build: Add Build API wrapper for meson/ninja

The Build API[0] used by gnome-continuous expects a configure
script that generates a Makefile, so grab a copy of graphene's
compatibility script[1] to make it happy.

[0] https://github.com/cgwalters/build-api
[1] https://github.com/ebassi/graphene/blob/master/configure

https://bugzilla.gnome.org/show_bug.cgi?id=785153

configure

@@ -0,0 +1,159 @@
+#!/bin/bash
+# configure script adapter for Meson
+# Based on build-api: https://github.com/cgwalters/build-api
+# Copyright 2010, 2011, 2013 Colin Walters <walters@verbum.org>
+# Copyright 2016, 2017 Emmanuele Bassi
+# Licensed under the new-BSD license (http://www.opensource.org/licenses/bsd-license.php)
+
+# Build API variables:
+
+# Little helper function for reading args from the commandline.
+# it automatically handles -a b and -a=b variants, and returns 1 if
+# we need to shift $3.
+read_arg() {
+    # $1 = arg name
+    # $2 = arg value
+    # $3 = arg parameter
+    local rematch='^[^=]*=(.*)$'
+    if [[ $2 =~ $rematch ]]; then
+	read "$1" <<< "${BASH_REMATCH[1]}"
+    else
+	read "$1" <<< "$3"
+	# There is no way to shift our callers args, so
+	# return 1 to indicate they should do it instead.
+	return 1
+    fi
+}
+
+sanitycheck() {
+    # $1 = arg name
+    # $1 = arg command
+    # $2 = arg alternates
+    local cmd=$( which $2 2>/dev/null )
+
+    if [ -x "$cmd" ]; then
+        read "$1" <<< "$cmd"
+        return 0
+    fi
+
+    test -z $3 || {
+        for alt in $3; do
+            cmd=$( which $alt 2>/dev/null )
+
+            if [ -x "$cmd" ]; then
+                read "$1" <<< "$cmd"
+                return 0
+            fi
+        done
+    }
+
+    echo -e "\e[1;31mERROR\e[0m: Command '$2' not found"
+    exit 1
+}
+
+sanitycheck MESON 'meson'
+sanitycheck MESONTEST 'mesontest'
+sanitycheck NINJA 'ninja' 'ninja-build'
+
+enable_docs='-Denable-gtk-doc=false'
+enable_man='-Denable-man=false'
+enable_introspection=''
+
+while (($# > 0)); do
+    case "${1%%=*}" in
+	--prefix) read_arg prefix "$@" || shift;;
+	--bindir) read_arg bindir "$@" || shift;;
+	--sbindir) read_arg sbindir "$@" || shift;;
+	--libexecdir) read_arg libexecdir "$@" || shift;;
+	--datarootdir) read_arg datarootdir "$@" || shift;;
+	--datadir) read_arg datadir "$@" || shift;;
+	--sysconfdir) read_arg sysconfdir "$@" || shift;;
+	--libdir) read_arg libdir "$@" || shift;;
+	--mandir) read_arg mandir "$@" || shift;;
+	--includedir) read_arg includedir "$@" || shift;;
+	--enable-gtk-doc) enable_docs='-Denable-gtk-doc=true';;
+	--disable-gtk-doc) enable_docs='-Denable-gtk-doc=false';;
+	--enable-man) enable_man='-Denable-man=true';;
+	--disable-man) enable_man='-Denable-man=false';;
+	--enable-introspection) enable_introspection='';;
+	--disable-introspection) enable_introspection='-Ddisable_introspection=true';;
+	*) echo -e "\e[1;33mINFO\e[0m: Ignoring unknown option '$1'";;
+    esac
+    shift
+done
+
+# Defaults
+test -z ${prefix} && prefix="/usr/local"
+test -z ${bindir} && bindir=${prefix}/bin
+test -z ${sbindir} && sbindir=${prefix}/sbin
+test -z ${libexecdir} && libexecdir=${prefix}/bin
+test -z ${datarootdir} && datarootdir=${prefix}/share
+test -z ${datadir} && datadir=${datarootdir}
+test -z ${sysconfdir} && sysconfdir=${prefix}/etc
+test -z ${libdir} && libdir=${prefix}/lib
+test -z ${mandir} && mandir=${prefix}/share/man
+test -z ${includedir} && includedir=${prefix}/include
+
+# The source directory is the location of this file
+srcdir=$(dirname $0)
+
+# The build directory is the current location
+builddir=`pwd`
+
+# If we're calling this file from the source directory then
+# we automatically create a build directory and ensure that
+# both Meson and Ninja invocations are relative to that
+# location
+if [[ -f "${builddir}/meson.build" ]]; then
+  mkdir -p _build
+  builddir="${builddir}/_build"
+  NINJA_OPT="-C ${builddir}"
+fi
+
+# Wrapper Makefile for Ninja
+cat > Makefile <<END
+# Generated by configure; do not edit
+
+all:
+	CC="\$(CC)" CXX="\$(CXX)" ${NINJA} ${NINJA_OPT}
+
+install:
+	DESTDIR="\$(DESTDIR)" ${NINJA} ${NINJA_OPT} install
+
+check:
+	${MESONTEST} ${NINJA_OPT}
+END
+
+echo "Summary:"
+echo "  meson:....... ${MESON}"
+echo "  ninja:....... ${NINJA}"
+echo "  prefix:...... ${prefix}"
+echo "  bindir:...... ${bindir}"
+echo "  sbindir:..... ${sbindir}"
+echo "  libexecdir:.. ${libexecdir}"
+echo "  datarootdir:. ${datarootdir}"
+echo "  datadir:..... ${datadir}"
+echo "  sysconfdir:.. ${sysconfdir}"
+echo "  libdir:...... ${libdir}"
+echo "  mandir:...... ${mandir}"
+echo "  includedir:.. ${includedir}"
+echo "  additional:.."
+echo "    - ${enable_docs} ${enable_man} ${enable_introspection}"
+
+exec ${MESON} \
+	--prefix=${prefix} \
+	--libdir=${libdir} \
+	--libexecdir=${libexecdir} \
+	--datadir=${datadir} \
+	--sysconfdir=${sysconfdir} \
+	--bindir=${bindir} \
+	--includedir=${includedir} \
+	--mandir=${mandir} \
+	--default-library shared \
+	${enable_docs} \
+	${enable_man} \
+	${enable_introspection} \
+	${builddir} \
+	${srcdir}
+
+# vim: ai ts=8 noet sts=2 ft=sh