6 ms·

Write a target that greps the Makefile itself and extracts the targets.

caust1c 11y ago
Then write a parser to regenerate all the targets! It's a good thing make is turing complete. :-)
TheDong 11y ago
As shown in the post, targets are not always grep-able. The post's makefile contained the target "par-30" even though that string appears nowhere on the page or in the makefile. You need to write a full parser to discover all the targets.
- Hello71 11y ago
  $ make -pqrf <(curl https://gist.githubusercontent.com/jgrahamc/2cc6df7fd5cd61c4d93f/raw/parallel) | grep '^[^ ]*:' | cut -d : -f 1 par-% par-22 par-30 par-5 par-27 par-31 all FORCE /proc/self/fd/13 par-13 par-9 par-23 par-19 .SUFFIXES par-15 par-7 parallel par-29 par-28 .parallel par-4 par-25 par-6 par-14 .DEFAULT par-24 par-0 par par-1 par-10 par-16 par-2 par-11 par-17 par-20 par-8 par-21 par-12 par-26 par-18 par-3
  - TheDong 11y ago
    Right, you used 'make' as the parser. He said "grep the makefile". You're not grepping the makefile. Nice solution though!
    - Hello71 11y ago
      > You need to write a full parser to discover all the targets. I don't think grep '^[^ ]*:' really counts as writing a parser.
      - TheDong 11y ago
        Running "make -p" is running a full parser which someone else wrote. Grep is not extracting the targets from a makefile there, it's extracting the targets from an intermediate representation of a makefile.
        Hello71 11y ago
        > The real insanity with make is that it has no interface to check whether a Makefile contains a given target. > > Best you can do is to run make -n target to probe, but it's possible to write Makefiles that run code even though -n is used, which will defeat such probes at distribution scale. It quickly becomes an exercise in heuristics and output parsing.
        TheDong 11y ago
        We're arguing different things. The comment I replied to, chaosfactors, specifically specified grepping the makefile. You're arguing that you can find all the targets and I never said you can't. I simply said you can't find them all by only grepping the makefile.
oso2k 11y ago
I usually add two targets for my my projects: 'help' and 'showconfig'. 'make help' explains which targets to use and/or how to combine them. 'make showconfig' shows all the important what the important internal vars and common vars (CFLAGS, LDFLAGS, etc) are and their values.

Then write a parser to regenerate all the targets! It's a good thing make is turing complete. :-)

As shown in the post, targets are not always grep-able. The post's makefile contained the target "par-30" even though that string appears nowhere on the page or in the makefile. You need to write a full parser to discover all the targets.

Hello71 11y ago
$ make -pqrf <(curl https://gist.githubusercontent.com/jgrahamc/2cc6df7fd5cd61c4d93f/raw/parallel) | grep '^[^ ]*:' | cut -d : -f 1 par-% par-22 par-30 par-5 par-27 par-31 all FORCE /proc/self/fd/13 par-13 par-9 par-23 par-19 .SUFFIXES par-15 par-7 parallel par-29 par-28 .parallel par-4 par-25 par-6 par-14 .DEFAULT par-24 par-0 par par-1 par-10 par-16 par-2 par-11 par-17 par-20 par-8 par-21 par-12 par-26 par-18 par-3
- TheDong 11y ago
  Right, you used 'make' as the parser. He said "grep the makefile". You're not grepping the makefile. Nice solution though!
  - Hello71 11y ago
    > You need to write a full parser to discover all the targets. I don't think grep '^[^ ]*:' really counts as writing a parser.
    - TheDong 11y ago
      Running "make -p" is running a full parser which someone else wrote. Grep is not extracting the targets from a makefile there, it's extracting the targets from an intermediate representation of a makefile.
      - Hello71 11y ago
        > The real insanity with make is that it has no interface to check whether a Makefile contains a given target. > > Best you can do is to run make -n target to probe, but it's possible to write Makefiles that run code even though -n is used, which will defeat such probes at distribution scale. It quickly becomes an exercise in heuristics and output parsing.
        TheDong 11y ago
        We're arguing different things. The comment I replied to, chaosfactors, specifically specified grepping the makefile. You're arguing that you can find all the targets and I never said you can't. I simply said you can't find them all by only grepping the makefile.

oso2k 11y ago

I usually add two targets for my my projects: 'help' and 'showconfig'. 'make help' explains which targets to use and/or how to combine them. 'make showconfig' shows all the important what the important internal vars and common vars (CFLAGS, LDFLAGS, etc) are and their values.