upstream/mercurial-mirror Files · contrib/python-zstandard/zstd/common/debug.c

rust-cpython: mark all PyLeaked methods as unsafe...

rust-cpython: mark all PyLeaked methods as unsafe Unfortunately, these methods can be abused to obtain the inner 'static reference. The simplest (pseudo-code) example is: let leaked: PyLeaked<&'static _> = shared.leak_immutable(); let static_ref: &'static _ = &*leaked.try_borrow(py)?; // PyLeakedRef::deref() tries to bound the lifetime to itself, but // the underlying data is a &'static reference, so the returned // reference can be &'static. This problem can be easily fixed by coercing the lifetime, but there are many other ways to achieve that, and there wouldn't be a generic solution: let leaked: PyLeaked<&'static [_]> = shared.leak_immutable(); let leaked_iter: PyLeaked<slice::Iter<'static, _>> = unsafe { leaked.map(|v| v.iter()) }; let static_slice: &'static [_] = leaked_iter.try_borrow(py)?.as_slice(); So basically I failed to design the safe borrowing interface. Maybe we'll instead have to add much more restricted interface on top of the unsafe PyLeaked methods? For instance, Iterator::next() could be implemented if its Item type is not &'a (where 'a may be cheated.) Anyway, this seems not an easy issue, so it's probably better to leave the current interface as unsafe, and get broader comments while upstreaming this feature.

Gregory Szorc - - Load All Authors

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      /* ******************************************************************

         debug

         Part of FSE library

         Copyright (C) 2013-present, Yann Collet.

         BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)

         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.

         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.

         You can contact the author at :

         - Source repository : https://github.com/Cyan4973/FiniteStateEntropy

      ****************************************************************** */

      /*

       * This module only hosts one global variable

       * which can be used to dynamically influence the verbosity of traces,

       * such as DEBUGLOG and RAWLOG

       */

      #include "debug.h"

      int g_debuglevel = DEBUGLEVEL;

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				/* ******************************************************************
				debug
				Part of FSE library
				Copyright (C) 2013-present, Yann Collet.

				BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)

				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.

				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.

				You can contact the author at :
				- Source repository : https://github.com/Cyan4973/FiniteStateEntropy
				****************************************************************** */


				/*
				* This module only hosts one global variable
				* which can be used to dynamically influence the verbosity of traces,
				* such as DEBUGLOG and RAWLOG
				*/

				#include "debug.h"

				int g_debuglevel = DEBUGLEVEL;