virsh: Add option to suppress error in various functions

A bool 'report' has been introduced in various functions, which when set
to true will produce the error it is suppposed to produce, and when
false, will suppress the error. These functions are used in the next
patch for auto-completion.
Signed-off-by: NNishith Shah <nishithshah.2211@gmail.com>

tools/vsh.c

@@ -434,7 +434,8 @@ static vshCmdOptDef helpopt = {
 };
 static const vshCmdOptDef *
 vshCmddefGetOption(vshControl *ctl, const vshCmdDef *cmd, const char *name,
-                   uint64_t *opts_seen, int *opt_index, char **optstr)
+                   uint64_t *opts_seen, int *opt_index, char **optstr,
+                   bool report)
 {
     size_t i;
     const vshCmdOptDef *ret = NULL;
@@ -461,8 +462,9 @@ vshCmddefGetOption(vshControl *ctl, const vshCmdDef *cmd, const char *name,
                 if ((value = strchr(name, '='))) {
                     *value = '\0';
                     if (*optstr) {
-                        vshError(ctl, _("invalid '=' after option --%s"),
-                                 opt->name);
+                        if (report)
+                            vshError(ctl, _("invalid '=' after option --%s"),
+                                     opt->name);
                         goto cleanup;
                     }
                     if (VIR_STRDUP(*optstr, value + 1) < 0)
@@ -471,7 +473,8 @@ vshCmddefGetOption(vshControl *ctl, const vshCmdDef *cmd, const char *name,
                 continue;
             }
             if ((*opts_seen & (1ULL << i)) && opt->type != VSH_OT_ARGV) {
-                vshError(ctl, _("option --%s already seen"), name);
+                if (report)
+                    vshError(ctl, _("option --%s already seen"), name);
                 goto cleanup;
             }
             *opts_seen |= 1ULL << i;
@@ -481,7 +484,7 @@ vshCmddefGetOption(vshControl *ctl, const vshCmdDef *cmd, const char *name,
         }
     }
 
-    if (STRNEQ(cmd->name, "help")) {
+    if (STRNEQ(cmd->name, "help") && report) {
         vshError(ctl, _("command '%s' doesn't support option --%s"),
                  cmd->name, name);
     }
@@ -1352,7 +1355,7 @@ typedef enum {
 typedef struct _vshCommandParser vshCommandParser;
 struct _vshCommandParser {
     vshCommandToken(*getNextArg)(vshControl *, vshCommandParser *,
-                                 char **);
+                                 char **, bool);
     /* vshCommandStringGetArg() */
     char *pos;
     /* vshCommandArgvGetArg() */
@@ -1387,7 +1390,7 @@ vshCommandParse(vshControl *ctl, vshCommandParser *parser)
             const vshCmdOptDef *opt = NULL;
 
             tkdata = NULL;
-            tk = parser->getNextArg(ctl, parser, &tkdata);
+            tk = parser->getNextArg(ctl, parser, &tkdata, true);
 
             if (tk == VSH_TK_ERROR)
                 goto syntaxError;
@@ -1424,7 +1427,7 @@ vshCommandParse(vshControl *ctl, vshCommandParser *parser)
                 /* Special case 'help' to ignore all spurious options */
                 if (!(opt = vshCmddefGetOption(ctl, cmd, tkdata + 2,
                                                &opts_seen, &opt_index,
-                                               &optstr))) {
+                                               &optstr, true))) {
                     VIR_FREE(optstr);
                     if (STREQ(cmd->name, "help"))
                         continue;
@@ -1437,7 +1440,7 @@ vshCommandParse(vshControl *ctl, vshCommandParser *parser)
                     if (optstr)
                         tkdata = optstr;
                     else
-                        tk = parser->getNextArg(ctl, parser, &tkdata);
+                        tk = parser->getNextArg(ctl, parser, &tkdata, true);
                     if (tk == VSH_TK_ERROR)
                         goto syntaxError;
                     if (tk != VSH_TK_ARG) {
@@ -1559,7 +1562,8 @@ vshCommandParse(vshControl *ctl, vshCommandParser *parser)
  */
 
 static vshCommandToken ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
-vshCommandArgvGetArg(vshControl *ctl, vshCommandParser *parser, char **res)
+vshCommandArgvGetArg(vshControl *ctl, vshCommandParser *parser, char **res,
+                     bool report ATTRIBUTE_UNUSED)
 {
     if (parser->arg_pos == parser->arg_end) {
         *res = NULL;
@@ -1591,7 +1595,8 @@ vshCommandArgvParse(vshControl *ctl, int nargs, char **argv)
  */
 
 static vshCommandToken ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
-vshCommandStringGetArg(vshControl *ctl, vshCommandParser *parser, char **res)
+vshCommandStringGetArg(vshControl *ctl, vshCommandParser *parser, char **res,
+                       bool report)
 {
     bool single_quote = false;
     bool double_quote = false;
@@ -1628,7 +1633,8 @@ vshCommandStringGetArg(vshControl *ctl, vshCommandParser *parser, char **res)
              */
             p++;
             if (*p == '\0') {
-                vshError(ctl, "%s", _("dangling \\"));
+                if (report)
+                    vshError(ctl, "%s", _("dangling \\"));
                 return VSH_TK_ERROR;
             }
         } else if (!single_quote && *p == '"') { /* double quote */
@@ -1641,7 +1647,8 @@ vshCommandStringGetArg(vshControl *ctl, vshCommandParser *parser, char **res)
         sz++;
     }
     if (double_quote) {
-        vshError(ctl, "%s", _("missing \""));
+        if (report)
+            vshError(ctl, "%s", _("missing \""));
         return VSH_TK_ERROR;
     }