Changes to allow building as a static library and to set RPATH (#182)

* Changes to allow building as a static library and to set RPATH

* Avoid redefinition warning on MacOS

Author: perdrix52

.gitignore

@@ -4,3 +4,5 @@
 Makefile
 moc_*.cpp
 *.pro.user*
+# CMake build directory
+build/

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.16)
+cmake_minimum_required(VERSION 3.21)
 
 project(SmtpMime
   VERSION 2.0
@@ -13,22 +13,36 @@ set(CMAKE_AUTOUIC OFF)
 set(CMAKE_AUTOMOC ON)
 set(CMAKE_AUTORCC OFF)
 
-find_package(QT NAMES Qt6 COMPONENTS Core Network REQUIRED)
-find_package(Qt${QT_VERSION_MAJOR} COMPONENTS Core Network REQUIRED)
+find_package(QT NAMES Qt6 COMPONENTS Core Network Test REQUIRED)
+find_package(Qt${QT_VERSION_MAJOR} COMPONENTS Core Network Test REQUIRED)
 
 set(LIBRARY_TARGET_NAME ${PROJECT_NAME})
 
-message(USING Qt${QT_VERSION_MAJOR})
+message("Using Qt" ${QT_VERSION_MAJOR})
+
+#
+# Allow -DBUILD_SHARED_LIBS to control the library type built by qt_add_library
+#
+qt_policy(SET QTP0003 NEW)
+
+#
+# Set the default for BUILD_SHARED_LIBS to ON, but allow command line
+# to override using -DBUILD_SHARED_LIBS=OFF
+#
+option(BUILD_SHARED_LIBS "Build as a shared library" ON)
 
-set(CMAKE_SKIP_BUILD_RPATH FALSE)
-#set(CMAKE_BUILD_WITH_INSTALL_RPATH TRUE)   # note: this breaks the demos
 set(CMAKE_INSTALL_RPATH $ORIGIN)
 
+if(BUILD_SHARED_LIBS)
+  add_compile_options(-DBUILD_SHARED_LIBS)
+endif()
+
 add_subdirectory(src)
 
 if (BUILD_TESTS)
   add_subdirectory(test)
 endif()
+
 if (BUILD_DEMOS)
   add_subdirectory(demos)
 endif()

src/CMakeLists.txt

@@ -1,6 +1,6 @@
 add_compile_options(-DSMTP_MIME_LIBRARY)
 
-qt_add_library(${LIBRARY_TARGET_NAME} SHARED
+qt_add_library(${LIBRARY_TARGET_NAME}
     emailaddress.cpp
     mimeattachment.cpp
     mimebytearrayattachment.cpp
@@ -91,3 +91,4 @@ install(TARGETS ${LIBRARY_TARGET_NAME}
     LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
     PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/smtpmime
 )
+

src/smtpmime_global.h

@@ -1,10 +1,14 @@
 #ifndef SMTPMIME_GLOBAL_H
 #define SMTPMIME_GLOBAL_H
 
-#ifdef SMTP_MIME_LIBRARY
-#define SMTP_MIME_EXPORT Q_DECL_EXPORT
+#if defined(BUILD_SHARED_LIBS)
+#  ifdef SMTP_MIME_LIBRARY
+#    define SMTP_MIME_EXPORT Q_DECL_EXPORT
+#  else
+#    define SMTP_MIME_EXPORT Q_DECL_IMPORT
+#  endif
 #else
-#define SMTP_MIME_EXPORT Q_DECL_IMPORT
+#  define SMTP_MIME_EXPORT
 #endif
 
 #endif // SMTPMIME_GLOBAL_H