Rewrite the wrappers of strncpy & strncat:

Add one argument about the allocation of the dest buffer
Theses wrappers are internal (so no impact to API)
and only used in a few place in m-string.
This make the wrappers able to use the function
strncpy_s & strncat_s for MSVC rather than using
reimplementation of the original functions.

Author: P-p-H-d

m-core.h

@@ -1756,41 +1756,15 @@ m_core_fopen(const char filename[], const char opt[])
     if (err) return NULL;
     return f;
 }
-/* Rewrite strncpy (Cannot use strncpy_s as its semantic is too bothersome) */
-static inline void m_core_strncpy(char s1[], const char s2[], size_t size)
-{
-  while (size > 0) {
-    *s1 = *s2;
-    s1 ++;
-    s2 += (*s2 != 0);
-    size --;
-  }
-  // No final null char (it may not appear in case of truncation)
-}
-/* Rewrite strncat (Cannot use strncat_s as its semantic is too bothersome) */
-static inline void m_core_strncat(char s1[], const char s2[], size_t size)
-{
-  // Go to the end of s1
-  while (*s1 != 0) {
-    s1++;
-  }
-  // Copy at most size bytes of s2 in s1.
-  while (size > 0)
-  {
-    *s1 = *s2;
-    if (*s2 == 0) {
-      break;
-    }
-    s1 ++;
-    s2 ++;
-    size --;
-  }
-  // Always a final null char.
-  *s1 = 0;
-}
+
+/* Wrapper around strncpy */
+#define m_core_strncpy(s1, alloc, s2, size) strncpy_s(s1, alloc, s2, size)
+
+/* Wrapper around strncat */
+#define m_core_strncat(s1, alloc, s2, size) strncat_s(s1, alloc, s2, size)
+
 /* Wrapper around fscanf_s */
 #define m_core_fscanf(...) fscanf_s(__VA_ARGS__)
-
 /* Macro to be used in m_core_fscanf for argument associated
  * to the format %c, %s or %[
  * in order to specify the size of the argument */
@@ -1801,9 +1775,9 @@ static inline void m_core_strncat(char s1[], const char s2[], size_t size)
 /* Wrapper around fopen */
 #define m_core_fopen(...) fopen(__VA_ARGS__)
 /* Wrapper around strncpy */
-#define m_core_strncpy(...) strncpy(__VA_ARGS__)
+#define m_core_strncpy(s1, alloc, s2, size) strncpy(s1, s2, size)
 /* Wrapper around strncat */
-#define m_core_strncat(s1, s2, size) strncat(s1, s2, size)
+#define m_core_strncat(s1, alloc, s2, size) strncat(s1, s2, size)
 /* Wrapper around fscanf */
 #define m_core_fscanf(...) fscanf(__VA_ARGS__)
 

m-string.h

@@ -2035,7 +2035,7 @@ namespace m_lib {
   M_C(name, _set_str)(bounded_t s, const char str[])                          \
   {                                                                           \
     BOUNDED_STRINGI_CONTRACT(s, max_size);                                    \
-    m_core_strncpy(s->s, str, max_size);                                      \
+    m_core_strncpy(s->s, max_size+1, str, max_size);                          \
     BOUNDED_STRINGI_CONTRACT(s, max_size);                                    \
   }                                                                           \
                                                                               \
@@ -2045,7 +2045,7 @@ namespace m_lib {
     BOUNDED_STRINGI_CONTRACT(s, max_size);                                    \
     M_ASSERT(str != NULL);                                                    \
     size_t len = M_MIN(max_size, n);                                          \
-    m_core_strncpy(s->s, str, len);                                           \
+    m_core_strncpy(s->s, max_size+1, str, len);                               \
     s->s[len] = 0;                                                            \
     BOUNDED_STRINGI_CONTRACT(s, max_size);                                    \
   }                                                                           \
@@ -2095,7 +2095,7 @@ namespace m_lib {
     BOUNDED_STRINGI_CONTRACT(s, max_size);                                    \
     M_ASSERT (str != NULL);                                                   \
     M_ASSERT_INDEX (strlen(s->s), max_size+1);                                \
-    m_core_strncat(s->s, str, max_size-strlen(s->s));                         \
+    m_core_strncat(s->s, max_size+1, str, max_size-strlen(s->s));             \
   }                                                                           \
                                                                               \
   static inline void                                                          \
@@ -2256,7 +2256,7 @@ namespace m_lib {
     string_t v2;                                                              \
     string_init(v2);                                                          \
     bool ret = string_in_str(v2, f);                                          \
-    m_core_strncpy(v->s, string_get_cstr(v2), max_size);                      \
+    m_core_strncpy(v->s, max_size+1, string_get_cstr(v2), max_size);          \
     string_clear(v2);                                                         \
     return ret;                                                               \
   }                                                                           \
@@ -2269,7 +2269,7 @@ namespace m_lib {
     string_t v2;                                                              \
     string_init(v2);                                                          \
     bool ret = string_parse_str(v2, str, endptr);                             \
-    m_core_strncpy(v->s, string_get_cstr(v2), max_size);                      \
+    m_core_strncpy(v->s, max_size+1, string_get_cstr(v2), max_size);          \
     string_clear(v2);                                                         \
     return ret;                                                               \
   }                                                                           \
@@ -2291,7 +2291,7 @@ namespace m_lib {
     /* TODO: Not optimum */                                                   \
     string_init(tmp);                                                         \
     m_serial_return_code_t r = serial->m_interface->read_string(serial, tmp); \
-    m_core_strncpy(v->s, string_get_cstr(tmp), max_size);                     \
+    m_core_strncpy(v->s, max_size+1, string_get_cstr(tmp), max_size);         \
     string_clear(tmp);                                                        \
     BOUNDED_STRINGI_CONTRACT(v, max_size);                                    \
     return r;                                                                 \
@@ -2314,7 +2314,7 @@ namespace m_lib {
       inline m_bounded_string(const char lstr[])
       {
         memset(this->s, 0, N);
-        m_core_strncpy(this->s, lstr, N-1);
+        m_core_strncpy(this->s, N, lstr, N-1);
       }
     };
 }