TODO #1065

Error handling statement (%1) could not be converted properly. A throw statement was generated instead.

Description

This EWI is generated when an error handling statement is too complex or if it is a pattern that is not supported by the VB6 AI Migrator.

Recommendations

Most occurrences of this EWI will require manual changes to the source code to fix the issue. However, most cases of an error label that is globally called within a function can be replaced by a single try { } catch statement with the addition of return statements where appropriate.

The code example illustrates such an example.

Sample VB6

PublicFunction ErrorHandlingStatement() AsString

Dim ObjD AsInteger

OnErrorGoTo LabelErr

LabelStart:

ObjD = ErrRaisableSub

LabelExit:

ExitFunction

LabelErr:

If ObjD = 1 Then

Resume LabelStart

Else

Resume LabelExit

EndIf

EndFunction

Target VB.NET

PublicFunction ErrorHandlingStatement() AsString

Dim ObjD AsInteger

OnErrorGoTo LabelErr

LabelStart:

ObjD = ErrRaisableSub()

LabelExit:

ExitFunction

LabelErr:

If ObjD = 1 Then

Resume LabelStart

Else

Resume LabelExit

EndIf

EndFunction

Expected VB.NET

One way of changing this error patern to ensure functional equivalence is:

PublicFunction ErrorHandlingStatement() AsString

Dim ObjD AsInteger

Try

ObjD = ErrRaisableSub()

Catch

If ObjD <> 1 Then

Return"FAILED"

EndIf

EndTry

Return"OK"

EndFunction

Target C#

staticpublicstring ErrorHandlingStatement()

{

int ObjD = 0;

//UPGRADE_TODO: (1065) Error handling statement (On Error Goto) could not be converted properly. A throw statement was generated instead.

thrownewException("Migration Exception: 'On Error Goto LabelErr' not supported");

ObjD = ErrRaisableSub();

LabelExit:

return"OK";

LabelErr:

if (ObjD == 1)

{

//UPGRADE_TODO: (1065) Error handling statement (Resume) could not be converted properly. A throw statement was generated instead.

thrownewException("Migration Exception: 'Resume LabelExit' not supported");

}

return"FAILED";

}

Expected C#

One way of changing this error patern to ensure functional equivalence is to do the following changes:

staticpublicstring ErrorHandlingStatement()

{

int ObjD = 0;

try

{

ObjD = ErrRaisableSub();

}

catch (Exception)

{

if (ObjD != 1)

{

return"FAILED";

}

}

return"OK";

}