From 84d70e63fc105e3713943ed8c0bdd4e31a698226 Mon Sep 17 00:00:00 2001
From: Joachim Nilsson <troglobit@gmail.com>
Date: Thu, 16 Jan 2020 22:16:51 +0100
Subject: [PATCH] Drop libcompat to simplify build deps and really fix #11

The original idea with libcompat was to keep as few objects as
possible for linking with libsyslog.  That in turn to prevent
a user of libsyslog from suddenly also getting strong binding
to symbols like strlcpy() from libsyslog, rather than their C
library of choice.

However, this caused strlcpy.c to be built as both .o and .lo
files, which in turn caused really bizarre build problems due
to bad DAG dependency.

This patch drops libcompat and instead marks all replacement APIs
as weak symbols, which a C library can override.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
---
 Makefile.am     |  4 ----
 lib/pidfile.c   |  8 +++++++-
 lib/utimensat.c | 10 ++++++++--
 src/Makefile.am |  7 +------
 4 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 846738b..b7cafda 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -51,7 +51,3 @@ release: distcheck
 
 # Workaround for systemd unit file duing distcheck
 DISTCHECK_CONFIGURE_FLAGS = --with-systemd=$$dc_install_base/$(systemd)
-
-# Disable parallel build in top Makefile, we might otherwise get a very
-# bizarre build problem with strlcpy.o in libcompat and for syslogd.
-.NOTPARALLEL:
diff --git a/lib/pidfile.c b/lib/pidfile.c
index 81f2315..8b5f517 100644
--- a/lib/pidfile.c
+++ b/lib/pidfile.c
@@ -31,6 +31,9 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <config.h>
+#ifndef HAVE_PIDFILE
+
 #define _GNU_SOURCE		/* Needed with GLIBC to get asprintf() */
 #include <sys/stat.h>		/* utimensat() */
 #include <sys/time.h>		/* utimensat() on *BSD */
@@ -54,7 +57,7 @@ const  char *__pidfile_path = RUNSTATEDIR;
 const  char *__pidfile_name = NULL;
 
 int
-pidfile(const char *basename)
+__pidfile(const char *basename)
 {
 	int save_errno;
 	int atexit_already;
@@ -136,3 +139,6 @@ pidfile_cleanup(void)
 		pidfile_path = NULL;
 	}
 }
+
+weak_alias(__pidfile, pidfile);
+#endif /* HAVE_PIDFILE */
diff --git a/lib/utimensat.c b/lib/utimensat.c
index edf7e10..b68ce0e 100644
--- a/lib/utimensat.c
+++ b/lib/utimensat.c
@@ -15,7 +15,8 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-#include "config.h"
+#include <config.h>
+#ifndef HAVE_UTIMENSAT
 
 #include <errno.h>
 #ifdef HAVE_FCNTL_H
@@ -23,7 +24,8 @@
 #endif
 #include <sys/time.h>		/* lutimes(), utimes(), utimensat() */
 
-int utimensat(int dirfd, const char *pathname, const struct timespec ts[2], int flags)
+int
+__utimensat(int dirfd, const char *pathname, const struct timespec ts[2], int flags)
 {
 	int ret = -1;
 	struct timeval tv[2];
@@ -45,3 +47,7 @@ int utimensat(int dirfd, const char *pathname, const struct timespec ts[2], int
 
 	return ret;
 }
+
+weak_alias(__utimensat, utimensat);
+
+#endif /* HAVE_UTIMENSAT */
diff --git a/src/Makefile.am b/src/Makefile.am
index 57fe786..207a137 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -28,7 +28,6 @@
 bin_PROGRAMS          =
 sbin_PROGRAMS         = syslogd
 lib_LTLIBRARIES       = libsyslog.la
-noinst_LTLIBRARIES    = libcompat.la
 
 if ENABLE_LOGGER
 bin_PROGRAMS	     += logger
@@ -48,10 +47,6 @@ logger_CPPFLAGS       = $(AM_CPPFLAGS) -D_XOPEN_SOURCE=600
 logger_LDADD          = $(LIBS) $(LIBOBJS)
 logger_LDADD         += libsyslog.la
 
-# Convenience library for libsyslog instead of linking with $(LTLIBOBJS),
-# which would pull in pidfile() and other (strong) symbols as well.
-libcompat_la_SOURCES  = ../lib/strlcpy.c ../lib/strlcat.c
-
 pkgconfigdir          = $(libdir)/pkgconfig
 pkgincludedir         = $(includedir)/syslog
 pkgconfig_DATA        = libsyslog.pc
@@ -59,4 +54,4 @@ pkginclude_HEADERS    = syslog.h
 libsyslog_la_SOURCES  = syslog.c syslog.h compat.h
 libsyslog_la_CPPFLAGS = $(AM_CPPFLAGS) -D_XOPEN_SOURCE=600
 libsyslog_la_LDFLAGS  = $(AM_LDFLAGS) -version-info 0:0:0
-libsyslog_la_LIBADD   = libcompat.la
+libsyslog_la_LIBADD   = $(LTLIBOJBS)