Fix 'unknown option --no-undefined' linker error in cmake script (OS X)

Use check_linker_flag() and LINKER prefix in CMakeLists.txt.
This fixes the linker error that "--no-undefined" option is unknown,
at least with apple-clang 13.0.

* CMakeLists.txt [CMP0057] (CMP0057): Set to NEW.
* CMakeLists.txt [$CMAKE_VERSION<3.18.0]: Include CheckLinkerFlag.
* CMakeLists.txt [BUILD_SHARED_LIBS] (WL_NO_UNDEFINED_OPT): New
variable.
* CMakeLists.txt [BUILD_SHARED_LIBS && $CMAKE_VERSION>=3.18.0]
(WL_NO_UNDEFINED_OPT): Use "LINKER:" prefix.
* CMakeLists.txt [BUILD_SHARED_LIBS && $CMAKE_VERSION>=3.18.0]
(HAVE_FLAG_WL_NO_UNDEFINED): Use check_linker_flag(C) instead of
check_c_compiler_flag.
* CMakeLists.txt [BUILD_SHARED_LIBS && $CMAKE_VERSION<3.13.0] (gc,
gccpp, gctba, cord): Use $WL_NO_UNDEFINED_OPT.
* CMakeLists.txt [BUILD_SHARED_LIBS && $CMAKE_VERSION>=3.13.0] (gc,
gccpp, gctba, cord): Use target_link_options instead of
target_link_libraries; remove TODO item.

1 files changed, 39 insertions, 12 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a670acc3..79babc17 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -41,6 +41,11 @@ else()
   project(gc C)
 endif()
 
+if (POLICY CMP0057)
+  # Required for CheckLinkerFlag, at least.
+  cmake_policy(SET CMP0057 NEW)
+endif()
+
 include(CheckCCompilerFlag)
 include(CheckCSourceCompiles)
 include(CheckFunctionExists)
@@ -50,6 +55,10 @@ include(CMakePackageConfigHelpers)
 include(CTest)
 include(GNUInstallDirs)
 
+if (NOT (${CMAKE_VERSION} VERSION_LESS "3.18.0"))
+  include(CheckLinkerFlag)
+endif()
+
 # Customize the build by passing "-D<option_name>=ON|OFF" in the command line.
 option(BUILD_SHARED_LIBS "Build shared libraries" ON)
 option(build_cord "Build cord library" ON)
@@ -434,7 +443,13 @@ if (BUILD_SHARED_LIBS)
   else()
     add_definitions("-DGC_NO_VISIBILITY")
   endif()
-  check_c_compiler_flag(-Wl,--no-undefined HAVE_FLAG_WL_NO_UNDEFINED)
+  if (${CMAKE_VERSION} VERSION_LESS "3.18.0")
+    set(WL_NO_UNDEFINED_OPT "-Wl,--no-undefined")
+    check_c_compiler_flag(${WL_NO_UNDEFINED_OPT} HAVE_FLAG_WL_NO_UNDEFINED)
+  else()
+    set(WL_NO_UNDEFINED_OPT "LINKER:--no-undefined")
+    check_linker_flag(C "${WL_NO_UNDEFINED_OPT}" HAVE_FLAG_WL_NO_UNDEFINED)
+  endif()
 else()
   add_definitions("-DGC_NOT_DLL")
   if (WIN32)
@@ -576,17 +591,29 @@ endif(build_cord)
 
 if (BUILD_SHARED_LIBS AND HAVE_FLAG_WL_NO_UNDEFINED)
   # Declare that the libraries do not refer to external symbols.
-  # TODO: use add_link_options() when cmake_minimum_required > 3.13
-  target_link_libraries(gc PRIVATE -Wl,--no-undefined)
-  if (enable_cplusplus)
-    target_link_libraries(gccpp PRIVATE -Wl,--no-undefined)
-    if (enable_throw_bad_alloc_library)
-      target_link_libraries(gctba PRIVATE -Wl,--no-undefined)
-    endif(enable_throw_bad_alloc_library)
-  endif(enable_cplusplus)
-  if (build_cord)
-    target_link_libraries(cord PRIVATE -Wl,--no-undefined)
-  endif(build_cord)
+  if (${CMAKE_VERSION} VERSION_LESS "3.13.0")
+    target_link_libraries(gc PRIVATE ${WL_NO_UNDEFINED_OPT})
+    if (enable_cplusplus)
+      target_link_libraries(gccpp PRIVATE ${WL_NO_UNDEFINED_OPT})
+      if (enable_throw_bad_alloc_library)
+        target_link_libraries(gctba PRIVATE ${WL_NO_UNDEFINED_OPT})
+      endif(enable_throw_bad_alloc_library)
+    endif(enable_cplusplus)
+    if (build_cord)
+      target_link_libraries(cord PRIVATE ${WL_NO_UNDEFINED_OPT})
+    endif(build_cord)
+  else()
+    target_link_options(gc PRIVATE ${WL_NO_UNDEFINED_OPT})
+    if (enable_cplusplus)
+      target_link_options(gccpp PRIVATE ${WL_NO_UNDEFINED_OPT})
+      if (enable_throw_bad_alloc_library)
+        target_link_options(gctba PRIVATE ${WL_NO_UNDEFINED_OPT})
+      endif(enable_throw_bad_alloc_library)
+    endif(enable_cplusplus)
+    if (build_cord)
+      target_link_options(cord PRIVATE ${WL_NO_UNDEFINED_OPT})
+    endif(build_cord)
+  endif()
 endif()
 
 if (BUILD_SHARED_LIBS)