On Wed, Jan 10, 2024 at 5:46 PM Paul Smith <psm...@gnu.org> wrote: > > On Wed, 2024-01-10 at 17:20 -0500, Dmitry Goncharov wrote: > > Investigating why I discovered the issue was as I mentioned below; once > we have set the flag for -e (the env_overrides global variable) there's > no way to unset it.
> What I was thinking was that the handling of MAKEFLAGS would be changed > so that the content of the MAKEFLAGS variable would be considered the > source of truth, and the values of the global variables set by the > command_switch array etc. would only be convenient shortcuts for that > information. > > In particular, every time MAKEFLAGS is changed we would first _reset_ > all the global variables back to their default values effectively > undoing whatever settings were made by the previous value of MAKEFLAGS, > then we would re-parse MAKEFLAGS from scratch and set whatever values > were there. > > By doing this we would ensure that, for example, if you have: > > MAKEFLAGS += -e > > MAKEFLAGS := $(subst e,,$(word 1,$(MAKEFLAGS))) \ > $(wordlist 2,$(words $(MAKEFLAGS),$(MAKEFLAGS)) > > then after the first MAKEFLAGS assignment we'd reset the global option > variables to their default (env_override = 0), then parse MAKEFLAGS > which sets env_override = 1. > Then after the second MAKEFLAGS assignment we'd reset the global option > variables to their default so env_override = 0, then after we parse > MAKEFLAGS the "e" option is not set anymore and env_override is left 0. You are designing a new feature, aren't you? Specifically, the ability to unset -e. If really needed, a makefile can reset -e on the command line for submake and have submake do the work. Alternatively, it is possible to introduce the opposite switch, just like -S and -k. > After all that, we can go through the variables and reset the override > status o_override vs. o_env_override if the value changed. Or, maybe > there's a better way to handle that; maybe for example we should > consider chaining variable sets like we do for target-specific > variables and inheritance, and keeping environment variables in a > different set and swapping the order of "env" vs "make" variable sets. > But this might be complicated, there are some special cases for > handling the global set. i agree that the makeflags business is overly complex. i feel, the main issue is that makeflags serves two functions, it carries command line switches to submake and it allows a makefile to set switches. This ability to set switches is the cause of the complexity. Instead of MAKEFLAGS+=-R i'd rather introduce a function like $(toggle_switch R, 1) # Set -R. $(toggle_switch R, 0) # Reset -R. However, this ship sailed 30 years ago. > Since I actually consider -e to be a terrible feature and would never > consider using it myself, maybe it's better to do the stupid, simple > thing and just go through all the variables and reset them :) i like this better, as long as the behavior matches the manual. regards, Dmitry
