Bug 3882 – GW: WebCore does not compile using bison 2.0

• Component: New Bugs
• Status: RESOLVED FIXED

[Eric Seidel (no email)]

#define YYMAXDEPTH 0

causes a later warning when compiling the code
(<= comparison with 0 is always true), which breaks the build.

Still investigating solutions.

[Eric Seidel (no email)]

6:46pm] toby: YYINITDEPTH is what the bison author suggested when i emailed
[6:46pm] toby: i.e. #define YYMAXDEPTH YYINITDEPTH

I also asked bdash to try removing the line and seeing if it still compiled under bison 1.3.  He said it did.

I'm not yet sure what #define YYMAXDEPTH 0 was supposed to accomplish.

[Eric Seidel (no email)]

My best understanding is that 
#define YYMAXDEPTH 0
was actually just asking bison to use it's default value (under some previous version of bison).

I think we inherited this line all the way from from initial import from khtml.

http://www.mico.org/pipermail/mico-devel/2003-June/007336.html
aids my suspicion that this is actually just setting the default value.

Attached a fix.

[Eric Seidel (no email)]

bdash confirmed this further for me:

/*  YYMAXDEPTH is the maximum size the stacks can grow to
    (effective only if the built-in stack extension method is used).  */

#if YYMAXDEPTH == 0
#undef YYMAXDEPTH
#endif

#ifndef YYMAXDEPTH
#define YYMAXDEPTH 10000
#endif

used to be generated by bison 1.3 now the 

#if YYMAXDEPTH == 0
#undef YYMAXDEPTH
#endif

is missing from 2.0's generation.

Comparing the generated output you see exactly this:

-#if YYMAXDEPTH == 0
-#undef YYMAXDEPTH
-#endif

[Eric Seidel (no email)]

Created attachment 2844 [details]
A trivial fix for 2.0 compatibility.

[Maciej Stachowiak]

Comment on attachment 2844 [details]
A trivial fix for 2.0 compatibility.

r=me

but just to be on the safe side make sure the layout tests pass.