Overall license

The license for ccache as a whole is as follows:

  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, write to the Free Software Foundation, Inc., 51 Franklin
  Street, Fifth Floor, Boston, MA 02110-1301 USA

The full license text can be found in GPL-3.0.txt and at http://www.gnu.org/licenses/gpl-3.0.html.

ccache is a collective work with contributions from many people, listed in AUTHORS.adoc and at https://ccache.dev/credits.html. Subsequent additions by contributing authors are implicitly licensed to the public under the same terms (GNU GPL version 3 or later), but the contributing authors retain copyrights on their portions of the work.

The copyright for ccache as a whole is as follows:

  Copyright (C) 2002-2007 Andrew Tridgell
  Copyright (C) 2009-2019 Joel Rosdahl

Files derived from other sources

The ccache distribution contain some files from other sources and some have been modified for use in ccache. These files all carry attribution notices, and may qualify as “separate and independent works in themselves” for purposes of the GPL: that is, if separated from the ccache sources, they may be usable under less restrictive terms.

src/getopt_long.[hc]

This implementation of getopt_long() was copied from PostgreSQL and has the following license text:

  Portions Copyright (c) 1987, 1993, 1994
  The Regents of the University of California.  All rights reserved.

  Portions Copyright (c) 2003
  PostgreSQL Global Development Group

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:
  1. Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.
  3. Neither the name of the University nor the names of its contributors
     may be used to endorse or promote products derived from this software
     without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  SUCH DAMAGE.

src/hashtable*.[hc]

This code comes from http://www.cl.cam.ac.uk/~cwc22/hashtable/ with the following license:

  Copyright (c) 2002, 2004, Christopher Clark
  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
      and/or other materials provided with the distribution.

    * Neither the name of the original author; nor the names of any
      contributors may be used to endorse or promote products derived from this
      software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  POSSIBILITY OF SUCH DAMAGE.

m4/feature_macros.m4

This Autoconf M4 snippet comes from Python 2.6’s configure.in with the following license:

  A. HISTORY OF THE SOFTWARE
  ==========================

  Python was created in the early 1990s by Guido van Rossum at Stichting
  Mathematisch Centrum (CWI, see http://www.cwi.nl) in the Netherlands
  as a successor of a language called ABC.  Guido remains Python's
  principal author, although it includes many contributions from others.

  In 1995, Guido continued his work on Python at the Corporation for
  National Research Initiatives (CNRI, see http://www.cnri.reston.va.us)
  in Reston, Virginia where he released several versions of the
  software.

  In May 2000, Guido and the Python core development team moved to
  BeOpen.com to form the BeOpen PythonLabs team.  In October of the same
  year, the PythonLabs team moved to Digital Creations (now Zope
  Corporation, see http://www.zope.com).  In 2001, the Python Software
  Foundation (PSF, see http://www.python.org/psf/) was formed, a
  non-profit organization created specifically to own Python-related
  Intellectual Property.  Zope Corporation is a sponsoring member of
  the PSF.

  All Python releases are Open Source (see http://www.opensource.org for
  the Open Source Definition).  Historically, most, but not all, Python
  releases have also been GPL-compatible; the table below summarizes
  the various releases.

      Release         Derived     Year        Owner       GPL-
                      from                                compatible? (1)

      0.9.0 thru 1.2              1991-1995   CWI         yes
      1.3 thru 1.5.2  1.2         1995-1999   CNRI        yes
      1.6             1.5.2       2000        CNRI        no
      2.0             1.6         2000        BeOpen.com  no
      1.6.1           1.6         2001        CNRI        yes (2)
      2.1             2.0+1.6.1   2001        PSF         no
      2.0.1           2.0+1.6.1   2001        PSF         yes
      2.1.1           2.1+2.0.1   2001        PSF         yes
      2.2             2.1.1       2001        PSF         yes
      2.1.2           2.1.1       2002        PSF         yes
      2.1.3           2.1.2       2002        PSF         yes
      2.2.1           2.2         2002        PSF         yes
      2.2.2           2.2.1       2002        PSF         yes
      2.2.3           2.2.2       2003        PSF         yes
      2.3             2.2.2       2002-2003   PSF         yes
      2.3.1           2.3         2002-2003   PSF         yes
      2.3.2           2.3.1       2002-2003   PSF         yes
      2.3.3           2.3.2       2002-2003   PSF         yes
      2.3.4           2.3.3       2004        PSF         yes
      2.3.5           2.3.4       2005        PSF         yes
      2.4             2.3         2004        PSF         yes
      2.4.1           2.4         2005        PSF         yes
      2.4.2           2.4.1       2005        PSF         yes
      2.4.3           2.4.2       2006        PSF         yes
      2.4.4           2.4.3       2006        PSF         yes
      2.5             2.4         2006        PSF         yes
      2.5.1           2.5         2007        PSF         yes
      2.5.2           2.5.1       2008        PSF         yes
      2.5.3           2.5.2       2008        PSF         yes
      2.6             2.5         2008        PSF         yes
      2.6.1           2.6         2008        PSF         yes

  Footnotes:

  (1) GPL-compatible doesn't mean that we're distributing Python under
      the GPL.  All Python licenses, unlike the GPL, let you distribute
      a modified version without making your changes open source.  The
      GPL-compatible licenses make it possible to combine Python with
      other software that is released under the GPL; the others don't.

  (2) According to Richard Stallman, 1.6.1 is not GPL-compatible,
      because its license has a choice of law clause.  According to
      CNRI, however, Stallman's lawyer has told CNRI's lawyer that 1.6.1
      is "not incompatible" with the GPL.

  Thanks to the many outside volunteers who have worked under Guido's
  direction to make these releases possible.


  B. TERMS AND CONDITIONS FOR ACCESSING OR OTHERWISE USING PYTHON
  ===============================================================

  PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
  --------------------------------------------

  1. This LICENSE AGREEMENT is between the Python Software Foundation
  ("PSF"), and the Individual or Organization ("Licensee") accessing and
  otherwise using this software ("Python") in source or binary form and
  its associated documentation.

  2. Subject to the terms and conditions of this License Agreement, PSF hereby
  grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce,
  analyze, test, perform and/or display publicly, prepare derivative works,
  distribute, and otherwise use Python alone or in any derivative version,
  provided, however, that PSF's License Agreement and PSF's notice of copyright,
  i.e., "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Python
  Software Foundation; All Rights Reserved" are retained in Python alone or in any
  derivative version prepared by Licensee.

  3. In the event Licensee prepares a derivative work that is based on
  or incorporates Python or any part thereof, and wants to make
  the derivative work available to others as provided herein, then
  Licensee hereby agrees to include in any such work a brief summary of
  the changes made to Python.

  4. PSF is making Python available to Licensee on an "AS IS"
  basis.  PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
  IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND
  DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
  FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON WILL NOT
  INFRINGE ANY THIRD PARTY RIGHTS.

  5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON
  FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS
  A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON,
  OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.

  6. This License Agreement will automatically terminate upon a material
  breach of its terms and conditions.

  7. Nothing in this License Agreement shall be deemed to create any
  relationship of agency, partnership, or joint venture between PSF and
  Licensee.  This License Agreement does not grant permission to use PSF
  trademarks or trade name in a trademark sense to endorse or promote
  products or services of Licensee, or any third party.

  8. By copying, installing or otherwise using Python, Licensee
  agrees to be bound by the terms and conditions of this License
  Agreement.


  BEOPEN.COM LICENSE AGREEMENT FOR PYTHON 2.0
  -------------------------------------------

  BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1

  1. This LICENSE AGREEMENT is between BeOpen.com ("BeOpen"), having an
  office at 160 Saratoga Avenue, Santa Clara, CA 95051, and the
  Individual or Organization ("Licensee") accessing and otherwise using
  this software in source or binary form and its associated
  documentation ("the Software").

  2. Subject to the terms and conditions of this BeOpen Python License
  Agreement, BeOpen hereby grants Licensee a non-exclusive,
  royalty-free, world-wide license to reproduce, analyze, test, perform
  and/or display publicly, prepare derivative works, distribute, and
  otherwise use the Software alone or in any derivative version,
  provided, however, that the BeOpen Python License is retained in the
  Software, alone or in any derivative version prepared by Licensee.

  3. BeOpen is making the Software available to Licensee on an "AS IS"
  basis.  BEOPEN MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
  IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, BEOPEN MAKES NO AND
  DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
  FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF THE SOFTWARE WILL NOT
  INFRINGE ANY THIRD PARTY RIGHTS.

  4. BEOPEN SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF THE
  SOFTWARE FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS
  AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THE SOFTWARE, OR ANY
  DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.

  5. This License Agreement will automatically terminate upon a material
  breach of its terms and conditions.

  6. This License Agreement shall be governed by and interpreted in all
  respects by the law of the State of California, excluding conflict of
  law provisions.  Nothing in this License Agreement shall be deemed to
  create any relationship of agency, partnership, or joint venture
  between BeOpen and Licensee.  This License Agreement does not grant
  permission to use BeOpen trademarks or trade names in a trademark
  sense to endorse or promote products or services of Licensee, or any
  third party.  As an exception, the "BeOpen Python" logos available at
  http://www.pythonlabs.com/logos.html may be used according to the
  permissions granted on that web page.

  7. By copying, installing or otherwise using the software, Licensee
  agrees to be bound by the terms and conditions of this License
  Agreement.


  CNRI LICENSE AGREEMENT FOR PYTHON 1.6.1
  ---------------------------------------

  1. This LICENSE AGREEMENT is between the Corporation for National
  Research Initiatives, having an office at 1895 Preston White Drive,
  Reston, VA 20191 ("CNRI"), and the Individual or Organization
  ("Licensee") accessing and otherwise using Python 1.6.1 software in
  source or binary form and its associated documentation.

  2. Subject to the terms and conditions of this License Agreement, CNRI
  hereby grants Licensee a nonexclusive, royalty-free, world-wide
  license to reproduce, analyze, test, perform and/or display publicly,
  prepare derivative works, distribute, and otherwise use Python 1.6.1
  alone or in any derivative version, provided, however, that CNRI's
  License Agreement and CNRI's notice of copyright, i.e., "Copyright (c)
  1995-2001 Corporation for National Research Initiatives; All Rights
  Reserved" are retained in Python 1.6.1 alone or in any derivative
  version prepared by Licensee.  Alternately, in lieu of CNRI's License
  Agreement, Licensee may substitute the following text (omitting the
  quotes): "Python 1.6.1 is made available subject to the terms and
  conditions in CNRI's License Agreement.  This Agreement together with
  Python 1.6.1 may be located on the Internet using the following
  unique, persistent identifier (known as a handle): 1895.22/1013.  This
  Agreement may also be obtained from a proxy server on the Internet
  using the following URL: http://hdl.handle.net/1895.22/1013".

  3. In the event Licensee prepares a derivative work that is based on
  or incorporates Python 1.6.1 or any part thereof, and wants to make
  the derivative work available to others as provided herein, then
  Licensee hereby agrees to include in any such work a brief summary of
  the changes made to Python 1.6.1.

  4. CNRI is making Python 1.6.1 available to Licensee on an "AS IS"
  basis.  CNRI MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
  IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, CNRI MAKES NO AND
  DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
  FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON 1.6.1 WILL NOT
  INFRINGE ANY THIRD PARTY RIGHTS.

  5. CNRI SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON
  1.6.1 FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS
  A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON 1.6.1,
  OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.

  6. This License Agreement will automatically terminate upon a material
  breach of its terms and conditions.

  7. This License Agreement shall be governed by the federal
  intellectual property law of the United States, including without
  limitation the federal copyright law, and, to the extent such
  U.S. federal law does not apply, by the law of the Commonwealth of
  Virginia, excluding Virginia's conflict of law provisions.
  Notwithstanding the foregoing, with regard to derivative works based
  on Python 1.6.1 that incorporate non-separable material that was
  previously distributed under the GNU General Public License (GPL), the
  law of the Commonwealth of Virginia shall govern this License
  Agreement only as to issues arising under or with respect to
  Paragraphs 4, 5, and 7 of this License Agreement.  Nothing in this
  License Agreement shall be deemed to create any relationship of
  agency, partnership, or joint venture between CNRI and Licensee.  This
  License Agreement does not grant permission to use CNRI trademarks or
  trade name in a trademark sense to endorse or promote products or
  services of Licensee, or any third party.

  8. By clicking on the "ACCEPT" button where indicated, or by copying,
  installing or otherwise using Python 1.6.1, Licensee agrees to be
  bound by the terms and conditions of this License Agreement.

          ACCEPT


  CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2
  --------------------------------------------------

  Copyright (c) 1991 - 1995, Stichting Mathematisch Centrum Amsterdam,
  The Netherlands.  All rights reserved.

  Permission to use, copy, modify, and distribute this software and its
  documentation for any purpose and without fee is hereby granted,
  provided that the above copyright notice appear in all copies and that
  both that copyright notice and this permission notice appear in
  supporting documentation, and that the name of Stichting Mathematisch
  Centrum or CWI not be used in advertising or publicity pertaining to
  distribution of the software without specific, written prior
  permission.

  STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
  THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
  FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
  FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

src/murmurhashneutral2.[hc]

This fast hash implementation is released to the public domain by Austin Appleby. See http://murmurhash.googlepages.com.

src/minitrace.[hc]

A library for producing JSON traces suitable for Chrome’s built-in trace viewer (chrome://tracing). Downloaded from https://github.com/hrydgard/minitrace.

The MIT License (MIT)

Copyright (c) 2014 Henrik RydgÄrd

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

src/snprintf.c and m4/snprintf.m4

This implementation of snprintf() and similar functions was downloaded from http://www.jhweiss.de/software/snprintf.html and has the following license:

  Copyright (c) 1995 Patrick Powell.

  This code is based on code written by Patrick Powell <papowell@astart.com>.
  It may be used for any purpose as long as this notice remains intact on all
  source code distributions.

  Copyright (c) 2008 Holger Weiss.

  This version of the code is maintained by Holger Weiss <holger@jhweiss.de>.
  My changes to the code may freely be used, modified and/or redistributed for
  any purpose. It would be nice if additions and fixes to this file (including
  trivial code cleanups) would be sent back in order to let me include them in
  the version available at <http://www.jhweiss.de/software/snprintf.html>.
  However, this is not a requirement for using or redistributing (possibly
  modified) versions of this file, nor is leaving this notice intact mandatory.

src/zlib/*.[hc]

This is a bundled subset of zlib 1.2.11 from http://zlib.net with the following license:

  Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.

  Jean-loup Gailly        Mark Adler
  jloup@gzip.org          madler@alumni.caltech.edu