Add target_modules_version variable into generated config.gypi file

lib/configure.js

@@ -1,6 +1,7 @@
 module.exports = exports = configure
 module.exports.test = { findAccessibleSync: findAccessibleSync, 
-  findPython: findPython }
+  findPython: findPython,
+  nodeModulesVersion: nodeModulesVersion }
 
 /**
  * Module dependencies.
@@ -127,6 +128,15 @@ function configure (gyp, argv, callback) {
 
     // set the target_arch variable
     variables.target_arch = gyp.opts.arch || process.arch || 'ia32'
+    log.verbose('build/' + configFilename, 'target arch: ' + variables.target_arch)
+
+    // set the target_platform variable
+    variables.target_platform = process.platform
+    log.verbose('build/' + configFilename, 'target platform: ' + variables.target_platform)
+
+    // set the target modules version
+    variables.target_modules_version = nodeModulesVersion(nodeDir)
+    log.verbose('build/' + configFilename, 'modules version: ' + variables.target_modules_version)
 
     // set the node development directory
     variables.nodedir = nodeDir
@@ -311,6 +321,42 @@ function configure (gyp, argv, callback) {
 
 }
 
+/**
+ * Returns value of NODE_MODULE_VERSION define
+ * from Node source code in specified directory
+ * for specified Node version
+ */
+function nodeModulesVersion(nodeDir) {
+  var versionStr = path.basename(nodeDir)
+
+  // parse version from the base name of nodeDir
+  // probably removing optional `releaseName-` prefix
+  var nodeVersion = semver.valid(versionStr)
+                 || semver.valid(versionStr.substr(versionStr.indexOf('-') + 1))
+
+  if (!nodeVersion) {
+    throw new Error('Can\'t extract target version from ' + nodeDir)
+  }
+
+  // NODE_MODULE_VERSION may be defined in different files
+  // depending on the target Node.js version
+  if (semver.gte(nodeVersion, '3.0.0')) {
+    nodeVersion = 'include/node/node_version.h'
+  } else if (semver.gt(nodeVersion, '0.11.4')) {
+    nodeVersion = 'src/node_version.h'
+  } else {
+    nodeVersion = 'src/node.h'
+  }
+  nodeVersion = path.join(nodeDir, nodeVersion)
+
+  var modulesVersion = fs.readFileSync(nodeVersion, { encoding: 'utf8'})
+                          .match(/#define\s+NODE_MODULE_VERSION\s+\(?(\S+)\)?/)
+  if (!modulesVersion) {
+    throw new Error('#define NODE_MODULE_VERSION not found in ' + nodeVersion)
+  }
+  return parseInt(modulesVersion[1]).toString()
+}
+
 /**
  * Returns the first file or directory from an array of candidates that is 
  * readable by the current user, or undefined if none of the candidates are

test/test-node-modules-version.js

@@ -0,0 +1,34 @@
+'use strict'
+
+var test = require('tape')
+var path = require('path')
+var semver = require('semver')
+var processRelease = require('../lib/process-release')
+var configure = require('../lib/configure')
+
+var gyp = require('../lib/node-gyp')() // for gyp.devDir
+gyp.parseArgv([]) // to initialize gyp.opts
+
+test('modules version for the current release', function (t) {
+  t.plan(1)
+
+  var release = processRelease([], gyp, process.version)
+  var nodeDir = path.join(gyp.devDir, release.versionDir)
+  var modulesVersion = configure.test.nodeModulesVersion(nodeDir)
+  t.equal(modulesVersion, process.versions.modules,
+    nodeDir + ' modulesVersion=' + modulesVersion)
+})
+
+test('node modules version for installed targets', function (t) {
+  gyp.commands.list([], function(err, versions) {
+    if (err) return t.fail(err)
+    t.plan(versions.length)
+
+    versions.forEach(function(version) {
+      var nodeDir = path.join(gyp.devDir, version)
+      var modulesVersion = configure.test.nodeModulesVersion(nodeDir)
+      t.ok(modulesVersion > 0,
+        nodeDir + ' modulesVersion=' + modulesVersion)
+    })
+  })
+})