/// <summary>
/// Emits the try block and the catch blocks.
/// </summary>
/// <param name="codeGenerator">A code generator.</param>
/// <remarks>
/// <code>
/// try
/// {
/// // guarded code //
/// }
/// catch(E1 $e1)
/// {
/// // E1 //
/// }
/// catch(E2 $e2)
/// {
/// // E2 //
/// }
/// </code>
/// is translated as follows:
/// <code>
/// try
/// {
/// // guarded code //
/// }
/// catch(PhpUserException _e)
/// {
/// PhpObject _o = _e.UserException;
/// if (_o instanceOf E1)
/// {
/// $e1 = _o;
/// // E1 //
/// }
/// else if (_o instanceOf E2)
/// {
/// $e2 = _o;
/// // E2 //
/// }
/// else
/// {
/// throw;
/// }
/// }
/// </code>
/// </remarks>
internal override void Emit(CodeGenerator /*!*/ codeGenerator)
{
Statistics.AST.AddNode("TryStmt");
// emit try block without CLR exception block if possible
if (!HasCatches && !HasFinallyStatements)
{
this.Statements.Emit(codeGenerator);
return;
}
// emit CLR exception block
ILEmitter il = codeGenerator.IL;
codeGenerator.ExceptionBlockNestingLevel++;
// TRY
Label end_label = il.BeginExceptionBlock();
this.Statements.Emit(codeGenerator);
// catches
if (HasCatches)
{
// catch (PHP.Core.ScriptDiedException)
// { throw; }
il.BeginCatchBlock(typeof(PHP.Core.ScriptDiedException));
il.Emit(OpCodes.Rethrow);
// catch (System.Exception ex)
il.BeginCatchBlock(typeof(System.Exception));
// <exception_local> = (DObject) (STACK is PhpUserException) ? ((PhpUserException)STACK).UserException : ClrObject.WrapRealObject(STACK)
Label clrExceptionLabel = il.DefineLabel();
Label wrapEndLabel = il.DefineLabel();
LocalBuilder exception_local = il.GetTemporaryLocal(typeof(DObject));
il.Emit(OpCodes.Dup);
il.Emit(OpCodes.Isinst, typeof(PHP.Core.PhpUserException)); // <STACK> as PhpUserException
il.Emit(OpCodes.Brfalse, clrExceptionLabel);
// if (<STACK> as PhpUserException != null)
{
il.Emit(OpCodes.Ldfld, Fields.PhpUserException_UserException);
il.Emit(OpCodes.Br, wrapEndLabel);
}
// else
il.MarkLabel(clrExceptionLabel);
{
il.Emit(OpCodes.Call, Methods.ClrObject_WrapRealObject);
}
il.MarkLabel(wrapEndLabel);
il.Stloc(exception_local);
// emits all PHP catch-blocks processing into a single CLI catch-block:
foreach (CatchItem c in catches)
{
Label next_catch_label = il.DefineLabel();
// IF (exception <instanceOf> <type>);
c.Emit(codeGenerator, exception_local, end_label, next_catch_label);
// ELSE
il.MarkLabel(next_catch_label);
}
il.ReturnTemporaryLocal(exception_local);
// emits the "else" branch invoked if the exceptions is not catched:
il.Emit(OpCodes.Rethrow);
}
// finally
if (HasFinallyStatements)
{
finallyItem.Emit(codeGenerator);
}
//
il.EndExceptionBlock();
codeGenerator.ExceptionBlockNestingLevel--;
}