diff -up m4-1.4.18/lib/fflush.c.orig m4-1.4.18/lib/fflush.c --- m4-1.4.18/lib/fflush.c.orig 2018-05-02 12:35:59.536851666 +0200 +++ m4-1.4.18/lib/fflush.c 2018-05-02 12:37:02.768958606 +0200 @@ -33,7 +33,7 @@ #undef fflush -#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ +#if defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ /* Clear the stream's ungetc buffer, preserving the value of ftello (fp). */ static void @@ -72,7 +72,7 @@ clear_ungetc_buffer (FILE *fp) #endif -#if ! (defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */) +#if ! (defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */) # if (defined __sferror || defined __DragonFly__ || defined __ANDROID__) && defined __SNPT /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Android */ @@ -148,7 +148,7 @@ rpl_fflush (FILE *stream) if (stream == NULL || ! freading (stream)) return fflush (stream); -#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ +#if defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ clear_ungetc_buffer_preserving_position (stream); diff -up m4-1.4.18/lib/fpending.c.orig m4-1.4.18/lib/fpending.c --- m4-1.4.18/lib/fpending.c.orig 2018-05-02 12:35:32.305806774 +0200 +++ m4-1.4.18/lib/fpending.c 2018-05-02 12:35:44.944827347 +0200 @@ -32,7 +32,7 @@ __fpending (FILE *fp) /* Most systems provide FILE as a struct and the necessary bitmask in <stdio.h>, because they need it for implementing getc() and putc() as fast macros. */ -#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ +#if defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ return fp->_IO_write_ptr - fp->_IO_write_base; #elif defined __sferror || defined __DragonFly__ || defined __ANDROID__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Android */ diff -up m4-1.4.18/lib/fpurge.c.orig m4-1.4.18/lib/fpurge.c --- m4-1.4.18/lib/fpurge.c.orig 2018-05-02 12:38:13.586078669 +0200 +++ m4-1.4.18/lib/fpurge.c 2018-05-02 12:38:38.785121867 +0200 @@ -62,7 +62,7 @@ fpurge (FILE *fp) /* Most systems provide FILE as a struct and the necessary bitmask in <stdio.h>, because they need it for implementing getc() and putc() as fast macros. */ -# if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ +# if defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ fp->_IO_read_end = fp->_IO_read_ptr; fp->_IO_write_ptr = fp->_IO_write_base; /* Avoid memory leak when there is an active ungetc buffer. */ diff -up m4-1.4.18/lib/freadahead.c.orig m4-1.4.18/lib/freadahead.c --- m4-1.4.18/lib/freadahead.c.orig 2016-12-31 14:54:41.000000000 +0100 +++ m4-1.4.18/lib/freadahead.c 2018-05-02 11:43:19.570336724 +0200 @@ -25,7 +25,7 @@ size_t freadahead (FILE *fp) { -#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ +#if defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ if (fp->_IO_write_ptr > fp->_IO_write_base) return 0; return (fp->_IO_read_end - fp->_IO_read_ptr) diff -up m4-1.4.18/lib/freading.c.orig m4-1.4.18/lib/freading.c --- m4-1.4.18/lib/freading.c.orig 2018-05-02 12:37:33.970011368 +0200 +++ m4-1.4.18/lib/freading.c 2018-05-02 12:37:59.393054359 +0200 @@ -31,7 +31,7 @@ freading (FILE *fp) /* Most systems provide FILE as a struct and the necessary bitmask in <stdio.h>, because they need it for implementing getc() and putc() as fast macros. */ -# if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ +# if defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ return ((fp->_flags & _IO_NO_WRITES) != 0 || ((fp->_flags & (_IO_NO_READS | _IO_CURRENTLY_PUTTING)) == 0 && fp->_IO_read_base != NULL)); diff -up m4-1.4.18/lib/fseeko.c.orig m4-1.4.18/lib/fseeko.c --- m4-1.4.18/lib/fseeko.c.orig 2018-05-02 11:44:17.947460233 +0200 +++ m4-1.4.18/lib/fseeko.c 2018-05-02 12:39:49.537216897 +0200 @@ -47,7 +47,7 @@ fseeko (FILE *fp, off_t offset, int when #endif /* These tests are based on fpurge.c. */ -#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ +#if defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ if (fp->_IO_read_end == fp->_IO_read_ptr && fp->_IO_write_ptr == fp->_IO_write_base && fp->_IO_save_base == NULL) @@ -123,7 +123,7 @@ fseeko (FILE *fp, off_t offset, int when return -1; } -#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ +#if defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ fp->_flags &= ~_IO_EOF_SEEN; fp->_offset = pos; #elif defined __sferror || defined __DragonFly__ || defined __ANDROID__ diff -up m4-1.4.18/lib/stdio-impl.h.orig m4-1.4.18/lib/stdio-impl.h --- m4-1.4.18/lib/stdio-impl.h.orig 2016-12-31 14:54:42.000000000 +0100 +++ m4-1.4.18/lib/stdio-impl.h 2018-05-02 11:43:19.570336724 +0200 @@ -18,6 +18,12 @@ the same implementation of stdio extension API, except that some fields have different naming conventions, or their access requires some casts. */ +/* Glibc 2.28 made _IO_IN_BACKUP private. For now, work around this + problem by defining it ourselves. FIXME: Do not rely on glibc + internals. */ +#if !defined _IO_IN_BACKUP && defined _IO_EOF_SEEN +# define _IO_IN_BACKUP 0x100 +#endif /* BSD stdio derived implementations. */