transport: make 'transport select' auto-select the first available transport if not set

[fw/openocd] / src / transport / transport.c

diff --git a/src/transport/transport.c b/src/transport/transport.c
index 06f09c99882137242a4b4c7dfe171b4b7e3410e1..c973e1c3a9ff783f344ee608ef5663ffd5583a4e 100644 (file)
--- a/src/transport/transport.c
+++ b/src/transport/transport.c
@@ -61,7 +61,7 @@ static struct transport *transport_list;
  * currently selected debug adapter supports.  This is declared
  * by the time that adapter is fully set up.
  */
-static const char **allowed_transports;
+static const char * const *allowed_transports;
 
 /** * The transport being used for the current OpenOCD session.  */
 static struct transport *session;
@@ -94,7 +94,7 @@ static int transport_select(struct command_context *ctx, const char *name)
  * to declare the set of transports supported by an adapter.  When
  * there is only one member of that set, it is automatically selected.
  */
-int allow_transports(struct command_context *ctx, const char **vector)
+int allow_transports(struct command_context *ctx, const char * const *vector)
 {
        /* NOTE:  caller is required to provide only a list
         * of *valid* transport names
@@ -206,7 +206,7 @@ COMMAND_HELPER(transport_list_parse, char ***vector)
                return ERROR_COMMAND_SYNTAX_ERROR;
 
        /* our return vector must be NULL terminated */
-       argv = (char **) calloc(n + 1, sizeof(char *));
+       argv = calloc(n + 1, sizeof(char *));
        if (argv == NULL)
                return ERROR_FAIL;
 
@@ -239,12 +239,13 @@ COMMAND_HANDLER(handle_transport_init)
 {
        LOG_DEBUG("%s", __func__);
        if (!session) {
-               LOG_ERROR("session's transport is not selected.");
+               LOG_ERROR("session transport was not selected. Use 'transport select <transport>'");
 
                /* no session transport configured, print transports then fail */
-               const char **vector = allowed_transports;
+               LOG_ERROR("Transports available:");
+               const char * const *vector = allowed_transports;
                while (*vector) {
-                       LOG_ERROR("allow transport '%s'", *vector);
+                       LOG_ERROR("%s", *vector);
                        vector++;
                }
                return ERROR_FAIL;
@@ -274,21 +275,33 @@ COMMAND_HANDLER(handle_transport_list)
  */
 static int jim_transport_select(Jim_Interp *interp, int argc, Jim_Obj * const *argv)
 {
+       int res;
        switch (argc) {
-               case 1:         /* return/display */
+               case 1: /* autoselect if necessary, then return/display current config */
                        if (!session) {
-                               LOG_ERROR("session's transport is not selected.");
-                               return JIM_ERR;
-                       } else {
-                               Jim_SetResultString(interp, session->name, -1);
-                               return JIM_OK;
+                               if (!allowed_transports) {
+                                       LOG_ERROR("Debug adapter does not support any transports? Check config file order.");
+                                       return JIM_ERR;
+                               }
+                               LOG_INFO("auto-selecting first available session transport \"%s\". "
+                                        "To override use 'transport select <transport>'.", allowed_transports[0]);
+                               res = transport_select(global_cmd_ctx, allowed_transports[0]);
+                               if (res != JIM_OK)
+                                       return res;
                        }
+                       Jim_SetResultString(interp, session->name, -1);
+                       return JIM_OK;
                        break;
-               case 2:         /* assign */
+               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;
+                               if (!strcmp(session->name, argv[1]->bytes)) {
+                                       LOG_WARNING("Transport \"%s\" was already selected", session->name);
+                                       Jim_SetResultString(interp, session->name, -1);
+                                       return JIM_OK;
+                               } else {
+                                       LOG_ERROR("Can't change session's transport after the initial selection was made");
+                                       return JIM_ERR;
+                               }
                        }
 
                        /* Is this transport supported by our debug adapter?
@@ -304,8 +317,13 @@ static int jim_transport_select(Jim_Interp *interp, int argc, Jim_Obj * const *a
 
                        for (unsigned i = 0; allowed_transports[i]; i++) {
 
-                               if (strcmp(allowed_transports[i], argv[1]->bytes) == 0)
-                                       return transport_select(global_cmd_ctx, argv[1]->bytes);
+                               if (strcmp(allowed_transports[i], argv[1]->bytes) == 0) {
+                                       if (transport_select(global_cmd_ctx, argv[1]->bytes) == ERROR_OK) {
+                                               Jim_SetResultString(interp, session->name, -1);
+                                               return JIM_OK;
+                                       }
+                                       return JIM_ERR;
+                               }
                        }
 
                        LOG_ERROR("Debug adapter doesn't support '%s' transport", argv[1]->bytes);