Resolve deprecation warnings

[mikeokner]

Latest builds on Travis are throwing deprecation warnings:

$ npm install
> posix-mq@1.1.1 install /home/travis/build/mikeokner/posix-mq
> node-gyp rebuild
make: Entering directory `/home/travis/build/mikeokner/posix-mq/build'
  CXX(target) Release/obj.target/posixmq/src/posixmq.o
In file included from ../src/posixmq.cc:19:0:
../node_modules/nan/nan.h: In constructor ‘Nan::Utf8String::Utf8String(v8::Local<v8::Value>)’:
../node_modules/nan/nan.h:1064:78: warning: ‘v8::Local<v8::String> v8::Value::ToString(v8::Isolate*) const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:2537): Use maybe version [-Wdeprecated-declarations]
       v8::Local<v8::String> string = from->ToString(v8::Isolate::GetCurrent());
                                                                              ^
../src/posixmq.cc: In static member function ‘static void PosixMQ::poll_cb(uv_poll_t*, int, int)’:
../src/posixmq.cc:113:75: warning: ‘v8::Local<v8::Value> Nan::MakeCallback(v8::Local<v8::Object>, v8::Local<v8::Function>, int, v8::Local<v8::Value>*)’ is deprecated (declared at ../node_modules/nan/nan.h:958) [-Wdeprecated-declarations]
             Nan::MakeCallback(obj->handle(), emit, 1, read_emit_argv_local);
                                                                           ^
../src/posixmq.cc:130:76: warning: ‘v8::Local<v8::Value> Nan::MakeCallback(v8::Local<v8::Object>, v8::Local<v8::Function>, int, v8::Local<v8::Value>*)’ is deprecated (declared at ../node_modules/nan/nan.h:958) [-Wdeprecated-declarations]
             Nan::MakeCallback(obj->handle(), emit, 1, write_emit_argv_local);
                                                                            ^
../src/posixmq.cc: In static member function ‘static void PosixMQ::Open(const Nan::FunctionCallbackInfo<v8::Value>&)’:
../src/posixmq.cc:185:58: warning: ‘v8::Local<v8::Object> v8::Value::ToObject() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:10254): Use maybe version [-Wdeprecated-declarations]
         v8::Local<v8::Object> config = info[0]->ToObject();
                                                          ^
../src/posixmq.cc:195:42: warning: ‘bool v8::Value::BooleanValue() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:2568): Use maybe version [-Wdeprecated-declarations]
             doCreate = val->BooleanValue();
                                          ^
../src/posixmq.cc:202:42: warning: ‘uint32_t v8::Value::Uint32Value() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:2571): Use maybe version [-Wdeprecated-declarations]
                 flags = val->Uint32Value();
                                          ^
../src/posixmq.cc:225:49: warning: ‘uint32_t v8::Value::Uint32Value() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:2571): Use maybe version [-Wdeprecated-declarations]
                 mode = (mode_t)val->Uint32Value();
                                                 ^
../src/posixmq.cc:239:55: warning: ‘bool v8::Value::BooleanValue() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:2568): Use maybe version [-Wdeprecated-declarations]
             if (val->IsBoolean() && val->BooleanValue() == true) {
                                                       ^
../src/posixmq.cc:246:59: warning: ‘uint32_t v8::Value::Uint32Value() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:2571): Use maybe version [-Wdeprecated-declarations]
                 obj->mqattrs.mq_maxmsg = val->Uint32Value();
                                                           ^
../src/posixmq.cc:254:60: warning: ‘uint32_t v8::Value::Uint32Value() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:2571): Use maybe version [-Wdeprecated-declarations]
                 obj->mqattrs.mq_msgsize = val->Uint32Value();
                                                            ^
../src/posixmq.cc: In static member function ‘static void PosixMQ::Send(const Nan::FunctionCallbackInfo<v8::Value>&)’:
../src/posixmq.cc:366:61: warning: ‘uint32_t v8::Value::Uint32Value() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:2571): Use maybe version [-Wdeprecated-declarations]
             if (info[1]->IsUint32() && info[1]->Uint32Value() < 32) {
                                                             ^
../src/posixmq.cc:367:49: warning: ‘uint32_t v8::Value::Uint32Value() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:2571): Use maybe version [-Wdeprecated-declarations]
                 priority = info[1]->Uint32Value();
                                                 ^
../src/posixmq.cc:377:85: warning: ‘v8::Local<v8::Object> v8::Value::ToObject() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:10254): Use maybe version [-Wdeprecated-declarations]
             send_result = mq_send(obj->mqueue, node::Buffer::Data(info[0]->ToObject()),
                                                                                     ^
../src/posixmq.cc:378:56: warning: ‘v8::Local<v8::Object> v8::Value::ToObject() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:10254): Use maybe version [-Wdeprecated-declarations]
                 node::Buffer::Length(info[0]->ToObject()), priority);
                                                        ^
../src/posixmq.cc: In static member function ‘static void PosixMQ::Receive(const Nan::FunctionCallbackInfo<v8::Value>&)’:
../src/posixmq.cc:424:46: warning: ‘bool v8::Value::BooleanValue() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:2568): Use maybe version [-Wdeprecated-declarations]
             retTuple = info[1]->BooleanValue();
                                              ^
../src/posixmq.cc:427:55: warning: ‘v8::Local<v8::Object> v8::Value::ToObject() const’ is deprecated (declared at /home/travis/.node-gyp/11.6.0/include/node/v8.h:10254): Use maybe version [-Wdeprecated-declarations]
         v8::Local<v8::Object> buf = info[0]->ToObject();
                                                       ^
  SOLINK_MODULE(target) Release/obj.target/posixmq.node
  COPY Release/posixmq.node
make: Leaving directory `/home/travis/build/mikeokner/posix-mq/build'
added 1 package from 8 contributors and audited 1 package in 2.912s
found 0 vulnerabilities
The command "npm install" exited with 0.
0.08s$ node test.js
Writing 100 ('d') to the queue...
Writing 98 ('b') to the queue...
Writing 56 ('8') to the queue...
Writing 40 ('(') to the queue...
Writing 62 ('>') to the queue...
Writing 108 ('l') to the queue...
Writing 41 (')') to the queue...
Writing 83 ('S') to the queue...
Writing 41 (')') to the queue...
Writing 125 ('}') to the queue...
Writing 70 ('F') to the queue...
(node:5840) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.
Received message (1 bytes): d
Messages left: 9
Received message (1 bytes): b
Messages left: 8
Received message (1 bytes): 8
Messages left: 7
Received message (1 bytes): (
Messages left: 6
Received message (1 bytes): >
Messages left: 5
Received message (1 bytes): l
Messages left: 4
Received message (1 bytes): )
Messages left: 3
Received message (1 bytes): S
Messages left: 2
Received message (1 bytes): )
Messages left: 1
Received message (1 bytes): }
Messages left: 0
The command "node test.js" exited with 0.

Hopefully possible to resolve while still maintaining full backwards compatibility. If not we can drop support for versions of Node that are no longer supported.

[PeterBurner]

posix-mq is not compatible to the current Node.js LTS v12.13.0 and needs to be updated!!

[mikeokner]

At @PeterBurner's beck & call, I resolved most of the deprecation warnings and got it building for Node v12 as well as prior versions, but it's now throwing a runtime error node: symbol lookup error: build/Release/posixmq.node: undefined symbol: mq_open only on >v12.

Could possibly be due to this change in Node? nodejs/node#29727

[mikeokner]

Rearranged library linking config in binding.gyp and it seems to be picking up librt appropriately for all versions of Node now.