util: New function popcount().

[openvswitch] / lib / util.h

diff --git a/lib/util.h b/lib/util.h
index 1bdaeee563ba5a9d0bf2b1275a5e6d63dbdb36e5..a8d86657325287b6c64b033491f4e6a8d0f5197b 100644 (file)
--- a/lib/util.h
+++ b/lib/util.h
@@ -17,6 +17,7 @@
 #ifndef UTIL_H
 #define UTIL_H 1
 
+#include <limits.h>
 #include <stdarg.h>
 #include <stdbool.h>
 #include <stddef.h>
@@ -61,7 +62,18 @@
 #define BUILD_ASSERT_DECL_GCCONLY(EXPR) ((void) 0)
 #endif
 
+/* Casts 'pointer' to 'type' and issues a compiler warning if the cast changes
+ * anything other than an outermost "const" or "volatile" qualifier.
+ *
+ * The cast to int is present only to suppress an "expression using sizeof
+ * bool" warning from "sparse" (see
+ * http://permalink.gmane.org/gmane.comp.parsers.sparse/2967). */
+#define CONST_CAST(TYPE, POINTER)                               \
+    ((void) sizeof ((int) ((POINTER) == (TYPE) (POINTER))),     \
+     (TYPE) (POINTER))
+
 extern const char *program_name;
+extern const char *subprogram_name;
 
 /* Returns the number of elements in ARRAY. */
 #define ARRAY_SIZE(ARRAY) (sizeof ARRAY / sizeof *ARRAY)
@@ -92,6 +104,14 @@ rightmost_1bit(uintmax_t x)
     return x & -x;
 }
 
+/* Returns 'x' with its rightmost 1-bit changed to a zero (e.g. 01011000 =>
+ * 01010000), or 0 if 'x' is 0. */
+static inline uintmax_t
+zero_rightmost_1bit(uintmax_t x)
+{
+    return x & (x - 1);
+}
+
 #ifndef MIN
 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
 #endif
@@ -187,6 +207,8 @@ void ovs_strzcpy(char *dst, const char *src, size_t size);
 
 void ovs_abort(int err_no, const char *format, ...)
     PRINTF_FORMAT(2, 3) NO_RETURN;
+void ovs_abort_valist(int err_no, const char *format, va_list)
+    PRINTF_FORMAT(2, 0) NO_RETURN;
 void ovs_fatal(int err_no, const char *format, ...)
     PRINTF_FORMAT(2, 3) NO_RETURN;
 void ovs_fatal_valist(int err_no, const char *format, va_list)
@@ -216,10 +238,14 @@ char *dir_name(const char *file_name);
 char *base_name(const char *file_name);
 char *abs_file_name(const char *dir, const char *file_name);
 
+char *xreadlink(const char *filename);
+char *follow_symlinks(const char *filename);
+
 void ignore(bool x OVS_UNUSED);
 int log_2_floor(uint32_t);
 int log_2_ceil(uint32_t);
 int ctz(uint32_t);
+int popcount(uint32_t);
 
 bool is_all_zeros(const uint8_t *, size_t);
 bool is_all_ones(const uint8_t *, size_t);