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[libgit2.git] / src / common.h

/*
 * Copyright (C) the libgit2 contributors. All rights reserved.
 *
 * This file is part of libgit2, distributed under the GNU GPL v2 with
 * a Linking Exception. For full terms see the included COPYING file.
 */
#ifndef INCLUDE_common_h__
#define INCLUDE_common_h__

#ifndef LIBGIT2_NO_FEATURES_H
# include "git2/sys/features.h"
#endif

#include "git2/common.h"
#include "cc-compat.h"

/** Declare a function as always inlined. */
#if defined(_MSC_VER)
# define GIT_INLINE(type) static __inline type
#elif defined(__GNUC__)
# define GIT_INLINE(type) static __inline__ type
#elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
# define GIT_INLINE(type) static inline type
#else
# define GIT_INLINE(type) static type
#endif

/** Support for gcc/clang __has_builtin intrinsic */
#ifndef __has_builtin
# define __has_builtin(x) 0
#endif

/**
 * Declare that a function's return value must be used.
 *
 * Used mostly to guard against potential silent bugs at runtime. This is
 * recommended to be added to functions that:
 *
 * - Allocate / reallocate memory. This prevents memory leaks or errors where
 *   buffers are expected to have grown to a certain size, but could not be
 *   resized.
 * - Acquire locks. When a lock cannot be acquired, that will almost certainly
 *   cause a data race / undefined behavior.
 */
#if defined(__GNUC__)
# define GIT_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
#else
# define GIT_WARN_UNUSED_RESULT
#endif

#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <sys/types.h>
#include <sys/stat.h>

#ifdef GIT_WIN32

# include <io.h>
# include <direct.h>
# include <winsock2.h>
# include <windows.h>
# include <ws2tcpip.h>
# include "win32/msvc-compat.h"
# include "win32/mingw-compat.h"
# include "win32/w32_common.h"
# include "win32/win32-compat.h"
# include "win32/error.h"
# include "win32/version.h"
# ifdef GIT_THREADS
#	include "win32/thread.h"
# endif

#else

# include <unistd.h>
# include <strings.h>
# ifdef GIT_THREADS
#	include <pthread.h>
#	include <sched.h>
# endif

#define GIT_LIBGIT2_CALL
#define GIT_SYSTEM_CALL

#ifdef GIT_USE_STAT_ATIMESPEC
# define st_atim st_atimespec
# define st_ctim st_ctimespec
# define st_mtim st_mtimespec
#endif

# include <arpa/inet.h>

#endif

#include "git2/types.h"
#include "git2/errors.h"
#include "errors.h"
#include "thread.h"
#include "integer.h"
#include "assert_safe.h"
#include "utf8.h"

/*
 * Include the declarations for deprecated functions; this ensures
 * that they're decorated with the proper extern/visibility attributes.
 */
#include "git2/deprecated.h"

#include "posix.h"

#define DEFAULT_BUFSIZE 65536
#define FILEIO_BUFSIZE DEFAULT_BUFSIZE
#define FILTERIO_BUFSIZE DEFAULT_BUFSIZE
#define NETIO_BUFSIZE DEFAULT_BUFSIZE

/**
 * Check a pointer allocation result, returning -1 if it failed.
 */
#define GIT_ERROR_CHECK_ALLOC(ptr) if (ptr == NULL) { return -1; }

/**
 * Check a buffer allocation result, returning -1 if it failed.
 */
#define GIT_ERROR_CHECK_ALLOC_BUF(buf) if ((void *)(buf) == NULL || git_buf_oom(buf)) { return -1; }

/**
 * Check a return value and propagate result if non-zero.
 */
#define GIT_ERROR_CHECK_ERROR(code) \
	do { int _err = (code); if (_err) return _err; } while (0)

/**
 * Check a versioned structure for validity
 */
GIT_INLINE(int) git_error__check_version(const void *structure, unsigned int expected_max, const char *name)
{
	unsigned int actual;

	if (!structure)
		return 0;

	actual = *(const unsigned int*)structure;
	if (actual > 0 && actual <= expected_max)
		return 0;

	git_error_set(GIT_ERROR_INVALID, "invalid version %d on %s", actual, name);
	return -1;
}
#define GIT_ERROR_CHECK_VERSION(S,V,N) if (git_error__check_version(S,V,N) < 0) return -1

/**
 * Initialize a structure with a version.
 */
GIT_INLINE(void) git__init_structure(void *structure, size_t len, unsigned int version)
{
	memset(structure, 0, len);
	*((int*)structure) = version;
}
#define GIT_INIT_STRUCTURE(S,V) git__init_structure(S, sizeof(*S), V)

#define GIT_INIT_STRUCTURE_FROM_TEMPLATE(PTR,VERSION,TYPE,TPL) do { \
	TYPE _tmpl = TPL; \
	GIT_ERROR_CHECK_VERSION(&(VERSION), _tmpl.version, #TYPE);	\
	memcpy((PTR), &_tmpl, sizeof(_tmpl)); } while (0)


/** Check for additive overflow, setting an error if would occur. */
#define GIT_ADD_SIZET_OVERFLOW(out, one, two) \
	(git__add_sizet_overflow(out, one, two) ? (git_error_set_oom(), 1) : 0)

/** Check for additive overflow, setting an error if would occur. */
#define GIT_MULTIPLY_SIZET_OVERFLOW(out, nelem, elsize) \
	(git__multiply_sizet_overflow(out, nelem, elsize) ? (git_error_set_oom(), 1) : 0)

/** Check for additive overflow, failing if it would occur. */
#define GIT_ERROR_CHECK_ALLOC_ADD(out, one, two) \
	if (GIT_ADD_SIZET_OVERFLOW(out, one, two)) { return -1; }

#define GIT_ERROR_CHECK_ALLOC_ADD3(out, one, two, three) \
	if (GIT_ADD_SIZET_OVERFLOW(out, one, two) || \
		GIT_ADD_SIZET_OVERFLOW(out, *(out), three)) { return -1; }

#define GIT_ERROR_CHECK_ALLOC_ADD4(out, one, two, three, four) \
	if (GIT_ADD_SIZET_OVERFLOW(out, one, two) || \
		GIT_ADD_SIZET_OVERFLOW(out, *(out), three) || \
		GIT_ADD_SIZET_OVERFLOW(out, *(out), four)) { return -1; }

#define GIT_ERROR_CHECK_ALLOC_ADD5(out, one, two, three, four, five) \
	if (GIT_ADD_SIZET_OVERFLOW(out, one, two) || \
		GIT_ADD_SIZET_OVERFLOW(out, *(out), three) || \
		GIT_ADD_SIZET_OVERFLOW(out, *(out), four) || \
		GIT_ADD_SIZET_OVERFLOW(out, *(out), five)) { return -1; }

/** Check for multiplicative overflow, failing if it would occur. */
#define GIT_ERROR_CHECK_ALLOC_MULTIPLY(out, nelem, elsize) \
	if (GIT_MULTIPLY_SIZET_OVERFLOW(out, nelem, elsize)) { return -1; }

/* NOTE: other git_error functions are in the public errors.h header file */

#include "util.h"

#endif