/* ****************************************************************************

*

* Copyright (c) Microsoft Corporation.

*

* This source code is subject to terms and conditions of the Apache License, Version 2.0. A

* copy of the license can be found in the License.html file at the root of this distribution. If

* you cannot locate the Apache License, Version 2.0, please send an email to

* dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound

* by the terms of the Apache License, Version 2.0.

*

* You must not remove this notice, or any other, from this software.

*

*

* ***************************************************************************/

#if FEATURE_CORE_DLR

using MSAst = System.Linq.Expressions;

#else

using MSAst = Microsoft.Scripting.Ast;

#endif

using System;

using System.Diagnostics;

using System.Threading;

using Microsoft.Scripting;

using Microsoft.Scripting.Generation;

using Microsoft.Scripting.Runtime;

using Microsoft.Scripting.Utils;

using IronPython.Compiler.Ast;

using IronPython.Runtime;

using IronPython.Runtime.Operations;

namespace IronPython.Compiler {

/// <summary>

/// Represents a script code which can be consumed at runtime as-is. This code has

/// no external dependencies and is closed over its scope.

/// </summary>

class RuntimeScriptCode : RunnableScriptCode {

private readonly CodeContext/*!*/ _optimizedContext;

private Func<FunctionCode, object> _optimizedTarget;

private ScriptCode _unoptimizedCode;

public RuntimeScriptCode(PythonAst/*!*/ ast, CodeContext/*!*/ codeContext)

: base(ast) {

Debug.Assert(codeContext.GlobalScope.GetExtension(codeContext.LanguageContext.ContextId) != null);

Debug.Assert(ast.Type == typeof(MSAst.Expression<Func<FunctionCode, object>>));

_optimizedContext = codeContext;

}

public override object Run() {

return InvokeTarget(CreateScope());

}

public override object Run(Scope scope) {

return InvokeTarget(scope);

}

public override FunctionCode GetFunctionCode(bool register) {

EnsureCompiled();

return EnsureFunctionCode(_optimizedTarget, false, register);

}

private object InvokeTarget(Scope scope) {

if (scope == _optimizedContext.GlobalScope && !_optimizedContext.LanguageContext.EnableTracing) {

EnsureCompiled();

Exception e = PythonOps.SaveCurrentException();

var funcCode = EnsureFunctionCode(_optimizedTarget, false, true);

PushFrame(_optimizedContext, funcCode);

try {

if (Ast.CompilerContext.SourceUnit.Kind == SourceCodeKind.Expression) {

return OptimizedEvalWrapper(funcCode);

}

return _optimizedTarget(funcCode);

} finally {

PythonOps.RestoreCurrentException(e);

PopFrame();

}

}

// if we're running against a different scope or we need tracing then re-compile the code.

if (_unoptimizedCode == null) {

// TODO: Copy instead of mutate

((PythonCompilerOptions)Ast.CompilerContext.Options).Optimized = false;

Interlocked.CompareExchange(

ref _unoptimizedCode,

Ast.MakeLookupCode().ToScriptCode(),

null

);

}

// This is a brand new ScriptCode which also handles all appropriate ScriptCode

// things such as pushing a function code or updating the stack trace for

// exec/eval code. Therefore we don't need to do any of that here.

return _unoptimizedCode.Run(scope);

}

private object OptimizedEvalWrapper(FunctionCode funcCode) {

try {

return _optimizedTarget(funcCode);

} catch (Exception e) {

PythonOps.UpdateStackTrace(e, _optimizedContext, Code, 0);

throw;

}

}

public override Scope/*!*/ CreateScope() {

return _optimizedContext.GlobalScope;

}

private void EnsureCompiled() {

if (_optimizedTarget == null) {

Interlocked.CompareExchange(ref _optimizedTarget, Compile(), null);

}

}

private Func<FunctionCode, object>/*!*/ Compile() {

var pco = (PythonCompilerOptions)Ast.CompilerContext.Options;

var pc = (PythonContext)SourceUnit.LanguageContext;

if (pc.ShouldInterpret(pco, SourceUnit)) {

return ((Microsoft.Scripting.Ast.LightExpression<Func<FunctionCode, object>>)Ast.GetLambda()).Compile(pc.Options.CompilationThreshold);

} else {

return ((Microsoft.Scripting.Ast.LightExpression<Func<FunctionCode, object>>)Ast.GetLambda()).ReduceToLambda().Compile(pc.EmitDebugSymbols(SourceUnit));

}

}

}

}