From 2450e6be2223b4895bfa239364996c882c0229af Mon Sep 17 00:00:00 2001
From: Miodrag Milanovic <mmicko@gmail.com>
Date: Fri, 25 Nov 2022 16:18:02 +0100
Subject: [PATCH] Add TCL interactive shell mode

---
 kernel/driver.cc | 30 +++++++++++++++++++++++++-----
 kernel/yosys.cc  | 12 +++++++++---
 2 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/kernel/driver.cc b/kernel/driver.cc
index 6d996783e..aa90802c9 100644
--- a/kernel/driver.cc
+++ b/kernel/driver.cc
@@ -202,6 +202,11 @@ extern char *yosys_argv0;
 extern char yosys_path[PATH_MAX];
 };
 #endif
+#ifdef YOSYS_ENABLE_TCL
+namespace Yosys {
+	extern int yosys_tcl_iterp_init(Tcl_Interp *interp);
+};
+#endif
 
 int main(int argc, char **argv)
 {
@@ -221,6 +226,7 @@ int main(int argc, char **argv)
 	bool call_abort = false;
 	bool timing_details = false;
 	bool run_shell = true;
+	bool run_tcl_shell = false;
 	bool mode_v = false;
 	bool mode_q = false;
 
@@ -284,6 +290,9 @@ int main(int argc, char **argv)
 		printf("\n");
 		printf("    -c tcl_scriptfile\n");
 		printf("        execute the commands in the tcl script file (see 'help tcl' for details)\n");
+		printf("\n");
+		printf("    -C\n");
+		printf("        enters TCL interatcive shell mode\n");
 #endif
 		printf("\n");
 		printf("    -p command\n");
@@ -358,7 +367,7 @@ int main(int argc, char **argv)
 	}
 
 	int opt;
-	while ((opt = getopt(argc, argv, "MXAQTVSgm:f:Hh:b:o:p:l:L:qv:tds:c:W:w:e:r:D:P:E:x:B:")) != -1)
+	while ((opt = getopt(argc, argv, "MXAQTVCSgm:f:Hh:b:o:p:l:L:qv:tds:c:W:w:e:r:D:P:E:x:B:")) != -1)
 	{
 		switch (opt)
 		{
@@ -496,6 +505,9 @@ int main(int argc, char **argv)
 		case 'B':
 			perffile = optarg;
 			break;
+		case 'C':
+			run_tcl_shell = true;
+			break;
 		default:
 			fprintf(stderr, "Run '%s -h' for help.\n", argv[0]);
 			exit(1);
@@ -570,10 +582,18 @@ int main(int argc, char **argv)
 	for (auto it = passes_commands.begin(); it != passes_commands.end(); it++)
 		run_pass(*it);
 
-	if (run_shell)
-		shell(yosys_design);
-	else
-		run_backend(output_filename, backend_command);
+	if (run_tcl_shell) {
+#ifdef YOSYS_ENABLE_TCL
+		Tcl_Main(argc, argv, yosys_tcl_iterp_init);
+#else
+		log_error("Can't exectue TCL shell: this version of yosys is not built with TCL support enabled.\n");
+#endif
+	} else {
+		if (run_shell)
+			shell(yosys_design);
+		else
+			run_backend(output_filename, backend_command);
+	}
 
 	yosys_design->check();
 	for (auto it : saved_designs)
diff --git a/kernel/yosys.cc b/kernel/yosys.cc
index a56a066fe..4a22d0a7b 100644
--- a/kernel/yosys.cc
+++ b/kernel/yosys.cc
@@ -740,13 +740,19 @@ static int tcl_yosys_cmd(ClientData, Tcl_Interp *interp, int argc, const char *a
 	return TCL_OK;
 }
 
+int yosys_tcl_iterp_init(Tcl_Interp *interp)
+{
+    if (Tcl_Init(interp)!=TCL_OK)
+		log_warning("Tcl_Init() call failed - %s\n",Tcl_ErrnoMsg(Tcl_GetErrno()));
+	Tcl_CreateCommand(interp, "yosys", tcl_yosys_cmd, NULL, NULL);
+    return TCL_OK ;
+}
+
 extern Tcl_Interp *yosys_get_tcl_interp()
 {
 	if (yosys_tcl_interp == NULL) {
 		yosys_tcl_interp = Tcl_CreateInterp();
-		if (Tcl_Init(yosys_tcl_interp)!=TCL_OK)
-			log_warning("Tcl_Init() call failed - %s\n",Tcl_ErrnoMsg(Tcl_GetErrno()));
-		Tcl_CreateCommand(yosys_tcl_interp, "yosys", tcl_yosys_cmd, NULL, NULL);
+		yosys_tcl_iterp_init(yosys_tcl_interp);
 	}
 	return yosys_tcl_interp;
 }