[polari] build: Add configuration summary

[Florian Müllner <fmuellner src gnome org>]

commit 942f8b273958d4db77986cc292eb605692c0fbc2
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Mar 5 15:04:39 2020 +0100

    build: Add configuration summary
    
    Meson now has a summary() function to easily summarize the build
    configuration after the project was configured, use that for some
    fancy output when the feature is available.
    
    https://gitlab.gnome.org/GNOME/polari/-/merge_requests/148

 meson.build | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
---
diff --git a/meson.build b/meson.build
index 10c2b47..d0491f0 100644
--- a/meson.build
+++ b/meson.build
@@ -68,3 +68,21 @@ subdir('po')
 subdir('help')
 
 meson.add_install_script('meson/meson-postinstall.sh')
+
+summary_dirs = {
+  'prefix': get_option('prefix'),
+  'bindir': get_option('bindir'),
+  'libdir': get_option('libdir'),
+  'datadir': get_option('datadir'),
+}
+
+summary_build = {
+  'buildtype': get_option('buildtype'),
+  'snapshot': get_option('snapshot'),
+  'debug': get_option('debug'),
+}
+
+if meson.version().version_compare('>= 0.53.0')
+  summary(summary_dirs, section: 'Directories')
+  summary(summary_build, section: 'Build Configuration')
+endif