CFD Online Discussion Forums - [Other] Installation issues with flex 2.6.0 and inelegant solution

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Installation issues with flex 2.6.0 and inelegant solution

Issues are caused by the fact that the pre-processor only checks the subminor version of the flex release.

Do this:

% cd $WM_PROJECT_DIR
% find . -name '*.L' -print

Open all of the above in your fav editor (I use jEdit). Change all instances of
#if YY_FLEX_SUBMINOR_VERSION < 34
to
#if YY_FLEX_SUBMINOR_VERSION < 34 && YY_FLEX_SUBMINOR_VERSION > 0

Your code will (hopefully) now compile.

************************************************** *******

NOTE: THIS IS A HORRIBLE HORRIBLE HACK. Use only if you prefer to keep flex 2.6.0+. A proper check needs to know major, minor and subminor numbers (or whatever they are called). Hopefully the future versions will patch this issue.

Quote:

Originally Posted by windscion (Post 578983)

Open all of the above in your fav editor (I use jEdit). Change all instances of
#if YY_FLEX_SUBMINOR_VERSION < 34
to
#if YY_FLEX_SUBMINOR_VERSION < 34 && YY_FLEX_SUBMINOR_VERSION > 0

NOTE: THIS IS A HORRIBLE HORRIBLE HACK. Use only if you prefer to keep flex 2.6.0+. A proper check needs to know major, minor and subminor numbers (or whatever they are called). Hopefully the future versions will patch this issue.

The less horrible hack is to check minor and subminor version, just as you suggested.
The check original seems to have been necessary due to a problem with versions 2.5.4 and 2.5.34, see http://www.openfoam.org/mantisbt/view.php?id=224

Code:

#if YY_FLEX_SUBMINOR_VERSION < 34 && YY_FLEX_MINOR_VERSION < 6

extern "C" int yywrap()

#else

int yyFlexLexer::yywrap()

#endif

{

    return 1;

}

I reported the issue with flex-2.6 (http://www.openfoam.org/mantisbt/view.php?id=1974)
At some point in time, this will affect also non-Arch users, although Ubuntu 16.04 will include flex-2.5.39-8