xbps-src: refactor build logic into its own script (build.sh).

The build.sh script is now responsible to handle all the logic to build
a source package and its subpackages, as well as all its required
build dependencies. Thanks to this and subshells, dependencies are now
built into its own child process, creating a process tree that can go
nested as long as your system allows forking and has enough memory :-)

This fixes some issues that have been while building pkgs that have lots
of nested dependencies.

common/xbps-src/libexec/build.sh

@@ -0,0 +1,104 @@
+#!/bin/bash
+#
+# vim: set ts=4 sw=4 et:
+#
+# Passed arguments:
+#   $1 - current pkgname to build [REQUIRED]
+#   $2 - target pkgname (origin) to build [REQUIRED]
+#   $3 - xbps target [REQUIRED]
+#   $4 - cross target [OPTIONAL]
+
+if [ $# -lt 3 -o $# -gt 4 ]; then
+    echo "$(basename $0): invalid number of arguments: pkgname targetpkg target [cross-target]"
+    exit 1
+fi
+
+readonly PKGNAME="$1"
+readonly TARGET_PKG="$2"
+readonly TARGET="$3"
+readonly XBPS_CROSS_BUILD="$4"
+
+for f in $XBPS_SHUTILSDIR/*.sh; do
+    . $f
+done
+
+setup_pkg "$PKGNAME" $XBPS_CROSS_BUILD
+show_pkg_build_options
+check_pkg_arch $XBPS_CROSS_BUILD
+install_cross_pkg $XBPS_CROSS_BUILD
+
+# Install dependencies from binary packages
+if [ -z "$XBPS_SKIP_DEPS" ]; then
+    install_pkg_deps $PKGNAME $TARGET_PKG $TARGET $XBPS_CROSS_BUILD || exit 1
+fi
+
+# Fetch distfiles after installing required dependencies,
+# because some of them might be required for do_fetch().
+$XBPS_LIBEXECDIR/xbps-src-dofetch.sh $PKGNAME $XBPS_CROSS_BUILD || exit 1
+[ "$TARGET" = "fetch" ] && exit 0
+
+# Fetch, extract, build and install into the destination directory.
+$XBPS_LIBEXECDIR/xbps-src-doextract.sh $PKGNAME $XBPS_CROSS_BUILD || exit 1
+[ "$TARGET" = "extract" ] && exit 0
+
+# Run configure phase
+$XBPS_LIBEXECDIR/xbps-src-doconfigure.sh $PKGNAME $XBPS_CROSS_BUILD || exit 1
+[ "$TARGET" = "configure" ] && exit 0
+
+# Run build phase
+$XBPS_LIBEXECDIR/xbps-src-dobuild.sh $PKGNAME $XBPS_CROSS_BUILD || exit 1
+[ "$TARGET" = "build" ] && exit 0
+
+# Install pkgs into destdir.
+$XBPS_LIBEXECDIR/xbps-src-doinstall.sh $PKGNAME $XBPS_CROSS_BUILD || exit 1
+
+for subpkg in ${subpackages} ${sourcepkg}; do
+    $XBPS_LIBEXECDIR/xbps-src-doinstall.sh $subpkg $XBPS_CROSS_BUILD || exit 1
+done
+for subpkg in ${subpackages} ${sourcepkg}; do
+    $XBPS_LIBEXECDIR/xbps-src-prepkg.sh $subpkg $XBPS_CROSS_BUILD || exit 1
+done
+
+for subpkg in ${subpackages} ${sourcepkg}; do
+    if [ "$PKGNAME" = "${subpkg}" -a "$TARGET" = "install" ]; then
+        exit 0
+    fi
+done
+
+# If install went ok generate the binpkgs.
+for subpkg in ${subpackages} ${sourcepkg}; do
+    $XBPS_LIBEXECDIR/xbps-src-dopkg.sh $subpkg "$XBPS_REPOSITORY" "$XBPS_CROSS_BUILD" || exit 1
+done
+
+# pkg cleanup
+if declare -f do_clean >/dev/null; then
+    run_func do_clean
+fi
+
+if [ -z "$XBPS_KEEP_ALL" ]; then
+    remove_pkg_autodeps
+    remove_pkg_wrksrc
+    remove_pkg $XBPS_CROSS_BUILD
+    remove_pkg_statedir
+fi
+
+# If base-chroot not installed, install "base-files" into masterdir
+# from local repository; this is the only pkg required to be able to build
+# the bootstrap pkgs from scratch.
+if [ -z "$CHROOT_READY" -a "$PKGNAME" = "base-files" ]; then
+    msg_normal "Installing $PKGNAME into masterdir...\n"
+    _log=$(mktemp --tmpdir || exit 1)
+    if [ -n "$XBPS_BUILD_FORCEMODE" ]; then
+        _flags="-f"
+    fi
+    $XBPS_INSTALL_CMD ${_flags} -y $PKGNAME >${_log} 2>&1
+    if [ $? -ne 0 ]; then
+        msg_red "Failed to install $PKGNAME into masterdir, see below for errors:\n"
+        cat ${_log}
+        rm -f ${_log}
+        msg_error "Cannot continue!"
+    fi
+    rm -f ${_log}
+fi
+
+exit 0