configure: move target-specific defaults to an external machine file

Enable Windows-specific defaults with a machine file, so that related
options can be automatically parsed and included in the help message.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -246,8 +246,6 @@ default_cflags='-O2 -g'
 git_submodules_action="update"
 docs="auto"
 EXESUF=""
-prefix="/usr/local"
-qemu_suffix="qemu"
 system="yes"
 linux_user=""
 bsd_user=""
@@ -256,7 +254,6 @@ subdirs=""
 ninja=""
 python=
 download="enabled"
-bindir="bin"
 skip_meson=no
 use_containers="yes"
 gdb_bin=$(command -v "gdb-multiarch" || command -v "gdb")
@@ -583,9 +580,6 @@ done
 
 if test "$targetos" = "windows" ; then
   EXESUF=".exe"
-  prefix="/qemu"
-  bindir=""
-  qemu_suffix=""
 fi
 
 meson_option_build_array() {
@@ -622,6 +616,14 @@ meson_option_parse() {
   fi
 }
 
+meson_add_machine_file() {
+  if test "$cross_compile" = "yes"; then
+    meson_option_add --cross-file "$1"
+  else
+    meson_option_add --native-file "$1"
+  fi
+}
+
 for opt do
   optarg=$(expr "x$opt" : 'x[^=]*=\(.*\)')
   case "$opt" in
@@ -629,8 +631,6 @@ for opt do
   ;;
   --version|-V) exec cat "$source_path/VERSION"
   ;;
-  --prefix=*) prefix="$optarg"
-  ;;
   --cross-prefix=*)
   ;;
   --cc=*)
@@ -701,10 +701,6 @@ for opt do
   ;;
   --static) static="yes"
   ;;
-  --bindir=*) bindir="$optarg"
-  ;;
-  --with-suffix=*) qemu_suffix="$optarg"
-  ;;
   --host=*|--build=*|\
   --disable-dependency-tracking|\
   --sbindir=*|--sharedstatedir=*|\
@@ -861,7 +857,6 @@ Options: [defaults in brackets after descriptions]
 
 Standard options:
   --help                   print this message
-  --prefix=PREFIX          install in PREFIX [$prefix]
   --target-list=LIST       set target list (default: build all)
 $(echo Available targets: $default_target_list | \
   fold -s -w 53 | sed -e 's/^/                           /')
@@ -886,8 +881,6 @@ Advanced options (experts only):
   --ninja=NINJA            use specified ninja [$ninja]
   --smbd=SMBD              use specified smbd [$smbd]
   --static                 enable static build [$static]
-  --bindir=PATH            install binaries in PATH
-  --with-suffix=SUFFIX     suffix for QEMU data inside datadir/libdir/sysconfdir/docdir [$qemu_suffix]
   --without-default-features default all --enable-* options to "disabled"
   --without-default-devices  do not include any device that is not needed to
                            start the emulator (only use if you are including
@@ -1803,24 +1796,25 @@ if test "$skip_meson" = no; then
     else
         echo "endian = 'little'" >> $cross
     fi
-    cross_arg="--cross-file config-meson.cross"
 
     native="config-meson.native.new"
     echo "# Automatically generated by configure - do not modify" > $native
     echo "[binaries]" >> $native
     echo "c = [$(meson_quote $host_cc)]" >> $native
     mv $native config-meson.native
-    cross_arg="$cross_arg --native-file config-meson.native"
-  else
-    cross_arg="--native-file config-meson.cross"
+    meson_option_add --native-file
+    meson_option_add config-meson.native
   fi
   mv $cross config-meson.cross
+  meson_add_machine_file config-meson.cross
+  if test -f "$source_path/configs/meson/$targetos.txt"; then
+    meson_add_machine_file $source_path/configs/meson/$targetos.txt
+  fi
 
   rm -rf meson-private meson-info meson-logs
 
   # 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 "$static" = yes && meson_option_add -Dprefer_static=true
   test "$pie" = no && meson_option_add -Db_pie=false
@@ -1831,11 +1825,10 @@ if test "$skip_meson" = no; then
   test "$docs" != auto && meson_option_add "-Ddocs=$docs"
   test -n "${LIB_FUZZING_ENGINE+xxx}" && meson_option_add "-Dfuzzing_engine=$LIB_FUZZING_ENGINE"
   test "$plugins" = yes && meson_option_add "-Dplugins=true"
-  test "$qemu_suffix" != qemu && meson_option_add "-Dqemu_suffix=$qemu_suffix"
   test "$smbd" != '' && meson_option_add "-Dsmbd=$smbd"
   test "$tcg" != enabled && meson_option_add "-Dtcg=$tcg"
   run_meson() {
-    NINJA=$ninja $meson setup --prefix "$prefix" "$@" $cross_arg "$PWD" "$source_path"
+    NINJA=$ninja $meson setup "$@" "$PWD" "$source_path"
   }
   eval run_meson $meson_options
   if test "$?" -ne 0 ; then