Commit 9cc938450392d64440de5c7db27903dff9922728

Guillem Jover 2019-08-28T11:19:37

Import local-link header from libbsd This provides several macros for versioned symbols and linking magic.

diff --git a/src/Makefile.am b/src/Makefile.am
index 77f07b1..e17a7ab 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -13,6 +13,7 @@ pkgconfig_DATA = \
 lib_LTLIBRARIES = libmd.la
 
 libmd_la_helper_sources = \
+	local-link.h \
 	md2hl.c \
 	md4hl.c \
 	md5hl.c \
diff --git a/src/local-link.h b/src/local-link.h
new file mode 100644
index 0000000..7f84f9e
--- /dev/null
+++ b/src/local-link.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright © 2015, 2019 Guillem Jover <guillem@hadrons.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef LIBMD_LOCAL_LINK_H
+#define LIBMD_LOCAL_LINK_H
+
+#define libmd_link_warning(symbol, msg) \
+	static const char libmd_emit_link_warning_##symbol[] \
+		__attribute__((__used__,__section__(".gnu.warning." #symbol))) = msg;
+
+#ifdef __ELF__
+#define libmd_symver_default(alias, symbol, version) \
+	__asm__(".symver " #symbol "," #alias "@@" #version)
+
+#define libmd_symver_variant(alias, symbol, version) \
+	__asm__(".symver " #symbol "," #alias "@" #version)
+#else
+#define libmd_symver_default(alias, symbol, version) \
+	extern __typeof(symbol) alias __attribute__((__alias__(#symbol)))
+
+#define libmd_symver_variant(alias, symbol, version)
+#endif
+
+#endif