From c98de2173e95a1066ed37b16f3932bf11f880848 Mon Sep 17 00:00:00 2001 From: Andrea Bolognani Date: Tue, 2 Apr 2019 12:32:11 +0200 Subject: [PATCH] m4: readline: Use pkg-config where possible MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With the 7.0 release, readline has finally started shipping pkg-config support in the form of a readline.pc file. Unfortunately, most downstreams have yet to catch up with this change: among Linux distributions in particular, Fedora Rawhide seems to be the only one installing it at the moment. Non-Linux operating systems have been faring much better in this regard: both FreeBSD (through ports) and macOS (through homebrew) include pkg-config support in their readline package. This is great news for us, since those are the platforms where pkg-config is more useful on account of them installing headers and libraries outside of the respective default search paths. Our implementation checks whether readline is registered as a pkg-config package, and if so obtains CFLAGS and LIBS using the tool; if not, we just keep using the existing logic. This commit is best viewed with 'git show -w'. Signed-off-by: Andrea Bolognani Reviewed-by: Daniel P. Berrangé --- m4/virt-readline.m4 | 45 +++++++++++++++++++++++++++------------------ 1 file changed, 27 insertions(+), 18 deletions(-) diff --git a/m4/virt-readline.m4 b/m4/virt-readline.m4 index 6f0090056a..1bec5deb22 100644 --- a/m4/virt-readline.m4 +++ b/m4/virt-readline.m4 @@ -23,27 +23,36 @@ AC_DEFUN([LIBVIRT_ARG_READLINE],[ AC_DEFUN([LIBVIRT_CHECK_READLINE],[ - # This function is present in all reasonable (5.0+) readline versions; - # however, the macOS base system contains a library called libedit which - # takes over the readline name despite lacking many of its features. We - # want to make sure we only enable readline support when linking against - # the actual readline library, and the availability of this specific - # functions is as good a witness for that fact as any. - AC_CHECK_DECLS([rl_completion_quote_character], - [], [], - [[#include - #include ]]) + # We have to check for readline.pc's presence beforehand because for + # the longest time the library didn't ship a .pc file at all + PKG_CHECK_EXISTS([readline], [use_pkgconfig=1], [use_pkgconfig=0]) - if test "$ac_cv_have_decl_rl_completion_quote_character" = "no" ; then - if test "$with_readline" = "yes" ; then - AC_MSG_ERROR([readline is missing rl_completion_quote_character]) - else - with_readline=no; + if test $use_pkgconfig = 1; then + # readline 7.0 is the first version which includes pkg-config support + LIBVIRT_CHECK_PKG([READLINE], [readline], [7.0]) + else + # This function is present in all reasonable (5.0+) readline versions; + # however, the macOS base system contains a library called libedit which + # takes over the readline name despite lacking many of its features. We + # want to make sure we only enable readline support when linking against + # the actual readline library, and the availability of this specific + # functions is as good a witness for that fact as any. + AC_CHECK_DECLS([rl_completion_quote_character], + [], [], + [[#include + #include ]]) + + if test "$ac_cv_have_decl_rl_completion_quote_character" = "no" ; then + if test "$with_readline" = "yes" ; then + AC_MSG_ERROR([readline is missing rl_completion_quote_character]) + else + with_readline=no; + fi fi - fi - # The normal library check... - LIBVIRT_CHECK_LIB([READLINE], [readline], [readline], [readline/readline.h]) + # The normal library check... + LIBVIRT_CHECK_LIB([READLINE], [readline], [readline], [readline/readline.h]) + fi # We need this to avoid compilation issues with modern compilers. # See 9ea3424a178 for a more detailed explanation