On Wednesday, 30 May 2018 at 20:57:32 UTC, DigitalDesigns wrote:
Why is this a runtime issue? It is not as if the execution of static this are non-deterministic. The compiler and linker must order the calls in some way. Maybe this is what you mean by own object/linker? But even then, they would only have to be checked once so why check every time the exe is ran when once it is ran it must remain statically oriented for all future.
Because of separate compilation, the compiler can't do it. Because the generic linker doesn't do that sort of thing, the linker can't do it.
The first part is essentially intractable - e.g. module A's static this uses a global variable in module B that's set by module C. Module A may be compiled separately from module C, so the compiler can't see the dependency.
If the linker is to do it, the compiler needs to encode the information in the object file, and the linker must be made specially to support this. Maybe this could be put in some optional section in the object file, and linkers that don't support it would just ignore the information. If a non-compliant linker is used, the runtime needs to have a fallback, so even this won't get us entirely out of the woods. Only supporting special linkers comes with its own set of problems.
-- Simen
