Support non-blocking pipe I/O in read() on native Windows.

* lib/unistd.in.h: Include <sys/types.h> also for 'read'.
(read): New declaration.
* lib/read.c: New file.
* lib/stdio.in.h (_GL_ATTRIBUTE_FORMAT_SCANF,
_GL_ATTRIBUTE_FORMAT_SCANF_SYSTEM): New macros.
(fgetc, fgets, fread, fscanf, getc, getchar, gets, scanf, vfscanf,
vscanf): New declarations.
* lib/stdio-read.c: New file.
* m4/read.m4: New file.
* m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Initialize GNULIB_READ,
REPLACE_READ.
* m4/stdio_h.m4 (gl_STDIO_H): Set GNULIB_FGETC, GNULIB_FGETS,
GNULIB_FREAD, GNULIB_FSCANF, GNULIB_GETC, GNULIB_GETCHAR, GNULIB_GETS,
GNULIB_SCANF, GNULIB_VFSCANF, GNULIB_VSCANF. In non-blocking I/O is
desired and needs workarounds, set REPLACE_STDIO_READ_FUNCS.
(gl_STDIO_H_DEFAULTS): Initialize GNULIB_FGETC, GNULIB_FGETS,
GNULIB_FREAD, GNULIB_FSCANF, GNULIB_GETC, GNULIB_GETCHAR, GNULIB_GETS,
GNULIB_SCANF, GNULIB_VFSCANF, GNULIB_VSCANF, REPLACE_STDIO_READ_FUNCS.
* modules/read: New file.
* modules/nonblocking (Files): Add lib/stdio-read.c.
* modules/unistd (Makefile.am): Substitute GNULIB_READ, REPLACE_READ.
* modules/stdio (Makefile.am): Substitute GNULIB_FGETC, GNULIB_FGETS,
GNULIB_FREAD, GNULIB_FSCANF, GNULIB_GETC, GNULIB_GETCHAR, GNULIB_GETS,
GNULIB_SCANF, GNULIB_VFSCANF, GNULIB_VSCANF, REPLACE_STDIO_READ_FUNCS.
* modules/pread (Depends-on): Add read.
* modules/safe-read (Depends-on): Likewise.
* tests/test-stdio-c++.cc (fgetc, fgets, fread, fscanf, getc, getchar,
gets, scanf, vfscanf, vscanf): Verify signatures.
* doc/posix-functions/read.texi: Mention 'nonblocking' module and
problem with non-blocking pipes.
* doc/posix-functions/fgetc.texi: Likewise.
* doc/posix-functions/fgets.texi: Likewise.
* doc/posix-functions/fread.texi: Likewise.
* doc/posix-functions/fscanf.texi: Likewise.
* doc/posix-functions/getc.texi: Likewise.
* doc/posix-functions/getchar.texi: Likewise.
* doc/posix-functions/gets.texi: Likewise.
* doc/posix-functions/scanf.texi: Likewise.
* doc/posix-functions/vfscanf.texi: Likewise.
* doc/posix-functions/vscanf.texi: Likewise.

4 files changed, 423 insertions, 6 deletions

diff --git a/lib/read.c b/lib/read.c
new file mode 100644
index 0000000000..21b90db675
--- /dev/null
+++ b/lib/read.c
@@ -0,0 +1,59 @@
+/* POSIX compatible read() function.
+   Copyright (C) 2008-2011 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2011.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <unistd.h>
+
+/* Replace this function only if module 'nonblocking' is requested.  */
+#if GNULIB_NONBLOCKING
+
+# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+
+#  include <errno.h>
+#  include <io.h>
+
+#  define WIN32_LEAN_AND_MEAN  /* avoid including junk */
+#  include <windows.h>
+
+ssize_t
+rpl_read (int fd, void *buf, size_t count)
+#undef read
+{
+  ssize_t ret = read (fd, buf, count);
+
+  if (ret < 0
+      && GetLastError () == ERROR_NO_DATA)
+    {
+      HANDLE h = (HANDLE) _get_osfhandle (fd);
+      if (GetFileType (h) == FILE_TYPE_PIPE)
+        {
+          /* h is a pipe or socket.  */
+          DWORD state;
+          if (GetNamedPipeHandleState (h, &state, NULL, NULL, NULL, NULL, 0)
+              && (state & PIPE_NOWAIT) != 0)
+            /* h is a pipe in non-blocking mode.
+               Change errno from EINVAL to EAGAIN.  */
+            errno = EAGAIN;
+        }
+    }
+  return ret;
+}
+
+# endif
+#endif
diff --git a/lib/stdio-read.c b/lib/stdio-read.c
new file mode 100644
index 0000000000..d7901dd676
--- /dev/null
+++ b/lib/stdio-read.c
@@ -0,0 +1,148 @@
+/* POSIX compatible FILE stream read function.
+   Copyright (C) 2008-2011 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2011.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <stdio.h>
+
+/* Replace these functions only if module 'nonblocking' is requested.  */
+#if GNULIB_NONBLOCKING
+
+/* On native Windows platforms, when read() is called on a non-blocking pipe
+   with an empty buffer, ReadFile() fails with error GetLastError() =
+   ERROR_NO_DATA, and read() in consequence fails with error EINVAL.  This
+   read() function is at the basis of the function which fills the buffer of
+   a FILE stream.  */
+
+# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+
+#  include <errno.h>
+#  include <io.h>
+
+#  define WIN32_LEAN_AND_MEAN  /* avoid including junk */
+#  include <windows.h>
+
+#  define CALL_WITH_ERRNO_FIX(RETTYPE, EXPRESSION, FAILED) \
+  if (ferror (stream))                                                        \
+    return (EXPRESSION);                                                      \
+  else                                                                        \
+    {                                                                         \
+      RETTYPE ret;                                                            \
+      SetLastError (0);                                                       \
+      ret = (EXPRESSION);                                                     \
+      if (FAILED)                                                             \
+        {                                                                     \
+          if (GetLastError () == ERROR_NO_DATA && ferror (stream))            \
+            {                                                                 \
+              int fd = fileno (stream);                                       \
+              if (fd >= 0)                                                    \
+                {                                                             \
+                  HANDLE h = (HANDLE) _get_osfhandle (fd);                    \
+                  if (GetFileType (h) == FILE_TYPE_PIPE)                      \
+                    {                                                         \
+                      /* h is a pipe or socket.  */                           \
+                      DWORD state;                                            \
+                      if (GetNamedPipeHandleState (h, &state, NULL, NULL,     \
+                                                   NULL, NULL, 0)             \
+                          && (state & PIPE_NOWAIT) != 0)                      \
+                        /* h is a pipe in non-blocking mode.                  \
+                           Change errno from EINVAL to EAGAIN.  */            \
+                        errno = EAGAIN;                                       \
+                    }                                                         \
+                }                                                             \
+            }                                                                 \
+        }                                                                     \
+      return ret;                                                             \
+    }
+
+int
+scanf (const char *format, ...)
+{
+  int retval;
+  va_list args;
+
+  va_start (args, format);
+  retval = vfscanf (stdin, format, args);
+  va_end (args);
+
+  return retval;
+}
+
+int
+fscanf (FILE *stream, const char *format, ...)
+{
+  int retval;
+  va_list args;
+
+  va_start (args, format);
+  retval = vfscanf (stream, format, args);
+  va_end (args);
+
+  return retval;
+}
+
+int
+vscanf (const char *format, va_list args)
+{
+  return vfscanf (stdin, format, args);
+}
+
+int
+vfscanf (FILE *stream, const char *format, va_list args)
+#undef vfscanf
+{
+  CALL_WITH_ERRNO_FIX (int, vfscanf (stream, format, args), ret == EOF)
+}
+
+int
+getchar (void)
+{
+  return fgetc (stdin);
+}
+
+int
+fgetc (FILE *stream)
+#undef fgetc
+{
+  CALL_WITH_ERRNO_FIX (int, fgetc (stream), ret == EOF)
+}
+
+char *
+fgets (char *s, int n, FILE *stream)
+#undef fgets
+{
+  CALL_WITH_ERRNO_FIX (char *, fgets (s, n, stream), ret == NULL)
+}
+
+char *
+gets (char *s)
+#undef gets
+{
+  FILE *stream = stdin;
+  CALL_WITH_ERRNO_FIX (char *, gets (s), ret == NULL)
+}
+
+size_t
+fread (void *ptr, size_t s, size_t n, FILE *stream)
+#undef fread
+{
+  CALL_WITH_ERRNO_FIX (size_t, fread (ptr, s, n, stream), ret < n)
+}
+
+# endif
+#endif
diff --git a/lib/stdio.in.h b/lib/stdio.in.h
index c209d6f904..79e7f7d8aa 100644
--- a/lib/stdio.in.h
+++ b/lib/stdio.in.h
@@ -87,6 +87,25 @@
 #define _GL_ATTRIBUTE_FORMAT_PRINTF_SYSTEM(formatstring_parameter, first_argument) \
   _GL_ATTRIBUTE_FORMAT ((__printf__, formatstring_parameter, first_argument))
 
+/* _GL_ATTRIBUTE_FORMAT_SCANF
+   indicates to GCC that the function takes a format string and arguments,
+   where the format string directives are the ones standardized by ISO C99
+   and POSIX.  */
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4)
+# define _GL_ATTRIBUTE_FORMAT_SCANF(formatstring_parameter, first_argument) \
+   _GL_ATTRIBUTE_FORMAT ((__gnu_scanf__, formatstring_parameter, first_argument))
+#else
+# define _GL_ATTRIBUTE_FORMAT_SCANF(formatstring_parameter, first_argument) \
+   _GL_ATTRIBUTE_FORMAT ((__scanf__, formatstring_parameter, first_argument))
+#endif
+
+/* _GL_ATTRIBUTE_FORMAT_SCANF_SYSTEM is like _GL_ATTRIBUTE_FORMAT_SCANF,
+   except that it indicates to GCC that the supported format string directives
+   are the ones of the system scanf(), rather than the ones standardized by
+   ISO C99 and POSIX.  */
+#define _GL_ATTRIBUTE_FORMAT_SCANF_SYSTEM(formatstring_parameter, first_argument) \
+  _GL_ATTRIBUTE_FORMAT ((__scanf__, formatstring_parameter, first_argument))
+
 /* Solaris 10 declares renameat in <unistd.h>, not in <stdio.h>.  */
 /* But in any case avoid namespace pollution on glibc systems.  */
 #if (@GNULIB_RENAMEAT@ || defined GNULIB_POSIXCHECK) && defined __sun \
@@ -175,11 +194,34 @@ _GL_WARN_ON_USE (fflush, "fflush is not always POSIX compliant - "
                  "use gnulib module fflush for portable POSIX compliance");
 #endif
 
-/* It is very rare that the developer ever has full control of stdin,
-   so any use of gets warrants an unconditional warning.  Assume it is
-   always declared, since it is required by C89.  */
-#undef gets
-_GL_WARN_ON_USE (gets, "gets is a security hole - use fgets instead");
+#if @GNULIB_FGETC@
+# if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fgetc
+#   define fgetc rpl_fgetc
+#  endif
+_GL_FUNCDECL_RPL (fgetc, int, (FILE *stream) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (fgetc, int, (FILE *stream));
+# else
+_GL_CXXALIAS_SYS (fgetc, int, (FILE *stream));
+# endif
+_GL_CXXALIASWARN (fgetc);
+#endif
+
+#if @GNULIB_FGETS@
+# if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fgets
+#   define fgets rpl_fgets
+#  endif
+_GL_FUNCDECL_RPL (fgets, char *, (char *s, int n, FILE *stream)
+                                 _GL_ARG_NONNULL ((1, 3)));
+_GL_CXXALIAS_RPL (fgets, char *, (char *s, int n, FILE *stream));
+# else
+_GL_CXXALIAS_SYS (fgets, char *, (char *s, int n, FILE *stream));
+# endif
+_GL_CXXALIASWARN (fgets);
+#endif
 
 #if @GNULIB_FOPEN@
 # if @REPLACE_FOPEN@
@@ -290,6 +332,21 @@ _GL_CXXALIAS_SYS (fputs, int, (const char *string, FILE *stream));
 _GL_CXXALIASWARN (fputs);
 #endif
 
+#if @GNULIB_FREAD@
+# if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fread
+#   define fread rpl_fread
+#  endif
+_GL_FUNCDECL_RPL (fread, size_t, (void *ptr, size_t s, size_t n, FILE *stream)
+                                 _GL_ARG_NONNULL ((4)));
+_GL_CXXALIAS_RPL (fread, size_t, (void *ptr, size_t s, size_t n, FILE *stream));
+# else
+_GL_CXXALIAS_SYS (fread, size_t, (void *ptr, size_t s, size_t n, FILE *stream));
+# endif
+_GL_CXXALIASWARN (fread);
+#endif
+
 #if @GNULIB_FREOPEN@
 # if @REPLACE_FREOPEN@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -314,6 +371,22 @@ _GL_WARN_ON_USE (freopen,
                  "use gnulib module freopen for portability");
 #endif
 
+#if @GNULIB_FSCANF@
+# if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fscanf
+#   define fscanf rpl_fscanf
+#  endif
+_GL_FUNCDECL_RPL (fscanf, int, (FILE *stream, const char *format, ...)
+                               _GL_ATTRIBUTE_FORMAT_SCANF_SYSTEM (2, 3)
+                               _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_RPL (fscanf, int, (FILE *stream, const char *format, ...));
+# else
+_GL_CXXALIAS_SYS (fscanf, int, (FILE *stream, const char *format, ...));
+# endif
+_GL_CXXALIASWARN (fscanf);
+#endif
+
 
 /* Set up the following warnings, based on which modules are in use.
    GNU Coding Standards discourage the use of fseek, since it imposes
@@ -540,6 +613,34 @@ rpl_fwrite (const void *ptr, size_t s, size_t n, FILE *stream)
 _GL_CXXALIASWARN (fwrite);
 #endif
 
+#if @GNULIB_GETC@
+# if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef getc
+#   define getc rpl_fgetc
+#  endif
+_GL_FUNCDECL_RPL (fgetc, int, (FILE *stream) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL_1 (getc, rpl_fgetc, int, (FILE *stream));
+# else
+_GL_CXXALIAS_SYS (getc, int, (FILE *stream));
+# endif
+_GL_CXXALIASWARN (getc);
+#endif
+
+#if @GNULIB_GETCHAR@
+# if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef getchar
+#   define getchar rpl_getchar
+#  endif
+_GL_FUNCDECL_RPL (getchar, int, (void));
+_GL_CXXALIAS_RPL (getchar, int, (void));
+# else
+_GL_CXXALIAS_SYS (getchar, int, (void));
+# endif
+_GL_CXXALIASWARN (getchar);
+#endif
+
 #if @GNULIB_GETDELIM@
 /* Read input, up to (and including) the next occurrence of DELIMITER, from
    STREAM, store it in *LINEPTR (and NUL-terminate it).
@@ -616,6 +717,26 @@ _GL_WARN_ON_USE (getline, "getline is unportable - "
 # endif
 #endif
 
+#if @GNULIB_GETS@
+# if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef gets
+#   define gets rpl_gets
+#  endif
+_GL_FUNCDECL_RPL (gets, char *, (char *s) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (gets, char *, (char *s));
+# else
+_GL_CXXALIAS_SYS (gets, char *, (char *s));
+#  undef gets
+# endif
+_GL_CXXALIASWARN (gets);
+/* It is very rare that the developer ever has full control of stdin,
+   so any use of gets warrants an unconditional warning.  Assume it is
+   always declared, since it is required by C89.  */
+_GL_WARN_ON_USE (gets, "gets is a security hole - use fgets instead");
+#endif
+
+
 #if @GNULIB_OBSTACK_PRINTF@ || @GNULIB_OBSTACK_PRINTF_POSIX@
 struct obstack;
 /* Grow an obstack with formatted output.  Return the number of
@@ -872,6 +993,37 @@ _GL_WARN_ON_USE (renameat, "renameat is not portable - "
 # endif
 #endif
 
+#if @GNULIB_SCANF@
+# if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
+#  if defined __GNUC__
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    undef scanf
+/* Don't break __attribute__((format(scanf,M,N))).  */
+#    define scanf __scanf__
+#   endif
+_GL_FUNCDECL_RPL_1 (__scanf__, int,
+                    (const char *format, ...)
+                    __asm__ (@ASM_SYMBOL_PREFIX@
+                             _GL_STDIO_MACROEXPAND_AND_STRINGIZE(rpl_scanf))
+                    _GL_ATTRIBUTE_FORMAT_SCANF_SYSTEM (1, 2)
+                    _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL_1 (scanf, __scanf__, int, (const char *format, ...));
+#  else
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    undef scanf
+#    define scanf rpl_scanf
+#   endif
+_GL_FUNCDECL_RPL (scanf, int, (const char *format, ...)
+                              _GL_ATTRIBUTE_FORMAT_SCANF_SYSTEM (1, 2)
+                              _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (scanf, int, (const char *format, ...));
+#  endif
+# else
+_GL_CXXALIAS_SYS (scanf, int, (const char *format, ...));
+# endif
+_GL_CXXALIASWARN (scanf);
+#endif
+
 #if @GNULIB_SNPRINTF@
 # if @REPLACE_SNPRINTF@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -1065,6 +1217,25 @@ _GL_WARN_ON_USE (vfprintf, "vfprintf is not always POSIX compliant - "
                       "POSIX compliance");
 #endif
 
+#if @GNULIB_VFSCANF@
+# if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef vfscanf
+#   define vfscanf rpl_vfscanf
+#  endif
+_GL_FUNCDECL_RPL (vfscanf, int,
+                  (FILE *stream, const char *format, va_list args)
+                  _GL_ATTRIBUTE_FORMAT_SCANF_SYSTEM (2, 0)
+                  _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_RPL (vfscanf, int,
+                  (FILE *stream, const char *format, va_list args));
+# else
+_GL_CXXALIAS_SYS (vfscanf, int,
+                  (FILE *stream, const char *format, va_list args));
+# endif
+_GL_CXXALIASWARN (vfscanf);
+#endif
+
 #if @GNULIB_VPRINTF_POSIX@ || @GNULIB_VPRINTF@
 # if (@GNULIB_VPRINTF_POSIX@ && @REPLACE_VPRINTF@) \
      || (@GNULIB_VPRINTF@ && @REPLACE_STDIO_WRITE_FUNCS@ && (@GNULIB_STDIO_H_NONBLOCKING@ || @GNULIB_STDIO_H_SIGPIPE@))
@@ -1100,6 +1271,22 @@ _GL_WARN_ON_USE (vprintf, "vprintf is not always POSIX compliant - "
                  "POSIX compliance");
 #endif
 
+#if @GNULIB_VSCANF@
+# if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef vscanf
+#   define vscanf rpl_vscanf
+#  endif
+_GL_FUNCDECL_RPL (vscanf, int, (const char *format, va_list args)
+                               _GL_ATTRIBUTE_FORMAT_SCANF_SYSTEM (1, 0)
+                               _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (vscanf, int, (const char *format, va_list args));
+# else
+_GL_CXXALIAS_SYS (vscanf, int, (const char *format, va_list args));
+# endif
+_GL_CXXALIASWARN (vscanf);
+#endif
+
 #if @GNULIB_VSNPRINTF@
 # if @REPLACE_VSNPRINTF@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index 10245c42eb..d216e38515 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -97,7 +97,8 @@
 # include <netdb.h>
 #endif
 
-#if (@GNULIB_WRITE@ || @GNULIB_READLINK@ || @GNULIB_READLINKAT@ \
+#if (@GNULIB_READ@ || @GNULIB_WRITE@ \
+     || @GNULIB_READLINK@ || @GNULIB_READLINKAT@ \
      || @GNULIB_PREAD@ || @GNULIB_PWRITE@ || defined GNULIB_POSIXCHECK)
 /* Get ssize_t.  */
 # include <sys/types.h>
@@ -1105,6 +1106,28 @@ _GL_WARN_ON_USE (pwrite, "pwrite is unportable - "
 #endif
 
 
+#if @GNULIB_READ@
+/* Read up to COUNT bytes from file descriptor FD into the buffer starting
+   at BUF.  See the POSIX:2001 specification
+   <http://www.opengroup.org/susv3xsh/read.html>.  */
+# if @REPLACE_READ@ && @GNULIB_UNISTD_H_NONBLOCKING@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef read
+#   define read rpl_read
+#  endif
+_GL_FUNCDECL_RPL (read, ssize_t, (int fd, void *buf, size_t count)
+                                 _GL_ARG_NONNULL ((2)));
+_GL_CXXALIAS_RPL (read, ssize_t, (int fd, void *buf, size_t count));
+# else
+/* Need to cast, because on mingw, the third parameter is
+                                                          unsigned int count
+   and the return type is 'int'.  */
+_GL_CXXALIAS_SYS_CAST (read, ssize_t, (int fd, void *buf, size_t count));
+# endif
+_GL_CXXALIASWARN (read);
+#endif
+
+
 #if @GNULIB_READLINK@
 /* Read the contents of the symbolic link FILE and place the first BUFSIZE
    bytes of it into BUF.  Return the number of bytes placed into BUF if