We've hit this failure a few times in pkgsrc with packages which embed gnulib,
an example being the latest gnutls:
../../src/gl/stdio.h:1034:1: error: 'char* gets(char*)' conflicts with a
previous declaration
_GL_WARN_ON_USE (gets, "gets is a security hole - use fgets instead");
^
/opt/tools/gcc49/lib/gcc/x86_64-sun-solaris2.11/4.9.2/include-fixed/iso/stdio_iso.h:259:14:
note: previous declaration 'char* std::gets(char*)'
extern char *gets(char *);
^
Full build log is here:
http://us-east.manta.joyent.com/pkgsrc/public/reports/upstream-trunk32/20150602.2233/gnutls-3.3.15/build.log
We've fixed it a few different ways over time:
https://github.com/joyent/pkgsrc/blob/joyent/release/2015Q1/devel/m4/patches/patch-lib_stdio.in.h
https://github.com/joyent/pkgsrc/blob/joyent/release/2015Q1/math/octave/patches/patch-libgnu_stdio.in.h
https://github.com/joyent/pkgsrc/blob/joyent/release/2015Q1/security/gnutls/patches/patch-gl_stdio.in.h
but the cleanest fix appears to be the last, so I am proposing it here for
inclusion upstream.
Regards,
--
Jonathan Perkin - Joyent, Inc. - www.joyent.com
diff --git a/lib/stdio.in.h b/lib/stdio.in.h
index fa6b595..55f9653 100644
--- a/lib/stdio.in.h
+++ b/lib/stdio.in.h
@@ -719,15 +719,16 @@ _GL_WARN_ON_USE (getline, "getline is unportable - "
# endif
#endif
+#if !defined __cplusplus
/* It is very rare that the developer ever has full control of stdin,
so any use of gets warrants an unconditional warning; besides, C11
removed it. */
-#undef gets
-#if HAVE_RAW_DECL_GETS
+# undef gets
+# if HAVE_RAW_DECL_GETS
_GL_WARN_ON_USE (gets, "gets is a security hole - use fgets instead");
+# endif
#endif
-
#if @GNULIB_OBSTACK_PRINTF@ || @GNULIB_OBSTACK_PRINTF_POSIX@
struct obstack;
/* Grow an obstack with formatted output. Return the number of
