chiark / gitweb /
build-sys: fix build on compilers without static_assert
[elogind.git] / src / shared / macro.h
index 29d91392f8abc3848a3f454307ea9560f36a3a73..ae2971fad141f54959bc89d0e50675f5faa2497a 100644 (file)
@@ -27,9 +27,9 @@
 #include <sys/uio.h>
 #include <inttypes.h>
 
-#define _printf_attr_(a,b) __attribute__ ((format (printf, a, b)))
+#define _printf_(a,b) __attribute__ ((format (printf, a, b)))
+#define _alloc_(...) __attribute__ ((alloc_size(__VA_ARGS__)))
 #define _sentinel_ __attribute__ ((sentinel))
-#define _noreturn_ __attribute__((noreturn))
 #define _unused_ __attribute__ ((unused))
 #define _destructor_ __attribute__ ((destructor))
 #define _pure_ __attribute__ ((pure))
 #define _public_ __attribute__ ((visibility("default")))
 #define _hidden_ __attribute__ ((visibility("hidden")))
 #define _weakref_(x) __attribute__((weakref(#x)))
-#define _introspect_(x) __attribute__((section("introspect." x)))
 #define _alignas_(x) __attribute__((aligned(__alignof(x))))
+#define _cleanup_(x) __attribute__((cleanup(x)))
+
+/* Temporarily disable some warnings */
+#define DISABLE_WARNING_DECLARATION_AFTER_STATEMENT                     \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wdeclaration-after-statement\"")
+
+#define DISABLE_WARNING_FORMAT_NONLITERAL                               \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
+
+#define DISABLE_WARNING_MISSING_PROTOTYPES                              \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wmissing-prototypes\"")
+
+#define DISABLE_WARNING_NONNULL                                         \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wnonnull\"")
+
+#define DISABLE_WARNING_SHADOW                                          \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wshadow\"")
+
+#define REENABLE_WARNING                                                \
+        _Pragma("GCC diagnostic pop")
+
+/* automake test harness */
+#define EXIT_TEST_SKIP 77
 
 #define XSTRINGIFY(x) #x
 #define STRINGIFY(x) XSTRINGIFY(x)
 
+#define XCONCATENATE(x, y) x ## y
+#define CONCATENATE(x, y) XCONCATENATE(x, y)
+
+#define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
+#define UNIQ __COUNTER__
+
 /* Rounds up */
-#define ALIGN(l) ALIGN_TO((l), sizeof(void*))
+
+#define ALIGN4(l) (((l) + 3) & ~3)
+#define ALIGN8(l) (((l) + 7) & ~7)
+
+#if __SIZEOF_POINTER__ == 8
+#define ALIGN(l) ALIGN8(l)
+#elif __SIZEOF_POINTER__ == 4
+#define ALIGN(l) ALIGN4(l)
+#else
+#error "Wut? Pointers are neither 4 nor 8 bytes long?"
+#endif
+
+#define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) (p)))
+#define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) (p)))
+#define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) (p)))
+
 static inline size_t ALIGN_TO(size_t l, size_t ali) {
         return ((l + ali - 1) & ~(ali - 1));
 }
 
+#define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) (p), (ali)))
+
+/* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */
+static inline unsigned long ALIGN_POWER2(unsigned long u) {
+        /* clz(0) is undefined */
+        if (u == 1)
+                return 1;
+
+        /* left-shift overflow is undefined */
+        if (__builtin_clzl(u - 1UL) < 1)
+                return 0;
+
+        return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL));
+}
+
 #define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
 
 /*
@@ -62,43 +125,88 @@ static inline size_t ALIGN_TO(size_t l, size_t ali) {
  * @ptr: the pointer to the member.
  * @type: the type of the container struct this is embedded in.
  * @member: the name of the member within the struct.
- *
  */
-#define container_of(ptr, type, member) ({ \
-        const typeof( ((type *)0)->member ) *__mptr = (ptr); \
-        (type *)( (char *)__mptr - offsetof(type,member) );})
-
-#ifndef MAX
-#define MAX(a,b)                                \
-        __extension__ ({                        \
-                        typeof(a) _a = (a);     \
-                        typeof(b) _b = (b);     \
-                        _a > _b ? _a : _b;      \
+#define container_of(ptr, type, member) __container_of(UNIQ, (ptr), type, member)
+#define __container_of(uniq, ptr, type, member)                         \
+        __extension__ ({                                                \
+                const typeof( ((type*)0)->member ) *UNIQ_T(A, uniq) = (ptr); \
+                (type*)( (char *)UNIQ_T(A, uniq) - offsetof(type,member) ); \
+        })
+
+#undef MAX
+#define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
+#define __MAX(aq, a, bq, b)                             \
+        __extension__ ({                                \
+                const typeof(a) UNIQ_T(A, aq) = (a);    \
+                const typeof(b) UNIQ_T(B, bq) = (b);    \
+                UNIQ_T(A,aq) > UNIQ_T(B,bq) ? UNIQ_T(A,aq) : UNIQ_T(B,bq); \
+        })
+
+/* evaluates to (void) if _A or _B are not constant or of different types */
+#define CONST_MAX(_A, _B) \
+        __extension__ (__builtin_choose_expr(                           \
+                __builtin_constant_p(_A) &&                             \
+                __builtin_constant_p(_B) &&                             \
+                __builtin_types_compatible_p(typeof(_A), typeof(_B)),   \
+                ((_A) > (_B)) ? (_A) : (_B),                            \
+                (void)0))
+
+/* takes two types and returns the size of the larger one */
+#define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
+
+#define MAX3(x,y,z)                                     \
+        __extension__ ({                                \
+                        const typeof(x) _c = MAX(x,y);  \
+                        MAX(_c, z);                     \
                 })
-#endif
-
-#define MAX3(a,b,c)                             \
-        MAX(MAX(a,b),c)
 
-#ifndef MIN
-#define MIN(a,b)                                \
-        __extension__ ({                        \
-                        typeof(a) _a = (a);     \
-                        typeof(b) _b = (b);     \
-                        _a < _b ? _a : _b;      \
+#undef MIN
+#define MIN(a, b) __MIN(UNIQ, (a), UNIQ, (b))
+#define __MIN(aq, a, bq, b)                             \
+        __extension__ ({                                \
+                const typeof(a) UNIQ_T(A, aq) = (a);    \
+                const typeof(b) UNIQ_T(B, bq) = (b);    \
+                UNIQ_T(A,aq) < UNIQ_T(B,bq) ? UNIQ_T(A,aq) : UNIQ_T(B,bq); \
+        })
+
+#define MIN3(x,y,z)                                     \
+        __extension__ ({                                \
+                        const typeof(x) _c = MIN(x,y);  \
+                        MIN(_c, z);                     \
                 })
-#endif
-
-#define MIN3(a,b,c)                             \
-        MIN(MIN(a,b),c)
 
-#define CLAMP(x, low, high)                                             \
+#define LESS_BY(a, b) __LESS_BY(UNIQ, (a), UNIQ, (b))
+#define __LESS_BY(aq, a, bq, b)                         \
+        __extension__ ({                                \
+                const typeof(a) UNIQ_T(A, aq) = (a);    \
+                const typeof(b) UNIQ_T(B, bq) = (b);    \
+                UNIQ_T(A,aq) > UNIQ_T(B,bq) ? UNIQ_T(A,aq) - UNIQ_T(B,bq) : 0; \
+        })
+
+#undef CLAMP
+#define CLAMP(x, low, high) __CLAMP(UNIQ, (x), UNIQ, (low), UNIQ, (high))
+#define __CLAMP(xq, x, lowq, low, highq, high)                          \
         __extension__ ({                                                \
-                        typeof(x) _x = (x);                             \
-                        typeof(low) _low = (low);                       \
-                        typeof(high) _high = (high);                    \
-                        ((_x > _high) ? _high : ((_x < _low) ? _low : _x)); \
-                })
+                const typeof(x) UNIQ_T(X,xq) = (x);                     \
+                const typeof(low) UNIQ_T(LOW,lowq) = (low);             \
+                const typeof(high) UNIQ_T(HIGH,highq) = (high);         \
+                        UNIQ_T(X,xq) > UNIQ_T(HIGH,highq) ?             \
+                                UNIQ_T(HIGH,highq) :                    \
+                                UNIQ_T(X,xq) < UNIQ_T(LOW,lowq) ?       \
+                                        UNIQ_T(LOW,lowq) :              \
+                                        UNIQ_T(X,xq);                   \
+        })
+
+/* [(x + y - 1) / y] suffers from an integer overflow, even though the
+ * computation should be possible in the given type. Therefore, we use
+ * [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
+ * quotient and the remainder, so both should be equally fast. */
+#define DIV_ROUND_UP(_x, _y)                                            \
+        __extension__ ({                                                \
+                const typeof(_x) __x = (_x);                            \
+                const typeof(_y) __y = (_y);                            \
+                (__x / __y + !!(__x % __y));                            \
+        })
 
 #define assert_se(expr)                                                 \
         do {                                                            \
@@ -120,42 +228,66 @@ static inline size_t ALIGN_TO(size_t l, size_t ali) {
         } while (false)
 
 #if defined(static_assert)
-#define assert_cc(expr)                         \
-        do {                                    \
-                static_assert(expr, #expr);     \
-        } while (false)
+/* static_assert() is sometimes defined in a way that trips up
+ * -Wdeclaration-after-statement, hence let's temporarily turn off
+ * this warning around it. */
+#define assert_cc(expr)                                                 \
+        DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
+        static_assert(expr, #expr);                                     \
+        REENABLE_WARNING
 #else
-#define assert_cc(expr)                         \
-        do {                                    \
-                switch (0) {                    \
-                case 0:                         \
-                case !!(expr):                  \
-                        ;                       \
-                }                               \
-        } while (false)
+#define assert_cc(expr)                                                 \
+        DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
+        struct CONCATENATE(_assert_struct_, __COUNTER__) {              \
+                char x[(expr) ? 0 : -1];                                \
+        };                                                              \
+        REENABLE_WARNING
 #endif
 
+#define assert_return(expr, r)                                          \
+        do {                                                            \
+                if (_unlikely_(!(expr))) {                              \
+                        log_assert_failed_return(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
+                        return (r);                                     \
+                }                                                       \
+        } while (false)
+
+#define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
+#define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
 #define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
-#define UINT_TO_PTR(u) ((void*) ((uintptr_t) (u)))
+#define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 
+#define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
+#define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
+#define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
+#define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
+
+#define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
+#define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
 #define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
-#define UINT32_TO_PTR(u) ((void*) ((uintptr_t) (u)))
+#define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 
-#define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
-#define ULONG_TO_PTR(u) ((void*) ((uintptr_t) (u)))
+#define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
+#define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
+#define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
+#define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 
-#define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
-#define INT_TO_PTR(u) ((void*) ((intptr_t) (u)))
+#define PTR_TO_SIZE(p) ((size_t) ((uintptr_t) (p)))
+#define SIZE_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 
-#define TO_INT32(p) ((int32_t) ((intptr_t) (p)))
-#define INT32_TO_PTR(u) ((void*) ((intptr_t) (u)))
+/* The following macros add 1 when converting things, since UID 0 is a
+ * valid UID, while the pointer NULL is special */
+#define PTR_TO_UID(p) ((uid_t) (((uintptr_t) (p))-1))
+#define UID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
 
-#define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
-#define LONG_TO_PTR(u) ((void*) ((intptr_t) (u)))
+#define PTR_TO_GID(p) ((gid_t) (((uintptr_t) (p))-1))
+#define GID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
 
 #define memzero(x,l) (memset((x), 0, (l)))
 #define zero(x) (memzero(&(x), sizeof(x)))
 
+#define CHAR_TO_STR(x) ((char[2]) { x, 0 })
+
 #define char_array_0(x) x[sizeof(x)-1] = 0;
 
 #define IOVEC_SET_STRING(i, s)                  \
@@ -194,14 +326,6 @@ static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
         return k;
 }
 
-#define _cleanup_free_ __attribute__((cleanup(freep)))
-#define _cleanup_fclose_ __attribute__((cleanup(fclosep)))
-#define _cleanup_close_ __attribute__((cleanup(closep)))
-#define _cleanup_closedir_ __attribute__((cleanup(closedirp)))
-#define _cleanup_umask_ __attribute__((cleanup(umaskp)))
-#define _cleanup_set_free_ __attribute__((cleanup(set_freep)))
-#define _cleanup_strv_free_ __attribute__((cleanup(strv_freep)))
-
 #define VA_FORMAT_ADVANCE(format, ap)                                   \
 do {                                                                    \
         int _argtypes[128];                                             \
@@ -247,4 +371,86 @@ do {                                                                    \
         }                                                               \
 } while(false)
 
+ /* Because statfs.t_type can be int on some architectures, we have to cast
+  * the const magic to the type, otherwise the compiler warns about
+  * signed/unsigned comparison, because the magic can be 32 bit unsigned.
+ */
+#define F_TYPE_EQUAL(a, b) (a == (typeof(a)) b)
+
+/* Returns the number of chars needed to format variables of the
+ * specified type as a decimal string. Adds in extra space for a
+ * negative '-' prefix. */
+#define DECIMAL_STR_MAX(type)                                           \
+        (2+(sizeof(type) <= 1 ? 3 :                                     \
+            sizeof(type) <= 2 ? 5 :                                     \
+            sizeof(type) <= 4 ? 10 :                                    \
+            sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
+
+#define SET_FLAG(v, flag, b) \
+        (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
+
+#define IN_SET(x, y, ...)                                               \
+        ({                                                              \
+                const typeof(y) _y = (y);                               \
+                const typeof(_y) _x = (x);                              \
+                unsigned _i;                                            \
+                bool _found = false;                                    \
+                for (_i = 0; _i < 1 + sizeof((const typeof(_x)[]) { __VA_ARGS__ })/sizeof(const typeof(_x)); _i++) \
+                        if (((const typeof(_x)[]) { _y, __VA_ARGS__ })[_i] == _x) { \
+                                _found = true;                          \
+                                break;                                  \
+                        }                                               \
+                _found;                                                 \
+        })
+
+/* Return a nulstr for a standard cascade of configuration directories,
+ * suitable to pass to conf_files_list_nulstr or config_parse_many. */
+#define CONF_DIRS_NULSTR(n) \
+        "/etc/" n ".d\0" \
+        "/run/" n ".d\0" \
+        "/usr/local/lib/" n ".d\0" \
+        "/usr/lib/" n ".d\0" \
+        CONF_DIR_SPLIT_USR(n)
+
+#ifdef HAVE_SPLIT_USR
+#define CONF_DIR_SPLIT_USR(n) "/lib/" n ".d\0"
+#else
+#define CONF_DIR_SPLIT_USR(n)
+#endif
+
+/* Define C11 thread_local attribute even on older gcc compiler
+ * version */
+#ifndef thread_local
+/*
+ * Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
+ * see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
+ */
+#if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
+#define thread_local _Thread_local
+#else
+#define thread_local __thread
+#endif
+#endif
+
+/* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
+ * compiler versions */
+#ifndef noreturn
+#if __STDC_VERSION__ >= 201112L
+#define noreturn _Noreturn
+#else
+#define noreturn __attribute__((noreturn))
+#endif
+#endif
+
+#define UID_INVALID ((uid_t) -1)
+#define GID_INVALID ((gid_t) -1)
+#define MODE_INVALID ((mode_t) -1)
+
+#define DEFINE_TRIVIAL_CLEANUP_FUNC(type, func)                 \
+        static inline void func##p(type *p) {                   \
+                if (*p)                                         \
+                        func(*p);                               \
+        }                                                       \
+        struct __useless_struct_to_allow_trailing_semicolon__
+
 #include "log.h"