meson: Move the detection logic for sphinx to meson

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Message-Id: <20201015220626.418-4-luoyonggang@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -297,7 +297,7 @@ brlapi=""
 curl=""
 iconv="auto"
 curses="auto"
-docs=""
+docs="auto"
 fdt="auto"
 netmap="no"
 sdl="auto"
@@ -820,15 +820,6 @@ do
     fi
 done
 
-sphinx_build=
-for binary in sphinx-build-3 sphinx-build
-do
-    if has "$binary"
-    then
-        sphinx_build=$(command -v "$binary")
-        break
-    fi
-done
 
 # Check for ancillary tools used in testing
 genisoimage=
@@ -1228,9 +1219,9 @@ for opt do
   ;;
   --disable-crypto-afalg) crypto_afalg="no"
   ;;
-  --disable-docs) docs="no"
+  --disable-docs) docs="disabled"
   ;;
-  --enable-docs) docs="yes"
+  --enable-docs) docs="enabled"
   ;;
   --disable-vhost-net) vhost_net="no"
   ;;
@@ -4419,45 +4410,6 @@ if check_include linux/btrfs.h ; then
     btrfs=yes
 fi
 
-# If we're making warnings fatal, apply this to Sphinx runs as well
-sphinx_werror=""
-if test "$werror" = "yes"; then
-    sphinx_werror="-W"
-fi
-
-# Check we have a new enough version of sphinx-build
-has_sphinx_build() {
-    # This is a bit awkward but works: create a trivial document and
-    # try to run it with our configuration file (which enforces a
-    # version requirement). This will fail if either
-    # sphinx-build doesn't exist at all or if it is too old.
-    mkdir -p "$TMPDIR1/sphinx"
-    touch "$TMPDIR1/sphinx/index.rst"
-    "$sphinx_build" $sphinx_werror -c "$source_path/docs" \
-                    -b html "$TMPDIR1/sphinx" \
-                    "$TMPDIR1/sphinx/out"  >> config.log 2>&1
-}
-
-# Check if tools are available to build documentation.
-if test "$docs" != "no" ; then
-  if has_sphinx_build; then
-    sphinx_ok=yes
-  else
-    sphinx_ok=no
-  fi
-  if test "$sphinx_ok" = "yes"; then
-    docs=yes
-  else
-    if test "$docs" = "yes" ; then
-      if has $sphinx_build && test "$sphinx_ok" != "yes"; then
-        echo "Warning: $sphinx_build exists but it is either too old or uses too old a Python version" >&2
-      fi
-      feature_not_found "docs" "Install a Python 3 version of python-sphinx"
-    fi
-    docs=no
-  fi
-fi
-
 # Search for bswap_32 function
 byteswap_h=no
 cat > $TMPC << EOF
@@ -6093,9 +6045,6 @@ qemu_version=$(head $source_path/VERSION)
 echo "PKGVERSION=$pkgversion" >>$config_host_mak
 echo "SRC_PATH=$source_path" >> $config_host_mak
 echo "TARGET_DIRS=$target_list" >> $config_host_mak
-if [ "$docs" = "yes" ] ; then
-  echo "BUILD_DOCS=yes" >> $config_host_mak
-fi
 if test "$modules" = "yes"; then
   # $shacmd can generate a hash started with digit, which the compiler doesn't
   # like as an symbol. So prefix it with an underscore
@@ -6784,7 +6733,6 @@ fi
 echo "ROMS=$roms" >> $config_host_mak
 echo "MAKE=$make" >> $config_host_mak
 echo "PYTHON=$python" >> $config_host_mak
-echo "SPHINX_BUILD=$sphinx_build" >> $config_host_mak
 echo "GENISOIMAGE=$genisoimage" >> $config_host_mak
 echo "MESON=$meson" >> $config_host_mak
 echo "NINJA=$ninja" >> $config_host_mak
@@ -7066,6 +7014,7 @@ NINJA=$ninja $meson setup \
         -Dgettext=$gettext -Dxkbcommon=$xkbcommon -Du2f=$u2f \
         -Dcapstone=$capstone -Dslirp=$slirp -Dfdt=$fdt \
         -Diconv=$iconv -Dcurses=$curses -Dlibudev=$libudev\
+        -Ddocs=$docs -Dsphinx_build=$sphinx_build \
         $cross_arg \
         "$PWD" "$source_path"