cmdref: Export internal_flag to json

Commands flagged as internal will display a warning, just like experimental commands.
Drop `passes/tests` group in favour of `internal` group, which is automatically assigned for any command without an assigned group which is flagged as internal.

docs/source/cmd/index_internal.rst

@@ -0,0 +1,5 @@
+internal
+------------------
+
+.. autocmdgroup:: internal
+   :members:

docs/source/cmd_ref.rst

@@ -19,4 +19,5 @@ Command line reference
    /cmd/index_formal
    /cmd/index_passes*
    /cmd/index_techlibs
+   /cmd/index_internal
    /cmd/index_other

docs/util/newcmdref.py

@@ -53,6 +53,7 @@ class YosysCmd:
     source_line: int
     source_func: str
     experimental_flag: bool
+    internal_flag: bool
 
     def __init__(
             self,
@@ -62,7 +63,8 @@ def __init__(
             source_file: str = "",
             source_line: int = 0,
             source_func: str = "",
-            experimental_flag: bool = False
+            experimental_flag: bool = False,
+            internal_flag: bool = False,
     ) -> None:
         self.name = name
         self.title = title
@@ -72,6 +74,7 @@ def __init__(
         self.source_line = source_line
         self.source_func = source_func
         self.experimental_flag = experimental_flag
+        self.internal_flag = internal_flag
 
 class YosysCmdGroupDocumenter(Documenter):
     objtype = 'cmdgroup'
@@ -344,6 +347,10 @@ def add_content(self, more_content: Any | None) -> None:
             self.add_line(f'.. warning:: This command is experimental', source_name, source_line)
             self.add_line('\n', source_name)
 
+        if self.object.internal_flag:
+            self.add_line(f'.. warning:: This command is intended for internal developer use only', source_name, source_line)
+            self.add_line('\n', source_name)
+
         def render(content_list: YosysCmdContentListing, indent: int=0):
             content_source = content_list.source_file or source_name
             indent_str = '   '*indent

kernel/register.cc

@@ -938,7 +938,6 @@ struct HelpPass : public Pass {
 			auto name = it.first;
 			auto pass = it.second;
 			auto title = pass->short_help;
-			auto experimental_flag = pass->experimental_flag;
 
 			auto cmd_help = PrettyHelp();
 			auto has_pretty_help = pass->formatted_help();
@@ -1078,7 +1077,9 @@ struct HelpPass : public Pass {
 			if (!cmd_help.has_group()) {
 				string source_file = pass->location.file_name();
 				bool has_source = source_file.compare("unknown") != 0;
-				if (source_file.find("backends/") == 0 || (!has_source && name.find("read_") == 0))
+				if (pass->internal_flag)
+					cmd_help.group = "internal";
+				else if (source_file.find("backends/") == 0 || (!has_source && name.find("read_") == 0))
 					cmd_help.group = "backends";
 				else if (source_file.find("frontends/") == 0 || (!has_source && name.find("write_") == 0))
 					cmd_help.group = "frontends";
@@ -1102,8 +1103,6 @@ struct HelpPass : public Pass {
 					cmd_help.group = "passes/opt";
 				else if (name.find("proc") == 0)
 					cmd_help.group = "passes/proc";
-				else if (name.find("test") == 0)
-					cmd_help.group = "passes/tests";
 			}
 
 			if (groups.count(cmd_help.group) == 0) {
@@ -1122,7 +1121,8 @@ struct HelpPass : public Pass {
 			json.entry("source_file", pass->location.file_name());
 			json.entry("source_line", pass->location.line());
 			json.entry("source_func", pass->location.function_name());
-			json.entry("experimental_flag", experimental_flag);
+			json.entry("experimental_flag", pass->experimental_flag);
+			json.entry("internal_flag", pass->internal_flag);
 			json.end_object();
 		}
 		json.end_object();