Re: [Opencxx-users] Throw Clause Fix

[Stefan S. <se...@sy...>]

jal...@st... wrote:
> Hello Everyone again,
> 
> I have fixed the throw clause problem that was in my previous email by 
> changing the body of the method bool Parser::optThrowDecl(Ptree*& throw_decl) 
> in the parser.cc file (for OpenC++ 2.5.12 but each version of OpenC++ has the 
> same implementation for this method).  Here is what I changed this method to:

[...]

Thanks for the bug report, and thanks for trying to fix it !
I don't think your code really solves the problem, though.
Here is my understanding of the problem:

First note that the ptree fragment that results from parsing the declaration
is never used as of now. (Grzegorz: we should add new ptree nodes for this,
shouldn't we ?)
optThrowDecl uses 'rName' in a loop, i.e. it assumes the throw specifier
contains a list of identifiers. That is probably so because in most cases
what you throw is a class, and as non-builtin types are not looked up during
this stage of the parsing, optThrowDecl simply has to look for identifiers.
Now you put a builtin type there, which the lexer reports as a special token,
which the parser doesn't expect (it expects identifiers !). Boom !!

You have replaced the loop involving 'rName' with 'rTempArgList'.
That's a method that parses template arguments, which is probably not what
you thought what it does :-)

Anyways I believe as this wasn't really a problem until now we should just
keep a record of this bug (a good case for a unit test to remind us until
we fix it !) and fix it when we can. That is, I believe, as soon as we
have a symbol lookup mechanism integrated into the parser, and thus we can
look for a 'list of types'.

Makes sense ?

Thanks for your your help !

Stefan