"transport select" returns Jim value

Make it scriptable, so code can be conditionalized based on
what transport is in use for the session.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

2 files changed, 31 insertions, 42 deletions

diff --git a/doc/openocd.texi b/doc/openocd.texi
index 89c9f668..97d2e816 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -2451,7 +2451,7 @@ version of OpenOCD.
 Select which of the supported transports to use in this OpenOCD session.
 The transport must be supported by the debug adapter hardware  and by the
 version of OPenOCD you are using (including the adapter's driver).
-No arguments: print selected transport..
+No arguments: returns name of session's selected transport.
 @end deffn
 
 @subsection JTAG Transport
diff --git a/src/jtag/transport.c b/src/jtag/transport.c
index d290bd2c..503b57b6 100644
--- a/src/jtag/transport.c
+++ b/src/jtag/transport.c
@@ -46,6 +46,9 @@
 
 #include "transport.h"
 
+extern struct command_context *global_cmd_ctx;
+
+
 /*-----------------------------------------------------------------------*/
 
 /*
@@ -272,39 +275,26 @@ COMMAND_HANDLER(handle_transport_list)
 /**
  * Implements the Tcl "transport select" command, choosing the
  * transport to be used in this debug session from among the
- * set supported by the debug adapter being used.
+ * set supported by the debug adapter being used.  Return value
+ * is scriptable (allowing "if swd then..." etc).
  */
-COMMAND_HANDLER(handle_transport_select)
+static int jim_transport_select(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
-	int retval = ERROR_OK;;
-
-	switch (CMD_ARGC) {
-	case 0:			/* "select" */
-		if (session) {
-			goto show;
-		}
-		LOG_ERROR("session's transport is not selected.");
-		return ERROR_FAIL;
-
-	case 1:			/* "select FOO" */
-		if ((session!= NULL) && strcmp(session->name, CMD_ARGV[0]) == 0) {
-			/* NOP */
-			LOG_DEBUG("transport '%s' is already selected",
-					CMD_ARGV[0]);
-			return ERROR_OK;
+	switch (argc) {
+	case 1:			/* return/display */
+		if (!session) {
+			LOG_ERROR("session's transport is not selected.");
+			return JIM_ERR;
 		} else {
-			/* we can't change this session's transport after-the-fact */
-			if (session) {
-				LOG_ERROR("session's transport is already selected.");
-				return ERROR_FAIL;
-			}
+			Jim_SetResultString(interp, session->name, -1);
+			return JIM_OK;
 		}
 		break;
-
-	default:		/* select FOO BAR */
-		/* we only select *one* transport per session */
-		LOG_ERROR("may only select one transport!");
-		return ERROR_COMMAND_SYNTAX_ERROR;
+	case 2:			/* assign */
+	if (session) {
+		/* can't change session's transport after-the-fact */
+		LOG_ERROR("session's transport is already selected.");
+		return JIM_ERR;
 	}
 
 	/* Is this transport supported by our debug adapter?
@@ -315,24 +305,23 @@ COMMAND_HANDLER(handle_transport_select)
 	 */
 	if (!allowed_transports) {
 		LOG_ERROR("Debug adapter doesn't support any transports?");
-		return ERROR_FAIL;
+		return JIM_ERR;
 	}
 
 	for (unsigned i = 0; allowed_transports[i]; i++) {
 
-		if (strcmp(allowed_transports[i], CMD_ARGV[0]) == 0)
-			return transport_select(CMD_CTX, CMD_ARGV[0]);
+		if (strcmp(allowed_transports[i], argv[0]->bytes) == 0)
+		return transport_select(global_cmd_ctx, argv[0]->bytes);
 	}
 
-	LOG_ERROR("Debug adapter doesn't support '%s' "
-			"transport?", CMD_ARGV[0]);
-	return ERROR_FAIL;
-
-
-show:
-	/* report the current transport selection */
-	command_print(CMD_CTX, "%s", session->name);
-	return retval;
+		LOG_ERROR("Debug adapter doesn't support '%s' "
+			"transport", argv[0]->bytes);
+		return JIM_ERR;
+		break;
+	default:
+		Jim_WrongNumArgs(interp, 1, argv, "[too many parameters]");
+		return JIM_ERR;
+	}
 }
 
 static const struct command_registration transport_commands[] = {
@@ -354,7 +343,7 @@ static const struct command_registration transport_commands[] = {
 	},
 	{
 		.name = "select",
-		.handler = handle_transport_select,
+		.jim_handler = jim_transport_select,
 		.mode = COMMAND_ANY,
 		.help = "Select this session's transport",
 		.usage = "[transport_name]",