Commit 5df28c15 authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Paul E. McKenney
Browse files

tools/nolibc: implement fd-based FILE streams 



This enables the usage of the stream APIs with arbitrary filedescriptors.

It will be used by a future testcase.

Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent e8842cf0

tools/include/nolibc/stdio.h

+68 −27
Original line number Diff line number Diff line
@@ -21,17 +21,75 @@ 
#define EOF (-1)

#endif



/* just define FILE as a non-empty type */

/* just define FILE as a non-empty type. The value of the pointer gives

 * the FD: FILE=~fd for fd>=0 or NULL for fd<0. This way positive FILE

 * are immediately identified as abnormal entries (i.e. possible copies

 * of valid pointers to something else).

 */

typedef struct FILE {

	char dummy[1];

} FILE;



/* We define the 3 common stdio files as constant invalid pointers that

 * are easily recognized.

 */

static __attribute__((unused)) FILE* const stdin  = (FILE*)-3;

static __attribute__((unused)) FILE* const stdout = (FILE*)-2;

static __attribute__((unused)) FILE* const stderr = (FILE*)-1;

static __attribute__((unused)) FILE* const stdin  = (FILE*)(intptr_t)~STDIN_FILENO;

static __attribute__((unused)) FILE* const stdout = (FILE*)(intptr_t)~STDOUT_FILENO;

static __attribute__((unused)) FILE* const stderr = (FILE*)(intptr_t)~STDERR_FILENO;



/* provides a FILE* equivalent of fd. The mode is ignored. */

static __attribute__((unused))

FILE *fdopen(int fd, const char *mode __attribute__((unused)))

{

	if (fd < 0) {

		SET_ERRNO(EBADF);

		return NULL;

	}

	return (FILE*)(intptr_t)~fd;

}



/* provides the fd of stream. */

static __attribute__((unused))

int fileno(FILE *stream)

{

	intptr_t i = (intptr_t)stream;



	if (i >= 0) {

		SET_ERRNO(EBADF);

		return -1;

	}

	return ~i;

}



/* flush a stream. */

static __attribute__((unused))

int fflush(FILE *stream)

{

	intptr_t i = (intptr_t)stream;



	/* NULL is valid here. */

	if (i > 0) {

		SET_ERRNO(EBADF);

		return -1;

	}



	/* Don't do anything, nolibc does not support buffering. */

	return 0;

}



/* flush a stream. */

static __attribute__((unused))

int fclose(FILE *stream)

{

	intptr_t i = (intptr_t)stream;



	if (i >= 0) {

		SET_ERRNO(EBADF);

		return -1;

	}



	if (close(~i))

		return EOF;



	return 0;

}



/* getc(), fgetc(), getchar() */
@@ -41,14 +99,8 @@ static __attribute__((unused)) 
int fgetc(FILE* stream)

{

	unsigned char ch;

	int fd;



	if (stream < stdin || stream > stderr)

		return EOF;



	fd = 3 + (long)stream;



	if (read(fd, &ch, 1) <= 0)

	if (read(fileno(stream), &ch, 1) <= 0)

		return EOF;

	return ch;

}
@@ -68,14 +120,8 @@ static __attribute__((unused)) 
int fputc(int c, FILE* stream)

{

	unsigned char ch = c;

	int fd;



	if (stream < stdin || stream > stderr)

		return EOF;



	fd = 3 + (long)stream;



	if (write(fd, &ch, 1) <= 0)

	if (write(fileno(stream), &ch, 1) <= 0)

		return EOF;

	return ch;

}
@@ -96,12 +142,7 @@ static __attribute__((unused)) 
int _fwrite(const void *buf, size_t size, FILE *stream)

{

	ssize_t ret;

	int fd;



	if (stream < stdin || stream > stderr)

		return EOF;



	fd = 3 + (long)stream;

	int fd = fileno(stream);



	while (size) {

		ret = write(fd, buf, size);