227 lines
8.7 KiB
C
227 lines
8.7 KiB
C
/* ATTRIBUTE_* macros for using attributes in GCC and similar compilers
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Copyright 2020-2023 Free Software Foundation, Inc.
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This file is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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This file is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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/* Written by Paul Eggert. */
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/* Provide public ATTRIBUTE_* names for the private _GL_ATTRIBUTE_*
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macros used within Gnulib. */
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/* These attributes can be placed in two ways:
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- At the start of a declaration (i.e. even before storage-class
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specifiers!); then they apply to all entities that are declared
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by the declaration.
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- Immediately after the name of an entity being declared by the
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declaration; then they apply to that entity only. */
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#ifndef _GL_ATTRIBUTE_H
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#define _GL_ATTRIBUTE_H
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/* This file defines two types of attributes:
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* C23 standard attributes. These have macro names that do not begin with
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'ATTRIBUTE_'.
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* Selected GCC attributes; see:
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https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html
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https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html
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https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html
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These names begin with 'ATTRIBUTE_' to avoid name clashes. */
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/* =============== Attributes for specific kinds of functions =============== */
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/* Attributes for functions that should not be used. */
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/* Warn if the entity is used. */
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/* Applies to:
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- function, variable,
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- struct, union, struct/union member,
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- enumeration, enumeration item,
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- typedef,
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in C++ also: namespace, class, template specialization. */
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#define DEPRECATED _GL_ATTRIBUTE_DEPRECATED
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/* If a function call is not optimized way, warn with MSG. */
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/* Applies to: functions. */
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#define ATTRIBUTE_WARNING(msg) _GL_ATTRIBUTE_WARNING (msg)
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/* If a function call is not optimized way, report an error with MSG. */
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/* Applies to: functions. */
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#define ATTRIBUTE_ERROR(msg) _GL_ATTRIBUTE_ERROR (msg)
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/* Attributes for memory-allocating functions. */
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/* The function returns a pointer to freshly allocated memory. */
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/* Applies to: functions. */
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#define ATTRIBUTE_MALLOC _GL_ATTRIBUTE_MALLOC
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/* ATTRIBUTE_ALLOC_SIZE ((N)) - The Nth argument of the function
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is the size of the returned memory block.
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ATTRIBUTE_ALLOC_SIZE ((M, N)) - Multiply the Mth and Nth arguments
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to determine the size of the returned memory block. */
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/* Applies to: function, pointer to function, function types. */
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#define ATTRIBUTE_ALLOC_SIZE(args) _GL_ATTRIBUTE_ALLOC_SIZE (args)
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/* ATTRIBUTE_DEALLOC (F, I) declares that the function returns pointers
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that can be freed by passing them as the Ith argument to the
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function F.
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ATTRIBUTE_DEALLOC_FREE declares that the function returns pointers that
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can be freed via 'free'; it can be used only after declaring 'free'. */
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/* Applies to: functions. Cannot be used on inline functions. */
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#define ATTRIBUTE_DEALLOC(f, i) _GL_ATTRIBUTE_DEALLOC(f, i)
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#define ATTRIBUTE_DEALLOC_FREE _GL_ATTRIBUTE_DEALLOC_FREE
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/* Attributes for variadic functions. */
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/* The variadic function expects a trailing NULL argument.
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ATTRIBUTE_SENTINEL () - The last argument is NULL (requires C99).
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ATTRIBUTE_SENTINEL ((N)) - The (N+1)st argument from the end is NULL. */
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/* Applies to: functions. */
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#define ATTRIBUTE_SENTINEL(pos) _GL_ATTRIBUTE_SENTINEL (pos)
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/* ================== Attributes for compiler diagnostics ================== */
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/* Attributes that help the compiler diagnose programmer mistakes.
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Some of them may also help for some compiler optimizations. */
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/* ATTRIBUTE_FORMAT ((ARCHETYPE, STRING-INDEX, FIRST-TO-CHECK)) -
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The STRING-INDEXth function argument is a format string of style
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ARCHETYPE, which is one of:
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printf, gnu_printf
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scanf, gnu_scanf,
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strftime, gnu_strftime,
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strfmon,
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or the same thing prefixed and suffixed with '__'.
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If FIRST-TO-CHECK is not 0, arguments starting at FIRST-TO_CHECK
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are suitable for the format string. */
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/* Applies to: functions. */
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#define ATTRIBUTE_FORMAT(spec) _GL_ATTRIBUTE_FORMAT (spec)
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/* ATTRIBUTE_NONNULL ((N1, N2,...)) - Arguments N1, N2,... must not be NULL.
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ATTRIBUTE_NONNULL () - All pointer arguments must not be null. */
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/* Applies to: functions. */
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#define ATTRIBUTE_NONNULL(args) _GL_ATTRIBUTE_NONNULL (args)
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/* The function's return value is a non-NULL pointer. */
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/* Applies to: functions. */
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#define ATTRIBUTE_RETURNS_NONNULL _GL_ATTRIBUTE_RETURNS_NONNULL
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/* Warn if the caller does not use the return value,
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unless the caller uses something like ignore_value. */
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/* Applies to: function, enumeration, class. */
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#define NODISCARD _GL_ATTRIBUTE_NODISCARD
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/* Attributes that disable false alarms when the compiler diagnoses
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programmer "mistakes". */
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/* Do not warn if the entity is not used. */
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/* Applies to:
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- function, variable,
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- struct, union, struct/union member,
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- enumeration, enumeration item,
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- typedef,
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in C++ also: class. */
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#define MAYBE_UNUSED _GL_ATTRIBUTE_MAYBE_UNUSED
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/* The contents of a character array is not meant to be NUL-terminated. */
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/* Applies to: struct/union members and variables that are arrays of element
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type '[[un]signed] char'. */
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#define ATTRIBUTE_NONSTRING _GL_ATTRIBUTE_NONSTRING
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/* Do not warn if control flow falls through to the immediately
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following 'case' or 'default' label. */
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/* Applies to: Empty statement (;), inside a 'switch' statement. */
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#define FALLTHROUGH _GL_ATTRIBUTE_FALLTHROUGH
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/* ================== Attributes for debugging information ================== */
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/* Attributes regarding debugging information emitted by the compiler. */
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/* Omit the function from stack traces when debugging. */
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/* Applies to: function. */
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#define ATTRIBUTE_ARTIFICIAL _GL_ATTRIBUTE_ARTIFICIAL
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/* Make the entity visible to debuggers etc., even with '-fwhole-program'. */
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/* Applies to: functions, variables. */
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#define ATTRIBUTE_EXTERNALLY_VISIBLE _GL_ATTRIBUTE_EXTERNALLY_VISIBLE
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/* ========== Attributes that mainly direct compiler optimizations ========== */
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/* The function does not throw exceptions. */
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/* Applies to: functions. */
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#define ATTRIBUTE_NOTHROW _GL_ATTRIBUTE_NOTHROW
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/* Do not inline the function. */
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/* Applies to: functions. */
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#define ATTRIBUTE_NOINLINE _GL_ATTRIBUTE_NOINLINE
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/* Always inline the function, and report an error if the compiler
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cannot inline. */
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/* Applies to: function. */
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#define ATTRIBUTE_ALWAYS_INLINE _GL_ATTRIBUTE_ALWAYS_INLINE
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/* It is OK for a compiler to omit duplicate calls with the same arguments.
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This attribute is safe for a function that neither depends on
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nor affects observable state, and always returns exactly once -
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e.g., does not loop forever, and does not call longjmp.
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(This attribute is stricter than ATTRIBUTE_PURE.) */
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/* Applies to: functions. */
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#define ATTRIBUTE_CONST _GL_ATTRIBUTE_CONST
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/* It is OK for a compiler to omit duplicate calls with the same
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arguments if observable state is not changed between calls.
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This attribute is safe for a function that does not affect
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observable state, and always returns exactly once.
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(This attribute is looser than ATTRIBUTE_CONST.) */
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/* Applies to: functions. */
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#define ATTRIBUTE_PURE _GL_ATTRIBUTE_PURE
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/* The function is rarely executed. */
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/* Applies to: functions. */
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#define ATTRIBUTE_COLD _GL_ATTRIBUTE_COLD
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/* If called from some other compilation unit, the function executes
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code from that unit only by return or by exception handling,
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letting the compiler optimize that unit more aggressively. */
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/* Applies to: functions. */
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#define ATTRIBUTE_LEAF _GL_ATTRIBUTE_LEAF
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/* For struct members: The member has the smallest possible alignment.
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For struct, union, class: All members have the smallest possible alignment,
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minimizing the memory required. */
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/* Applies to: struct members, struct, union,
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in C++ also: class. */
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#define ATTRIBUTE_PACKED _GL_ATTRIBUTE_PACKED
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/* ================ Attributes that make invalid code valid ================ */
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/* Attributes that prevent fatal compiler optimizations for code that is not
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fully ISO C compliant. */
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/* Pointers to the type may point to the same storage as pointers to
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other types, thus disabling strict aliasing optimization. */
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/* Applies to: types. */
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#define ATTRIBUTE_MAY_ALIAS _GL_ATTRIBUTE_MAY_ALIAS
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#endif /* _GL_ATTRIBUTE_H */
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