docs: Build and install all the docs in a single manual

When we first converted our documentation to Sphinx, we split it into
multiple manuals (system, interop, tools, etc), which are all built
separately.  The primary driver for this was wanting to be able to
avoid shipping the 'devel' manual to end-users.  However, this is
working against the grain of the way Sphinx wants to be used and
causes some annoyances:
 * Cross-references between documents become much harder or
   possibly impossible
 * There is no single index to the whole documentation
 * Within one manual there's no links or table-of-contents info
   that lets you easily navigate to the others
 * The devel manual doesn't get published on the QEMU website
   (it would be nice to able to refer to it there)

Merely hiding our developer documentation from end users seems like
it's not enough benefit for these costs.  Combine all the
documentation into a single manual (the same way that the readthedocs
site builds it) and install the whole thing.  The previous manual
divisions remain as the new top level sections in the manual.

 * The per-manual conf.py files are no longer needed
 * The man_pages[] specifications previously in each per-manual
   conf.py move to the top level conf.py
 * docs/meson.build logic is simplified as we now only need to run
   Sphinx once for the HTML and then once for the manpages5B
 * The old index.html.in that produced the top-level page with
   links to each manual is no longer needed

Unfortunately this means that we now have to build the HTML
documentation into docs/manual in the build tree rather than directly
into docs/; otherwise it is too awkward to ensure we install only the
built manual and not also the dependency info, stamp file, etc.  The
manual still ends up in the same place in the final installed
directory, but anybody who was consulting documentation from within
the build tree will have to adjust where they're looking.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20210108161416.21129-3-peter.maydell@linaro.org

docs/conf.py

@@ -224,7 +224,51 @@
 
 # -- Options for manual page output ---------------------------------------
 # Individual manual/conf.py can override this to create man pages
-man_pages = []
+man_pages = [
+    ('interop/qemu-ga', 'qemu-ga',
+     'QEMU Guest Agent',
+     ['Michael Roth <mdroth@linux.vnet.ibm.com>'], 8),
+    ('interop/qemu-ga-ref', 'qemu-ga-ref',
+     'QEMU Guest Agent Protocol Reference',
+     [], 7),
+    ('interop/qemu-qmp-ref', 'qemu-qmp-ref',
+     'QEMU QMP Reference Manual',
+     [], 7),
+    ('interop/qemu-storage-daemon-qmp-ref', 'qemu-storage-daemon-qmp-ref',
+     'QEMU Storage Daemon QMP Reference Manual',
+     [], 7),
+    ('system/qemu-manpage', 'qemu',
+     'QEMU User Documentation',
+     ['Fabrice Bellard'], 1),
+    ('system/qemu-block-drivers', 'qemu-block-drivers',
+     'QEMU block drivers reference',
+     ['Fabrice Bellard and the QEMU Project developers'], 7),
+    ('system/qemu-cpu-models', 'qemu-cpu-models',
+     'QEMU CPU Models',
+     ['The QEMU Project developers'], 7),
+    ('tools/qemu-img', 'qemu-img',
+     'QEMU disk image utility',
+     ['Fabrice Bellard'], 1),
+    ('tools/qemu-nbd', 'qemu-nbd',
+     'QEMU Disk Network Block Device Server',
+     ['Anthony Liguori <anthony@codemonkey.ws>'], 8),
+    ('tools/qemu-pr-helper', 'qemu-pr-helper',
+     'QEMU persistent reservation helper',
+     [], 8),
+    ('tools/qemu-storage-daemon', 'qemu-storage-daemon',
+     'QEMU storage daemon',
+     [], 1),
+    ('tools/qemu-trace-stap', 'qemu-trace-stap',
+     'QEMU SystemTap trace tool',
+     [], 1),
+    ('tools/virtfs-proxy-helper', 'virtfs-proxy-helper',
+     'QEMU 9p virtfs proxy filesystem helper',
+     ['M. Mohan Kumar'], 1),
+    ('tools/virtiofsd', 'virtiofsd',
+     'QEMU virtio-fs shared file system daemon',
+     ['Stefan Hajnoczi <stefanha@redhat.com>',
+      'Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>'], 1),
+]
 
 # -- Options for Texinfo output -------------------------------------------
 

docs/meson.build

@@ -46,73 +46,59 @@ if build_docs
                           meson.source_root() / 'docs/sphinx/qmp_lexer.py',
                           qapi_gen_depends ]
 
-  configure_file(output: 'index.html',
-                 input: files('index.html.in'),
-                 configuration: {'VERSION': meson.project_version()},
-                 install_dir: qemu_docdir)
-  manuals = [ 'devel', 'interop', 'tools', 'specs', 'system', 'user' ]
   man_pages = {
-    'interop' : {
         'qemu-ga.8': (have_tools ? 'man8' : ''),
         'qemu-ga-ref.7': 'man7',
         'qemu-qmp-ref.7': 'man7',
         'qemu-storage-daemon-qmp-ref.7': (have_tools ? 'man7' : ''),
-    },
-    'tools': {
         'qemu-img.1': (have_tools ? 'man1' : ''),
         'qemu-nbd.8': (have_tools ? 'man8' : ''),
         'qemu-pr-helper.8': (have_tools ? 'man8' : ''),
         'qemu-storage-daemon.1': (have_tools ? 'man1' : ''),
         'qemu-trace-stap.1': (config_host.has_key('CONFIG_TRACE_SYSTEMTAP') ? 'man1' : ''),
         'virtfs-proxy-helper.1': (have_virtfs_proxy_helper ? 'man1' : ''),
         'virtiofsd.1': (have_virtiofsd ? 'man1' : ''),
-    },
-    'system': {
         'qemu.1': 'man1',
         'qemu-block-drivers.7': 'man7',
         'qemu-cpu-models.7': 'man7'
-    },
   }
 
   sphinxdocs = []
   sphinxmans = []
-  foreach manual : manuals
-    private_dir = meson.current_build_dir() / (manual + '.p')
-    output_dir = meson.current_build_dir() / manual
-    input_dir = meson.current_source_dir() / manual
 
-    this_manual = custom_target(manual + ' manual',
+  private_dir = meson.current_build_dir() / 'manual.p'
+  output_dir = meson.current_build_dir() / 'manual'
+  input_dir = meson.current_source_dir()
+
+  this_manual = custom_target('QEMU manual',
                 build_by_default: build_docs,
-                output: [manual + '.stamp'],
-                input: [files('conf.py'), files(manual / 'conf.py')],
-                depfile: manual + '.d',
+                output: 'docs.stamp',
+                input: files('conf.py'),
+                depfile: 'docs.d',
                 depend_files: sphinx_extn_depends,
                 command: [SPHINX_ARGS, '-Ddepfile=@DEPFILE@',
                           '-Ddepfile_stamp=@OUTPUT0@',
                           '-b', 'html', '-d', private_dir,
                           input_dir, output_dir])
-    sphinxdocs += this_manual
-    if build_docs and manual != 'devel'
-      install_subdir(output_dir, install_dir: qemu_docdir)
-    endif
+  sphinxdocs += this_manual
+  install_subdir(output_dir, install_dir: qemu_docdir, strip_directory: true)
 
-    these_man_pages = []
-    install_dirs = []
-    foreach page, section : man_pages.get(manual, {})
-      these_man_pages += page
-      install_dirs += section == '' ? false : get_option('mandir') / section
-    endforeach
-    if these_man_pages.length() > 0
-      sphinxmans += custom_target(manual + ' man pages',
-                         build_by_default: build_docs,
-                         output: these_man_pages,
-                         input: this_manual,
-                         install: build_docs,
-                         install_dir: install_dirs,
-                         command: [SPHINX_ARGS, '-b', 'man', '-d', private_dir,
-                                   input_dir, meson.current_build_dir()])
-    endif
+  these_man_pages = []
+  install_dirs = []
+  foreach page, section : man_pages
+    these_man_pages += page
+    install_dirs += section == '' ? false : get_option('mandir') / section
   endforeach
+
+  sphinxmans += custom_target('QEMU man pages',
+                              build_by_default: build_docs,
+                              output: these_man_pages,
+                              input: this_manual,
+                              install: build_docs,
+                              install_dir: install_dirs,
+                              command: [SPHINX_ARGS, '-b', 'man', '-d', private_dir,
+                                        input_dir, meson.current_build_dir()])
+
   alias_target('sphinxdocs', sphinxdocs)
   alias_target('html', sphinxdocs)
   alias_target('man', sphinxmans)