[cmake] Manage dependencies in a seperate deps subdirectory

CMakeLists.txt

@@ -52,6 +52,10 @@ if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT OR (NOT IS_ABSOLUTE ${CMAKE_INSTA
 endif()
 message(STATUS "-------- CMAKE_INSTALL_PREFIX: ${CMAKE_INSTALL_PREFIX} --------")
 
+# ############
+# Dependencies
+add_subdirectory(deps)
+
 # ############
 # Options
 

deps/CMakeLists.txt

@@ -0,0 +1,18 @@
+# Each dependency should be either
+#  * a cmake subproject in this directory
+#  * found in the system using find_package
+# Provide either a download.sh script to get all sources
+# or use e.g. git subtree/submodule or softlinks
+
+# Add all subdirectories as CMake Sub-Projects
+file(GLOB allfiles CONFIGURE_DEPENDS *)
+foreach(file ${allfiles})
+  if(IS_DIRECTORY ${file})
+    add_subdirectory(${file})
+  endif()
+endforeach()
+
+# -- googletest --
+if(NOT TARGET gtest)
+  find_package(GTest REQUIRED)
+endif()

deps/download.sh

@@ -0,0 +1 @@
+git clone https://github.com/google/googletest --branch v1.10.x --depth 1

doc/install.rst

@@ -19,6 +19,13 @@ Installation steps
 
      $ git clone https://github.com/TRIQS/app4triqs app4triqs.src
 
+#. Make sure that all additional dependencies are installed on your system and available in your environment.
+   Alternatively build the dependencies from source instead with::
+
+     $ (cd deps && ./download.sh)
+
+   In this case they will be installed together with your application.
+
 #. Create and move to a new directory where you will compile the code::
 
      $ mkdir app4triqs.build && cd app4triqs.build

test/c++/CMakeLists.txt

@@ -1,7 +1,3 @@
-# Build googletest
-set(PYTHON_EXECUTABLE ${TRIQS_PYTHON_EXECUTABLE})
-add_subdirectory(gtest EXCLUDE_FROM_ALL)
-
 # Copy h5 files to binary dir
 file(GLOB_RECURSE all_h5_ref_files RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} *.ref.h5)
 foreach(file ${all_h5_ref_files})