8:05 a.m.
Refactor the existing logic using two nested loops with a jump into the
middle of both with 3 separate places fetching next token to a single
loop using a state machine with one centralized place to fetch next
tokens and add explanation comments.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
tools/vsh.c | 336 ++++++++++++++++++++++++++++++++--------------------
1 file changed, 210 insertions(+), 126 deletions(-)
diff --git a/tools/vsh.c b/tools/vsh.c
index b04b4f5cd0..e0a04593b0 100644
--- a/tools/vsh.c
+++ b/tools/vsh.c
@@ -1476,171 +1476,255 @@ vshCmdNew(vshControl *ctl,
}
-static bool
-vshCommandParse(vshControl *ctl, vshCommandParser *parser, vshCmd **partial)
+static int
+vshCmdOptAssignPositional(vshControl *ctl,
+ vshCmd *cmd,
+ const char *val,
+ bool report)
{
- g_autoptr(vshCmd) cmd = NULL;
- char *tkdata = NULL;
- vshCmd *clast = NULL;
+ vshCmdOpt *opt;
- if (!partial) {
+ if (!(opt = vshCmdGetNextPositionalOpt(cmd))) {
+ /* ignore spurious arguments for 'help' command */
+ if (STREQ(cmd->def->name, "help"))
+ return 0;
+
+ if (report)
+ vshError(ctl, _("unexpected data '%1$s'"), val);
+
+ return -1;
+ }
+
+ vshCmdOptAssign(ctl, cmd, opt, val, report);
+ return 0;
+}
+
+
+typedef enum {
+ VSH_CMD_PARSER_STATE_START,
+ VSH_CMD_PARSER_STATE_COMMENT,
+ VSH_CMD_PARSER_STATE_COMMAND,
+ VSH_CMD_PARSER_STATE_ASSIGN_OPT,
+ VSH_CMD_PARSER_STATE_POSITIONAL_ONLY,
+} vshCommandParserState;
+
+static bool
+vshCommandParse(vshControl *ctl,
+ vshCommandParser *parser,
+ vshCmd **partial)
+{
+ g_autoptr(vshCmd) cmds = NULL; /* linked list of all parsed commands in this session
*/
+ vshCmd *cmds_last = NULL;
+ g_autoptr(vshCmd) cmd = NULL; /* currently parsed command */
+ vshCommandParserState state = VSH_CMD_PARSER_STATE_START;
+ vshCmdOpt *opt = NULL;
+ g_autofree char *optionvalue = NULL;
+ bool report = !partial;
+ bool ret = false;
+
+ if (partial) {
+ g_clear_pointer(partial, vshCommandFree);
+ } else {
g_clear_pointer(&ctl->cmd, vshCommandFree);
}
while (1) {
- vshCommandToken tk;
- bool data_only = false;
+ /* previous iteration might have already gotten a value. Store it as the
+ * token in this iteration */
+ g_autofree char *tkdata = g_steal_pointer(&optionvalue);
- if (partial) {
- g_clear_pointer(partial, vshCommandFree);
- }
-
- while (1) {
- vshCmdOpt *opt = NULL;
+ /* If we have a value already or the option to fill is a boolean we
+ * don't want to fetch a new token */
+ if (!(tkdata ||
+ (opt && opt->def->type == VSH_OT_BOOL))) {
+ vshCommandToken tk;
- tkdata = NULL;
- tk = parser->getNextArg(ctl, parser, &tkdata, true);
+ tk = parser->getNextArg(ctl, parser, &tkdata, report);
- if (tk == VSH_TK_ERROR)
- goto syntaxError;
- if (tk != VSH_TK_ARG) {
- VIR_FREE(tkdata);
+ switch (tk) {
+ case VSH_TK_ARG:
+ /* will be handled below */
break;
- }
- if (cmd == NULL) {
- /* first token must be command name or comment */
- if (*tkdata == '#') {
- do {
- VIR_FREE(tkdata);
- tk = parser->getNextArg(ctl, parser, &tkdata, false);
- } while (tk == VSH_TK_ARG);
- VIR_FREE(tkdata);
- break;
+ case VSH_TK_ERROR:
+ goto out;
+
+ case VSH_TK_END:
+ case VSH_TK_SUBCMD_END:
+ /* The last argument name expects a value, but it's missing */
+ if (opt) {
+ if (partial) {
+ /* for completion to work we need to also store the
+ * last token into the last 'opt' */
+ vshCmdOptAssign(ctl, cmd, opt, tkdata, report);
+ } else {
+ if (opt->def->type == VSH_OT_INT)
+ vshError(ctl, _("expected syntax: --%1$s
<number>"),
+ opt->def->name);
+ else
+ vshError(ctl, _("expected syntax: --%1$s
<string>"),
+ opt->def->name);
+
+ goto out;
+ }
}
- if (!(cmd = vshCmdNew(ctl, tkdata, !partial)))
- goto syntaxError;
-
- VIR_FREE(tkdata);
- } else if (data_only) {
- goto get_data;
- } else if (tkdata[0] == '-' && tkdata[1] == '-'
&&
- g_ascii_isalnum(tkdata[2])) {
- char *optstr = strchr(tkdata + 2, '=');
-
- if (optstr) {
- *optstr = '\0'; /* convert the '=' to '\0'
*/
- optstr = g_strdup(optstr + 1);
- }
+ /* command parsed -- allocate new struct for the command */
+ if (cmd) {
+ /* if we encountered --help, replace parsed command with 'help
<cmdname>' */
+ if (cmd->helpOptionSeen) {
+ vshCmd *helpcmd = vshCmdNewHelp(cmd->def->name);
- /* Special case 'help' to ignore all spurious options */
- if (!(opt = vshCmdGetOption(ctl, cmd, tkdata + 2,
- &optstr, partial == NULL))) {
- VIR_FREE(optstr);
- if (STREQ(cmd->def->name, "help"))
- continue;
- goto syntaxError;
- }
- VIR_FREE(tkdata);
-
- if (opt->def->type != VSH_OT_BOOL) {
- /* option data */
- if (optstr)
- tkdata = optstr;
- else
- tk = parser->getNextArg(ctl, parser, &tkdata, partial ==
NULL);
- if (tk == VSH_TK_ERROR)
- goto syntaxError;
- if (tk != VSH_TK_ARG) {
- if (partial) {
- vshCmdOptAssign(ctl, cmd, opt, tkdata, !partial);
- VIR_FREE(tkdata);
- } else {
- vshError(ctl,
- _("expected syntax: --%1$s
<%2$s>"),
- opt->def->name,
- opt->def->type ==
- VSH_OT_INT ? _("number") :
_("string"));
- }
- goto syntaxError;
- }
- } else {
- tkdata = NULL;
- if (optstr) {
- if (!partial)
- vshError(ctl, _("invalid '=' after option
--%1$s"),
- opt->def->name);
- VIR_FREE(optstr);
- goto syntaxError;
+ vshCommandFree(cmd);
+ cmd = helpcmd;
}
+
+ if (!partial &&
+ vshCommandCheckOpts(ctl, cmd) < 0)
+ goto out;
+
+ if (!cmds)
+ cmds = cmd;
+ if (cmds_last)
+ cmds_last->next = cmd;
+ cmds_last = g_steal_pointer(&cmd);
}
- } else if (tkdata[0] == '-' && tkdata[1] == '-'
&&
- tkdata[2] == '\0') {
- VIR_FREE(tkdata);
- data_only = true;
- continue;
- } else {
- get_data:
- /* Special case 'help' to ignore spurious data */
- if (!(opt = vshCmdGetNextPositionalOpt(cmd)) &&
- STRNEQ(cmd->def->name, "help")) {
- if (!partial)
- vshError(ctl, _("unexpected data '%1$s'"),
tkdata);
- goto syntaxError;
+
+
+ /* everything parsed */
+ if (tk == VSH_TK_END) {
+ ret = true;
+ goto out;
}
- }
- if (opt) {
- vshCmdOptAssign(ctl, cmd, opt, tkdata, !partial);
- VIR_FREE(tkdata);
+ /* after processing the command we need to start over again to
+ * fetch another token */
+ state = VSH_CMD_PARSER_STATE_START;
+ continue;
}
}
- /* command parsed -- allocate new struct for the command */
- if (cmd) {
- /* if we encountered --help, replace parsed command with 'help
<cmdname>' */
- if (cmd->helpOptionSeen) {
- vshCmd *helpcmd = vshCmdNewHelp(cmd->def->name);
+ /* at this point we know that @tkdata is an argument */
+ switch (state) {
+ case VSH_CMD_PARSER_STATE_START:
+ if (*tkdata == '#') {
+ state = VSH_CMD_PARSER_STATE_COMMENT;
+ } else {
+ state = VSH_CMD_PARSER_STATE_COMMAND;
+
+ if (!(cmd = vshCmdNew(ctl, tkdata, !partial)))
+ goto out;
+ }
+
+ break;
+
+ case VSH_CMD_PARSER_STATE_COMMENT:
+ /* continue eating tokens until end of line or end of input */
+ state = VSH_CMD_PARSER_STATE_COMMENT;
+ break;
+
+ case VSH_CMD_PARSER_STATE_COMMAND: {
+ /* parsing individual options for the command. There are following options:
+ * --option
+ * --option value
+ * --option=value
+ * --aliasoptionwithvalue (value is part of the alias definition)
+ * value
+ * -- (terminate accepting '--option', fill only positional args)
+ */
+ const char *optionname = tkdata + 2;
+ char *sep;
- vshCommandFree(cmd);
- cmd = helpcmd;
+ if (!STRPREFIX(tkdata, "--")) {
+ if (vshCmdOptAssignPositional(ctl, cmd, tkdata, report) < 0)
+ goto out;
+ break;
}
- if (!partial &&
- vshCommandCheckOpts(ctl, cmd) < 0) {
- vshCommandFree(cmd);
- goto syntaxError;
+ if (STREQ(tkdata, "--")) {
+ state = VSH_CMD_PARSER_STATE_POSITIONAL_ONLY;
+ break;
+ }
+
+ if ((sep = strchr(optionname, '='))) {
+ *(sep++) = '\0';
+
+ /* 'optionvalue' has lifetime until next iteration */
+ optionvalue = g_strdup(sep);
}
- if (partial) {
- vshCommandFree(*partial);
- *partial = g_steal_pointer(&cmd);
+ /* lookup the option. Note that vshCmdGetOption also resolves aliases
+ * and thus the value possibly contained in the alias */
+ if (!(opt = vshCmdGetOption(ctl, cmd, optionname, &optionvalue, report)))
{
+ if (STRNEQ(cmd->def->name, "help"))
+ goto out;
+
+ /* ignore spurious arguments for 'help' command */
+ g_clear_pointer(&optionvalue, g_free);
+ state = VSH_CMD_PARSER_STATE_COMMAND;
} else {
- if (!ctl->cmd)
- ctl->cmd = cmd;
- if (clast)
- clast->next = cmd;
- clast = g_steal_pointer(&cmd);
+ state = VSH_CMD_PARSER_STATE_ASSIGN_OPT;
}
}
+ break;
+
+ case VSH_CMD_PARSER_STATE_ASSIGN_OPT:
+ /* Parameter for a boolean was passed via --boolopt=val */
+ if (tkdata && opt->def->type == VSH_OT_BOOL) {
+ if (report)
+ vshError(ctl, _("invalid '=' after option
--%1$s"),
+ opt->def->name);
+ goto out;
+ }
- if (tk == VSH_TK_END)
+ vshCmdOptAssign(ctl, cmd, opt, tkdata, report);
+ opt = NULL;
+ state = VSH_CMD_PARSER_STATE_COMMAND;
break;
+
+ case VSH_CMD_PARSER_STATE_POSITIONAL_ONLY:
+ state = VSH_CMD_PARSER_STATE_POSITIONAL_ONLY;
+
+ if (vshCmdOptAssignPositional(ctl, cmd, tkdata, report) < 0)
+ goto out;
+ break;
+ }
}
- return true;
+ out:
- syntaxError:
if (partial) {
- *partial = g_steal_pointer(&cmd);
+ /* When parsing a command for command completion, the last processed
+ * command or the one being currently parsed */
+ if (cmd) {
+ *partial = g_steal_pointer(&cmd);
+ } else if (cmds == cmds_last) {
+ *partial = g_steal_pointer(&cmds);
+ } else {
+ /* break the last command out of the linked list and let the rest be freed
*/
+ vshCmd *nc;
+
+ for (nc = cmds; nc; nc = nc->next) {
+ if (nc->next == cmds_last) {
+ nc->next = NULL;
+ break;
+ }
+ }
+
+ *partial = cmds_last;
+ }
} else {
- g_clear_pointer(&ctl->cmd, vshCommandFree);
+ /* for normal command parsing use the whole parsed command list, but
+ * only on success */
+ if (ret == true) {
+ ctl->cmd = g_steal_pointer(&cmds);
+ }
}
- VIR_FREE(tkdata);
- return false;
+
+ return ret;
}
+
/* --------------------
* Command argv parsing
* --------------------
--
2.44.0