Re: [Flex-devel] Bug in skeleton processing?

[Joe K. <kr...@ni...>]

Joe Krahn wrote:
> I noticed that the skeleton conditional "%if-tables-serialization" does 
> not push the conditional stack. In the following section from the 
> skeleton source:
> 
> %if-tables-serialization
> #include <sys/types.h>
> #include <netinet/in.h>
> %endif
> 
> The %endif statement here is actually popping an initial 'true' pushed 
> on to the conditional stack before processing started, instead of ending 
> the "%if-tables-serialization" section, which it seems is the actual 
> intention.
> 
> Joe Krahn

Looking into this further, it is definitely a bug, but I have not yet 
looked into how it affects the output.

In addition to "%if-tables-serialization" not pushing onto the 
conditional stack, there is at least one other place where %if/%endif is 
unbalanced. Near line 860 is the following:


     }; /* end struct yyguts_t */
]])

%if-c-only
m4_ifdef( [[M4_YY_NOT_IN_HEADER]],
[[
static int yy_init_globals M4_YY_PARAMS( M4_YY_PROTO_ONLY_ARG );
]])
%endif c-only

%if-reentrant



This section begins already inside of an %if-c-only and %if-reentrant, 
but they are repeated here. Later on, an unbalanced %endif pops an extra 
condition from the stack.

Every time skelout() starts, it pushes an extra TRUE onto the stack. 
This happens at the beginning, after each of the %% insertion sections. 
The only use for that pushed TRUE condition is to allow for an extra 
imbalanced %endif.

I modified "%if-tables-serialization" to push the stack, and took out 
the initial sko_push at the beginning of skelout(). When the 
conditionals are balanced, it works as expected. I have not gone over 
the skeleton file to figure out the side-effects of balancing 
conditionals. I assume it passes all of the tests with the current bugs.

Joe Krahn