##// END OF EJS Templates
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.

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zstd_common.c
83 lines | 2.6 KiB | text/x-c | CLexer
/*
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
/*-*************************************
* Dependencies
***************************************/
#include <stdlib.h> /* malloc, calloc, free */
#include <string.h> /* memset */
#include "error_private.h"
#include "zstd_internal.h"
/*-****************************************
* Version
******************************************/
unsigned ZSTD_versionNumber(void) { return ZSTD_VERSION_NUMBER; }
const char* ZSTD_versionString(void) { return ZSTD_VERSION_STRING; }
/*-****************************************
* ZSTD Error Management
******************************************/
#undef ZSTD_isError /* defined within zstd_internal.h */
/*! ZSTD_isError() :
* tells if a return value is an error code
* symbol is required for external callers */
unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
/*! ZSTD_getErrorName() :
* provides error code string from function result (useful for debugging) */
const char* ZSTD_getErrorName(size_t code) { return ERR_getErrorName(code); }
/*! ZSTD_getError() :
* convert a `size_t` function result into a proper ZSTD_errorCode enum */
ZSTD_ErrorCode ZSTD_getErrorCode(size_t code) { return ERR_getErrorCode(code); }
/*! ZSTD_getErrorString() :
* provides error code string from enum */
const char* ZSTD_getErrorString(ZSTD_ErrorCode code) { return ERR_getErrorString(code); }
/*=**************************************************************
* Custom allocator
****************************************************************/
void* ZSTD_malloc(size_t size, ZSTD_customMem customMem)
{
if (customMem.customAlloc)
return customMem.customAlloc(customMem.opaque, size);
return malloc(size);
}
void* ZSTD_calloc(size_t size, ZSTD_customMem customMem)
{
if (customMem.customAlloc) {
/* calloc implemented as malloc+memset;
* not as efficient as calloc, but next best guess for custom malloc */
void* const ptr = customMem.customAlloc(customMem.opaque, size);
memset(ptr, 0, size);
return ptr;
}
return calloc(1, size);
}
void ZSTD_free(void* ptr, ZSTD_customMem customMem)
{
if (ptr!=NULL) {
if (customMem.customFree)
customMem.customFree(customMem.opaque, ptr);
else
free(ptr);
}
}