cmdutils: split per-option code out of parse_options().

This allows options like -target, which are just shortcuts for other
options, to work without dummy function for all options they invoke.

cmdutils.c

@@ -203,29 +203,12 @@ static inline void prepare_app_arguments(int *argc_ptr, char ***argv_ptr)
 }
 #endif /* WIN32 && !__MINGW32CE__ */
 
-void parse_options(void *optctx, int argc, char **argv, const OptionDef *options,
+int parse_option(void *optctx, const char *opt, const char *arg, const OptionDef *options)
-                   void (* parse_arg_function)(void *, const char*))
 {
-    const char *opt, *arg;
-    int optindex, handleoptions=1;
     const OptionDef *po;
-
-    /* perform system-dependent conversions for arguments list */
-    prepare_app_arguments(&argc, &argv);
-
-    /* parse options */
-    optindex = 1;
-    while (optindex < argc) {
-        void *dst;
-        opt = argv[optindex++];
-
-        if (handleoptions && opt[0] == '-' && opt[1] != '\0') {
     int bool_val = 1;
-            if (opt[1] == '-' && opt[2] == '\0') {
+    void *dst;
-                handleoptions = 0;
+
-                continue;
-            }
-            opt++;
     po = find_option(options, opt);
     if (!po->name && opt[0] == 'n' && opt[1] == 'o') {
         /* handle 'no' bool option */
@@ -238,20 +221,18 @@ void parse_options(void *optctx, int argc, char **argv, const OptionDef *options
         po = find_option(options, "default");
     if (!po->name) {
 unknown_opt:
-                fprintf(stderr, "%s: unrecognized option '%s'\n", argv[0], opt);
+        av_log(NULL, AV_LOG_ERROR, "Unrecognized option '%s'\n", opt);
-                exit_program(1);
+        return AVERROR(EINVAL);
-            }
-            arg = NULL;
-            if (po->flags & HAS_ARG) {
-                arg = argv[optindex++];
-                if (!arg) {
-                    fprintf(stderr, "%s: missing argument for option '%s'\n", argv[0], opt);
-                    exit_program(1);
     }
+    if (po->flags & HAS_ARG && !arg) {
+        av_log(NULL, AV_LOG_ERROR, "Missing argument for option '%s'\n", opt);
+        return AVERROR(EINVAL);
     }
+
     /* new-style options contain an offset into optctx, old-style address of
      * a global var*/
-            dst = po->flags & OPT_OFFSET ? (uint8_t*)optctx + po->u.off : po->u.dst_ptr;
+    dst = po->flags & (OPT_OFFSET) ? (uint8_t*)optctx + po->u.off : po->u.dst_ptr;
+
     if (po->flags & OPT_STRING) {
         char *str;
         str = av_strdup(arg);
@@ -268,12 +249,39 @@ unknown_opt:
         int ret = po->flags & OPT_FUNC2 ? po->u.func2_arg(optctx, opt, arg) :
                                           po->u.func_arg(opt, arg);
         if (ret < 0) {
-                    fprintf(stderr, "%s: failed to set value '%s' for option '%s'\n", argv[0], arg, opt);
+            av_log(NULL, AV_LOG_ERROR, "Failed to set value '%s' for option '%s'\n", arg, opt);
-                    exit_program(1);
+            return ret;
         }
     }
     if (po->flags & OPT_EXIT)
         exit_program(0);
+    return !!(po->flags & HAS_ARG);
+}
+
+void parse_options(void *optctx, int argc, char **argv, const OptionDef *options,
+                   void (* parse_arg_function)(void *, const char*))
+{
+    const char *opt;
+    int optindex, handleoptions = 1, ret;
+
+    /* perform system-dependent conversions for arguments list */
+    prepare_app_arguments(&argc, &argv);
+
+    /* parse options */
+    optindex = 1;
+    while (optindex < argc) {
+        opt = argv[optindex++];
+
+        if (handleoptions && opt[0] == '-' && opt[1] != '\0') {
+            if (opt[1] == '-' && opt[2] == '\0') {
+                handleoptions = 0;
+                continue;
+            }
+            opt++;
+
+            if ((ret = parse_option(optctx, opt, argv[optindex], options)) < 0)
+                exit_program(1);
+            optindex += ret;
         } else {
             if (parse_arg_function)
                 parse_arg_function(optctx, opt);

cmdutils.h

@@ -151,6 +151,13 @@ void show_help_options(const OptionDef *options, const char *msg, int mask, int
 void parse_options(void *optctx, int argc, char **argv, const OptionDef *options,
                    void (* parse_arg_function)(void *optctx, const char*));
 
+/**
+ * Parse one given option.
+ *
+ * @return on success 1 if arg was consumed, 0 otherwise; negative number on error
+ */
+int parse_option(void *optctx, const char *opt, const char *arg, const OptionDef *options);
+
 /**
  * Check if the given stream matches a stream specifier.
  *