From fad34678f1fd4fb8b562be9d4d3072efe26eeb9c Mon Sep 17 00:00:00 2001
From: jkriege2 <jan@jkrieger.de>
Date: Sun, 14 Jan 2024 16:55:06 +0100
Subject: [PATCH] NEW: disallow in-source builds

---
 CMakeLists.txt                           |  3 +++
 cmake/jkqtplotter_noInsourceBuilds.cmake | 11 +++++++++++
 2 files changed, 14 insertions(+)
 create mode 100644 cmake/jkqtplotter_noInsourceBuilds.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2cd941c1c5..01b1f82c11 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,6 +24,9 @@ list(APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake)
 # Find includes in the build directories
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
+# error message when user tries to make in-source build!
+include(jkqtplotter_noInsourceBuilds)
+
 # Common Includes for JKQtPlotter
 include(jkqtplotter_common_include)
 
diff --git a/cmake/jkqtplotter_noInsourceBuilds.cmake b/cmake/jkqtplotter_noInsourceBuilds.cmake
new file mode 100644
index 0000000000..8cd379a8c0
--- /dev/null
+++ b/cmake/jkqtplotter_noInsourceBuilds.cmake
@@ -0,0 +1,11 @@
+if(PROJECT_SOURCE_DIR STREQUAL PROJECT_BINARY_DIR)
+    message(FATAL_ERROR
+        "\n"
+        "In-source builds are not allowed.\n"
+        "Instead, provide a path to build tree like so:\n"
+        "cmake -B <destination>\n"
+        "\n"
+        "To remove files you accidentally created execute:\n"
+        "rm -rf CMakeFiles CMakeCache.txt\n"
+    )
+endif()