git-compat-util: move wrapper.c funcs to its header

Since the functions in wrapper.c are widely used across the codebase,
include it by default in git-compat-util.h. A future patch will remove
now unnecessary inclusions of wrapper.h from other files.

Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

wrapper.h

@@ -1,6 +1,42 @@
 #ifndef WRAPPER_H
 #define WRAPPER_H
 
+char *xstrdup(const char *str);
+void *xmalloc(size_t size);
+void *xmallocz(size_t size);
+void *xmallocz_gently(size_t size);
+void *xmemdupz(const void *data, size_t len);
+char *xstrndup(const char *str, size_t len);
+void *xrealloc(void *ptr, size_t size);
+void *xcalloc(size_t nmemb, size_t size);
+void xsetenv(const char *name, const char *value, int overwrite);
+void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
+const char *mmap_os_err(void);
+void *xmmap_gently(void *start, size_t length, int prot, int flags, int fd, off_t offset);
+int xopen(const char *path, int flags, ...);
+ssize_t xread(int fd, void *buf, size_t len);
+ssize_t xwrite(int fd, const void *buf, size_t len);
+ssize_t xpread(int fd, void *buf, size_t len, off_t offset);
+int xdup(int fd);
+FILE *xfopen(const char *path, const char *mode);
+FILE *xfdopen(int fd, const char *mode);
+int xmkstemp(char *temp_filename);
+int xmkstemp_mode(char *temp_filename, int mode);
+char *xgetcwd(void);
+FILE *fopen_for_writing(const char *path);
+FILE *fopen_or_warn(const char *path, const char *mode);
+
+/*
+ * Like strncmp, but only return zero if s is NUL-terminated and exactly len
+ * characters long.  If it is not, consider it greater than t.
+ */
+int xstrncmpz(const char *s, const char *t, size_t len);
+
+__attribute__((format (printf, 3, 4)))
+int xsnprintf(char *dst, size_t max, const char *fmt, ...);
+
+int xgethostname(char *buf, size_t len);
+
 /* set default permissions by passing mode arguments to open(2) */
 int git_mkstemps_mode(char *pattern, int suffix_len, int mode);
 int git_mkstemp_mode(char *pattern, int mode);
@@ -33,4 +69,79 @@ void write_file(const char *path, const char *fmt, ...);
 /* Return 1 if the file is empty or does not exists, 0 otherwise. */
 int is_empty_or_missing_file(const char *filename);
 
+enum fsync_action {
+	FSYNC_WRITEOUT_ONLY,
+	FSYNC_HARDWARE_FLUSH
+};
+
+/*
+ * Issues an fsync against the specified file according to the specified mode.
+ *
+ * FSYNC_WRITEOUT_ONLY attempts to use interfaces available on some operating
+ * systems to flush the OS cache without issuing a flush command to the storage
+ * controller. If those interfaces are unavailable, the function fails with
+ * ENOSYS.
+ *
+ * FSYNC_HARDWARE_FLUSH does an OS writeout and hardware flush to ensure that
+ * changes are durable. It is not expected to fail.
+ */
+int git_fsync(int fd, enum fsync_action action);
+
+/*
+ * Writes out trace statistics for fsync using the trace2 API.
+ */
+void trace_git_fsync_stats(void);
+
+/*
+ * Preserves errno, prints a message, but gives no warning for ENOENT.
+ * Returns 0 on success, which includes trying to unlink an object that does
+ * not exist.
+ */
+int unlink_or_warn(const char *path);
+ /*
+  * Tries to unlink file.  Returns 0 if unlink succeeded
+  * or the file already didn't exist.  Returns -1 and
+  * appends a message to err suitable for
+  * 'error("%s", err->buf)' on error.
+  */
+int unlink_or_msg(const char *file, struct strbuf *err);
+/*
+ * Preserves errno, prints a message, but gives no warning for ENOENT.
+ * Returns 0 on success, which includes trying to remove a directory that does
+ * not exist.
+ */
+int rmdir_or_warn(const char *path);
+/*
+ * Calls the correct function out of {unlink,rmdir}_or_warn based on
+ * the supplied file mode.
+ */
+int remove_or_warn(unsigned int mode, const char *path);
+
+/*
+ * Call access(2), but warn for any error except "missing file"
+ * (ENOENT or ENOTDIR).
+ */
+#define ACCESS_EACCES_OK (1U << 0)
+int access_or_warn(const char *path, int mode, unsigned flag);
+int access_or_die(const char *path, int mode, unsigned flag);
+
+/* Warn on an inaccessible file if errno indicates this is an error */
+int warn_on_fopen_errors(const char *path);
+
+/*
+ * Open with O_NOFOLLOW, or equivalent. Note that the fallback equivalent
+ * may be racy. Do not use this as protection against an attacker who can
+ * simultaneously create paths.
+ */
+int open_nofollow(const char *path, int flags);
+
+void sleep_millisec(int millisec);
+
+/*
+ * Generate len bytes from the system cryptographically secure PRNG.
+ * Returns 0 on success and -1 on error, setting errno.  The inability to
+ * satisfy the full request is an error.
+ */
+int csprng_bytes(void *buf, size_t len);
+
 #endif /* WRAPPER_H */