From 555fa197730c061bbf0ab01334e99bc47fb3dc06 Mon Sep 17 00:00:00 2001
From: pwpiwi <pwpiwi@users.noreply.github.com>
Date: Mon, 25 Jan 2021 09:27:38 +0100
Subject: [PATCH] Cleanup armsrc/string.c and string.h (#964)

- remove unnecessary memxor(), strreverse(), and itoa() functions
- Use correct types in function declarations and definitions
- add memmove() function. Gcc may generate calls to memcmp(), memcpy(), memset() and memmove()
---
 armsrc/string.c | 80 ++++++++++++++++++++-----------------------------
 armsrc/string.h | 15 ++++------
 2 files changed, 38 insertions(+), 57 deletions(-)

diff --git a/armsrc/string.c b/armsrc/string.c
index 945a4cf6..b2710d07 100644
--- a/armsrc/string.c
+++ b/armsrc/string.c
@@ -11,8 +11,7 @@
 #include "string.h"
 #include <stdint.h>
 
-void *memcpy(void *dest, const void *src, int len)
-{
+void *memcpy(void *dest, const void *src, size_t len) {
 	uint8_t *d = dest;
 	const uint8_t *s = src;
 	while((len--) > 0) {
@@ -23,8 +22,8 @@ void *memcpy(void *dest, const void *src, int len)
 	return dest;
 }
 
-void *memset(void *dest, int c, int len)
-{
+
+void *memset(void *dest, int c, size_t len) {
 	uint8_t *d = dest;
 	while((len--) > 0) {
 		*d = c;
@@ -33,8 +32,30 @@ void *memset(void *dest, int c, int len)
 	return dest;
 }
 
-int memcmp(const void *av, const void *bv, int len)
-{
+
+void *memmove(void *dest, const void *src, size_t len) {
+	uint8_t *d = dest;
+	const uint8_t *s = src;
+	if (dest <= src) {
+		while((len--) > 0) {
+			*d = *s;
+			d++;
+			s++;
+		} 
+	} else {
+		d = d + len - 1;
+		s = s + len - 1;
+		while((len--) > 0) {
+			*d = *s;
+			d--;
+			s--;
+		}
+	}
+	return dest;
+}
+
+
+int memcmp(const void *av, const void *bv, size_t len) {
 	const uint8_t *a = av;
 	const uint8_t *b = bv;
 
@@ -48,13 +69,8 @@ int memcmp(const void *av, const void *bv, int len)
 	return 0;
 }
 
-void memxor(uint8_t * dest, uint8_t * src, size_t len) {
-   for( ; len > 0; len--,dest++,src++)
-       *dest ^= *src;
-}
 
-int strlen(const char *str)
-{
+size_t strlen(const char *str) {
 	int l = 0;
 	while(*str) {
 		l++;
@@ -63,8 +79,8 @@ int strlen(const char *str)
 	return l;
 }
 
-char* strncat(char *dest, const char *src, unsigned int n)
-{
+
+char* strncat(char *dest, const char *src, size_t n) {
 	unsigned int dest_len = strlen(dest);
 	unsigned int i;
 
@@ -75,8 +91,8 @@ char* strncat(char *dest, const char *src, unsigned int n)
 	return dest;
 }
 
-char* strcat(char *dest, const char *src)
-{
+
+char* strcat(char *dest, const char *src) {
 	unsigned int dest_len = strlen(dest);
 	unsigned int i;
 
@@ -86,35 +102,3 @@ char* strcat(char *dest, const char *src)
 
 	return dest;
 }
-////////////////////////////////////////// code to do 'itoa'
-
-/* reverse:  reverse string s in place */
-void strreverse(char s[])
-{
-    int c, i, j;
-
-    for (i = 0, j = strlen(s)-1; i<j; i++, j--) {
-        c = s[i];
-        s[i] = s[j];
-        s[j] = c;
-    }
-}
-
-/* itoa:  convert n to characters in s */
-void itoa(int n, char s[])
-{
-    int i, sign;
-
-    if ((sign = n) < 0)  /* record sign */
-        n = -n;          /* make n positive */
-    i = 0;
-    do {       /* generate digits in reverse order */
-        s[i++] = n % 10 + '0';   /* get next digit */
-    } while ((n /= 10) > 0);     /* delete it */
-    if (sign < 0)
-        s[i++] = '-';
-    s[i] = '\0';
-    strreverse(s);
-}
-
-//////////////////////////////////////// END 'itoa' CODE
diff --git a/armsrc/string.h b/armsrc/string.h
index 07ac112f..dd90c7bc 100644
--- a/armsrc/string.h
+++ b/armsrc/string.h
@@ -15,15 +15,12 @@
 #include <stdint.h>
 #include "util.h"
 
-int strlen(const char *str);
-RAMFUNC void *memcpy(void *dest, const void *src, int len);
-void *memset(void *dest, int c, int len);
-RAMFUNC int memcmp(const void *av, const void *bv, int len);
-void memxor(uint8_t * dest, uint8_t * src, size_t len);
-char *strncat(char *dest, const char *src, unsigned int n);
+RAMFUNC void *memcpy(void *dest, const void *src, size_t len);
+void *memset(void *dest, int c, size_t len);
+void *memmove(void *dest, const void *src, size_t len);
+RAMFUNC int memcmp(const void *av, const void *bv, size_t len);
+size_t strlen(const char *str);
+char *strncat(char *dest, const char *src, size_t n);
 char *strcat(char *dest, const char *src);
-void strreverse(char s[]);
-void itoa(int n, char s[]);
-
 
 #endif /* __STRING_H */
-- 
2.39.5