kc3-lang/libbsd

diff --git a/.gitignore b/.gitignore
index 460667b..4018a03 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,5 +20,6 @@ autom4te.cache/
 build-aux/
 configure
 config.*
+format.ld
 libtool
 stamp-h1
diff --git a/configure.ac b/configure.ac
index f40b1af..f0ea291 100644
--- a/configure.ac
+++ b/configure.ac
@@ -101,16 +101,10 @@ AM_CONDITIONAL([HAVE_LIBTESTU01],
                [test "x$ac_cv_lib_testu01_unif01_CreateExternGenBits" = "xyes"])
 
 saved_LIBS="$LIBS"
-AC_SEARCH_LIBS([dlsym], [dl], [
-  AS_IF([test "x$ac_cv_search_dlsym" != "xnone required"], [
-    LIBBSD_LIBS="$LIBBSD_LIBS $ac_cv_search_dlsym"
-  ])
-], [
-  AC_MSG_ERROR([cannot find required dlsym function])
-])
 AC_SEARCH_LIBS([MD5Update], [md], [
   AS_IF([test "x$ac_cv_search_MD5Update" != "xnone required"], [
     MD5_LIBS="$MD5_LIBS $ac_cv_search_MD5Update"
+    need_transparent_libmd=yes
   ])
 ], [
   AC_MSG_ERROR([cannot find required MD5 functions in libc or libmd])
@@ -124,6 +118,9 @@ AC_SEARCH_LIBS([SHA512Update], [md], [
 ])
 LIBS="$saved_LIBS"
 
+AM_CONDITIONAL([NEED_TRANSPARENT_LIBMD],
+               [test "x$need_transparent_libmd" = "xyes"])
+
 is_windows=no
 AS_CASE([$host_os],
   [*-gnu*], [
diff --git a/src/Makefile.am b/src/Makefile.am
index d3f0162..2aa5f5b 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -25,6 +25,7 @@ libbsd_la_included_sources = \
 	getentropy_win.c \
 	$(nil)
 
+CLEANFILES =
 EXTRA_DIST = \
 	libbsd.map \
 	libbsd.pc.in \
@@ -125,22 +126,51 @@ libbsd_la_SOURCES += \
 	$(nil)
 endif
 
+if NEED_TRANSPARENT_LIBMD
+CLEANFILES += \
+	format.ld \
+	# EOL
+endif
+
 libbsd_ctor_a_SOURCES = \
 	setproctitle_ctor.c \
 	$(nil)
 
+if NEED_TRANSPARENT_LIBMD
+TRANSPARENT_LIBMD_DEPENDS = format.ld
+
+format.ld:
+	$(CC) -shared -nostdlib -nostartfiles -x assembler /dev/null -o $@.so
+	objdump -f $@.so | sed -n 's/.*file format \(.*\)/OUTPUT_FORMAT(\1)/;T;p' > $@
+	rm -f $@.so
+endif
+
 runtimelibdir = $(libdir)
 
-install-exec-hook:
+install-exec-hook: $(TRANSPARENT_LIBMD_DEPENDS)
 	if [ "$(libdir)" != "$(runtimelibdir)" ]; then \
 		$(MKDIR_P) $(DESTDIR)$(runtimelibdir); \
 		mv $(DESTDIR)$(libdir)/libbsd*.so.* \
 		   $(DESTDIR)$(runtimelibdir)/; \
+	fi
+if NEED_TRANSPARENT_LIBMD
+# The "GNU ld script" magic is required so that GNU ldconfig does not complain
+# about an unknown format file.
+	soname=`readlink $(DESTDIR)$(libdir)/libbsd.so`; \
+	$(RM) $(DESTDIR)$(libdir)/libbsd.so; \
+	(echo '/* GNU ld script'; \
+	 echo ' * The MD5 functions are provided by the libmd library. */'; \
+	 cat format.ld; \
+	 echo "GROUP($(runtimelibdir)/$$soname AS_NEEDED($(MD5_LIBS)))"; \
+	)>$(DESTDIR)$(libdir)/libbsd.so
+else
+	if [ "$(libdir)" != "$(runtimelibdir)" ]; then \
 		soname=`readlink $(DESTDIR)$(libdir)/libbsd.so`; \
 		sorelprefix=`echo $(libdir) | $(SED) -r -e 's:(^/)?[^/]+:..:g'`; \
 		ln -sf $$sorelprefix$(runtimelibdir)/$$soname \
 		       $(DESTDIR)$(libdir)/libbsd.so; \
 	fi
+endif
 
 uninstall-hook:
 	rm -f $(DESTDIR)$(runtimelibdir)/libbsd*.so*
diff --git a/src/md5.c b/src/md5.c
index 00769aa..1053fcd 100644
--- a/src/md5.c
+++ b/src/md5.c
@@ -24,119 +24,88 @@
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <stddef.h>
-#include <stdlib.h>
-#include <dlfcn.h>
 #include <md5.h>
 #include "local-link.h"
 
-static void (*libmd_MD5Init)(MD5_CTX *);
-static void (*libmd_MD5Update)(MD5_CTX *, const uint8_t *, size_t);
-static void (*libmd_MD5Pad)(MD5_CTX *);
-static void (*libmd_MD5Final)(uint8_t [MD5_DIGEST_LENGTH], MD5_CTX *);
-static void (*libmd_MD5Transform)(uint32_t [4], const uint8_t [MD5_BLOCK_LENGTH]);
-static char *(*libmd_MD5End)(MD5_CTX *, char *);
-static char *(*libmd_MD5File)(const char *, char *);
-static char *(*libmd_MD5FileChunk)(const char *, char *, off_t, off_t);
-static char *(*libmd_MD5Data)(const uint8_t *, size_t, char *);
-
-static void *
-libmd_loader(const char *symbol)
-{
-	void *func;
-
-	func = dlsym(RTLD_NEXT, symbol);
-	if (func == NULL) {
-		fprintf(stderr,
-		        "libbsd: cannot find wrapped symbol %s in libc or libmd\n",
-		        symbol);
-		abort();
-	}
-
-	return func;
-}
-
-#define libmd_wrapper(symbol) \
-	if (libmd_ ## symbol == NULL) \
-		libmd_ ## symbol = libmd_loader(#symbol)
+#pragma GCC diagnostic ignored "-Wmissing-prototypes"
 
 void
-MD5Init(MD5_CTX *context)
+libbsd_MD5Init(MD5_CTX *context)
 {
-	libmd_wrapper(MD5Init);
-	libmd_MD5Init(context);
+	MD5Init(context);
 }
 libbsd_link_warning(MD5Init,
                     "This function is a deprecated wrapper, use libmd instead.");
+libbsd_symver_weak(MD5Init, libbsd_MD5Init, LIBBSD_0.0);
 
 void
-MD5Update(MD5_CTX *context, const uint8_t *data, size_t len)
+libbsd_MD5Update(MD5_CTX *context, const uint8_t *data, size_t len)
 {
-	libmd_wrapper(MD5Update);
-	libmd_MD5Update(context, data, len);
+	MD5Update(context, data, len);
 }
 libbsd_link_warning(MD5Update,
                     "This function is a deprecated wrapper, use libmd instead.");
+libbsd_symver_weak(MD5Update, libbsd_MD5Update, LIBBSD_0.0);
 
 void
-MD5Pad(MD5_CTX *context)
+libbsd_MD5Pad(MD5_CTX *context)
 {
-	libmd_wrapper(MD5Pad);
-	libmd_MD5Pad(context);
+	MD5Pad(context);
 }
 libbsd_link_warning(MD5Pad,
                     "This function is a deprecated wrapper, use libmd instead.");
+libbsd_symver_weak(MD5Pad, libbsd_MD5Pad, LIBBSD_0.0);
 
 void
-MD5Final(uint8_t digest[MD5_DIGEST_LENGTH], MD5_CTX *context)
+libbsd_MD5Final(uint8_t digest[MD5_DIGEST_LENGTH], MD5_CTX *context)
 {
-	libmd_wrapper(MD5Final);
-	libmd_MD5Final(digest, context);
+	MD5Final(digest, context);
 }
 libbsd_link_warning(MD5Final,
                     "This function is a deprecated wrapper, use libmd instead.");
+libbsd_symver_weak(MD5Final, libbsd_MD5Final, LIBBSD_0.0);
 
 void
-MD5Transform(uint32_t state[4], const uint8_t block[MD5_BLOCK_LENGTH])
+libbsd_MD5Transform(uint32_t state[4], const uint8_t block[MD5_BLOCK_LENGTH])
 {
-	libmd_wrapper(MD5Transform);
-	libmd_MD5Transform(state, block);
+	MD5Transform(state, block);
 }
 libbsd_link_warning(MD5Transform,
                     "This function is a deprecated wrapper, use libmd instead.");
+libbsd_symver_weak(MD5Transform, libbsd_MD5Transform, LIBBSD_0.0);
 
 char *
-MD5End(MD5_CTX *context, char *buf)
+libbsd_MD5End(MD5_CTX *context, char *buf)
 {
-	libmd_wrapper(MD5End);
-	return libmd_MD5End(context, buf);
+	return MD5End(context, buf);
 }
 libbsd_link_warning(MD5End,
                     "This function is a deprecated wrapper, use libmd instead.");
+libbsd_symver_weak(MD5End, libbsd_MD5End, LIBBSD_0.0);
 
 char *
-MD5File(const char *filename, char *buf)
+libbsd_MD5File(const char *filename, char *buf)
 {
-	libmd_wrapper(MD5File);
 	return MD5File(filename, buf);
 }
 libbsd_link_warning(MD5File,
                     "This function is a deprecated wrapper, use libmd instead.");
+libbsd_symver_weak(MD5File, libbsd_MD5File, LIBBSD_0.0);
 
 char *
-MD5FileChunk(const char *filename, char *buf, off_t offset, off_t length)
+libbsd_MD5FileChunk(const char *filename, char *buf, off_t offset, off_t length)
 {
-	libmd_wrapper(MD5FileChunk);
-	return libmd_MD5FileChunk(filename, buf, offset, length);
+	return MD5FileChunk(filename, buf, offset, length);
 }
 libbsd_link_warning(MD5FileChunk,
                     "This function is a deprecated wrapper, use libmd instead.");
+libbsd_symver_weak(MD5FileChunk, libbsd_MD5FileChunk, LIBBSD_0.0);
 
 char *
-MD5Data(const uint8_t *data, size_t len, char *buf)
+libbsd_MD5Data(const uint8_t *data, size_t len, char *buf)
 {
-	libmd_wrapper(MD5Data);
-	return libmd_MD5Data(data, len, buf);
+	return MD5Data(data, len, buf);
 }
 libbsd_link_warning(MD5Data,
                     "This function is a deprecated wrapper, use libmd instead.");
+libbsd_symver_weak(MD5Data, libbsd_MD5Data, LIBBSD_0.0);
diff --git a/test/Makefile.am b/test/Makefile.am
index de80b12..33d8aea 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -69,6 +69,11 @@ proctitle_LDFLAGS = \
 check_PROGRAMS += proctitle
 endif
 
+if NEED_TRANSPARENT_LIBMD
+# On the installed system this is handled via the ld script.
+md5_LDADD = $(LDADD) $(MD5_LIBS)
+endif
+
 fgetln_SOURCES = test-stream.c test-stream.h fgetln.c
 fgetln_CFLAGS = -Wno-deprecated-declarations
 fparseln_SOURCES = test-stream.c test-stream.h fparseln.c