diff options
Diffstat (limited to 'shared/nm-utils/nm-macros-internal.h')
| -rw-r--r-- | shared/nm-utils/nm-macros-internal.h | 643 |
1 files changed, 643 insertions, 0 deletions
diff --git a/shared/nm-utils/nm-macros-internal.h b/shared/nm-utils/nm-macros-internal.h new file mode 100644 index 00000000..73075c68 --- /dev/null +++ b/shared/nm-utils/nm-macros-internal.h @@ -0,0 +1,643 @@ +/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */ +/* NetworkManager -- Network link manager + * + * This library 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 of the License, or (at your option) any later version. + * + * This library 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 library; if not, write to the + * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + * Boston, MA 02110-1301 USA. + * + * (C) Copyright 2014 Red Hat, Inc. + */ + +#ifndef __NM_MACROS_INTERNAL_H__ +#define __NM_MACROS_INTERNAL_H__ + +#include <stdlib.h> + +#include "nm-glib.h" + +/********************************************************/ + +#define _nm_packed __attribute__ ((packed)) +#define _nm_unused __attribute__ ((unused)) +#define _nm_pure __attribute__ ((pure)) +#define _nm_const __attribute__ ((const)) +#define _nm_printf(a,b) __attribute__ ((__format__ (__printf__, a, b))) + +#define nm_auto(fcn) __attribute__ ((cleanup(fcn))) + +/** + * nm_auto_free: + * + * Call free() on a variable location when it goes out of scope. + */ +#define nm_auto_free nm_auto(_nm_auto_free_impl) +GS_DEFINE_CLEANUP_FUNCTION(void*, _nm_auto_free_impl, free) + +static inline void +_nm_auto_unset_gvalue_impl (GValue *v) +{ + g_value_unset (v); +} +#define nm_auto_unset_gvalue nm_auto(_nm_auto_unset_gvalue_impl) + +static inline void +_nm_auto_free_gstring_impl (GString **str) +{ + if (*str) + g_string_free (*str, TRUE); +} +#define nm_auto_free_gstring nm_auto(_nm_auto_free_gstring_impl) + +/********************************************************/ + +/* http://stackoverflow.com/a/11172679 */ +#define _NM_UTILS_MACRO_FIRST(...) __NM_UTILS_MACRO_FIRST_HELPER(__VA_ARGS__, throwaway) +#define __NM_UTILS_MACRO_FIRST_HELPER(first, ...) first + +#define _NM_UTILS_MACRO_REST(...) __NM_UTILS_MACRO_REST_HELPER(__NM_UTILS_MACRO_REST_NUM(__VA_ARGS__), __VA_ARGS__) +#define __NM_UTILS_MACRO_REST_HELPER(qty, ...) __NM_UTILS_MACRO_REST_HELPER2(qty, __VA_ARGS__) +#define __NM_UTILS_MACRO_REST_HELPER2(qty, ...) __NM_UTILS_MACRO_REST_HELPER_##qty(__VA_ARGS__) +#define __NM_UTILS_MACRO_REST_HELPER_ONE(first) +#define __NM_UTILS_MACRO_REST_HELPER_TWOORMORE(first, ...) , __VA_ARGS__ +#define __NM_UTILS_MACRO_REST_NUM(...) \ + __NM_UTILS_MACRO_REST_SELECT_20TH(__VA_ARGS__, \ + TWOORMORE, TWOORMORE, TWOORMORE, TWOORMORE, TWOORMORE,\ + TWOORMORE, TWOORMORE, TWOORMORE, TWOORMORE, TWOORMORE,\ + TWOORMORE, TWOORMORE, TWOORMORE, TWOORMORE, TWOORMORE,\ + TWOORMORE, TWOORMORE, TWOORMORE, ONE, throwaway) +#define __NM_UTILS_MACRO_REST_SELECT_20TH(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20, ...) a20 + +/********************************************************/ + +/* http://stackoverflow.com/a/2124385/354393 */ + +#define NM_NARG(...) \ + _NM_NARG(__VA_ARGS__,_NM_NARG_RSEQ_N()) +#define _NM_NARG(...) \ + _NM_NARG_ARG_N(__VA_ARGS__) +#define _NM_NARG_ARG_N( \ + _1, _2, _3, _4, _5, _6, _7, _8, _9,_10, \ + _11,_12,_13,_14,_15,_16,_17,_18,_19,_20, \ + _21,_22,_23,_24,_25,_26,_27,_28,_29,_30, \ + _31,_32,_33,_34,_35,_36,_37,_38,_39,_40, \ + _41,_42,_43,_44,_45,_46,_47,_48,_49,_50, \ + _51,_52,_53,_54,_55,_56,_57,_58,_59,_60, \ + _61,_62,_63,N,...) N +#define _NM_NARG_RSEQ_N() \ + 63,62,61,60, \ + 59,58,57,56,55,54,53,52,51,50, \ + 49,48,47,46,45,44,43,42,41,40, \ + 39,38,37,36,35,34,33,32,31,30, \ + 29,28,27,26,25,24,23,22,21,20, \ + 19,18,17,16,15,14,13,12,11,10, \ + 9,8,7,6,5,4,3,2,1,0 + +/********************************************************/ + +#if defined (__GNUC__) +#define _NM_PRAGMA_WARNING_DO(warning) G_STRINGIFY(GCC diagnostic ignored warning) +#elif defined (__clang__) +#define _NM_PRAGMA_WARNING_DO(warning) G_STRINGIFY(clang diagnostic ignored warning) +#endif + +/* you can only suppress a specific warning that the compiler + * understands. Otherwise you will get another compiler warning + * about invalid pragma option. + * It's not that bad however, because gcc and clang often have the + * same name for the same warning. */ + +#if defined (__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)) +#define NM_PRAGMA_WARNING_DISABLE(warning) \ + _Pragma("GCC diagnostic push") \ + _Pragma(_NM_PRAGMA_WARNING_DO(warning)) +#elif defined (__clang__) +#define NM_PRAGMA_WARNING_DISABLE(warning) \ + _Pragma("clang diagnostic push") \ + _Pragma(_NM_PRAGMA_WARNING_DO(warning)) +#else +#define NM_PRAGMA_WARNING_DISABLE(warning) +#endif + +#if defined (__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)) +#define NM_PRAGMA_WARNING_REENABLE \ + _Pragma("GCC diagnostic pop") +#elif defined (__clang__) +#define NM_PRAGMA_WARNING_REENABLE \ + _Pragma("clang diagnostic pop") +#else +#define NM_PRAGMA_WARNING_REENABLE +#endif + +/********************************************************/ + +/** + * NM_G_ERROR_MSG: + * @error: (allow none): the #GError instance + * + * All functions must follow the convention that when they + * return a failure, they must also set the GError to a valid + * message. For external API however, we want to be extra + * careful before accessing the error instance. Use NM_G_ERROR_MSG() + * which is safe to use on NULL. + * + * Returns: the error message. + **/ +static inline const char * +NM_G_ERROR_MSG (GError *error) +{ + return error ? (error->message ? : "(null)") : "(no-error)"; \ +} + +/********************************************************/ + +/* macro to return strlen() of a compile time string. */ +#define NM_STRLEN(str) ( sizeof ("" str) - 1 ) + +#define NM_SET_OUT(out_val, value) \ + G_STMT_START { \ + typeof(*(out_val)) *_out_val = (out_val); \ + \ + if (_out_val) { \ + *_out_val = (value); \ + } \ + } G_STMT_END + +/********************************************************/ + +#define _NM_IN_SET_EVAL_1(op, _x, y1) \ + (_x == (y1)) + +#define _NM_IN_SET_EVAL_2(op, _x, y1, y2) \ + ( (_x == (y1)) \ + op (_x == (y2)) \ + ) + +#define _NM_IN_SET_EVAL_3(op, _x, y1, y2, y3) \ + ( (_x == (y1)) \ + op (_x == (y2)) \ + op (_x == (y3)) \ + ) + +#define _NM_IN_SET_EVAL_4(op, _x, y1, y2, y3, y4) \ + ( (_x == (y1)) \ + op (_x == (y2)) \ + op (_x == (y3)) \ + op (_x == (y4)) \ + ) + +#define _NM_IN_SET_EVAL_5(op, _x, y1, y2, y3, y4, y5) \ + ( (_x == (y1)) \ + op (_x == (y2)) \ + op (_x == (y3)) \ + op (_x == (y4)) \ + op (_x == (y5)) \ + ) + +#define _NM_IN_SET_EVAL_6(op, _x, y1, y2, y3, y4, y5, y6) \ + ( (_x == (y1)) \ + op (_x == (y2)) \ + op (_x == (y3)) \ + op (_x == (y4)) \ + op (_x == (y5)) \ + op (_x == (y6)) \ + ) + +#define _NM_IN_SET_EVAL_N2(op, _x, n, ...) _NM_IN_SET_EVAL_##n(op, _x, __VA_ARGS__) +#define _NM_IN_SET_EVAL_N(op, x, n, ...) \ + ({ \ + typeof(x) _x = (x); \ + !!_NM_IN_SET_EVAL_N2(op, _x, n, __VA_ARGS__); \ + }) + +/* Beware that this does short-circuit evaluation (use "||" instead of "|") + * which has a possibly unexpected non-function-like behavior. + * Use NM_IN_SET_SE if you need all arguments to be evaluted. */ +#define NM_IN_SET(x, ...) _NM_IN_SET_EVAL_N(||, x, NM_NARG (__VA_ARGS__), __VA_ARGS__) + +/* "SE" stands for "side-effect". Contrary to NM_IN_SET(), this does not do + * short-circuit evaluation, which can make a difference if the arguments have + * side-effects. */ +#define NM_IN_SET_SE(x, ...) _NM_IN_SET_EVAL_N(|, x, NM_NARG (__VA_ARGS__), __VA_ARGS__) + +/********************************************************/ + +static inline gboolean +_NM_IN_STRSET_streq (const char *x, const char *s) +{ + return s && strcmp (x, s) == 0; +} + +#define _NM_IN_STRSET_EVAL_1(op, _x, y1) \ + _NM_IN_STRSET_streq (_x, y1) + +#define _NM_IN_STRSET_EVAL_2(op, _x, y1, y2) \ + ( _NM_IN_STRSET_streq (_x, y1) \ + op _NM_IN_STRSET_streq (_x, y2) \ + ) + +#define _NM_IN_STRSET_EVAL_3(op, _x, y1, y2, y3) \ + ( _NM_IN_STRSET_streq (_x, y1) \ + op _NM_IN_STRSET_streq (_x, y2) \ + op _NM_IN_STRSET_streq (_x, y3) \ + ) + +#define _NM_IN_STRSET_EVAL_4(op, _x, y1, y2, y3, y4) \ + ( _NM_IN_STRSET_streq (_x, y1) \ + op _NM_IN_STRSET_streq (_x, y2) \ + op _NM_IN_STRSET_streq (_x, y3) \ + op _NM_IN_STRSET_streq (_x, y4) \ + ) + +#define _NM_IN_STRSET_EVAL_5(op, _x, y1, y2, y3, y4, y5) \ + ( _NM_IN_STRSET_streq (_x, y1) \ + op _NM_IN_STRSET_streq (_x, y2) \ + op _NM_IN_STRSET_streq (_x, y3) \ + op _NM_IN_STRSET_streq (_x, y4) \ + op _NM_IN_STRSET_streq (_x, y5) \ + ) + +#define _NM_IN_STRSET_EVAL_6(op, _x, y1, y2, y3, y4, y5, y6) \ + ( _NM_IN_STRSET_streq (_x, y1) \ + op _NM_IN_STRSET_streq (_x, y2) \ + op _NM_IN_STRSET_streq (_x, y3) \ + op _NM_IN_STRSET_streq (_x, y4) \ + op _NM_IN_STRSET_streq (_x, y5) \ + op _NM_IN_STRSET_streq (_x, y6) \ + ) + +#define _NM_IN_STRSET_EVAL_N2(op, _x, n, ...) _NM_IN_STRSET_EVAL_##n(op, _x, __VA_ARGS__) +#define _NM_IN_STRSET_EVAL_N(op, x, n, ...) \ + ({ \ + const char *_x = (x); \ + ( ((_x == NULL) && _NM_IN_SET_EVAL_N2 (op, (const char *) NULL, n, __VA_ARGS__)) \ + || ((_x != NULL) && _NM_IN_STRSET_EVAL_N2 (op, _x, n, __VA_ARGS__)) \ + ); \ + }) + +/* Beware that this does short-circuit evaluation (use "||" instead of "|") + * which has a possibly unexpected non-function-like behavior. + * Use NM_IN_STRSET_SE if you need all arguments to be evaluted. */ +#define NM_IN_STRSET(x, ...) _NM_IN_STRSET_EVAL_N(||, x, NM_NARG (__VA_ARGS__), __VA_ARGS__) + +/* "SE" stands for "side-effect". Contrary to NM_IN_STRSET(), this does not do + * short-circuit evaluation, which can make a difference if the arguments have + * side-effects. */ +#define NM_IN_STRSET_SE(x, ...) _NM_IN_STRSET_EVAL_N(|, x, NM_NARG (__VA_ARGS__), __VA_ARGS__) + +/*****************************************************************************/ + +#define nm_streq(s1, s2) (strcmp (s1, s2) == 0) +#define nm_streq0(s1, s2) (g_strcmp0 (s1, s2) == 0) + +/*****************************************************************************/ + +#define NM_PRINT_FMT_QUOTED(cond, prefix, str, suffix, str_else) \ + (cond) ? (prefix) : "", \ + (cond) ? (str) : (str_else), \ + (cond) ? (suffix) : "" +#define NM_PRINT_FMT_QUOTE_STRING(arg) NM_PRINT_FMT_QUOTED((arg), "\"", (arg), "\"", "(null)") + +/*****************************************************************************/ + +/* glib/C provides the following kind of assertions: + * - assert() -- disable with NDEBUG + * - g_return_if_fail() -- disable with G_DISABLE_CHECKS + * - g_assert() -- disable with G_DISABLE_ASSERT + * but they are all enabled by default and usually even production builds have + * these kind of assertions enabled. It also means, that disabling assertions + * is an untested configuration, and might have bugs. + * + * Add our own assertion macro nm_assert(), which is disabled by default and must + * be explicitly enabled. They are useful for more expensive checks or checks that + * depend less on runtime conditions (that is, are generally expected to be true). */ + +#ifndef NM_MORE_ASSERTS +#define NM_MORE_ASSERTS 0 +#endif + +#if NM_MORE_ASSERTS +#define nm_assert(cond) G_STMT_START { g_assert (cond); } G_STMT_END +#define nm_assert_not_reached() G_STMT_START { g_assert_not_reached (); } G_STMT_END +#else +#define nm_assert(cond) G_STMT_START { if (FALSE) { if (cond) { } } } G_STMT_END +#define nm_assert_not_reached() G_STMT_START { ; } G_STMT_END +#endif + +/*****************************************************************************/ + +#define NM_GOBJECT_PROPERTIES_DEFINE_BASE(...) \ +typedef enum { \ + _PROPERTY_ENUMS_0, \ + __VA_ARGS__ \ + _PROPERTY_ENUMS_LAST, \ +} _PropertyEnums; \ +static GParamSpec *obj_properties[_PROPERTY_ENUMS_LAST] = { NULL, } + +#define NM_GOBJECT_PROPERTIES_DEFINE(obj_type, ...) \ +NM_GOBJECT_PROPERTIES_DEFINE_BASE (__VA_ARGS__); \ +static inline void \ +_notify (obj_type *obj, _PropertyEnums prop) \ +{ \ + nm_assert (G_IS_OBJECT (obj)); \ + nm_assert ((gsize) prop < G_N_ELEMENTS (obj_properties)); \ + g_object_notify_by_pspec ((GObject *) obj, obj_properties[prop]); \ +} + +/*****************************************************************************/ + +static inline gpointer +nm_g_object_ref (gpointer obj) +{ + /* g_object_ref() doesn't accept NULL. */ + if (obj) + g_object_ref (obj); + return obj; +} + +static inline void +nm_g_object_unref (gpointer obj) +{ + /* g_object_unref() doesn't accept NULL. Usully, we workaround that + * by using g_clear_object(), but sometimes that is not convinient + * (for example as as destroy function for a hash table that can contain + * NULL values). */ + if (obj) + g_object_unref (obj); +} + +static inline gboolean +nm_clear_g_source (guint *id) +{ + if (id && *id) { + g_source_remove (*id); + *id = 0; + return TRUE; + } + return FALSE; +} + +static inline gboolean +nm_clear_g_signal_handler (gpointer self, gulong *id) +{ + if (id && *id) { + g_signal_handler_disconnect (self, *id); + *id = 0; + return TRUE; + } + return FALSE; +} + +static inline gboolean +nm_clear_g_variant (GVariant **variant) +{ + if (variant && *variant) { + g_variant_unref (*variant); + *variant = NULL; + return TRUE; + } + return FALSE; +} + +static inline gboolean +nm_clear_g_cancellable (GCancellable **cancellable) +{ + if (cancellable && *cancellable) { + g_cancellable_cancel (*cancellable); + g_object_unref (*cancellable); + *cancellable = NULL; + return TRUE; + } + return FALSE; +} + +/*****************************************************************************/ + +/* Determine whether @x is a power of two (@x being an integer type). + * For the special cases @x equals zero or one, it also returns true. + * For negative @x, always returns FALSE. That only applies, if the data + * type of @x is signed. */ +#define nm_utils_is_power_of_two(x) ({ \ + typeof(x) __x = (x); \ + \ + /* Check if the value is negative. In that case, return FALSE. + * The first expression is a compile time constant, depending on whether + * the type is signed. The second expression is a clumsy way for (__x >= 0), + * which causes a compiler warning for unsigned types. */ \ + ( ( ((typeof(__x)) -1) > ((typeof(__x)) 0) ) || (__x > 0) || (__x == 0) ) \ + && ((__x & (__x - 1)) == 0); \ + }) + +/*****************************************************************************/ + +/* check if @flags has exactly one flag (@check) set. You should call this + * only with @check being a compile time constant and a power of two. */ +#define NM_FLAGS_HAS(flags, check) \ + ( (G_STATIC_ASSERT_EXPR ( ((check) != 0) && ((check) & ((check)-1)) == 0 )), (NM_FLAGS_ANY ((flags), (check))) ) + +#define NM_FLAGS_ANY(flags, check) ( ( ((flags) & (check)) != 0 ) ? TRUE : FALSE ) +#define NM_FLAGS_ALL(flags, check) ( ( ((flags) & (check)) == (check) ) ? TRUE : FALSE ) + +#define NM_FLAGS_SET(flags, val) ({ \ + const typeof(flags) _flags = (flags); \ + const typeof(flags) _val = (val); \ + \ + _flags | _val; \ + }) + +#define NM_FLAGS_UNSET(flags, val) ({ \ + const typeof(flags) _flags = (flags); \ + const typeof(flags) _val = (val); \ + \ + _flags & (~_val); \ + }) + +#define NM_FLAGS_ASSIGN(flags, val, assign) ({ \ + const typeof(flags) _flags = (flags); \ + const typeof(flags) _val = (val); \ + \ + (assign) \ + ? _flags | (_val) \ + : _flags & (~_val); \ + }) + +/*****************************************************************************/ + +#define _NM_BACKPORT_SYMBOL_IMPL(VERSION, RETURN_TYPE, ORIG_FUNC, VERSIONED_FUNC, ARGS_TYPED, ARGS) \ +RETURN_TYPE VERSIONED_FUNC ARGS_TYPED; \ +RETURN_TYPE VERSIONED_FUNC ARGS_TYPED \ +{ \ + return ORIG_FUNC ARGS; \ +} \ +RETURN_TYPE ORIG_FUNC ARGS_TYPED; \ +__asm__(".symver "G_STRINGIFY(VERSIONED_FUNC)", "G_STRINGIFY(ORIG_FUNC)"@"G_STRINGIFY(VERSION)) + +#define NM_BACKPORT_SYMBOL(VERSION, RETURN_TYPE, FUNC, ARGS_TYPED, ARGS) \ +_NM_BACKPORT_SYMBOL_IMPL(VERSION, RETURN_TYPE, FUNC, _##FUNC##_##VERSION, ARGS_TYPED, ARGS) + +/*****************************************************************************/ + +static inline char * +nm_strstrip (char *str) +{ + /* g_strstrip doesn't like NULL. */ + return str ? g_strstrip (str) : NULL; +} + +/* g_ptr_array_sort()'s compare function takes pointers to the + * value. Thus, you cannot use strcmp directly. You can use + * nm_strcmp_p(). + * + * Like strcmp(), this function is not forgiving to accept %NULL. */ +static inline int +nm_strcmp_p (gconstpointer a, gconstpointer b) +{ + const char *s1 = *((const char **) a); + const char *s2 = *((const char **) b); + + return strcmp (s1, s2); +} + +/* like nm_strcmp_p(), suitable for g_ptr_array_sort_with_data(). + * g_ptr_array_sort() just casts nm_strcmp_p() to a function of different + * signature. I guess, in glib there are knowledgeable people that ensure + * that this additional argument doesn't cause problems due to different ABI + * for every architecture that glib supports. + * For NetworkManager, we'd rather avoid such stunts. + **/ +static inline int +nm_strcmp_p_with_data (gconstpointer a, gconstpointer b, gpointer user_data) +{ + const char *s1 = *((const char **) a); + const char *s2 = *((const char **) b); + + return strcmp (s1, s2); +} + +/*****************************************************************************/ + +static inline guint +nm_encode_version (guint major, guint minor, guint micro) { + /* analog to the preprocessor macro NM_ENCODE_VERSION(). */ + return (major << 16) | (minor << 8) | micro; +} + +static inline void +nm_decode_version (guint version, guint *major, guint *minor, guint *micro) { + *major = (version & 0xFFFF0000u) >> 16; + *minor = (version & 0x0000FF00u) >> 8; + *micro = (version & 0x000000FFu); +} +/*****************************************************************************/ + +/* if @str is NULL, return "(null)". Otherwise, allocate a buffer using + * alloca() of size @bufsize and fill it with @str. @str will be quoted with + * single quote, and in case @str is too long, the final quote will be '^'. */ +#define nm_strquote_a(bufsize, str) \ + ({ \ + G_STATIC_ASSERT ((bufsize) >= 6); \ + const gsize _BUFSIZE = (bufsize); \ + const char *const _s = (str); \ + char *_r; \ + gsize _l; \ + gboolean _truncated; \ + \ + nm_assert (_BUFSIZE >= 6); \ + \ + if (_s) { \ + _l = strlen (_s) + 3; \ + if ((_truncated = (_BUFSIZE < _l))) \ + _l = _BUFSIZE; \ + \ + _r = g_alloca (_l); \ + _r[0] = '\''; \ + memcpy (&_r[1], _s, _l - 3); \ + _r[_l - 2] = _truncated ? '^' : '\''; \ + _r[_l - 1] = '\0'; \ + } else \ + _r = "(null)"; \ + _r; \ + }) + +#define nm_sprintf_buf(buf, format, ...) ({ \ + char * _buf = (buf); \ + \ + /* some static assert trying to ensure that the buffer is statically allocated. + * It disallows a buffer size of sizeof(gpointer) to catch that. */ \ + G_STATIC_ASSERT (G_N_ELEMENTS (buf) == sizeof (buf) && sizeof (buf) != sizeof (char *)); \ + g_snprintf (_buf, sizeof (buf), \ + ""format"", ##__VA_ARGS__); \ + _buf; \ + }) + +#define nm_sprintf_bufa(n_elements, format, ...) \ + ({ \ + char *_buf; \ + \ + G_STATIC_ASSERT (sizeof (char[MAX ((n_elements), 1)]) == (n_elements)); \ + _buf = g_alloca (n_elements); \ + g_snprintf (_buf, n_elements, \ + ""format"", ##__VA_ARGS__); \ + _buf; \ + }) + +/*****************************************************************************/ + +/** + * The boolean type _Bool is C99 while we mostly stick to C89. However, _Bool is too + * convinient to miss and is effectively available in gcc and clang. So, just use it. + * + * Usually, one would include "stdbool.h" to get the "bool" define which aliases + * _Bool. We provide this define here, because we want to make use of it anywhere. + * (also, stdbool.h is again C99). + * + * Using _Bool has advantages over gboolean: + * + * - commonly _Bool is one byte large, instead of gboolean's 4 bytes (because gboolean + * is a typedef for gint). Especially when having boolean fields in a struct, we can + * thereby easily save some space. + * + * - _Bool type guarantees that two "true" expressions compare equal. E.g. the follwing + * will not work: + * gboolean v1 = 1; + * gboolean v2 = 2; + * g_assert_cmpint (v1, ==, v2); // will fail + * For that, we often to use !! to coerce gboolean values to 0 or 1: + * g_assert_cmpint (!!v2, ==, TRUE); + * With _Bool type, this will be handled properly by the compiler. + * + * - For structs, we might want to safe even more space and use bitfields: + * struct s1 { + * gboolean v1:1; + * }; + * But the problem here is that gboolean is signed, so that + * v1 will be either 0 or -1 (not 1, TRUE). Thus, the following + * fails: + * struct s1 s = { .v1 = TRUE, }; + * g_assert_cmpint (s1.v1, ==, TRUE); + * It will however work just fine with bool/_Bool while retaining the + * notion of having a boolean value. + * + * Also, add the defines for "true" and "false". Those are nicely highlighted by the editor + * as special types, contrary to glib's "TRUE"/"FALSE". + */ + +#ifndef bool +#define bool _Bool +#define true 1 +#define false 0 +#endif + +/*****************************************************************************/ + +#endif /* __NM_MACROS_INTERNAL_H__ */ |