serial: introduce more general "have serial comm" feature flag

Introduce the HAVE_SERIAL_COMM identifier, which gets derived from, but
need not be identical to the HAVE_LIBSERIALPORT condition.

Derive the NEED_SERIAL automake condition from the general availability
of serial communication not the specific libserialport library.

Adjust source code references. Stick with HAVE_LIBSERIALPORT where the
specific library is meant, but switch to HAVE_SERIAL_COMM where the
availability of serial communication in general is meant.

configure.ac

@@ -96,7 +96,7 @@ SR_PKGLIBS_RUBY=
 SR_EXTRA_LIBS=
 SR_EXTRA_CXX_LIBS=
 
-SR_ARG_OPT_PKG([libserialport], [LIBSERIALPORT], [NEED_SERIAL],
+SR_ARG_OPT_PKG([libserialport], [LIBSERIALPORT], ,
 	[libserialport >= 0.1.1])
 
 SR_ARG_OPT_PKG([libftdi], [LIBFTDI], , [libftdi1 >= 1.0])
@@ -130,6 +130,14 @@ SR_ARG_OPT_CHECK([libieee1284], [LIBIEEE1284],, [
 AS_IF([test "x$sr_have_libieee1284" = xyes],
 	[SR_PREPEND([SR_EXTRA_LIBS], [-lieee1284])])
 
+AS_IF([test "x$sr_have_libserialport" = xyes],
+	sr_have_serial_comm=yes, sr_have_serial_comm=no)
+AS_IF([test "x$sr_have_serial_comm" = xyes],
+	[AC_DEFINE([HAVE_SERIAL_COMM], [1], [Specifies whether serial communication is supported.])])
+AS_IF([test "x$sr_have_serial_comm" = xyes],
+	[SR_APPEND([sr_deps_avail], [serial_comm])])
+AM_CONDITIONAL([NEED_SERIAL], [test "x$sr_have_serial_comm" = xyes])
+
 ######################
 ##  Feature checks  ##
 ######################
@@ -218,6 +226,11 @@ m4_define([_SR_DRIVER], [
 m4_define([SR_DRIVER],
 	[_SR_DRIVER([$1], [$2], m4_expand([AS_TR_CPP([HW_$2])]), [$3])])
 
+# TODO
+# Make device drivers depend on the more generic HAVE_SERIAL_COMM
+# feature flag instead of the specific libserialport, which no longer
+# is the exclusive provider of serial communication support.
+
 SR_DRIVER([Agilent DMM], [agilent-dmm], [libserialport])
 SR_DRIVER([Appa 55II], [appa-55ii], [libserialport])
 SR_DRIVER([Arachnid Labs Re:load Pro], [arachnid-labs-re-load-pro], [libserialport])
@@ -601,10 +614,14 @@ Detected libraries (optional):
 $sr_pkglibs_summary
 Enabled hardware drivers:
 $sr_driver_summary
+Enabled serial communication transports:
+  - serial comm ................... $sr_have_serial_comm
+  - libserialport ................. $sr_have_libserialport
+
 Enabled SCPI backends:
  - TCP............................. yes
  - RPC............................. $sr_cv_have_rpc
- - serial.......................... $sr_have_libserialport
+ - serial.......................... $sr_have_serial_comm
  - VISA............................ $sr_have_librevisa
  - GPIB............................ $sr_have_libgpib
  - USBTMC.......................... $sr_have_libusb

src/backend.c

@@ -205,7 +205,7 @@ SR_API char *sr_buildinfo_scpi_backends_get(void)
 #if HAVE_RPC
 	g_string_append_printf(s, "RPC, ");
 #endif
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 	g_string_append_printf(s, "serial, ");
 #endif
 #ifdef HAVE_LIBREVISA

src/device.c

@@ -518,7 +518,7 @@ SR_PRIV void sr_usb_dev_inst_free(struct sr_usb_dev_inst *usb)
 
 #endif
 
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 
 /**
  * Allocate and init a struct for a serial device instance.
@@ -814,7 +814,7 @@ SR_API const char *sr_dev_inst_connid_get(const struct sr_dev_inst *sdi)
 	struct libusb_device **devlist;
 #endif
 
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 	struct sr_serial_dev_inst *serial;
 #endif
 
@@ -824,7 +824,7 @@ SR_API const char *sr_dev_inst_connid_get(const struct sr_dev_inst *sdi)
 	if (!sdi)
 		return NULL;
 
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 	if ((!sdi->connection_id) && (sdi->inst_type == SR_INST_SERIAL)) {
 		/* connection_id isn't populated, let's do that for serial devices. */
 

src/dmm/asycii.c

@@ -446,7 +446,7 @@ static gboolean flags_valid(const struct asycii_info *info)
 	return TRUE;
 }
 
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 /**
  * Arrange for the reception of another measurement from the DMM.
  *

src/dmm/metex14.c

@@ -329,7 +329,7 @@ static gboolean flags_valid(const struct metex14_info *info)
 	return TRUE;
 }
 
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 SR_PRIV int sr_metex14_packet_request(struct sr_serial_dev_inst *serial)
 {
 	const uint8_t wbuf = 'D';

src/fallback.c

@@ -20,8 +20,9 @@
 #include <config.h>
 #include <glib.h>
 #include <libsigrok/libsigrok.h>
+#include "libsigrok-internal.h"
 
-#ifndef HAVE_LIBSERIALPORT
+#ifndef HAVE_SERIAL_COMM
 
 SR_API GSList *sr_serial_list(const struct sr_dev_driver *driver)
 {

src/libsigrok-internal.h

@@ -26,6 +26,8 @@
 #ifndef LIBSIGROK_LIBSIGROK_INTERNAL_H
 #define LIBSIGROK_LIBSIGROK_INTERNAL_H
 
+#include "config.h"
+
 #include <glib.h>
 #ifdef HAVE_LIBSERIALPORT
 #include <libserialport.h>
@@ -721,7 +723,7 @@ struct sr_usb_dev_inst {
 };
 #endif
 
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 struct ser_lib_functions;
 struct sr_serial_dev_inst {
 	/** Port name, e.g. '/dev/tty42'. */
@@ -840,7 +842,7 @@ SR_PRIV struct sr_usb_dev_inst *sr_usb_dev_inst_new(uint8_t bus,
 SR_PRIV void sr_usb_dev_inst_free(struct sr_usb_dev_inst *usb);
 #endif
 
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 /* Serial-specific instances */
 SR_PRIV struct sr_serial_dev_inst *sr_serial_dev_inst_new(const char *port,
 		const char *serialcomm);
@@ -957,7 +959,7 @@ SR_PRIV int std_dummy_dev_open(struct sr_dev_inst *sdi);
 SR_PRIV int std_dummy_dev_close(struct sr_dev_inst *sdi);
 SR_PRIV int std_dummy_dev_acquisition_start(const struct sr_dev_inst *sdi);
 SR_PRIV int std_dummy_dev_acquisition_stop(struct sr_dev_inst *sdi);
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 SR_PRIV int std_serial_dev_open(struct sr_dev_inst *sdi);
 SR_PRIV int std_serial_dev_acquisition_stop(struct sr_dev_inst *sdi);
 #endif
@@ -1067,7 +1069,7 @@ SR_PRIV int soft_trigger_logic_check(struct soft_trigger_logic *st, uint8_t *buf
 
 /*--- serial.c --------------------------------------------------------------*/
 
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 enum {
 	SERIAL_RDWR = 1,
 	SERIAL_RDONLY = 2,
@@ -1385,7 +1387,7 @@ struct metex14_info {
 	gboolean is_hfe, is_unitless, is_logic, is_min, is_max, is_avg;
 };
 
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 SR_PRIV int sr_metex14_packet_request(struct sr_serial_dev_inst *serial);
 #endif
 SR_PRIV gboolean sr_metex14_packet_valid(const uint8_t *buf);
@@ -1516,7 +1518,7 @@ struct asycii_info {
 	gboolean is_invalid;
 };
 
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 SR_PRIV int sr_asycii_packet_request(struct sr_serial_dev_inst *serial);
 #endif
 SR_PRIV gboolean sr_asycii_packet_valid(const uint8_t *buf);

src/modbus/modbus.c

@@ -28,7 +28,7 @@
 SR_PRIV extern const struct sr_modbus_dev_inst modbus_serial_rtu_dev;
 
 static const struct sr_modbus_dev_inst *modbus_devs[] = {
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 	&modbus_serial_rtu_dev, /* Must be last as it matches any resource. */
 #endif
 };

src/scpi/scpi.c

@@ -100,7 +100,7 @@ static const struct sr_scpi_dev_inst *scpi_devs[] = {
 #ifdef HAVE_LIBGPIB
 	&scpi_libgpib_dev,
 #endif
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 	&scpi_serial_dev, /* Must be last as it matches any resource. */
 #endif
 };

src/std.c

@@ -305,7 +305,7 @@ SR_PRIV int std_session_send_frame_end(const struct sr_dev_inst *sdi)
 	return SR_OK;
 }
 
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 
 /**
  * Standard serial driver dev_open() callback API helper.
@@ -454,7 +454,7 @@ SR_PRIV int std_dev_clear_with_callback(const struct sr_dev_driver *driver,
 			driver->dev_close(sdi);
 
 		if (sdi->conn) {
-#ifdef HAVE_LIBSERIALPORT
+#ifdef HAVE_SERIAL_COMM
 			if (sdi->inst_type == SR_INST_SERIAL)
 				sr_serial_dev_inst_free(sdi->conn);
 #endif