builtin: Expands string.h / stdint.h

Declares UINT8_MAX, INT8_MAX and defines strnlen(), strncpy(), strncmp() &
memchr(). Needed by a module I'm integrating into cr51.

BRANCH=none
BUG=none
TEST=make buildall -j

Change-Id: I894b0297216df1b945b36fc77cd3bc5c4ef8aa2b
Signed-off-by: Nadim Taha <ntaha@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/436786
Reviewed-by: Randall Spangler <rspangler@chromium.org>

5 files changed, 119 insertions, 0 deletions

diff --git a/builtin/stdint.h b/builtin/stdint.h
index f80a46f1a5..b82268b409 100644
--- a/builtin/stdint.h
+++ b/builtin/stdint.h
@@ -23,6 +23,13 @@ typedef unsigned int       uintptr_t;
 
 typedef uint8_t            uint_least8_t;
 
+#ifndef UINT8_MAX
+#define UINT8_MAX (255U)
+#endif
+#ifndef INT8_MAX
+#define INT8_MAX (127U)
+#endif
+
 #ifndef UINT16_MAX
 #define UINT16_MAX (65535U)
 #endif
diff --git a/builtin/string.h b/builtin/string.h
index 50a6d54664..21159a5eef 100644
--- a/builtin/string.h
+++ b/builtin/string.h
@@ -14,5 +14,10 @@ int memcmp(const void *s1, const void *s2, size_t len);
 void *memcpy(void *dest, const void *src, size_t len);
 void *memmove(void *dest, const void *src, size_t n);
 void *memset(void *dest, int c, size_t len);
+void *memchr(const void *buffer, int c, size_t n);
+
+size_t strnlen(const char *s, size_t maxlen);
+char *strncpy(char *dest, const char *src, size_t n);
+int strncmp(const char *s1, const char *s2, size_t n);
 
 #endif /* __CROS_EC_STRINGS_H__ */
diff --git a/common/util.c b/common/util.c
index e1b523de97..042523d2b9 100644
--- a/common/util.c
+++ b/common/util.c
@@ -18,6 +18,18 @@ int strlen(const char *s)
 }
 
 
+size_t strnlen(const char *s, size_t maxlen)
+{
+	size_t len = 0;
+
+	while (len < maxlen && *s) {
+		s++;
+		len++;
+	}
+	return len;
+}
+
+
 int isspace(int c)
 {
 	return c == ' ' || c == '\t' || c == '\r' || c == '\n';
@@ -49,6 +61,7 @@ int tolower(int c)
 int strcasecmp(const char *s1, const char *s2)
 {
 	int diff;
+
 	do {
 		diff = tolower(*s1) - tolower(*s2);
 		if (diff)
@@ -310,6 +323,20 @@ void *memmove(void *dest, const void *src, size_t len)
 }
 
 
+void *memchr(const void *buffer, int c, size_t n)
+{
+	char *current = (char *)buffer;
+	char *end = current + n;
+
+	while (current != end) {
+		if (*current == c)
+			return current;
+		current++;
+	}
+	return NULL;
+}
+
+
 void reverse(void *dest, size_t len)
 {
 	int i;
@@ -339,6 +366,35 @@ char *strzcpy(char *dest, const char *src, int len)
 }
 
 
+char *strncpy(char *dest, const char *src, size_t n)
+{
+	char *d = dest;
+
+	while (n && *src) {
+		*d++ = *src++;
+		n--;
+	}
+	if (n)
+		*d = '\0';
+	return dest;
+}
+
+
+int strncmp(const char *s1, const char *s2, size_t n)
+{
+	while (n--) {
+		if (*s1 != *s2)
+			return *s1 - *s2;
+		if (!*s1)
+			break;
+		s1++;
+		s2++;
+
+	}
+	return 0;
+}
+
+
 int uint64divmod(uint64_t *n, int d)
 {
 	uint64_t q = 0, mask;
diff --git a/include/util.h b/include/util.h
index e031148e45..62c9bceb25 100644
--- a/include/util.h
+++ b/include/util.h
@@ -69,9 +69,13 @@ int memcmp(const void *s1, const void *s2, size_t len);
 void *memcpy(void *dest, const void *src, size_t len);
 __visible void *memset(void *dest, int c, size_t len);
 void *memmove(void *dest, const void *src, size_t len);
+void *memchr(const void *buffer, int c, size_t n);
 int strcasecmp(const char *s1, const char *s2);
 int strncasecmp(const char *s1, const char *s2, size_t size);
 int strlen(const char *s);
+size_t strnlen(const char *s, size_t maxlen);
+char *strncpy(char *dest, const char *src, size_t n);
+int strncmp(const char *s1, const char *s2, size_t n);
 
 /* Like strtol(), but for integers. */
 int strtoi(const char *nptr, char **endptr, int base);
diff --git a/test/utils.c b/test/utils.c
index e7de7f8b3d..293c1507c4 100644
--- a/test/utils.c
+++ b/test/utils.c
@@ -231,6 +231,17 @@ static int test_memset(void)
 	return EC_SUCCESS;
 }
 
+static int test_memchr(void)
+{
+	char *buf = "1234";
+
+	TEST_ASSERT(memchr("123", '4', 8) == NULL);
+	TEST_ASSERT(memchr("123", '3', 2) == NULL);
+	TEST_ASSERT(memchr(buf, '3', 8) == buf + 2);
+	TEST_ASSERT(memchr(buf, '4', 4) == buf + 3);
+	return EC_SUCCESS;
+}
+
 static int test_strzcpy(void)
 {
 	char dest[10];
@@ -245,11 +256,43 @@ static int test_strzcpy(void)
 	return EC_SUCCESS;
 }
 
+static int test_strncpy(void)
+{
+	char dest[10];
+
+	strncpy(dest, "test", 10);
+	TEST_ASSERT_ARRAY_EQ("test", dest, 5);
+	strncpy(dest, "12345", 6);
+	TEST_ASSERT_ARRAY_EQ("12345", dest, 6);
+	strncpy(dest, "testtesttest", 10);
+	TEST_ASSERT_ARRAY_EQ("testtestte", dest, 10);
+
+	return EC_SUCCESS;
+}
+
+static int test_strncmp(void)
+{
+	TEST_ASSERT(strncmp("123", "123", 8) == 0);
+	TEST_ASSERT(strncmp("789", "456", 8) > 0);
+	TEST_ASSERT(strncmp("abc", "abd", 4) < 0);
+	TEST_ASSERT(strncmp("abc", "abd", 2) == 0);
+	return EC_SUCCESS;
+}
+
 static int test_strlen(void)
 {
 	TEST_CHECK(strlen("this is a string") == 16);
 }
 
+static int test_strnlen(void)
+{
+	TEST_ASSERT(strnlen("this is a string", 17) == 16);
+	TEST_ASSERT(strnlen("this is a string", 16) == 16);
+	TEST_ASSERT(strnlen("this is a string", 5) == 5);
+
+	return EC_SUCCESS;
+}
+
 static int test_strcasecmp(void)
 {
 	TEST_CHECK((strcasecmp("test string", "TEST strIng") == 0) &&
@@ -453,8 +496,12 @@ void run_test(void)
 	RUN_TEST(test_memmove);
 	RUN_TEST(test_memcpy);
 	RUN_TEST(test_memset);
+	RUN_TEST(test_memchr);
 	RUN_TEST(test_strzcpy);
+	RUN_TEST(test_strncpy);
+	RUN_TEST(test_strncmp);
 	RUN_TEST(test_strlen);
+	RUN_TEST(test_strnlen);
 	RUN_TEST(test_strcasecmp);
 	RUN_TEST(test_strncasecmp);
 	RUN_TEST(test_atoi);