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mirror of https://github.com/openvswitch/ovs synced 2025-08-28 21:07:47 +00:00
ovs/lib/util.h
Ben Pfaff fee0c96314 util: New function follow_symlinks().
It will acquire its first user in an upcoming commit.

Signed-off-by: Ben Pfaff <blp@nicira.com>
2012-08-01 10:55:57 -07:00

252 lines
8.5 KiB
C

/*
* Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef UTIL_H
#define UTIL_H 1
#include <stdarg.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "compiler.h"
#ifndef va_copy
#ifdef __va_copy
#define va_copy __va_copy
#else
#define va_copy(dst, src) ((dst) = (src))
#endif
#endif
#ifdef __CHECKER__
#define BUILD_ASSERT(EXPR) ((void) 0)
#define BUILD_ASSERT_DECL(EXPR) extern int (*build_assert(void))[1]
#elif !defined(__cplusplus)
/* Build-time assertion building block. */
#define BUILD_ASSERT__(EXPR) \
sizeof(struct { unsigned int build_assert_failed : (EXPR) ? 1 : -1; })
/* Build-time assertion for use in a statement context. */
#define BUILD_ASSERT(EXPR) (void) BUILD_ASSERT__(EXPR)
/* Build-time assertion for use in a declaration context. */
#define BUILD_ASSERT_DECL(EXPR) \
extern int (*build_assert(void))[BUILD_ASSERT__(EXPR)]
#else /* __cplusplus */
#include <boost/static_assert.hpp>
#define BUILD_ASSERT BOOST_STATIC_ASSERT
#define BUILD_ASSERT_DECL BOOST_STATIC_ASSERT
#endif /* __cplusplus */
#ifdef __GNUC__
#define BUILD_ASSERT_GCCONLY(EXPR) BUILD_ASSERT(EXPR)
#define BUILD_ASSERT_DECL_GCCONLY(EXPR) BUILD_ASSERT_DECL(EXPR)
#else
#define BUILD_ASSERT_GCCONLY(EXPR) ((void) 0)
#define BUILD_ASSERT_DECL_GCCONLY(EXPR) ((void) 0)
#endif
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)
/* Returns X / Y, rounding up. X must be nonnegative to round correctly. */
#define DIV_ROUND_UP(X, Y) (((X) + ((Y) - 1)) / (Y))
/* Returns X rounded up to the nearest multiple of Y. */
#define ROUND_UP(X, Y) (DIV_ROUND_UP(X, Y) * (Y))
/* Returns X rounded down to the nearest multiple of Y. */
#define ROUND_DOWN(X, Y) ((X) / (Y) * (Y))
/* Returns true if X is a power of 2, otherwise false. */
#define IS_POW2(X) ((X) && !((X) & ((X) - 1)))
static inline bool
is_pow2(uintmax_t x)
{
return IS_POW2(x);
}
/* Returns the rightmost 1-bit in 'x' (e.g. 01011000 => 00001000), or 0 if 'x'
* is 0. */
static inline uintmax_t
rightmost_1bit(uintmax_t x)
{
return x & -x;
}
#ifndef MIN
#define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
#endif
#ifndef MAX
#define MAX(X, Y) ((X) > (Y) ? (X) : (Y))
#endif
#define NOT_REACHED() abort()
/* Expands to a string that looks like "<file>:<line>", e.g. "tmp.c:10".
*
* See http://c-faq.com/ansi/stringize.html for an explanation of STRINGIZE and
* STRINGIZE2. */
#define SOURCE_LOCATOR __FILE__ ":" STRINGIZE(__LINE__)
#define STRINGIZE(ARG) STRINGIZE2(ARG)
#define STRINGIZE2(ARG) #ARG
/* Given a pointer-typed lvalue OBJECT, expands to a pointer type that may be
* assigned to OBJECT. */
#ifdef __GNUC__
#define OVS_TYPEOF(OBJECT) typeof(OBJECT)
#else
#define OVS_TYPEOF(OBJECT) void *
#endif
/* Given OBJECT of type pointer-to-structure, expands to the offset of MEMBER
* within an instance of the structure.
*
* The GCC-specific version avoids the technicality of undefined behavior if
* OBJECT is null, invalid, or not yet initialized. This makes some static
* checkers (like Coverity) happier. But the non-GCC version does not actually
* dereference any pointer, so it would be surprising for it to cause any
* problems in practice.
*/
#ifdef __GNUC__
#define OBJECT_OFFSETOF(OBJECT, MEMBER) offsetof(typeof(*(OBJECT)), MEMBER)
#else
#define OBJECT_OFFSETOF(OBJECT, MEMBER) \
((char *) &(OBJECT)->MEMBER - (char *) (OBJECT))
#endif
/* Given POINTER, the address of the given MEMBER in a STRUCT object, returns
the STRUCT object. */
#define CONTAINER_OF(POINTER, STRUCT, MEMBER) \
((STRUCT *) (void *) ((char *) (POINTER) - offsetof (STRUCT, MEMBER)))
/* Given POINTER, the address of the given MEMBER within an object of the type
* that that OBJECT points to, returns OBJECT as an assignment-compatible
* pointer type (either the correct pointer type or "void *"). OBJECT must be
* an lvalue.
*
* This is the same as CONTAINER_OF except that it infers the structure type
* from the type of '*OBJECT'. */
#define OBJECT_CONTAINING(POINTER, OBJECT, MEMBER) \
((OVS_TYPEOF(OBJECT)) (void *) \
((char *) (POINTER) - OBJECT_OFFSETOF(OBJECT, MEMBER)))
/* Given POINTER, the address of the given MEMBER within an object of the type
* that that OBJECT points to, assigns the address of the outer object to
* OBJECT, which must be an lvalue.
*
* Evaluates to 1. */
#define ASSIGN_CONTAINER(OBJECT, POINTER, MEMBER) \
((OBJECT) = OBJECT_CONTAINING(POINTER, OBJECT, MEMBER), 1)
#ifdef __cplusplus
extern "C" {
#endif
void set_program_name__(const char *name, const char *version,
const char *date, const char *time);
#define set_program_name(name) \
set_program_name__(name, VERSION, __DATE__, __TIME__)
const char *get_program_version(void);
void ovs_print_version(uint8_t min_ofp, uint8_t max_ofp);
void out_of_memory(void) NO_RETURN;
void *xmalloc(size_t) MALLOC_LIKE;
void *xcalloc(size_t, size_t) MALLOC_LIKE;
void *xzalloc(size_t) MALLOC_LIKE;
void *xrealloc(void *, size_t);
void *xmemdup(const void *, size_t) MALLOC_LIKE;
char *xmemdup0(const char *, size_t) MALLOC_LIKE;
char *xstrdup(const char *) MALLOC_LIKE;
char *xasprintf(const char *format, ...) PRINTF_FORMAT(1, 2) MALLOC_LIKE;
char *xvasprintf(const char *format, va_list) PRINTF_FORMAT(1, 0) MALLOC_LIKE;
void *x2nrealloc(void *p, size_t *n, size_t s);
void ovs_strlcpy(char *dst, const char *src, size_t size);
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)
PRINTF_FORMAT(2, 0) NO_RETURN;
void ovs_error(int err_no, const char *format, ...) PRINTF_FORMAT(2, 3);
void ovs_error_valist(int err_no, const char *format, va_list)
PRINTF_FORMAT(2, 0);
const char *ovs_retval_to_string(int);
void ovs_hex_dump(FILE *, const void *, size_t, uintptr_t offset, bool ascii);
bool str_to_int(const char *, int base, int *);
bool str_to_long(const char *, int base, long *);
bool str_to_llong(const char *, int base, long long *);
bool str_to_uint(const char *, int base, unsigned int *);
bool str_to_ulong(const char *, int base, unsigned long *);
bool str_to_ullong(const char *, int base, unsigned long long *);
bool str_to_double(const char *, double *);
int hexit_value(int c);
unsigned int hexits_value(const char *s, size_t n, bool *ok);
const char *english_list_delimiter(size_t index, size_t total);
char *get_cwd(void);
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);
bool is_all_zeros(const uint8_t *, size_t);
bool is_all_ones(const uint8_t *, size_t);
void bitwise_copy(const void *src, unsigned int src_len, unsigned int src_ofs,
void *dst, unsigned int dst_len, unsigned int dst_ofs,
unsigned int n_bits);
void bitwise_zero(void *dst_, unsigned int dst_len, unsigned dst_ofs,
unsigned int n_bits);
void bitwise_one(void *dst_, unsigned int dst_len, unsigned dst_ofs,
unsigned int n_bits);
bool bitwise_is_all_zeros(const void *, unsigned int len, unsigned int ofs,
unsigned int n_bits);
void bitwise_put(uint64_t value,
void *dst, unsigned int dst_len, unsigned int dst_ofs,
unsigned int n_bits);
uint64_t bitwise_get(const void *src, unsigned int src_len,
unsigned int src_ofs, unsigned int n_bits);
#ifdef __cplusplus
}
#endif
#endif /* util.h */