// <summary>
/// Loads the given assembly and exposes the API to the user.
/// </summary>
public void LoadAssembly (string file)
{
var loader = new DynamicLoader (importer, ctx);
var assembly = loader.LoadAssemblyFile (file, false);
if (assembly == null)
return;
lock (evaluator_lock){
importer.ImportAssembly (assembly, module.GlobalRootNamespace);
}
}
/// <summary>
/// Exposes the API of the given assembly to the Evaluator
/// </summary>
public void ReferenceAssembly (Assembly a)
{
lock (evaluator_lock){
importer.ImportAssembly (a, module.GlobalRootNamespace);
}
}
public void ImportTypes (bool importExtensionTypes, params Type[] types) {
#if !STATIC
importer.ImportTypes (types, module.GlobalRootNamespace, importExtensionTypes);
#endif
}
}
/// <summary>
/// A delegate that can be used to invoke the
/// compiled expression or statement.
/// </summary>
/// <remarks>
/// Since the Compile methods will compile
/// statements and expressions into the same
/// delegate, you can tell if a value was returned
/// by checking whether the returned value is of type
/// NoValueSet.
/// </remarks>
public delegate void CompiledMethod (ref object retvalue);
/// <summary>
/// The default base class for every interaction line
/// </summary>
/// <remarks>
/// The expressions and statements behave as if they were
/// a static method of this class. The InteractiveBase class
/// contains a number of useful methods, but can be overwritten
/// by setting the InteractiveBaseType property in the Evaluator
/// </remarks>
public class InteractiveBase {
/// <summary>
/// Determines where the standard output of methods in this class will go.
/// </summary>
public static TextWriter Output = Console.Out;
/// <summary>
/// Determines where the standard error of methods in this class will go.
/// </summary>
public static TextWriter Error = Console.Error;
/// <summary>
/// The primary prompt used for interactive use.
/// </summary>
public static string Prompt = "csharp> ";
/// <summary>
/// The secondary prompt used for interactive use (used when
/// an expression is incomplete).
/// </summary>
public static string ContinuationPrompt = " > ";
/// <summary>
/// Used to signal that the user has invoked the `quit' statement.
/// </summary>
public static bool QuitRequested;
public static Evaluator Evaluator;
/// <summary>
/// Shows all the variables defined so far.
/// </summary>
static public void ShowVars ()
{
Output.Write (Evaluator.GetVars ());
Output.Flush ();
}
/// <summary>
/// Displays the using statements in effect at this point.
/// </summary>
static public void ShowUsing ()
{
Output.Write (Evaluator.GetUsing ());
Output.Flush ();
}
/// <summary>
/// Times the execution of the given delegate
/// </summary>
static public TimeSpan Time (Action a)
{
DateTime start = DateTime.Now;
a ();
return DateTime.Now - start;
}
/// <summary>
/// Loads the assemblies from a package
/// </summary>
/// <remarks>
/// Loads the assemblies from a package. This is equivalent
/// to passing the -pkg: command line flag to the C# compiler
/// on the command line.
/// </remarks>
static public void LoadPackage (string pkg)
{
if (pkg == null){
Error.WriteLine ("Invalid package specified");
return;
}
string pkgout = Driver.GetPackageFlags (pkg, null);
string [] xargs = pkgout.Trim (new Char [] {' ', '\n', '\r', '\t'}).
Split (new Char [] { ' ', '\t'});
foreach (string s in xargs){
if (s.StartsWith ("-r:") || s.StartsWith ("/r:") || s.StartsWith ("/reference:")){
string lib = s.Substring (s.IndexOf (':')+1);
Evaluator.LoadAssembly (lib);
continue;
}
}
}
/// <summary>
/// Loads the assembly
/// </summary>
/// <remarks>
/// Loads the specified assembly and makes its types
/// available to the evaluator. This is equivalent
/// to passing the -pkg: command line flag to the C#
/// compiler on the command line.
/// </remarks>
static public void LoadAssembly (string assembly)
{
Evaluator.LoadAssembly (assembly);
}
static public void print (object obj)
{
Output.WriteLine (obj);
}
static public void print (string fmt, params object [] args)
{
Output.WriteLine (fmt, args);
}
/// <summary>
/// Returns a list of available static methods.
/// </summary>
static public string help {
get {
return "Static methods:\n" +
" Describe (object); - Describes the object's type\n" +
" LoadPackage (package); - Loads the given Package (like -pkg:FILE)\n" +
" LoadAssembly (assembly); - Loads the given assembly (like -r:ASSEMBLY)\n" +
" ShowVars (); - Shows defined local variables.\n" +
" ShowUsing (); - Show active using declarations.\n" +
" Prompt - The prompt used by the C# shell\n" +
" ContinuationPrompt - The prompt for partial input\n" +
" Time (() => { }); - Times the specified code\n" +
" print (obj); - Shorthand for Console.WriteLine\n" +
" quit; - You'll never believe it - this quits the repl!\n" +
" help; - This help text\n";
}
}
/// <summary>
/// Indicates to the read-eval-print-loop that the interaction should be finished.
/// </summary>
static public object quit {
get {
QuitRequested = true;
// To avoid print null at the exit
return typeof (Evaluator.QuitValue);
}
}
/// <summary>
/// Same as quit - useful in script scenerios
/// </summary>
static public void Quit () {
QuitRequested = true;
}
#if !MOBILE
/// <summary>
/// Describes an object or a type.
/// </summary>
/// <remarks>
/// This method will show a textual representation
/// of the object's type. If the object is a
/// System.Type it renders the type directly,
/// otherwise it renders the type returned by
/// invoking GetType on the object.
/// </remarks>
static public string Describe (object x)
{
if (x == null)
return "<null>";
var type = x as Type ?? x.GetType ();
StringWriter sw = new StringWriter ();
new Outline (type, sw, true, false, false).OutlineType ();
return sw.ToString ();
}
#endif
}
class InteractiveMethod : Method
{
public InteractiveMethod(TypeDefinition parent, FullNamedExpression returnType, Modifiers mod, ParametersCompiled parameters)
: base(parent, returnType, mod, new MemberName("Host"), parameters, null)
{
}
public void ChangeToAsync ()
{
ModFlags |= Modifiers.ASYNC;
ModFlags &= ~Modifiers.UNSAFE;
type_expr = new TypeExpression(Module.PredefinedTypes.Task.TypeSpec, Location);
parameters = ParametersCompiled.EmptyReadOnlyParameters;
}
public override string GetSignatureForError()
{
return "InteractiveHost";
}
}
class HoistedEvaluatorVariable : HoistedVariable
{
public HoistedEvaluatorVariable (Field field)
: base (null, field)
{
}
protected override FieldExpr GetFieldExpression (EmitContext ec)
{
return new FieldExpr (field, field.Location);
}
}
/// <summary>
/// A class used to assign values if the source expression is not void
///
/// Used by the interactive shell to allow it to call this code to set
/// the return value for an invocation.
/// </summary>
class OptionalAssign : SimpleAssign {
public OptionalAssign (Expression s, Location loc)
: base (null, s, loc)
{
}
public override Location StartLocation {
get {
return Location.Null;
}
}
protected override Expression DoResolve (ResolveContext ec)
{
Expression clone = source.Clone (new CloneContext ());
clone = clone.Resolve (ec);
if (clone == null)
return null;
//
// A useful feature for the REPL: if we can resolve the expression
// as a type, Describe the type;
//
if (ec.Module.Evaluator.DescribeTypeExpressions && !(ec.CurrentAnonymousMethod is AsyncInitializer)) {
var old_printer = ec.Report.SetPrinter (new SessionReportPrinter ());
Expression tclone;
try {
// Note: clone context cannot be shared otherwise block mapping would leak
tclone = source.Clone (new CloneContext ());
tclone = tclone.Resolve (ec, ResolveFlags.Type);
if (ec.Report.Errors > 0)
tclone = null;
} finally {
ec.Report.SetPrinter (old_printer);
}
if (tclone is TypeExpr) {
Arguments args = new Arguments (1);
args.Add (new Argument (new TypeOf ((TypeExpr) clone, Location)));
return new Invocation (new SimpleName ("Describe", Location), args).Resolve (ec);
}
}
// This means its really a statement.
if (clone.Type.Kind == MemberKind.Void || clone is DynamicInvocation || clone is Assign) {
return clone;
}
source = clone;
var host = (Method) ec.MemberContext.CurrentMemberDefinition;
if (host.ParameterInfo.IsEmpty) {
eclass = ExprClass.Value;
type = InternalType.FakeInternalType;
return this;
}
target = new SimpleName (host.ParameterInfo[0].Name, Location);
return base.DoResolve (ec);
}
public override void EmitStatement(EmitContext ec)
{
if (target == null) {
source.Emit (ec);
return;
}
base.EmitStatement(ec);
}
}
public class Undo
{
List<Action> undo_actions;
public void AddTypeContainer (TypeContainer current_container, TypeDefinition tc)
{
if (current_container == tc){
Console.Error.WriteLine ("Internal error: inserting container into itself");
return;
}
if (undo_actions == null)
undo_actions = new List<Action> ();
if (current_container.Containers != null)
{
var existing = current_container.Containers.FirstOrDefault (l => l.MemberName.Basename == tc.MemberName.Basename);
if (existing != null) {
current_container.RemoveContainer (existing);
undo_actions.Add (() => current_container.AddTypeContainer (existing));
}
}
undo_actions.Add (() => current_container.RemoveContainer (tc));
}
public void ExecuteUndo ()
{
if (undo_actions == null)
return;
foreach (var p in undo_actions){
p ();
}
undo_actions = null;
}
}
static class ListenerProxy
{
static readonly Dictionary<int, ValueModificationHandler> listeners = new Dictionary<int, ValueModificationHandler> ();
static int counter;
public static int Register (ValueModificationHandler listener)
{
lock (listeners) {
var id = counter++;
listeners.Add (id, listener);
return id;
}
}
public static void Unregister (int listenerId)
{
lock (listeners) {
listeners.Remove (listenerId);
}
}
public static void ValueChanged (object value, int row, int col, string name, int listenerId)
{
ValueModificationHandler action;
lock (listeners) {
if (!listeners.TryGetValue (listenerId, out action))
return;
}
action (name, row, col, value);
}
}
}