How do you get the list of targets in a makefile?


Answers

Under Bash (at least), this can be done automatically with tab completion:

make(space)(tab)(tab)
Question

I've used rake a bit (a Ruby make program), and it has an option to get a list of all the available targets, eg

> rake --tasks
rake db:charset      # retrieve the charset for your data...
rake db:collation    # retrieve the collation for your da...
rake db:create       # Creates the databases defined in y...
rake db:drop         # Drops the database for your curren...
...

but there seems to be no option to do this in GNU make.

Apparently the code is almost there for it, as of 2007 - http://www.mail-archive.com/help-make@gnu.org/msg06434.html.

Anyway, I made little hack to extract the targets from a makefile, which you can include in a makefile.

list:
    @grep '^[^#[:space:]].*:' Makefile

It will give you a list of the defined targets. It's just a start - it doesn't filter out the dependencies, for instance.

> make list
list:
copy:
run:
plot:
turnin:



This one was helpful to me because I wanted to see the build targets required (and their dependencies) by the make target. I know that make targets cannot begin with a "." character. I don't know what languages are supported, so I went with egrep's bracket expressions.

cat Makefile | egrep "^[[:alnum:][:punct:]]{0,}:[[:space:]]{0,}[[:alnum:][:punct:][:space:]]{0,}$"



@nobar's answer helpfully shows how to use tab completion to list a makefile's targets.

  • This works great for platforms that provide this functionality by default (e.g., Debian, Fedora).

  • On other platforms (e.g., Ubuntu) you must explicitly load this functionality, as implied by @hek2mgl's answer:

    • . /etc/bash_completion installs several tab-completion functions, including the one for make
    • Alternatively, to install only tab completion for make:
      • . /usr/share/bash-completion/completions/make
  • For platforms that don't offer this functionality at all, such as OSX, you can source the following commands (adapated from here) to implement it:
_complete_make() { COMPREPLY=($(compgen -W "$(make -pRrq : 2>/dev/null | awk -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($1 !~ "^[#.]") {print $1}}' | egrep -v '^[^[:alnum:]]' | sort | xargs)" -- "${COMP_WORDS[$COMP_CWORD]}")); }
complete -F _complete_make make
  • Note: This is not as sophisticated as the tab-completion functionality that comes with Linux distributions: most notably, it invariably targets the makefile in the current directory, even if the command line targets a different makefile with -f <file>.



Plenty of workable solutions here, but as I like saying, "if it's worth doing once, it's worth doing again." I did upvote the sugestion to use (tab)(tab), but as some have noted, you may not have completion support, or, if you have many include files, you may want an easier way to know where a target is defined.

I have not tested the below with sub-makes...I think it wouldn't work. As we know, recursive makes considered harmful.

.PHONY: list ls
ls list :
    @# search all include files for targets.
    @# ... excluding special targets, and output dynamic rule definitions unresolved.
    @for inc in $(MAKEFILE_LIST); do \
    echo ' =' $$inc '= '; \
    grep -Eo '^[^\.#[:blank:]]+.*:.*' $$inc | grep -v ':=' | \
    cut -f 1 | sort | sed 's/.*/  &/' | sed -n 's/:.*$$//p' | \
    tr $$ \\\ | tr $(open_paren) % | tr $(close_paren) % \
; done

# to get around escaping limitations:
open_paren := \(
close_paren := \)

Which I like because:

  • list targets by include file.
  • output raw dynamic target definitions (replaces variable delimiters with modulo)
  • output each target on a new line
  • seems clearer (subjective opinion)

Explanation:

  • foreach file in the MAKEFILE_LIST
  • output the name of the file
  • grep lines containing a colon, that are not indented, not comments, and don't start with a period
  • exclude immediate assignment expressions (:=)
  • cut, sort, indent, and chop rule-dependencies (after colon)
  • munge variable delimiters to prevent expansion

Sample Output:

 = Makefile = 
  includes
  ls list
 = util/kiss/snapshots.mk = 
  rotate-db-snapshots
  rotate-file-snapshots
  snap-db
  snap-files
  snapshot
 = util/kiss/main.mk = 
  dirs
  install
   %MK_DIR_PREFIX%env-config.php
   %MK_DIR_PREFIX%../srdb



If you have bash completion for make installed, the completion script will define a function _make_target_extract_script. This function is meant to create a sed script which can be used to obtain the targets as a list.

Use it like this:

# Make sure bash completion is enabled
source /etc/bash_completion 

# List targets from Makefile
sed -nrf <(_make_target_extract_script --) Makefile



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