Added a link time check that you aren't mixing headers from one version of dlib

with binaries from a different dlib version.

dlib/CMakeLists.txt

@@ -744,6 +744,13 @@ if (NOT TARGET dlib)
       # the code in dlib/threads_kernel_shared.cpp to emit a linker error for users who
       # don't use the configured config.h file generated by cmake.
       target_compile_options(dlib PRIVATE -DDLIB__CMAKE_GENERATED_A_CONFIG_H_FILE)
+
+      # Do this so that dlib/config.h can record the version of dlib it's configured with
+      # and ultimately issue a linker error to people who try to use a binary dlib that is
+      # the wrong version.
+      set(DLIB_CHECK_FOR_VERSION_MISSMATCH 
+         DLIB_VERSION_CHECK_${CPACK_PACKAGE_VERSION_MAJOR}_${CPACK_PACKAGE_VERSION_MINOR}_${CPACK_PACKAGE_VERSION_PATCH})
+      target_compile_options(dlib PRIVATE "-DDLIB_CHECK_FOR_VERSION_MISSMATCH=${DLIB_CHECK_FOR_VERSION_MISSMATCH}")
    endif()
 
 

dlib/config.h.in

@@ -27,3 +27,8 @@
 #cmakedefine DLIB_USE_LAPACK
 #cmakedefine DLIB_USE_CUDA
 #cmakedefine DLIB_USE_MKL_FFT
+
+// This variable allows dlib/test_for_odr_violations.h to catch people who mistakenly use
+// headers from one version of dlib with a compiled dlib binary from a different dlib version.
+#cmakedefine DLIB_CHECK_FOR_VERSION_MISSMATCH @DLIB_CHECK_FOR_VERSION_MISSMATCH@
+

dlib/test_for_odr_violations.cpp

@@ -31,6 +31,15 @@ extern "C"
 #if defined(DLIB_NOT_CONFIGURED) && !defined(DLIB__CMAKE_GENERATED_A_CONFIG_H_FILE)
     int USER_ERROR__inconsistent_build_configuration__see_dlib_faq_2;
 #endif
+
+
+
+
+
+#ifdef DLIB_CHECK_FOR_VERSION_MISSMATCH
+    int DLIB_CHECK_FOR_VERSION_MISSMATCH;
+#endif
+
 }
 
 

dlib/test_for_odr_violations.h

@@ -41,15 +41,20 @@ extern "C"
 #if defined(DLIB_NOT_CONFIGURED) && !defined(DLIB__CMAKE_GENERATED_A_CONFIG_H_FILE)
     extern int USER_ERROR__inconsistent_build_configuration__see_dlib_faq_2;
     inline int dlib_check_consistent_config_h_usage() { USER_ERROR__inconsistent_build_configuration__see_dlib_faq_2 = 0; return 0; }
-#else
-    inline int dlib_check_consistent_config_h_usage() { return 0; }
-#endif
     const int DLIB_NO_WARN_UNUSED dlib_check_not_configured_helper_variable = dlib_check_consistent_config_h_usage();
+#endif
 
-}
 
 
+// Cause the user to get a linker error if they try to use header files from one version of
+// dlib with the compiled binary from a different version of dlib.
+#ifdef DLIB_CHECK_FOR_VERSION_MISSMATCH
+    extern int DLIB_CHECK_FOR_VERSION_MISSMATCH;
+    inline int dlib_check_for_dlib_version_missmatch() { DLIB_CHECK_FOR_VERSION_MISSMATCH = 0; return 0; }
+    const int DLIB_NO_WARN_UNUSED dlib_check_for_version_missmatch = dlib_check_for_dlib_version_missmatch();
+#endif
 
+}
 
 #endif // DLIB_TEST_FOR_ODR_VIOLATIONS_H_