From b80286ef813dbdd69bc9d0c5bd780b3a0befbc9f Mon Sep 17 00:00:00 2001
From: Lars Melchior <TheLartians@users.noreply.github.com>
Date: Mon, 15 Feb 2021 13:04:32 +0100
Subject: [PATCH] add dependencies using EXCLUDE_FROM_ALL flag

---
 cmake/CPM.cmake | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/cmake/CPM.cmake b/cmake/CPM.cmake
index 6315d31..799317c 100644
--- a/cmake/CPM.cmake
+++ b/cmake/CPM.cmake
@@ -387,7 +387,7 @@ function(CPMAddPackage)
       set(${CPM_ARGS_NAME}_ADDED YES)
       set(${CPM_ARGS_NAME}_SOURCE_DIR ${download_directory})
       if(NOT CPM_ARGS_DOWNLOAD_ONLY AND EXISTS ${download_directory}/CMakeLists.txt)
-        add_subdirectory(${download_directory} ${${CPM_ARGS_NAME}_BINARY_DIR})
+        add_subdirectory(${download_directory} ${${CPM_ARGS_NAME}_BINARY_DIR} EXCLUDE_FROM_ALL)
       endif()
       set(CPM_SKIP_FETCH TRUE)
       set(PACKAGE_INFO "${PACKAGE_INFO} at ${download_directory}")
@@ -557,16 +557,19 @@ function(cpm_fetch_package PACKAGE DOWNLOAD_ONLY)
     return()
   endif()
 
-  if(DOWNLOAD_ONLY)
-    FetchContent_GetProperties(${PACKAGE})
-    if(NOT ${PACKAGE}_POPULATED)
-      FetchContent_Populate(${PACKAGE})
+  FetchContent_GetProperties(${PACKAGE})
+  string(TOLOWER "${PACKAGE}" lower_case_name)
+
+  if(NOT ${lower_case_name}_POPULATED)
+    FetchContent_Populate(${PACKAGE})
+    if(EXISTS ${${lower_case_name}_SOURCE_DIR}/CMakeLists.txt)
+      set(CPM_OLD_INDENT "${CPM_INDENT}")
+      set(CPM_INDENT "${CPM_INDENT} ${PACKAGE}:")
+      add_subdirectory(
+        ${${lower_case_name}_SOURCE_DIR} ${${lower_case_name}_BINARY_DIR} EXCLUDE_FROM_ALL
+      )
+      set(CPM_INDENT "${CPM_OLD_INDENT}")
     endif()
-  else()
-    set(CPM_OLD_INDENT "${CPM_INDENT}")
-    set(CPM_INDENT "${CPM_INDENT} ${PACKAGE}:")
-    FetchContent_MakeAvailable(${PACKAGE})
-    set(CPM_INDENT "${CPM_OLD_INDENT}")
   endif()
 endfunction()