Added negative test scenarios

runtime/Makefile

@@ -9,6 +9,15 @@ INVARIANTS_CHECK_FLAGS=$(TEST_FLAGS) -DFULL_INVARIANT_CHECKS
 all: gc.o runtime.o
 	ar rc runtime.a runtime.o gc.o
 
+NEGATIVE_TESTS=$(sort $(basename $(notdir $(wildcard negative_scenarios/*_neg.c))))
+
+$(NEGATIVE_TESTS): %: negative_scenarios/%.c
+	@echo "Running test $@"
+	@$(CC) -o $@.o $(COMMON_FLAGS) negative_scenarios/$@.c gc.c
+	@./$@.o 2> negative_scenarios/$@.err || diff negative_scenarios/$@.err negative_scenarios/expected/$@.err
+
+negative_tests: $(NEGATIVE_TESTS)
+
 # this is a target that runs unit tests, scenarios are written in a single file `test_main.c`
 unit_tests.o: gc.c gc.h runtime.c runtime.h runtime_common.h virt_stack.c virt_stack.h test_main.c test_util.s
 	$(CC) -o unit_tests.o $(UNIT_TESTS_FLAGS) gc.c virt_stack.c runtime.c test_main.c test_util.s
@@ -32,4 +41,4 @@ runtime.o: runtime.c runtime.h
 	$(CC) $(PROD_FLAGS) -c runtime.c
 
 clean:
-	$(RM) *.a *.o *~
+	$(RM) *.a *.o *~ negative_scenarios/*.err

runtime/negative_scenarios/expected/extra_roots_empty_pop_neg.err

@@ -0,0 +1,2 @@
+ERROR: pop_extra_root: extra_roots are empty
+: Success

runtime/negative_scenarios/expected/extra_roots_overflow_neg.err

@@ -0,0 +1,2 @@
+ERROR: push_extra_roots: extra_roots_pool overflow
+: Success

runtime/negative_scenarios/expected/extra_roots_pop_mismatch_neg.err

@@ -0,0 +1,2 @@
+ERROR: pop_extra_root: stack invariant violation
+: Success

runtime/negative_scenarios/extra_roots_empty_pop_neg.c

@@ -0,0 +1,5 @@
+#include "../gc.h"
+
+#include <stddef.h>
+
+int main () { pop_extra_root((void **)NULL); }

runtime/negative_scenarios/extra_roots_overflow_neg.c

@@ -0,0 +1,7 @@
+#include "../gc.h"
+
+#include <stddef.h>
+
+int main () {
+  for (size_t i = 0; i < MAX_EXTRA_ROOTS_NUMBER + 1; ++i) { push_extra_root(NULL); }
+}

runtime/negative_scenarios/extra_roots_pop_mismatch_neg.c

@@ -0,0 +1,6 @@
+#include "../gc.h"
+
+int main () {
+  push_extra_root(NULL);
+  pop_extra_root((void **)239);
+}