configure: rename --enable-pypi to --enable-download, control subprojects too

The behavior of --{enable,disable}-pypi is similar to that of
-Dwrapmode={default,nodownload} respectively.  In particular,
in both cases a feature needs to be explicitly enabled for the
dependency to be downloaded.

So, use a single option to control both cases.  Now, --enable-slirp
will trigger cloning and building of libslirp if the .pc file
is not found on the machine.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

.gitignore

@@ -20,5 +20,3 @@ GTAGS
 *.swp
 *.patch
 *.gcov
-
-/subprojects/slirp

configure

@@ -266,7 +266,7 @@ bsd_user=""
 plugins="$default_feature"
 ninja=""
 python=
-pypi="enabled"
+download="enabled"
 bindir="bin"
 skip_meson=no
 vfio_user_server="disabled"
@@ -754,9 +754,9 @@ for opt do
   --with-git-submodules=*)
       git_submodules_action="$optarg"
   ;;
-  --disable-pypi) pypi="disabled"
+  --disable-download) download="disabled"
   ;;
-  --enable-pypi) pypi="enabled"
+  --enable-download) download="enabled"
   ;;
   --enable-plugins) if test "$mingw32" = "yes"; then
                         error_exit "TCG plugins not currently supported on Windows platforms"
@@ -960,7 +960,7 @@ python="$(command -v "$python")"
 # - venv is allowed to use system packages;
 # - all setup can be performed offline;
 # - missing packages may be fetched from PyPI,
-#   unless --disable-pypi is passed.
+#   unless --disable-download is passed.
 # - pip is not installed into the venv when possible,
 #   but ensurepip is called as a fallback when necessary.
 
@@ -977,7 +977,7 @@ python="$python -B"
 mkvenv="$python ${source_path}/python/scripts/mkvenv.py"
 
 mkvenv_flags=""
-if test "$pypi" = "enabled" ; then
+if test "$download" = "enabled" ; then
     mkvenv_flags="--online"
 fi
 
@@ -1000,7 +1000,7 @@ meson="$(cd pyvenv/bin; pwd)/meson"
 # Conditionally ensure Sphinx is installed.
 
 mkvenv_flags=""
-if test "$pypi" = "enabled" -a "$docs" = "enabled" ; then
+if test "$download" = "enabled" -a "$docs" = "enabled" ; then
     mkvenv_flags="--online"
 fi
 
@@ -1940,11 +1940,8 @@ if test "$skip_meson" = no; then
 
   rm -rf meson-private meson-info meson-logs
 
-  # Prevent meson from automatically downloading wrapped subprojects when missing.
-  # You can use 'meson subprojects download' before running configure.
-  meson_option_add "--wrap-mode=nodownload"
-
   # Built-in options
+  test "$download" = "disabled" && meson_option_add "--wrap-mode=nodownload"
   test "$bindir" != "bin" && meson_option_add "-Dbindir=$bindir"
   test "$default_feature" = no && meson_option_add -Dauto_features=disabled
   test "$static" = yes && meson_option_add -Dprefer_static=true

meson.build

@@ -3985,8 +3985,15 @@ endif
 # Configuration summary #
 #########################
 
-# Directories
+# Build environment
 summary_info = {}
+summary_info += {'Build directory':   meson.current_build_dir()}
+summary_info += {'Source path':       meson.current_source_dir()}
+summary_info += {'GIT submodules':    config_host['GIT_SUBMODULES']}
+summary_info += {'Download dependencies': get_option('wrap_mode') != 'nodownload'}
+summary(summary_info, bool_yn: true, section: 'Build environment')
+
+# Directories
 summary_info += {'Install prefix':    get_option('prefix')}
 summary_info += {'BIOS directory':    qemu_datadir}
 pathsep = targetos == 'windows' ? ';' : ':'
@@ -4004,9 +4011,6 @@ else
   summary_info += {'local state directory': 'queried at runtime'}
 endif
 summary_info += {'Doc directory':     get_option('prefix') / get_option('docdir')}
-summary_info += {'Build directory':   meson.current_build_dir()}
-summary_info += {'Source path':       meson.current_source_dir()}
-summary_info += {'GIT submodules':    config_host['GIT_SUBMODULES']}
 summary(summary_info, bool_yn: true, section: 'Directories')
 
 # Host binaries

subprojects/.gitignore

@@ -0,0 +1,3 @@
+/packagecache
+
+/slirp