JSCAgent: add support for executing against jsc built from source.

lib/ConsoleAgent.js

@@ -11,14 +11,14 @@ class ConsoleAgent extends Agent {
   constructor(options) {
     super(options);
     this.printCommand = 'print';
-
+    this.cpOptions = {};
     // Promise for the child process created by the most recent invocation of
     // `evalScript`
     this._cp = null;
   }
 
-  createChildProcess(args = []) {
-    return cp.spawn(this.hostPath, this.args.concat(args));
+  createChildProcess(args = [], options = {}) {
+    return cp.spawn(this.hostPath, this.args.concat(args), options);
   }
 
   receiveOut(cp, str) {

lib/agents/jsc.js

@@ -1,12 +1,16 @@
 'use strict';
 
 const fs = require('fs');
+const path = require('path');
+const isSymlink = require('is-symlink');
 const inception = require('../inception');
 const runtimePath = require('../runtimePath');
 const ConsoleAgent = require('../ConsoleAgent');
 
 const errorRe = /(?:.*?): (\w+)(?:: (.*))?(?:\r?\nat[^\n]*)?(\r?\n.*@(\[native code\]|(?:.*:\d+:\d+)))*\r?\n/;
 
+let DYLD_FRAMEWORK_PATH = process.env.DYLD_FRAMEWORK_PATH;
+
 // JSC stack frame format:
 // StackFrames: StackFrame+
 // StackFrame: FunctionFrame | NativeFrame | EvalMarker
@@ -60,6 +64,56 @@ function parseStack(stackStr) {
 }
 
 class JSCAgent extends ConsoleAgent {
+  constructor(...args) {
+    super(...args);
+
+    /*
+      See: https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man1/dyld.1.html
+
+      This is frustrating, but necessary. DYLD_FRAMEWORK_PATH won't appear
+      in process.env when node.js scripts are executed as binaries,
+      ie. have a /usr/bin/env she-bang, because DYLD_* vars are excluded from env output
+
+      $ export DYLD_FRAMEWORK_PATH="foo"
+      $ node -pe process.env.DYLD_FRAMEWORK_PATH
+      foo
+      $ env | grep "DYLD_FRAMEWORK_PATH"
+      (not found, nothing prints)
+
+
+      Still not convinced? The following code shows that even WebKit's own run-jsc
+      script must do this dance to ensure that DYLD_FRAMEWORK_PATH is set with the
+      correct path for executing built-from-source jsc:
+
+      - https://github.com/WebKit/webkit/blob/026ee0438dd6c9cff16c27eb7ce9eaed2b43491c/Tools/Scripts/run-jsc#L58-L61
+      - https://github.com/WebKit/webkit/blob/026ee0438dd6c9cff16c27eb7ce9eaed2b43491c/Tools/Scripts/webkitdirs.pm#L786-L789
+      - https://github.com/WebKit/webkit/blob/026ee0438dd6c9cff16c27eb7ce9eaed2b43491c/Tools/Scripts/webkitdirs.pm#L770-L784
+    */
+
+    if (DYLD_FRAMEWORK_PATH === undefined) {
+      if (isSymlink.sync(this.hostPath)) {
+        let linked = fs.readlinkSync(this.hostPath);
+        if (linked.includes('WebKit/WebKitBuild')) {
+          DYLD_FRAMEWORK_PATH = path.dirname(linked);
+        }
+      } else {
+        if (this.hostPath.includes('WebKit/WebKitBuild')) {
+          DYLD_FRAMEWORK_PATH = path.dirname(this.hostPath);
+        }
+      }
+    }
+
+    this.cpOptions = {
+      env: {
+        DYLD_FRAMEWORK_PATH
+      }
+    };
+  }
+
+  createChildProcess(args = []) {
+    return super.createChildProcess(args, this.cpOptions);
+  }
+
   parseError(str) {
     const match = str.match(errorRe);
 

package.json

@@ -20,6 +20,7 @@
   },
   "dependencies": {
     "error-stack-parser": "^1.3.3",
+    "is-symlink": "^0.1.1",
     "selenium-webdriver": "^3.4.0",
     "server-destroy": "^1.0.1",
     "socket.io": "^1.3.7",