X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Fmacro.h;h=32cf714857809b5ec591cd484c9e1c0671654529;hp=79bee0396c3a52c4bed07f28f1878915bad8b282;hb=d442e2ec6e896c312bc616be7607332d978a45c9;hpb=919ce0b7affc6fbd68598b709faf477f56c22ac1

diff --git a/src/shared/macro.h b/src/shared/macro.h
index 79bee0396..32cf71485 100644
--- a/src/shared/macro.h
+++ b/src/shared/macro.h
@@ -46,6 +46,30 @@
 #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
 
@@ -78,7 +102,20 @@ 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))
+#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]))
 
@@ -117,6 +154,13 @@ static inline size_t ALIGN_TO(size_t l, size_t ali) {
                         _a < _b ? _a : _b;      \
                 })
 
+#define LESS_BY(A,B)                            \
+        __extension__ ({                        \
+                        typeof(A) _A = (A);     \
+                        typeof(B) _B = (B);     \
+                        _A > _B ? _A - _B : 0;  \
+                })
+
 #ifndef CLAMP
 #define CLAMP(x, low, high)                                             \
         __extension__ ({                                                \
@@ -147,9 +191,20 @@ static inline size_t ALIGN_TO(size_t l, size_t ali) {
         } while (false)
 
 #if defined(static_assert)
-#define assert_cc(expr) static_assert(expr, #expr)
+/* 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) struct UNIQUE(_assert_struct_) { char x[(expr) ? 0 : -1]; };
+#define assert_cc(expr)                                                 \
+        DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
+        struct UNIQUE(_assert_struct_) {                                \
+                char x[(expr) ? 0 : -1];                                \
+        };                                                              \
+        REENABLE_WARNING
 #endif
 
 #define assert_return(expr, r)                                          \
@@ -286,13 +341,14 @@ do {                                                                    \
 #define SET_FLAG(v, flag, b) \
         (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
 
-#define IN_SET(x, ...)                                                  \
+#define IN_SET(x, y, ...)                                               \
         ({                                                              \
-                const typeof(x) _x = (x);                               \
+                const typeof(y) _y = (y);                               \
+                const typeof(_y) _x = (x);                              \
                 unsigned _i;                                            \
                 bool _found = false;                                    \
-                for (_i = 0; _i < sizeof((const typeof(_x)[]) { __VA_ARGS__ })/sizeof(const typeof(_x)); _i++) \
-                        if (((const typeof(_x)[]) { __VA_ARGS__ })[_i] == _x) { \
+                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;                                  \
                         }                                               \