[PATCH] [llvm] [Support] Update license on ConvertUTF.* per upstream license change

[mgorny]

Summary

According to [1], the author of the code found in ConvertUTF.* has
stated that the code has been relicensed to the standard Unicode license
as found on [2]. Update our copyright header appropriately, following
the same action done by Google breakpad maintainers [3].

Most importantly, the old license was non-free, effectively rendering
the whole LLVM distribution non-free. This is a major problem e.g. for
Debian [4], and has been also reported to LLVM Bugzilla [5]. I have
accidentally missed this license in Gentoo, and adding it will render
the package non-free which is going to cause real pain to some of our
users.

Sylvestre Ledru has already started working on porting LLVM to use
breakpad's version but apparently his work was stalled in regressions.
Since the issue is urgent, I am proposing instead to update the license
without porting other changes.

[1] https://bugs.chromium.org/p/google-breakpad/issues/detail?id=270
[2] https://www.unicode.org/copyright.html
[3] https://chromium.googlesource.com/breakpad/breakpad/+/14bbefbd9600e08d6a34d7250faa8bc9dba2113e
[4] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=916945
[5] https://bugs.llvm.org/show_bug.cgi?id=32962

[sylvestre.ledru]

I don't think we can unilaterally update the license. Especially as the new code is different.
My change need some work (summer doesn't help). The testsuites work, the unit tests on this file don't.

[sylvestre.ledru]

And it isnt really urgent as it has been this way for years now

[sylvestre.ledru]

My change is https://reviews.llvm.org/D64740

[mgorny]

As I've noted on D64740, the code in breakpad is identical (except for ordering and whitespace changes) to our initial code. All code differences between us and breakpad are our local changes. Therefore, I think we can change the license in place. If you really insist, I can reorder the functions match ordering in breakpad, and do some whitespace changes ;-).

[sylvestre.ledru]

@chandlerc What do you think? thanks!

[mgorny]

Ping.

[mgorny]

Reping.

[mgorny]

Ping.

[mgorny]

Some more ping.

[mgorny]

Ping.

[sylvestre.ledru]

I would like to see that happening but I am not a lawyer and important enough person in the project to make such call.

With my experience with license (ex: iceweasel vs firefox), I am sure that @chandlerc isn't ignoring you, just that he cannot answer about this subject.

[jyknight]

Indeed, legal issues are complicated.

Looking into this today, I'm personally fairly confident this code is indeed re-licensed and that, therefore, this change is OK. I say that based on analysis as follows:

1. https://web.archive.org/web/20080831201118/http://www.unicode.org/copyright.html (archived 2008-08-31) has the new license text in place, and says it applies to all source code distributed under http://www.unicode.org/Public/.
2. You can find the ConvertUTF.c and ConvertUTF.h files at https://web.archive.org/web/20080913080605/http://www.unicode.org:80/Public/PROGRAMS/CVTUTF/ (archive link as of 2008-09-13, but file content unchanged since 2004). That is: they were being distributed, then, under this "new" license. Note that the files were subsequently deleted, in 2009, due to being buggy and unmaintained -- so you cannot find them on unicode.org today.
3. LLVM's initial commit of these files (https://github.com/llvm/llvm-project/commit/29cae66bde8b9d1694d85e6fa43fcf5a3ab46e2d) contains files derived -- with only LLVM-side changes -- from the version of the software distributed in that link.

I'm not giving an "Approval" to commit this change yet, though -- I believe LLVM Foundation lawyer will be double-checking this is a correct action, first.

[tonic]

After legal consult, The LLVM Foundation board is ok with the change to the license on these files.

llvm/include/llvm/Support/ConvertUTF.h

 /*===--- ConvertUTF.h - Universal Character Names conversions ---------------===
  *
  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  * See https://llvm.org/LICENSE.txt for license information.
  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  *
  *==------------------------------------------------------------------------==*/
 /*
- * Copyright 2001-2004 Unicode, Inc.
- *
- * Disclaimer
- *
- * This source code is provided as is by Unicode, Inc. No claims are
- * made as to fitness for any particular purpose. No warranties of any
- * kind are expressed or implied. The recipient agrees to determine
- * applicability of information provided. If this file has been
- * purchased on magnetic or optical media from Unicode, Inc., the
- * sole remedy for any claim will be exchange of defective media
- * within 90 days of receipt.
- *
- * Limitations on Rights to Redistribute This Code
- *
- * Unicode, Inc. hereby grants the right to freely use the information
- * supplied in this file in the creation of products supporting the
- * Unicode Standard, and to make copies of this file in any form
- * for internal or external distribution as long as this notice
- * remains attached.
+ * Copyright © 1991-2015 Unicode, Inc. All rights reserved.
+ * Distributed under the Terms of Use in
+ * http://www.unicode.org/copyright.html.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of the Unicode data files and any associated documentation
+ * (the "Data Files") or Unicode software and any associated documentation
+ * (the "Software") to deal in the Data Files or Software
+ * without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, and/or sell copies of
+ * the Data Files or Software, and to permit persons to whom the Data Files
+ * or Software are furnished to do so, provided that
+ * (a) this copyright and permission notice appear with all copies
+ * of the Data Files or Software,
+ * (b) this copyright and permission notice appear in associated
+ * documentation, and
+ * (c) there is clear notice in each modified Data File or in the Software
+ * as well as in the documentation associated with the Data File(s) or
+ * Software that the data or software has been modified.
+ *
+ * THE DATA FILES AND SOFTWARE ARE 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 OF THIRD PARTY RIGHTS.
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS
+ * NOTICE BE LIABLE FOR ANY CLAIM, OR 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 THE DATA FILES OR SOFTWARE.
+ *
+ * Except as contained in this notice, the name of a copyright holder
+ * shall not be used in advertising or otherwise to promote the sale,
+ * use or other dealings in these Data Files or Software without prior
+ * written authorization of the copyright holder.
  */
 
 /* ---------------------------------------------------------------------
 
     Conversions between UTF32, UTF-16, and UTF-8.  Header file.
 
     Several funtions are included here, forming a complete set of
     conversions between the three formats.  UTF-7 is not included

llvm/lib/Support/ConvertUTF.cpp

 /*===--- ConvertUTF.c - Universal Character Names conversions ---------------===
  *
  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  * See https://llvm.org/LICENSE.txt for license information.
  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  *
  *===------------------------------------------------------------------------=*/
 /*
- * Copyright 2001-2004 Unicode, Inc.
+ * Copyright © 1991-2015 Unicode, Inc. All rights reserved.
+ * Distributed under the Terms of Use in
+ * http://www.unicode.org/copyright.html.
  *
- * Disclaimer
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of the Unicode data files and any associated documentation
+ * (the "Data Files") or Unicode software and any associated documentation
+ * (the "Software") to deal in the Data Files or Software
+ * without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, and/or sell copies of
+ * the Data Files or Software, and to permit persons to whom the Data Files
+ * or Software are furnished to do so, provided that
+ * (a) this copyright and permission notice appear with all copies
+ * of the Data Files or Software,
+ * (b) this copyright and permission notice appear in associated
+ * documentation, and
+ * (c) there is clear notice in each modified Data File or in the Software
+ * as well as in the documentation associated with the Data File(s) or
+ * Software that the data or software has been modified.
  *
- * This source code is provided as is by Unicode, Inc. No claims are
- * made as to fitness for any particular purpose. No warranties of any
- * kind are expressed or implied. The recipient agrees to determine
- * applicability of information provided. If this file has been
- * purchased on magnetic or optical media from Unicode, Inc., the
- * sole remedy for any claim will be exchange of defective media
- * within 90 days of receipt.
+ * THE DATA FILES AND SOFTWARE ARE 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 OF THIRD PARTY RIGHTS.
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS
+ * NOTICE BE LIABLE FOR ANY CLAIM, OR 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 THE DATA FILES OR SOFTWARE.
  *
- * Limitations on Rights to Redistribute This Code
- *
- * Unicode, Inc. hereby grants the right to freely use the information
- * supplied in this file in the creation of products supporting the
- * Unicode Standard, and to make copies of this file in any form
- * for internal or external distribution as long as this notice
- * remains attached.
+ * Except as contained in this notice, the name of a copyright holder
+ * shall not be used in advertising or otherwise to promote the sale,
+ * use or other dealings in these Data Files or Software without prior
+ * written authorization of the copyright holder.
  */
 
 /* ---------------------------------------------------------------------
 
     Conversions between UTF32, UTF-16, and UTF-8. Source code file.
     Author: Mark E. Davis, 1994.
     Rev History: Rick McGowan, fixes & updates May 2001.
     Sept 2001: fixed const & error conditions per