"Single item in a set depends on the whole set. Set depends on that item."
I'm creating a compiler (https://github.com/SuperJMN/Plotty). In the last stage, the Intermediate Code is converted to Machine Instructions. I have them represented with the
To do it, I'm using the Visitor Pattern, that visits each of the elements of the list of Intermediate Codes. Each Intermediate Code can emit one or more MachineCodes.
It's working perfectly, but I have a big problem: one of the instructions that must be generated is dependent on the whole result! Concretely, there is an instruction that needs to know the index (ordinal) of another instruction has not been generated yet.
In other words, I have to emit an instruction that means "push the address of
label X", when
label X hasn't been emitted yet. The address of that label will only be known when all the instructions have been emitted.
The illustrate the problem better, this is similar to the creation of table of contents in a document. If you want to be able to create the TOC, where you want to specify the page number of a given section, first you have to generate the all the document, so you can then know the page of a given section.
Can you please tell me an algoritmo or a pattern to solve my problem? I don't know how to emit those pending-fix instructions.