[froh]

when does golang create the final dynamic dispatch tables? isn't that the one thing that in golang needs real compute at final link time, beyond what a C linker would do? and where C++ has all information at compile time, while golang can only create the dispatch tables at link time?

[jespino]

Yes, there is some information that is written by the linker in the final data section of the binary, the itab, that is the interface table for the dynamic dispatching. AFAIK, it is done there because you need to know other packages structs and interfaces to have the whole picture and build that table, and that happens using the build cache.

[froh]

yes, the interface tables! that was the word I didn't remember. and that is some computation going on there not "just" merging sections, and, in a normal static linker, wiring exports to imports, and not pulling in unneeded definitions (dead code elimination).

the interface table computation is a golang speciality, a fascinating one.

and the implementation of interface magic is disturbingly not mentioned in the article.