#!/usr/bin/perl

# $Id: convert_swig 3762 2014-12-04 19:48:35Z alin $

use FindBin qw($Bin);
use strict ;
use Getopt::Long;
use Pod::Usage;
use Pod::Text;
use Text::Balanced qw ( extract_bracketed );
use lib "$Bin/pm" ;
use File::Basename ;
use Cwd 'abs_path' ;
use gte ;
use get_headers ;
use trick_version ;
use Digest::MD5 qw(md5_hex) ;

##
## ================================================================================
## Program: convert_swig
##
## The purpose of convert_swig is to create SWIG interface files for the given
## C/C++ header file (usually S_source.hh) and each of the header files that it
## (recursively) includes. SWIG (Simplified Wrapper and Interface Generator) is
## an interface compiler that connects programs written in C and C++ with scripting
## languagues such as Perl and Python.
##

my $usage="
Name:
    convert_swig - Convert a C/C++ header file into a SWIG interface file.
                   SWIG (Simplified Wrapper and Interface Generator) is an
                   interface compiler that connects programs written in C
                   and C++ with scripting languagues such as Perl and Python.

Options:
    -h, --help
            display this help and exit
    -s, --stl
            Allow convert_swig to process STLs
    -o, --outfile  <OUT_FILE>
            provide a name for the generated SWIG interface file which
            is usually denoted with a special .i or .swg suffix

Usage:
    convert_swig [-o <OUT_FILE>] <IN_FILE>

Examples:
    % convert_swig -o swig/Ball.i include/Ball.hh
    % convert_swig -o swig_src/S_source.i S_source.hh
" ;


my ($in_file , $out_file ) ;
my $help = '';  # option variable with default value (false)
my $stls = 0;  # option variable with default value (false)

my ( @include_paths, @include_dirs , @defines) ;
my ( @swig_exclude_dirs) ;
my %sim ;
my %out_of_date ;
my ($version, $thread, $year) ;
my %icg_no ;
my %skipped_files ;
my %processed_templates ;

my $typedef_def = qr/typedef\s+                            # the word typedef
               (?:[_A-Za-z][\s\w]*\s*)                     # resolved type
               (?:[_A-Za-z]\w*)                            # new type
               \s*;                                        # semicolon
             /sx ;

my $typedef_enum_def = qr/typedef\s+enum\s*                # the words typedef enum
               (?:\s+[_A-Za-z]\w*)?\s*                     # optional name
               {(?:\s*\d+\s*)*                             # opening brace and possible comments
               (?:.*?}\s*                                  # everything to closing brace
               [\w,\s\*]*\s*;)                             # enum name and ;
             /sx ;

my $typedef_struct  = qr/typedef\s+(?:struct|union)\s*     # the words typedef struct|union
               (?:\s+[_A-Za-z]\w*)?\s*                     # optional name
               {                                           # opening brace
             /sx ;
my $namespace_def = qr/namespace\s*                        # keyword namespace
             (?:\s+[_A-Za-z]\w*)                           # class name
            /sx ;
my $class_def   = qr/(?:class|struct)\s*                   # keyword class or struct
               (?:\s+[_A-Za-z]\w*)\s*                      # class name
               (?:\{|:(?!\:))                              # { or punctuator :
             /sx ;
my $template_def   = qr/template\s*                        # keyword template
            <[^>]+>\s*                                     # template parameters
            class\s*[_A-Za-z]\w*\s*                        # keyword class and class name
               /sx ;
my $template_var_def  = qr/(?:\:\:)?[_A-Za-z][:\w]*\s*     # template name
            <[\w\s\*,:<>]*>\s*                             # template parameters
            [_A-Za-z]\w*\s*;                               # var name ;
               /sx ;

# This list is the list of all STL types to ignore.
my %all_stl_names = qw(vector 1 list 1 deque 1 set 1 multiset 1 map 1 multimap 1 hash_set 1
     hash_multiset 1 hash_map 1 hash_multimap 1 stack 1 queue 1 priority_queue 1 bitset 1 auto_ptr 1
     std::vector 1 std::list 1 std::deque 1 std::set 1 std::multiset 1 std::map 1 std::multimap 1 std::hash_set 1
     std::hash_multiset 1 std::hash_map 1 std::hash_multimap 1 std::stack 1 std::queue 1 std::priority_queue 1
     std::bitset 1 std::auto_ptr 1 pair 1 std::pair 1 std::tr1::shared_ptr 1) ;

# This is a partial list of STL types to ignore.  We do not ignore vector, map, list if we allow STLs
my %stl_names = qw(deque 1 set 1 multiset 1 multimap 1 hash_set 1
     hash_multiset 1 hash_map 1 hash_multimap 1 stack 1 queue 1 priority_queue 1 bitset 1 auto_ptr 1
     std::deque 1 std::set 1 std::multiset 1 std::multimap 1 std::hash_set 1
     std::hash_multiset 1 std::hash_map 1 std::hash_multimap 1 std::stack 1 std::queue 1 std::priority_queue 1
     std::bitset 1 std::auto_ptr 1 pair 1 std::pair 1 std::tr1::shared_ptr 1) ;

Getopt::Long::Configure ("bundling");
GetOptions ( "outfile|o=s" => \$out_file ,
             "stl|s" => sub { $stls = 1 } ,
             'help|h' => \$help ) or usage() ;

if ( $help ) {
    usage() ;
}

($version, $thread) = get_trick_version() ;
($year) = $version =~ /^(\d+)/ ;

@include_paths = $ENV{"TRICK_CFLAGS"} =~ /(-I\s*\S+)/g ; # get include paths from TRICK_CFLAGS
@include_dirs = $ENV{"TRICK_CFLAGS"} =~ /-I\s*(\S+)/g ; # get include paths from TRICK_CFLAGS
@swig_exclude_dirs = split /:/ , $ENV{"TRICK_SWIG_EXCLUDE"} ;
if ( scalar @swig_exclude_dirs == 0 ) {
    @swig_exclude_dirs = split /:/ , $ENV{"TRICK_ICG_EXCLUDE"} ;
}
push @include_paths , ("-I".$ENV{"TRICK_HOME"}."/trick_source" , "-I../include") ;
@defines = $ENV{"TRICK_CFLAGS"} =~ /(-D\S+)/g ;       # get defines from TRICK_CFLAGS
if ( $ENV{"TRICK_CFLAGS"} !~ /DTRICK_VER=/ ) {
    push @defines , "-DTRICK_VER=$year" ;
}
#(my $cc = gte("TRICK_CC")) =~ s/\n// ;
# Use the c preporcessor directly
my $cc ;
my $system_type = `uname -s` ;
chomp $system_type ;
if ( $system_type eq "Darwin" ) {
    $cc = "/usr/bin/llvm-gcc -E" ;
} else {
    $cc = "/usr/bin/cpp" ;
}

($in_file) = (grep !/^-/ , @ARGV) ;

## The list of header files to be processed is usually produced by the script
## make_swig_makefile.pm, as it's creating Makefile_swig. This list is stored in
## the file ".S_library_swig". So, if .S_library_swig exists, we can just open and read it.
##

my ($s_library_swig) = ".S_library_swig" ;

if ( -e $s_library_swig ) {
    open FILE_LIST, $s_library_swig ;
    while ( <FILE_LIST> ) {
        chomp ;
        $sim{final_all_includes}{$_} = 1 ;
    }
} else {

## Otherwise we need to process S_source.hh to produce the list of header files.
##
## Specifically, we want to generate  SWIG interfaces for those header files that are:
## 1) actual dependencies of S_source.hh, GIVEN THE CURRENT environment and
## 2) not excluded from ICG processing ( by ICG_NO or ICG_EXCLUDE).
##
## The header files that are actually included are the dependencies we care
## about. Keep in mind that the pre-processor and the current ENVIRONMENT
## may cause some headers to be conditionally included or excluded. We only
## want to generate SWIG interfaces for headers that are ACTUALLY included.
##
## Whereas the pre-processor can (using the gcc -MM option) generate a list
## of dependencies that satisfy 1) (above), it can't handle that ICG exclusions.
## And, whereas the function get_headers() can generate a list of dependences
## which are flagged if they contain ICG_NO, it doesn't handle conditional includes.
##
## So, the strategy that we employ is to generate and then find the
## intersection of both lists. Then we eliminate those that are in 1)
## $TRICK_HOME/trick_source, or 2) flagged as containing ICG_NO  or 3) are
## in ICG_EXCLUDE'd directories.
##
## First, create a list headers using the GCC with the -MM option. GCC will
## handle conditional inclusion.
##

    # list of files to process does not exist.  Process S_source.hh to create one.
    my ($s_source_full_path) = abs_path("S_source.hh") ;
    open FILE_LIST, "$cc -MM -DSWIG @include_paths @defines $in_file |" ;
    my $dir ;
    $dir = dirname($s_source_full_path) ;
    while ( <FILE_LIST> ) {
        next if ( /^#/ or /^\s+\\/ ) ;
        my $word ;
        foreach $word ( split ) {
            next if ( $word eq "\\" or $word =~ /o:/ ) ;
            if ( $word !~ /^\// and $dir ne "\/" ) {
                $word = "$dir/$word" ;
            }
            $word = abs_path(dirname($word)) . "/" . basename($word) ;
            # filter out system headers that are missed by the compiler -MM flag
            next if ( $word =~ /^\/usr\/include/) ;
            next if ( $word =~ /$ENV{TRICK_HOME}\/trick_source\//) ;

            #print "gcc found $word\n" ;
            $sim{gcc_all_includes}{$word} = 1 ;
            #$sim{mod_date}{$word} = (stat $word)[9] ;
        }
    }

## Second, create a list where the files are flagged if they contain ICG_NO.
##

    get_headers(\%sim, $s_source_full_path) ;
    if ( open ICGNOFOUND , (".icg_no_found") ) {
        while ( <ICGNOFOUND> ) {
           chomp ;
           $icg_no{$_} = 1 ;
        }
    }

## Then we generate the intersection of the two lists and then eliminate the dependencies that:
## 1) are in $TRICK_HOME/trick_source.
## 2) contain ICG_NO.
## 3) are in ICG_EXCLUDE'd directories.
## to create the final list of header dependencies that we need to convert into SWIG interfaces.
##

    foreach my $k ( keys %{$sim{gcc_all_includes}} ) {
        $sim{final_all_includes}{$k} = 1 if exists $sim{all_includes}{$s_source_full_path} ;
    }

    foreach my $f ( keys %{$sim{final_all_includes}} ) {
        if ( $f =~ /$ENV{TRICK_HOME}\/trick_source/ ) {
            delete $sim{final_all_includes}{$f} ;
        } elsif ( exists $icg_no{$f} ) {
            $skipped_files{$f} = "ICG No found" ;
            delete $sim{final_all_includes}{$f} ;
        } else {
            foreach my $ie ( @swig_exclude_dirs ) {
                # if file location begins with $ie (an IGC exclude dir)
                if ( $f =~ /^\Q$ie/ ) {
                    $skipped_files{$f} = "ICG exclude dir $ie" ;
                    delete $sim{final_all_includes}{$f} ;
                    last ;  # break out of loop
                }
            }
        }
    }
}

## Next we need to determine which of the files do not have up-to-date SWIG files.
## For each header file in final dependency list, if the corresponding SWIG (.i) file
## doesn't exist or the header file is newer than the existing SWIG file, then record
## that a new SWIG file needs needs to be created. The global hash %out_of_date
## represents a list of header files whose corresponding .i files need to be regenerated.
##

foreach my $f ( keys %{$sim{final_all_includes}} ) {
    my ($swig_dir , $base_file , $swig_file ) ;

    $base_file = basename($f) ;
    $base_file =~ s/\.[^\.]+$// ;

    $swig_dir = dirname($f) ;
    $swig_dir =~ s/\/include$//g ;
    $swig_dir .= "/swig" ;
    $swig_file = "$swig_dir/${base_file}.i" ;

    #print "$swig_file\n" ;
    if ( -e $swig_file ) {
        if ( !exists $sim{mod_date}{$f} ) {
            $sim{mod_date}{$f} = (stat $f)[9] ;
        }
        $sim{swig_mod_date}{$f} = (stat $swig_file)[9] ;
        if ( $sim{mod_date}{$f} > $sim{swig_mod_date}{$f} ) {
            $out_of_date{$f} = 1 ;
        }
    } else {
        $out_of_date{$f} = 1 ;
        $sim{swig_mod_date}{$f} = 0 ;
    }
}

if ( scalar keys %out_of_date == 0 ) {
    exit ;
}

foreach ( sort keys %skipped_files ) {
    print  "convert_swig skipping $_ ($skipped_files{$_})\n" ;
}

## Finally, call process_file() to create SWIG interface files for each of the out_of_date headers.
##

process_file(\%sim , abs_path($in_file)) ;

##
## ================================================================================
## process_file
##
## Synopsis
##
## This subroutine processes S_source.h and each of it's requisite header files to
## generate the corresponding SWIG interfaces files.
##
## Parameters
##
## sim_ref
##
## Is this parameter ever used?
##
## in_file
##
## The name of input file, invariably "S_source.hh".
##

sub process_file($$) {

    my ($sim_ref , $in_file) = @_ ;

##  Foreach out_of_date header file, generate a SWIG interface file.

    foreach my $f ( keys %out_of_date ) {

        my @class_names ;
        my ($raw_contents , $contents , $new_contents ) ;
        my ($curr_dir) ;

        next if ( $f =~ /^$ENV{TRICK_HOME}\/trick_source/ ) ;

        # clear the processed templates per each file
        undef %processed_templates ;

##      Read in the entire file contents into raw_contents.
        open IN_FILE, $f ;
        local $/ ;
        $raw_contents = <IN_FILE> ;

        # remove all comments, they can cause all kinds of trouble
        # leave the line continuation character if present in a c++ style comment.
        $raw_contents =~ s/\/\*(?:.*?)\*\/|\/\/(?:.*?)(\\)?(\n)/$1\n/sg ;

##      The init_attr functions cause problems when we try and wrap them with SWIG.
##      We can safely remove them from the header files.
##      Remove the friend init_attr functions that appear in multiline define statements
        $raw_contents =~ s/\\\n\s*friend\s+void\s+init_attr[^(]+\s*\(\s*\)(\s*);?/$1/sg ;
##      Remove the friend init_attr functions outside of multiline define statements
        $raw_contents =~ s/friend\s+void\s+init_attr[^(]+\s*\(\s*\)(\s*);?/$1/sg ;
        #$raw_contents =~ s/friend\s+void\s+init_attr[^;]+;//sg ;
        $raw_contents =~ s/__const/const/sg ;

##      For each of the #includes in the out_of_date header file
##      create a corresponding %import directive.
        foreach (split /^/, $raw_contents) {

            if ( /^(\s*\#\s*include\s+)([^\n]+)/ ) {
                my ( $include ) = $1 ;
                my ( $file_name ) = $2 ;
                if ( $file_name !~ /\</ ) {
                    if ( $file_name !~ /\"sim_services/ and $file_name !~ /\"trick_utils/ )  {
                        my $exclude = 0 ;
                        my $temp_file_name ;

                        $temp_file_name = $file_name ;
                        $temp_file_name =~ s/"//g ;
                        # Check if include file's path begins with dot dot (..)
                        if ( $temp_file_name =~ /^\.\./ ) {
                            # include file location is relative to the input file's path.
                            # Get the absolute path to this include file... use this from now on.
                            $file_name = abs_path(dirname($f)) . "/" . $temp_file_name ;
                            # Re-insert double quotes around include file.
                            $file_name = "\"" . $file_name . "\"" ;
                        } elsif ( $temp_file_name !~ /^\// ) {
                            foreach my $i ( dirname($f) , @include_dirs ) {
                                if ( -e ( "$i/$temp_file_name" ) ) {
                                    $file_name = "\"" . abs_path(dirname("$i/$temp_file_name")) . "/" . basename($temp_file_name) . "\"" ;
                                    last ;
                                }
                            }
                        }

                        foreach my $i ( @swig_exclude_dirs ) {
                            if ( $file_name =~ /^\"\Q$i/ ) {
                                $exclude = 1 ;
                                last ;
                            }
                        }

                        if ( $exclude == 0 ) {
                            if ( $file_name =~ /include\/[^\.]+\.[^\.]+\"/ ) {
                                $file_name =~ s/(.*)include\/([^\.]+\.)[^\.]+\"/${1}swig\/${2}i\"/ ;
                            } elsif ( $file_name =~ /\/([^\.\/]+\.)[^\.]+\"/ ) {
                                $file_name =~ s/\/([^\.\/]+\.)[^\.]+\"/\/swig\/${1}i\"/ ;
                            } else {
                                $file_name =~ s/\.[^\.]+\"/\.i\"/ ;
                            }
                        }
                        $contents .= "\%import $file_name\n" ;
                    } else {
                        $contents .= "\%import(module=\"sim_services\") $file_name\n" ;
                    }
                }
            } else {
                $contents .= $_ ;
            }
        }

##      Process the contents of the out_of_date header file to create the corresponding SWIG interface.

        process_contents( \$contents , \$new_contents , "" , \@class_names ) ;

##      Generate a module name and path for the SWIG interface file.

        my $md5_sum = md5_hex($f) ;

        my ($out_dir) = dirname($f) ;
        $out_file = basename($f) ;

        $out_file =~ s/\.h.*$/\.i/ ;
        $out_dir =~ s/\/include$// ;
        $out_dir .= "/swig" ;

        $out_file = "$out_dir/$out_file" ;

        if ( ! -e $out_dir ) {
            mkdir $out_dir ;
        }

##      Open the SWIG interface file.
##      In the SWIG interface file, write a %module directive that identifies the module.
##      In the SWIG interface file, write a #include directive to include trick_swig interface utilities.
##      In the SWIG interface file, write a #include directive to include the header
##      file to which this interface file corresponds and from which it was derived.
##      In the SWIG interface file, create a SWIG interface for each class declared in the corresponding header file using the
##      %trick_swig_class_typemap() macro. This macro is defined in swig_class_typedef.i, included by trick_swig.i (see above).
##      Write the SWIG interface code (processed header file) and the header file contents.
##      Close the SWIG interface file.

        open OUT, ">$out_file" ;

        print OUT "\%module m$md5_sum\n\n" ;
        print OUT "/* $in_file */\n" ;

        print OUT "#include \"trick_swig/trick_swig.i\"\n\n" ;

        print OUT "
\%{
#include \"$f\"
\%}\n" ;

        print OUT "\n" ;
        my %class_typemap_printed ;
        foreach my $c ( @class_names ) {
            if ( ! exists $class_typemap_printed{$c} ) {
                my $c_ = $c ;
                $c_ =~ s/\:/_/g ;
                print OUT "\%trick_swig_class_typemap($c, $c_)\n" ;
                $class_typemap_printed{$c} = 1 ;
            }
        }
        print OUT "\n$new_contents" ;
        print OUT "$contents\n" ;
        # Add a trick_cast_as macro line for each class parsed in the file.  These lines must appear at the bottom of the
        # file to ensure they are not in a namespace directive and they are after the #define statements they depend on.
        undef %class_typemap_printed ;
        foreach my $c ( @class_names ) {
            if ( ! exists $class_typemap_printed{$c} ) {
                my $c_ = $c ;
                $c_ =~ s/\:/_/g ;
                print OUT "#ifdef TRICK_SWIG_DEFINED_$c_\n" ;
                print OUT "\%trick_cast_as($c, $c_)\n" ;
                print OUT "#endif\n" ;
                $class_typemap_printed{$c} = 1 ;
            }
        }
        close OUT ;

        print "Writing swig_file $out_file\n" ;
    }

}

sub usage() {
    print "$usage\n" ;
    exit ;
}

## ================================================================================
## process_contents
##
## Synopsis
##
## Process header file contents for use in the corresponding SWIG interface file.
##
## Parameters
##
## contents_ref
## (IN) reference to header file contents that are to be converted to a SWIG interface.
##
## new_contents_ref
## (OUT) SWIG interface code, derived from the header file contents.
##
## curr_namespace
## (IN) current namespace.
##
## class_names_ref
## (OUT) reference to an array of class and/or struct names encountered when
## processing the header file contents.
##
## Function Dependencies
##
## process_typedef_struct()
## process_namespace()
## process_class()
##

sub process_contents($$$$) {
    my ( $contents_ref , $new_contents_ref , $curr_namespace , $class_names_ref ) = @_ ;

    while ( $$contents_ref =~ s/^(.*?)(?:($typedef_struct)|
                                    ($template_def)|
                                    ($namespace_def)|
                                    ($class_def))//sx ) {
        my ( $non_var ) = $1 ;
        my ( $typedef_struct_string ) = $2 ;
        my ( $template_string ) = $3 ;
        my ( $namespace_string ) = $4 ;
        my ( $class_string ) = $5 ;

## Handle the case of: non_var
        if ( $non_var ne "" )  {
            $$new_contents_ref .= $non_var ;
        }

##
## Handle the case of: typedef_struct ==> typedef (struct | union ) <name> '{' ...
##
        if ( $typedef_struct_string ne "" )  {
            process_typedef_struct($typedef_struct_string , $contents_ref, $new_contents_ref, $class_names_ref) ;
        }
##
## Handle the case of: template_def ==> template '<' <template-parameters> '>' class <class-name> ...
## This is required so that templated classes do not match the plain class definition.
##
        if ( $template_string ne "" )  {
            $$new_contents_ref .= $template_string ;
            process_template( $contents_ref , $new_contents_ref ) ;
        }
##
## Handle the case of: namespace_def ==> namespace <name>
##
        if ( $namespace_string ne "" )  {
            process_namespace( $namespace_string , $contents_ref , $new_contents_ref , $curr_namespace ,
                               $class_names_ref ) ;
        }
##
##  Handle the case of: class_def ==> ( class | struct ) <class-name> ( '{' | ':' )
##
        if ( $class_string ne "" )  {
            process_class( $class_string , $contents_ref , $new_contents_ref , $curr_namespace ,
                           $class_names_ref ) ;
        }
    }
}

## ================================================================================
## process_template
##
## Synopsis
##
## Process template class definitions.  We want to pass through the contents the template
## without processing. We use extract_bracketed to find the whole template definition
## and copy that into new_contents_ref.
##
## Parameters
##
## contents_ref
## (IN) This is a reference to the remainder of the header file (following the
## above string) to be processed.
##
## new_contents_ref
## (OUT) The SWIG code generated so far.
##
sub process_template($$) {
    my ( $contents_ref , $new_contents_ref ) = @_ ;
    my $extracted ;

    if ( $$contents_ref =~ s/^(\s*;)//s ) {
        $$new_contents_ref .= $1 ;
    } else {
        # grab all of the text including the opening bracket.
        $$contents_ref =~ s/^(.*?\s*\{)//s ;
        $$new_contents_ref .= $1 ;

        # grab the rest of the template
        ($extracted, $$contents_ref) = extract_bracketed( "{" . $$contents_ref , "{}") ;

        # remove added extra opening "brace"
        $extracted =~ s/^\{// ;
        $extracted =~ s/const\s+static/static const/g ;

        $$new_contents_ref .= $extracted ;
    }
}

## ================================================================================
## process_namespace
##
## Synopsis
##
## Process namespaces found in a header file for use in the corresponding SWIG
## interface file.
##
## Parameters
##
## namespace
## (IN) This is a string of the form: B<namespace> B<I<name>>, that was extracted
## from the header file contents. In the contents there should remain the bracketed
## content to which this namespace applies.
##
## contents_ref
## (IN) This is a reference to the remainder of the header file (following the
## above string) to be processed.
##
## new_contents_ref
## (OUT) The SWIG code generated so far.
##
## curr_namespace
## (IN) current namespace.
##
## class_names_ref
## (OUT) reference to an array of class and/or struct names encountered when
## processing the header file contents.
##
## Function Dependencies
##
## extract_bracketed()
## process_contents()
##
sub process_namespace($$$$$) {
    my ( $namespace_string , $contents_ref , $new_contents_ref ,
         $curr_namespace , $class_names_ref ) = @_ ;
    my $extracted ;
    my ($namespace_name) ;

    # Get the name of this namespace and add it to the current namespace
    $namespace_string =~ /namespace\s+([_A-Za-z]\w*)/sx ;
    $namespace_name = $curr_namespace . "$1::" ;
    #print "*** namespace_name = $namespace_name ***\n" ;

    $$new_contents_ref .= $namespace_string ;

    # Extract the contents of the namespace
    ($extracted, $$contents_ref) = extract_bracketed( $$contents_ref , "{}") ;

    # Process the contents of the namespace
    process_contents( \$extracted , $new_contents_ref , $namespace_name , $class_names_ref ) ;

    # Append whatever wasn't matched in process contents to the new file.
    $$new_contents_ref .= $extracted ;
}

## ================================================================================
## process_class
##
## Synopsis
## Process classes declarations found in a header file for use in the corresponding
## SWIG interface file.
##
## Parameters
##
## class_string
## (IN) This is a string of the form: ( class | struct ) <class-name> ( '{' | ':' )
##
## contents_ref
## (IN) This is a reference to the remainder of the header file (following the
## class_string) to be processed.
##
## new_contents_ref
## (OUT) The SWIG code generated so far.
##
## curr_namespace
## (IN) current namespace.
##
## class_names_ref
## (OUT) reference to an array of class and/or struct names encountered when
## processing the header file contents.
##
## <func-depend name="extract_bracketed">

sub process_class($$$$$) {
    my ( $class_string , $contents_ref , $new_contents_ref , $curr_namespace ,
         $class_names_ref ) = @_ ;

    my $extracted ;
    my ($class_name) ;
    my $template_typedefs ;


## Extract the class_name from the class_string
    $class_string =~ /^(?:class|struct)\s+               # keyword class or struct
                      ([_A-Za-z]\w*)                     # class name
                      \s*[\{\:]$
                     /sx or die "Internal error" ;
    $class_name = $1 ;
    $$new_contents_ref .= $class_string ;

    if ( $class_string !~ /\{$/ ) {
        $$contents_ref =~ s/^(.*?\s*\{)//s ;
        $$new_contents_ref .= $1 ;
    }

    ($extracted, $$contents_ref) = extract_bracketed( "{" . $$contents_ref , "{}") ;

    # remove the trailing semicolon because we may append text to the class.
    $$contents_ref =~ s/^\s*;//s ;

    #remove added extra opening "brace"
    $extracted =~ s/^\{// ;

    #print "*** extracted = $extracted ***\n" ;
    #print "*** contents = $$contents_ref ***\n" ;

    # SWIG doesn't like "const static".  Change it to "static const"
    $extracted =~ s/const\s+static/static const/g ;

    # templated variables need to be declared with the SWIG %template directive.
    # This loop looks for any templated variables and creates the %template lines.
    while ( $extracted =~ s/^(.*?)(?:($template_var_def))//sx ) {
        my ( $non_var ) = $1 ;
        my ( $template_var_def_str ) = $2 ;

        if ( $non_var ne "" )  {
            #print "*** non_var = $non_var ***\n" ;
            $$new_contents_ref .= $non_var ;
        }

        if ( $template_var_def_str ne "" )  {
            #print "*** template_var = $template_var_def_str ***\n" ;
            $template_var_def_str =~ /(.*?)([_A-Za-z]\w*)\s*;/s ;
            my ($template_full_type) = $1 ;
            my ($var_name) = $2 ;
            #print "*** var_name = $var_name ***\n" ;
            $$new_contents_ref .= $template_var_def_str ;

            $template_full_type =~ /([_A-Za-z][:\w]*)\s*</ ;
            my ($template_type) = $1 ;
            # ignore some STL types and types that involve std::wstring
            if ( ((  $stls and ! exists $stl_names{$template_type})
               or ( !$stls and ! exists $all_stl_names{$template_type} ))
               and $template_full_type !~ /(std::)?wstring/ ) {

                my ($template_type_no_sp) = $template_full_type ;
                $template_type_no_sp =~ s/\s//g ;
                #print "*** template_type_no_sp = $template_type_no_sp ***\n" ;
                if ( ! exists $processed_templates{$template_type_no_sp} ) {
                    $$new_contents_ref .= "\n#define TRICK_SWIG_TEMPLATE_$class_name${var_name}_template\n" ;
                    $template_typedefs .= "\n#ifdef TRICK_SWIG_TEMPLATE_$class_name${var_name}_template\n" ;
                    $template_typedefs .= "\%template ($class_name${var_name}_template) $template_full_type ;\n" ;
                    $template_typedefs .= "#undef TRICK_SWIG_TEMPLATE_$class_name${var_name}_template\n" ;
                    $template_typedefs .= "#endif\n" ;
                    $processed_templates{$template_type_no_sp} = 1 ;
                }
            }
        }
    }
    #print "*** unprocessed extracted = $extracted ***\n" ;

    push @$class_names_ref , "$curr_namespace$class_name" ;

    # write the class contents and semicolon to ensure any template declarations below are after the semicolon.
    $$new_contents_ref .= $extracted . ";\n" ;
    # write out the templated variable declaration lines found in this class.
    $$new_contents_ref .= $template_typedefs ;

    my $c_ = "$curr_namespace$class_name" ;
    $c_ =~ s/\:/_/g ;
    # Add a #define line that signals that this class has been processed by swig. Classes excluded in #if 0 blocks will
    # not have this #define defined.
    $$new_contents_ref .= "#define TRICK_SWIG_DEFINED_$c_" ;
}

## ================================================================================
## process_typedef_struct
##
## Synopsis
##
## Process a type definition of a struct or union to make it suitable as SWIG
## interface code. Extract the struct (or union) name and bracketed contents from
## the header file text (typedef_struct_string and contents_ref) . Record the
## extracted names in the list referenced by class_names_ref, and then reconsistute
## the type definition, via the new_contents_ref.
##
## Parameters
##
## typedef_struct_string
## (IN) This is a string of the form: 
##     "typedef struct [<name>] {"   OR   "typedef union [<name>] {" </parameter>
##
## contents_ref
## (IN) This is a reference to the remainder of the header file (following the
## above string) to be processed.
##
## new_contents_ref
## (OUT) The SWIG code generated so far.
##
## class_names_ref
## (OUT) reference to an array of class and/or struct names encountered when
## processing the header file contents.
##
sub process_typedef_struct($$$$) {

    my ($typedef_struct_string , $contents_ref, $new_contents_ref , $class_names_ref) = @_ ;

    my $extracted ;
    my ($begin, $tail , $struct_names, @struct_names) ;

    #print "*** typedef_struct_string = $typedef_struct_string ***\n" ;

    $$new_contents_ref .= $typedef_struct_string ;

    $typedef_struct_string =~ s/((?:typedef\s+)?(struct|union)\s*   # the words typedef struct|union
         ([_A-Za-z]\w*)?\s*                                         # optional name
         {)//sx ;
    $begin = $3 ;

    ($extracted, $$contents_ref) = extract_bracketed( "{" . $$contents_ref , "{}") ;
    #print "*** extracted = $extracted ***\n" ;

    #remove added extra opening "brace"
    $extracted =~ s/{// ;

    $$contents_ref =~ s/^(\s*([\w,\s\*]+)?\s*;)//sx ;
    $tail = $1 ;
    $struct_names = $2 ;

    $struct_names =~ s/\s//g ;
    @struct_names = split /,/ , $struct_names ;

    if ( $begin ne "" ) {
        push @$class_names_ref , $begin ;
    }
    foreach my $s ( @struct_names ) {
        if ( $s !~ /\*/ ) {
            push @$class_names_ref , $s ;
        }
    }

    $$new_contents_ref .= $extracted . $tail ;

}

__END__