From 806b62903500a1aa1d45edf074b54a41db5af538 Mon Sep 17 00:00:00 2001
From: Davis King <davis@dlib.net>
Date: Thu, 23 Mar 2023 20:07:48 -0400
Subject: [PATCH] Make everything work in cmake 3.8

---
 dlib/test/CMakeLists.txt | 12 ++++++++++--
 examples/CMakeLists.txt  |  8 ++++++--
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/dlib/test/CMakeLists.txt b/dlib/test/CMakeLists.txt
index 249b38164..a20640a85 100644
--- a/dlib/test/CMakeLists.txt
+++ b/dlib/test/CMakeLists.txt
@@ -184,7 +184,11 @@ if (CMAKE_COMPILER_IS_GNUCXX)
       # definitely heap allocated.
       add_compile_options(-Wno-free-nonheap-object)
    endif()
-   target_link_options(${target_name} PRIVATE $<$<CONFIG:RELEASE>:-s>)
+
+   if(${CMAKE_VERSION} VERSION_GREATER "3.8.0") 
+      # strip debug symbols to make the binary smaller
+      target_link_options(${target_name} PRIVATE $<$<CONFIG:RELEASE>:-s>)
+   endif()
 
 elseif (MSVC)
    # Treat warnings as errors.
@@ -194,7 +198,11 @@ else() # basically Clang
    add_compile_options(-W -Werror)
    # This is for the comment in face_detection_ex.cpp that says "faces/*.jpg"
    add_compile_options(-Wno-comment)
-   target_link_options(${target_name} PRIVATE $<$<CONFIG:RELEASE>:-s>)
+
+   if(${CMAKE_VERSION} VERSION_GREATER "3.8.0") 
+      # strip debug symbols to make the binary smaller
+      target_link_options(${target_name} PRIVATE $<$<CONFIG:RELEASE>:-s>)
+   endif()
 endif()
 
 
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index 579e87a74..e8f720656 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -106,8 +106,12 @@ target_link_libraries(assignment_learning_ex dlib::dlib)
 macro(add_example name)
    add_executable(${name} ${name}.cpp)
    target_link_libraries(${name} dlib::dlib )
-   # And strip symbols to make your binary smaller if you like.  Certainly not required though.
-   target_link_options(${name} PRIVATE $<$<CONFIG:RELEASE>:-s>)
+
+   if(${CMAKE_VERSION} VERSION_GREATER "3.8.0") 
+   # And strip symbols to make your binary smaller if you like.  Certainly not
+   # required though.
+       target_link_options(${name} PRIVATE $<$<CONFIG:RELEASE>:-s>)
+   endif()
 endmacro()
 
 # if an example requires GUI, call this macro to check DLIB_NO_GUI_SUPPORT to include or exclude