From b55f4d2df21b966c3953264d8961f259814f4650 Mon Sep 17 00:00:00 2001
From: Neels Hofmeyr <neels@hofmeyr.de>
Date: Thu, 31 Jan 2019 08:13:31 +0100
Subject: vty: enable optional-multi-choice syntax: [(one|two)]

Since very recently we sensibly handle commands like

  cmd ([one]|[two]|[three])

as optional multi-choice arguments. In addition, support the more obvious
syntax of

  cmd [(one|two|three)]

Internally, the tokens are mangled to [one] [two] and [three], which is how the
rest of the code detects optional args, and makes sense in terms of UI:

  > cmd ?
  [one]
  [two]
  [three]

(i.e. optional arguments are always shown in braces in '?' listings)

Before this patch, commands defined with a syntax like [(one|two)], would lead
to an assertion (shows as "multiple") during program startup.

Change-Id: I952b3c00f97e2447f2308b0ec6f5f1714692b5b2
---
 src/vty/command.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

(limited to 'src')

diff --git a/src/vty/command.c b/src/vty/command.c
index 9d02d696..2242e761 100644
--- a/src/vty/command.c
+++ b/src/vty/command.c
@@ -380,6 +380,7 @@ static char *cmd_desc_str(const char **string)
 static vector cmd_make_descvec(const char *string, const char *descstr)
 {
 	int multiple = 0;
+	int optional_brace = 0;
 	const char *sp;
 	char *token;
 	int len;
@@ -401,6 +402,12 @@ static vector cmd_make_descvec(const char *string, const char *descstr)
 		while (isspace((int)*cp) && *cp != '\0')
 			cp++;
 
+		/* Explicitly detect optional multi-choice braces like [(one|two)]. */
+		if (cp[0] == '[' && cp[1] == '(') {
+			optional_brace = 1;
+			cp++;
+		}
+
 		if (*cp == '(') {
 			multiple = 1;
 			cp++;
@@ -408,6 +415,9 @@ static vector cmd_make_descvec(const char *string, const char *descstr)
 		if (*cp == ')') {
 			multiple = 0;
 			cp++;
+			if (*cp == ']')
+				cp++;
+			optional_brace = 0;
 		}
 		if (*cp == '|') {
 			OSMO_ASSERT(multiple);
@@ -434,9 +444,17 @@ static vector cmd_make_descvec(const char *string, const char *descstr)
 
 		len = cp - sp;
 
-		token = _talloc_zero(tall_vty_cmd_ctx, len + 1, "cmd_make_descvec");
-		memcpy(token, sp, len);
-		*(token + len) = '\0';
+		token = _talloc_zero(tall_vty_cmd_ctx, len + (optional_brace? 2 : 0) + 1, "cmd_make_descvec");
+		if (optional_brace) {
+			/* Place each individual multi-choice token in its own square braces */
+			token[0] = '[';
+			memcpy(token + 1, sp, len);
+			token[1 + len] = ']';
+			token[2 + len] = '\0';
+		} else {
+			memcpy(token, sp, len);
+			*(token + len) = '\0';
+		}
 
 		desc = talloc_zero(tall_vty_cmd_ctx, struct desc);
 		desc->cmd = token;
-- 
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