[Qemu-devel] [RFC PATCH 2/3] implement -readconfig help=defconfig option

[Eduardo Habkost <ehabkost@redhat.com>]

This method will list the paths of all default config files.

This is where the placement of qemu_read_config_arg() on
qemu-config-arch.c becomes necessary: we have to use the list of config
files to implement the new help option.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 qemu-config-arch.c |   27 ++++++++++++++++++++++++++-
 1 files changed, 26 insertions(+), 1 deletions(-)

diff --git a/qemu-config-arch.c b/qemu-config-arch.c
index 83a0c89..832f0b0 100644
--- a/qemu-config-arch.c
+++ b/qemu-config-arch.c
@@ -41,6 +41,10 @@ static QemuOptsList qemu_readconfig_opts = {
             .name = "fd",
             .type = QEMU_OPT_NUMBER,
         },
+        {
+            .name = "help",
+            .type = QEMU_OPT_STRING,
+        },
         { /*End of list */ }
     },
 };
@@ -70,6 +74,22 @@ static struct DefaultConfigFile arch_default_configs[] = {
     {NULL, NULL},
 };
 
+/* print -readconfig help information
+ */
+static void readconfig_help(const char *arg)
+{
+    if (!strcmp(arg, "defconfig")) {
+        const struct DefaultConfigFile *cfg;
+        printf("Default config files:\n");
+        for (cfg = arch_default_configs; cfg->path; cfg++) {
+            printf("\t%s:\t%s\n", cfg->type, cfg->path);
+        }
+    } else {
+        fprintf(stderr, "Invalid readconfig help option: %s\n", arg);
+        exit(1);
+    }
+}
+
 /* Read Qemu config file based on parsed QemuOpts object
  *
  * Returns 0 on success, -errno on failure.
@@ -79,12 +99,17 @@ static int qemu_read_config_opts(QemuOpts *opts)
     int fd = -1;
     uint64_t fd_arg = qemu_opt_get_number(opts, "fd", (uint64_t)-1);
     const char *path = qemu_opt_get(opts, "path");
+    const char *help = qemu_opt_get(opts, "help");
+
 
     if (fd_arg != (uint64_t)-1) {
         fd = fd_arg;
     }
 
-    if (path) {
+    if (help) {
+        readconfig_help(help);
+        exit(0);
+    } else if (path) {
         return qemu_read_config_filename(path);
     } else if (fd >= 0) {
         return qemu_read_config_fd(fd);
-- 
1.7.3.2