Read version using subprocesses

solc-js or emscripten causes some kind of memory leak and node.js runs out of memory

Author: axic

package.json

@@ -8,7 +8,6 @@
   },
   "devDependencies": {
     "ethereumjs-util": "^5.0.1",
-    "solc": "^0.4.24",
     "standard": "^8.4.0",
     "swarmhash": "^0.1.0"
   },

update

@@ -7,7 +7,7 @@ const path = require('path')
 const semver = require('semver')
 const ethUtil = require('ethereumjs-util')
 const swarmhash = require('swarmhash')
-const solc = require('solc/wrapper')
+const cp = require('child_process')
 
 // This script updates the index files list.js and list.txt in the bin directory,
 // as well as the soljson-latest.js files.
@@ -33,7 +33,10 @@ fs.readdir(path.join(__dirname, '/bin'), function (err, files) {
   }
 
   function readBuiltinVersion (file) {
-    return solc(require(path.join(__dirname, '/bin', file))).version()
+    // NOTE: should be using this, but it leaks memory
+    // return solc(require(path.join(__dirname, '/bin', file))).version()
+    const filename = path.join(__dirname, '/bin', file)
+    return cp.execSync(`/usr/bin/env node -e "console.log(require('${filename}').cwrap('version', 'string', [])())"`).toString().trim()
   }
 
   // ascending list (oldest version first)