linux-user: Fix layout of usage table to account for option text

The linux-user usage message attempts to line up the columns in
its table by calculating the maximum width of any item in them.
However for the 'Argument' column it was only accounting for the
length of the option switch (eg "-d"), not the additional example
text (eg "item[,...]"). This currently has no adverse effects
because the widest item in the column happens to be the argumentless
"-singlestep" option, but improving the "-d" option help to read
"-d item[,...]" exceeds that limit.

Fix this by correctly calculating maxarglen as the width of the
first column text including a possible option argument, and
adjusting its uses to match.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

diff --git a/linux-user/main.c b/linux-user/main.c
index d8b0cd65fa71a48b55c00bb5cbf59c321f065a85..4e92a0b4c5e4c195269df8976b7e5043121740c5 100644 (file)
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -3406,27 +3406,35 @@ static void usage(void)
            "Options and associated environment variables:\n"
            "\n");
 
-    maxarglen = maxenvlen = 0;
+    /* Calculate column widths. We must always have at least enough space
+     * for the column header.
+     */
+    maxarglen = strlen("Argument");
+    maxenvlen = strlen("Env-variable");
 
     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
+        int arglen = strlen(arginfo->argv);
+        if (arginfo->has_arg) {
+            arglen += strlen(arginfo->example) + 1;
+        }
         if (strlen(arginfo->env) > maxenvlen) {
             maxenvlen = strlen(arginfo->env);
         }
-        if (strlen(arginfo->argv) > maxarglen) {
-            maxarglen = strlen(arginfo->argv);
+        if (arglen > maxarglen) {
+            maxarglen = arglen;
         }
     }
 
-    printf("%-*s%-*sDescription\n", maxarglen+3, "Argument",
-            maxenvlen+1, "Env-variable");
+    printf("%-*s %-*s Description\n", maxarglen+1, "Argument",
+            maxenvlen, "Env-variable");
 
     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
         if (arginfo->has_arg) {
             printf("-%s %-*s %-*s %s\n", arginfo->argv,
-                    (int)(maxarglen-strlen(arginfo->argv)), arginfo->example,
-                    maxenvlen, arginfo->env, arginfo->help);
+                   (int)(maxarglen - strlen(arginfo->argv) - 1),
+                   arginfo->example, maxenvlen, arginfo->env, arginfo->help);
         } else {
-            printf("-%-*s %-*s %s\n", maxarglen+1, arginfo->argv,
+            printf("-%-*s %-*s %s\n", maxarglen, arginfo->argv,
                     maxenvlen, arginfo->env,
                     arginfo->help);
         }