[backport] Improve doxygen (#8959) (#9284)

* Remove Sphinx build from GH Action

* Build Doxygen as part of RTD build

* Add jQuery

Co-authored-by: Philip Hyunsu Cho <chohyu01@cs.washington.edu>

.github/workflows/main.yml

@@ -148,66 +148,13 @@ jobs:
       run: |
         LINT_LANG=cpp make lint
 
-  doxygen:
-    runs-on: ubuntu-latest
-    name: Generate C/C++ API doc using Doxygen
-    steps:
-    - uses: actions/checkout@v2
-      with:
-        submodules: 'true'
-    - uses: actions/setup-python@v2
-      with:
-        python-version: "3.8"
-        architecture: 'x64'
-    - name: Install system packages
-      run: |
-        sudo apt-get install -y --no-install-recommends doxygen graphviz ninja-build
-        python -m pip install wheel setuptools
-        python -m pip install awscli
-    - name: Run Doxygen
-      run: |
-        mkdir build
-        cd build
-        cmake .. -DBUILD_C_DOC=ON -GNinja
-        ninja -v doc_doxygen
-    - name: Extract branch name
-      shell: bash
-      run: echo "##[set-output name=branch;]$(echo ${GITHUB_REF#refs/heads/})"
-      id: extract_branch
-      if: github.ref == 'refs/heads/master' || contains(github.ref, 'refs/heads/release_')
-    - name: Publish
-      run: |
-        cd build/
-        tar cvjf ${{ steps.extract_branch.outputs.branch }}.tar.bz2 doc_doxygen/
-        python -m awscli s3 cp ./${{ steps.extract_branch.outputs.branch }}.tar.bz2 s3://xgboost-docs/doxygen/ --acl public-read
-      if: github.ref == 'refs/heads/master' || contains(github.ref, 'refs/heads/release_')
-      env:
-        AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID_IAM_S3_UPLOADER }}
-        AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY_IAM_S3_UPLOADER }}
-
-  sphinx:
-    runs-on: ubuntu-latest
-    name: Build docs using Sphinx
-    steps:
-    - uses: actions/checkout@v2
-      with:
-        submodules: 'true'
-    - uses: actions/setup-python@v2
-      with:
-        python-version: "3.8"
-        architecture: 'x64'
-    - name: Install system packages
-      run: |
-        sudo apt-get install -y --no-install-recommends graphviz
-        python -m pip install wheel setuptools
-        python -m pip install -r doc/requirements.txt
-    - name: Extract branch name
-      shell: bash
-      run: echo "##[set-output name=branch;]$(echo ${GITHUB_REF#refs/heads/})"
-      id: extract_branch
-      if: github.ref == 'refs/heads/master' || contains(github.ref, 'refs/heads/release_')
-    - name: Run Sphinx
-      run: |
-        make -C doc html
-      env:
-        SPHINX_GIT_BRANCH: ${{ steps.extract_branch.outputs.branch }}
+        python3 dmlc-core/scripts/lint.py --exclude_path \
+            python-package/xgboost/dmlc-core \
+            python-package/xgboost/include \
+            python-package/xgboost/lib \
+            python-package/xgboost/rabit \
+            python-package/xgboost/src \
+            --pylint-rc python-package/.pylintrc \
+            xgboost \
+            cpp \
+            include src python-package

doc/c++.rst

@@ -8,5 +8,5 @@ As a result it's changing quite often and we don't maintain its stability.  Alon
 plugin system (see ``plugin/example`` in XGBoost's source tree), users can utilize some
 existing c++ headers for gaining more access to the internal of XGBoost.
 
-* `C++ interface documentation (latest master branch) <https://xgboost.readthedocs.io/en/latest/dev/files.html>`_
+* `C++ interface documentation (latest master branch) <./dev/files.html>`_
 * `C++ interface documentation (last stable release) <https://xgboost.readthedocs.io/en/stable/dev/files.html>`_

doc/c.rst

@@ -10,7 +10,7 @@ simply look at function comments in ``include/xgboost/c_api.h``. The reference i
 to sphinx with the help of breathe, which doesn't contain links to examples but might be
 easier to read. For the original doxygen pages please visit:
 
-* `C API documentation (latest master branch) <https://xgboost.readthedocs.io/en/latest/dev/c__api_8h.html>`_
+* `C API documentation (latest master branch) <./dev/c__api_8h.html>`_
 * `C API documentation (last stable release) <https://xgboost.readthedocs.io/en/stable/dev/c__api_8h.html>`_
 
 ***************

doc/conf.py

@@ -11,54 +11,107 @@
 #
 # All configuration values have a default; values that are commented out
 # serve to show the default.
-from subprocess import call
-from sh.contrib import git
-import urllib.request
-from urllib.error import HTTPError
-import sys
-import re
 import os
+import re
+import shutil
 import subprocess
+import sys
+import tarfile
+import urllib.request
+import warnings
+from urllib.error import HTTPError
 
-git_branch = os.getenv('SPHINX_GIT_BRANCH', default=None)
+from sh.contrib import git
+
+CURR_PATH = os.path.dirname(os.path.abspath(os.path.expanduser(__file__)))
+PROJECT_ROOT = os.path.normpath(os.path.join(CURR_PATH, os.path.pardir))
+TMP_DIR = os.path.join(CURR_PATH, "tmp")
+DOX_DIR = "doxygen"
+
+
+def run_doxygen():
+    """Run the doxygen make command in the designated folder."""
+    curdir = os.path.normpath(os.path.abspath(os.path.curdir))
+    if os.path.exists(TMP_DIR):
+        print(f"Delete directory {TMP_DIR}")
+        shutil.rmtree(TMP_DIR)
+    else:
+        print(f"Create directory {TMP_DIR}")
+        os.mkdir(TMP_DIR)
+    try:
+        os.chdir(PROJECT_ROOT)
+        if not os.path.exists(DOX_DIR):
+            os.mkdir(DOX_DIR)
+        os.chdir(os.path.join(PROJECT_ROOT, DOX_DIR))
+        print(
+            "Build doxygen at {}".format(
+                os.path.join(PROJECT_ROOT, DOX_DIR, "doc_doxygen")
+            )
+        )
+        subprocess.check_call(["cmake", "..", "-DBUILD_C_DOC=ON", "-GNinja"])
+        subprocess.check_call(["ninja", "doc_doxygen"])
+
+        src = os.path.join(PROJECT_ROOT, DOX_DIR, "doc_doxygen", "html")
+        dest = os.path.join(TMP_DIR, "dev")
+        print(f"Copy directory {src} -> {dest}")
+        shutil.copytree(src, dest)
+    except OSError as e:
+        sys.stderr.write("doxygen execution failed: %s" % e)
+    finally:
+        os.chdir(curdir)
+
+
+def is_readthedocs_build():
+    if os.environ.get("READTHEDOCS", None) == "True":
+        return True
+    warnings.warn(
+        "Skipping Doxygen build... You won't have documentation for C/C++ functions. "
+        "Set environment variable READTHEDOCS=True if you want to build Doxygen. "
+        "(If you do opt in, make sure to install Doxygen, Graphviz, CMake, and C++ compiler "
+        "on your system.)"
+    )
+    return False
+
+
+if is_readthedocs_build():
+    run_doxygen()
+
+
+git_branch = os.getenv("SPHINX_GIT_BRANCH", default=None)
 if not git_branch:
     # If SPHINX_GIT_BRANCH environment variable is not given, run git
     # to determine branch name
     git_branch = [
-        re.sub(r'origin/', '', x.lstrip(' ')) for x in str(
-            git.branch('-r', '--contains', 'HEAD')).rstrip('\n').split('\n')
+        re.sub(r"origin/", "", x.lstrip(" "))
+        for x in str(git.branch("-r", "--contains", "HEAD")).rstrip("\n").split("\n")
     ]
-    git_branch = [x for x in git_branch if 'HEAD' not in x]
+    git_branch = [x for x in git_branch if "HEAD" not in x]
 else:
     git_branch = [git_branch]
-print('git_branch = {}'.format(git_branch[0]))
+print("git_branch = {}".format(git_branch[0]))
 
 try:
     filename, _ = urllib.request.urlretrieve(
-        'https://s3-us-west-2.amazonaws.com/xgboost-docs/{}.tar.bz2'.format(
-            git_branch[0]))
-    call(
-        'if [ -d tmp ]; then rm -rf tmp; fi; mkdir -p tmp/jvm; cd tmp/jvm; tar xvf {}'
-        .format(filename),
-        shell=True)
+        f"https://s3-us-west-2.amazonaws.com/xgboost-docs/{git_branch[0]}.tar.bz2"
+    )
+    if not os.path.exists(TMP_DIR):
+        print(f"Create directory {TMP_DIR}")
+        os.mkdir(TMP_DIR)
+    jvm_doc_dir = os.path.join(TMP_DIR, "jvm")
+    if os.path.exists(jvm_doc_dir):
+        print(f"Delete directory {jvm_doc_dir}")
+        shutil.rmtree(jvm_doc_dir)
+    print(f"Create directory {jvm_doc_dir}")
+    os.mkdir(jvm_doc_dir)
+
+    with tarfile.open(filename, "r:bz2") as t:
+        t.extractall(jvm_doc_dir)
 except HTTPError:
-    print('JVM doc not found. Skipping...')
-try:
-    filename, _ = urllib.request.urlretrieve(
-        'https://s3-us-west-2.amazonaws.com/xgboost-docs/doxygen/{}.tar.bz2'.
-        format(git_branch[0]))
-    call(
-        'mkdir -p tmp/dev; cd tmp/dev; tar xvf {}; mv doc_doxygen/html/* .; rm -rf doc_doxygen'
-        .format(filename),
-        shell=True)
-except HTTPError:
-    print('C API doc not found. Skipping...')
+    print("JVM doc not found. Skipping...")
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-CURR_PATH = os.path.dirname(os.path.abspath(os.path.expanduser(__file__)))
-PROJECT_ROOT = os.path.normpath(os.path.join(CURR_PATH, os.path.pardir))
 libpath = os.path.join(PROJECT_ROOT, "python-package/")
 sys.path.insert(0, libpath)
 sys.path.insert(0, CURR_PATH)
@@ -81,50 +134,56 @@ release = xgboost.__version__
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom ones
 extensions = [
-    'matplotlib.sphinxext.plot_directive',
-    'sphinx.ext.autodoc',
-    'sphinx.ext.napoleon',
-    'sphinx.ext.mathjax',
-    'sphinx.ext.intersphinx',
+    "matplotlib.sphinxext.plot_directive",
+    "sphinxcontrib.jquery",
+    "sphinx.ext.autodoc",
+    "sphinx.ext.napoleon",
+    "sphinx.ext.mathjax",
+    "sphinx.ext.intersphinx",
     "sphinx_gallery.gen_gallery",
-    'breathe',
-    'recommonmark'
+    "breathe",
+    "recommonmark",
 ]
 
 sphinx_gallery_conf = {
     # path to your example scripts
     "examples_dirs": ["../demo/guide-python", "../demo/dask", "../demo/aft_survival"],
     # path to where to save gallery generated output
-    "gallery_dirs": ["python/examples", "python/dask-examples", "python/survival-examples"],
+    "gallery_dirs": [
+        "python/examples",
+        "python/dask-examples",
+        "python/survival-examples",
+    ],
     "matplotlib_animations": True,
 }
 
 autodoc_typehints = "description"
 
-graphviz_output_format = 'png'
-plot_formats = [('svg', 300), ('png', 100), ('hires.png', 300)]
+graphviz_output_format = "png"
+plot_formats = [("svg", 300), ("png", 100), ("hires.png", 300)]
 plot_html_show_source_link = False
 plot_html_show_formats = False
 
 # Breathe extension variables
-DOX_DIR = "doxygen"
-breathe_projects = {
+breathe_projects = {}
+if is_readthedocs_build():
+    breathe_projects = {
         "xgboost": os.path.join(PROJECT_ROOT, DOX_DIR, "doc_doxygen/xml")
-}
+    }
 breathe_default_project = "xgboost"
 
 # Add any paths that contain templates here, relative to this directory.
-templates_path = ['_templates']
+templates_path = ["_templates"]
 
 # The suffix(es) of source filenames.
 # You can specify multiple suffix as a list of string:
-source_suffix = ['.rst', '.md']
+source_suffix = [".rst", ".md"]
 
 # The encoding of source files.
 # source_encoding = 'utf-8-sig'
 
 # The master toctree document.
-master_doc = 'index'
+master_doc = "index"
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
@@ -133,7 +192,7 @@ master_doc = 'index'
 # Usually you set "language" from the command line for these cases.
 language = "en"
 
-autoclass_content = 'both'
+autoclass_content = "both"
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
@@ -143,8 +202,10 @@ autoclass_content = 'both'
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
-exclude_patterns = ['_build']
-html_extra_path = ['./tmp']
+exclude_patterns = ["_build"]
+html_extra_path = []
+if is_readthedocs_build():
+    html_extra_path = [TMP_DIR]
 
 # The reST default role (used for this markup: `text`) to use for all
 # documents.
@@ -162,7 +223,7 @@ html_extra_path = ['./tmp']
 # show_authors = False
 
 # The name of the Pygments (syntax highlighting) style to use.
-pygments_style = 'sphinx'
+pygments_style = "sphinx"
 
 # A list of ignored prefixes for module index sorting.
 # modindex_common_prefix = []
@@ -185,27 +246,24 @@ html_logo = "https://raw.githubusercontent.com/dmlc/dmlc.github.io/master/img/lo
 
 html_css_files = ["css/custom.css"]
 
-html_sidebars = {
-  '**': ['logo-text.html', 'globaltoc.html', 'searchbox.html']
-}
+html_sidebars = {"**": ["logo-text.html", "globaltoc.html", "searchbox.html"]}
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['_static']
+html_static_path = ["_static"]
 
 # Output file base name for HTML help builder.
-htmlhelp_basename = project + 'doc'
+htmlhelp_basename = project + "doc"
 
 # -- Options for LaTeX output ---------------------------------------------
-latex_elements = {
-}
+latex_elements = {}
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title,
 #  author, documentclass [howto, manual, or own class]).
 latex_documents = [
-  (master_doc, '%s.tex' % project, project, author, 'manual'),
+    (master_doc, "%s.tex" % project, project, author, "manual"),
 ]
 
 intersphinx_mapping = {
@@ -220,30 +278,5 @@ intersphinx_mapping = {
 }
 
 
-# hook for doxygen
-def run_doxygen():
-    """Run the doxygen make command in the designated folder."""
-    curdir = os.path.normpath(os.path.abspath(os.path.curdir))
-    try:
-        os.chdir(PROJECT_ROOT)
-        if not os.path.exists(DOX_DIR):
-            os.mkdir(DOX_DIR)
-        os.chdir(os.path.join(PROJECT_ROOT, DOX_DIR))
-        subprocess.check_call(["cmake", "..", "-DBUILD_C_DOC=ON", "-GNinja"])
-        subprocess.check_call(["ninja", "doc_doxygen"])
-    except OSError as e:
-        sys.stderr.write("doxygen execution failed: %s" % e)
-    finally:
-        os.chdir(curdir)
-
-
-def generate_doxygen_xml(app):
-    """Run the doxygen make commands if we're on the ReadTheDocs server"""
-    read_the_docs_build = os.environ.get('READTHEDOCS', None) == 'True'
-    if read_the_docs_build:
-        run_doxygen()
-
-
 def setup(app):
-    app.add_css_file('custom.css')
-    app.connect("builder-inited", generate_doxygen_xml)
+    app.add_css_file("custom.css")