What is the difference between binary and source compatibility conceptually ?

Question

In the context of webkit in chromium source code ,it says it is source compatible but not binary compatible. Does it suggest that we build .dll file of webkit and build it with chrome binary ?

Answer 1

(This answer doesn't talk about the specific context of WebKit - it's not clear what exactly you mean by the various "it says" parts. I've tried to give a more general answer.)

Suppose we have a library called LibFoo, and you have built an application called SuperBar which uses LibFoo v1.

Now LibFoo v1.1 comes out.

• If this is binary compatible, then you should be able to just drop in the new binary, and SuperBar will work using the new code without any other changes
• If this is only source compatible then you need to rebuild SuperBar against v1.1 before you'll be able to use it

Answer 2

I would think of it from the point of view of Linking

Linking is the process of taking a class or interface and combining it into the run-time state of the Java Virtual Machine so that it can be executed.

Linking a class or interface involves verifying and preparing that class or interface, its direct superclass, its direct superinterfaces, and its element type (if it is an array type), if necessary.

If introducing a new change breaks the linking, then it is not source (code) compatible (as well as binary compatible)

If introducing a new change does not break the linking, then it is at least binary compatible