On December 1, 2021 9:06 AM, Tim Murphy wrote: > On Wed, 1 Dec 2021 at 12:37, Edward Welbourne <mailto:edward.welbou...@qt.io> > wrote: >> mailto:rsbec...@nexbridge.com (1 December 2021 13:08) wrote: >>> I would suggest that adding cryptography to GNU Make would limit its >>> reach. There are jurisdictions where it is questionable to import >>> software containing any cryptography. In addition, there are numerous >>> tools for doing what you want. Something along the lines, for example, >>> of: >>> >>> $(shell git hash-object obj) >>> >>> Is a simple function that is already supported by GNU Make without >>> having to introduce cryptography. This would make a lot more sense to >> me to keep hashing out of GNU Make.
>> +1. It also leaves it to the make file author to decide which hash >> function to use. If make took charge of that decision, it would be >> stuck with the hash selected for all time, since it would have no way of >> knowing how the resulting hashes have been used by diverse different >> make files. An individual project's make files can make the transition >> from using one hash to another, since it knows how it's been using the >> hashes and how to ensure a clean transition when it comes to change the >> hash function used. > I have added such a function as a loadable library before - you might > consider that if you can't get it done another way. > https://github.com/tnmurphy/extramake > > look at hash.c. To try it : > > cd example && make -f http://example.mk > > I called the function siphash24 because that's what I used - and its' > definitely not cryptographic. I had similar needs such as generating unique > target names from many inputs > where I didn't want the target name to be of unlimited length or to have > illegal characters. > > $(shell) was useless as it is far too slow. > > I would suggest having $(hash) and $(<hash-alg>) - because then people who > care about the algorithm will be able to choose it. > > > FYI loadable modules are quite cool: > SOURCES:=proga.c progb.c > OBJECTS:=$(SOURCES:.c=.o) > > > include ../http://xtra.mk > XTRA_OUTPUTDIR:=. > XTRA_SOURCE:=.. > -load $(XTRA_OUTPUTDIR)/hash$(XTRA_EXT) > > LIBVERSION:=$(siphash24 $(SOURCES)) > LIBNAME:=prog_$(LIBVERSION).so > $(LIBNAME): $(OBJECTS) > cc -o $@ $^ -shared > > $(OBJECTS) : %.o : %.c > cc -c -o $@ -fPIC $^ > include ../http://hash.mk > > The above will build the $(siphash24) function (if it's not there already) > and then use it. I am fine with using loadable modules to add functionality to GNU Make. I will probably contribute a change here so that it works on other platform(s) at some point. I also get that $(shell) can be very slow on some platforms. Randall
