CMake: Set default visibility to hidden and dllexport on windows

CMakeLists.txt

@@ -61,6 +61,16 @@ if (ENABLE_SANITIZERS)
         )
 endif()
 
+option(ENABLE_PUBLIC_SYMBOLS "Export library symbols." On)
+if (ENABLE_PUBLIC_SYMBOLS)
+    list(APPEND custom_compiler_flags -fvisibility=hidden)
+    add_definitions(-DCJSON_EXPORT_SYMBOLS -DCJSON_API_VISIBILITY)
+endif()
+option(ENABLE_HIDDEN_SYMBOLS "Hide library symbols." Off)
+if (ENABLE_HIDDEN_SYMBOLS)
+    add_definitions(-DCJSON_HIDE_SYMBOLS -UCJSON_API_VISIBILITY)
+endif()
+
 # apply custom compiler flags
 foreach(compiler_flag ${custom_compiler_flags})
     #remove problematic characters

cJSON.c

@@ -23,6 +23,7 @@
 /* cJSON */
 /* JSON parser in C. */
 
+#pragma GCC visibility push(default)
 #include <string.h>
 #include <stdio.h>
 #include <math.h>
@@ -30,6 +31,8 @@
 #include <float.h>
 #include <limits.h>
 #include <ctype.h>
+#pragma GCC visibility pop
+
 #include "cJSON.h"
 
 /* define our own boolean type */

tests/CMakeLists.txt

@@ -7,6 +7,11 @@ if(ENABLE_CJSON_TEST)
     if (werror_found)
         target_compile_options(unity PRIVATE "-Wno-error")
     endif()
+    # Disable -fvisibility=hidden for Unity
+    list(FIND custom_compiler_flags "-fvisibility=hidden" visibility_found)
+    if (visibility_found)
+        target_compile_options(unity PRIVATE "-fvisibility=default")
+    endif()
 
     #copy test files
     file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/inputs")