[PATCH] stdio: don't assume gets any more

[Eric Blake]

Gnulib intentionally does not have a gets module, and now that C11
and glibc have dropped it, we should be more proactive about warning
any user on a platform that still has a declaration of this dangerous
interface.

* m4/stdio_h.m4 (gl_STDIO_H, gl_STDIO_H_DEFAULTS): Drop gets
support.
* lib/stdio.in.h (gets): Make warning occur in more places.
Reported by Christer Solskogen.

Signed-off-by: Eric Blake <address@hidden>
---

Any thoughts before I push this?

 ChangeLog      |    7 +++++++
 lib/stdio.in.h |   20 ++++----------------
 m4/stdio_h.m4  |   10 ++++------
 3 files changed, 15 insertions(+), 22 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index d74544a..3ef5d84 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2012-03-29  Eric Blake  <address@hidden>
+
+       stdio: don't assume gets any more
+       * m4/stdio_h.m4 (gl_STDIO_H, gl_STDIO_H_DEFAULTS): Drop gets
+       support.
+       * lib/stdio.in.h (gets): Make warning occur in more places.
+
 2012-03-25  Bruno Haible  <address@hidden>

        Tests for module 'localeconv'.
diff --git a/lib/stdio.in.h b/lib/stdio.in.h
index aa7b599..ac150b1 100644
--- a/lib/stdio.in.h
+++ b/lib/stdio.in.h
@@ -698,26 +698,14 @@ _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.  */
+   so any use of gets warrants an unconditional warning; besides, C11
+   removed it.  */
+#undef gets
+#if HAVE_RAW_DECL_GETS
 _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
diff --git a/m4/stdio_h.m4 b/m4/stdio_h.m4
index 1973e8d..b03393b 100644
--- a/m4/stdio_h.m4
+++ b/m4/stdio_h.m4
@@ -1,4 +1,4 @@
-# stdio_h.m4 serial 40
+# stdio_h.m4 serial 41
 dnl Copyright (C) 2007-2012 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -18,7 +18,6 @@ AC_DEFUN([gl_STDIO_H],
   GNULIB_GETC=1
   GNULIB_GETCHAR=1
   GNULIB_FGETS=1
-  GNULIB_GETS=1
   GNULIB_FREAD=1
   dnl This ifdef is necessary to avoid an error "missing file lib/stdio-read.c"
   dnl "expected source file, required through AC_LIBSOURCES, not found". It is
@@ -72,10 +71,10 @@ AC_DEFUN([gl_STDIO_H],

   dnl Check for declarations of anything we want to poison if the
   dnl corresponding gnulib module is not in use, and which is not
-  dnl guaranteed by C89.
+  dnl guaranteed by both C89 and C11.
   gl_WARN_ON_USE_PREPARE([[#include <stdio.h>
-    ]], [dprintf fpurge fseeko ftello getdelim getline pclose popen renameat
-    snprintf tmpfile vdprintf vsnprintf])
+    ]], [dprintf fpurge fseeko ftello getdelim getline gets pclose popen
+    renameat snprintf tmpfile vdprintf vsnprintf])
 ])

 AC_DEFUN([gl_STDIO_MODULE_INDICATOR],
@@ -113,7 +112,6 @@ AC_DEFUN([gl_STDIO_H_DEFAULTS],
   GNULIB_GETCHAR=0;              AC_SUBST([GNULIB_GETCHAR])
   GNULIB_GETDELIM=0;             AC_SUBST([GNULIB_GETDELIM])
   GNULIB_GETLINE=0;              AC_SUBST([GNULIB_GETLINE])
-  GNULIB_GETS=0;                 AC_SUBST([GNULIB_GETS])
   GNULIB_OBSTACK_PRINTF=0;       AC_SUBST([GNULIB_OBSTACK_PRINTF])
   GNULIB_OBSTACK_PRINTF_POSIX=0; AC_SUBST([GNULIB_OBSTACK_PRINTF_POSIX])
   GNULIB_PCLOSE=0;               AC_SUBST([GNULIB_PCLOSE])
-- 
1.7.7.6