support dynamic library too

generate export header needed and install it

CMakeLists.txt

@@ -20,7 +20,7 @@ endif()
 
 # ---- Project settings ----
 
-option(BUILD_SHARED_LIBS "Create shared libraries if ON" OFF)
+option(BUILD_SHARED_LIBS "Create shared libraries if ON" YES)
 
 if(NOT DEFINED CMAKE_CXX_STANDARD)
   set(CMAKE_CXX_STANDARD 20)
@@ -28,6 +28,10 @@ if(NOT DEFINED CMAKE_CXX_STANDARD)
   set(CMAKE_CXX_EXTENSIONS NO)
 endif()
 
+# Set default visibility to hidden for all targets
+set(CMAKE_CXX_VISIBILITY_PRESET hidden)
+set(CMAKE_VISIBILITY_INLINES_HIDDEN YES)
+
 # ---- Add dependencies via CPM ----
 # see https://github.com/cpm-cmake/CPM.cmake for more info
 
@@ -78,9 +82,10 @@ endif()
 target_link_libraries(Greeter PRIVATE $<BUILD_INTERFACE:fmt::fmt-header-only>)
 # OR: target_link_libraries(Greeter PUBLIC fmt::fmt)
 
+set(INCLUDE_INSTALL_DIR include/${PROJECT_NAME}-${PROJECT_VERSION})
 target_include_directories(
-  Greeter PUBLIC $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
+  Greeter BEFORE PUBLIC $<BUILD_INTERFACE: ${PROJECT_SOURCE_DIR}/include>
-                 $<INSTALL_INTERFACE:include/${PROJECT_NAME}-${PROJECT_VERSION}>
+                        $<INSTALL_INTERFACE:${INCLUDE_INSTALL_DIR}>
 )
 
 # ---- Create an installable target ----
@@ -89,6 +94,14 @@ target_include_directories(
 # the location where the project's version header will be placed should match the project's regular
 # header paths
 string(TOLOWER ${PROJECT_NAME}/version.h VERSION_HEADER_LOCATION)
+string(TOLOWER ${PROJECT_NAME}/greeter_export.h EXPORT_HEADER_LOCATION)
+
+# TODO: should be done in packageProject()
+include(GenerateExportHeader)
+generate_export_header(
+  ${PROJECT_NAME} EXPORT_FILE_NAME PackageProjectInclude/${EXPORT_HEADER_LOCATION}
+)
+# Note: the export header will be installed while installing the version header! CK
 
 packageProject(
   NAME ${PROJECT_NAME}
@@ -96,8 +109,8 @@ packageProject(
   NAMESPACE ${PROJECT_NAME}
   BINARY_DIR ${PROJECT_BINARY_DIR}
   INCLUDE_DIR ${PROJECT_SOURCE_DIR}/include
-  INCLUDE_DESTINATION include/${PROJECT_NAME}-${PROJECT_VERSION}
+  INCLUDE_DESTINATION ${INCLUDE_INSTALL_DIR}
   VERSION_HEADER "${VERSION_HEADER_LOCATION}"
   COMPATIBILITY SameMajorVersion
-  # NOTE: not needed DEPENDENCIES "fmt 7.1.3"
+  # Note: not needed DEPENDENCIES "fmt 7.1.3"
 )

GNUmakefile

@@ -1,25 +1,24 @@
 #
 # CURDIR=$(/bin/pwd)
-# On UNIX one can use the DESTDIR mechanism in order to relocate the whole installation.
+ROOT?=${CURDIR}/stagedir
-DESTDIR?=${CURDIR}/stagedir
-export DESTDIR
 
-# GENERATOR?="Unix Makefiles"
+#XXX GENERATOR?="Unix Makefiles"
 GENERATOR?=Ninja
 
-export CPM_SOURCE_CACHE=${HOME}/.cache/CPM
+#XXX export CXX=clang++
 export CPM_USE_LOCAL_PACKAGES=1
+export CPM_SOURCE_CACHE=${HOME}/.cache/CPM
 
-.PHONY: update format all test standalone check clean distclean lock
+.PHONY: update format all test standalone doc check clean distclean lock
 
-# the default target does just all
+# the default target does just all, but neither standalone nor doc
 all:
 
 clean:
 	find . -type d -name build | xargs rm -rf
 
 distclean: clean
-	rm -rf build ${DESTDIR}
+	rm -rf build ${ROOT}
 
 # update CPM.cmake
 update:
@@ -31,25 +30,27 @@ lock: standalone all
 	cmake --build build/install --target cpm-update-package-lock
 	cmake --build build/standalone --target cpm-update-package-lock
 
-# install the library
+# install the library to stagedir
 install:
-	cmake -S . -B build/install -G "${GENERATOR}" -DCMAKE_PREFIX_PATH=${DESTDIR} # --trace-expand
+	cmake -S . -B build/install -G "${GENERATOR}" -DCMAKE_PREFIX_PATH=${ROOT} -DCMAKE_INSTALL_PREFIX=${ROOT} # --trace-expand
 	cmake --build build/install --target install
 
 # test the library
 test: install
-	cmake -S test -B build/test -G "${GENERATOR}" -DCMAKE_PREFIX_PATH=${DESTDIR} -DTEST_INSTALLED_VERSION=1
+	cmake -S test -B build/test -G "${GENERATOR}" -DCMAKE_PREFIX_PATH=${ROOT} -DTEST_INSTALLED_VERSION=1
 	cmake --build build/test
 	cmake --build build/test --target test
 
 # all together
 all: test
-	cmake -S all -B build/all -G "${GENERATOR}" -DCMAKE_PREFIX_PATH=${DESTDIR} -DTEST_INSTALLED_VERSION=1 -DENABLE_TEST_COVERAGE=1
+	cmake -S all -B build/all -G "${GENERATOR}" -DCMAKE_PREFIX_PATH=${ROOT} -DTEST_INSTALLED_VERSION=1 -DENABLE_TEST_COVERAGE=1
 	cmake --build build/all
 	cmake --build build/all --target test
-	cmake --build build/all --target GenerateDocs
 	cmake --build build/all --target check-format
 
+doc: all
+	cmake --build build/all --target GenerateDocs
+
 format: distclean
 	find . -name CMakeLists.txt | xargs cmake-format -i
 	find . -name '*.cmake' | xargs cmake-format -i
@@ -57,7 +58,7 @@ format: distclean
 	find . -name '*.h' | xargs clang-format -i
 
 standalone:
-	cmake -S standalone -B build/standalone -G "${GENERATOR}" -DCMAKE_PREFIX_PATH=${DESTDIR} -DCMAKE_EXPORT_COMPILE_COMMANDS=1
+	cmake -S standalone -B build/standalone -G "${GENERATOR}" -DCMAKE_PREFIX_PATH=${ROOT} -DCMAKE_EXPORT_COMPILE_COMMANDS=1
 	cmake --build build/standalone --target all
 
 # check the library

include/greeter/greeter.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <greeter/greeter_export.h>
+
 #include <string>
 
 namespace greeter {
@@ -10,7 +12,7 @@ namespace greeter {
   /**
    * @brief A class for saying hello in multiple languages
    */
-  class Greeter {
+  class GREETER_EXPORT Greeter {
     std::string name;
 
   public:

test/source/greeter.cpp

@@ -16,7 +16,7 @@ TEST_CASE("Greeter") {
 }
 
 TEST_CASE("Greeter version") {
-#if ((__cplusplus >= 201907L) || __cpp_lib_starts_ends_with)
+#if (__APPLE__ || __cpp_lib_starts_ends_with)
   static_assert(std::string_view(GREETER_VERSION).starts_with("1.0"));  // TBD C++20 only
   CHECK(std::string(GREETER_VERSION).starts_with("1.0"));               // SameMajorVersion
 #else