build-sys: create "compatibility libraries" section

Compat stuff is moved to src/compat-libs/.
Warnings are issued when programs are linked with the deprecated library.

1 files changed, 34 insertions, 0 deletions

diff --git a/src/compat-libs/linkwarning.h b/src/compat-libs/linkwarning.h
new file mode 100644
index 0000000000..b6a6ac2940
--- /dev/null
+++ b/src/compat-libs/linkwarning.h
@@ -0,0 +1,34 @@
+/***
+  This file is part of systemd, but is heavily based on
+  glibc's libc-symbols.h.
+
+  Copyright (C) 1995-1998,2000-2006,2008,2009 Free Software Foundation, Inc
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+
+#define __make_section_unallocated(section_string)      \
+  asm (".section " section_string "\n\t.previous");
+
+#define __sec_comment "\n#APP\n\t#"
+
+#define link_warning(symbol, msg) \
+  __make_section_unallocated (".gnu.warning." #symbol)  \
+  static const char __evoke_link_warning_##symbol[]     \
+    __attribute__ ((used, section (".gnu.warning." #symbol __sec_comment))) \
+    = msg
+
+#define obsolete_lib(name, lib)                         \
+  link_warning(name, #name " was moved to libsystemd. Do not use " #lib ".")