From 638db5ca5e47066b0b9ac297bdcfcae69ccd0276 Mon Sep 17 00:00:00 2001
From: Vitaly Zaitsev <vitaly@easycoding.org>
Date: Tue, 7 Jul 2020 16:35:01 +0200
Subject: [PATCH] Use Cmake to find Python and Sphinx-doc.

Signed-off-by: Vitaly Zaitsev <vitaly@easycoding.org>
---
 doc/CMakeLists.txt | 9 +++++++--
 doc/build.py       | 6 +++---
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
index 108aa71e..8e5e8a83 100644
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -4,10 +4,15 @@ if (NOT DOXYGEN)
   return ()
 endif ()
 
+find_package(PythonInterp QUIET REQUIRED)
+find_program(SPHINX_EXECUTABLE NAMES sphinx-build sphinx-build-3)
+
 add_custom_target(doc
-  COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/build.py ${FMT_VERSION}
+  COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/build.py
+                               ${SPHINX_EXECUTABLE} ${FMT_VERSION}
   SOURCES api.rst syntax.rst usage.rst build.py conf.py _templates/layout.html)
 
+include(GNUInstallDirs)
 install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/html/
-        DESTINATION share/doc/fmt OPTIONAL
+        DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/doc/fmt OPTIONAL
         PATTERN ".doctrees" EXCLUDE)
diff --git a/doc/build.py b/doc/build.py
index 25d7885a..385205d9 100755
--- a/doc/build.py
+++ b/doc/build.py
@@ -59,7 +59,7 @@ def create_build_env(dirname='virtualenv'):
               '129222318f7c8f865d2631e7da7b033567e7f56a',
               min_version='4.2.0')
 
-def build_docs(version='dev', **kwargs):
+def build_docs(sphinx_executable='sphinx-build', version='dev', **kwargs):
   doc_dir = kwargs.get('doc_dir', os.path.dirname(os.path.realpath(__file__)))
   work_dir = kwargs.get('work_dir', '.')
   include_dir = kwargs.get(
@@ -101,7 +101,7 @@ def build_docs(version='dev', **kwargs):
     raise CalledProcessError(p.returncode, cmd)
   html_dir = os.path.join(work_dir, 'html')
   main_versions = reversed(versions[-3:])
-  check_call(['sphinx-build',
+  check_call([sphinx_executable,
               '-Dbreathe_projects.format=' + os.path.abspath(doxyxml_dir),
               '-Dversion=' + version, '-Drelease=' + version,
               '-Aversion=' + version, '-Aversions=' + ','.join(main_versions),
@@ -121,4 +121,4 @@ def build_docs(version='dev', **kwargs):
 
 if __name__ == '__main__':
   create_build_env()
-  build_docs(sys.argv[1])
+  build_docs(sys.argv[1], sys.argv[2])