# HG changeset patch # User Bruno Haible # Date 1177849015 0 # Node ID 95c5da6920cba23318abd700ac51cacea995ca80 # Parent 29e3274acedc75287a2b408e67861805866d73ed Work around fpurge bug on BSD systems. diff --git a/ChangeLog b/ChangeLog --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,16 @@ +2007-04-29 Bruno Haible + + Work around fpurge bug on BSD systems. + * modules/fpurge (Makefile.am): Compile fpurge.c unconditionally. + * m4/fpurge.m4 (gl_FUNC_FPURGE): Don't invoke AC_LIBOBJ. + * lib/fpurge.h (fpurge): Don't handle __fpurge wrapper here. Define + fpurge to rpl_fpurge if the system already has this function. + * lib/fpurge.c (fpurge): Handle also the __fpurge wrapper case and + the case where the system already has this function. Correct invariants + on BSD systems. + * lib/fseeko.c (rpl_fseeko): Update recognition of preceding fflush on + BSD systems. + 2007-04-29 Sergey Poznyakoff * lib/argp-help.c (hol_cluster_cmp): Reverse comparison. Change diff --git a/lib/fpurge.c b/lib/fpurge.c --- a/lib/fpurge.c +++ b/lib/fpurge.c @@ -20,15 +20,47 @@ /* Specification. */ #include "fpurge.h" +#if HAVE___FPURGE /* glibc >= 2.2, Solaris >= 7 */ +# include +#endif #include int fpurge (FILE *fp) { +#if HAVE___FPURGE /* glibc >= 2.2, Solaris >= 7 */ + + __fpurge (fp); + /* The __fpurge function does not have a return value. */ + return 0; + +#elif HAVE_FPURGE /* FreeBSD, NetBSD, OpenBSD, MacOS X */ + + /* Call the system's fpurge function. */ +# undef fpurge +# if !HAVE_DECL_FPURGE + extern int fpurge (FILE *); +# endif + int result = fpurge (fp); +# if defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */ + if (result == 0) + /* Correct the invariants that fpurge broke. + on BSD systems says: + "The following always hold: if _flags & __SRD, _w is 0." + If this invariant is not fulfilled and the stream is read-write but + currently writing, subsequent putc or fputc calls will write directly + into the buffer, although they shouldn't be allowed to. */ + if ((fp->_flags & __SRD) != 0) + fp->_w = 0; +# endif + return result; + +#else + /* Most systems provide FILE as a struct and the necessary bitmask in , because they need it for implementing getc() and putc() as fast macros. */ -#if defined _IO_ferror_unlocked /* GNU libc, BeOS */ +# if defined _IO_ferror_unlocked /* GNU libc, BeOS */ 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. */ @@ -38,20 +70,20 @@ fp->_IO_save_base = NULL; } return 0; -#elif defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */ +# elif defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */ fp->_p = fp->_bf._base; fp->_r = 0; - fp->_w = ((fp->_flags & (__SLBF | __SNBF)) == 0 /* fully buffered? */ + fp->_w = ((fp->_flags & (__SLBF | __SNBF | __SRD)) == 0 /* fully buffered and not currently reading? */ ? fp->_bf._size : 0); /* Avoid memory leak when there is an active ungetc buffer. */ -# if defined __NetBSD__ || defined __OpenBSD__ /* NetBSD, OpenBSD */ +# if defined __NetBSD__ || defined __OpenBSD__ /* NetBSD, OpenBSD */ /* See and */ -# define fp_ub ((struct { struct __sbuf _ub; } *) fp->_ext._base)->_ub -# else /* FreeBSD, MacOS X, Cygwin */ -# define fp_ub fp->_ub -# endif +# define fp_ub ((struct { struct __sbuf _ub; } *) fp->_ext._base)->_ub +# else /* FreeBSD, MacOS X, Cygwin */ +# define fp_ub fp->_ub +# endif if (fp_ub._base != NULL) { if (fp_ub._base != fp->_ubuf) @@ -59,12 +91,14 @@ fp_ub._base = NULL; } return 0; -#elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, mingw */ +# elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, mingw */ fp->_ptr = fp->_base; if (fp->_ptr != NULL) fp->_cnt = 0; return 0; -#else +# else #error "Please port gnulib fpurge.c to your platform! Look at the definitions of fflush, setvbuf and ungetc on your system, then report this to bug-gnulib." +# endif + #endif } diff --git a/lib/fpurge.h b/lib/fpurge.h --- a/lib/fpurge.h +++ b/lib/fpurge.h @@ -15,27 +15,25 @@ with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ +#ifndef _GL_FPURGE_H +#define _GL_FPURGE_H + #include +#ifdef __cplusplus +extern "C" { +#endif + /* Discard all pending buffered I/O on the stream STREAM. STREAM must not be wide-character oriented. Return 0 if successful. Upon error, return -1 and set errno. */ - -#if HAVE___FPURGE /* glibc >= 2.2, Solaris >= 7 */ - -# include -# define fpurge(stream) (__fpurge (stream), 0) - -#elif ! HAVE_DECL_FPURGE - -# ifdef __cplusplus -extern "C" { -# endif - +#if HAVE_FPURGE +# define fpurge rpl_fpurge +#endif extern int fpurge (FILE *stream); -# ifdef __cplusplus +#ifdef __cplusplus } -# endif +#endif -#endif +#endif /* _GL_FPURGE_H */ diff --git a/lib/fseeko.c b/lib/fseeko.c --- a/lib/fseeko.c +++ b/lib/fseeko.c @@ -46,7 +46,7 @@ # endif if (fp->_p == fp->_bf._base && fp->_r == 0 - && fp->_w == ((fp->_flags & (__SLBF | __SNBF)) == 0 /* fully buffered? */ + && fp->_w == ((fp->_flags & (__SLBF | __SNBF | __SRD)) == 0 /* fully buffered and not currently reading? */ ? fp->_bf._size : 0) && fp_ub._base == NULL) diff --git a/m4/fpurge.m4 b/m4/fpurge.m4 --- a/m4/fpurge.m4 +++ b/m4/fpurge.m4 @@ -1,4 +1,4 @@ -# fpurge.m4 serial 1 +# fpurge.m4 serial 2 dnl Copyright (C) 2007 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -9,8 +9,4 @@ AC_CHECK_FUNCS_ONCE([fpurge]) AC_CHECK_FUNCS_ONCE([__fpurge]) AC_CHECK_DECLS([fpurge], , , [#include ]) - if test $ac_cv_func_fpurge = no && test $ac_cv_func___fpurge = no; then - AC_LIBOBJ([fpurge]) - AC_CHECK_FUNCS([fpurge]) - fi ]) diff --git a/modules/fpurge b/modules/fpurge --- a/modules/fpurge +++ b/modules/fpurge @@ -12,6 +12,7 @@ gl_FUNC_FPURGE Makefile.am: +lib_SOURCES += fpurge.c Include: "fpurge.h"