command context: fix errors when running certain commands on startup

Various commands, e.g. "arm mcr xxxx" would fail if invoked upon startup
since it there was no command context defined for the jim interpreter
in that case.

A Jim interpreter is now associated with a command context(telnet,
gdb server's) or the default global command context.

Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

5 files changed, 30 insertions, 23 deletions

diff --git a/src/helper/command.c b/src/helper/command.c
index 3625508f..be262f2e 100644
--- a/src/helper/command.c
+++ b/src/helper/command.c
@@ -167,14 +167,18 @@ static const char **script_command_args_alloc(
 	return words;
 }
 
-static struct command_context *current_command_context(Jim_Interp *interp)
+struct command_context *current_command_context(Jim_Interp *interp)
 {
 	/* grab the command context from the associated data */
 	struct command_context *cmd_ctx = Jim_GetAssocData(interp, "context");
 	if (NULL == cmd_ctx)
 	{
 		/* Tcl can invoke commands directly instead of via command_run_line(). This would
-		 * happen when the Jim Tcl interpreter is provided by eCos.
+		 * happen when the Jim Tcl interpreter is provided by eCos or if we are running
+		 * commands in a startup script.
+		 *
+		 * A telnet or gdb server would provide a non-default command context to
+		 * handle piping of error output, have a separate current target, etc.
 		 */
 		cmd_ctx = global_cmd_ctx;
 	}
diff --git a/src/helper/command.h b/src/helper/command.h
index 8a418d36..2c192416 100644
--- a/src/helper/command.h
+++ b/src/helper/command.h
@@ -311,6 +311,10 @@ void command_set_output_handler(struct command_context* context,
 
 int command_context_mode(struct command_context *context, enum command_mode mode);
 
+/* Return the current command context associated with the Jim interpreter or
+ * alternatively the global default command interpreter
+ */
+struct command_context *current_command_context(Jim_Interp *interp);
 /**
  * Creates a new command context using the startup TCL provided and
  * the existing Jim interpreter, if any. If interp == NULL, then command_init
diff --git a/src/jtag/tcl.c b/src/jtag/tcl.c
index 579ca9e5..ea6d07e3 100644
--- a/src/jtag/tcl.c
+++ b/src/jtag/tcl.c
@@ -684,7 +684,7 @@ static int jim_jtag_arp_init(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 		Jim_WrongNumArgs(goi.interp, 1, goi.argv-1, "(no params)");
 		return JIM_ERR;
 	}
-	struct command_context *context = Jim_GetAssocData(interp, "context");
+	struct command_context *context = current_command_context(interp);
 	int e = jtag_init_inner(context);
 	if (e != ERROR_OK) {
 		Jim_SetResult_sprintf(goi.interp, "error: %d", e);
@@ -701,7 +701,7 @@ static int jim_jtag_arp_init_reset(Jim_Interp *interp, int argc, Jim_Obj *const
 		Jim_WrongNumArgs(goi.interp, 1, goi.argv-1, "(no params)");
 		return JIM_ERR;
 	}
-	struct command_context *context = Jim_GetAssocData(interp, "context");
+	struct command_context *context = current_command_context(interp);
 	int e = jtag_init_reset(context);
 	if (e != ERROR_OK) {
 		Jim_SetResult_sprintf(goi.interp, "error: %d", e);
diff --git a/src/target/armv4_5.c b/src/target/armv4_5.c
index eeb6694c..1a84a5f4 100644
--- a/src/target/armv4_5.c
+++ b/src/target/armv4_5.c
@@ -820,11 +820,9 @@ static int jim_mcrmrc(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 	struct arm *arm;
 	int retval;
 
-	context = Jim_GetAssocData(interp, "context");
-	if (context == NULL) {
-		LOG_ERROR("%s: no command context", __func__);
-		return JIM_ERR;
-	}
+	context = current_command_context(interp);
+	assert( context != NULL);
+
 	target = get_current_target(context);
 	if (target == NULL) {
 		LOG_ERROR("%s: no current target", __func__);
diff --git a/src/target/target.c b/src/target/target.c
index a3a1b0ad..d17bb744 100644
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -3236,12 +3236,9 @@ static int jim_mem2array(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 	struct command_context *context;
 	struct target *target;
 
-	context = Jim_GetAssocData(interp, "context");
-	if (context == NULL)
-	{
-		LOG_ERROR("mem2array: no command context");
-		return JIM_ERR;
-	}
+	context = current_command_context(interp);
+	assert (context != NULL);
+
 	target = get_current_target(context);
 	if (target == NULL)
 	{
@@ -3432,11 +3429,9 @@ static int jim_array2mem(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 	struct command_context *context;
 	struct target *target;
 
-	context = Jim_GetAssocData(interp, "context");
-	if (context == NULL) {
-		LOG_ERROR("array2mem: no command context");
-		return JIM_ERR;
-	}
+	context = current_command_context(interp);
+	assert (context != NULL);
+
 	target = get_current_target(context);
 	if (target == NULL) {
 		LOG_ERROR("array2mem: no current target");
@@ -4318,7 +4313,9 @@ static int jim_target_wait_state(Jim_Interp *interp, int argc, Jim_Obj *const *a
  */
 static int jim_target_event_list(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
-	struct command_context *cmd_ctx = Jim_GetAssocData(interp, "context");
+	struct command_context *cmd_ctx = current_command_context(interp);
+	assert (cmd_ctx != NULL);
+
 	struct target *target = Jim_CmdPrivData(interp);
 	struct target_event_action *teap = target->event_action;
 	command_print(cmd_ctx, "Event actions for target (%d) %s\n",
@@ -4512,7 +4509,9 @@ static int target_create(Jim_GetOptInfo *goi)
 	struct target *target;
 	struct command_context *cmd_ctx;
 
-	cmd_ctx = Jim_GetAssocData(goi->interp, "context");
+	cmd_ctx = current_command_context(goi->interp);
+	assert (cmd_ctx != NULL);
+
 	if (goi->argc < 3) {
 		Jim_WrongNumArgs(goi->interp, 1, goi->argv, "?name? ?type? ..options...");
 		return JIM_ERR;
@@ -4686,7 +4685,9 @@ static int jim_target_current(Jim_Interp *interp, int argc, Jim_Obj *const *argv
 		Jim_WrongNumArgs(interp, 1, argv, "Too many parameters");
 		return JIM_ERR;
 	}
-	struct command_context *cmd_ctx = Jim_GetAssocData(interp, "context");
+	struct command_context *cmd_ctx = current_command_context(interp);
+	assert (cmd_ctx != NULL);
+
 	Jim_SetResultString(interp, get_current_target(cmd_ctx)->cmd_name, -1);
 	return JIM_OK;
 }