register.h: Add internal_flag to Pass

Update experimental pass warnings to use a shared function.  Reduces repetition, and also allows all of the warning flags to be combined (which at present is just experimental and the new internal).
Update `test_*` passes to call `internal()` in their constructors.

backends/functional/test_generic.cc

@@ -116,7 +116,9 @@ struct MemContentsTest {
 
 struct FunctionalTestGeneric : public Pass
 {
-	FunctionalTestGeneric() : Pass("test_generic", "test the generic compute graph") {}
+	FunctionalTestGeneric() : Pass("test_generic", "test the generic compute graph") {
+		internal();
+	}
 
     void help() override
 	{

kernel/register.cc

@@ -695,6 +695,23 @@ static string get_cell_name(string name) {
 	return is_code_getter(name) ? name.substr(0, name.length()-1) : name;
 }
 
+static void log_warning_flags(Pass *pass) {
+	bool has_warnings = false;
+	const string name = pass->pass_name;
+	if (pass->experimental_flag) {
+		if (!has_warnings) log("\n");
+		has_warnings = true;
+		log("WARNING: THE '%s' COMMAND IS EXPERIMENTAL.\n", name.c_str());
+	}
+	if (pass->internal_flag) {
+		if (!has_warnings) log("\n");
+		has_warnings = true;
+		log("WARNING: THE '%s' COMMAND IS INTENDED FOR INTERNAL DEVELOPER USE ONLY.\n", name.c_str());
+	}
+	if (has_warnings)
+		log("\n");
+}
+
 static struct CellHelpMessages {
 	dict<string, SimHelper> cell_help;
 	CellHelpMessages() {
@@ -1125,11 +1142,7 @@ struct HelpPass : public Pass {
 						log("=");
 					log("\n");
 					it.second->help();
-					if (it.second->experimental_flag) {
+					log_warning_flags(it.second);
-						log("\n");
-						log("WARNING: THE '%s' COMMAND IS EXPERIMENTAL.\n", it.first.c_str());
-						log("\n");
-					}
 				}
 			}
 			else if (args[1] == "-cells") {
@@ -1149,22 +1162,14 @@ struct HelpPass : public Pass {
 					std::ostringstream buf;
 					log_streams.push_back(&buf);
 					it.second->help();
-					if (it.second->experimental_flag) {
+					log_warning_flags(it.second);
-						log("\n");
-						log("WARNING: THE '%s' COMMAND IS EXPERIMENTAL.\n", it.first.c_str());
-						log("\n");
-					}
 					log_streams.pop_back();
 					write_cmd_rst(it.first, it.second->short_help, buf.str());
 				}
 			}
 			else if (pass_register.count(args[1])) {
 				pass_register.at(args[1])->help();
-				if (pass_register.at(args[1])->experimental_flag) {
+				log_warning_flags(pass_register.at(args[1]));
-					log("\n");
-					log("WARNING: THE '%s' COMMAND IS EXPERIMENTAL.\n", args[1].c_str());
-					log("\n");
-				}
 			}
 			else if (cell_help_messages.contains(args[1])) {
 				auto help_cell = cell_help_messages.get(args[1]);

kernel/register.h

@@ -68,11 +68,16 @@ struct Pass
 	int call_counter;
 	int64_t runtime_ns;
 	bool experimental_flag = false;
+	bool internal_flag = false;
 
 	void experimental() {
 		experimental_flag = true;
 	}
 
+	void internal() {
+		internal_flag = true;
+	}
+
 	struct pre_post_exec_state_t {
 		Pass *parent_pass;
 		int64_t begin_ns;

passes/pmgen/test_pmgen.cc

@@ -117,7 +117,9 @@ void opt_eqpmux(test_pmgen_pm &pm)
 }
 
 struct TestPmgenPass : public Pass {
-	TestPmgenPass() : Pass("test_pmgen", "test pass for pmgen") { }
+	TestPmgenPass() : Pass("test_pmgen", "test pass for pmgen") {
+		internal();
+	}
 	void help() override
 	{
 		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|

passes/tests/test_abcloop.cc

@@ -243,7 +243,9 @@ static void test_abcloop()
 }
 
 struct TestAbcloopPass : public Pass {
-	TestAbcloopPass() : Pass("test_abcloop", "automatically test handling of loops in abc command") { }
+	TestAbcloopPass() : Pass("test_abcloop", "automatically test handling of loops in abc command") {
+		internal();
+	}
 	void help() override
 	{
 		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|

passes/tests/test_autotb.cc

@@ -326,7 +326,9 @@ static void autotest(std::ostream &f, RTLIL::Design *design, int num_iter, int s
 }
 
 struct TestAutotbBackend : public Backend {
-	TestAutotbBackend() : Backend("=test_autotb", "generate simple test benches") { }
+	TestAutotbBackend() : Backend("=test_autotb", "generate simple test benches") {
+		internal();
+	}
 	void help() override
 	{
 		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|

passes/tests/test_cell.cc

@@ -705,7 +705,9 @@ static void run_eval_test(RTLIL::Design *design, bool verbose, bool nosat, std::
 }
 
 struct TestCellPass : public Pass {
-	TestCellPass() : Pass("test_cell", "automatically test the implementation of a cell type") { }
+	TestCellPass() : Pass("test_cell", "automatically test the implementation of a cell type") {
+		internal();
+	}
 	void help() override
 	{
 		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|