add failing test files

where the C compiler should throw compile-time errors
for GH rui314#41

.gitignore

@@ -7,4 +7,5 @@
 /thirdparty
 /chibicc
 /test/*.exe
+/test/*.fail
 /stage2

Makefile

@@ -4,7 +4,9 @@ SRCS=$(wildcard *.c)
 OBJS=$(SRCS:.c=.o)
 
 TEST_SRCS=$(wildcard test/*.c)
+FAIL_TEST_SRCS=$(wildcard test/*.c_fail)
 TESTS=$(TEST_SRCS:.c=.exe)
+FAIL_TESTS=$(FAIL_TEST_SRCS:.c_fail=.fail)
 
 # Stage 1
 
@@ -17,7 +19,12 @@ test/%.exe: chibicc test/%.c
 	./chibicc -Iinclude -Itest -c -o test/$*.o test/$*.c
 	$(CC) -pthread -o $@ test/$*.o -xc test/common
 
-test: $(TESTS)
+test/%.fail: chibicc test/%.c_fail
+	echo "cat <<EOF" >test/$*.fail
+	./chibicc -Iinclude -Itest -xc -c test/$*.c_fail 2>>test/$*.fail || \
+	  (echo OK; printf "EOF\necho OK\n" >>test/$*.fail; chmod +x test/$*.fail)
+
+test: $(TESTS) $(FAIL_TESTS)
 	for i in $^; do echo $$i; ./$$i || exit 1; echo; done
 	test/driver.sh ./chibicc
 
@@ -50,7 +57,7 @@ install:
 	sudo cp chibicc /usr/local/bin/chibicc
 
 clean:
-	rm -rf chibicc tmp* $(TESTS) test/*.s test/*.exe stage2
+	rm -rf chibicc tmp* $(TESTS) test/*.s test/*.exe stage2 test/*.fail
 	find * -type f '(' -name '*~' -o -name '*.o' ')' -exec rm {} ';'
 
 .PHONY: test clean test-stage2

test/void1.c_fail

@@ -0,0 +1,7 @@
+// Assigning expression with void type.
+void foo() {}
+void bar() {int x = foo();}
+
+int main() {
+  return 1;
+}

test/void2.c_fail

@@ -0,0 +1,8 @@
+// Return nothing in a non-void type function.
+int bar() {
+  return;
+}
+
+int main() {
+  return 1;
+}

test/void3.c_fail

@@ -0,0 +1,10 @@
+// Return void type expression in a non-void function.
+void foo() {}
+
+int bar() {
+  return foo();
+}
+
+int main() {
+  return 1;
+}

test/void4.c_fail

@@ -0,0 +1,9 @@
+// Return non-void type expression in a void type function.
+void foo() {
+  return 1;
+}
+
+
+int main() {
+  return 1;
+}