(Try to) use dll import/export for variable on MSVC

CURA-13049

Author: wawanbreton

CMakeLists.txt

@@ -86,6 +86,7 @@ target_link_libraries(cura-formulae-engine
 target_compile_definitions(cura-formulae-engine
         INTERFACE
         CURA_FORMULA_VERSION_VERSION="${CURA_FORMULA_VERSION_VERSION}"
+        CURA_FORMULAE_ENGINE_EXPORT=1
 )
 
 target_include_directories(

include/cura-formulae-engine/config.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#ifdef _WIN32
+#    ifdef CURA_FORMULAE_ENGINE_EXPORT
+#        define CURA_FORMULAE_ENGINE_API __declspec(dllexport)
+#    else
+#        define CURA_FORMULAE_ENGINE_API __declspec(dllimport)
+#    endif
+#else
+#    define CURA_FORMULAE_ENGINE_API
+#endif

include/cura-formulae-engine/env/env.h

@@ -1,13 +1,14 @@
 #pragma once
 
 #include "cura-formulae-engine/ast/ast.h"
+#include "cura-formulae-engine/config.h"
 
 namespace CuraFormulaeEngine::env
 {
 
 /**
  * @brief The standard environment.
  */
-extern const EnvironmentMap std_env;
+CURA_FORMULAE_ENGINE_API extern const EnvironmentMap std_env;
 
 } // namespace CuraFormulaeEngine::env

src/env/env.cpp

@@ -35,7 +35,7 @@ namespace CuraFormulaeEngine::env
 /**
  * @brief The standard environment.
  */
-const EnvironmentMap std_env = []()
+CURA_FORMULAE_ENGINE_API const EnvironmentMap std_env = []()
 {
     EnvironmentMap env;