Rubberduck: Parse error on mutiple `WithEvents` vars

[wqweto]

Grammar chokes on this

Private WithEvents a As VB.Form, WithEvents b As VB.Form

Btw, it just says Parse Error on the toolbar. Where can I see the actual error?

[Vogel612]

The actual error message will be in the logfiles. Assuming this code compiles, we'd need to look at how WithEvents is treated in the grammar.

https://github.com/rubberduck-vba/Rubberduck/blob/87f612bc3b15fd0d7b0a321b6afc19749b001a29/Rubberduck.Parsing/Grammar/VBAParser.g4#L552-L554

The relevant grammar section is visible above. Quick, untested and unverified patch suggestion:

- variableStmt : (DIM | STATIC | visibility) whiteSpace (WITHEVENTS whiteSpace)? variableListStmt;
+ variableStmt : (DIM | STATIC | visibility) whiteSpace variableListStmt;
- variableListStmt : variableSubStmt (whiteSpace? COMMA whiteSpace? variableSubStmt)*;
+ variableListStmt : (WITHEVENTS whiteSpace)? variableSubStmt (whiteSpace? COMMA whiteSpace? (WITHEVENTS whiteSpace)? variableSubStmt)*;

This would move the WITHEVENTS from the variableStmt to the variableListStmt. One could argue that it should instead belong to variableSubStmt. I have not consulted the spec for this.

nb that this change will most likely necessitate resolver changes to correctly flag the variables as "with events"

[MDoerner]

Regarding, seeing the parser error(s), there should be a little red error icon right next to the refresh button stating _Parser Error_. When you click it, a window with the parser error(s) will open.

[comintern]

The spec covers these in 5.2.3.1 Module Variable Declaration Lists

module-variable-declaration-list = (withevents-variable-dcl / variable-dcl)
*( "," (withevents-variable-dcl / variable-dcl) )

Our grammar doesn't make a distinction between variable declarations in modules and procedure bodies (and we're already parsing non-compilable declarations inside procedures) but this syntax is clearly defined as legal.

Based on how module-variable-declaration-list is defined, I'd be more inclined to say that it belongs to variableSubStmt instead of variableListStmt though:

variableStmt : (DIM | STATIC | visibility) whiteSpace variableListStmt;
variableListStmt : variableSubStmt (whiteSpace? COMMA whiteSpace? variableSubStmt)*;
variableSubStmt : (WITHEVENTS whiteSpace)? identifier (whiteSpace? LPAREN whiteSpace? (subscripts whiteSpace?)? RPAREN)? (whiteSpace asTypeClause)?;

[wqweto]

there should be a little red error icon right next to the refresh button stating Parser Error. When you click it, a window with the parser error(s) will open.

Oh, I see I'm missing the icons here and the button next to Refresh/Parse Error is not apparent

Probably something with my installation (I'm not filing a bug here:-))

[MDoerner]

Hm, that the icon does not appear might actually be a bug. The system for the buttons works a bit different in the VB6 editor compared to the VBE. So, we might have missed to implement that the button appears.

[mansellan]

It's #3952.