NAME

    App::unifdef+ - simplify pre-conditionals in C, Makefile and Kconfig files

SYNOPSIS

        unifdef+ [-D define=val] [-U undifined] ... file

    Run unifdef --help for more options.

DESCRIPTION

    unifdef+ is a script to simplify conditional parts of source files based
    on passed in defines and undefined values.   It simplifies conditions and,
    if resolved will remove any inapplicable parts of the file.   It does not
    simplify any portions of code which do not use any of the passed in macros
    (so it will not simplify an #if TRUE ... #endif clause)   
    
    For C++/C files, it operates on preprocessor conditionals.  For Makefiles 
    it operates on ifeq, ifdef statements, and in Kconfig file, it operates on 
    dependson and if clauses.
    
    For C/C++, it is fully functional, and will simplify multiline statements,
    with whitespace, and comments, and honors the C operator precidence.
    
    For Kconfig files it handles multi-variable, and tristate conditionals,
    and honors the Kconfig operator precidence.  (It also handles comments
    properly)
    
    For Makefile, support is limited to the functions, catination, the 
    $(or ...) $(and ...) and $(strip ...) functions.

 EXAMPLE
 
  C / C++
    
    if you had source file foo.c:
        
        /* FOO.c */
        #if  ( defined(UNDEF1) && defined(UNKNOWN1) ) || \
             !defined DEF1  // resolves to false
            /* block will NOT appear */
        #elif DEF1 <= 3 && UNKNOWN1 > (3 + 2)   // (condition simplifies)
            /* block will appear */
        #elif DEF1 > 3  // condition resolves to false (1 < 3...)
            /* block will NOT appear */
        #else
            /* block will appear, as an else to the unknown */
        #endif
        
    and you ran:
     
        unifdef+ -D DEF1=1 -D DEF2=2 -U UNDEF1 foo.c
     
    it would modify foo.c in place to read:
     
        /* FOO.c */
        #if UNKNOWN1 > (3 + 2)   // (condition simplifies)
            /* block will appear */
        #else
            /* block will appear, as an else to the unknown */
        #endif        

 MAKEFILE
 
     If you had a makefile foo.mak:
     
		/* FOO.mak */
		ifeq ( $(and $(CONFIG_DEF_Y),$(CONFIG_UNKNOWN)), y )
		      # block will will appear, and above
		      # conditional will be simplified
		else ifeq "$(CONFIG_UNDEF)" "y"
		      # block will not appear
		else ifdef CONFIG_DEF_Y
		      # block will appear
		else
		      # block will NOT appear
		endif
         
     and you ran:
     
         unifdef+ -D CONFIG_DEF_Y=y -U CONFIG_UNDEF -I foo.mak
     
     it would read in foo.mak, and output to stdout:
     
		/* FOO.mak */
		ifeq ($(CONFIG_UNKNOWN),y)
		      # block will will appear, and above
		      # conditional will be simplified
		else
		      # block will appear
		endif

KCONFIG
     If you had a kconfig file   Kconfig.foo:
     
        #Kconfig.foo
        
        config FOOBAR
            tristate "Some feature"
            depends on DEF1 && DEF2
            default m if DEF1
            default y if UNDEF1
            help
                 supports multiline help
        
                 including blank lines between help entries
        
        config FOOBARED2
             tristate "Some feature"
             depends on UNDEF1 && DEF2
        
        
        if UNDEF1
             # block removed
        endif
        
    and you ran
    
        unifdef+ -D DEF1=y -D DEF2=m -U UNDEF1 Kconfig.foo
               
    It would modify Kconfig.foo in place, and output:
    
        #Kconfig.foo
        
        config FOOBAR
            tristate "Some feature"
            depends on DEF2
            default m
            help
                 supports multiline help
        
                 including blank lines between help entries 
 
INSTALLATION

    You should install unifdef+ using cpan tools:  cpan code::UnifdefPlus
 
DEPENDENCIES

    perl 5.10 or later.

QUESTIONS

COPYRIGHT

    Copyright 2017 - John Ulvr
 
LICENSE

    This software is licensed under the same terms as Perl.

CREDITS

 CONTRIBUTORS

    Many thanks to Joel Peshkin for helping write this module

 ACKNOWLEDGEMENTS

COMMUNITY

NO WARRANTY

    This software is provided "as-is," without any express or implied
    warranty. In no event shall the author be held liable for any damages
    arising from the use of the software.


