From e8bc25a220edbaeeb38dc4f11b1e328fdb8ddc6d Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Tue, 13 May 2025 10:37:17 +1200
Subject: [PATCH 01/11] bugpoint: Document -wires flag

---
 passes/cmds/bugpoint.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/passes/cmds/bugpoint.cc b/passes/cmds/bugpoint.cc
index da06acedf..e1f3544b4 100644
--- a/passes/cmds/bugpoint.cc
+++ b/passes/cmds/bugpoint.cc
@@ -89,6 +89,10 @@ struct BugpointPass : public Pass {
 		log("    -updates\n");
 		log("        try to remove process updates from syncs.\n");
 		log("\n");
+		log("    -wires\n");
+		log("        try to remove wires. wires with a (* bugpoint_keep *) attribute will be\n");
+		log("        skipped.\n");
+		log("\n");
 		log("    -runner \"<prefix>\"\n");
 		log("        child process wrapping command, e.g., \"timeout 30\", or valgrind.\n");
 		log("\n");

From 996539a26fbddcff5412334a5aaafc41871aa11e Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Tue, 13 May 2025 10:37:17 +1200
Subject: [PATCH 02/11] bugpoint: Add -expect-return

Allows checking return value from crashing design.  Makes it possible to only accept designs that crash with e.g. SEGFAULT.
Based on `exec -expect-return`.
---
 passes/cmds/bugpoint.cc | 62 +++++++++++++++++++++++++++++++++++------
 1 file changed, 54 insertions(+), 8 deletions(-)

diff --git a/passes/cmds/bugpoint.cc b/passes/cmds/bugpoint.cc
index e1f3544b4..24c778fdb 100644
--- a/passes/cmds/bugpoint.cc
+++ b/passes/cmds/bugpoint.cc
@@ -50,6 +50,10 @@ struct BugpointPass : public Pass {
 		log("    -grep \"<string>\"\n");
 		log("        only consider crashes that place this string in the log file.\n");
 		log("\n");
+		log("    -expect-return <int>\n");
+		log("        only consider crashes that return the specified value. e.g. SEGFAULT\n");
+		log("        returns a value of 139.\n");
+		log("\n");
 		log("    -fast\n");
 		log("        run `proc_clean; clean -purge` after each minimization step. converges\n");
 		log("        faster, but produces larger testcases, and may fail to produce any\n");
@@ -98,7 +102,7 @@ struct BugpointPass : public Pass {
 		log("\n");
 	}
 
-	bool run_yosys(RTLIL::Design *design, string runner, string yosys_cmd, string yosys_arg)
+	int run_yosys(RTLIL::Design *design, string runner, string yosys_cmd, string yosys_arg)
 	{
 		design->sort();
 
@@ -107,7 +111,16 @@ struct BugpointPass : public Pass {
 		f.close();
 
 		string yosys_cmdline = stringf("%s %s -qq -L bugpoint-case.log %s bugpoint-case.il", runner.c_str(), yosys_cmd.c_str(), yosys_arg.c_str());
-		return run_command(yosys_cmdline) == 0;
+		auto status = run_command(yosys_cmdline);
+		// we're not processing lines, which means we're getting raw system() returns
+		if(WIFEXITED(status))
+			return WEXITSTATUS(status);
+		else if(WIFSIGNALED(status))
+			return WTERMSIG(status);
+		else if(WIFSTOPPED(status))
+			return WSTOPSIG(status);
+		else
+			return 0;
 	}
 
 	bool check_logfile(string grep)
@@ -404,6 +417,8 @@ struct BugpointPass : public Pass {
 	void execute(std::vector<std::string> args, RTLIL::Design *design) override
 	{
 		string yosys_cmd = "yosys", yosys_arg, grep, runner;
+		bool flag_expect_return = false, has_check = false;
+		int expect_return_value = 0;
 		bool fast = false, clean = false;
 		bool modules = false, ports = false, cells = false, connections = false, processes = false, assigns = false, updates = false, wires = false, has_part = false;
 
@@ -430,9 +445,19 @@ struct BugpointPass : public Pass {
 				continue;
 			}
 			if (args[argidx] == "-grep" && argidx + 1 < args.size()) {
+				has_check = true;
 				grep = args[++argidx];
 				continue;
 			}
+			if (args[argidx] == "-expect-return") {
+				flag_expect_return = true;
+				++argidx;
+				if (argidx >= args.size())
+					log_cmd_error("No expected return value specified.\n");
+
+				expect_return_value = atoi(args[argidx].c_str());
+				continue;
+			}
 			if (args[argidx] == "-fast") {
 				fast = true;
 				continue;
@@ -496,6 +521,9 @@ struct BugpointPass : public Pass {
 		if (yosys_arg.empty())
 			log_cmd_error("Missing -script or -command option.\n");
 
+		if (flag_expect_return && expect_return_value == 0 && !has_check)
+			log_cmd_error("Nothing to match on for -expect-return 0; change value or use -grep.\n");
+
 		if (!has_part)
 		{
 			modules = true;
@@ -512,7 +540,10 @@ struct BugpointPass : public Pass {
 			log_cmd_error("This command only operates on fully selected designs!\n");
 
 		RTLIL::Design *crashing_design = clean_design(design, clean);
-		if (run_yosys(crashing_design, runner, yosys_cmd, yosys_arg))
+		int retval = run_yosys(crashing_design, runner, yosys_cmd, yosys_arg);
+		if (flag_expect_return && retval != expect_return_value)
+			log_cmd_error("The provided script file or command and Yosys binary returned value %d instead of expected %d on this design!\n", retval, expect_return_value);
+		if (!flag_expect_return && retval == 0)
 			log_cmd_error("The provided script file or command and Yosys binary do not crash on this design!\n");
 		if (!check_logfile(grep))
 			log_cmd_error("The provided grep string is not found in the log file!\n");
@@ -525,21 +556,37 @@ struct BugpointPass : public Pass {
 			{
 				simplified = clean_design(simplified, fast, /*do_delete=*/true);
 
-				bool crashes;
 				if (clean)
 				{
 					RTLIL::Design *testcase = clean_design(simplified);
-					crashes = !run_yosys(testcase, runner, yosys_cmd, yosys_arg);
+					retval = run_yosys(testcase, runner, yosys_cmd, yosys_arg);
 					delete testcase;
 				}
 				else
 				{
-					crashes = !run_yosys(simplified, runner, yosys_cmd, yosys_arg);
+					retval = run_yosys(simplified, runner, yosys_cmd, yosys_arg);
 				}
 
-				if (crashes && check_logfile(grep))
+				bool crashes = false;
+				if (flag_expect_return && retval == expect_return_value && check_logfile(grep))
+				{
+					log("Testcase matches expected crash.\n");
+					crashes = true;
+				}
+				else if (!flag_expect_return && retval == 0)
+					log("Testcase does not crash.\n");
+				else if (!flag_expect_return && check_logfile(grep))
 				{
 					log("Testcase crashes.\n");
+					crashes = true;
+				}
+				else
+					// flag_expect_return && !(retval == expect_return_value && check_logfile(grep))
+					// !flag_expect_return && !(retval == 0 && check_logfile(grep))
+					log("Testcase does not match expected crash.\n");
+
+				if (crashes)
+				{
 					if (crashing_design != design)
 						delete crashing_design;
 					crashing_design = simplified;
@@ -547,7 +594,6 @@ struct BugpointPass : public Pass {
 				}
 				else
 				{
-					log("Testcase does not crash.\n");
 					delete simplified;
 					seed++;
 				}

From 50da04a75e5d7749ebdff384adcfb90a1a700292 Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Tue, 13 May 2025 15:01:45 +1200
Subject: [PATCH 03/11] bugpoint.cc: WIN32 exit signals

---
 passes/cmds/bugpoint.cc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/passes/cmds/bugpoint.cc b/passes/cmds/bugpoint.cc
index 24c778fdb..06aae1885 100644
--- a/passes/cmds/bugpoint.cc
+++ b/passes/cmds/bugpoint.cc
@@ -20,6 +20,15 @@
 #include "kernel/yosys.h"
 #include "backends/rtlil/rtlil_backend.h"
 
+#if defined(_WIN32)
+#  define WIFEXITED(x) 1
+#  define WIFSIGNALED(x) 0
+#  define WIFSTOPPED(x) 0
+#  define WEXITSTATUS(x) ((x) & 0xff)
+#  define WTERMSIG(x) SIGTERM
+#  define WSTOPSIG(x) 0
+#endif
+
 USING_YOSYS_NAMESPACE
 using namespace RTLIL_BACKEND;
 PRIVATE_NAMESPACE_BEGIN

From 107b768cddba1a2fdb8bfec1b4ffeeeaf6455be5 Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Tue, 13 May 2025 15:14:33 +1200
Subject: [PATCH 04/11] Add raise_error pass

Raise errors from attributes for testing.
I want it for bugpoint tests but it could be useful elsewhere.
---
 kernel/constids.inc         |  1 +
 passes/tests/Makefile.inc   |  1 +
 passes/tests/raise_error.cc | 61 +++++++++++++++++++++++++++++++++++++
 tests/bugpoint/.gitignore   |  2 ++
 tests/bugpoint/err.ys       | 27 ++++++++++++++++
 5 files changed, 92 insertions(+)
 create mode 100644 passes/tests/raise_error.cc
 create mode 100644 tests/bugpoint/.gitignore
 create mode 100644 tests/bugpoint/err.ys

diff --git a/kernel/constids.inc b/kernel/constids.inc
index 4fdbb3dc8..df7b75269 100644
--- a/kernel/constids.inc
+++ b/kernel/constids.inc
@@ -284,3 +284,4 @@ X(A_WIDTHS)
 X(B_WIDTHS)
 X(C_WIDTHS)
 X(C_SIGNED)
+X(raise_error)
diff --git a/passes/tests/Makefile.inc b/passes/tests/Makefile.inc
index 531943d78..25e11967c 100644
--- a/passes/tests/Makefile.inc
+++ b/passes/tests/Makefile.inc
@@ -2,4 +2,5 @@
 OBJS += passes/tests/test_autotb.o
 OBJS += passes/tests/test_cell.o
 OBJS += passes/tests/test_abcloop.o
+OBJS += passes/tests/raise_error.o
 
diff --git a/passes/tests/raise_error.cc b/passes/tests/raise_error.cc
new file mode 100644
index 000000000..edc42de65
--- /dev/null
+++ b/passes/tests/raise_error.cc
@@ -0,0 +1,61 @@
+#include "kernel/yosys.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct RaiseErrorPass : public Pass {
+	RaiseErrorPass() : Pass("raise_error", "raise errors from attributes") { }
+	void help() override
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    raise_error [selection]\n");
+		log("\n");
+		log("Test error handling by raising arbitrary errors. This pass iterates over the\n");
+		log("design (or selection of it) checking for objects with the 'raise_error'\n");
+		log("attribute set.\n");
+		log("\n");
+	}
+	void execute(vector<string> args, RTLIL::Design *design) override
+	{
+		log_header(design, "Executing RAISE_ERROR pass.\n");
+
+		extra_args(args, 1, design, true);
+
+		RTLIL::NamedObject *err_obj = nullptr;
+		
+		for (auto mod : design->all_selected_modules()) {
+			if (mod->has_attribute(ID::raise_error)) {
+				err_obj = mod->clone();
+				break;
+			}
+			for (auto memb : mod->selected_members()) {
+				if (memb->has_attribute(ID::raise_error)) {
+					err_obj = memb;
+					break;
+				}
+			}
+			if (err_obj != nullptr) break;
+		}
+
+		if (err_obj != nullptr) {
+			log("Raising error from '%s'.\n", log_id(err_obj));
+			auto err_no = err_obj->attributes[ID::raise_error].as_int();
+			if (err_no < 256) {
+				log_flush();
+			#if defined(_MSC_VER)
+				_exit(err_no);
+			#else
+				_Exit(err_no);
+			#endif
+			} else {
+				auto err_msg = err_obj->get_string_attribute(ID::raise_error);
+				log_error("%s\n", err_msg.c_str());
+			}
+		} else {
+			log("'raise_error' attribute not found\n");
+		}
+	}
+} RaiseErrorPass;
+
+PRIVATE_NAMESPACE_END
diff --git a/tests/bugpoint/.gitignore b/tests/bugpoint/.gitignore
new file mode 100644
index 000000000..072ed1097
--- /dev/null
+++ b/tests/bugpoint/.gitignore
@@ -0,0 +1,2 @@
+*.il
+*.log
\ No newline at end of file
diff --git a/tests/bugpoint/err.ys b/tests/bugpoint/err.ys
new file mode 100644
index 000000000..d6a152144
--- /dev/null
+++ b/tests/bugpoint/err.ys
@@ -0,0 +1,27 @@
+read_verilog -noblackbox << EOF
+(* raise_error=7 *)
+module top();
+endmodule
+
+(* raise_error="help me" *)
+module other();
+endmodule
+
+module zzy();
+endmodule
+EOF
+select -assert-mod-count 3 =*
+design -stash read
+
+# raise_error with int exits with status
+design -load read
+bugpoint -yosys ../../yosys -command raise_error -expect-return 7
+select -assert-mod-count 1 =*
+select -assert-mod-count 1 top
+
+# raise_error with string prints message
+design -load read
+rename top abc
+bugpoint -yosys ../../yosys -command raise_error -grep "help me"
+select -assert-mod-count 1 =*
+select -assert-mod-count 1 other

From b5c91c53a66b2e5aaa50c3ae14e33ca8ce5da4e0 Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Tue, 13 May 2025 17:05:17 +1200
Subject: [PATCH 05/11] raise_error.cc: Option for direct to stderr

Add more to help text to describe usage.
Add test for no value (should `exit(1)`).
---
 passes/tests/raise_error.cc | 40 ++++++++++++++++++++++++++++---------
 tests/bugpoint/err.ys       | 27 ++++++++++++++++++++++++-
 2 files changed, 57 insertions(+), 10 deletions(-)

diff --git a/passes/tests/raise_error.cc b/passes/tests/raise_error.cc
index edc42de65..f9055e6d2 100644
--- a/passes/tests/raise_error.cc
+++ b/passes/tests/raise_error.cc
@@ -9,18 +9,35 @@ struct RaiseErrorPass : public Pass {
 	{
 		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
 		log("\n");
-		log("    raise_error [selection]\n");
+		log("    raise_error [options] [selection]\n");
 		log("\n");
 		log("Test error handling by raising arbitrary errors. This pass iterates over the\n");
 		log("design (or selection of it) checking for objects with the 'raise_error'\n");
-		log("attribute set.\n");
+		log("attribute set. Assigning 'raise_error' to a string more than one character long\n");
+		log("will log that string as an error message before exiting. Assigning 'raise_error'\n");
+		log("to an integer (less than 256) will exit with that value as the exit code.\n");
+		log("\n");
+		log("    -stderr\n");
+		log("        Log error messages directly to stderr instead of using 'log_error'.\n");
 		log("\n");
 	}
 	void execute(vector<string> args, RTLIL::Design *design) override
 	{
 		log_header(design, "Executing RAISE_ERROR pass.\n");
 
-		extra_args(args, 1, design, true);
+		bool use_stderr = false;
+
+		int argidx;
+		for (argidx = 1; argidx < GetSize(args); argidx++)
+		{
+			if (args[argidx] == "-stderr") {
+				use_stderr = true;
+				continue;
+			}
+			break;
+		}
+
+		extra_args(args, argidx, design, true);
 
 		RTLIL::NamedObject *err_obj = nullptr;
 		
@@ -43,15 +60,20 @@ struct RaiseErrorPass : public Pass {
 			auto err_no = err_obj->attributes[ID::raise_error].as_int();
 			if (err_no < 256) {
 				log_flush();
-			#if defined(_MSC_VER)
-				_exit(err_no);
-			#else
-				_Exit(err_no);
-			#endif
 			} else {
 				auto err_msg = err_obj->get_string_attribute(ID::raise_error);
-				log_error("%s\n", err_msg.c_str());
+				if (use_stderr) {
+					std::cerr << err_msg << std::endl;
+					err_no = 1;
+				} else {
+					log_error("%s\n", err_msg.c_str());
+				}
 			}
+		#if defined(_MSC_VER)
+			_exit(err_no);
+		#else
+			_Exit(err_no);
+		#endif
 		} else {
 			log("'raise_error' attribute not found\n");
 		}
diff --git a/tests/bugpoint/err.ys b/tests/bugpoint/err.ys
index d6a152144..7b2fbcc81 100644
--- a/tests/bugpoint/err.ys
+++ b/tests/bugpoint/err.ys
@@ -7,7 +7,8 @@ endmodule
 module other();
 endmodule
 
-module zzy();
+(* raise_error *)
+module def();
 endmodule
 EOF
 select -assert-mod-count 3 =*
@@ -25,3 +26,27 @@ rename top abc
 bugpoint -yosys ../../yosys -command raise_error -grep "help me"
 select -assert-mod-count 1 =*
 select -assert-mod-count 1 other
+
+# raise_error with no value exits with 1
+design -load read
+rename def zzy
+bugpoint -yosys ../../yosys -command raise_error -expect-return 1
+select -assert-mod-count 1 =*
+select -assert-mod-count 1 zzy
+
+# raise_error -stderr exits with 1
+design -load read
+rename top abc
+delete def
+bugpoint -yosys ../../yosys -command "raise_error -stderr" -expect-return 1
+select -assert-mod-count 1 =*
+select -assert-mod-count 1 other
+
+#TODO
+# raise_error -stderr prints to stderr
+design -load read
+rename top abc
+delete def
+# bugpoint -yosys ../../yosys -command "raise_error -stderr" -grep "help me"
+# select -assert-mod-count 1 =*
+# select -assert-mod-count 1 other

From 2991be2a2d8fcc4a8781bf7b8ab54d2e9ba39697 Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Tue, 13 May 2025 17:51:40 +1200
Subject: [PATCH 06/11] bugpoint: Add -greperr option

`-greperr <string>` redirects stderr to 'bugpoint-case.err', and then searches that file for `<string>`.
Move `-runner` option up with the other options to reduce ambiguity (i.e. so it doesn't look like it's another design parts constraint).
Also some shuffling of `err.ys`.
---
 passes/cmds/bugpoint.cc   | 53 ++++++++++++++++++++++++++++-----------
 tests/bugpoint/.gitignore |  3 ++-
 tests/bugpoint/err.ys     | 19 ++++----------
 3 files changed, 45 insertions(+), 30 deletions(-)

diff --git a/passes/cmds/bugpoint.cc b/passes/cmds/bugpoint.cc
index 06aae1885..11f6de35b 100644
--- a/passes/cmds/bugpoint.cc
+++ b/passes/cmds/bugpoint.cc
@@ -73,6 +73,13 @@ struct BugpointPass : public Pass {
 		log("        finishing. produces smaller and more useful testcases, but may fail to\n");
 		log("        produce any testcase at all if the crash is related to dangling wires.\n");
 		log("\n");
+		log("    -runner \"<prefix>\"\n");
+		log("        child process wrapping command, e.g., \"timeout 30\", or valgrind.\n");
+		log("\n");
+		log("    -greperr \"<string>\"\n");
+		log("        only consider crashes that print this string on stderr. useful for\n");
+		log("        errors outside of yosys.\n");
+		log("\n");
 		log("It is possible to constrain which parts of the design will be considered for\n");
 		log("removal. Unless one or more of the following options are specified, all parts\n");
 		log("will be considered.\n");
@@ -106,12 +113,9 @@ struct BugpointPass : public Pass {
 		log("        try to remove wires. wires with a (* bugpoint_keep *) attribute will be\n");
 		log("        skipped.\n");
 		log("\n");
-		log("    -runner \"<prefix>\"\n");
-		log("        child process wrapping command, e.g., \"timeout 30\", or valgrind.\n");
-		log("\n");
 	}
 
-	int run_yosys(RTLIL::Design *design, string runner, string yosys_cmd, string yosys_arg)
+	int run_yosys(RTLIL::Design *design, string runner, string yosys_cmd, string yosys_arg, bool catch_err)
 	{
 		design->sort();
 
@@ -120,6 +124,7 @@ struct BugpointPass : public Pass {
 		f.close();
 
 		string yosys_cmdline = stringf("%s %s -qq -L bugpoint-case.log %s bugpoint-case.il", runner.c_str(), yosys_cmd.c_str(), yosys_arg.c_str());
+		if (catch_err) yosys_cmdline += " 2>bugpoint-case.err";
 		auto status = run_command(yosys_cmdline);
 		// we're not processing lines, which means we're getting raw system() returns
 		if(WIFEXITED(status))
@@ -132,7 +137,7 @@ struct BugpointPass : public Pass {
 			return 0;
 	}
 
-	bool check_logfile(string grep)
+	bool check_logfile(string grep, bool err=false)
 	{
 		if (grep.empty())
 			return true;
@@ -140,7 +145,12 @@ struct BugpointPass : public Pass {
 		if (grep.size() > 2 && grep.front() == '"' && grep.back() == '"')
 			grep = grep.substr(1, grep.size() - 2);
 
-		std::ifstream f("bugpoint-case.log");
+		std::ifstream f;
+		if (err)
+			f = std::ifstream("bugpoint-case.err");
+		else
+			f = std::ifstream("bugpoint-case.log");
+
 		while (!f.eof())
 		{
 			string line;
@@ -151,6 +161,11 @@ struct BugpointPass : public Pass {
 		return false;
 	}
 
+	bool check_logfiles(string grep, string greperr)
+	{
+		return check_logfile(grep) && check_logfile(greperr, true);
+	}
+
 	RTLIL::Design *clean_design(RTLIL::Design *design, bool do_clean = true, bool do_delete = false)
 	{
 		if (!do_clean)
@@ -425,8 +440,8 @@ struct BugpointPass : public Pass {
 
 	void execute(std::vector<std::string> args, RTLIL::Design *design) override
 	{
-		string yosys_cmd = "yosys", yosys_arg, grep, runner;
-		bool flag_expect_return = false, has_check = false;
+		string yosys_cmd = "yosys", yosys_arg, grep, greperr, runner;
+		bool flag_expect_return = false, has_check = false, check_err = false;
 		int expect_return_value = 0;
 		bool fast = false, clean = false;
 		bool modules = false, ports = false, cells = false, connections = false, processes = false, assigns = false, updates = false, wires = false, has_part = false;
@@ -458,6 +473,12 @@ struct BugpointPass : public Pass {
 				grep = args[++argidx];
 				continue;
 			}
+			if (args[argidx] == "-greperr" && argidx + 1 < args.size()) {
+				has_check = true;
+				check_err = true;
+				greperr = args[++argidx];
+				continue;
+			}
 			if (args[argidx] == "-expect-return") {
 				flag_expect_return = true;
 				++argidx;
@@ -549,13 +570,15 @@ struct BugpointPass : public Pass {
 			log_cmd_error("This command only operates on fully selected designs!\n");
 
 		RTLIL::Design *crashing_design = clean_design(design, clean);
-		int retval = run_yosys(crashing_design, runner, yosys_cmd, yosys_arg);
+		int retval = run_yosys(crashing_design, runner, yosys_cmd, yosys_arg, check_err);
 		if (flag_expect_return && retval != expect_return_value)
 			log_cmd_error("The provided script file or command and Yosys binary returned value %d instead of expected %d on this design!\n", retval, expect_return_value);
 		if (!flag_expect_return && retval == 0)
 			log_cmd_error("The provided script file or command and Yosys binary do not crash on this design!\n");
 		if (!check_logfile(grep))
 			log_cmd_error("The provided grep string is not found in the log file!\n");
+		if (!check_logfile(greperr, true))
+			log_cmd_error("The provided grep string is not found in stderr log!\n");
 
 		int seed = 0;
 		bool found_something = false, stage2 = false;
@@ -568,30 +591,30 @@ struct BugpointPass : public Pass {
 				if (clean)
 				{
 					RTLIL::Design *testcase = clean_design(simplified);
-					retval = run_yosys(testcase, runner, yosys_cmd, yosys_arg);
+					retval = run_yosys(testcase, runner, yosys_cmd, yosys_arg, check_err);
 					delete testcase;
 				}
 				else
 				{
-					retval = run_yosys(simplified, runner, yosys_cmd, yosys_arg);
+					retval = run_yosys(simplified, runner, yosys_cmd, yosys_arg, check_err);
 				}
 
 				bool crashes = false;
-				if (flag_expect_return && retval == expect_return_value && check_logfile(grep))
+				if (flag_expect_return && retval == expect_return_value && check_logfiles(grep, greperr))
 				{
 					log("Testcase matches expected crash.\n");
 					crashes = true;
 				}
 				else if (!flag_expect_return && retval == 0)
 					log("Testcase does not crash.\n");
-				else if (!flag_expect_return && check_logfile(grep))
+				else if (!flag_expect_return && check_logfiles(grep, greperr))
 				{
 					log("Testcase crashes.\n");
 					crashes = true;
 				}
 				else
-					// flag_expect_return && !(retval == expect_return_value && check_logfile(grep))
-					// !flag_expect_return && !(retval == 0 && check_logfile(grep))
+					// flag_expect_return && !(retval == expect_return_value && check_logfiles(grep, greperr))
+					// !flag_expect_return && !(retval == 0 && check_logfiles(grep, greperr))
 					log("Testcase does not match expected crash.\n");
 
 				if (crashes)
diff --git a/tests/bugpoint/.gitignore b/tests/bugpoint/.gitignore
index 072ed1097..818575593 100644
--- a/tests/bugpoint/.gitignore
+++ b/tests/bugpoint/.gitignore
@@ -1,2 +1,3 @@
 *.il
-*.log
\ No newline at end of file
+*.log
+*.err
diff --git a/tests/bugpoint/err.ys b/tests/bugpoint/err.ys
index 7b2fbcc81..c74e34b19 100644
--- a/tests/bugpoint/err.ys
+++ b/tests/bugpoint/err.ys
@@ -20,33 +20,24 @@ bugpoint -yosys ../../yosys -command raise_error -expect-return 7
 select -assert-mod-count 1 =*
 select -assert-mod-count 1 top
 
-# raise_error with string prints message
+# raise_error with string prints message and exits with 1
 design -load read
 rename top abc
-bugpoint -yosys ../../yosys -command raise_error -grep "help me"
+bugpoint -yosys ../../yosys -command raise_error -grep "help me" -expect-return 1
 select -assert-mod-count 1 =*
 select -assert-mod-count 1 other
 
 # raise_error with no value exits with 1
 design -load read
 rename def zzy
+delete other
 bugpoint -yosys ../../yosys -command raise_error -expect-return 1
 select -assert-mod-count 1 =*
 select -assert-mod-count 1 zzy
 
-# raise_error -stderr exits with 1
+# raise_error -stderr prints to stderr and exits with 1
 design -load read
 rename top abc
-delete def
-bugpoint -yosys ../../yosys -command "raise_error -stderr" -expect-return 1
+bugpoint -yosys ../../yosys -command "raise_error -stderr" -greperr "help me" -expect-return 1
 select -assert-mod-count 1 =*
 select -assert-mod-count 1 other
-
-#TODO
-# raise_error -stderr prints to stderr
-design -load read
-rename top abc
-delete def
-# bugpoint -yosys ../../yosys -command "raise_error -stderr" -grep "help me"
-# select -assert-mod-count 1 =*
-# select -assert-mod-count 1 other

From aa03da56cb8b0b98864269c4f88de6f135831b74 Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Wed, 14 May 2025 10:06:06 +1200
Subject: [PATCH 07/11] bugpoint.cc: Include csignal for windows

---
 passes/cmds/bugpoint.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/passes/cmds/bugpoint.cc b/passes/cmds/bugpoint.cc
index 11f6de35b..101d82bd6 100644
--- a/passes/cmds/bugpoint.cc
+++ b/passes/cmds/bugpoint.cc
@@ -21,6 +21,7 @@
 #include "backends/rtlil/rtlil_backend.h"
 
 #if defined(_WIN32)
+#  include <csignal>
 #  define WIFEXITED(x) 1
 #  define WIFSIGNALED(x) 0
 #  define WIFSTOPPED(x) 0

From 65a5227c144887b74e3ab481e6416fe6089bab8e Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Wed, 14 May 2025 10:19:06 +1200
Subject: [PATCH 08/11] bugpoint.cc: Rename to -err_grep

---
 passes/cmds/bugpoint.cc | 22 +++++++++++-----------
 tests/bugpoint/err.ys   |  2 +-
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/passes/cmds/bugpoint.cc b/passes/cmds/bugpoint.cc
index 101d82bd6..f740c2bcd 100644
--- a/passes/cmds/bugpoint.cc
+++ b/passes/cmds/bugpoint.cc
@@ -77,7 +77,7 @@ struct BugpointPass : public Pass {
 		log("    -runner \"<prefix>\"\n");
 		log("        child process wrapping command, e.g., \"timeout 30\", or valgrind.\n");
 		log("\n");
-		log("    -greperr \"<string>\"\n");
+		log("    -err_grep \"<string>\"\n");
 		log("        only consider crashes that print this string on stderr. useful for\n");
 		log("        errors outside of yosys.\n");
 		log("\n");
@@ -162,9 +162,9 @@ struct BugpointPass : public Pass {
 		return false;
 	}
 
-	bool check_logfiles(string grep, string greperr)
+	bool check_logfiles(string grep, string err_grep)
 	{
-		return check_logfile(grep) && check_logfile(greperr, true);
+		return check_logfile(grep) && check_logfile(err_grep, true);
 	}
 
 	RTLIL::Design *clean_design(RTLIL::Design *design, bool do_clean = true, bool do_delete = false)
@@ -441,7 +441,7 @@ struct BugpointPass : public Pass {
 
 	void execute(std::vector<std::string> args, RTLIL::Design *design) override
 	{
-		string yosys_cmd = "yosys", yosys_arg, grep, greperr, runner;
+		string yosys_cmd = "yosys", yosys_arg, grep, err_grep, runner;
 		bool flag_expect_return = false, has_check = false, check_err = false;
 		int expect_return_value = 0;
 		bool fast = false, clean = false;
@@ -474,10 +474,10 @@ struct BugpointPass : public Pass {
 				grep = args[++argidx];
 				continue;
 			}
-			if (args[argidx] == "-greperr" && argidx + 1 < args.size()) {
+			if (args[argidx] == "-err_grep" && argidx + 1 < args.size()) {
 				has_check = true;
 				check_err = true;
-				greperr = args[++argidx];
+				err_grep = args[++argidx];
 				continue;
 			}
 			if (args[argidx] == "-expect-return") {
@@ -578,7 +578,7 @@ struct BugpointPass : public Pass {
 			log_cmd_error("The provided script file or command and Yosys binary do not crash on this design!\n");
 		if (!check_logfile(grep))
 			log_cmd_error("The provided grep string is not found in the log file!\n");
-		if (!check_logfile(greperr, true))
+		if (!check_logfile(err_grep, true))
 			log_cmd_error("The provided grep string is not found in stderr log!\n");
 
 		int seed = 0;
@@ -601,21 +601,21 @@ struct BugpointPass : public Pass {
 				}
 
 				bool crashes = false;
-				if (flag_expect_return && retval == expect_return_value && check_logfiles(grep, greperr))
+				if (flag_expect_return && retval == expect_return_value && check_logfiles(grep, err_grep))
 				{
 					log("Testcase matches expected crash.\n");
 					crashes = true;
 				}
 				else if (!flag_expect_return && retval == 0)
 					log("Testcase does not crash.\n");
-				else if (!flag_expect_return && check_logfiles(grep, greperr))
+				else if (!flag_expect_return && check_logfiles(grep, err_grep))
 				{
 					log("Testcase crashes.\n");
 					crashes = true;
 				}
 				else
-					// flag_expect_return && !(retval == expect_return_value && check_logfiles(grep, greperr))
-					// !flag_expect_return && !(retval == 0 && check_logfiles(grep, greperr))
+					// flag_expect_return && !(retval == expect_return_value && check_logfiles(grep, err_grep))
+					// !flag_expect_return && !(retval == 0 && check_logfiles(grep, err_grep))
 					log("Testcase does not match expected crash.\n");
 
 				if (crashes)
diff --git a/tests/bugpoint/err.ys b/tests/bugpoint/err.ys
index c74e34b19..08bf0a9c7 100644
--- a/tests/bugpoint/err.ys
+++ b/tests/bugpoint/err.ys
@@ -38,6 +38,6 @@ select -assert-mod-count 1 zzy
 # raise_error -stderr prints to stderr and exits with 1
 design -load read
 rename top abc
-bugpoint -yosys ../../yosys -command "raise_error -stderr" -greperr "help me" -expect-return 1
+bugpoint -yosys ../../yosys -command "raise_error -stderr" -err_grep "help me" -expect-return 1
 select -assert-mod-count 1 =*
 select -assert-mod-count 1 other

From ded51e7622a26e3b7e9880a049a77beacbf3badf Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Fri, 16 May 2025 14:12:38 +1200
Subject: [PATCH 09/11] tests: Add bugpoint to MK_TEST_DIRS

Also change `-err_grep` to `-err-grep` for consistency with `-expect-return`.
---
 Makefile                   | 1 +
 passes/cmds/bugpoint.cc    | 4 ++--
 tests/bugpoint/err.ys      | 2 +-
 tests/bugpoint/run-test.sh | 4 ++++
 4 files changed, 8 insertions(+), 3 deletions(-)
 create mode 100755 tests/bugpoint/run-test.sh

diff --git a/Makefile b/Makefile
index fb0ad0e37..1f8a47470 100644
--- a/Makefile
+++ b/Makefile
@@ -866,6 +866,7 @@ MK_TEST_DIRS += tests/arch/nexus
 MK_TEST_DIRS += tests/arch/quicklogic/pp3
 MK_TEST_DIRS += tests/arch/quicklogic/qlf_k6n10f
 MK_TEST_DIRS += tests/arch/xilinx
+MK_TEST_DIRS += tests/bugpoint
 MK_TEST_DIRS += tests/opt
 MK_TEST_DIRS += tests/sat
 MK_TEST_DIRS += tests/sim
diff --git a/passes/cmds/bugpoint.cc b/passes/cmds/bugpoint.cc
index f740c2bcd..683430372 100644
--- a/passes/cmds/bugpoint.cc
+++ b/passes/cmds/bugpoint.cc
@@ -77,7 +77,7 @@ struct BugpointPass : public Pass {
 		log("    -runner \"<prefix>\"\n");
 		log("        child process wrapping command, e.g., \"timeout 30\", or valgrind.\n");
 		log("\n");
-		log("    -err_grep \"<string>\"\n");
+		log("    -err-grep \"<string>\"\n");
 		log("        only consider crashes that print this string on stderr. useful for\n");
 		log("        errors outside of yosys.\n");
 		log("\n");
@@ -474,7 +474,7 @@ struct BugpointPass : public Pass {
 				grep = args[++argidx];
 				continue;
 			}
-			if (args[argidx] == "-err_grep" && argidx + 1 < args.size()) {
+			if (args[argidx] == "-err-grep" && argidx + 1 < args.size()) {
 				has_check = true;
 				check_err = true;
 				err_grep = args[++argidx];
diff --git a/tests/bugpoint/err.ys b/tests/bugpoint/err.ys
index 08bf0a9c7..42e84241c 100644
--- a/tests/bugpoint/err.ys
+++ b/tests/bugpoint/err.ys
@@ -38,6 +38,6 @@ select -assert-mod-count 1 zzy
 # raise_error -stderr prints to stderr and exits with 1
 design -load read
 rename top abc
-bugpoint -yosys ../../yosys -command "raise_error -stderr" -err_grep "help me" -expect-return 1
+bugpoint -yosys ../../yosys -command "raise_error -stderr" -err-grep "help me" -expect-return 1
 select -assert-mod-count 1 =*
 select -assert-mod-count 1 other
diff --git a/tests/bugpoint/run-test.sh b/tests/bugpoint/run-test.sh
new file mode 100755
index 000000000..006c731e3
--- /dev/null
+++ b/tests/bugpoint/run-test.sh
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+set -eu
+source ../gen-tests-makefile.sh
+generate_mk --yosys-scripts

From 2d8fa9fbefdc2094988edcee887522fdc4656af8 Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Fri, 16 May 2025 16:51:48 +1200
Subject: [PATCH 10/11] bugpoint: Add -suffix option

Allows for adding a suffix to the `bugpoint-case` file name so that multiple `bugpoint`s can run in the same directory, e.g. during a `make test -j4`.
---
 passes/cmds/bugpoint.cc | 61 ++++++++++++++++++++++++++---------------
 1 file changed, 39 insertions(+), 22 deletions(-)

diff --git a/passes/cmds/bugpoint.cc b/passes/cmds/bugpoint.cc
index 683430372..08dc76dda 100644
--- a/passes/cmds/bugpoint.cc
+++ b/passes/cmds/bugpoint.cc
@@ -81,6 +81,10 @@ struct BugpointPass : public Pass {
 		log("        only consider crashes that print this string on stderr. useful for\n");
 		log("        errors outside of yosys.\n");
 		log("\n");
+		log("    -suffix \"<string>\"\n");
+		log("        add suffix to generated file names. useful when running more than one\n");
+		log("        instance of bugpoint in the same directory. limited to 8 characters.\n");
+		log("\n");
 		log("It is possible to constrain which parts of the design will be considered for\n");
 		log("removal. Unless one or more of the following options are specified, all parts\n");
 		log("will be considered.\n");
@@ -116,16 +120,20 @@ struct BugpointPass : public Pass {
 		log("\n");
 	}
 
-	int run_yosys(RTLIL::Design *design, string runner, string yosys_cmd, string yosys_arg, bool catch_err)
+	int run_yosys(RTLIL::Design *design, string runner, string yosys_cmd, string yosys_arg, string suffix, bool catch_err)
 	{
 		design->sort();
 
-		std::ofstream f("bugpoint-case.il");
+		string bugpoint_file = "bugpoint-case";
+		if (suffix.size())
+			bugpoint_file += stringf(".%.8s", suffix.c_str());
+
+		std::ofstream f(bugpoint_file + ".il");
 		RTLIL_BACKEND::dump_design(f, design, /*only_selected=*/false, /*flag_m=*/true, /*flag_n=*/false);
 		f.close();
 
-		string yosys_cmdline = stringf("%s %s -qq -L bugpoint-case.log %s bugpoint-case.il", runner.c_str(), yosys_cmd.c_str(), yosys_arg.c_str());
-		if (catch_err) yosys_cmdline += " 2>bugpoint-case.err";
+		string yosys_cmdline = stringf("%s %s -qq -L %s.log %s %s.il", runner.c_str(), yosys_cmd.c_str(), bugpoint_file.c_str(), yosys_arg.c_str(), bugpoint_file.c_str());
+		if (catch_err) yosys_cmdline += stringf(" 2>%s.err", bugpoint_file.c_str());
 		auto status = run_command(yosys_cmdline);
 		// we're not processing lines, which means we're getting raw system() returns
 		if(WIFEXITED(status))
@@ -138,7 +146,7 @@ struct BugpointPass : public Pass {
 			return 0;
 	}
 
-	bool check_logfile(string grep, bool err=false)
+	bool check_logfile(string grep, string suffix, bool err=false)
 	{
 		if (grep.empty())
 			return true;
@@ -146,11 +154,12 @@ struct BugpointPass : public Pass {
 		if (grep.size() > 2 && grep.front() == '"' && grep.back() == '"')
 			grep = grep.substr(1, grep.size() - 2);
 
-		std::ifstream f;
-		if (err)
-			f = std::ifstream("bugpoint-case.err");
-		else
-			f = std::ifstream("bugpoint-case.log");
+		string bugpoint_file = "bugpoint-case";
+		if (suffix.size())
+			bugpoint_file += stringf(".%.8s", suffix.c_str());
+		bugpoint_file += err ? ".err" : ".log";
+
+		std::ifstream f(bugpoint_file);
 
 		while (!f.eof())
 		{
@@ -162,9 +171,9 @@ struct BugpointPass : public Pass {
 		return false;
 	}
 
-	bool check_logfiles(string grep, string err_grep)
+	bool check_logfiles(string grep, string err_grep, string suffix)
 	{
-		return check_logfile(grep) && check_logfile(err_grep, true);
+		return check_logfile(grep, suffix) && check_logfile(err_grep, suffix, true);
 	}
 
 	RTLIL::Design *clean_design(RTLIL::Design *design, bool do_clean = true, bool do_delete = false)
@@ -441,7 +450,7 @@ struct BugpointPass : public Pass {
 
 	void execute(std::vector<std::string> args, RTLIL::Design *design) override
 	{
-		string yosys_cmd = "yosys", yosys_arg, grep, err_grep, runner;
+		string yosys_cmd = "yosys", yosys_arg, grep, err_grep, runner, suffix;
 		bool flag_expect_return = false, has_check = false, check_err = false;
 		int expect_return_value = 0;
 		bool fast = false, clean = false;
@@ -545,6 +554,14 @@ struct BugpointPass : public Pass {
 				}
 				continue;
 			}
+			if (args[argidx] == "-suffix" && argidx + 1 < args.size()) {
+				suffix = args[++argidx];
+				if (suffix.size() && suffix.at(0) == '"') {
+					log_assert(suffix.back() == '"');
+					suffix = suffix.substr(1, suffix.size() - 2);
+				}
+				continue;
+			}
 			break;
 		}
 		extra_args(args, argidx, design);
@@ -571,14 +588,14 @@ struct BugpointPass : public Pass {
 			log_cmd_error("This command only operates on fully selected designs!\n");
 
 		RTLIL::Design *crashing_design = clean_design(design, clean);
-		int retval = run_yosys(crashing_design, runner, yosys_cmd, yosys_arg, check_err);
+		int retval = run_yosys(crashing_design, runner, yosys_cmd, yosys_arg, suffix, check_err);
 		if (flag_expect_return && retval != expect_return_value)
 			log_cmd_error("The provided script file or command and Yosys binary returned value %d instead of expected %d on this design!\n", retval, expect_return_value);
 		if (!flag_expect_return && retval == 0)
 			log_cmd_error("The provided script file or command and Yosys binary do not crash on this design!\n");
-		if (!check_logfile(grep))
+		if (!check_logfile(grep, suffix))
 			log_cmd_error("The provided grep string is not found in the log file!\n");
-		if (!check_logfile(err_grep, true))
+		if (!check_logfile(err_grep, suffix, true))
 			log_cmd_error("The provided grep string is not found in stderr log!\n");
 
 		int seed = 0;
@@ -592,30 +609,30 @@ struct BugpointPass : public Pass {
 				if (clean)
 				{
 					RTLIL::Design *testcase = clean_design(simplified);
-					retval = run_yosys(testcase, runner, yosys_cmd, yosys_arg, check_err);
+					retval = run_yosys(testcase, runner, yosys_cmd, yosys_arg, suffix, check_err);
 					delete testcase;
 				}
 				else
 				{
-					retval = run_yosys(simplified, runner, yosys_cmd, yosys_arg, check_err);
+					retval = run_yosys(simplified, runner, yosys_cmd, yosys_arg, suffix, check_err);
 				}
 
 				bool crashes = false;
-				if (flag_expect_return && retval == expect_return_value && check_logfiles(grep, err_grep))
+				if (flag_expect_return && retval == expect_return_value && check_logfiles(grep, err_grep, suffix))
 				{
 					log("Testcase matches expected crash.\n");
 					crashes = true;
 				}
 				else if (!flag_expect_return && retval == 0)
 					log("Testcase does not crash.\n");
-				else if (!flag_expect_return && check_logfiles(grep, err_grep))
+				else if (!flag_expect_return && check_logfiles(grep, err_grep, suffix))
 				{
 					log("Testcase crashes.\n");
 					crashes = true;
 				}
 				else
-					// flag_expect_return && !(retval == expect_return_value && check_logfiles(grep, err_grep))
-					// !flag_expect_return && !(retval == 0 && check_logfiles(grep, err_grep))
+					// flag_expect_return && !(retval == expect_return_value && check_logfiles(grep, err_grep, suffix))
+					// !flag_expect_return && !(retval == 0 && check_logfiles(grep, err_grep, suffix))
 					log("Testcase does not match expected crash.\n");
 
 				if (crashes)

From 20b0ab26b1d26b3a50a50640197b9e3ea874dffb Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Fri, 16 May 2025 16:55:54 +1200
Subject: [PATCH 11/11] tests/bugpoint: More tests

More coverage.
---
 tests/bugpoint/.gitignore                 |  4 +-
 tests/bugpoint/failures.ys                | 29 ++++++++
 tests/bugpoint/mod_constraints.ys         | 83 +++++++++++++++++++++++
 tests/bugpoint/mods.il                    | 38 +++++++++++
 tests/bugpoint/proc_constraints.ys        | 49 +++++++++++++
 tests/bugpoint/procs.il                   | 42 ++++++++++++
 tests/bugpoint/{err.ys => raise_error.ys} |  8 +--
 7 files changed, 248 insertions(+), 5 deletions(-)
 create mode 100644 tests/bugpoint/failures.ys
 create mode 100644 tests/bugpoint/mod_constraints.ys
 create mode 100644 tests/bugpoint/mods.il
 create mode 100644 tests/bugpoint/proc_constraints.ys
 create mode 100644 tests/bugpoint/procs.il
 rename tests/bugpoint/{err.ys => raise_error.ys} (71%)

diff --git a/tests/bugpoint/.gitignore b/tests/bugpoint/.gitignore
index 818575593..1012c66cc 100644
--- a/tests/bugpoint/.gitignore
+++ b/tests/bugpoint/.gitignore
@@ -1,3 +1,5 @@
-*.il
+bugpoint-case.*
 *.log
 *.err
+*.temp
+run-test.mk
diff --git a/tests/bugpoint/failures.ys b/tests/bugpoint/failures.ys
new file mode 100644
index 000000000..ce8daa8cc
--- /dev/null
+++ b/tests/bugpoint/failures.ys
@@ -0,0 +1,29 @@
+write_file fail.temp << EOF
+logger -expect error "Missing -script or -command option." 1
+bugpoint -suffix fail -yosys ../../yosys
+EOF
+exec -expect-return 0 -- ../../yosys -qq mods.il -s fail.temp
+
+write_file fail.temp << EOF
+logger -expect error "do not crash on this design" 1
+bugpoint -suffix fail -yosys ../../yosys -command "dump"
+EOF
+exec -expect-return 0 -- ../../yosys -qq mods.il -s fail.temp
+
+write_file fail.temp << EOF
+logger -expect error "returned value 3 instead of expected 7" 1
+bugpoint -suffix fail -yosys ../../yosys -command raise_error -expect-return 7
+EOF
+exec -expect-return 0 -- ../../yosys -qq mods.il -s fail.temp
+
+write_file fail.temp << EOF
+logger -expect error "not found in the log file!" 1
+bugpoint -suffix fail -yosys ../../yosys -command raise_error -grep "nope"
+EOF
+exec -expect-return 0 -- ../../yosys -qq mods.il -s fail.temp
+
+write_file fail.temp << EOF
+logger -expect error "not found in stderr log!" 1
+bugpoint -suffix fail -yosys ../../yosys -command raise_error -err-grep "nope"
+EOF
+exec -expect-return 0 -- ../../yosys -qq mods.il -s fail.temp
diff --git a/tests/bugpoint/mod_constraints.ys b/tests/bugpoint/mod_constraints.ys
new file mode 100644
index 000000000..f35095510
--- /dev/null
+++ b/tests/bugpoint/mod_constraints.ys
@@ -0,0 +1,83 @@
+read_rtlil mods.il
+select -assert-count 7 w:*
+select -assert-mod-count 3 =*
+select -assert-count 4 c:*
+design -stash base
+
+# everything is removed by default
+design -load base
+bugpoint -suffix mods -yosys ../../yosys -command raise_error -expect-return 3
+select -assert-count 1 w:*
+select -assert-mod-count 1 =*
+select -assert-none c:*
+
+# don't remove wires
+design -load base
+bugpoint -suffix mods -yosys ../../yosys -command raise_error -expect-return 3 -modules -cells
+select -assert-count 3 w:*
+select -assert-mod-count 1 =*
+select -assert-none c:*
+
+# don't remove cells or their connections
+design -load base
+bugpoint -suffix mods -yosys ../../yosys -command raise_error -expect-return 3 -wires -modules
+select -assert-count 5 w:*
+select -assert-mod-count 1 =*
+select -assert-count 4 c:*
+
+# don't remove cells but do remove their connections
+design -load base
+bugpoint -suffix mods -yosys ../../yosys -command raise_error -expect-return 3 -wires -modules -connections
+select -assert-count 1 w:*
+select -assert-mod-count 1 =*
+select -assert-count 4 c:*
+
+# don't remove modules
+design -load base
+bugpoint -suffix mods -yosys ../../yosys -command raise_error -expect-return 3 -wires -cells
+select -assert-count 1 w:*
+select -assert-mod-count 3 =*
+select -assert-none c:*
+
+# can keep wires
+design -load base
+setattr -set bugpoint_keep 1 w:w_b
+bugpoint -suffix mods -yosys ../../yosys -command raise_error -expect-return 3
+select -assert-count 2 w:*
+select -assert-mod-count 1 =*
+select -assert-none c:*
+
+# a wire with keep won't keep the cell/module containing it
+design -load base
+setattr -set bugpoint_keep 1 w:w_o
+bugpoint -suffix mods -yosys ../../yosys -command raise_error -expect-return 3
+select -assert-count 1 w:*
+select -assert-mod-count 1 =*
+select -assert-none c:*
+
+# can keep cells (and do it without the associated module)
+design -load base
+setattr -set bugpoint_keep 1 c:c_a
+bugpoint -suffix mods -yosys ../../yosys -command raise_error -expect-return 3
+select -assert-count 1 w:*
+select -assert-mod-count 1 =*
+select -assert-count 1 c:*
+
+# can keep modules
+design -load base
+setattr -mod -set bugpoint_keep 1 m_a
+bugpoint -suffix mods -yosys ../../yosys -command raise_error -expect-return 3
+select -assert-count 1 w:*
+select -assert-mod-count 2 =*
+select -assert-none c:*
+
+# minimize to just the path connecting w_a and w_c
+# which happens via w_b, w_i, w_o, m_a, c_a and c_b
+write_file script.temp << EOF
+select -assert-none w:w_a %co* w:w_c %ci* %i
+EOF
+design -load base
+bugpoint -suffix mods -yosys ../../yosys -script script.temp -grep "Assertion failed"
+select -assert-count 5 w:*
+select -assert-mod-count 2 =*
+select -assert-count 2 c:*
diff --git a/tests/bugpoint/mods.il b/tests/bugpoint/mods.il
new file mode 100644
index 000000000..fe3ce6522
--- /dev/null
+++ b/tests/bugpoint/mods.il
@@ -0,0 +1,38 @@
+module \m_a
+    wire input 1 \w_i
+    wire output 2 \w_o
+    connect \w_o \w_i
+end
+
+module \m_b
+    wire input 1 \w_i
+    wire output 2 \w_o
+end
+
+attribute \top 1
+module \top
+    attribute \raise_error 3
+    wire \w_a
+    wire \w_b
+    wire \w_c
+
+    cell \m_a \c_a
+        connect \w_i \w_a
+        connect \w_o \w_b
+    end
+
+    cell \m_a \c_b
+        connect \w_i \w_b
+        connect \w_o \w_c
+    end
+
+    cell \m_b \c_c
+        connect \w_i \w_c
+        connect \w_o \w_a
+    end
+
+    cell \m_b \c_d
+        connect \w_i 1'0
+        connect \w_o 1'1
+    end
+end
diff --git a/tests/bugpoint/proc_constraints.ys b/tests/bugpoint/proc_constraints.ys
new file mode 100644
index 000000000..22b8b3c60
--- /dev/null
+++ b/tests/bugpoint/proc_constraints.ys
@@ -0,0 +1,49 @@
+read_rtlil procs.il
+select -assert-count 2 p:*
+design -stash err_q
+
+# processes get removed by default
+design -load err_q
+bugpoint -suffix procs -yosys ../../yosys -command raise_error -expect-return 4
+select -assert-none p:*
+
+# individual processes can be kept
+design -load err_q
+setattr -set bugpoint_keep 1 p:proc_a
+bugpoint -suffix procs -yosys ../../yosys -command raise_error -expect-return 4
+select -assert-count 1 p:*
+
+# all processes can be kept
+design -load err_q
+bugpoint -suffix procs -yosys ../../yosys -command raise_error -expect-return 4 -wires
+select -assert-count 2 p:*
+
+# d and clock are connected after proc
+design -load err_q
+proc
+select -assert-count 3 w:d %co
+select -assert-count 3 w:clock %co
+
+# no assigns means no d
+design -load err_q
+bugpoint -suffix procs -yosys ../../yosys -command raise_error -expect-return 4 -assigns
+proc
+select -assert-count 1 w:d %co
+
+# no updates means no clock
+design -load err_q
+bugpoint -suffix procs -yosys ../../yosys -command raise_error -expect-return 4 -updates
+proc
+select -assert-count 1 w:clock %co
+
+# can remove ports
+design -load err_q
+select -assert-count 5 x:*
+bugpoint -suffix procs -yosys ../../yosys -command raise_error -expect-return 4 -ports
+select -assert-none x:*
+
+# can keep ports
+design -load err_q
+setattr -set bugpoint_keep 1 i:d o:q
+bugpoint -suffix procs -yosys ../../yosys -command raise_error -expect-return 4 -ports
+select -assert-count 2 x:*
diff --git a/tests/bugpoint/procs.il b/tests/bugpoint/procs.il
new file mode 100644
index 000000000..cb9f7c8dd
--- /dev/null
+++ b/tests/bugpoint/procs.il
@@ -0,0 +1,42 @@
+module \ff_with_en_and_sync_reset
+  wire $0\q[1:1]
+  wire $0\q[0:0]
+  attribute \raise_error 4
+  wire width 2 output 5 \q
+  wire width 2 input 4 \d
+  wire input 3 \enable
+  wire input 2 \reset
+  wire input 1 \clock
+
+  process \proc_a
+    assign $0\q[0:0] \q [0]
+    switch \reset
+      case 1'1
+        assign $0\q[0:0] 1'0
+      case 
+        switch \enable
+          case 1'1
+            assign $0\q[0:0] \d [0]
+          case 
+        end
+    end
+    sync posedge \clock
+      update \q [0] $0\q[0:0]
+  end
+
+  process \proc_b
+    assign $0\q[1:1] \q [1]
+    switch \reset
+      case 1'1
+        assign $0\q[1:1] 1'0
+      case 
+        switch \enable
+          case 1'1
+            assign $0\q[1:1] \d [1]
+          case 
+        end
+    end
+    sync posedge \clock
+      update \q [1] $0\q[1:1]
+  end
+end
diff --git a/tests/bugpoint/err.ys b/tests/bugpoint/raise_error.ys
similarity index 71%
rename from tests/bugpoint/err.ys
rename to tests/bugpoint/raise_error.ys
index 42e84241c..a0a03f447 100644
--- a/tests/bugpoint/err.ys
+++ b/tests/bugpoint/raise_error.ys
@@ -16,14 +16,14 @@ design -stash read
 
 # raise_error with int exits with status
 design -load read
-bugpoint -yosys ../../yosys -command raise_error -expect-return 7
+bugpoint -suffix error -yosys ../../yosys -command raise_error -expect-return 7
 select -assert-mod-count 1 =*
 select -assert-mod-count 1 top
 
 # raise_error with string prints message and exits with 1
 design -load read
 rename top abc
-bugpoint -yosys ../../yosys -command raise_error -grep "help me" -expect-return 1
+bugpoint -suffix error -yosys ../../yosys -command raise_error -grep "help me" -expect-return 1
 select -assert-mod-count 1 =*
 select -assert-mod-count 1 other
 
@@ -31,13 +31,13 @@ select -assert-mod-count 1 other
 design -load read
 rename def zzy
 delete other
-bugpoint -yosys ../../yosys -command raise_error -expect-return 1
+bugpoint -suffix error -yosys ../../yosys -command raise_error -expect-return 1
 select -assert-mod-count 1 =*
 select -assert-mod-count 1 zzy
 
 # raise_error -stderr prints to stderr and exits with 1
 design -load read
 rename top abc
-bugpoint -yosys ../../yosys -command "raise_error -stderr" -err-grep "help me" -expect-return 1
+bugpoint -suffix error -yosys ../../yosys -command "raise_error -stderr" -err-grep "help me" -expect-return 1
 select -assert-mod-count 1 =*
 select -assert-mod-count 1 other