Make the libsystemd stuff optional

Makefile.am

 ACLOCAL_AMFLAGS = -I m4
-sbin_PROGRAMS = mboxd mboxctl
+sbin_PROGRAMS = mboxd
+
+# ATM mboxctl depends on the systemd interface
+if HAVE_LIBSYSTEMD
+sbin_PROGRAMS += mboxctl
+endif
 
 mboxd_SOURCES = \
 	mboxd.c \
 	common.c \
 	control.c \
-	control_legacy.c \
-	control_dbus.c \
 	lpc.c \
 	protocol.c \
-	transport_dbus.c \
-	transport_mbox.c \
 	windows.c \
 	mtd.c
 
 mboxd_LINK = $(LINK)
 
+if HAVE_MBOX_TRANSPORT
+mboxd_SOURCES += \
+	transport_mbox.c
+endif
+
+if HAVE_LIBSYSTEMD
+mboxd_SOURCES += \
+	control_legacy.c \
+	control_dbus.c \
+	transport_dbus.c
+endif
+
 mboxd_LDFLAGS = $(LIBSYSTEMD_LIBS)
 mboxd_CFLAGS = $(LIBSYSTEMD_CFLAGS)
 

configure.ac

@@ -21,7 +21,6 @@ AS_IF([test "$HAVE_UAPI_LINUX_LPC_CTRL_H" != ""],
 )
 
 # Checks for typedefs, structures, and compiler characteristics.
-AX_CXX_COMPILE_STDCXX(17, [noext], [mandatory])
 AX_APPEND_COMPILE_FLAGS([-fpic -Wall], [CFLAGS])
 AX_APPEND_COMPILE_FLAGS([-fpic -Wall], [CXXFLAGS])
 
@@ -48,9 +47,16 @@ AS_IF([test "x$enable_oe_sdk" == "xyes"],
 
 AC_ARG_ENABLE([virtual-pnor],
     AS_HELP_STRING([--enable-virtual-pnor], [Turn on virtual pnor])
+    [
+        AS_IF([test "x$CXX" == "x" ],
+              AC_MSG_ERROR([Error virtual-pnor requires c++]))
+    ]
 )
+
 AS_IF([test "x$enable_virtual_pnor" == "xyes"],
     [
+        AX_CXX_COMPILE_STDCXX(17, [noext], [mandatory])
+
         PKG_CHECK_MODULES([SDBUSPLUS], [sdbusplus])
         PKG_CHECK_MODULES([PHOSPHOR_LOGGING], [phosphor-logging])
         PKG_CHECK_MODULES([PHOSPHOR_DBUS_INTERFACES], [phosphor-dbus-interfaces])
@@ -70,7 +76,18 @@ m4_ifdef([_AX_CODE_COVERAGE_RULES],
     [AM_CONDITIONAL(AUTOCONF_CODE_COVERAGE_2019_01_06, [false])])
 AX_ADD_AM_MACRO_STATIC([])
 
-PKG_CHECK_MODULES(LIBSYSTEMD, libsystemd, , AC_MSG_ERROR([libsytemd not found]))
+# ATM unconditionally add mbox transport support
+AM_CONDITIONAL(HAVE_MBOX_TRANSPORT, true)
+
+PKG_CHECK_MODULES(LIBSYSTEMD,
+                  libsystemd,
+                  [
+                   AM_CONDITIONAL(HAVE_LIBSYSTEMD, true)
+                  ],
+                  [
+                   AM_CONDITIONAL(HAVE_LIBSYSTEMD, false)
+                   AC_MSG_WARN([libsytemd not found, building without support.])
+                  ])
 AC_SUBST([LIBSYSTEMD_CFLAGS])
 AC_SUBST([LIBSYSTEMD_LIBS])
 
@@ -79,6 +96,7 @@ AC_DEFINE(PARTITION_FILES_RO_LOC, "/var/lib/phosphor-software-manager/pnor/ro",
 AC_DEFINE(PARTITION_FILES_RW_LOC, "/var/lib/phosphor-software-manager/pnor/rw", [The path to the directory containing PNOR read write partition files.])
 AC_DEFINE(PARTITION_FILES_PRSV_LOC, "/var/lib/phosphor-software-manager/pnor/prsv", [The path to the directory containing PNOR preserve partition files.])
 AC_DEFINE(PARTITION_FILES_PATCH_LOC, "/usr/local/share/pnor", [The path to the directory containing PNOR patch partition files.])
+
 # Create configured output
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT