From 0f7b8b8d23b4f5ba6a4d0f37c821a8935cd0e508 Mon Sep 17 00:00:00 2001
From: Jannis Harder <me@jix.one>
Date: Fri, 2 Dec 2022 15:29:10 +0100
Subject: [PATCH] tcl: Don't exit repl on recoverable command errors

---
 kernel/driver.cc |  2 ++
 kernel/yosys.cc  | 38 ++++++++++++++++++++++++++++++++++----
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/kernel/driver.cc b/kernel/driver.cc
index aa90802c9..a89c790d9 100644
--- a/kernel/driver.cc
+++ b/kernel/driver.cc
@@ -205,6 +205,7 @@ extern char yosys_path[PATH_MAX];
 #ifdef YOSYS_ENABLE_TCL
 namespace Yosys {
 	extern int yosys_tcl_iterp_init(Tcl_Interp *interp);
+	extern void yosys_tcl_activate_repl();
 };
 #endif
 
@@ -584,6 +585,7 @@ int main(int argc, char **argv)
 
 	if (run_tcl_shell) {
 #ifdef YOSYS_ENABLE_TCL
+		yosys_tcl_activate_repl();
 		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");
diff --git a/kernel/yosys.cc b/kernel/yosys.cc
index c75500997..9ece3a2c0 100644
--- a/kernel/yosys.cc
+++ b/kernel/yosys.cc
@@ -84,6 +84,7 @@ CellTypes yosys_celltypes;
 
 #ifdef YOSYS_ENABLE_TCL
 Tcl_Interp *yosys_tcl_interp = NULL;
+bool yosys_tcl_repl_active = false;
 #endif
 
 std::set<std::string> yosys_input_files, yosys_output_files;
@@ -773,12 +774,36 @@ static int tcl_yosys_cmd(ClientData, Tcl_Interp *interp, int argc, const char *a
 
 	yosys_get_design()->scratchpad_unset("result.json");
 
-	if (args.size() == 1) {
-		Pass::call(yosys_get_design(), args[0]);
-	} else {
-		Pass::call(yosys_get_design(), args);
+	bool in_repl = yosys_tcl_repl_active;
+	bool restore_log_cmd_error_throw = log_cmd_error_throw;
+
+	log_cmd_error_throw = true;
+
+	try {
+		if (args.size() == 1) {
+			Pass::call(yosys_get_design(), args[0]);
+		} else {
+			Pass::call(yosys_get_design(), args);
+		}
+	} catch (log_cmd_error_exception) {
+		if (in_repl) {
+			auto design = yosys_get_design();
+			while (design->selection_stack.size() > 1)
+				design->selection_stack.pop_back();
+			log_reset_stack();
+		}
+		Tcl_SetResult(interp, (char *)"Yosys command produced an error", TCL_STATIC);
+
+		yosys_tcl_repl_active = in_repl;
+		log_cmd_error_throw = restore_log_cmd_error_throw;
+		return TCL_ERROR;
+	} catch (...) {
+		log_error("uncaught exception during Yosys command invoked from TCL\n");
 	}
 
+	yosys_tcl_repl_active = in_repl;
+	log_cmd_error_throw = restore_log_cmd_error_throw;
+
 	auto &scratchpad = yosys_get_design()->scratchpad;
 	auto result = scratchpad.find("result.json");
 	if (result != scratchpad.end()) {
@@ -805,6 +830,11 @@ int yosys_tcl_iterp_init(Tcl_Interp *interp)
     return TCL_OK ;
 }
 
+void yosys_tcl_activate_repl()
+{
+	yosys_tcl_repl_active = true;
+}
+
 extern Tcl_Interp *yosys_get_tcl_interp()
 {
 	if (yosys_tcl_interp == NULL) {