1 files changed, 110 insertions, 0 deletions
diff --git a/teensy/string0.c b/teensy/string0.c
new file mode 100644
index 0000000000..2a5f255971
--- /dev/null
+++ b/teensy/string0.c
@@ -0,0 +1,110 @@
+#include <stdint.h>
+#include "std.h"
+
+void *memcpy(void *dest, const void *src, size_t n) {
+    // TODO align and copy 32 bits at a time
+    uint8_t *d = dest;
+    const uint8_t *s = src;
+    for (; n > 0; n--) {
+        *d++ = *s++;
+    }
+    return dest;
+}
+
+void *memmove(void *dest, const void *src, size_t n) {
+    if (src < dest && dest < src + n) {
+        // need to copy backwards
+        uint8_t *d = dest + n - 1;
+        const uint8_t *s = src + n - 1;
+        for (; n > 0; n--) {
+            *d-- = *s--;
+        }
+        return dest;
+    } else {
+        // can use normal memcpy
+        return memcpy(dest, src, n);
+    }
+}
+
+void *memset(void *s, int c, size_t n) {
+    uint8_t *s2 = s;
+    for (; n > 0; n--) {
+        *s2++ = c;
+    }
+    return s;
+}
+
+int strlen(const char *str) {
+    int len = 0;
+    for (const char *s = str; *s; s++) {
+        len += 1;
+    }
+    return len;
+}
+
+int strcmp(const char *s1, const char *s2) {
+    while (*s1 && *s2) {
+        char c1 = *s1++; // XXX UTF8 get char, next char
+        char c2 = *s2++; // XXX UTF8 get char, next char
+        if (c1 < c2) return -1;
+        else if (c1 > c2) return 1;
+    }
+    if (*s2) return -1;
+    else if (*s1) return 1;
+    else return 0;
+}
+
+int strncmp(const char *s1, const char *s2, size_t n) {
+    while (*s1 && *s2 && n > 0) {
+        char c1 = *s1++; // XXX UTF8 get char, next char
+        char c2 = *s2++; // XXX UTF8 get char, next char
+        n--;
+        if (c1 < c2) return -1;
+        else if (c1 > c2) return 1;
+    }
+    if (n == 0) return 0;
+    else if (*s2) return -1;
+    else if (*s1) return 1;
+    else return 0;
+}
+
+char *strndup(const char *s, size_t n) {
+    size_t len = strlen(s);
+    if (n > len) {
+        n = len;
+    }
+    char *s2 = malloc(n + 1);
+    memcpy(s2, s, n);
+    s2[n] = '\0';
+    return s2;
+}
+
+char *strcpy(char *dest, const char *src) {
+    char *d = dest;
+    while (*src) {
+        *d++ = *src++;
+    }
+    *d = '\0';
+    return dest;
+}
+
+// needed because gcc optimises strcpy + strcat to this
+char *stpcpy(char *dest, const char *src) {
+    while (*src) {
+        *dest++ = *src++;
+    }
+    *dest = '\0';
+    return dest;
+}
+
+char *strcat(char *dest, const char *src) {
+    char *d = dest;
+    while (*d) {
+        d++;
+    }
+    while (*src) {
+        *d++ = *src++;
+    }
+    *d = '\0';
+    return dest;
+}