[glib: 1/2] Check for RTLD_NEXT

[Philip Withnall <pwithnall src gnome org>]

commit a53ff7460ef6f03d8e602186b721baea16bfef9f
Author: Руслан Ижбулатов <lrn1986 gmail com>
Date:   Wed Mar 20 18:52:48 2019 +0000

    Check for RTLD_NEXT
    
    Check for RTLD_NEXT being present, and disable the gsocketclient-slow
    test if it's absent, since the shlib dependency of that test requires
    RTLD_NEXT to function.
    
    This allows the testsuite to be built on Cygwin, which behaves
    exactly like UNIX, but doesn't have RTLD_NEXT.

 gio/tests/meson.build | 39 ++++++++++++++++++++++-----------------
 meson.build           |  6 ++++++
 2 files changed, 28 insertions(+), 17 deletions(-)
---
diff --git a/gio/tests/meson.build b/gio/tests/meson.build
index bdd76f0f8..a3efd33ab 100644
--- a/gio/tests/meson.build
+++ b/gio/tests/meson.build
@@ -136,27 +136,32 @@ if host_machine.system() != 'windows'
     'unix-mounts' : {},
     'unix-streams' : {},
     'g-file-info-filesystem-readonly' : {},
-    'gsocketclient-slow' : {
-      'depends' : [
-        shared_library('slow-connect-preload',
-          'slow-connect-preload.c',
-          name_prefix : '',
-          dependencies: cc.find_library('dl'),
-          install_dir : installed_tests_execdir,
-          install: installed_tests_enabled,
-        )
-      ],
-      'env' : {
-        'LD_PRELOAD': '@0@/slow-connect-preload.so'.format(meson.current_build_dir())
-      },
-      'installed_tests_env' : {
-        'LD_PRELOAD': '@0@/slow-connect-preload.so'.format(installed_tests_execdir),
-      },
-    },
     'gschema-compile' : {'install' : false},
     'trash' : {},
   }
 
+  if have_rtld_next
+    gio_tests += {
+      'gsocketclient-slow' : {
+        'depends' : [
+          shared_library('slow-connect-preload',
+            'slow-connect-preload.c',
+            name_prefix : '',
+            dependencies: cc.find_library('dl'),
+            install_dir : installed_tests_execdir,
+            install: installed_tests_enabled,
+          )
+        ],
+        'env' : {
+          'LD_PRELOAD': '@0@/slow-connect-preload.so'.format(meson.current_build_dir())
+        },
+        'installed_tests_env' : {
+          'LD_PRELOAD': '@0@/slow-connect-preload.so'.format(installed_tests_execdir),
+        },
+      },
+    }
+  endif
+
   # Uninstalled because of the check-for-executable logic in DesktopAppInfo
   # unable to find the installed executable
   if not glib_have_cocoa
diff --git a/meson.build b/meson.build
index d937b5fa3..75659888c 100644
--- a/meson.build
+++ b/meson.build
@@ -584,6 +584,12 @@ if cc.has_header_symbol('dlfcn.h', 'RTLD_GLOBAL')
   glib_conf.set('HAVE_RTLD_GLOBAL', 1)
 endif
 
+have_rtld_next = false
+if cc.has_header_symbol('dlfcn.h', 'RTLD_NEXT')
+  have_rtld_next = true
+  glib_conf.set('HAVE_RTLD_NEXT', 1)
+endif
+
 # Check whether to use statfs or statvfs
 # Some systems have both statfs and statvfs, pick the most "native" for these
 if have_func_statfs and have_func_statvfs