Top   Types   Functions   Classes   Index   Sources 

Error Code Assignment

Adding Files to Projects
Assigning Error Numbers
Processing of Error Numbers
Pre-Defined Functions
User-Defined Functions
Version Management:
Removing Files from Projects
Multiple Project Files
New Projects
Manually Defined Data Base Directories

Assigning Error Numbers

Error number can be assigned automaticall using the program 'errcodes'. It's syntax very much resembles that of cvs.

When you change a file using 'errcodes', it is wise to commit it into CVS before that. This makes it easy to trace automatic changes.

Adding Files to Projects

Before a file can be processed to add error numbers, it must be part of a project. If you are a user, it is most probable that there is a default project 'default' that is used for all files in the system and that you do not need to know exactly about long project names, so this paragraph will be enough to read for you. Otherwise, also read the paragraph 'New Projects'.

To add files to a project, use:

errcodes add [-project PROJECTNAME] FILE1 FILE2 ... FILEn

If you do not specify '-project PROJECTNAME', the project name 'default' is assumed.

This is what happens when you add a file to a project:


The file will not be assigned with numbers by the 'add' command. Use the 'update' command for this.

You can add a file to several projects, IF YOU DO IT WITH CARE. The 'errcodes' application assures unique numbers inside each project when assigning new numbers. Read the paragraph 'Multiple Project Files' for this.

Assigning Error Numbers

To assign error numbers in files that are part of some project, use the 'update' command:

errcodes update FILE1 FILE2 ... FILEn

Each file will be processed seperately, so the files need not belong to the same project.

If you want to update the whole sub-directory tree, simply use:

errcodes update

This searches for files in the current directory and in sub-directories and updates all files that belong to at least one project.

For up-to-date checks, it is important that the system clock is in sync with the CVS server's clock. If you encounter problems, use the --force option with 'update' command.

Processing of Error Numbers

The errcodes script maintains a data base of parameters of functions that are error numbers. These parameters are automatically assigned and renumbered.

Pre-Defined Functions

The following parameters are recognised and processed by the 'update' and 'add' commands:

The parser tries its best to parse C and C++ files in the correct syntax, including comments, strings, etc. For the given parameter, all spaces and commands are deleted before it is checked, the rest of the source code is left as is. The parser only parses the input file recursively after a token from the above list has been found (so it recognises nested parameters correctly). The remaining part of the file is processed token by token.

'errcodes' changes the given parameter in the following way:

If the parameter is a number:

If the parameter is something list '(X)->number' where X is a C identifier, nothing is changed. This is for using functions from the list above in macros when error numbers are passed as macro args. The identifier is meant to be such a macro arg and the macro should be invoked using the 'err_number()' function call which will then be processed.

Other parameters are not changed but produce a warning.

The usage of err_number() (in C) and ErrNumber() (in C++) are for explicitly having 'errcodes' process numbers that would otherwise not be recognised. You can use this in macros that defined error numbers or when you use a function of the above in a macro and want to pass an error number.

User-Defined Functions

FIXME: continue

Version Management:

CVS version management is a problem that is not yet solved perfectly. 'errcodes' maintains only one data base for a project, therefore, you can simply assign error numbers in branches without conflicting with other branches.

However, when joining branches, conflicts may occur due to differently assigned errors. Currently, it is up to the user to resolve these conflicts by simply deleting one of the conflicting portions of text.


The idea is to re-assign the error numbers of all files of a project (or of several projects). 'errcodes' will process the same parameters as mentioned before and consistently re-assign the numbers.

Re-assignment of numbers is not yet implemented.

Removing Files from Projects

This is not yet implemented.

Multiple Project Files

The problem with multiple project files are collisions of error numbers. E.g. if two files A and B are part of a project X and A and B share error numbers, e.g. there is an err_show_message(...) in A and the corresponding eprintf(...) in B, then it must be ensured that when adding A and B to a project Y, the error numbers are changed consistently.

For this to be done, you must add the files A and B to project Y in the same invocation of the 'errcodes' program, because otherwise the correspondance will be lost:

errcodes add -project Y  A B

Unfortunately, it is quite impossible to do this automatically, so the user has to take care of this.

New Projects

Each file that contains error numbers can be part of several projects. Projects have to be initialised before they can be used. Use 'errcodes init ...' to do this:

errcodes init default

- initialises the project 'default'

Projects names are composed of three components separated by commas.

  1. the CVS root,

  2. the CVS directory,

  3. the project name local to this root.

The first two components define the path to the directory in CVS that 'errcodes' uses to maintain the data base for error numbers. (CVS is always used for this, currently it does not work without). In this directory, 'errcodes' maintains several files that are not interesting in detail to the normal user. For each CVS directory for 'errcodes', several projects can be given.

By default, the CVS root in the current directory is used and the directory 'errcodes' is used for the data base. Make sure this directory does exist in CVS, otherwise you will get an error -- it will not be created automatically in order to prevent errors.

If this is not what you want, e.g., if you often use several CVS roots, read the following paragraph.

Manually Defined Data Base Directories

Each of the three components is searched as an infix in all the three components. To make use of this feature, you must define the CVS base dirs that may be used by 'errcodes'. This can be done in the file '@sysconfdir@errcodes.conf' or in '~.errcodesrc' with the option:


PATH defaults to 'errcodes'.


With this specification, the above specification of a project to initialise, 'default', is an abbreviation for,errcodes,default

Another abbreviations would be:


(Because sub-strings are matched for each component).

A special case occurs of ROOT is '.' in which case the current directory is searched for a CVS sub-directory and the given root is added to the list of data base directories. This is also the default if you do not add any data base directories.


Stoppt die Vorratsdatenspeicherung
November 26th, 2007
Comments? Suggestions? Corrections? You can drop me a line.