string.h: Move common string functions into .c file

There's no clear reason why most of coreboot's basic string functions
are static inline. These functions don't particularly benefit from
inlining (at least not notably more than other functions). This patch
moves them to string.c to be more consistent with our usual coding
practices.

Leaving the ctype functions as static inline because they actually seem
small and collapsible enough that inlining seems reasonable.

Also clarified the situation of strdup() and strconcat() a bit more,
optimized strrchr() to be single-pass, fixed a bug with using strchr()
to find '\0' and got rid of unnecessary register keywords.

Change-Id: I88166ba9876e94dfa3cfc06969c78a9e1bc6fc36
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32901
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Alex Thiessen <alex.thiessen.de+coreboot@gmail.com>

src/include/string.h

@@ -25,33 +25,13 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
 #endif
 char *strdup(const char *s);
 char *strconcat(const char *s1, const char *s2);
-
+size_t strnlen(const char *src, size_t max);
-// simple string functions
+size_t strlen(const char *src);
-
+char *strchr(const char *s, int c);
-static inline size_t strnlen(const char *src, size_t max)
+char *strncpy(char *to, const char *from, int count);
-{
+char *strcpy(char *dst, const char *src);
-	size_t i = 0;
+int strcmp(const char *s1, const char *s2);
-	while ((*src++) && (i < max))
+int strncmp(const char *s1, const char *s2, int maxlen);
-		i++;
-	return i;
-}
-
-static inline size_t strlen(const char *src)
-{
-	size_t i = 0;
-	while (*src++)
-		i++;
-	return i;
-}
-
-static inline char *strchr(const char *s, int c)
-{
-	for (; *s; s++) {
-		if (*s == c)
-			return (char *) s;
-	}
-	return 0;
-}
 
 /**
  * Find a character in a string.
@@ -61,71 +41,14 @@ static inline char *strchr(const char *s, int c)
  * @return A pointer to the last occurrence of the character in the
  * string, or NULL if the character was not encountered within the string.
  */
-static inline char *strrchr(const char *s, int c)
+char *strrchr(const char *s, int c);
-{
-	char *p = (char *)s + strlen(s);
 
-	for (; p >= s; p--) {
+/*
-		if (*p == c)
+ * Parses an unsigned integer and moves the input pointer forward to the first
-			return p;
+ * character that's not a valid digit. s and *s must not be NULL. Result
-	}
+ * undefined if it overruns the return type size.
-
+ */
-	return NULL;
+unsigned int skip_atoi(char **s);
-}
-
-static inline char *strncpy(char *to, const char *from, int count)
-{
-	register char *ret = to;
-	register char data;
-
-	while (count > 0) {
-		count--;
-		data = *from++;
-		*to++  = data;
-		if (data == '\0')
-			break;
-	}
-
-	while (count > 0) {
-		count--;
-		*to++ = '\0';
-	}
-	return ret;
-}
-
-static inline char *strcpy(char *dst, const char *src)
-{
-	char *ptr = dst;
-
-	while (*src)
-		*dst++ = *src++;
-	*dst = '\0';
-
-	return ptr;
-}
-
-static inline int strcmp(const char *s1, const char *s2)
-{
-	int r;
-
-	while ((r = (*s1 - *s2)) == 0 && *s1) {
-		s1++;
-		s2++;
-	}
-	return r;
-}
-
-static inline int strncmp(const char *s1, const char *s2, int maxlen)
-{
-	int i;
-
-	for (i = 0; i < maxlen; i++) {
-		if ((s1[i] != s2[i]) || (s1[i] == '\0'))
-			return s1[i] - s2[i];
-	}
-
-	return 0;
-}
 
 static inline int isspace(int c)
 {
@@ -179,18 +102,4 @@ static inline int tolower(int c)
 	return c;
 }
 
-/*
- * Parses an unsigned integer and moves the input pointer forward to the first
- * character that's not a valid digit. s and *s must not be NULL. Result
- * undefined if it overruns the return type size.
- */
-static inline unsigned int skip_atoi(char **s)
-{
-	unsigned int i = 0;
-
-	while (isdigit(**s))
-		i = i*10 + *((*s)++) - '0';
-	return i;
-}
-
 #endif /* STRING_H */

src/lib/Makefile.inc

@@ -118,7 +118,6 @@ ramstage-y += bootmem.c
 ramstage-y += fmap.c
 ramstage-y += memchr.c
 ramstage-y += memcmp.c
-ramstage-y += string.c
 ramstage-y += malloc.c
 smm-$(CONFIG_SMM_TSEG) += malloc.c
 ramstage-y += dimm_info_util.c
@@ -244,6 +243,14 @@ postcar-y += reset.c
 ramstage-y += reset.c
 smm-y += reset.c
 
+decompressor-y += string.c
+bootblock-y += string.c
+verstage-y += string.c
+romstage-y += string.c
+postcar-y += string.c
+ramstage-y += string.c
+smm-y += string.c
+
 postcar-y += bootmode.c
 postcar-y += boot_device.c
 postcar-y += cbfs.c

src/lib/string.c

@@ -1,9 +1,14 @@
+#include <assert.h>
+#include <rules.h>
 #include <string.h>
 #include <stddef.h>
 #include <stdlib.h>
 
 char *strdup(const char *s)
 {
+	if (!ENV_RAMSTAGE)
+		dead_code();	/* This can't be used without malloc(). */
+
 	size_t sz = strlen(s) + 1;
 	char *d = malloc(sz);
 	if (d)
@@ -13,6 +18,9 @@ char *strdup(const char *s)
 
 char *strconcat(const char *s1, const char *s2)
 {
+	if (!ENV_RAMSTAGE)
+		dead_code();	/* This can't be used without malloc(). */
+
 	size_t sz_1 = strlen(s1);
 	size_t sz_2 = strlen(s2);
 	char *d = malloc(sz_1 + sz_2 + 1);
@@ -22,3 +30,104 @@ char *strconcat(const char *s1, const char *s2)
 	}
 	return d;
 }
+
+size_t strnlen(const char *src, size_t max)
+{
+	size_t i = 0;
+	while ((*src++) && (i < max))
+		i++;
+	return i;
+}
+
+size_t strlen(const char *src)
+{
+	size_t i = 0;
+	while (*src++)
+		i++;
+	return i;
+}
+
+char *strchr(const char *s, int c)
+{
+	do {
+		if (*s == c)
+			return (char *)s;
+	} while (*s++);
+
+	return NULL;
+}
+
+char *strrchr(const char *s, int c)
+{
+	char *p = NULL;
+
+	do {
+		if (*s == c)
+			p = (char *)s;
+	} while (*s++);
+
+	return p;
+}
+
+char *strncpy(char *to, const char *from, int count)
+{
+	char *ret = to;
+	char data;
+
+	while (count > 0) {
+		count--;
+		data = *from++;
+		*to++  = data;
+		if (data == '\0')
+			break;
+	}
+
+	while (count > 0) {
+		count--;
+		*to++ = '\0';
+	}
+	return ret;
+}
+
+char *strcpy(char *dst, const char *src)
+{
+	char *ptr = dst;
+
+	while (*src)
+		*dst++ = *src++;
+	*dst = '\0';
+
+	return ptr;
+}
+
+int strcmp(const char *s1, const char *s2)
+{
+	int r;
+
+	while ((r = (*s1 - *s2)) == 0 && *s1) {
+		s1++;
+		s2++;
+	}
+	return r;
+}
+
+int strncmp(const char *s1, const char *s2, int maxlen)
+{
+	int i;
+
+	for (i = 0; i < maxlen; i++) {
+		if ((s1[i] != s2[i]) || (s1[i] == '\0'))
+			return s1[i] - s2[i];
+	}
+
+	return 0;
+}
+
+unsigned int skip_atoi(char **s)
+{
+	unsigned int i = 0;
+
+	while (isdigit(**s))
+		i = i*10 + *((*s)++) - '0';
+	return i;
+}