Sr173/hello_npm

electron-cpp-addon

This is a minimal repro to demonstrate an issue with building native addons for Electron that use standard C++ headers and libraries.

It's based on the simplest "hello_world" addon from node-addon-examples with a one-line change to include the C++11 standard include file <regex>.

Issue

What Happens:

On my system (A Mac running macOS Sierra 10.12.2) this addon compiles with no warnings or errors when using node-gyp to build for node.js v7.1.0.

Rebuilding this addon for electron.js following the instructions in Using Native Node Modules fails with an error indicating the the standard C++ header file <regex> is not found.

What I'd expect to happen:

I would expect this addon to compile without warnings or errors when building for electron.

Instructions to Reproduce the Issue

Clone This Repo and and Build for Node.js

$ git clone git@github.com:antonycourtney/electron-cpp-addon.git
[...]
$ cd electron-cpp-addon
$ npm install

The final command should produce output something like the following:

> hello_world@0.0.0 install /private/tmp/electron-cpp-addon
> node-gyp rebuild

  CXX(target) Release/obj.target/hello/hello.o
  SOLINK_MODULE(target) Release/hello.node
hello_world@0.0.0 /private/tmp/electron-cpp-addon
├── bindings@1.2.1
└── nan@2.5.0
$

Confirm that this built succesfully:

$ node --version
v7.1.0
$ node hello.js
world
$

( You can also run the commmand node-gyp rebuild manually from the shell any time after npm install to recompile the addon for node.)

Attempt to Build for Electron

Following the approach recommended in Using Native Node Modules, attempt to run node-gyp to rebuild this addon for Electron:

$ HOME=~/.electron-gyp node-gyp rebuild --target=1.4.15 --arch=x64

On my machine, this produces the following output:

gyp info it worked if it ends with ok
gyp info using node-gyp@3.5.0
gyp info using node@7.1.0 | darwin | x64
gyp info spawn /Users/antony/anaconda/bin/python2
gyp info spawn args [ '/usr/local/lib/node_modules/node-gyp/gyp/gyp_main.py',
gyp info spawn args   'binding.gyp',
gyp info spawn args   '-f',
gyp info spawn args   'make',
gyp info spawn args   '-I',
gyp info spawn args   '/private/tmp/electron-cpp-addon/build/config.gypi',
gyp info spawn args   '-I',
gyp info spawn args   '/usr/local/lib/node_modules/node-gyp/addon.gypi',
gyp info spawn args   '-I',
gyp info spawn args   '/Users/antony/.electron-gyp/.node-gyp/iojs-1.4.15/common.gypi',
gyp info spawn args   '-Dlibrary=shared_library',
gyp info spawn args   '-Dvisibility=default',
gyp info spawn args   '-Dnode_root_dir=/Users/antony/.electron-gyp/.node-gyp/iojs-1.4.15',
gyp info spawn args   '-Dnode_gyp_dir=/usr/local/lib/node_modules/node-gyp',
gyp info spawn args   '-Dnode_lib_file=iojs.lib',
gyp info spawn args   '-Dmodule_root_dir=/private/tmp/electron-cpp-addon',
gyp info spawn args   '--depth=.',
gyp info spawn args   '--no-parallel',
gyp info spawn args   '--generator-output',
gyp info spawn args   'build',
gyp info spawn args   '-Goutput_dir=.' ]
gyp info spawn make
gyp info spawn args [ 'BUILDTYPE=Release', '-C', 'build' ]
  CXX(target) Release/obj.target/hello/hello.o
../hello.cc:2:10: fatal error: 'regex' file not found
#include <regex>
         ^
1 error generated.
make: *** [Release/obj.target/hello/hello.o] Error 1
gyp ERR! build error
gyp ERR! stack Error: `make` failed with exit code: 2
gyp ERR! stack     at ChildProcess.onExit (/usr/local/lib/node_modules/node-gyp/lib/build.js:276:23)
gyp ERR! stack     at emitTwo (events.js:106:13)
gyp ERR! stack     at ChildProcess.emit (events.js:191:7)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:215:12)
gyp ERR! System Darwin 16.3.0
gyp ERR! command "/usr/local/bin/node" "/usr/local/bin/node-gyp" "rebuild" "--target=1.4.15" "--arch=x64"
gyp ERR! cwd /private/tmp/electron-cpp-addon
gyp ERR! node -v v7.1.0
gyp ERR! node-gyp -v v3.5.0
gyp ERR! not ok
$

Analysis and Workaround

If we run the node-gyp rebuild command manually to build for node.js, we see that the common.gypi file used by node-gyp when building for node (7.1.0 on my system) is ~/.node-gyp/7.1.0/include/node/common.gypi whereas when we build for electron, we are using ~/.electron-gyp/.node-gyp/iojs-1.4.14/common.gypi.

digging in to these two files and comparing the differences, we see that around line 387 in node's common.gypi we have:

['clang==1', {
  'xcode_settings': {
    'GCC_VERSION': 'com.apple.compilers.llvm.clang.1_0',
    'CLANG_CXX_LANGUAGE_STANDARD': 'gnu++0x',  # -std=gnu++0x
    'CLANG_CXX_LIBRARY': 'libc++',
  },
}],

The corresponding fragment from electron's version of the same file is almost identical, but missing the CLANG_CXX_LIBRARY definition:

['clang==1', {
  'xcode_settings': {
    'GCC_VERSION': 'com.apple.compilers.llvm.clang.1_0',
    'CLANG_CXX_LANGUAGE_STANDARD': 'gnu++0x',  # -std=gnu++0x
  },
}],

Workaround

We can get this to compile if we add the following fragment to binding.gyp in this project:

"conditions": [
  [ 'OS=="mac"', {
    'xcode_settings': {
      'CLANG_CXX_LIBRARY': 'libc++'
    }
}]]

This should be added as a property of the object in the targets array, so that the complete binding.gyp becomes:

{
  "targets": [
    {
      "target_name": "hello",
      "sources": [ "hello.cc" ],
      "include_dirs": [
        "<!(node -e \"require('nan')\")"
      ],
      "conditions": [
        [ 'OS=="mac"', {
          'xcode_settings': {
            'CLANG_CXX_LIBRARY': 'libc++'
          }
      }]]
    }
  ]
}