Main: include/kernaux/libc.h: Add libc functions (closes #37)

README.md

@@ -104,10 +104,16 @@ stable options.
   * `--with[out]-libc-atoi`
   * `--with[out]-libc-isdigit`
   * `--with[out]-libc-isspace`
+  * `--with[out]-libc-memcpy`
+  * `--with[out]-libc-memmove`
   * `--with[out]-libc-memset`
+  * `--with[out]-libc-strcmp`
   * `--with[out]-libc-strcpy`
   * `--with[out]-libc-strlen`
+  * `--with[out]-libc-strncmp`
+  * `--with[out]-libc-strncpy`
   * `--with[out]-libc-strnlen`
+  * `--with[out]-libc-strstr`
 
 ### Default options
 

configure.ac

@@ -47,10 +47,16 @@ AC_ARG_WITH(  [libc-all],     AS_HELP_STRING([--with-libc-all],       [with libc
 AC_ARG_WITH(  [libc-atoi],    AS_HELP_STRING([--with-libc-atoi],      [with atoi replacement]))
 AC_ARG_WITH(  [libc-isdigit], AS_HELP_STRING([--with-libc-isdigit],   [with isdigit replacement]))
 AC_ARG_WITH(  [libc-isspace], AS_HELP_STRING([--with-libc-isspace],   [with isspace replacement]))
+AC_ARG_WITH(  [libc-memcpy],  AS_HELP_STRING([--with-libc-memcpy],    [with memcpy replacement]))
+AC_ARG_WITH(  [libc-memmove], AS_HELP_STRING([--with-libc-memmove],   [with memmove replacement]))
 AC_ARG_WITH(  [libc-memset],  AS_HELP_STRING([--with-libc-memset],    [with memset replacement]))
+AC_ARG_WITH(  [libc-strcmp],  AS_HELP_STRING([--with-libc-strcmp],    [with strcmp replacement]))
 AC_ARG_WITH(  [libc-strcpy],  AS_HELP_STRING([--with-libc-strcpy],    [with strcpy replacement]))
 AC_ARG_WITH(  [libc-strlen],  AS_HELP_STRING([--with-libc-strlen],    [with strlen replacement]))
+AC_ARG_WITH(  [libc-strncmp], AS_HELP_STRING([--with-libc-strncmp],   [with strncmp replacement]))
+AC_ARG_WITH(  [libc-strncpy], AS_HELP_STRING([--with-libc-strncpy],   [with strncpy replacement]))
 AC_ARG_WITH(  [libc-strnlen], AS_HELP_STRING([--with-libc-strnlen],   [with strnlen replacement]))
+AC_ARG_WITH(  [libc-strstr],  AS_HELP_STRING([--with-libc-strstr],    [with strstr replacement]))
 
 
 

include/kernaux/libc.h

@@ -15,10 +15,16 @@ int isspace(int c);
 int atoi(const char *str);
 
 // <string.h>
+void *memcpy(void *dest, const void *src, size_t n);
+void *memmove(void *dest, const void *src, size_t n);
 void *memset(void *s, int c, size_t n);
+int strcmp(const char *s1, const char *s2);
 char *strcpy(char *dest, const char *src);
 size_t strlen(const char *s);
+int strncmp(const char *s1, const char *s2, size_t n);
+char *strncpy(char *dest, const char *src, size_t n);
 size_t strnlen(const char *s, size_t maxlen);
+char *strstr(const char *haystack, const char *needle);
 
 #ifdef __cplusplus
 }

src/libc.c

@@ -35,15 +35,49 @@ int isspace(const int c)
 }
 #endif // WITH_LIBC_ISSPACE
 
+#ifdef WITH_LIBC_MEMCPY
+void *memcpy(void *dest, const void *src, size_t n)
+{
+    char *dest_cell = dest;
+    char *src_cell = src;
+    while (n--) *dest_cell++ = *src_cell++;
+    return dest;
+}
+#endif // WITH_LIBC_MEMCPY
+
+#ifdef WITH_LIBC_MEMMOVE
+void *memmove(void *dest, const void *src, size_t n)
+{
+    char *dest_cell = dest;
+    char *src_cell = src;
+    if (dest_cell <= src_cell) {
+        while (n--) *dest_cell++ = *src_cell++;
+    } else {
+        dest_cell += n;
+        src_cell += n;
+        while (n--) *--dest_cell = *--src_cell;
+    }
+    return dest;
+}
+#endif // WITH_LIBC_MEMMOVE
+
 #ifdef WITH_LIBC_MEMSET
 void *memset(void *s, int c, size_t n)
 {
     char *ss = s;
-    while (n-- > 0) *ss++ = c;
+    while (n--) *ss++ = c;
     return s;
 }
 #endif // WITH_LIBC_MEMSET
 
+#ifdef WITH_LIBC_STRCMP
+int strcmp(const char *s1, const char *s2)
+{
+    for (; *s1; ++s1, ++s2) if (*s1 != *s2) return *s1 < *s2 ? -1 : 1;
+    return 0;
+}
+#endif // WITH_LIBC_STRCMP
+
 #ifdef WITH_LIBC_STRCPY
 char *strcpy(char *dest, const char *src)
 {
@@ -62,6 +96,23 @@ size_t strlen(const char *s)
 }
 #endif // WITH_LIBC_STRLEN
 
+#ifdef WITH_LIBC_STRNCMP
+int strncmp(const char *s1, const char *s2, size_t n)
+{
+    for (; *s1 && n; ++s1, ++s2, --n) if (*s1 != *s2) return *s1 < *s2 ? -1 : 1;
+    return 0;
+}
+#endif // WITH_LIBC_STRNCMP
+
+#ifndef WITH_LIBC_STRNCPY
+char *strncpy(char *dest, const char *src, size_t n)
+{
+    char *tmp = dest;
+    while (n-- && (*dest++ = *src++) != '\0');
+    return tmp;
+}
+#endif // WITH_LIBC_STRNCPY
+
 #ifdef WITH_LIBC_STRNLEN
 size_t strnlen(const char *s, size_t maxlen)
 {
@@ -70,3 +121,20 @@ size_t strnlen(const char *s, size_t maxlen)
     return ss - s;
 }
 #endif // WITH_LIBC_STRNLEN
+
+#ifdef WITH_LIBC_STRSTR
+char *strstr(const char *haystack, const char *needle)
+{
+    const size_t needle_slen = strlen(needle);
+    if (!needle_slen) return (char*)haystack;
+
+    size_t haystack_slen = strlen(haystack);
+    while (haystack_slen >= needle_slen) {
+        --haystack_slen;
+        if (!memcmp(haystack, needle, needle_slen)) return (char*)haystack;
+        ++haystack;
+    }
+
+    return NULL;
+}
+#endif // WITH_LIBC_STRSTR