utils: Move functions from debug.* to u_debug.*

Add unit tests for debug_get_bool_option and debug_get_num_option
Merge env_var_as_boolean and debug_get_bool_option and implement
 env_var_as_boolean with debug_get_bool_option in a stricter side.
Merge env_var_as_unsigned and debug_get_num_option and implement
 env_var_as_unsigned with debug_get_num_option in a stricter side.
Move debug_control, parse_debug_string, parse_enable_string,
 comma_separated_list_contains from debug.* to u_debug.*

Main changes:
os_get_option() is used instead of getenv() for env_var_as_boolean
 and env_var_as_unsigned;
also debug_get_bool_option() has logic like "true" always if not "false";
env_var_as_boolean() now uses different logic:
 if env variable is neither "true" nor "false" returns the default value,
 we left the second one; but if you want the behavior to be the same as in
 the old version of debug_get_bool_option() use dfault=true

Signed-off-by: Illia Abernikhin <illia.abernikhin@globallogic.com>
Reviewed-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19336>

src/util/u_debug.c

@@ -154,6 +154,12 @@ debug_get_option(const char *name, const char *dfault)
 }
 
 
+/**
+ * Reads an environment variable and interprets its value as a boolean.
+ * Recognizes 0/n/no/f/false case insensitive as false.
+ * Recognizes 1/y/yes/t/true case insensitive as true.
+ * Other values result in the default value.
+ */
 bool
 debug_get_bool_option(const char *name, bool dfault)
 {
@@ -162,22 +168,28 @@ debug_get_bool_option(const char *name, bool dfault)
 
    if (str == NULL)
       result = dfault;
-   else if (!strcmp(str, "n"))
-      result = false;
-   else if (!strcmp(str, "no"))
-      result = false;
    else if (!strcmp(str, "0"))
       result = false;
-   else if (!strcmp(str, "f"))
+   else if (!strcasecmp(str, "n"))
       result = false;
-   else if (!strcmp(str, "F"))
+   else if (!strcasecmp(str, "no"))
       result = false;
-   else if (!strcmp(str, "false"))
+   else if (!strcasecmp(str, "f"))
       result = false;
-   else if (!strcmp(str, "FALSE"))
+   else if (!strcasecmp(str, "false"))
       result = false;
-   else
+   else if (!strcmp(str, "1"))
       result = true;
+   else if (!strcasecmp(str, "y"))
+      result = true;
+   else if (!strcasecmp(str, "yes"))
+      result = true;
+   else if (!strcasecmp(str, "t"))
+      result = true;
+   else if (!strcasecmp(str, "true"))
+      result = true;
+   else
+      result = dfault;
 
    if (debug_get_option_should_print())
       debug_printf("%s: %s = %s\n", __FUNCTION__, name,
@@ -408,6 +420,91 @@ debug_dump_flags(const struct debug_named_value *names, unsigned long value)
 }
 
 
+uint64_t
+parse_debug_string(const char *debug,
+                   const struct debug_control *control)
+{
+   uint64_t flag = 0;
+
+   if (debug != NULL) {
+      for (; control->string != NULL; control++) {
+         if (!strcmp(debug, "all")) {
+            flag |= control->flag;
+
+         } else {
+            const char *s = debug;
+            unsigned n;
+
+            for (; n = strcspn(s, ", "), *s; s += MAX2(1, n)) {
+               if (strlen(control->string) == n &&
+                   !strncmp(control->string, s, n))
+                  flag |= control->flag;
+            }
+         }
+      }
+   }
+
+   return flag;
+}
+
+
+uint64_t
+parse_enable_string(const char *debug,
+                    uint64_t default_value,
+                    const struct debug_control *control)
+{
+   uint64_t flag = default_value;
+
+   if (debug != NULL) {
+      for (; control->string != NULL; control++) {
+         if (!strcmp(debug, "all")) {
+            flag |= control->flag;
+
+         } else {
+            const char *s = debug;
+            unsigned n;
+
+            for (; n = strcspn(s, ", "), *s; s += MAX2(1, n)) {
+               bool enable;
+               if (s[0] == '+') {
+                  enable = true;
+                  s++; n--;
+               } else if (s[0] == '-') {
+                  enable = false;
+                  s++; n--;
+               } else {
+                  enable = true;
+               }
+               if (strlen(control->string) == n &&
+                   !strncmp(control->string, s, n)) {
+                  if (enable)
+                     flag |= control->flag;
+                  else
+                     flag &= ~control->flag;
+               }
+            }
+         }
+      }
+   }
+
+   return flag;
+}
+
+
+bool
+comma_separated_list_contains(const char *list, const char *s)
+{
+   assert(list);
+   const size_t len = strlen(s);
+
+   for (unsigned n; n = strcspn(list, ","), *list; list += MAX2(1, n)) {
+      if (n == len && !strncmp(list, s, n))
+         return true;
+   }
+
+   return false;
+}
+
 
 #ifdef DEBUG
 int fl_indent = 0;