build: Don't check for dlfcn.h and dl.h

It's enough to check for symbols.

CMakeLists.txt

@@ -313,19 +313,16 @@ target_include_directories(
 )
 
 if(LIBXML2_WITH_MODULES)
-    check_include_files(dlfcn.h HAVE_DLFCN_H)
     check_library_exists(dl dlopen "" HAVE_DLOPEN)
-    check_include_files(dl.h HAVE_DL_H)
-    check_library_exists(dld shl_load "" HAVE_SHLLOAD)
-
     if(HAVE_DLOPEN)
         target_link_libraries(LibXml2 PRIVATE dl)
         set(MODULE_LIBS "-ldl")
-    endif()
-
-    if(HAVE_SHLLOAD)
-        target_link_libraries(LibXml2 PRIVATE dld)
-        set(MODULE_LIBS "-ldld")
+    else()
+        check_library_exists(dld shl_load "" HAVE_SHLLOAD)
+        if(HAVE_SHLLOAD)
+            target_link_libraries(LibXml2 PRIVATE dld)
+            set(MODULE_LIBS "-ldld")
+        endif()
     endif()
 endif()
 

config.h.cmake.in

@@ -12,15 +12,9 @@
 /* Define if __attribute__((destructor)) is accepted */
 #cmakedefine HAVE_FUNC_ATTRIBUTE_DESTRUCTOR 1
 
-/* Define to 1 if you have the <dlfcn.h> header file. */
-#cmakedefine HAVE_DLFCN_H 1
-
 /* Have dlopen based dso */
 #cmakedefine HAVE_DLOPEN 1
 
-/* Define to 1 if you have the <dl.h> header file. */
-#cmakedefine HAVE_DL_H 1
-
 /* Define if history library is there (-lhistory) */
 #cmakedefine HAVE_LIBHISTORY 1
 

configure.ac

@@ -661,8 +661,6 @@ if test "$with_modules" != "no" ; then
     esac
 
     if test "$WITH_MODULES" = "0"; then
-        AC_CHECK_HEADERS([dl.h dlfcn.h])
-
         _libs=$LIBS
         AC_SEARCH_LIBS([dlopen], [dl], [
             WITH_MODULES=1

meson.build

@@ -236,9 +236,6 @@ xml_check_headers = [
     [ 'stdint.h', true ],
     [ 'glob.h', true ],
 
-    [ 'dl.h', want_modules ],
-    [ 'dlfcn.h', want_modules ],
-
     [ 'sys/socket.h', want_http ],
     [ 'netinet/in.h', want_http ],
     [ 'arpa/inet.h', want_http ],

xmlmodule.c

@@ -157,9 +157,7 @@ xmlModuleFree(xmlModulePtr module)
 }
 
 #if defined(HAVE_DLOPEN) && !defined(_WIN32)
-#ifdef HAVE_DLFCN_H
 #include <dlfcn.h>
-#endif
 
 #ifndef RTLD_GLOBAL            /* For Tru64 UNIX 4.0 */
 #define RTLD_GLOBAL 0
@@ -210,9 +208,7 @@ xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
 #else /* ! HAVE_DLOPEN */
 
 #ifdef HAVE_SHLLOAD             /* HAVE_SHLLOAD */
-#ifdef HAVE_DL_H
 #include <dl.h>
-#endif
 /*
  * xmlModulePlatformOpen:
  * returns a handle on success, and zero on error.