libsodium 1.0.6: sodium_init() marked with __attribute__ ((warn_unused_result))

[sthen]

libsodium 1.0.6 now marks sodium_init() with an attribute:

int sodium_init(void)
            __attribute__ ((warn_unused_result));

As a result, libzmq's build done with -Werror fails:

cc1plus: warnings being treated as errors
src/curve_client.cpp: In constructor 'zmq::curve_client_t::curve_client_t(const zmq::options_t&)':
src/curve_client.cpp:61: warning: ignoring return value of 'int sodium_init()', declared with attribute warn_unused_result

[xaqq]

Somehow your fix doesn't show up on the github page.

Yes it seems reasonable, though I'd personnaly prefer something like:

int ret = sodium_init();
zmq_assert(ret == 0);

I've been beaten by assert disappearing in non debug code before. (I know
that zmq_assert() is not disabled in release mode, but still).

On Tue, Nov 3, 2015 at 2:20 PM, Stuart Henderson notifications@github.com
wrote:

libsodium 1.0.6 now marks sodium_init() with an attribute:

int sodium_init(void)
attribute ((warn_unused_result));

As a result, libzmq's build done with -Werror fails:

cc1plus: warnings being treated as errors
src/curve_client.cpp: In constructor 'zmq::curve_client_t::curve_client_t(const zmq::options_t&)':
src/curve_client.cpp:61: warning: ignoring return value of 'int sodium_init()', declared with attribute warn_unused_result

Is this a reasonable fix for now?

--- src/curve_client.cpp.orig Tue Nov 3 13:11:25 2015
+++ src/curve_client.cpp Tue Nov 3 13:12:29 2015
@@ -57,8 +57,7 @@ zmq::curve_client_t::curve_client_t (const options_t &
unsigned char tmpbytes[4];
randombytes(tmpbytes, 4);
#else

• // todo check return code

• sodium_init();

• zmq_assert (sodium_init() == 0);
  #endif

  // Generate short-term key pair
  --- src/curve_server.cpp.orig Tue Nov 3 13:12:52 2015
  +++ src/curve_server.cpp Tue Nov 3 13:13:18 2015
  @@ -60,8 +60,7 @@ zmq::curve_server_t::curve_server_t (session_base_t *s
  unsigned char tmpbytes[4];
  randombytes(tmpbytes, 4);
  #else

• // todo check return code

• sodium_init();

• zmq_assert (sodium_init() == 0);
  #endif

  // Generate short-term key pair

—
Reply to this email directly or view it on GitHub
#1632.

Kapp Arnaud - Xaqq

[sthen]

Ah I edited the post to remove the fix as it triggers an abort in the tests, so I wasn't sure what else needed doing ;)

[xaqq]

Okay, I believe I know why.

sodium_init() can be called multiple time, however if the library was
already initialized it will return 1 instead of 0.

"sodium_init() returns 0 on success, -1 on failure, and 1 is the library
had already been initialized." from
http://doc.libsodium.org/usage/index.html

On Tue, Nov 3, 2015 at 3:39 PM, Stuart Henderson notifications@github.com
wrote:

Ah I edited the post to remove the fix as it triggers an abort in the
tests, so I wasn't sure what else needed doing ;)

—
Reply to this email directly or view it on GitHub
#1632 (comment).

Kapp Arnaud - Xaqq

[sthen]

So this does the trick, or it could just check for != -1 ..

Index: patch-src_curve_client_cpp
===================================================================
RCS file: patch-src_curve_client_cpp
diff -N patch-src_curve_client_cpp
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ patch-src_curve_client_cpp  3 Nov 2015 16:38:21 -0000
@@ -0,0 +1,14 @@
+--- src/curve_client.cpp.orig  Tue Nov  3 16:35:06 2015
++++ src/curve_client.cpp   Tue Nov  3 16:36:32 2015
+@@ -57,8 +57,8 @@ zmq::curve_client_t::curve_client_t (const options_t &
+     unsigned char tmpbytes[4];
+     randombytes(tmpbytes, 4);
+ #else
+-    // todo check return code
+-    sodium_init();
++    const int ret = sodium_init();
++    zmq_assert ((ret == 0) || (ret == 1));
+ #endif
+ 
+     //  Generate short-term key pair
Index: patch-src_curve_server_cpp
===================================================================
RCS file: patch-src_curve_server_cpp
diff -N patch-src_curve_server_cpp
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ patch-src_curve_server_cpp  3 Nov 2015 16:38:21 -0000
@@ -0,0 +1,14 @@
+--- src/curve_server.cpp.orig  Tue Nov  3 16:35:06 2015
++++ src/curve_server.cpp   Tue Nov  3 16:36:49 2015
+@@ -60,8 +60,8 @@ zmq::curve_server_t::curve_server_t (session_base_t *s
+     unsigned char tmpbytes[4];
+     randombytes(tmpbytes, 4);
+ #else
+-    // todo check return code
+-    sodium_init();
++    const int ret = sodium_init();
++    zmq_assert ((ret == 0) || (ret == 1));
+ #endif
+ 
+     //  Generate short-term key pair

[c-rack]

Please correct me if I am wrong, but this has been in libzmq since 479db21 (about a year ago).
@sthen which version of libzmq are you using?

[hintjens]

Backported to 4-1. I'm closing this issue now.