feat(Core/Build): add the possibility to link libraries dynamically (#5348)

src/cmake/compiler/clang/settings.cmake

@@ -8,6 +8,14 @@ target_compile_definitions(acore-compile-option-interface
   INTERFACE
     -D_BUILD_DIRECTIVE="${CMAKE_BUILD_TYPE}")
 
+set(CLANG_EXPECTED_VERSION 6.0.0)
+
+if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS CLANG_EXPECTED_VERSION)
+  message(FATAL_ERROR "Clang: AzerothCore requires version ${CLANG_EXPECTED_VERSION} to build but found ${CMAKE_CXX_COMPILER_VERSION}")
+else()
+  message(STATUS "Clang: Minimum version required is ${CLANG_EXPECTED_VERSION}, found ${CMAKE_CXX_COMPILER_VERSION} - ok!")
+endif()
+
 # This tests for a bug in clang-7 that causes linkage to fail for 64-bit from_chars (in some configurations)
 # If the clang requirement is bumped to >= clang-8, you can remove this check, as well as
 # the associated ifdef block in src/common/Utilities/StringConvert.h
@@ -59,6 +67,20 @@ target_compile_options(acore-compile-option-interface
     -Wno-narrowing
     -Wno-deprecated-register)
 
-target_compile_definitions(acore-compile-option-interface
-  INTERFACE
-    -DDEBUG=1)
+if(BUILD_SHARED_LIBS)
+    # -fPIC is needed to allow static linking in shared libs.
+    # -fvisibility=hidden sets the default visibility to hidden to prevent exporting of all symbols.
+    target_compile_options(acore-compile-option-interface
+      INTERFACE
+        -fPIC)
+
+    target_compile_options(acore-hidden-symbols-interface
+      INTERFACE
+        -fvisibility=hidden)
+
+    # --no-undefined to throw errors when there are undefined symbols
+    # (caused through missing WARHEAD_*_API macros).
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --no-undefined")
+
+    message(STATUS "Clang: Disallow undefined symbols")
+endif()

src/cmake/compiler/gcc/settings.cmake

@@ -8,10 +8,12 @@ target_compile_definitions(acore-compile-option-interface
   INTERFACE
     -D_BUILD_DIRECTIVE="${CMAKE_BUILD_TYPE}")
 
-set(GCC_EXPECTED_VERSION 4.8.2)
+set(GCC_EXPECTED_VERSION 7.0.0)
 
 if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS GCC_EXPECTED_VERSION)
   message(FATAL_ERROR "GCC: This project requires version ${GCC_EXPECTED_VERSION} to build but found ${CMAKE_CXX_COMPILER_VERSION}")
+else()
+  message(STATUS "GCC: Minimum version required is ${GCC_EXPECTED_VERSION}, found ${CMAKE_CXX_COMPILER_VERSION} - ok!")
 endif()
 
 if(PLATFORM EQUAL 32)
@@ -47,3 +49,21 @@ if( WITH_COREDEBUG )
     -g3)
   message(STATUS "GCC: Debug-flags set (-g3)")
 endif()
+
+if(BUILD_SHARED_LIBS)
+  target_compile_options(acore-compile-option-interface
+    INTERFACE
+      -fPIC
+      -Wno-attributes)
+
+  target_compile_options(acore-hidden-symbols-interface
+    INTERFACE
+      -fvisibility=hidden)
+
+  # Should break the build when there are WARHEAD_*_API macros missing
+  # but it complains about missing references in precompiled headers.
+  # set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wl,--no-undefined")
+  # set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wl,--no-undefined")
+
+  message(STATUS "GCC: Enabled shared linking")
+endif()

src/cmake/compiler/msvc/settings.cmake

@@ -6,9 +6,14 @@
 # set up output paths for executable binaries (.exe-files, and .dll-files on DLL-capable platforms)
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
 
-# set up output paths ofr static libraries etc (commented out - shown here as an example only)
-#set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
-#set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+set(MSVC_EXPECTED_VERSION 19.24)
+set(MSVC_EXPECTED_VERSION_STRING "Microsoft Visual Studio 2019 16.4")
+
+if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS MSVC_EXPECTED_VERSION)
+  message(FATAL_ERROR "MSVC: AzerothCore requires version ${MSVC_EXPECTED_VERSION} (${MSVC_EXPECTED_VERSION_STRING}) to build but found ${CMAKE_CXX_COMPILER_VERSION}")
+else()
+  message(STATUS "MSVC: Minimum version required is ${MSVC_EXPECTED_VERSION}, found ${CMAKE_CXX_COMPILER_VERSION} - ok!")
+endif()
 
 # CMake sets warning flags by default, however we manage it manually
 # for different core and dependency targets
@@ -106,6 +111,14 @@ if(NOT WITH_WARNINGS)
   endif()
 endif()
 
+# Ignore specific warnings
+# C4351: new behavior: elements of array 'x' will be default initialized
+# C4091: 'typedef ': ignored on left of '' when no variable is declared
+target_compile_options(acore-compile-option-interface
+  INTERFACE
+    /wd4351
+    /wd4091)
+
 # Specify the maximum PreCompiled Header memory allocation limit
 # Fixes a compiler-problem when using PCH - the /Ym flag is adjusted by the compiler in MSVC2012, hence we need to set an upper limit with /Zm to avoid discrepancies)
 # (And yes, this is a verified , unresolved bug with MSVC... *sigh*)
@@ -119,3 +132,26 @@ target_compile_options(acore-warning-interface
   INTERFACE
     /we4263
     /we4264)
+
+if(BUILD_SHARED_LIBS)
+  # C4251: needs to have dll-interface to be used by clients of class '...'
+  # C4275: non dll-interface class ...' used as base for dll-interface class '...'
+  target_compile_options(acore-compile-option-interface
+    INTERFACE
+      /wd4251
+      /wd4275)
+
+  message(STATUS "MSVC: Enabled shared linking")
+endif()
+
+# Disable incremental linking in debug builds.
+# To prevent linking getting stuck (which might be fixed in a later VS version).
+macro(DisableIncrementalLinking variable)
+string(REGEX REPLACE "/INCREMENTAL *" "" ${variable} "${${variable}}")
+set(${variable} "${${variable}} /INCREMENTAL:NO")
+endmacro()
+
+DisableIncrementalLinking(CMAKE_EXE_LINKER_FLAGS_DEBUG)
+DisableIncrementalLinking(CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO)
+DisableIncrementalLinking(CMAKE_SHARED_LINKER_FLAGS_DEBUG)
+DisableIncrementalLinking(CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO)