Files
llvm/libcxx/include/__debug
Louis Dionne f3966eaf86 [libc++] Make the Debug mode a configuration-time only option
The debug mode has been broken pretty much ever since it was shipped
because it was possible to enable the debug mode in user code without
actually enabling it in the dylib, leading to ODR violations that
caused various kinds of failures.

This commit makes the debug mode a knob that is configured when
building the library and which can't be changed afterwards. This is
less flexible for users, however it will actually work as intended
and it will allow us, in the future, to add various kinds of checks
that do not assume the same ABI as the normal library. Furthermore,
this will make the debug mode more robust, which means that vendors
might be more tempted to support it properly, which hasn't been the
case with the current debug mode.

This patch shouldn't break any user code, except folks who are building
against a library that doesn't have the debug mode enabled and who try
to enable the debug mode in their code. Such users will get a compile-time
error explaining that this configuration isn't supported anymore.

In the future, we should further increase the granularity of the debug
mode checks so that we can cherry-pick which checks to enable, like we
do for unspecified behavior randomization.

Differential Revision: https://reviews.llvm.org/D122941
2022-06-07 16:33:53 -04:00

287 lines
8.5 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___DEBUG
#define _LIBCPP___DEBUG
#include <__assert>
#include <__config>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
// Catch invalid uses of the legacy _LIBCPP_DEBUG toggle.
#if defined(_LIBCPP_DEBUG) && _LIBCPP_DEBUG != 0 && !defined(_LIBCPP_ENABLE_DEBUG_MODE)
# error "Enabling the debug mode now requires having configured the library with support for the debug mode"
#endif
#if defined(_LIBCPP_ENABLE_DEBUG_MODE) && !defined(_LIBCPP_CXX03_LANG) && !defined(_LIBCPP_DEBUG_RANDOMIZE_UNSPECIFIED_STABILITY)
# define _LIBCPP_DEBUG_RANDOMIZE_UNSPECIFIED_STABILITY
#endif
// TODO: Define this as a function instead
#if defined(_LIBCPP_DEBUG_RANDOMIZE_UNSPECIFIED_STABILITY)
# if defined(_LIBCPP_CXX03_LANG)
# error Support for unspecified stability is only for C++11 and higher
# endif
# define _LIBCPP_DEBUG_RANDOMIZE_RANGE(__first, __last) \
do { \
if (!__builtin_is_constant_evaluated()) \
std::shuffle(__first, __last, __libcpp_debug_randomizer()); \
} while (false)
#else
# define _LIBCPP_DEBUG_RANDOMIZE_RANGE(__first, __last) \
do { \
} while (false)
#endif
#ifdef _LIBCPP_ENABLE_DEBUG_MODE
# define _LIBCPP_DEBUG_ASSERT(x, m) _LIBCPP_ASSERT(::std::__libcpp_is_constant_evaluated() || (x), m)
#else
# define _LIBCPP_DEBUG_ASSERT(x, m) ((void)0)
#endif
#if defined(_LIBCPP_ENABLE_DEBUG_MODE) || defined(_LIBCPP_BUILDING_LIBRARY)
#include <cstddef>
#include <cstdio>
#include <cstdlib>
_LIBCPP_BEGIN_NAMESPACE_STD
struct _LIBCPP_TYPE_VIS __c_node;
struct _LIBCPP_TYPE_VIS __i_node
{
void* __i_;
__i_node* __next_;
__c_node* __c_;
__i_node(const __i_node&) = delete;
__i_node& operator=(const __i_node&) = delete;
_LIBCPP_INLINE_VISIBILITY
__i_node(void* __i, __i_node* __next, __c_node* __c)
: __i_(__i), __next_(__next), __c_(__c) {}
~__i_node();
};
struct _LIBCPP_TYPE_VIS __c_node
{
void* __c_;
__c_node* __next_;
__i_node** beg_;
__i_node** end_;
__i_node** cap_;
__c_node(const __c_node&) = delete;
__c_node& operator=(const __c_node&) = delete;
_LIBCPP_INLINE_VISIBILITY
explicit __c_node(void* __c, __c_node* __next)
: __c_(__c), __next_(__next), beg_(nullptr), end_(nullptr), cap_(nullptr) {}
virtual ~__c_node();
virtual bool __dereferenceable(const void*) const = 0;
virtual bool __decrementable(const void*) const = 0;
virtual bool __addable(const void*, ptrdiff_t) const = 0;
virtual bool __subscriptable(const void*, ptrdiff_t) const = 0;
void __add(__i_node* __i);
_LIBCPP_HIDDEN void __remove(__i_node* __i);
};
template <class _Cont>
struct _C_node
: public __c_node
{
explicit _C_node(void* __c, __c_node* __n)
: __c_node(__c, __n) {}
virtual bool __dereferenceable(const void*) const;
virtual bool __decrementable(const void*) const;
virtual bool __addable(const void*, ptrdiff_t) const;
virtual bool __subscriptable(const void*, ptrdiff_t) const;
};
template <class _Cont>
inline bool
_C_node<_Cont>::__dereferenceable(const void* __i) const
{
typedef typename _Cont::const_iterator iterator;
const iterator* __j = static_cast<const iterator*>(__i);
_Cont* _Cp = static_cast<_Cont*>(__c_);
return _Cp->__dereferenceable(__j);
}
template <class _Cont>
inline bool
_C_node<_Cont>::__decrementable(const void* __i) const
{
typedef typename _Cont::const_iterator iterator;
const iterator* __j = static_cast<const iterator*>(__i);
_Cont* _Cp = static_cast<_Cont*>(__c_);
return _Cp->__decrementable(__j);
}
template <class _Cont>
inline bool
_C_node<_Cont>::__addable(const void* __i, ptrdiff_t __n) const
{
typedef typename _Cont::const_iterator iterator;
const iterator* __j = static_cast<const iterator*>(__i);
_Cont* _Cp = static_cast<_Cont*>(__c_);
return _Cp->__addable(__j, __n);
}
template <class _Cont>
inline bool
_C_node<_Cont>::__subscriptable(const void* __i, ptrdiff_t __n) const
{
typedef typename _Cont::const_iterator iterator;
const iterator* __j = static_cast<const iterator*>(__i);
_Cont* _Cp = static_cast<_Cont*>(__c_);
return _Cp->__subscriptable(__j, __n);
}
class _LIBCPP_TYPE_VIS __libcpp_db
{
__c_node** __cbeg_;
__c_node** __cend_;
size_t __csz_;
__i_node** __ibeg_;
__i_node** __iend_;
size_t __isz_;
explicit __libcpp_db();
public:
__libcpp_db(const __libcpp_db&) = delete;
__libcpp_db& operator=(const __libcpp_db&) = delete;
~__libcpp_db();
class __db_c_iterator;
class __db_c_const_iterator;
class __db_i_iterator;
class __db_i_const_iterator;
__db_c_const_iterator __c_end() const;
__db_i_const_iterator __i_end() const;
typedef __c_node*(_InsertConstruct)(void*, void*, __c_node*);
template <class _Cont>
_LIBCPP_INLINE_VISIBILITY static __c_node* __create_C_node(void *__mem, void *__c, __c_node *__next) {
return ::new (__mem) _C_node<_Cont>(__c, __next);
}
template <class _Cont>
_LIBCPP_INLINE_VISIBILITY
void __insert_c(_Cont* __c)
{
__insert_c(static_cast<void*>(__c), &__create_C_node<_Cont>);
}
void __insert_i(void* __i);
void __insert_c(void* __c, _InsertConstruct* __fn);
void __erase_c(void* __c);
void __insert_ic(void* __i, const void* __c);
void __iterator_copy(void* __i, const void* __i0);
void __erase_i(void* __i);
void* __find_c_from_i(void* __i) const;
void __invalidate_all(void* __c);
__c_node* __find_c_and_lock(void* __c) const;
__c_node* __find_c(void* __c) const;
void unlock() const;
void swap(void* __c1, void* __c2);
bool __dereferenceable(const void* __i) const;
bool __decrementable(const void* __i) const;
bool __addable(const void* __i, ptrdiff_t __n) const;
bool __subscriptable(const void* __i, ptrdiff_t __n) const;
bool __less_than_comparable(const void* __i, const void* __j) const;
private:
_LIBCPP_HIDDEN
__i_node* __insert_iterator(void* __i);
_LIBCPP_HIDDEN
__i_node* __find_iterator(const void* __i) const;
friend _LIBCPP_FUNC_VIS __libcpp_db* __get_db();
};
_LIBCPP_FUNC_VIS __libcpp_db* __get_db();
_LIBCPP_FUNC_VIS const __libcpp_db* __get_const_db();
_LIBCPP_END_NAMESPACE_STD
#endif // defined(_LIBCPP_ENABLE_DEBUG_MODE) || defined(_LIBCPP_BUILDING_LIBRARY)
_LIBCPP_BEGIN_NAMESPACE_STD
template <class _Tp>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 inline void __debug_db_insert_c(_Tp* __c) {
#ifdef _LIBCPP_ENABLE_DEBUG_MODE
if (!__libcpp_is_constant_evaluated())
__get_db()->__insert_c(__c);
#else
(void)(__c);
#endif
}
template <class _Tp>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 inline void __debug_db_insert_i(_Tp* __i) {
#ifdef _LIBCPP_ENABLE_DEBUG_MODE
if (!__libcpp_is_constant_evaluated())
__get_db()->__insert_i(__i);
#else
(void)(__i);
#endif
}
template <class _Tp>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 inline void __debug_db_erase_c(_Tp* __c) {
#ifdef _LIBCPP_ENABLE_DEBUG_MODE
if (!__libcpp_is_constant_evaluated())
__get_db()->__erase_c(__c);
#else
(void)(__c);
#endif
}
template <class _Tp>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 inline void __debug_db_swap(_Tp* __lhs, _Tp* __rhs) {
#ifdef _LIBCPP_ENABLE_DEBUG_MODE
if (!__libcpp_is_constant_evaluated())
__get_db()->swap(__lhs, __rhs);
#else
(void)(__lhs);
(void)(__rhs);
#endif
}
template <class _Tp>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 inline void __debug_db_invalidate_all(_Tp* __c) {
#ifdef _LIBCPP_ENABLE_DEBUG_MODE
if (!__libcpp_is_constant_evaluated())
__get_db()->__invalidate_all(__c);
#else
(void)(__c);
#endif
}
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___DEBUG