gperf (3.1)

Browse

Build Log

Usage

This is gperf.info, produced by makeinfo version 5.2 from gperf.texi.

INFO-DIR-SECTION Programming Tools
START-INFO-DIR-ENTRY
* Gperf: (gperf). Perfect Hash Function Generator.
END-INFO-DIR-ENTRY

This file documents the features of the GNU Perfect Hash Function
Generator 3.1.

Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the section entitled "GNU General Public License" is included
exactly as in the original, and provided that the entire resulting
derived work is distributed under the terms of a permission notice
identical to this one.

Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that the section entitled "GNU General Public License"
and this permission notice may be included in translations approved by
the Free Software Foundation instead of in the original English.

File: gperf.info, Node: Top, Next: Copying, Prev: (dir), Up: (dir)

Introduction
************

This manual documents the GNU 'gperf' perfect hash function generator
utility, focusing on its features and how to use them, and how to report
bugs.

* Menu:

* Copying:: GNU General Public License says how you can
copy and share 'gperf'.
* Contributors:: People who have contributed to 'gperf'.
* Motivation:: The purpose of 'gperf'.
* Search Structures:: Static search structures and GNU 'gperf'
* Description:: High-level discussion of how GPERF functions.
* Options:: A description of options to the program.
* Bugs:: Known bugs and limitations with GPERF.
* Projects:: Things still left to do.
* Bibliography:: Material Referenced in this Report.

* Concept Index::

High-Level Description of GNU 'gperf'

* Input Format:: Input Format to 'gperf'
* Output Format:: Output Format for Generated C Code with 'gperf'
* Binary Strings:: Use of NUL bytes
* Controlling Identifiers:: Avoiding collisions of identifiers
* Output Copyright:: The Copyright of the Output.

Input Format to 'gperf'

* Declarations:: Declarations.
* Keywords:: Format for Keyword Entries.
* Functions:: Including Additional C Functions.
* Controls for GNU indent:: Where to place directives for GNU 'indent'.

Declarations

* User-supplied Struct:: Specifying keywords with attributes.
* Gperf Declarations:: Embedding command line options in the input.
* C Code Inclusion:: Including C declarations and definitions.

Invoking 'gperf'

* Input Details:: Options that affect Interpretation of the Input File
* Output Language:: Specifying the Language for the Output Code
* Output Details:: Fine tuning Details in the Output Code
* Algorithmic Details:: Changing the Algorithms employed by 'gperf'
* Verbosity:: Informative Output

File: gperf.info, Node: Copying, Next: Contributors, Prev: Top, Up: Top

GNU GENERAL PUBLIC LICENSE
**************************

Version 3, 29 June 2007

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.

Preamble
========

The GNU General Public License is a free, copyleft license for
software and other kinds of works.

The licenses for most software and other practical works are designed
to take away your freedom to share and change the works. By contrast,
the GNU General Public License is intended to guarantee your freedom to
share and change all versions of a program--to make sure it remains free
software for all its users. We, the Free Software Foundation, use the
GNU General Public License for most of our software; it applies also to
any other work released this way by its authors. You can apply it to
your programs, too.

When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
them if you wish), that you receive source code or can get it if you
want it, that you can change the software or use pieces of it in new
free programs, and that you know you can do these things.

To protect your rights, we need to prevent others from denying you
these rights or asking you to surrender the rights. Therefore, you have
certain responsibilities if you distribute copies of the software, or if
you modify it: responsibilities to respect the freedom of others.

For example, if you distribute copies of such a program, whether
gratis or for a fee, you must pass on to the recipients the same
freedoms that you received. You must make sure that they, too, receive
or can get the source code. And you must show them these terms so they
know their rights.

Developers that use the GNU GPL protect your rights with two steps:
(1) assert copyright on the software, and (2) offer you this License
giving you legal permission to copy, distribute and/or modify it.

For the developers' and authors' protection, the GPL clearly explains
that there is no warranty for this free software. For both users' and
authors' sake, the GPL requires that modified versions be marked as
changed, so that their problems will not be attributed erroneously to
authors of previous versions.

Some devices are designed to deny users access to install or run
modified versions of the software inside them, although the manufacturer
can do so. This is fundamentally incompatible with the aim of
protecting users' freedom to change the software. The systematic
pattern of such abuse occurs in the area of products for individuals to
use, which is precisely where it is most unacceptable. Therefore, we
have designed this version of the GPL to prohibit the practice for those
products. If such problems arise substantially in other domains, we
stand ready to extend this provision to those domains in future versions
of the GPL, as needed to protect the freedom of users.

Finally, every program is threatened constantly by software patents.
States should not allow patents to restrict development and use of
software on general-purpose computers, but in those that do, we wish to
avoid the special danger that patents applied to a free program could
make it effectively proprietary. To prevent this, the GPL assures that
patents cannot be used to render the program non-free.

The precise terms and conditions for copying, distribution and
modification follow.

TERMS AND CONDITIONS
====================

0. Definitions.

"This License" refers to version 3 of the GNU General Public
License.

"Copyright" also means copyright-like laws that apply to other
kinds of works, such as semiconductor masks.

"The Program" refers to any copyrightable work licensed under this
License. Each licensee is addressed as "you". "Licensees" and
"recipients" may be individuals or organizations.

To "modify" a work means to copy from or adapt all or part of the
work in a fashion requiring copyright permission, other than the
making of an exact copy. The resulting work is called a "modified
version" of the earlier work or a work "based on" the earlier work.

A "covered work" means either the unmodified Program or a work
based on the Program.

To "propagate" a work means to do anything with it that, without
permission, would make you directly or secondarily liable for
infringement under applicable copyright law, except executing it on
a computer or modifying a private copy. Propagation includes
copying, distribution (with or without modification), making
available to the public, and in some countries other activities as
well.

To "convey" a work means any kind of propagation that enables other
parties to make or receive copies. Mere interaction with a user
through a computer network, with no transfer of a copy, is not
conveying.

An interactive user interface displays "Appropriate Legal Notices"
to the extent that it includes a convenient and prominently visible
feature that (1) displays an appropriate copyright notice, and (2)
tells the user that there is no warranty for the work (except to
the extent that warranties are provided), that licensees may convey
the work under this License, and how to view a copy of this
License. If the interface presents a list of user commands or
options, such as a menu, a prominent item in the list meets this
criterion.

1. Source Code.

The "source code" for a work means the preferred form of the work
for making modifications to it. "Object code" means any non-source
form of a work.

A "Standard Interface" means an interface that either is an
official standard defined by a recognized standards body, or, in
the case of interfaces specified for a particular programming
language, one that is widely used among developers working in that
language.

The "System Libraries" of an executable work include anything,
other than the work as a whole, that (a) is included in the normal
form of packaging a Major Component, but which is not part of that
Major Component, and (b) serves only to enable use of the work with
that Major Component, or to implement a Standard Interface for
which an implementation is available to the public in source code
form. A "Major Component", in this context, means a major
essential component (kernel, window system, and so on) of the
specific operating system (if any) on which the executable work
runs, or a compiler used to produce the work, or an object code
interpreter used to run it.

The "Corresponding Source" for a work in object code form means all
the source code needed to generate, install, and (for an executable
work) run the object code and to modify the work, including scripts
to control those activities. However, it does not include the
work's System Libraries, or general-purpose tools or generally
available free programs which are used unmodified in performing
those activities but which are not part of the work. For example,
Corresponding Source includes interface definition files associated
with source files for the work, and the source code for shared
libraries and dynamically linked subprograms that the work is
specifically designed to require, such as by intimate data
communication or control flow between those subprograms and other
parts of the work.

The Corresponding Source need not include anything that users can
regenerate automatically from other parts of the Corresponding
Source.

The Corresponding Source for a work in source code form is that
same work.

2. Basic Permissions.

All rights granted under this License are granted for the term of
copyright on the Program, and are irrevocable provided the stated
conditions are met. This License explicitly affirms your unlimited
permission to run the unmodified Program. The output from running
a covered work is covered by this License only if the output, given
its content, constitutes a covered work. This License acknowledges
your rights of fair use or other equivalent, as provided by
copyright law.

You may make, run and propagate covered works that you do not
convey, without conditions so long as your license otherwise
remains in force. You may convey covered works to others for the
sole purpose of having them make modifications exclusively for you,
or provide you with facilities for running those works, provided
that you comply with the terms of this License in conveying all
material for which you do not control copyright. Those thus making
or running the covered works for you must do so exclusively on your
behalf, under your direction and control, on terms that prohibit
them from making any copies of your copyrighted material outside
their relationship with you.

Conveying under any other circumstances is permitted solely under
the conditions stated below. Sublicensing is not allowed; section
10 makes it unnecessary.

3. Protecting Users' Legal Rights From Anti-Circumvention Law.

No covered work shall be deemed part of an effective technological
measure under any applicable law fulfilling obligations under
article 11 of the WIPO copyright treaty adopted on 20 December
1996, or similar laws prohibiting or restricting circumvention of
such measures.

When you convey a covered work, you waive any legal power to forbid
circumvention of technological measures to the extent such
circumvention is effected by exercising rights under this License
with respect to the covered work, and you disclaim any intention to
limit operation or modification of the work as a means of
enforcing, against the work's users, your or third parties' legal
rights to forbid circumvention of technological measures.

4. Conveying Verbatim Copies.

You may convey verbatim copies of the Program's source code as you
receive it, in any medium, provided that you conspicuously and
appropriately publish on each copy an appropriate copyright notice;
keep intact all notices stating that this License and any
non-permissive terms added in accord with section 7 apply to the
code; keep intact all notices of the absence of any warranty; and
give all recipients a copy of this License along with the Program.

You may charge any price or no price for each copy that you convey,
and you may offer support or warranty protection for a fee.

5. Conveying Modified Source Versions.

You may convey a work based on the Program, or the modifications to
produce it from the Program, in the form of source code under the
terms of section 4, provided that you also meet all of these
conditions:

a. The work must carry prominent notices stating that you
modified it, and giving a relevant date.

b. The work must carry prominent notices stating that it is
released under this License and any conditions added under
section 7. This requirement modifies the requirement in
section 4 to "keep intact all notices".

c. You must license the entire work, as a whole, under this
License to anyone who comes into possession of a copy. This
License will therefore apply, along with any applicable
section 7 additional terms, to the whole of the work, and all
its parts, regardless of how they are packaged. This License
gives no permission to license the work in any other way, but
it does not invalidate such permission if you have separately
received it.

d. If the work has interactive user interfaces, each must display
Appropriate Legal Notices; however, if the Program has
interactive interfaces that do not display Appropriate Legal
Notices, your work need not make them do so.

A compilation of a covered work with other separate and independent
works, which are not by their nature extensions of the covered
work, and which are not combined with it such as to form a larger
program, in or on a volume of a storage or distribution medium, is
called an "aggregate" if the compilation and its resulting
copyright are not used to limit the access or legal rights of the
compilation's users beyond what the individual works permit.
Inclusion of a covered work in an aggregate does not cause this
License to apply to the other parts of the aggregate.

6. Conveying Non-Source Forms.

You may convey a covered work in object code form under the terms
of sections 4 and 5, provided that you also convey the
machine-readable Corresponding Source under the terms of this
License, in one of these ways:

a. Convey the object code in, or embodied in, a physical product
(including a physical distribution medium), accompanied by the
Corresponding Source fixed on a durable physical medium
customarily used for software interchange.

b. Convey the object code in, or embodied in, a physical product
(including a physical distribution medium), accompanied by a
written offer, valid for at least three years and valid for as
long as you offer spare parts or customer support for that
product model, to give anyone who possesses the object code
either (1) a copy of the Corresponding Source for all the
software in the product that is covered by this License, on a
durable physical medium customarily used for software
interchange, for a price no more than your reasonable cost of
physically performing this conveying of source, or (2) access
to copy the Corresponding Source from a network server at no
charge.

c. Convey individual copies of the object code with a copy of the
written offer to provide the Corresponding Source. This
alternative is allowed only occasionally and noncommercially,
and only if you received the object code with such an offer,
in accord with subsection 6b.

d. Convey the object code by offering access from a designated
place (gratis or for a charge), and offer equivalent access to
the Corresponding Source in the same way through the same
place at no further charge. You need not require recipients
to copy the Corresponding Source along with the object code.
If the place to copy the object code is a network server, the
Corresponding Source may be on a different server (operated by
you or a third party) that supports equivalent copying
facilities, provided you maintain clear directions next to the
object code saying where to find the Corresponding Source.
Regardless of what server hosts the Corresponding Source, you
remain obligated to ensure that it is available for as long as
needed to satisfy these requirements.

e. Convey the object code using peer-to-peer transmission,
provided you inform other peers where the object code and
Corresponding Source of the work are being offered to the
general public at no charge under subsection 6d.

A separable portion of the object code, whose source code is
excluded from the Corresponding Source as a System Library, need
not be included in conveying the object code work.

A "User Product" is either (1) a "consumer product", which means
any tangible personal property which is normally used for personal,
family, or household purposes, or (2) anything designed or sold for
incorporation into a dwelling. In determining whether a product is
a consumer product, doubtful cases shall be resolved in favor of
coverage. For a particular product received by a particular user,
"normally used" refers to a typical or common use of that class of
product, regardless of the status of the particular user or of the
way in which the particular user actually uses, or expects or is
expected to use, the product. A product is a consumer product
regardless of whether the product has substantial commercial,
industrial or non-consumer uses, unless such uses represent the
only significant mode of use of the product.

"Installation Information" for a User Product means any methods,
procedures, authorization keys, or other information required to
install and execute modified versions of a covered work in that
User Product from a modified version of its Corresponding Source.
The information must suffice to ensure that the continued
functioning of the modified object code is in no case prevented or
interfered with solely because modification has been made.

If you convey an object code work under this section in, or with,
or specifically for use in, a User Product, and the conveying
occurs as part of a transaction in which the right of possession
and use of the User Product is transferred to the recipient in
perpetuity or for a fixed term (regardless of how the transaction
is characterized), the Corresponding Source conveyed under this
section must be accompanied by the Installation Information. But
this requirement does not apply if neither you nor any third party
retains the ability to install modified object code on the User
Product (for example, the work has been installed in ROM).

The requirement to provide Installation Information does not
include a requirement to continue to provide support service,
warranty, or updates for a work that has been modified or installed
by the recipient, or for the User Product in which it has been
modified or installed. Access to a network may be denied when the
modification itself materially and adversely affects the operation
of the network or violates the rules and protocols for
communication across the network.

Corresponding Source conveyed, and Installation Information
provided, in accord with this section must be in a format that is
publicly documented (and with an implementation available to the
public in source code form), and must require no special password
or key for unpacking, reading or copying.

7. Additional Terms.

"Additional permissions" are terms that supplement the terms of
this License by making exceptions from one or more of its
conditions. Additional permissions that are applicable to the
entire Program shall be treated as though they were included in
this License, to the extent that they are valid under applicable
law. If additional permissions apply only to part of the Program,
that part may be used separately under those permissions, but the
entire Program remains governed by this License without regard to
the additional permissions.

When you convey a copy of a covered work, you may at your option
remove any additional permissions from that copy, or from any part
of it. (Additional permissions may be written to require their own
removal in certain cases when you modify the work.) You may place
additional permissions on material, added by you to a covered work,
for which you have or can give appropriate copyright permission.

Notwithstanding any other provision of this License, for material
you add to a covered work, you may (if authorized by the copyright
holders of that material) supplement the terms of this License with
terms:

a. Disclaiming warranty or limiting liability differently from
the terms of sections 15 and 16 of this License; or

b. Requiring preservation of specified reasonable legal notices
or author attributions in that material or in the Appropriate
Legal Notices displayed by works containing it; or

c. Prohibiting misrepresentation of the origin of that material,
or requiring that modified versions of such material be marked
in reasonable ways as different from the original version; or

d. Limiting the use for publicity purposes of names of licensors
or authors of the material; or

e. Declining to grant rights under trademark law for use of some
trade names, trademarks, or service marks; or

f. Requiring indemnification of licensors and authors of that
material by anyone who conveys the material (or modified
versions of it) with contractual assumptions of liability to
the recipient, for any liability that these contractual
assumptions directly impose on those licensors and authors.

All other non-permissive additional terms are considered "further
restrictions" within the meaning of section 10. If the Program as
you received it, or any part of it, contains a notice stating that
it is governed by this License along with a term that is a further
restriction, you may remove that term. If a license document
contains a further restriction but permits relicensing or conveying
under this License, you may add to a covered work material governed
by the terms of that license document, provided that the further
restriction does not survive such relicensing or conveying.

If you add terms to a covered work in accord with this section, you
must place, in the relevant source files, a statement of the
additional terms that apply to those files, or a notice indicating
where to find the applicable terms.

Additional terms, permissive or non-permissive, may be stated in
the form of a separately written license, or stated as exceptions;
the above requirements apply either way.

8. Termination.

You may not propagate or modify a covered work except as expressly
provided under this License. Any attempt otherwise to propagate or
modify it is void, and will automatically terminate your rights
under this License (including any patent licenses granted under the
third paragraph of section 11).

However, if you cease all violation of this License, then your
license from a particular copyright holder is reinstated (a)
provisionally, unless and until the copyright holder explicitly and
finally terminates your license, and (b) permanently, if the
copyright holder fails to notify you of the violation by some
reasonable means prior to 60 days after the cessation.

Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from
that copyright holder, and you cure the violation prior to 30 days
after your receipt of the notice.

Termination of your rights under this section does not terminate
the licenses of parties who have received copies or rights from you
under this License. If your rights have been terminated and not
permanently reinstated, you do not qualify to receive new licenses
for the same material under section 10.

9. Acceptance Not Required for Having Copies.

You are not required to accept this License in order to receive or
run a copy of the Program. Ancillary propagation of a covered work
occurring solely as a consequence of using peer-to-peer
transmission to receive a copy likewise does not require
acceptance. However, nothing other than this License grants you
permission to propagate or modify any covered work. These actions
infringe copyright if you do not accept this License. Therefore,
by modifying or propagating a covered work, you indicate your
acceptance of this License to do so.

10. Automatic Licensing of Downstream Recipients.

Each time you convey a covered work, the recipient automatically
receives a license from the original licensors, to run, modify and
propagate that work, subject to this License. You are not
responsible for enforcing compliance by third parties with this
License.

An "entity transaction" is a transaction transferring control of an
organization, or substantially all assets of one, or subdividing an
organization, or merging organizations. If propagation of a
covered work results from an entity transaction, each party to that
transaction who receives a copy of the work also receives whatever
licenses to the work the party's predecessor in interest had or
could give under the previous paragraph, plus a right to possession
of the Corresponding Source of the work from the predecessor in
interest, if the predecessor has it or can get it with reasonable
efforts.

You may not impose any further restrictions on the exercise of the
rights granted or affirmed under this License. For example, you
may not impose a license fee, royalty, or other charge for exercise
of rights granted under this License, and you may not initiate
litigation (including a cross-claim or counterclaim in a lawsuit)
alleging that any patent claim is infringed by making, using,
selling, offering for sale, or importing the Program or any portion
of it.

11. Patents.

A "contributor" is a copyright holder who authorizes use under this
License of the Program or a work on which the Program is based.
The work thus licensed is called the contributor's "contributor
version".

A contributor's "essential patent claims" are all patent claims
owned or controlled by the contributor, whether already acquired or
hereafter acquired, that would be infringed by some manner,
permitted by this License, of making, using, or selling its
contributor version, but do not include claims that would be
infringed only as a consequence of further modification of the
contributor version. For purposes of this definition, "control"
includes the right to grant patent sublicenses in a manner
consistent with the requirements of this License.

Each contributor grants you a non-exclusive, worldwide,
royalty-free patent license under the contributor's essential
patent claims, to make, use, sell, offer for sale, import and
otherwise run, modify and propagate the contents of its contributor
version.

In the following three paragraphs, a "patent license" is any
express agreement or commitment, however denominated, not to
enforce a patent (such as an express permission to practice a
patent or covenant not to sue for patent infringement). To "grant"
such a patent license to a party means to make such an agreement or
commitment not to enforce a patent against the party.

If you convey a covered work, knowingly relying on a patent
license, and the Corresponding Source of the work is not available
for anyone to copy, free of charge and under the terms of this
License, through a publicly available network server or other
readily accessible means, then you must either (1) cause the
Corresponding Source to be so available, or (2) arrange to deprive
yourself of the benefit of the patent license for this particular
work, or (3) arrange, in a manner consistent with the requirements
of this License, to extend the patent license to downstream
recipients. "Knowingly relying" means you have actual knowledge
that, but for the patent license, your conveying the covered work
in a country, or your recipient's use of the covered work in a
country, would infringe one or more identifiable patents in that
country that you have reason to believe are valid.

If, pursuant to or in connection with a single transaction or
arrangement, you convey, or propagate by procuring conveyance of, a
covered work, and grant a patent license to some of the parties
receiving the covered work authorizing them to use, propagate,
modify or convey a specific copy of the covered work, then the
patent license you grant is automatically extended to all
recipients of the covered work and works based on it.

A patent license is "discriminatory" if it does not include within
the scope of its coverage, prohibits the exercise of, or is
conditioned on the non-exercise of one or more of the rights that
are specifically granted under this License. You may not convey a
covered work if you are a party to an arrangement with a third
party that is in the business of distributing software, under which
you make payment to the third party based on the extent of your
activity of conveying the work, and under which the third party
grants, to any of the parties who would receive the covered work
from you, a discriminatory patent license (a) in connection with
copies of the covered work conveyed by you (or copies made from
those copies), or (b) primarily for and in connection with specific
products or compilations that contain the covered work, unless you
entered into that arrangement, or that patent license was granted,
prior to 28 March 2007.

Nothing in this License shall be construed as excluding or limiting
any implied license or other defenses to infringement that may
otherwise be available to you under applicable patent law.

12. No Surrender of Others' Freedom.

If conditions are imposed on you (whether by court order, agreement
or otherwise) that contradict the conditions of this License, they
do not excuse you from the conditions of this License. If you
cannot convey a covered work so as to satisfy simultaneously your
obligations under this License and any other pertinent obligations,
then as a consequence you may not convey it at all. For example,
if you agree to terms that obligate you to collect a royalty for
further conveying from those to whom you convey the Program, the
only way you could satisfy both those terms and this License would
be to refrain entirely from conveying the Program.

13. Use with the GNU Affero General Public License.

Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work licensed
under version 3 of the GNU Affero General Public License into a
single combined work, and to convey the resulting work. The terms
of this License will continue to apply to the part which is the
covered work, but the special requirements of the GNU Affero
General Public License, section 13, concerning interaction through
a network will apply to the combination as such.

14. Revised Versions of this License.

The Free Software Foundation may publish revised and/or new
versions of the GNU General Public License from time to time. Such
new versions will be similar in spirit to the present version, but
may differ in detail to address new problems or concerns.

Each version is given a distinguishing version number. If the
Program specifies that a certain numbered version of the GNU
General Public License "or any later version" applies to it, you
have the option of following the terms and conditions either of
that numbered version or of any later version published by the Free
Software Foundation. If the Program does not specify a version
number of the GNU General Public License, you may choose any
version ever published by the Free Software Foundation.

If the Program specifies that a proxy can decide which future
versions of the GNU General Public License can be used, that
proxy's public statement of acceptance of a version permanently
authorizes you to choose that version for the Program.

Later license versions may give you additional or different
permissions. However, no additional obligations are imposed on any
author or copyright holder as a result of your choosing to follow a
later version.

15. Disclaimer of Warranty.

THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE
COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE
RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.
SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
NECESSARY SERVICING, REPAIR OR CORRECTION.

16. Limitation of Liability.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES
AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR
DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR
CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA
BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF
THE POSSIBILITY OF SUCH DAMAGES.

17. Interpretation of Sections 15 and 16.

If the disclaimer of warranty and limitation of liability provided
above cannot be given local legal effect according to their terms,
reviewing courts shall apply local law that most closely
approximates an absolute waiver of all civil liability in
connection with the Program, unless a warranty or assumption of
liability accompanies a copy of the Program in return for a fee.

END OF TERMS AND CONDITIONS
===========================

How to Apply These Terms to Your New Programs
=============================================

If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these
terms.

To do so, attach the following notices to the program. It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least the
"copyright" line and a pointer to where the full notice is found.

ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES.
Copyright (C) YEAR NAME OF AUTHOR

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper
mail.

If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:

PROGRAM Copyright (C) YEAR NAME OF AUTHOR
This program comes with ABSOLUTELY NO WARRANTY; for details type 'show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type 'show c' for details.

The hypothetical commands 'show w' and 'show c' should show the
appropriate parts of the General Public License. Of course, your
program's commands might be different; for a GUI interface, you would
use an "about box".

You should also get your employer (if you work as a programmer) or
school, if any, to sign a "copyright disclaimer" for the program, if
necessary. For more information on this, and how to apply and follow
the GNU GPL, see <http://www.gnu.org/licenses/>.

The GNU General Public License does not permit incorporating your
program into proprietary programs. If your program is a subroutine
library, you may consider it more useful to permit linking proprietary
applications with the library. If this is what you want to do, use the
GNU Lesser General Public License instead of this License. But first,
please read <http://www.gnu.org/philosophy/why-not-lgpl.html>.

File: gperf.info, Node: Contributors, Next: Motivation, Prev: Copying, Up: Top

Contributors to GNU 'gperf' Utility
***********************************

* The GNU 'gperf' perfect hash function generator utility was written
in GNU C++ by Douglas C. Schmidt. The general idea for the perfect
hash function generator was inspired by Keith Bostic's algorithm
written in C, and distributed to net.sources around 1984. The
current program is a heavily modified, enhanced, and extended
implementation of Keith's basic idea, created at the University of
California, Irvine. Bugs, patches, and suggestions should be
reported to '<bug-gperf@gnu.org>'.

* Special thanks is extended to Michael Tiemann and Doug Lea, for
providing a useful compiler, and for giving me a forum to exhibit
my creation.

In addition, Adam de Boor and Nels Olson provided many tips and
insights that greatly helped improve the quality and functionality
of 'gperf'.

* Bruno Haible enhanced and optimized the search algorithm. He also
rewrote the input routines and the output routines for better
reliability, and added a testsuite.

File: gperf.info, Node: Motivation, Next: Search Structures, Prev: Contributors, Up: Top

1 Introduction
**************

'gperf' is a perfect hash function generator written in C++. It
transforms an N element user-specified keyword set W into a perfect hash
function F. F uniquely maps keywords in W onto the range 0..K, where K
>= N-1. If K = N-1 then F is a _minimal_ perfect hash function.
'gperf' generates a 0..K element static lookup table and a pair of C
functions. These functions determine whether a given character string S
occurs in W, using at most one probe into the lookup table.

'gperf' currently generates the reserved keyword recognizer for
lexical analyzers in several production and research compilers and
language processing tools, including GNU C, GNU C++, GNU Java, GNU
Pascal, GNU Modula 3, and GNU indent. Complete C++ source code for
'gperf' is available from 'http://ftp.gnu.org/pub/gnu/gperf/'. A paper
describing 'gperf''s design and implementation in greater detail is
available in the Second USENIX C++ Conference proceedings or from
'http://www.cs.wustl.edu/~schmidt/resume.html'.

File: gperf.info, Node: Search Structures, Next: Description, Prev: Motivation, Up: Top

2 Static search structures and GNU 'gperf'
******************************************

A "static search structure" is an Abstract Data Type with certain
fundamental operations, e.g., _initialize_, _insert_, and _retrieve_.
Conceptually, all insertions occur before any retrievals. In practice,
'gperf' generates a _static_ array containing search set keywords and
any associated attributes specified by the user. Thus, there is
essentially no execution-time cost for the insertions. It is a useful
data structure for representing _static search sets_. Static search
sets occur frequently in software system applications. Typical static
search sets include compiler reserved words, assembler instruction
opcodes, and built-in shell interpreter commands. Search set members,
called "keywords", are inserted into the structure only once, usually
during program initialization, and are not generally modified at
run-time.

Numerous static search structure implementations exist, e.g., arrays,
linked lists, binary search trees, digital search tries, and hash
tables. Different approaches offer trade-offs between space utilization
and search time efficiency. For example, an N element sorted array is
space efficient, though the average-case time complexity for retrieval
operations using binary search is proportional to log N. Conversely,
hash table implementations often locate a table entry in constant time,
but typically impose additional memory overhead and exhibit poor worst
case performance.

_Minimal perfect hash functions_ provide an optimal solution for a
particular class of static search sets. A minimal perfect hash function
is defined by two properties:

* It allows keyword recognition in a static search set using at most
_one_ probe into the hash table. This represents the "perfect"
property.
* The actual memory allocated to store the keywords is precisely
large enough for the keyword set, and _no larger_. This is the
"minimal" property.

For most applications it is far easier to generate _perfect_ hash
functions than _minimal perfect_ hash functions. Moreover, non-minimal
perfect hash functions frequently execute faster than minimal ones in
practice. This phenomena occurs since searching a sparse keyword table
increases the probability of locating a "null" entry, thereby reducing
string comparisons. 'gperf''s default behavior generates _near-minimal_
perfect hash functions for keyword sets. However, 'gperf' provides many
options that permit user control over the degree of minimality and
perfection.

Static search sets often exhibit relative stability over time. For
example, Ada's 63 reserved words have remained constant for nearly a
decade. It is therefore frequently worthwhile to expend concerted
effort building an optimal search structure _once_, if it subsequently
receives heavy use multiple times. 'gperf' removes the drudgery
associated with constructing time- and space-efficient search structures
by hand. It has proven a useful and practical tool for serious
programming projects. Output from 'gperf' is currently used in several
production and research compilers, including GNU C, GNU C++, GNU Java,
GNU Pascal, and GNU Modula 3. The latter two compilers are not yet part
of the official GNU distribution. Each compiler utilizes 'gperf' to
automatically generate static search structures that efficiently
identify their respective reserved keywords.

File: gperf.info, Node: Description, Next: Options, Prev: Search Structures, Up: Top

3 High-Level Description of GNU 'gperf'
***************************************

* Menu:

The perfect hash function generator 'gperf' reads a set of "keywords"
from an input file (or from the standard input by default). It attempts
to derive a perfect hashing function that recognizes a member of the
"static keyword set" with at most a single probe into the lookup table.
If 'gperf' succeeds in generating such a function it produces a pair of
C source code routines that perform hashing and table lookup
recognition. All generated C code is directed to the standard output.
Command-line options described below allow you to modify the input and
output format to 'gperf'.

By default, 'gperf' attempts to produce time-efficient code, with
less emphasis on efficient space utilization. However, several options
exist that permit trading-off execution time for storage space and vice
versa. In particular, expanding the generated table size produces a
sparse search structure, generally yielding faster searches.
Conversely, you can direct 'gperf' to utilize a C 'switch' statement
scheme that minimizes data space storage size. Furthermore, using a C
'switch' may actually speed up the keyword retrieval time somewhat.
Actual results depend on your C compiler, of course.

In general, 'gperf' assigns values to the bytes it is using for
hashing until some set of values gives each keyword a unique value. A
helpful heuristic is that the larger the hash value range, the easier it
is for 'gperf' to find and generate a perfect hash function.
Experimentation is the key to getting the most from 'gperf'.

File: gperf.info, Node: Input Format, Next: Output Format, Prev: Description, Up: Description

3.1 Input Format to 'gperf'
===========================

You can control the input file format by varying certain command-line
arguments, in particular the '-t' option. The input's appearance is
similar to GNU utilities 'flex' and 'bison' (or UNIX utilities 'lex' and
'yacc'). Here's an outline of the general format:

declarations
%%
keywords
%%
functions

_Unlike_ 'flex' or 'bison', the declarations section and the
functions section are optional. The following sections describe the
input format for each section.

* Menu:

* Declarations:: Declarations.
* Keywords:: Format for Keyword Entries.
* Functions:: Including Additional C Functions.
* Controls for GNU indent:: Where to place directives for GNU 'indent'.

It is possible to omit the declaration section entirely, if the '-t'
option is not given. In this case the input file begins directly with
the first keyword line, e.g.:

january
february
march
april
...

File: gperf.info, Node: Declarations, Next: Keywords, Prev: Input Format, Up: Input Format

3.1.1 Declarations
------------------

The keyword input file optionally contains a section for including
arbitrary C declarations and definitions, 'gperf' declarations that act
like command-line options, as well as for providing a user-supplied
'struct'.

* Menu:

* User-supplied Struct:: Specifying keywords with attributes.
* Gperf Declarations:: Embedding command line options in the input.
* C Code Inclusion:: Including C declarations and definitions.

File: gperf.info, Node: User-supplied Struct, Next: Gperf Declarations, Prev: Declarations, Up: Declarations

3.1.1.1 User-supplied 'struct'
..............................

If the '-t' option (or, equivalently, the '%struct-type' declaration)
_is_ enabled, you _must_ provide a C 'struct' as the last component in
the declaration section from the input file. The first field in this
struct must be of type 'char *' or 'const char *' if the '-P' option is
not given, or of type 'int' if the option '-P' (or, equivalently, the
'%pic' declaration) is enabled. This first field must be called 'name',
although it is possible to modify its name with the '-K' option (or,
equivalently, the '%define slot-name' declaration) described below.

Here is a simple example, using months of the year and their
attributes as input:

struct month { char *name; int number; int days; int leap_days; };
%%
january, 1, 31, 31
february, 2, 28, 29
march, 3, 31, 31
april, 4, 30, 30
may, 5, 31, 31
june, 6, 30, 30
july, 7, 31, 31
august, 8, 31, 31
september, 9, 30, 30
october, 10, 31, 31
november, 11, 30, 30
december, 12, 31, 31

Separating the 'struct' declaration from the list of keywords and
other fields are a pair of consecutive percent signs, '%%', appearing
left justified in the first column, as in the UNIX utility 'lex'.

If the 'struct' has already been declared in an include file, it can
be mentioned in an abbreviated form, like this:

struct month;
%%
january, 1, 31, 31
...

File: gperf.info, Node: Gperf Declarations, Next: C Code Inclusion, Prev: User-supplied Struct, Up: Declarations

3.1.1.2 Gperf Declarations
..........................

The declaration section can contain 'gperf' declarations. They
influence the way 'gperf' works, like command line options do. In fact,
every such declaration is equivalent to a command line option. There
are three forms of declarations:

1. Declarations without argument, like '%compare-lengths'.

2. Declarations with an argument, like '%switch=COUNT'.

3. Declarations of names of entities in the output file, like '%define
lookup-function-name NAME'.

When a declaration is given both in the input file and as a command
line option, the command-line option's value prevails.

The following 'gperf' declarations are available.

'%delimiters=DELIMITER-LIST'
Allows you to provide a string containing delimiters used to
separate keywords from their attributes. The default is ",". This
option is essential if you want to use keywords that have embedded
commas or newlines.

'%struct-type'
Allows you to include a 'struct' type declaration for generated
code; see above for an example.

'%ignore-case'
Consider upper and lower case ASCII characters as equivalent. The
string comparison will use a case insignificant character
comparison. Note that locale dependent case mappings are ignored.

'%language=LANGUAGE-NAME'
Instructs 'gperf' to generate code in the language specified by the
option's argument. Languages handled are currently:

'KR-C'
Old-style K&R C. This language is understood by old-style C
compilers and ANSI C compilers, but ANSI C compilers may flag
warnings (or even errors) because of lacking 'const'.

'C'
Common C. This language is understood by ANSI C compilers, and
also by old-style C compilers, provided that you '#define
const' to empty for compilers which don't know about this
keyword.

'ANSI-C'
ANSI C. This language is understood by ANSI C (C89, ISO C90)
compilers, ISO C99 compilers, and C++ compilers.

'C++'
C++. This language is understood by C++ compilers.

The default is ANSI-C.

'%define slot-name NAME'
This declaration is only useful when option '-t' (or, equivalently,
the '%struct-type' declaration) has been given. By default, the
program assumes the structure component identifier for the keyword
is 'name'. This option allows an arbitrary choice of identifier
for this component, although it still must occur as the first field
in your supplied 'struct'.

'%define initializer-suffix INITIALIZERS'
This declaration is only useful when option '-t' (or, equivalently,
the '%struct-type' declaration) has been given. It permits to
specify initializers for the structure members following SLOT-NAME
in empty hash table entries. The list of initializers should start
with a comma. By default, the emitted code will zero-initialize
structure members following SLOT-NAME.

'%define hash-function-name NAME'
Allows you to specify the name for the generated hash function.
Default name is 'hash'. This option permits the use of two hash
tables in the same file.

'%define lookup-function-name NAME'
Allows you to specify the name for the generated lookup function.
Default name is 'in_word_set'. This option permits multiple
generated hash functions to be used in the same application.

'%define class-name NAME'
This option is only useful when option '-L C++' (or, equivalently,
the '%language=C++' declaration) has been given. It allows you to
specify the name of generated C++ class. Default name is
'Perfect_Hash'.

'%7bit'
This option specifies that all strings that will be passed as
arguments to the generated hash function and the generated lookup
function will solely consist of 7-bit ASCII characters (bytes in
the range 0..127). (Note that the ANSI C functions 'isalnum' and
'isgraph' do _not_ guarantee that a byte is in this range. Only an
explicit test like 'c >= 'A' && c <= 'Z'' guarantees this.)

'%compare-lengths'
Compare keyword lengths before trying a string comparison. This
option is mandatory for binary comparisons (*note Binary
Strings::). It also might cut down on the number of string
comparisons made during the lookup, since keywords with different
lengths are never compared via 'strcmp'. However, using
'%compare-lengths' might greatly increase the size of the generated
C code if the lookup table range is large (which implies that the
switch option '-S' or '%switch' is not enabled), since the length
table contains as many elements as there are entries in the lookup
table.

'%compare-strncmp'
Generates C code that uses the 'strncmp' function to perform string
comparisons. The default action is to use 'strcmp'.

'%readonly-tables'
Makes the contents of all generated lookup tables constant, i.e.,
"readonly". Many compilers can generate more efficient code for
this by putting the tables in readonly memory.

'%enum'
Define constant values using an enum local to the lookup function
rather than with #defines. This also means that different lookup
functions can reside in the same file. Thanks to James Clark
'<jjc@ai.mit.edu>'.

'%includes'
Include the necessary system include file, '<string.h>', at the
beginning of the code. By default, this is not done; the user must
include this header file himself to allow compilation of the code.

'%global-table'
Generate the static table of keywords as a static global variable,
rather than hiding it inside of the lookup function (which is the
default behavior).

'%pic'
Optimize the generated table for inclusion in shared libraries.
This reduces the startup time of programs using a shared library
containing the generated code. If the '%struct-type' declaration
(or, equivalently, the option '-t') is also given, the first field
of the user-defined struct must be of type 'int', not 'char *',
because it will contain offsets into the string pool instead of
actual strings. To convert such an offset to a string, you can use
the expression 'stringpool + O', where O is the offset. The string
pool name can be changed through the '%define string-pool-name'
declaration.

'%define string-pool-name NAME'
Allows you to specify the name of the generated string pool created
by the declaration '%pic' (or, equivalently, the option '-P'). The
default name is 'stringpool'. This declaration permits the use of
two hash tables in the same file, with '%pic' and even when the
'%global-table' declaration (or, equivalently, the option '-G') is
given.

'%null-strings'
Use NULL strings instead of empty strings for empty keyword table
entries. This reduces the startup time of programs using a shared
library containing the generated code (but not as much as the
declaration '%pic'), at the expense of one more test-and-branch
instruction at run time.

'%define constants-prefix PREFIX'
Allows you to specify a prefix for the constants 'TOTAL_KEYWORDS',
'MIN_WORD_LENGTH', 'MAX_WORD_LENGTH', and so on. This option
permits the use of two hash tables in the same file, even when the
option '-E' (or, equivalently, the '%enum' declaration) is not
given or the option '-G' (or, equivalently, the '%global-table'
declaration) is given.

'%define word-array-name NAME'
Allows you to specify the name for the generated array containing
the hash table. Default name is 'wordlist'. This option permits
the use of two hash tables in the same file, even when the option
'-G' (or, equivalently, the '%global-table' declaration) is given.

'%define length-table-name NAME'
Allows you to specify the name for the generated array containing
the length table. Default name is 'lengthtable'. This option
permits the use of two length tables in the same file, even when
the option '-G' (or, equivalently, the '%global-table' declaration)
is given.

'%switch=COUNT'
Causes the generated C code to use a 'switch' statement scheme,
rather than an array lookup table. This can lead to a reduction in
both time and space requirements for some input files. The
argument to this option determines how many 'switch' statements are
generated. A value of 1 generates 1 'switch' containing all the
elements, a value of 2 generates 2 tables with 1/2 the elements in
each 'switch', etc. This is useful since many C compilers cannot
correctly generate code for large 'switch' statements. This option
was inspired in part by Keith Bostic's original C program.

'%omit-struct-type'
Prevents the transfer of the type declaration to the output file.
Use this option if the type is already defined elsewhere.

File: gperf.info, Node: C Code Inclusion, Prev: Gperf Declarations, Up: Declarations

3.1.1.3 C Code Inclusion
........................

Using a syntax similar to GNU utilities 'flex' and 'bison', it is
possible to directly include C source text and comments verbatim into
the generated output file. This is accomplished by enclosing the region
inside left-justified surrounding '%{', '%}' pairs. Here is an input
fragment based on the previous example that illustrates this feature:

%{
#include <assert.h>
/* This section of code is inserted directly into the output. */
int return_month_days (struct month *months, int is_leap_year);
%}
struct month { char *name; int number; int days; int leap_days; };
%%
january, 1, 31, 31
february, 2, 28, 29
march, 3, 31, 31
...

File: gperf.info, Node: Keywords, Next: Functions, Prev: Declarations, Up: Input Format

3.1.2 Format for Keyword Entries
--------------------------------

The second input file format section contains lines of keywords and
any associated attributes you might supply. A line beginning with '#'
in the first column is considered a comment. Everything following the
'#' is ignored, up to and including the following newline. A line
beginning with '%' in the first column is an option declaration and must
not occur within the keywords section.

The first field of each non-comment line is always the keyword
itself. It can be given in two ways: as a simple name, i.e., without
surrounding string quotation marks, or as a string enclosed in
double-quotes, in C syntax, possibly with backslash escapes like '\"' or
'\234' or '\xa8'. In either case, it must start right at the beginning
of the line, without leading whitespace. In this context, a "field" is
considered to extend up to, but not include, the first blank, comma, or
newline. Here is a simple example taken from a partial list of C
reserved words:

# These are a few C reserved words, see the c.gperf file
# for a complete list of ANSI C reserved words.
unsigned
sizeof
switch
signed
if
default
for
while
return

Note that unlike 'flex' or 'bison' the first '%%' marker may be
elided if the declaration section is empty.

Additional fields may optionally follow the leading keyword. Fields
should be separated by commas, and terminate at the end of line. What
these fields mean is entirely up to you; they are used to initialize the
elements of the user-defined 'struct' provided by you in the declaration
section. If the '-t' option (or, equivalently, the '%struct-type'
declaration) is _not_ enabled these fields are simply ignored. All
previous examples except the last one contain keyword attributes.

File: gperf.info, Node: Functions, Next: Controls for GNU indent, Prev: Keywords, Up: Input Format

3.1.3 Including Additional C Functions
--------------------------------------

The optional third section also corresponds closely with conventions
found in 'flex' and 'bison'. All text in this section, starting at the
final '%%' and extending to the end of the input file, is included
verbatim into the generated output file. Naturally, it is your
responsibility to ensure that the code contained in this section is
valid C.

File: gperf.info, Node: Controls for GNU indent, Prev: Functions, Up: Input Format

3.1.4 Where to place directives for GNU 'indent'.
-------------------------------------------------

If you want to invoke GNU 'indent' on a 'gperf' input file, you will
see that GNU 'indent' doesn't understand the '%%', '%{' and '%}'
directives that control 'gperf''s interpretation of the input file.
Therefore you have to insert some directives for GNU 'indent'. More
precisely, assuming the most general input file structure

declarations part 1
%{
verbatim code
%}
declarations part 2
%%
keywords
%%
functions

you would insert '*INDENT-OFF*' and '*INDENT-ON*' comments as follows:

/* *INDENT-OFF* */
declarations part 1
%{
/* *INDENT-ON* */
verbatim code
/* *INDENT-OFF* */
%}
declarations part 2
%%
keywords
%%
/* *INDENT-ON* */
functions

File: gperf.info, Node: Output Format, Next: Binary Strings, Prev: Input Format, Up: Description

3.2 Output Format for Generated C Code with 'gperf'
===================================================

Several options control how the generated C code appears on the
standard output. Two C functions are generated. They are called 'hash'
and 'in_word_set', although you may modify their names with a
command-line option. Both functions require two arguments, a string,
'char *' STR, and a length parameter, 'int' LEN. Their default function
prototypes are as follows:

-- Function: unsigned int hash (const char * STR, size_t LEN)
By default, the generated 'hash' function returns an integer value
created by adding LEN to several user-specified STR byte positions
indexed into an "associated values" table stored in a local static
array. The associated values table is constructed internally by
'gperf' and later output as a static local C array called
'hash_table'. The relevant selected positions (i.e. indices into
STR) are specified via the '-k' option when running 'gperf', as
detailed in the _Options_ section below (*note Options::).

-- Function: in_word_set (const char * STR, size_t LEN)
If STR is in the keyword set, returns a pointer to that keyword.
More exactly, if the option '-t' (or, equivalently, the
'%struct-type' declaration) was given, it returns a pointer to the
matching keyword's structure. Otherwise it returns 'NULL'.

If the option '-c' (or, equivalently, the '%compare-strncmp'
declaration) is not used, STR must be a NUL terminated string of exactly
length LEN. If '-c' (or, equivalently, the '%compare-strncmp'
declaration) is used, STR must simply be an array of LEN bytes and does
not need to be NUL terminated.

The code generated for these two functions is affected by the
following options:

'-t'
'--struct-type'
Make use of the user-defined 'struct'.

'-S TOTAL-SWITCH-STATEMENTS'
'--switch=TOTAL-SWITCH-STATEMENTS'
Generate 1 or more C 'switch' statement rather than use a large,
(and potentially sparse) static array. Although the exact time and
space savings of this approach vary according to your C compiler's
degree of optimization, this method often results in smaller and
faster code.

If the '-t' and '-S' options (or, equivalently, the '%struct-type'
and '%switch' declarations) are omitted, the default action is to
generate a 'char *' array containing the keywords, together with
additional empty strings used for padding the array. By experimenting
with the various input and output options, and timing the resulting C
code, you can determine the best option choices for different keyword
set characteristics.

File: gperf.info, Node: Binary Strings, Next: Controlling Identifiers, Prev: Output Format, Up: Description

3.3 Use of NUL bytes
====================

By default, the code generated by 'gperf' operates on zero terminated
strings, the usual representation of strings in C. This means that the
keywords in the input file must not contain NUL bytes, and the STR
argument passed to 'hash' or 'in_word_set' must be NUL terminated and
have exactly length LEN.

If option '-c' (or, equivalently, the '%compare-strncmp' declaration)
is used, then the STR argument does not need to be NUL terminated. The
code generated by 'gperf' will only access the first LEN, not LEN+1,
bytes starting at STR. However, the keywords in the input file still
must not contain NUL bytes.

If option '-l' (or, equivalently, the '%compare-lengths' declaration)
is used, then the hash table performs binary comparison. The keywords
in the input file may contain NUL bytes, written in string syntax as
'\000' or '\x00', and the code generated by 'gperf' will treat NUL like
any other byte. Also, in this case the '-c' option (or, equivalently,
the '%compare-strncmp' declaration) is ignored.

File: gperf.info, Node: Controlling Identifiers, Next: Output Copyright, Prev: Binary Strings, Up: Description

3.4 Controlling Identifiers
===========================

The identifiers of the functions, tables, and constants defined by
the code generated by 'gperf' can be controlled through 'gperf'
declarations or the equivalent command-line options. This is useful for
three purposes:

* Esthetics of the generated code.

For this purpose, just use the available declarations or options at
will.

* Controlling the exported identifiers of a library.

Assume you include code generated by 'gperf' in a library, and to
avoid collisions with other libraries, you want to ensure that all
exported identifiers of this library start with a certain prefix.

By default, the only exported identifier is the lookup function.
You can therefore use the option '-N' (or, equivalently, the
'%define lookup-function-name' declaration).

When you use the option '-L C++' (or, equivalently, the
'%language=C++' declaration), the only exported entity is a class.
You control its name through the option '-Z' (or, equivalently, the
'%define class-name' declaration).

* Allowing multiple 'gperf' generated codes in a single compilation
unit.

Assume you invoke 'gperf' multiple times, with different input
files, and want the generated code to included from the same source
file. In this case, you have to customize not only the exported
identifiers, but also the names of functions with 'static' scope,
types, and constants.

By default, you will have to deal with the lookup function, the
hash function, and the constants. You should therefore use the
option '-N' (or, equivalently, the '%define lookup-function-name'
declaration), the option '-H' (or, equivalently, the '%define
hash-function-name' declaration), and the option
'--constants-prefix' (or, equivalently, the '%define
constants-prefix' declaration).

If you use the option '-G' (or, equivalently, the '%global-table'
declaration), you will also have to deal with the word array, the
length table if present, and the string pool if present. This
means: You should use the option '-W' (or, equivalently, the
'%define word-array-name' declaration). If you use the option '-l'
(or, equivalently, the '%compare-lengths' declaration), you should
use the option '--length-table-name' (or, equivalently, the
'%define length-table-name' declaration). If you use the option
'-P' (or, equivalently, the '%pic' declaration), you should use the
option '-Q' (or, equivalently, the '%define string-pool-name'
declaration).

File: gperf.info, Node: Output Copyright, Prev: Controlling Identifiers, Up: Description

3.5 The Copyright of the Output
===============================

'gperf' is under GPL, but that does not cause the output produced by
'gperf' to be under GPL. The reason is that the output contains only
small pieces of text that come directly from 'gperf''s source code -
only about 7 lines long, too small for being significant -, and
therefore the output is not a "work based on 'gperf'" (in the sense of
the GPL version 3).

On the other hand, the output produced by 'gperf' contains
essentially all of the input file. Therefore the output is a
"derivative work" of the input (in the sense of U.S. copyright law); and
its copyright status depends on the copyright of the input. For most
software licenses, the result is that the the output is under the same
license, with the same copyright holder, as the input that was passed to
'gperf'.

File: gperf.info, Node: Options, Next: Bugs, Prev: Description, Up: Top

4 Invoking 'gperf'
******************

There are _many_ options to 'gperf'. They were added to make the
program more convenient for use with real applications. "On-line" help
is readily available via the '--help' option. Here is the complete list
of options.

* Menu:

* Output File:: Specifying the Location of the Output File
* Input Details:: Options that affect Interpretation of the Input File
* Output Language:: Specifying the Language for the Output Code
* Output Details:: Fine tuning Details in the Output Code
* Algorithmic Details:: Changing the Algorithms employed by 'gperf'
* Verbosity:: Informative Output

File: gperf.info, Node: Output File, Next: Input Details, Prev: Options, Up: Options

4.1 Specifying the Location of the Output File
==============================================

'--output-file=FILE'
Allows you to specify the name of the file to which the output is
written to.

The results are written to standard output if no output file is
specified or if it is '-'.

File: gperf.info, Node: Input Details, Next: Output Language, Prev: Output File, Up: Options

4.2 Options that affect Interpretation of the Input File
========================================================

These options are also available as declarations in the input file
(*note Gperf Declarations::).

'-e KEYWORD-DELIMITER-LIST'
'--delimiters=KEYWORD-DELIMITER-LIST'
Allows you to provide a string containing delimiters used to
separate keywords from their attributes. The default is ",". This
option is essential if you want to use keywords that have embedded
commas or newlines. One useful trick is to use -e'TAB', where TAB
is the literal tab character.

'-t'
'--struct-type'
Allows you to include a 'struct' type declaration for generated
code. Any text before a pair of consecutive '%%' is considered
part of the type declaration. Keywords and additional fields may
follow this, one group of fields per line. A set of examples for
generating perfect hash tables and functions for Ada, C, C++,
Pascal, Modula 2, Modula 3 and JavaScript reserved words are
distributed with this release.

'--ignore-case'
Consider upper and lower case ASCII characters as equivalent. The
string comparison will use a case insignificant character
comparison. Note that locale dependent case mappings are ignored.
This option is therefore not suitable if a properly
internationalized or locale aware case mapping should be used.
(For example, in a Turkish locale, the upper case equivalent of the
lowercase ASCII letter 'i' is the non-ASCII character 'capital i
with dot above'.) For this case, it is better to apply an
uppercase or lowercase conversion on the string before passing it
to the 'gperf' generated function.

File: gperf.info, Node: Output Language, Next: Output Details, Prev: Input Details, Up: Options

4.3 Options to specify the Language for the Output Code
=======================================================

These options are also available as declarations in the input file
(*note Gperf Declarations::).

'-L GENERATED-LANGUAGE-NAME'
'--language=GENERATED-LANGUAGE-NAME'
Instructs 'gperf' to generate code in the language specified by the
option's argument. Languages handled are currently:

'KR-C'
Old-style K&R C. This language is understood by old-style C
compilers and ANSI C compilers, but ANSI C compilers may flag
warnings (or even errors) because of lacking 'const'.

'C'
Common C. This language is understood by ANSI C compilers, and
also by old-style C compilers, provided that you '#define
const' to empty for compilers which don't know about this
keyword.

'ANSI-C'
ANSI C. This language is understood by ANSI C compilers and
C++ compilers.

'C++'
C++. This language is understood by C++ compilers.

The default is ANSI-C.

'-a'
This option is supported for compatibility with previous releases
of 'gperf'. It does not do anything.

'-g'
This option is supported for compatibility with previous releases
of 'gperf'. It does not do anything.

File: gperf.info, Node: Output Details, Next: Algorithmic Details, Prev: Output Language, Up: Options

4.4 Options for fine tuning Details in the Output Code
======================================================

Most of these options are also available as declarations in the input
file (*note Gperf Declarations::).

'-K SLOT-NAME'
'--slot-name=SLOT-NAME'
This option is only useful when option '-t' (or, equivalently, the
'%struct-type' declaration) has been given. By default, the
program assumes the structure component identifier for the keyword
is 'name'. This option allows an arbitrary choice of identifier
for this component, although it still must occur as the first field
in your supplied 'struct'.

'-F INITIALIZERS'
'--initializer-suffix=INITIALIZERS'
This option is only useful when option '-t' (or, equivalently, the
'%struct-type' declaration) has been given. It permits to specify
initializers for the structure members following SLOT-NAME in empty
hash table entries. The list of initializers should start with a
comma. By default, the emitted code will zero-initialize structure
members following SLOT-NAME.

'-H HASH-FUNCTION-NAME'
'--hash-function-name=HASH-FUNCTION-NAME'
Allows you to specify the name for the generated hash function.
Default name is 'hash'. This option permits the use of two hash
tables in the same file.

'-N LOOKUP-FUNCTION-NAME'
'--lookup-function-name=LOOKUP-FUNCTION-NAME'
Allows you to specify the name for the generated lookup function.
Default name is 'in_word_set'. This option permits multiple
generated hash functions to be used in the same application.

'-Z CLASS-NAME'
'--class-name=CLASS-NAME'
This option is only useful when option '-L C++' (or, equivalently,
the '%language=C++' declaration) has been given. It allows you to
specify the name of generated C++ class. Default name is
'Perfect_Hash'.

'-7'
'--seven-bit'
This option specifies that all strings that will be passed as
arguments to the generated hash function and the generated lookup
function will solely consist of 7-bit ASCII characters (bytes in
the range 0..127). (Note that the ANSI C functions 'isalnum' and
'isgraph' do _not_ guarantee that a byte is in this range. Only an
explicit test like 'c >= 'A' && c <= 'Z'' guarantees this.) This
was the default in versions of 'gperf' earlier than 2.7; now the
default is to support 8-bit and multibyte characters.

'-l'
'--compare-lengths'
Compare keyword lengths before trying a string comparison. This
option is mandatory for binary comparisons (*note Binary
Strings::). It also might cut down on the number of string
comparisons made during the lookup, since keywords with different
lengths are never compared via 'strcmp'. However, using '-l' might
greatly increase the size of the generated C code if the lookup
table range is large (which implies that the switch option '-S' or
'%switch' is not enabled), since the length table contains as many
elements as there are entries in the lookup table.

'-c'
'--compare-strncmp'
Generates C code that uses the 'strncmp' function to perform string
comparisons. The default action is to use 'strcmp'.

'-C'
'--readonly-tables'
Makes the contents of all generated lookup tables constant, i.e.,
"readonly". Many compilers can generate more efficient code for
this by putting the tables in readonly memory.

'-E'
'--enum'
Define constant values using an enum local to the lookup function
rather than with #defines. This also means that different lookup
functions can reside in the same file. Thanks to James Clark
'<jjc@ai.mit.edu>'.

'-I'
'--includes'
Include the necessary system include file, '<string.h>', at the
beginning of the code. By default, this is not done; the user must
include this header file himself to allow compilation of the code.

'-G'
'--global-table'
Generate the static table of keywords as a static global variable,
rather than hiding it inside of the lookup function (which is the
default behavior).

'-P'
'--pic'
Optimize the generated table for inclusion in shared libraries.
This reduces the startup time of programs using a shared library
containing the generated code. If the option '-t' (or,
equivalently, the '%struct-type' declaration) is also given, the
first field of the user-defined struct must be of type 'int', not
'char *', because it will contain offsets into the string pool
instead of actual strings. To convert such an offset to a string,
you can use the expression 'stringpool + O', where O is the offset.
The string pool name can be changed through the option
'--string-pool-name'.

'-Q STRING-POOL-NAME'
'--string-pool-name=STRING-POOL-NAME'
Allows you to specify the name of the generated string pool created
by option '-P'. The default name is 'stringpool'. This option
permits the use of two hash tables in the same file, with '-P' and
even when the option '-G' (or, equivalently, the '%global-table'
declaration) is given.

'--null-strings'
Use NULL strings instead of empty strings for empty keyword table
entries. This reduces the startup time of programs using a shared
library containing the generated code (but not as much as option
'-P'), at the expense of one more test-and-branch instruction at
run time.

'--constants-prefix=PREFIX'
Allows you to specify a prefix for the constants 'TOTAL_KEYWORDS',
'MIN_WORD_LENGTH', 'MAX_WORD_LENGTH', and so on. This option
permits the use of two hash tables in the same file, even when the
option '-E' (or, equivalently, the '%enum' declaration) is not
given or the option '-G' (or, equivalently, the '%global-table'
declaration) is given.

'-W HASH-TABLE-ARRAY-NAME'
'--word-array-name=HASH-TABLE-ARRAY-NAME'
Allows you to specify the name for the generated array containing
the hash table. Default name is 'wordlist'. This option permits
the use of two hash tables in the same file, even when the option
'-G' (or, equivalently, the '%global-table' declaration) is given.

'--length-table-name=LENGTH-TABLE-ARRAY-NAME'
Allows you to specify the name for the generated array containing
the length table. Default name is 'lengthtable'. This option
permits the use of two length tables in the same file, even when
the option '-G' (or, equivalently, the '%global-table' declaration)
is given.

'-S TOTAL-SWITCH-STATEMENTS'
'--switch=TOTAL-SWITCH-STATEMENTS'
Causes the generated C code to use a 'switch' statement scheme,
rather than an array lookup table. This can lead to a reduction in
both time and space requirements for some input files. The
argument to this option determines how many 'switch' statements are
generated. A value of 1 generates 1 'switch' containing all the
elements, a value of 2 generates 2 tables with 1/2 the elements in
each 'switch', etc. This is useful since many C compilers cannot
correctly generate code for large 'switch' statements. This option
was inspired in part by Keith Bostic's original C program.

'-T'
'--omit-struct-type'
Prevents the transfer of the type declaration to the output file.
Use this option if the type is already defined elsewhere.

'-p'
This option is supported for compatibility with previous releases
of 'gperf'. It does not do anything.

File: gperf.info, Node: Algorithmic Details, Next: Verbosity, Prev: Output Details, Up: Options

4.5 Options for changing the Algorithms employed by 'gperf'
===========================================================

'-k SELECTED-BYTE-POSITIONS'
'--key-positions=SELECTED-BYTE-POSITIONS'
Allows selection of the byte positions used in the keywords' hash
function. The allowable choices range between 1-255, inclusive.
The positions are separated by commas, e.g., '-k 9,4,13,14'; ranges
may be used, e.g., '-k 2-7'; and positions may occur in any order.
Furthermore, the wildcard '*' causes the generated hash function to
consider *all* byte positions in each keyword, whereas '$'
instructs the hash function to use the "final byte" of a keyword
(this is the only way to use a byte position greater than 255,
incidentally).

For instance, the option '-k 1,2,4,6-10,'$'' generates a hash
function that considers positions 1,2,4,6,7,8,9,10, plus the last
byte in each keyword (which may be at a different position for each
keyword, obviously). Keywords with length less than the indicated
byte positions work properly, since selected byte positions
exceeding the keyword length are simply not referenced in the hash
function.

This option is not normally needed since version 2.8 of 'gperf';
the default byte positions are computed depending on the keyword
set, through a search that minimizes the number of byte positions.

'-D'
'--duplicates'
Handle keywords whose selected byte sets hash to duplicate values.
Duplicate hash values can occur if a set of keywords has the same
names, but possesses different attributes, or if the selected byte
positions are not well chosen. With the -D option 'gperf' treats
all these keywords as part of an equivalence class and generates a
perfect hash function with multiple comparisons for duplicate
keywords. It is up to you to completely disambiguate the keywords
by modifying the generated C code. However, 'gperf' helps you out
by organizing the output.

Using this option usually means that the generated hash function is
no longer perfect. On the other hand, it permits 'gperf' to work
on keyword sets that it otherwise could not handle.

'-m ITERATIONS'
'--multiple-iterations=ITERATIONS'
Perform multiple choices of the '-i' and '-j' values, and choose
the best results. This increases the running time by a factor of
ITERATIONS but does a good job minimizing the generated table size.

'-i INITIAL-VALUE'
'--initial-asso=INITIAL-VALUE'
Provides an initial VALUE for the associate values array. Default
is 0. Increasing the initial value helps inflate the final table
size, possibly leading to more time efficient keyword lookups.
Note that this option is not particularly useful when '-S' (or,
equivalently, '%switch') is used. Also, '-i' is overridden when
the '-r' option is used.

'-j JUMP-VALUE'
'--jump=JUMP-VALUE'
Affects the "jump value", i.e., how far to advance the associated
byte value upon collisions. JUMP-VALUE is rounded up to an odd
number, the default is 5. If the JUMP-VALUE is 0 'gperf' jumps by
random amounts.

'-n'
'--no-strlen'
Instructs the generator not to include the length of a keyword when
computing its hash value. This may save a few assembly
instructions in the generated lookup table.

'-r'
'--random'
Utilizes randomness to initialize the associated values table.
This frequently generates solutions faster than using deterministic
initialization (which starts all associated values at 0).
Furthermore, using the randomization option generally increases the
size of the table.

'-s SIZE-MULTIPLE'
'--size-multiple=SIZE-MULTIPLE'
Affects the size of the generated hash table. The numeric argument
for this option indicates "how many times larger or smaller" the
maximum associated value range should be, in relationship to the
number of keywords. It can be written as an integer, a
floating-point number or a fraction. For example, a value of 3
means "allow the maximum associated value to be about 3 times
larger than the number of input keywords". Conversely, a value of
1/3 means "allow the maximum associated value to be about 3 times
smaller than the number of input keywords". Values smaller than 1
are useful for limiting the overall size of the generated hash
table, though the option '-m' is better at this purpose.

If 'generate switch' option '-S' (or, equivalently, '%switch') is
_not_ enabled, the maximum associated value influences the static
array table size, and a larger table should decrease the time
required for an unsuccessful search, at the expense of extra table
space.

The default value is 1, thus the default maximum associated value
about the same size as the number of keywords (for efficiency, the
maximum associated value is always rounded up to a power of 2).
The actual table size may vary somewhat, since this technique is
essentially a heuristic.

File: gperf.info, Node: Verbosity, Prev: Algorithmic Details, Up: Options

4.6 Informative Output
======================

'-h'
'--help'
Prints a short summary on the meaning of each program option.
Aborts further program execution.

'-v'
'--version'
Prints out the current version number.

'-d'
'--debug'
Enables the debugging option. This produces verbose diagnostics to
"standard error" when 'gperf' is executing. It is useful both for
maintaining the program and for determining whether a given set of
options is actually speeding up the search for a solution. Some
useful information is dumped at the end of the program when the
'-d' option is enabled.

File: gperf.info, Node: Bugs, Next: Projects, Prev: Options, Up: Top

5 Known Bugs and Limitations with 'gperf'
*****************************************

The following are some limitations with the current release of
'gperf':

* The 'gperf' utility is tuned to execute quickly, and works quickly
for small to medium size data sets (around 1000 keywords). It is
extremely useful for maintaining perfect hash functions for
compiler keyword sets. Several recent enhancements now enable
'gperf' to work efficiently on much larger keyword sets (over
15,000 keywords). When processing large keyword sets it helps
greatly to have over 8 megs of RAM.

* The size of the generate static keyword array can get _extremely_
large if the input keyword file is large or if the keywords are
quite similar. This tends to slow down the compilation of the
generated C code, and _greatly_ inflates the object code size. If
this situation occurs, consider using the '-S' option to reduce
data size, potentially increasing keyword recognition time a
negligible amount. Since many C compilers cannot correctly
generate code for large switch statements it is important to
qualify the -S option with an appropriate numerical argument that
controls the number of switch statements generated.

* The maximum number of selected byte positions has an arbitrary
limit of 255. This restriction should be removed, and if anyone
considers this a problem write me and let me know so I can remove
the constraint.

File: gperf.info, Node: Projects, Next: Bibliography, Prev: Bugs, Up: Top

6 Things Still Left to Do
*************************

It should be "relatively" easy to replace the current perfect hash
function algorithm with a more exhaustive approach; the perfect hash
module is essential independent from other program modules. Additional
worthwhile improvements include:

* Another useful extension involves modifying the program to generate
"minimal" perfect hash functions (under certain circumstances, the
current version can be rather extravagant in the generated table
size). This is mostly of theoretical interest, since a sparse
table often produces faster lookups, and use of the '-S' 'switch'
option can minimize the data size, at the expense of slightly
longer lookups (note that the gcc compiler generally produces good
code for 'switch' statements, reducing the need for more complex
schemes).

* In addition to improving the algorithm, it would also be useful to
generate an Ada package as the code output, in addition to the
current C and C++ routines.

File: gperf.info, Node: Bibliography, Next: Concept Index, Prev: Projects, Up: Top

7 Bibliography
**************

[1] Chang, C.C.: A Scheme for Constructing Ordered Minimal Perfect
Hashing Functions Information Sciences 39(1986), 187-195.

[2] Cichelli, Richard J. Author's Response to "On Cichelli's Minimal
Perfect Hash Functions Method" Communications of the ACM, 23,
12(December 1980), 729.

[3] Cichelli, Richard J. Minimal Perfect Hash Functions Made Simple
Communications of the ACM, 23, 1(January 1980), 17-19.

[4] Cook, C. R. and Oldehoeft, R.R. A Letter Oriented Minimal Perfect
Hashing Function SIGPLAN Notices, 17, 9(September 1982), 18-27.

[5] Cormack, G. V. and Horspool, R. N. S. and Kaiserwerth, M. Practical
Perfect Hashing Computer Journal, 28, 1(January 1985), 54-58.

[6] Jaeschke, G. Reciprocal Hashing: A Method for Generating Minimal
Perfect Hashing Functions Communications of the ACM, 24, 12(December
1981), 829-833.

[7] Jaeschke, G. and Osterburg, G. On Cichelli's Minimal Perfect Hash
Functions Method Communications of the ACM, 23, 12(December 1980),
728-729.

[8] Sager, Thomas J. A Polynomial Time Generator for Minimal Perfect
Hash Functions Communications of the ACM, 28, 5(December 1985), 523-532

[9] Schmidt, Douglas C. GPERF: A Perfect Hash Function Generator Second
USENIX C++ Conference Proceedings, April 1990.

[10] Schmidt, Douglas C. GPERF: A Perfect Hash Function Generator C++
Report, SIGS 10 10 (November/December 1998).

[11] Sebesta, R.W. and Taylor, M.A. Minimal Perfect Hash Functions for
Reserved Word Lists SIGPLAN Notices, 20, 12(September 1985), 47-53.

[12] Sprugnoli, R. Perfect Hashing Functions: A Single Probe Retrieving
Method for Static Sets Communications of the ACM, 20 11(November 1977),
841-850.

[13] Stallman, Richard M. Using and Porting GNU CC Free Software
Foundation, 1988.

[14] Stroustrup, Bjarne The C++ Programming Language. Addison-Wesley,
1986.

[15] Tiemann, Michael D. User's Guide to GNU C++ Free Software
Foundation, 1989.

File: gperf.info, Node: Concept Index, Prev: Bibliography, Up: Top

Concept Index
*************

[index]
* Menu:

* '%%': User-supplied Struct.
(line 33)
* '%7bit': Gperf Declarations. (line 95)
* '%compare-lengths': Gperf Declarations. (line 103)
* '%compare-strncmp': Gperf Declarations. (line 115)
* '%define class-name': Gperf Declarations. (line 89)
* '%define constants-prefix': Gperf Declarations. (line 167)
* '%define hash-function-name': Gperf Declarations. (line 79)
* '%define initializer-suffix': Gperf Declarations. (line 71)
* '%define length-table-name': Gperf Declarations. (line 181)
* '%define lookup-function-name': Gperf Declarations. (line 84)
* '%define slot-name': Gperf Declarations. (line 63)
* '%define string-pool-name': Gperf Declarations. (line 152)
* '%define word-array-name': Gperf Declarations. (line 175)
* '%delimiters': Gperf Declarations. (line 24)
* '%enum': Gperf Declarations. (line 124)
* '%global-table': Gperf Declarations. (line 135)
* '%ignore-case': Gperf Declarations. (line 34)
* '%includes': Gperf Declarations. (line 130)
* '%language': Gperf Declarations. (line 39)
* '%null-strings': Gperf Declarations. (line 160)
* '%omit-struct-type': Gperf Declarations. (line 199)
* '%pic': Gperf Declarations. (line 140)
* '%readonly-tables': Gperf Declarations. (line 119)
* '%struct-type': Gperf Declarations. (line 30)
* '%switch': Gperf Declarations. (line 188)
* '%{': C Code Inclusion. (line 6)
* '%}': C Code Inclusion. (line 6)
* Array name: Output Details. (line 137)
* Array name <1>: Output Details. (line 143)
* Bugs: Contributors. (line 6)
* Class name: Output Details. (line 41)
* Constants definition: Output Details. (line 82)
* Constants prefix: Output Details. (line 128)
* Copyright: Output Copyright. (line 6)
* Declaration section: Input Format. (line 6)
* Delimiters: Input Details. (line 11)
* Duplicates: Algorithmic Details. (line 32)
* Format: Input Format. (line 6)
* Functions section: Input Format. (line 6)
* hash: Output Format. (line 13)
* hash table: Output Format. (line 6)
* Initializers: Output Details. (line 20)
* in_word_set: Output Format. (line 23)
* Jump value: Algorithmic Details. (line 63)
* Keywords section: Input Format. (line 6)
* Minimal perfect hash functions: Search Structures. (line 30)
* NUL: Binary Strings. (line 6)
* Slot name: Output Details. (line 11)
* Static search structure: Search Structures. (line 6)
* 'switch': Output Format. (line 44)
* 'switch' <1>: Output Details. (line 151)

Tag Table:
Node: Top1234
Node: Copying3454
Node: Contributors40977
Node: Motivation42166
Node: Search Structures43298
Node: Description46856
Node: Input Format48880
Node: Declarations50025
Node: User-supplied Struct50613
Node: Gperf Declarations52228
Node: C Code Inclusion61433
Node: Keywords62276
Node: Functions64224
Node: Controls for GNU indent64762
Node: Output Format65713
Node: Binary Strings68496
Node: Controlling Identifiers69679
Node: Output Copyright72443
Node: Options73390
Node: Output File74179
Node: Input Details74571
Node: Output Language76410
Node: Output Details77835
Node: Algorithmic Details85502
Node: Verbosity90753
Node: Bugs91464
Node: Projects93060
Node: Bibliography94192
Node: Concept Index96207

End Tag Table