using flex files with VC++.net
Author
I''ve been messing around with the idea of writing a scripting system for my engine and I was reading about flex as a lexical analyzer instead of making my own. I understand how everything is working but I was wondering if anybody else has tried to compile the lex.yy.c files created by flex with a vc++.net project. I had one problem which I seemed to fix by creating an artificial function but I also get a linking 2019 error. Any help on how I can fix this would be appreciated. I''ve been stewing over this for the past day now. Thanks.
Mat
Last time I wrote a lexical analyzer, I made a program to spew the state table out to a file... it might be easier if you do it by hand, since Lexs don't get terribly complicated for typical scripting languages (programming languages are really simple for Lexs)
Also, on the parser side of things...
If you're really hard-core, you can use the .v (verbose) file output from yacc and hand-craft your parser .cpp file. I used ParGen once when I was writing a C parser, and I decided that the output .c file from yacc was a bunch of crap, so I wrote another parser that just took the .v intermediate file and wrote a .cpp file (NICE class based, unlike the name-collision-happy stuff that yacc used to spew)
This requires intimate knowledge of LALR or SLR parser logic... but can generate WAY more compact C++ parse tables than yacc does (or even a parse table in a data file to avoid code bloat).
You'll have to write all the code to do shift/reducing (my C parser had 218 reduce cases) manually instead of in the .y file, but you'll have WAY more control over the C++ code and linking issue.
If you want to get that far "under-the-hood", I've got a help-doc I wrote during my Compilers class at college.
[edited by - Nypyren on December 4, 2002 10:36:15 PM]
Also, on the parser side of things...
If you're really hard-core, you can use the .v (verbose) file output from yacc and hand-craft your parser .cpp file. I used ParGen once when I was writing a C parser, and I decided that the output .c file from yacc was a bunch of crap, so I wrote another parser that just took the .v intermediate file and wrote a .cpp file (NICE class based, unlike the name-collision-happy stuff that yacc used to spew)
This requires intimate knowledge of LALR or SLR parser logic... but can generate WAY more compact C++ parse tables than yacc does (or even a parse table in a data file to avoid code bloat).
You'll have to write all the code to do shift/reducing (my C parser had 218 reduce cases) manually instead of in the .y file, but you'll have WAY more control over the C++ code and linking issue.
If you want to get that far "under-the-hood", I've got a help-doc I wrote during my Compilers class at college.
[edited by - Nypyren on December 4, 2002 10:36:15 PM]
Author
Nypyren,
I would like to see that help doc before I decide if I will go through with writing everything myself. You can send it to my e-mail at doodah2001@hotmail.com. Thanks.
Mat
I would like to see that help doc before I decide if I will go through with writing everything myself. You can send it to my e-mail at doodah2001@hotmail.com. Thanks.
Mat
The whole idea behing lex/yacc (flex/bison) is to *save* you time. 
But I remember when I was "hardcore" and would do hand-tuning stuff like that. Turns out life is too short.
Perhaps if the original poster would share the exact error message, we could offer some concrete help. I am using flex/bison with VC++ 6 with no problems...
But I remember when I was "hardcore" and would do hand-tuning stuff like that. Turns out life is too short.
Perhaps if the original poster would share the exact error message, we could offer some concrete help. I am using flex/bison with VC++ 6 with no problems...
Author
Here is the exact error:
LNK2019: unresolved external symbol _main referenced in function _mainCRTStartup.
I have a friend whos been using flex and bison and he said that he didn''t have a problem when he used it with VC++6 either. It has to be something specific with .net but I can''t figure it out. Any help would be appreciated.
LNK2019: unresolved external symbol _main referenced in function _mainCRTStartup.
I have a friend whos been using flex and bison and he said that he didn''t have a problem when he used it with VC++6 either. It has to be something specific with .net but I can''t figure it out. Any help would be appreciated.
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