print OUT $_; # print end hook!      }    }  }  # everything went well!  close (IN);  close (OUT);  rename ($copy_file_name_tmp, $copy_file_name);}################################################################ Visit_Copy: visit the <copy> tags and weave the code into the# source file. In particular, open the source file specified# in the file-source tag. Search for the start hook and# copy until the end hook is reached.###############################################################sub Visit_Copy{  my ($copy_tag, $copy_file_name, $default_module_name, $prefix_path) = @_;  # Check if a file name has been specified  my $dest_file_tag = $copy_tag->getElementsByTagName ('source');  if (! $dest_file_tag)  {    print "Error: <copy-from-source> does not have the <file> tag..";    print "aborting \n";    exit 1;  }  if ($dest_file_tag->getLength != 1)  {    print "Assertion Error: A <copy-from-source> element can have only \           one <source> tag from which to copy elements";    exit (1);  }  my $dest_file_name = $dest_file_tag->item(0)->getFirstChild->getNodeValue;  #Check if the file exists and one is able to access it  $dest_file_name = $prefix_path . "/" . $default_module_name . "/" . $dest_file_name;  open (DEST, "<". $dest_file_name) ||   die "cannot open $dest_file_name \n Wrong <file> tag within <copy-from-source> exiting" ;  # check for the start and end tags within the target file where  # one needs to start copying from  my $start_tag = $copy_tag->getElementsByTagName ('copy-hook-start');  my $end_tag   = $copy_tag->getElementsByTagName ('copy-hook-end');  if (! $start_tag || ! $end_tag)  {    print "Assertion Error: A <copy> element should have a \           <copy-hook-start> tag and <copy-hook-end> tag \n";    exit (1);  }  # Get the <dest-hook> tag that indicates the destination where the  # code between the start and end tags will be placed.  my $dest_hook_tag   = $copy_tag->getElementsByTagName ('dest-hook');  if (! $dest_hook_tag)  {    print "Assertion Error: <copy-from-source> should have a <dest-hook> \           tag that dictates where in the source file the code should be \           placed. \n";    exit (1);  }  # Remove any starting and trailing white spaces  chomp ($dest_hook_tag);  # We have everything we need! Do the copy  my $start_tag_name = $start_tag->item(0)->getFirstChild->getNodeValue;  my $end_tag_name   = $end_tag->item(0)->getFirstChild->getNodeValue;  my $dest_tag_name  = $dest_hook_tag->item(0)->getFirstChild->getNodeValue;  # First we add the FOCUS prepend tags  $start_tag_name = $FOCUS_PREPEND_TAG . $start_tag_name;  $end_tag_name   = $FOCUS_PREPEND_TAG . $end_tag_name;  $dest_tag_name  = $FOCUS_PREPEND_TAG . $dest_tag_name;  # Step 1: Iterate over the target file till the  # dest-hook is found in that file  my $copy_file_name_tmp = $copy_file_name . "tmp";  open (OUT, ">". $copy_file_name_tmp) ||    die "cannot open temporary file for modying file:" . $copy_file_name;  open (IN, "<" . $copy_file_name) ||    die "cannot open file $copy_file_name specified in the <file> tag \n";  my $dest_tag_found = 0; #check if tag matched  foreach my $line (<IN>)  {    if ($line =~ /$dest_tag_name/)    { $dest_tag_found = 1; print OUT $line; last; }    print OUT $line;  }  close (IN);  # If we reached the end of file before finding the tag!  if (! $dest_tag_found)  {    print "\n Error: <dest-hook> tag missing in file .. aborting \n";    close (DEST);    close (IN);    close (OUT);    unlink ($copy_file_name_tmp);    exit (1);  }  # Step 2: Now look in the destination file and look for the hooks  # where one needs to copy. There could be multiple places where the  # hook can be present. E.g.  # .......  # //@@ COPY_START_HOOK  # ....  # ....  # //@@ COPY_END_HOOK  # ....  # ....  # //@@ COPY_START_HOOK  # ....  # ....  # //@@ COPY_END_HOOK  # Handle this case  my $line_matched = 0;  my $start_copying = 0; # initially do not copy  foreach my $line (<DEST>)  {    # Check if the line matches the start tag    if ($line =~/$start_tag_name/)    {      $line_matched += 1;      $start_copying = 1;    }    else    {      # Check if the line matches the end tag      if ($line =~/$end_tag_name/)      {        # check if the start tag matched!        if (! $line_matched)        {          print "Assertion error: <copy-hook-end> tag misplaced with \                 the <copy-hoook-source> \n";          close (DEST);          close (IN);          close (OUT);          unlink ($copy_file_name_tmp);          exit (1);        }        # decrement the count for nested tags        $line_matched -= 1;        if (! $line_matched )          { $start_copying = 0; }      }      else      {        # Print out the line        if ($start_copying)          { print OUT $line; }      }    }  }  # At the end of this loop line_matched should be 0  if ($line_matched)  {    print "Error: in $dest_file_name, number of <copy-hook-source> tags \           did not match the number of <copy-hook-end> tags. Reverting \           changes. \n";    close (DEST);    close (IN);    close (OUT);    unlink ($copy_file_name_tmp);    exit (1);  }  # Step 3: Now copy data after the tag in the original file onto the destination  # file.  open (IN, "<" . $copy_file_name) ||    die "cannot open file $copy_file_name specified in the <file> tag \n";  $dest_tag_found = 0; #used as a flag  foreach my $line (<IN>)  {    if ($dest_tag_found)    { print OUT $line; }    # If the hook is found, then don't write the hook onto OUT    # as it would have been written earlier    if (! $dest_tag_found &&        $line =~ /$dest_tag_name/)      { $dest_tag_found = 1; }  }  # Normal exit path  close (IN);  close (OUT);  close (DEST);  # Rename the tmp file to the file modified  rename ($copy_file_name_tmp, $copy_file_name);}################################################################## commit_files: A procedure to commit all the copy files that# were specialized back to the orginal files.#################################################################sub commit_files{  my ($path_name, $output_path_name, @files) = @_;  # iterate over the file_name_list  foreach my $file (@files)  {    # <file name="....">    my $file_name = $file->getAttribute('name');    # output_path == input_path then do an in place    # substitution.    if ($output_path_name eq $path_name)    {      rename ($path_name . "/" . $file_name . "copy",              $path_name . "/" . $file_name);    }    else    {      # Check if the path_name exists. The path name      # corresponds to a directory. So create it if it does      # not exist.      if (! -d $output_path_name)      {        #@@? Need to revert the *copy files?        mkpath ($output_path_name, 0, 0744) ||          die "cannot create $output_path_name: commit files failed! \n";      }      # move the specialized file to the output directory      rename ($path_name . "/" . $file_name . "copy",              $output_path_name . "/" . $file_name);    }  }}#### Main ######################################################### Specialize_Component# procedure to execute the transformations specified in the# specialization file##################################################################sub Specialize_Components{  # Get the command line arguments  my ($prefix_path, $spl_file, $output_prefix) = @_;  my $parser = XML::DOM::Parser->new();  my $doc = $parser->parsefile($spl_file);  # Check if the prefix path ends with a / or not  # if it does not then manually add the / to it  my $last = substr ($prefix_path, -1);  if ($last ne "/")  { $prefix_path = $prefix_path . "/"; }  # Entry Point: <transform> element  foreach my $transform ($doc->getElementsByTagName('transform'))  {    # <module tags>    foreach my $module ($transform->getElementsByTagName('module'))    {      # Complete path name to the module      my $module_name = $module->getAttribute('name');      my $path_name = $prefix_path . $module_name;      # <file tags>      my @files = $module->getElementsByTagName('file');      foreach my $file (@files)      {	# <file name="....">	my $file_name = $file->getAttribute('name');	# Rather than modifying the files directly, make a local	# copy of the files and then transform them and commit	# if there is a file called foo we make a file foo_copy	my $file_path_copy = $path_name . "/" . $file_name . "copy";	my $file_path_name = $path_name . "/" . $file_name;	copy ($file_path_name, $file_path_copy);	# Diagnostic comment	print "Instrumenting $file_name ..........";        # <comment> ... </comment>        my @comment_list = $file->getElementsByTagName ('comment');        foreach my $comment (@comment_list)        { Visit_Comment ($comment, $file_path_copy); }        # <copy-from-source> ... </copy-from-source>        my @copy_from_source_files =          $file->getElementsByTagName ('copy-from-source');        foreach my $copy_from_source (@copy_from_source_files)        {          Visit_Copy ($copy_from_source,                      $file_path_copy,                      $module_name,                      $prefix_path);        }	# <remove> ... </remove>	my @remove_list = $file->getElementsByTagName ('remove');        foreach my $remove (@remove_list)	{ Visit_Remove ($remove, $file_path_copy); }	# <substitute ... </substitute>	my @substitute_list = $file->getElementsByTagName ('substitute');	foreach my $substitute (@substitute_list)	{ Visit_Substitute ($substitute, $file_path_copy); }	# <add> <hook> ...... </hook> <add>	my @add_list = $file->getElementsByTagName ('add');	foreach my $add (@add_list)	{ Visit_Add ($add, $file_path_copy); }	# Everything went well.. Print success	print " [done] \n";      }    }    # At this point all the specializations in all the modules have    # succeeded. It is at this point that we need to commit the    # specializations in each of the modules. That is move the temporary    # file that we created to the main file that was specialized.    # This also means that we need another loop and do the same thing    # as above....    # <module tags>    foreach my $module ($transform->getElementsByTagName('module'))    {      # Complete path name to the module      my $module_name = $module->getAttribute('name');      my $path_name = $prefix_path . $module_name;      # Output path name: append output_prefix to the      # current module name. Append "/" to create a      # directory like /foo/bar/baz/      my $output_path = $output_prefix . "/" . $module_name;      # <file tags>      my @files = $module->getElementsByTagName('file');      # commit the files      commit_files ($path_name, $output_path, @files);    }  }}##### Requiured for a module####1;