custom node.js addon can be built but not able to include - c++

Question

I am writing a custom node.js addon by C++ mixed with C program.
The addon.cc consists of something like
#define BUILDING_NODE_EXTENSION
#include <node.h>
#include <node_buffer.h>
using namespace v8;
using namespace node;
/* other logic and function... */
Handle<Value> RunCallback(const Arguments& args) {
HandleScope scope;
Local<Value> buffer1 = args[0];
size_t size = Buffer::Length(buffer1->ToObject());
char* bufferdata = Buffer::Data(buffer1->ToObject());
/* some logic written in C style ... */
Local<Function> cb = Local<Function>::Cast(args[1]);
const unsigned argc = 1;
Local<Value> argv[argc] = { Local<Value>::New(String::New(outputdata, outputSize)) };
cb->Call(Context::GetCurrent()->Global(), argc, argv);
return scope.Close(Undefined());
}
void Init(Handle<Object> target) {
target->Set(String::NewSymbol("runCallback"), FunctionTemplate::New(RunCallback)->GetFunction());
}
NODE_MODULE(addon, Init)
It also includes other .cc files, so the wscript is like this:
srcdir = '.'
blddir = 'build'
VERSION = '0.0.1'
def set_options(opt):
opt.tool_options('compiler_cxx')
def configure(conf):
conf.check_tool('compiler_cxx')
conf.check_tool('node_addon')
def build(bld):
obj = bld.new_task_gen('cxx', 'shlib', 'node_addon')
obj.target = 'addon'
obj.source = ['addon.cc', 'otherFiles.cc']
When I run node-waf configure, it shows:
Checking for program g++ or c++ : /usr/bin/g++
Checking for program cpp : /usr/bin/cpp
Checking for program ar : /usr/bin/ar
Checking for program ranlib : /usr/bin/ranlib
Checking for g++ : ok
Checking for node path : not found
Checking for node prefix : ok /usr/local
'configure' finished successfully (0.169s)
When I run node-waf build, it shows:
Waf: Entering directory `/path/build'
[ 1/25] cxx: addon.cc -> build/Release/addon_1.o
... list of file ...
build/Release/list of file -> build/Release/addon.node
Waf: Leaving directory `/path/build'
'build' finished successfully (0.544s)
But when I try the following in node REPL, it shows:
var addon = require("./build/Release/addon");
Error: Unable to load shared library /path/build/Release/addon.node
at Object..node (module.js:472:11)
at Module.load (module.js:348:31)
at Function._load (module.js:308:12)
at Module.require (module.js:354:17)
at require (module.js:370:17)
at repl:1:13
at REPLServer.eval (repl.js:80:21)
at repl.js:190:20
at REPLServer.eval (repl.js:87:5)
at Interface.<anonymous> (repl.js:182:12)
It is very strange. I have checked that the file should match with the system architecture:
$ file build/Release/addon.node
build/Release/addon.node: Mach-O 64-bit bundle x86_64
$ file `which node`
/usr/local/bin/node: Mach-O 64-bit executable x86_64
By looking at nm, it shows the following:
nm ./build/Release/addon.node
0000000000011880 s GCC_except_table30
0000000000001160 t _Init
U __Unwind_Resume_or_Rethrow
U ___bzero
U ___gxx_personality_v0
0000000000013220 D _addon_module
U _free
0000000000013600 D _lsfmeanTbl
0000000000013420 D _memLfTbl
U _memcpy
U _memmove
U _puts
U _realloc
0000000000011950 s _ssqEn_win.2272
000000000001341c D _stMemLTbl
00000000000132e0 D _state_frgqTbl
00000000000132c0 D _state_sq3Tbl
U dyld_stub_binder
(... many are omitted ...)
What will be the possible reasons? Is that I cannot just combine C files with C++ files to compile? Should I remove all malloc/realloc/free? Or any other possible reasons?

Answer 1

Wrap the definition of Init() and the NODE_MODULE macro in extern "C" to avoid name C++ mangling of the exported symbols:
extern "C" {
void Init(Handle<Object> target) {
target->Set(String::NewSymbol("runCallback"), FunctionTemplate::New(RunCallback)->GetFunction());
}
NODE_MODULE(addon, Init)
}

Answer 2

By using node.js which version >= 0.7.6. the problem is solved. Also, it has a lot more debug message.