PKG.M4(7)

✨ NAME ✨

okay so the name of this page is pkg.m4, and it's giving autoconf macros for using pkgconf 💖

🎀 SYNOPSIS 🎀

PKG_PREREQ
PKG_PROG_PKG_CONFIG
PKG_CHECK_MODULES
PKG_CHECK_MODULES_STATIC
PKG_INSTALLDIR
PKG_NOARCH_INSTALLDIR
PKG_CHECK_VAR
PKG_WITH_MODULES
PKG_HAVE_WITH_MODULES
PKG_HAVE_DEFINE_WITH_MODULES

🦋 DESCRIPTION 🦋

bestie, pkg.m4 is a whole collection of autoconf macros that help you set up compiler and linker flags for development libraries 🔥 Your build system can detect other dependencies and then use them with the system toolchain. literally so useful, no cap.

💅 AUTOCONF MACROS 💅

🌸 PKG_PREREQ(MIN-VERSION)

this one checks that the version of the pkg.m4 autoconf macros you're using is at least MIN-VERSION 🫶 It's how you make sure a particular pkg.m4 macro is actually going to be there when you need it.

✨ PKG_PROG_PKG_CONFIG([MIN-VERSION])

checks for an implementation of pkg-config that's at least MIN-VERSION or newer 💜

🧚 PKG_CHECK_MODULES(VARIABLE-PREFIX, MODULES [,ACTION-IF-FOUND [,ACTION-IF-NOT-FOUND]])

🧚 PKG_CHECK_MODULES_STATIC(VARIABLE-PREFIX, MODULES [,ACTION-IF-FOUND [,ACTION-IF-NOT-FOUND]])

this is the iconic one 👑 It checks whether a given module set exists, and if it does, it defines CFLAGS and LIBS variables prefixed by VARIABLE-PREFIX, filled with the output from --cflags and --libs respectively.

the optional ACTION-IF-FOUND and ACTION-IF-NOT-FOUND arguments are shell fragments that get executed if the module set is found or not found 🍓

if $PKG_CONFIG isn't defined, the PKG_PROG_PKG_CONFIG macro will run to go find a pkg-config implementation 🔍

and PKG_CHECK_MODULES_STATIC gives you the same behaviour as PKG_CHECK_MODULES, except with static linking turned on via the --static flag 🌈

🎀 PKG_INSTALLDIR(DIRECTORY)

this one defines the variable $pkgconfigdir as the spot where a package should install its pkg-config .pc files 📦

by default that directory is $libdir/pkgconfig, but you can change the default by passing in the DIRECTORY parameter 🛠️

and if you want to override it, use the --with-pkgconfigdir configure parameter 💖

🎀 PKG_NOARCH_INSTALLDIR(DIRECTORY)

this one defines the variable $noarch_pkgconfigdir as the spot where a package should install its pkg-config .pc files, but for the architecture-independent stuff 🦋

by default that directory is $datadir/pkgconfig, but again, you can change it by passing in the DIRECTORY parameter 🌸

to override it, use the --with-noarch-pkgconfigdir configure parameter ✨

🔮 PKG_CHECK_VAR(VARIABLE, MODULE, CONFIG-VARIABLE, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])

this one grabs the value of the pkg-config variable CONFIG-VARIABLE from MODULE and stores it in the VARIABLE variable 🧠

heads up: using VARIABLE more than once is not recommended! The check gets skipped if the variable is already set, so don't be surprised when your second call does nothing 🙈

🌈 PKG_WITH_MODULES(VARIABLE-PREFIX, MODULES, [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND], [DESCRIPTION], [DEFAULT])

this one sets up a "--with-" configure option using the lowercase VARIABLE-PREFIX name 🎨 It merges the behaviour of AC_ARG_WITH and PKG_CHECK_MODULES into one single macro, so you get two-in-one energy 💅

🌙 PKG_HAVE_WITH_MODULES(VARIABLE-PREFIX, MODULES, [DESCRIPTION], [DEFAULT])

a cute little convenience macro that triggers AM_CONDITIONAL after a PKG_WITH_MODULES check 🫶 VARIABLE-PREFIX gets exported as a make variable.

💜 PKG_HAVE_DEFINE_WITH_MODULES(VARIABLE-PREFIX, MODULES, [DESCRIPTION], [DEFAULT])

same vibe as above, but this one triggers both AM_CONDITIONAL and AC_DEFINE after a PKG_WITH_MODULES check 🔥 And yep, VARIABLE-PREFIX gets exported as a make variable too.

bestie, that's the whole page 💖 Brought to you by Debian, last updated December 5, 2017, filed under PKG.M4(7) 🌈✨ slay the autoconf! 💅🦋