Parse::Readelf::Debug::Line - handle readelf's debug line section with a class
use Parse::Readelf::Debug::Line; my $line_info = new Parse::Readelf::Debug::Line($executable); my $object_id = $line_info->object_id("mocdule.c"); my $file_name = $line_info->file($object_id, $number); my $directory_name = $line_info->directory($object_id, $number); my $path = $line_info->path($object_id, $number); my $object_name = $line_info->object_name($object_id); my $file_count = $line_info->files($object_id); my @files = $line_info->files($object_id); my $directory_count = $line_info->directories($object_id); my @directories = $line_info->directories($object_id); my $path_count = $line_info->paths($object_id); my @paths = $line_info->paths($object_id);
Parse::Readelf::Debug::Line parses the output of readelf --debug-dump=line and stores its interesting details in an object to be available. Normally it's not used directly but by other modules of Parse::Readelf.
readelf --debug-dump=line
Parse::Readelf
Normally an object of this class is constructed with the file name of an object file to be parsed. Upon construction the file is analysed and all relevant information about its debug line section is stored inside of the object. This information can be accessed afterwards using a bunch of getter methods, see "METHODS" for details.
Currently only output for Dwarf version 2 is supported. Please contact the author for other versions and provide some example readelf outputs.
readelf
Nothing is exported by default as it's normally not needed to modify any of the variables declared in the following export groups:
all of the following groups
is the variable holding the command to run readelf to get the information relevant for this module, normally readelf --debug-dump=line.
is the regular expression that recognises the start of the line debug output of readelf.
is the regular expression that recognises the Dwarf version line in a line debug output of readelf. The version number must be an integer number which will (must) be stored in $1.
$1
is the version dependent regular expression that recognises the start of the directory table in line debug output of readelf.
is the version dependent regular expression that recognises the start of the non-empty file name table in line debug output of readelf.
is the version dependent regular expression that recognises the heading line of the file name table in line debug output of readelf. If this must be modified this probably means the parsing will not work correctly!
$line_info = new Parse::Readelf::Debug::Line($file_name);
$line_info1 = new Parse::Readelf::Debug::Line('program'); $line_info2 = new Parse::Readelf::Debug::Line('module.o');
$file_name name of executable or object file
This method parses the output of C<readelf --debug-dump=line> and stores its interesting details internally to be accessed later by getter methods described below.
The method uses all of the variables described above in the L</"EXPORT"> section.
The method returns the blessed Parse::Readelf::Debug::Line object or an exception in case of an error.
$object_id = $line_info->object_id($file_name);
$object_id = $line_info->object_id('module.c');
$file_name name of the source file (without directory)
This method returns the internal object ID of a module when given the name of its source file without directory. This is a non-negative number.
The method returns the object ID or -1 if no matching object was found.
$object_name = $line_info->object_name($object_id);
$object_name = $line_info->object_name(0);
$object_id internal object ID of module
This method is the opposite method of L<|C<object_id>>, it returns the name of the major source file for the given internal object ID of a module.
The method returns the source name or an empty string if no matching object was found.
$file_name = $line_info->file($object_id, $source_number, $relax);
$file_name = $line_info->file(0, 0); $file_name = $line_info->file(0, 0, 1); # Dwarf-4
$object_id internal object ID of module $source_number number of the source $relax optional flag to enable fallback code for object ID
This method returns the file name (without directory) of the source file number C<$source_number> for the given internal object ID of a module. The source number is a positive integer. 1 is the number of the major source file, all others are usually include files. Note that 0 is not used! Newer Dwarf versions don't seem to use different tables for different object IDs and put all sources into one table. The optional flag C<$relax> tells the method to use this one table in those cases.
The method returns the source name or an empty string if no matching source was found in the object.
@file_names = $line_info->files($object_id); $file_count = $line_info->files($object_id);
@file_names = $line_info->files(1); $number_of_files = $line_info->files($object_id);
In list context this method returns a list of all file names (without directory parts) for the given internal object ID of a module. In scalar context it returns how many elements this list would have. As number 1 is the first source number actually used in the internal representation of the list the number returned in scalar context is also the last number you can pass to the L<|C<file>> method described above that returns a valid name (a non empty string). Note also that the empty element 0 is not part of the list returned in list context.
The method returns the list / the count as described above or an empty list / 0 if an unused or invalid object id was given.
$directory = $line_info->directory($object_id, $source_number);
$directory = $line_info->directory(0, 0);
$object_id internal object ID of module $source_number number of the source
This method returns the directory part of the file name of the source file number C<$source_number> for the given internal object ID of a module. The source number is a positive integer. 1 is the number of the major source file, all others are usually include files. Note that 0 is not used!
The method returns the directory name or an empty string if no matching source was found in the object.
@directories = $line_info->directories($object_id); $dir_count = $line_info->directories($object_id);
@directories = $line_info->directories(1); $number_of_dirs = $line_info->directories($object_id);
In list context this method returns a list of the directory parts of all file names for the given internal object ID of a module. As usually several used include files are found in the same directory this list normally will contain duplictes. Those are NOT eliminated. In scalar context it returns how many elements this list would have. As number 1 is the first source number actually used in the internal representation of the list the number returned in scalar context is also the last number you can pass to the L<|C<directory>> method described above that returns a valid name (a non empty string). Note also that the empty element 0 is not part of the list returned in list context.
$file_path = $line_info->path($object_id, $source_number);
$file_path = $line_info->path(0, 0);
This method returns the path (directory plus file name) of the source file number C<$source_number> for the given internal object ID of a module. The source number is a positive integer. 1 is the number of the major source file, all others are usually include files. Note that 0 is not used!
@paths = $line_info->paths($object_id); $path_count = $line_info->paths($object_id);
@paths = $line_info->paths(1); $number_of_paths = $line_info->paths($object_id);
In list context this method returns a list of all paths (directory plus file name) for the given internal object ID of a module. In scalar context it returns how many elements this list would have. As number 1 is the first source number actually used in the internal representation of the list the number returned in scalar context is also the last number you can pass to the L<|C<file>> method described above that returns a valid name (a non empty string). Note also that the empty element 0 is not part of the list returned in list context.
Only Dwarf version 2 is supported. Please contact the author for other versions and provide some example readelf outputs.
This has only be tested in a Unix like environment and uses Unix path syntax in some places.
Parse::Readelf and the readelf man page
Thomas Dorner, <dorner (AT) cpan.org>
Copyright (C) 2007-2013 by Thomas Dorner
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.6.1 or, at your option, any later version of Perl 5 you may have available.
To install Parse::Readelf, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Parse::Readelf
CPAN shell
perl -MCPAN -e shell install Parse::Readelf
For more information on module installation, please visit the detailed CPAN module installation guide.