7 files changed, 28 insertions, 48 deletions
diff --git a/signal.c b/signal.c
index 4e0d9be..d2c96e2 100644
--- a/signal.c
+++ b/signal.c
@@ -1,10 +1,10 @@
 #include <signal.h>
 #include "test.h"
 
+sig_atomic_t test_sig_atomic = 0;
+
 void test_signal_h(void)
 {
-	sig_atomic_t sig_atomic = 0;
-
 	int signals[] = {
 		SIGABRT,
 		SIGFPE,
@@ -14,8 +14,6 @@ void test_signal_h(void)
 		SIGTERM,
 	};
 
-	(void)sig_atomic;
-
 	testing_header("signal.h");
 
 	test_distinct(signals);
diff --git a/stddef.c b/stddef.c
index 575881d..43ab2d8 100644
--- a/stddef.c
+++ b/stddef.c
@@ -6,18 +6,14 @@ struct s {
 	char b;
 };
 
+ptrdiff_t test_ptrdiff;
+size_t test_size;
+wchar_t test_wchar;
+
 void test_stddef_h(void)
 {
-	ptrdiff_t ptrdiff;
-	size_t size;
-	wchar_t wchar;
-
 	static struct s the_s;
 
-	(void)ptrdiff;
-	(void)size;
-	(void)wchar;
-
 	testing_header("stddef.h");
 
 	test_true(NULL == 0);
diff --git a/stdio.c b/stdio.c
index cf5d6ac..49a0a3b 100644
--- a/stdio.c
+++ b/stdio.c
@@ -2,15 +2,12 @@
 #include "_stdio.h"
 #include "test.h"
 
+FILE *test_file;
+fpos_t test_fpos;
+size_t test_size;
+
 void test_stdio_h(void)
 {
-	FILE *file;
-	fpos_t fpos;
-	size_t size;
-	(void)file;
-	(void)fpos;
-	(void)size;
-
 	int buftypes[] = {
 		_IOFBF,
 		_IOLBF,
diff --git a/stdlib.c b/stdlib.c
index 9e09111..954031e 100644
--- a/stdlib.c
+++ b/stdlib.c
@@ -2,17 +2,13 @@
 #include <limits.h>
 #include "test.h"
 
+div_t test_div;
+ldiv_t test_ldiv;
+size_t test_size;
+wchar_t test_wchar;
+
 void test_stdlib_h(void)
 {
-	div_t div;
-	ldiv_t ldiv;
-	size_t size;
-	wchar_t wchar;
-	(void)div;
-	(void)ldiv;
-	(void)size;
-	(void)wchar;
-
 	int exit_statuses[] = {
 		EXIT_FAILURE,
 		EXIT_SUCCESS,
diff --git a/string.c b/string.c
index 5b476d7..f1174ec 100644
--- a/string.c
+++ b/string.c
@@ -1,14 +1,14 @@
 #include <string.h>
 #include "test.h"
 
+size_t test_size;
+
 void test_string_h(void)
 {
-	size_t size;
 	char dst[64] = { 0 };
 	char less[] = "a";
 	char more[] = "b";
 	char haystack[] = "the five boxing wizards jump quickly";
-	(void)size;
 
 	testing_header("string.h");
 
@@ -60,6 +60,7 @@ void test_string_h(void)
 	test_true(strspn(haystack, "12345") == 0);
 	test_true(strspn(haystack, "eht") == 3);
 
+	test_true(strstr(haystack, "") == haystack);
 	test_true(strstr(haystack, "wizard") == haystack + 16);
 	test_true(strstr(haystack, "rogue") == NULL);
 
diff --git a/wchar.c b/wchar.c
index 525d562..137e218 100644
--- a/wchar.c
+++ b/wchar.c
@@ -3,19 +3,14 @@
 #include "_wchar.h"
 #include "test.h"
 
+wchar_t test_wchar;
+size_t test_size;
+mbstate_t test_mbstate;
+wint_t test_wint;
+struct tm *test_tm;
+
 void test_wchar_h(void)
 {
-	wchar_t wchar;
-	size_t size;
-	mbstate_t mbstate;
-	wint_t wint;
-	struct tm *tm;
-	(void)wchar;
-	(void)size;
-	(void)mbstate;
-	(void)wint;
-	(void)tm;
-
 	testing_header("wchar.h");
 
 	test_true(NULL == 0);
diff --git a/wctype.c b/wctype.c
index 9bb4f02..0238140 100644
--- a/wctype.c
+++ b/wctype.c
@@ -5,6 +5,10 @@
 #include "_wctype.h"
 #include "test.h"
 
+wint_t test_wint;
+wctrans_t test_wctrans;
+wctype_t test_wctype;
+
 #define UPPER L"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 #define LOWER L"abcdefghijklmnopqrstuvwxyz"
 #define DIGIT L"0123456789"
@@ -68,13 +72,6 @@ static void test_ctype_conversion_imp(const char *fnname, int (*fn)(int), const
 
 void test_wctype_h(void)
 {
-	wint_t wint;
-	wctrans_t wctrans;
-	wctype_t wctype;
-	(void)wint;
-	(void)wctrans;
-	(void)wctype;
-
 	testing_header("wctype.h");
 
 	test_ctype_function(iswalnum, UPPER LOWER DIGIT);