Felipe Contreras <felipe.contre...@gmail.com> writes: >> - There may be pieces of usefully reusable code buried in >> builtin/*.o; >> >> - By definition, any code (piece of data or function definition) in >> builtin/*.o cannot be used in standalone binaries, because all of >> builtin/*.o expect to link with git.o and expect their cmd_foo() >> getting called from main in it; >> >> - By moving the useful reusable pieces ont of builtin/*.o and >> adding them to libgit.a, these pieces become usable from >> standalone binaries as well. > > What if these reusable pieces should not be used by standalone binaries?
I am not sure what you mean. A piece is either reusable or not. When would one piece _be_ reusable and should *not* be used in one context but not in another? There are distinctions between being "useful" and "usable", but I think the zeroth order of approximation when thinking about this is to think builtin/*.o as set of subroutines called by git.c::main(). These set of subroutines may call out to more generic helper functions that are usable from anywhere both within builtins and also from standalone. They may also call to their own helper functions that were originally designed to support only their use by the original caller from somewhere in builtin/*.o (most commonly in the same file, marked as static). The general direction, if we want to have an improve libgit.a, should be to see if the functions and their data that are private to builtin/*.o can be used from standalone, either as they are or with more generalization, and turn them from helpers specific to one cmd_foo() into more generally useful library-ish functions. There may be pieces in the callchain from that entry point to cmd_foo() that are implementation details of git.c::main(); for example the loop that does command dispatching to check with builtins, external commands that begin with git-, and aliases, is one of them, and would not be usable (nor it is useful) outside the context of "git" aggregate binary. But there are things that ought to be usable that are currently in builtin/*.o, which prevents them from being used by standalone binaries. If a remote helper binary that is standalone wants to call "create_note()", it is not sufficient to make it non-static in builtin/notes.o, for example. But if it is moved outside builtin/notes.o, it becomes usable. I think the "git notes", being one of the most recent additions, haven't gone through enough round of refactoring to come to the best separation between library-ish part (i.e. could be in notes.o, even though it is mostly about the underlying data structure manipulation and contains no higher-level operations like actually creating and copying, which might want to be in a separate source notes-lib.o) and its CLI implementation "builtin/notes.o". > But this doesn't answer the question; what about code that is shared > between builtins, but cannot be used by standalone programs? Again, I do not know what you mean by "cannot" here. My tentative answer to that question is "the eventual goal should be not to have any code in that class, and that is a reasonable goal we can achieve once we refactor what ought to be reusable out of builtin/*.o". What are the examples you have in mind, code that we want to forbid standalone from using? -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
