fix build with Doxygen 1.10 and later

Documentation/doc/CMakeLists.txt

@@ -24,6 +24,8 @@ else()
   set(CGAL_ROOT "${CMAKE_SOURCE_DIR}")
 endif()
 
+cmake_minimum_required(VERSION 3.18..3.29) # for list(SORT ... COMPARE NATURAL)
+
 find_package(Doxygen REQUIRED)
 find_package(Python3 REQUIRED COMPONENTS Interpreter)
 
@@ -32,7 +34,7 @@ if (NOT Python3_EXECUTABLE)
   return()
 endif()
 
-message(STATUS  ${Python3_EXECUTABLE})
+message(VERBOSE "Using Python version ${Python3_VERSION}: ${Python3_EXECUTABLE}")
 
 if(NOT DOXYGEN_FOUND)
   message(WARNING "Cannot build the documentation without Doxygen!")
@@ -275,7 +277,7 @@ set(CGAL_DOC_DXY_DIR "${CMAKE_BINARY_DIR}/doc_dxy")
 file(MAKE_DIRECTORY "${CGAL_DOC_DXY_DIR}")
 
 #Setting the resource directory depending on the version of doxygen
-set(CGAL_DOC_RESOURCE_DIR_DEFAULT "${CMAKE_CURRENT_LIST_DIR}/resources/1.10.0")
+set(CGAL_DOC_RESOURCE_PREFIX_DIR "${CMAKE_CURRENT_LIST_DIR}/resources")
 
 #  first look if resources for the specific doxygen version is available, fallback
 #  on the default otherwise
@@ -283,12 +285,46 @@ set(CGAL_DOC_RESOURCE_DIR_DEFAULT "${CMAKE_CURRENT_LIST_DIR}/resources/1.10.0")
 #select only the version number (not the commit hash)
 string(REPLACE " " ";" DOXYGEN_VERSION ${DOXYGEN_VERSION})
 list(GET DOXYGEN_VERSION 0 DOXYGEN_VERSION)
+message(VERBOSE "Doxygen version ${DOXYGEN_VERSION}: ${DOXYGEN_EXECUTABLE}")
 
-if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/resources/${DOXYGEN_VERSION}")
-  set(CGAL_DOC_RESOURCE_DIR
-      "${CMAKE_CURRENT_LIST_DIR}/resources/${DOXYGEN_VERSION}")
+# The Doxygen version is search in that sorted list (to find the index for which the version is less or equal)
+set(CGAL_DOXYGEN_RESOURCES_VERSIONS 1.8.13 1.9.6 1.10.0)
+list(SORT CGAL_DOXYGEN_RESOURCES_VERSIONS COMPARE NATURAL)
+
+# The GLOB is here to check that the list in CGAL_DOXYGEN_RESOURCES_VERSIONS is correct.
+# CGAL_DOXYGEN_RESOURCES_DIRS is also used below.
+file(GLOB CGAL_DOXYGEN_RESOURCES_DIRS
+    RELATIVE "${CGAL_DOC_RESOURCE_PREFIX_DIR}"
+    "${CGAL_DOC_RESOURCE_PREFIX_DIR}/*")
+list(SORT CGAL_DOXYGEN_RESOURCES_DIRS COMPARE NATURAL)
+
+if(NOT CGAL_DOXYGEN_RESOURCES_DIRS STREQUAL CGAL_DOXYGEN_RESOURCES_VERSIONS)
+  message(FATAL "The directories in ${CGAL_DOC_RESOURCE_PREFIX_DIR} do not match the
+expected versions: [${CGAL_DOXYGEN_RESOURCES_VERSIONS}] vs [${CGAL_DOXYGEN_RESOURCES_DIRS}]")
+endif()
+
+function(CGAL_insert_in_sorted_list list_name value)
+  set(list ${${list_name}})
+  if(NOT value IN_LIST list)
+    list(APPEND list "${value}")
+    list(SORT list COMPARE NATURAL)
+  endif()
+  set(${list_name} ${list} PARENT_SCOPE)
+endfunction()
+
+if(DOXYGEN_VERSION IN_LIST CGAL_DOXYGEN_RESOURCES_VERSIONS)
+  list(FIND CGAL_DOXYGEN_RESOURCES_VERSIONS "${DOXYGEN_VERSION}" DOXYGEN_VERSION_INDEX)
 else()
-  set(CGAL_DOC_RESOURCE_DIR "${CGAL_DOC_RESOURCE_DIR_DEFAULT}")
+  CGAL_insert_in_sorted_list(CGAL_DOXYGEN_RESOURCES_VERSIONS ${DOXYGEN_VERSION})
+  list(FIND CGAL_DOXYGEN_RESOURCES_VERSIONS ${DOXYGEN_VERSION} DOXYGEN_VERSION_INDEX)
+  math(EXPR DOXYGEN_VERSION_INDEX "${DOXYGEN_VERSION_INDEX} - 1")
+endif()
+list(GET CGAL_DOXYGEN_RESOURCES_DIRS "${DOXYGEN_VERSION_INDEX}" CGAL_DOC_RESOURCE_DIR)
+set(CGAL_DOC_RESOURCE_DIR "${CGAL_DOC_RESOURCE_PREFIX_DIR}/${CGAL_DOC_RESOURCE_DIR}")
+if(NOT EXISTS "${CGAL_DOC_RESOURCE_DIR}")
+  message(FATAL_ERROR "Doxygen resources for version ${DOXYGEN_VERSION} not found")
+else()
+  message(VERBOSE "Using Doxygen resources from ${CGAL_DOC_RESOURCE_DIR}")
 endif()
 
 set(CGAL_DOC_BIBLIO_DIR "${CMAKE_CURRENT_LIST_DIR}/biblio")

Documentation/doc/Documentation/Developer_manual/cmakelist_script.txt

@@ -35,6 +35,6 @@ These options should suffice to create a `CMakeLists.txt` script
 for most directories containing programs. However, in some special
 cases, it might still be required to create the script manually, for
 instance, if some source files/executables need a different linking than
-other source files. The Section \subpage devman_create_and_use_a_cmakelist provides more details.
+other source files. The Section \ref devman_create_and_use_a_cmakelist provides more details.
 
 */

Documentation/doc/Documentation/Developer_manual/developer_manual.txt

@@ -23,4 +23,5 @@ The developer manual is primarily aimed at \cgal developers, but may also be int
 - \subpage devman_info
 - \subpage devman_create_cgal_CMakeLists
 - \subpage deprecated
+- \subpage Doxygen_for_CGAL
 */

Documentation/doc/Documentation/Doxygen_for_CGAL.md

@@ -1,4 +1,4 @@
-# Doxygen for CGAL #
+\page Doxygen_for_CGAL Doxygen for CGAL
 
 This is the documentation of doxygen hacks that are applied to make
 the output of Doxygen more suitable to CGAL. It explains the general
@@ -14,17 +14,17 @@ hacks that create what you see.
 ### Package Overview ###
 
 The package overview is build by having a special command that is
-filtered by the python script pkglist_filter.py.
+filtered by the python script `pkglist_filter.py`.
 
-A command has to be of the form \package_listing{PKG_NAME}, where
-PKG_NAME cannot contain a closing }.
+A command has to be of the form `\package_listing{PKG_NAME}`, where
+`PKG_NAME` cannot contain a closing `}`.
 
 The command is replaced by the text between the two delimiters
-PkgDescBegin and PkgDescEnd in the file ../PKG_NAME/doc/PKG_NAME/PackageDescription.txt
+`cgalPkgDescriptionBegin` and `cgalPkgDescriptionEnd` in the file `../PKG_NAME/doc/PKG_NAME/PackageDescription.txt`
 
-If PKG_NAME is of the form A/B the selected file is
-../A/doc/B/PackageDescription.txt. This is to support packages like
-TDS_2, which don't reside in their own packages in the SCM.
+If `PKG_NAME` is of the form `A/B` the selected file is
+`../A/doc/B/PackageDescription.txt`. This is to support packages like
+`TDS_2`, which don't reside in their own packages in the SCM.
 
 ### Footnotes ###
 
@@ -50,13 +50,13 @@ LaTex.
 This hack fiddles with the internal structures and functions of the
 treeview to remove the unnecessary intermediate top-level module part.
 
-It assigns the first element of the module array (found in module.js)
+It assigns the first element of the module array (found in `module.js`)
 to the Reference Manual entry. This makes the tree view link go to
 that group directly instead of the intermediate link. It also removes
 one level of nesting.
 
 Unfortunately this changes the overall tree structure. To adjust for
-that we hijack the gotoNode function of navtree.js and *augment* it
+that we hijack the `gotoNode` function of `navtree.js` and *augment* it
 with an additional check for the specific tree level we borked and
 redirect it.
 

Documentation/doc/scripts/pkglist_filter.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import codecs
 import re
@@ -28,16 +28,10 @@ def main(argv):
             for l in pkgdesc:
                 do_print = do_print or re.match(".*cgalPkgDescriptionBegin.*", l)
                 if(do_print):
-                  if hasattr(sys.stdout, 'buffer'):
-                    sys.stdout.buffer.write(l.encode('utf-8')) #python3
-                  else:
-                    sys.stdout.write(l.encode('utf-8')) #python2
+                  sys.stdout.buffer.write(l.encode('utf-8'))
                 do_print = do_print and (not re.match(".*cgalPkgDescriptionEnd.*", l))
         else:
-          if hasattr(sys.stdout, 'buffer'):
-            sys.stdout.buffer.write(line.encode('utf-8')) #python3
-          else:
-            sys.stdout.write(line.encode('utf-8')) #python2
+          sys.stdout.buffer.write(line.encode('utf-8'))
 
 if __name__ == "__main__":
     main(sys.argv)