[PATCH 21/27] configure: bootstrap sphinx with mkvenv

[John Snow <jsnow@redhat.com>]

When docs are explicitly requested, require Sphinx>=1.6.0. When docs are
explicitly disabled, don't bother to check for Sphinx at all. If docs
are set to "auto", attempt to locate Sphinx, but continue onward if it
wasn't located.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
---
 docs/conf.py                  |  9 ---------
 docs/meson.build              |  2 +-
 configure                     | 21 +++++++++++++++++++--
 meson_options.txt             |  2 --
 scripts/meson-buildoptions.sh |  3 ---
 5 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/docs/conf.py b/docs/conf.py
index 00767b0e24..c687ff2663 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -32,15 +32,6 @@
 from distutils.version import LooseVersion
 from sphinx.errors import ConfigError
 
-# Make Sphinx fail cleanly if using an old Python, rather than obscurely
-# failing because some code in one of our extensions doesn't work there.
-# In newer versions of Sphinx this will display nicely; in older versions
-# Sphinx will also produce a Python backtrace but at least the information
-# gets printed...
-if sys.version_info < (3,6):
-    raise ConfigError(
-        "QEMU requires a Sphinx that uses Python 3.6 or better\n")
-
 # The per-manual conf.py will set qemu_docdir for a single-manual build;
 # otherwise set it here if this is an entire-manual-set build.
 # This is always the absolute path of the docs/ directory in the source tree.
diff --git a/docs/meson.build b/docs/meson.build
index f220800e3e..e4301703b4 100644
--- a/docs/meson.build
+++ b/docs/meson.build
@@ -1,4 +1,4 @@
-sphinx_build = find_program(get_option('sphinx_build'),
+sphinx_build = find_program(fs.parent(python.full_path()) / 'sphinx-build',
                             required: get_option('docs'))
 
 # Check if tools are available to build documentation.
diff --git a/configure b/configure
index 3e74c54f29..77d632e10d 100755
--- a/configure
+++ b/configure
@@ -1116,9 +1116,9 @@ fi
 
 # Suppress writing compiled files
 python="$python -B"
+mkvenv="$python ${source_path}/python/scripts/mkvenv.py"
 
-
-if ! $python "${source_path}/python/scripts/mkvenv.py" ensure \
+if ! $mkvenv ensure \
      --dir "${source_path}/python/wheels" \
      --diagnose "meson" \
      "meson>=0.61.5" ;
@@ -1147,6 +1147,23 @@ else
   meson="$(cd pyvenv/bin; pwd)/meson"
 fi
 
+# Conditionally ensure Sphinx is installed.
+
+if test "$docs" != "disabled" ; then
+    if ! $mkvenv ensure \
+         --diagnose "sphinx-build" \
+         "sphinx>=1.6.0" sphinx_rtd_theme;
+    then
+        if test "$docs" = "enabled" ; then
+            exit 1
+        fi
+        echo "Sphinx not found/usable, disabling docs."
+        docs=disabled
+    else
+        docs=enabled
+    fi
+fi
+
 # Probe for ninja
 
 if test -z "$ninja"; then
diff --git a/meson_options.txt b/meson_options.txt
index d8330a1f71..a350520f6a 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -12,8 +12,6 @@ option('pkgversion', type : 'string', value : '',
        description: 'use specified string as sub-version of the package')
 option('smbd', type : 'string', value : '',
        description: 'Path to smbd for slirp networking')
-option('sphinx_build', type : 'string', value : 'sphinx-build',
-       description: 'Use specified sphinx-build for building document')
 option('iasl', type : 'string', value : '',
        description: 'Path to ACPI disassembler')
 option('tls_priority', type : 'string', value : 'NORMAL',
diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index 2805d1c145..fedb93ada6 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -57,8 +57,6 @@ meson_options_help() {
   printf "%s\n" '  --localedir=VALUE        Locale data directory [share/locale]'
   printf "%s\n" '  --localstatedir=VALUE    Localstate data directory [/var/local]'
   printf "%s\n" '  --mandir=VALUE           Manual page directory [share/man]'
-  printf "%s\n" '  --sphinx-build=VALUE     Use specified sphinx-build for building document'
-  printf "%s\n" '                           [sphinx-build]'
   printf "%s\n" '  --sysconfdir=VALUE       Sysconf data directory [etc]'
   printf "%s\n" '  --tls-priority=VALUE     Default TLS protocol/cipher priority string'
   printf "%s\n" '                           [NORMAL]'
@@ -425,7 +423,6 @@ _meson_option_parse() {
     --disable-sndio) printf "%s" -Dsndio=disabled ;;
     --enable-sparse) printf "%s" -Dsparse=enabled ;;
     --disable-sparse) printf "%s" -Dsparse=disabled ;;
-    --sphinx-build=*) quote_sh "-Dsphinx_build=$2" ;;
     --enable-spice) printf "%s" -Dspice=enabled ;;
     --disable-spice) printf "%s" -Dspice=disabled ;;
     --enable-spice-protocol) printf "%s" -Dspice_protocol=enabled ;;
-- 
2.40.0