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| -rw-r--r-- | lib/attribute.h | 226 |
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diff --git a/lib/attribute.h b/lib/attribute.h new file mode 100644 index 0000000..130644d --- /dev/null +++ b/lib/attribute.h @@ -0,0 +1,226 @@ +/* ATTRIBUTE_* macros for using attributes in GCC and similar compilers + + Copyright 2020-2023 Free Software Foundation, Inc. + + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + This file is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* Written by Paul Eggert. */ + +/* Provide public ATTRIBUTE_* names for the private _GL_ATTRIBUTE_* + macros used within Gnulib. */ + +/* These attributes can be placed in two ways: + - At the start of a declaration (i.e. even before storage-class + specifiers!); then they apply to all entities that are declared + by the declaration. + - Immediately after the name of an entity being declared by the + declaration; then they apply to that entity only. */ + +#ifndef _GL_ATTRIBUTE_H +#define _GL_ATTRIBUTE_H + + +/* This file defines two types of attributes: + * C23 standard attributes. These have macro names that do not begin with + 'ATTRIBUTE_'. + * Selected GCC attributes; see: + https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html + https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html + https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html + These names begin with 'ATTRIBUTE_' to avoid name clashes. */ + + +/* =============== Attributes for specific kinds of functions =============== */ + +/* Attributes for functions that should not be used. */ + +/* Warn if the entity is used. */ +/* Applies to: + - function, variable, + - struct, union, struct/union member, + - enumeration, enumeration item, + - typedef, + in C++ also: namespace, class, template specialization. */ +#define DEPRECATED _GL_ATTRIBUTE_DEPRECATED + +/* If a function call is not optimized way, warn with MSG. */ +/* Applies to: functions. */ +#define ATTRIBUTE_WARNING(msg) _GL_ATTRIBUTE_WARNING (msg) + +/* If a function call is not optimized way, report an error with MSG. */ +/* Applies to: functions. */ +#define ATTRIBUTE_ERROR(msg) _GL_ATTRIBUTE_ERROR (msg) + + +/* Attributes for memory-allocating functions. */ + +/* The function returns a pointer to freshly allocated memory. */ +/* Applies to: functions. */ +#define ATTRIBUTE_MALLOC _GL_ATTRIBUTE_MALLOC + +/* ATTRIBUTE_ALLOC_SIZE ((N)) - The Nth argument of the function + is the size of the returned memory block. + ATTRIBUTE_ALLOC_SIZE ((M, N)) - Multiply the Mth and Nth arguments + to determine the size of the returned memory block. */ +/* Applies to: function, pointer to function, function types. */ +#define ATTRIBUTE_ALLOC_SIZE(args) _GL_ATTRIBUTE_ALLOC_SIZE (args) + +/* ATTRIBUTE_DEALLOC (F, I) declares that the function returns pointers + that can be freed by passing them as the Ith argument to the + function F. + ATTRIBUTE_DEALLOC_FREE declares that the function returns pointers that + can be freed via 'free'; it can be used only after declaring 'free'. */ +/* Applies to: functions. Cannot be used on inline functions. */ +#define ATTRIBUTE_DEALLOC(f, i) _GL_ATTRIBUTE_DEALLOC(f, i) +#define ATTRIBUTE_DEALLOC_FREE _GL_ATTRIBUTE_DEALLOC_FREE + +/* Attributes for variadic functions. */ + +/* The variadic function expects a trailing NULL argument. + ATTRIBUTE_SENTINEL () - The last argument is NULL (requires C99). + ATTRIBUTE_SENTINEL ((N)) - The (N+1)st argument from the end is NULL. */ +/* Applies to: functions. */ +#define ATTRIBUTE_SENTINEL(pos) _GL_ATTRIBUTE_SENTINEL (pos) + + +/* ================== Attributes for compiler diagnostics ================== */ + +/* Attributes that help the compiler diagnose programmer mistakes. + Some of them may also help for some compiler optimizations. */ + +/* ATTRIBUTE_FORMAT ((ARCHETYPE, STRING-INDEX, FIRST-TO-CHECK)) - + The STRING-INDEXth function argument is a format string of style + ARCHETYPE, which is one of: + printf, gnu_printf + scanf, gnu_scanf, + strftime, gnu_strftime, + strfmon, + or the same thing prefixed and suffixed with '__'. + If FIRST-TO-CHECK is not 0, arguments starting at FIRST-TO_CHECK + are suitable for the format string. */ +/* Applies to: functions. */ +#define ATTRIBUTE_FORMAT(spec) _GL_ATTRIBUTE_FORMAT (spec) + +/* ATTRIBUTE_NONNULL ((N1, N2,...)) - Arguments N1, N2,... must not be NULL. + ATTRIBUTE_NONNULL () - All pointer arguments must not be null. */ +/* Applies to: functions. */ +#define ATTRIBUTE_NONNULL(args) _GL_ATTRIBUTE_NONNULL (args) + +/* The function's return value is a non-NULL pointer. */ +/* Applies to: functions. */ +#define ATTRIBUTE_RETURNS_NONNULL _GL_ATTRIBUTE_RETURNS_NONNULL + +/* Warn if the caller does not use the return value, + unless the caller uses something like ignore_value. */ +/* Applies to: function, enumeration, class. */ +#define NODISCARD _GL_ATTRIBUTE_NODISCARD + + +/* Attributes that disable false alarms when the compiler diagnoses + programmer "mistakes". */ + +/* Do not warn if the entity is not used. */ +/* Applies to: + - function, variable, + - struct, union, struct/union member, + - enumeration, enumeration item, + - typedef, + in C++ also: class. */ +#define MAYBE_UNUSED _GL_ATTRIBUTE_MAYBE_UNUSED + +/* The contents of a character array is not meant to be NUL-terminated. */ +/* Applies to: struct/union members and variables that are arrays of element + type '[[un]signed] char'. */ +#define ATTRIBUTE_NONSTRING _GL_ATTRIBUTE_NONSTRING + +/* Do not warn if control flow falls through to the immediately + following 'case' or 'default' label. */ +/* Applies to: Empty statement (;), inside a 'switch' statement. */ +#define FALLTHROUGH _GL_ATTRIBUTE_FALLTHROUGH + + +/* ================== Attributes for debugging information ================== */ + +/* Attributes regarding debugging information emitted by the compiler. */ + +/* Omit the function from stack traces when debugging. */ +/* Applies to: function. */ +#define ATTRIBUTE_ARTIFICIAL _GL_ATTRIBUTE_ARTIFICIAL + +/* Make the entity visible to debuggers etc., even with '-fwhole-program'. */ +/* Applies to: functions, variables. */ +#define ATTRIBUTE_EXTERNALLY_VISIBLE _GL_ATTRIBUTE_EXTERNALLY_VISIBLE + + +/* ========== Attributes that mainly direct compiler optimizations ========== */ + +/* The function does not throw exceptions. */ +/* Applies to: functions. */ +#define ATTRIBUTE_NOTHROW _GL_ATTRIBUTE_NOTHROW + +/* Do not inline the function. */ +/* Applies to: functions. */ +#define ATTRIBUTE_NOINLINE _GL_ATTRIBUTE_NOINLINE + +/* Always inline the function, and report an error if the compiler + cannot inline. */ +/* Applies to: function. */ +#define ATTRIBUTE_ALWAYS_INLINE _GL_ATTRIBUTE_ALWAYS_INLINE + +/* It is OK for a compiler to omit duplicate calls with the same arguments. + This attribute is safe for a function that neither depends on + nor affects observable state, and always returns exactly once - + e.g., does not loop forever, and does not call longjmp. + (This attribute is stricter than ATTRIBUTE_PURE.) */ +/* Applies to: functions. */ +#define ATTRIBUTE_CONST _GL_ATTRIBUTE_CONST + +/* It is OK for a compiler to omit duplicate calls with the same + arguments if observable state is not changed between calls. + This attribute is safe for a function that does not affect + observable state, and always returns exactly once. + (This attribute is looser than ATTRIBUTE_CONST.) */ +/* Applies to: functions. */ +#define ATTRIBUTE_PURE _GL_ATTRIBUTE_PURE + +/* The function is rarely executed. */ +/* Applies to: functions. */ +#define ATTRIBUTE_COLD _GL_ATTRIBUTE_COLD + +/* If called from some other compilation unit, the function executes + code from that unit only by return or by exception handling, + letting the compiler optimize that unit more aggressively. */ +/* Applies to: functions. */ +#define ATTRIBUTE_LEAF _GL_ATTRIBUTE_LEAF + +/* For struct members: The member has the smallest possible alignment. + For struct, union, class: All members have the smallest possible alignment, + minimizing the memory required. */ +/* Applies to: struct members, struct, union, + in C++ also: class. */ +#define ATTRIBUTE_PACKED _GL_ATTRIBUTE_PACKED + + +/* ================ Attributes that make invalid code valid ================ */ + +/* Attributes that prevent fatal compiler optimizations for code that is not + fully ISO C compliant. */ + +/* Pointers to the type may point to the same storage as pointers to + other types, thus disabling strict aliasing optimization. */ +/* Applies to: types. */ +#define ATTRIBUTE_MAY_ALIAS _GL_ATTRIBUTE_MAY_ALIAS + + +#endif /* _GL_ATTRIBUTE_H */ |