test: (test_mkfds) add -O option for describing output values

Some factories prints some extra values in addition to the pid of
the process opening file descriptors.

Unlike parameters, test_mkfds didn't provide the way to explain
the extra values. The new option --output-values/-O provies it.

Example output:

  $ ./test_mkfds -O eventfd
  NTH DESCRIPTION
  0 the pid owning the file descriptor(s)
  1 the pid of child process

  $ ./test_mkfds -O cdev-tun
  NTH DESCRIPTION
  0 the pid owning the file descriptor(s)
  1 the network device name

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

diff --git a/tests/helpers/test_mkfds.c b/tests/helpers/test_mkfds.c
index b7f120a2c8eefdacc42ddb4248b03904b1203853..fc12561b0876b42e251817e68fd34c8071ebeeec 100644 (file)
--- a/tests/helpers/test_mkfds.c
+++ b/tests/helpers/test_mkfds.c
@@ -89,6 +89,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out, int status)
        fputs(" -a, --is-available <factory>  exit 0 if the factory is available\n", out);
        fputs(" -l, --list                    list available file descriptor factories and exit\n", out);
        fputs(" -I, --parameters <factory>    list parameters the factory takes\n", out);
+       fputs(" -O, --output-values <factory> list output values the factory prints\n", out);
        fputs(" -r, --comm <name>             rename self\n", out);
        fputs(" -q, --quiet                   don't print pid(s)\n", out);
        fputs(" -X, --dont-monitor-stdin      don't monitor stdin when pausing\n", out);
@@ -329,11 +330,14 @@ struct factory {
 #define MAX_N 13
        int  N;                 /* the number of fds this factory makes */
        int  EX_N;              /* fds made optionally */
-       int  EX_R;              /* the number of extra words printed to stdout. */
+       int  EX_O;              /* the number of extra words printed to stdout. */
        void *(*make)(const struct factory *, struct fdesc[], int, char **);
        void (*free)(const struct factory *, void *);
        void (*report)(const struct factory *, int, void *, FILE *);
        const struct parameter * params;
+       const char **o_descs;   /* string array describing values printed
+                                * to stdout. Used in -O option.
+                                * EX_O elements are expected. */
 };
 
 static void close_fdesc(int fd, void *data _U_)
@@ -4077,13 +4081,16 @@ static const struct factory factories[] = {
                .priv = false,
                .N    = 2,
                .EX_N = 0,
-               .EX_R = 1,
+               .EX_O = 1,
                .make = make_eventfd,
                .report = report_eventfd,
                .free = free_eventfd,
                .params = (struct parameter []) {
                        PARAM_END
-               }
+               },
+               .o_descs = (const char *[]){
+                       "the pid of child process",
+               },
        },
        {
                .name = "mqueue",
@@ -4091,7 +4098,7 @@ static const struct factory factories[] = {
                .priv = false,
                .N    = 2,
                .EX_N = 0,
-               .EX_R = 1,
+               .EX_O = 1,
                .make = make_mqueue,
                .report = report_mqueue,
                .free = free_mqueue,
@@ -4103,7 +4110,10 @@ static const struct factory factories[] = {
                                .defv.string = "/test_mkfds-mqueue",
                        },
                        PARAM_END
-               }
+               },
+               .o_descs = (const char *[]){
+                       "the pid of the child process",
+               },
        },
        {
                .name = "sysvshm",
@@ -4187,13 +4197,16 @@ static const struct factory factories[] = {
                .priv = true,
                .N    = 1,
                .EX_N = 0,
-               .EX_R = 1,
+               .EX_O = 1,
                .make = make_cdev_tun,
                .report = report_cdev_tun,
                .free = free_cdev_tun,
                .params = (struct parameter []) {
                        PARAM_END
-               }
+               },
+               .o_descs = (const char *[]){
+                       "the network device name",
+               },
        },
        {
                .name = "bpf-prog",
@@ -4258,13 +4271,16 @@ static const struct factory factories[] = {
                .priv = false,
                .N = 2,
                .EX_N = 0,
-               .EX_R = 1,
+               .EX_O = 1,
                .make = make_pty,
                .report = report_pty,
                .free = free_pty,
                .params = (struct parameter []) {
                        PARAM_END
-               }
+               },
+               .o_descs = (const char *[]){
+                       "the index of the slave device",
+               },
        },
        {
                .name = "mmap",
@@ -4332,7 +4348,7 @@ static void print_factory(const struct factory *factory)
               factory->name,
               factory->priv? "yes": "no",
               factory->N,
-              factory->EX_R + 1,
+              factory->EX_O + 1,
               count_parameters(factory),
               factory->desc);
 }
@@ -4371,6 +4387,25 @@ static void list_parameters(const char *factory_name)
        }
 }
 
+static void list_output_values(const char *factory_name)
+{
+       const struct factory *factory = find_factory(factory_name);
+       const char *fmt = "%3d %s\n";
+       const char **o;
+
+       if (!factory)
+               errx(EXIT_FAILURE, "no such factory: %s", factory_name);
+
+       printf("%-3s %s\n", "NTH", "DESCRIPTION");
+       printf(fmt, 0, "the pid owning the file descriptor(s)");
+
+       o  = factory->o_descs;
+       if (!o)
+               return;
+       for (int i = 0; i < factory->EX_O; i++)
+               printf(fmt, i + 1, *o);
+}
+
 static void rename_self(const char *comm)
 {
        if (prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0) < 0)
@@ -4555,6 +4590,7 @@ int main(int argc, char **argv)
                { "is-available",required_argument,NULL, 'a' },
                { "list",       no_argument, NULL, 'l' },
                { "parameters", required_argument, NULL, 'I' },
+               { "output-values", required_argument, NULL, 'O' },
                { "comm",       required_argument, NULL, 'r' },
                { "quiet",      no_argument, NULL, 'q' },
                { "dont-monitor-stdin", no_argument, NULL, 'X' },
@@ -4565,7 +4601,7 @@ int main(int argc, char **argv)
                { NULL, 0, NULL, 0 },
        };
 
-       while ((c = getopt_long(argc, argv, "a:lhqcI:r:w:WX", longopts, NULL)) != -1) {
+       while ((c = getopt_long(argc, argv, "a:lhqcI:O:r:w:WX", longopts, NULL)) != -1) {
                switch (c) {
                case 'h':
                        usage(stdout, EXIT_SUCCESS);
@@ -4577,6 +4613,9 @@ int main(int argc, char **argv)
                case 'I':
                        list_parameters(optarg);
                        exit(EXIT_SUCCESS);
+               case 'O':
+                       list_output_values(optarg);
+                       exit(EXIT_SUCCESS);
                case 'q':
                        quiet = true;
                        break;
@@ -4657,7 +4696,7 @@ int main(int argc, char **argv)
        if (!quiet) {
                printf("%d", getpid());
                if (factory->report) {
-                       for (int i = 0; i < factory->EX_R; i++) {
+                       for (int i = 0; i < factory->EX_O; i++) {
                                putchar(' ');
                                factory->report(factory, i, data, stdout);
                        }