internal override MSAst.Expression Transform(AstGenerator ag, Type type) {
return ag.Get(
type,
SymbolTable.IdToString(_name),
ag.Transform(_target)
);
}
internal override MSAst.Expression Transform(AstGenerator ag, Type type) {
return ag.Get(
type,
_name,
ag.Transform(_target)
);
}
private MSAst.Expression SetMemberOperator(AstGenerator ag, MSAst.Expression right, PythonOperationKind op, MSAst.ParameterExpression temp) {
return ag.Set(
typeof(object),
_name,
temp,
ag.Operation(
typeof(object),
op,
ag.Get(
typeof(object),
_name,
temp
),
right
)
);
}
/// <summary>
/// WithStatement is translated to the DLR AST equivalent to
/// the following Python code snippet (from with statement spec):
///
/// mgr = (EXPR)
/// exit = mgr.__exit__ # Not calling it yet
/// value = mgr.__enter__()
/// exc = True
/// try:
/// VAR = value # Only if "as VAR" is present
/// BLOCK
/// except:
/// # The exceptional case is handled here
/// exc = False
/// if not exit(*sys.exc_info()):
/// raise
/// # The exception is swallowed if exit() returns true
/// finally:
/// # The normal and non-local-goto cases are handled here
/// if exc:
/// exit(None, None, None)
///
/// </summary>
internal override MSAst.Expression Transform(AstGenerator ag) {
MSAst.ParameterExpression lineUpdated = ag.GetTemporary("$lineUpdated_with", typeof(bool));
// Five statements in the result...
MSAst.Expression[] statements = new MSAst.Expression[6];
//******************************************************************
// 1. mgr = (EXPR)
//******************************************************************
MSAst.ParameterExpression manager = ag.GetTemporary("with_manager");
statements[0] = ag.MakeAssignment(
manager,
ag.Transform(_contextManager),
new SourceSpan(Start, _header)
);
//******************************************************************
// 2. exit = mgr.__exit__ # Not calling it yet
//******************************************************************
MSAst.ParameterExpression exit = ag.GetTemporary("with_exit");
statements[1] = ag.MakeAssignment(
exit,
ag.Get(
typeof(object),
"__exit__",
manager
)
);
//******************************************************************
// 3. value = mgr.__enter__()
//******************************************************************
MSAst.ParameterExpression value = ag.GetTemporary("with_value");
statements[2] = ag.AddDebugInfo(
ag.MakeAssignment(
value,
ag.Invoke(
typeof(object),
new CallSignature(0),
ag.Get(
typeof(object),
"__enter__",
manager
)
)
),
new SourceSpan(Start, _header)
);
//******************************************************************
// 4. exc = True
//******************************************************************
MSAst.ParameterExpression exc = ag.GetTemporary("with_exc", typeof(bool));
statements[3] = ag.MakeAssignment(
exc,
AstUtils.Constant(true)
);
//******************************************************************
// 5. The final try statement:
//
// try:
// VAR = value # Only if "as VAR" is present
// BLOCK
// except:
// # The exceptional case is handled here
// exc = False
// if not exit(*sys.exc_info()):
// raise
// # The exception is swallowed if exit() returns true
// finally:
// # The normal and non-local-goto cases are handled here
// if exc:
// exit(None, None, None)
//******************************************************************
MSAst.ParameterExpression exception = ag.GetTemporary("exception", typeof(Exception));
MSAst.ParameterExpression nestedFrames = ag.GetTemporary("$nestedFrames", typeof(List<DynamicStackFrame>));
statements[4] =
// try:
AstUtils.Try(
AstUtils.Try(// try statement body
ag.PushLineUpdated(false, lineUpdated),
_var != null ?
ag.AddDebugInfo(
Ast.Block(
// VAR = value
_var.TransformSet(ag, SourceSpan.None, value, PythonOperationKind.None),
// BLOCK
ag.Transform(_body),
AstUtils.Empty()
),
_body.Span
) :
// BLOCK
ag.Transform(_body) // except:, // try statement location
).Catch(exception,
// Python specific exception handling code
TryStatement.GetTracebackHeader(
ag,
exception,
ag.AddDebugInfo(
Ast.Block(
// exc = False
ag.MakeAssignment(
exc,
AstUtils.Constant(false)
),
Ast.Assign(
nestedFrames,
Ast.Call(AstGenerator.GetHelperMethod("GetAndClearDynamicStackFrames"))
),
// if not exit(*sys.exc_info()):
// raise
AstUtils.IfThen(
ag.Convert(
typeof(bool),
ConversionResultKind.ExplicitCast,
ag.Operation(
typeof(bool),
PythonOperationKind.Not,
MakeExitCall(ag, exit, exception)
)
),
ag.UpdateLineUpdated(true),
Ast.Call(
AstGenerator.GetHelperMethod("SetDynamicStackFrames"),
nestedFrames
),
Ast.Rethrow()
)
),
_body.Span
)
),
Ast.Call(
AstGenerator.GetHelperMethod("SetDynamicStackFrames"),
nestedFrames
),
ag.PopLineUpdated(lineUpdated),
Ast.Empty()
)
// finally:
).Finally(
// if exc:
// exit(None, None, None)
AstUtils.IfThen(
exc,
ag.AddDebugInfo(
Ast.Block(
Ast.Dynamic(
ag.BinderState.Invoke(
new CallSignature(3) // signature doesn't include function
),
typeof(object),
new MSAst.Expression[] {
ag.LocalContext,
exit,
AstUtils.Constant(null),
AstUtils.Constant(null),
AstUtils.Constant(null)
}
),
Ast.Empty()
),
_contextManager.Span
)
)
);
statements[4] = ag.AddDebugInfo(statements[4], Span);
statements[5] = AstUtils.Empty();
return ag.AddDebugInfo(Ast.Block(statements), _body.Span);
}
