helper: fix flaky capture command

capture of progress output would get polling
results. This will break in the example below
where polling output would override the tcl
return value.

capture {sleep 10000; set abc def}

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

diff --git a/src/helper/command.c b/src/helper/command.c
index 086b03d3e0b068ade1175f1e2346b700da88ec23..1bd8c42912656e263a792817fc8b5752db00b62e 100644 (file)
--- a/src/helper/command.c
+++ b/src/helper/command.c
@@ -36,6 +36,7 @@
 #endif
 
 // @todo the inclusion of target.h here is a layering violation
+#include <jtag/jtag.h>
 #include <target/target.h>
 #include "command.h"
 #include "configuration.h"
@@ -867,6 +868,9 @@ static char* openocd_jim_fgets(char *s, int size, void *cookie)
        return NULL;
 }
 
+/* Capture progress output and return as tcl return value. If the
+ * progress output was empty, return tcl return value.
+ */
 static int jim_capture(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
        if (argc != 2)
@@ -874,9 +878,21 @@ static int jim_capture(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 
        struct log_capture_state *state = command_log_capture_start(interp);
 
+       /* disable polling during capture. This avoids capturing output
+        * from polling.
+        *
+        * This is necessary in order to avoid accidentially getting a non-empty
+        * string for tcl fn's.
+        */
+       bool save_poll = jtag_poll_get_enabled();
+
+       jtag_poll_set_enabled(false);
+
        const char *str = Jim_GetString(argv[1], NULL);
        int retcode = Jim_Eval_Named(interp, str, __THIS__FILE__, __LINE__);
 
+       jtag_poll_set_enabled(save_poll);
+
        command_log_capture_finish(state);
 
        return retcode;