Upgrading to Spidermonkey 1.8

Spidermonkey is a C library for executing Javascript from inside of your application.  Although fast an reliable, new versions tend to break compatibility.  I just updated my computer from 1.7 to 1.8.5.  During that upgrade, here are a few of the problems that I faced:

1) JS_GetStringBytes() has been retired

JS_GetStringBytes() returned a pointer to the private character array of the JSString.  I can understand why the API designers wouldn't want to give out a pointer to private data.  It has been replaced by JS_EncodeString() which requires a corresponding JS_free() call.

2) JS_AddRoot() and JS_RemoveRoot() have been retired

Instead of a single generic function, there are now specific functions for each scenario.  All of my JS_AddRoot() calls got turned to JS_AddObjectRoot() calls.

3) When defining a class, the SET method was changed from type JS_PropertyStub to JS_StrictPropertyStub

This required changing my definitions to JS_StrictPropertyStub or updaring my SET function to the new arguments.

4) Function pointers are now of type JSNative

This required a bunch of casts.  Before, I could pass in the function pointer.  Now, the DefineFunction function requires the pointer to be of type JSNative.  A Simple change.


After making all of those changes, my program compiles, but it doesn't run.  It SEGFAULTs on JS_NewObject().  I tried different variations of the call.  I recompiled Spidermonkey in debug mode but I don't get any more info.  I still get the following stack trace in GDB:

#0  0x00007ffff617eedc in ?? () from /usr/lib64/libmozjs185.so.1.0
#1  0x00007ffff617b0dd in JS_NewObject () from /usr/lib64/libmozjs185.so.1.0

I have decided to revert back to version 1.7.0 for now.  This in itself is problematic since I upgraded everything on the system, not just Spidermonkey.  Policykit requires 1.8.5, so I have to uninstall policykit.  A bunch of apps used policykit, so I had to recompile without policykit support (yay Gentoo).  I revered my svn commit and I was up and running.  I make a branch out of the 1.8.5 changes to see what I can do to get it to run in the future.