add strlen and wcslen

Signed-off-by: Mattias Andrée <maandree@operamail.com>

4 files changed, 200 insertions, 2 deletions

diff --git a/include/string.h b/include/string.h
index d30184f..560080b 100644
--- a/include/string.h
+++ b/include/string.h
@@ -25,6 +25,7 @@
 
 
 #define __NEED_size_t
+#define __NEED_wchar_t
 #define __NEED_locale_t /* TODO not defined */
 
 #include <bits/types.h>
@@ -50,7 +51,7 @@
  * @return          A description of the error.
  */
 char* strerror(int)
-  __GCC_ONLY(__attribute__((returns_nonnull)));
+  __GCC_ONLY(__attribute__((returns_nonnull, warn_unused_result)));
 
 /**
  * Return a textual representation of an error code.
@@ -68,7 +69,8 @@ char* strerror(int)
  *                  `LC_GLOBAL_LOCALE`, lest the behaviour is undefined.
  * @return          A description of the error.
  */
-char* strerror_l(int, locale_t);
+char* strerror_l(int, locale_t)
+  __GCC_ONLY(__attribute__((warn_unused_result)));
 
 
 #if !defined(_PORTABLE_SOURCE) && !defined(_SLIBC_SOURCE)
@@ -117,6 +119,33 @@ char* __gnu_strerror_r(int, char*, size_t); /* GNU-specific strerror_r */
 #endif
 
 
+/**
+ * Returns the number of bytes in a NUL-terminated
+ * string. This excludes the NUL byte.
+ * 
+ * @param   str  The string.
+ * @return       The number of bytes before the first NUL byte.
+ */
+size_t strlen(const char*)
+  __GCC_ONLY(__attribute__((nonnull, warn_unused_result)));
+
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) || \
+    defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || \
+    defined(_BSD_SOURCE)
+/**
+ * Variant of `strlen` that only inspects the
+ * beginning of s string.
+ * 
+ * @param   str     The string.
+ * @param   maxlen  The number of bytes to inspect, at most.
+ * @return          The number of bytes before, the first NUL byte.
+ *                  `maxlen` if no NUL byte was found.
+ */
+size_t strnlen(const char*, size_t)
+  __GCC_ONLY(__attribute__((warn_unused_result)));
+#endif
+
+
 
 #endif
 
diff --git a/include/wchar.h b/include/wchar.h
new file mode 100644
index 0000000..c9901d2
--- /dev/null
+++ b/include/wchar.h
@@ -0,0 +1,64 @@
+/**
+ * slibc — Yet another C library
+ * Copyright © 2015  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef _WCHAR_H
+#define _WCHAR_H
+#ifndef _PORTABLE_SOURCE /* `wchar_t` is not portable. */
+#include <slibc/version.h>
+
+
+#include <slibc/features.h>
+
+
+
+#define __NEED_size_t
+#define __NEED_wchar_t
+
+#include <bits/types.h>
+
+
+/**
+ * `wchar_t` version of `strlen`.
+ * 
+ * @param   str  The string.
+ * @return       The number of `wchar_t`:s before the
+ *               first NUL character.
+ */
+size_t wcslen(const wchar_t*)
+  __GCC_ONLY(__attribute__((nonnull, warn_unused_result)));
+
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) || \
+    defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || \
+    defined(_BSD_SOURCE)
+/**
+ * `wchar_t` version of `strnlen`.
+ * 
+ * @param   str     The string.
+ * @param   maxlen  The number of bytes to inspect, at most.
+ * @return          The number of `wchar_t`:s before the
+ *                  first NUL character. `maxlen` if no
+ *                  NUL character was found.
+ */
+size_t wcsnlen(const wchar_t*, size_t)
+  __GCC_ONLY(__attribute__((warn_unused_result)));
+#endif
+
+
+
+#endif
+#endif
+
diff --git a/src/string/strlen.c b/src/string/strlen.c
new file mode 100644
index 0000000..7023cc0
--- /dev/null
+++ b/src/string/strlen.c
@@ -0,0 +1,53 @@
+/**
+ * slibc — Yet another C library
+ * Copyright © 2015  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <string.h>
+#include <stddef.h>
+
+
+
+/**
+ * Returns the number of bytes in a NUL-terminated
+ * string. This excludes the NUL byte.
+ * 
+ * @param   str  The string.
+ * @return       The number of bytes before the first NUL byte.
+ */
+size_t strlen(const char* str)
+{
+  /* TODO optimise strlen */
+  char* s = str;
+  while (*str++);
+  return (size_t)(s - 1 - str);
+}
+
+
+/**
+ * Variant of `strlen` that only inspects the
+ * beginning of s string.
+ * 
+ * @param   str     The string.
+ * @param   maxlen  The number of bytes to inspect, at most.
+ * @return          The number of bytes before, the first NUL byte.
+ *                  `maxlen` if no NUL byte was found.
+ */
+size_t strnlen(const char* str, size_t maxlen)
+{
+  const char* end = memchr(str, 0, maxlen);
+  return end == NULL ? maxlen : (size_t)(end - str);
+}
+
diff --git a/src/wchar/wcslen.c b/src/wchar/wcslen.c
new file mode 100644
index 0000000..ad81227
--- /dev/null
+++ b/src/wchar/wcslen.c
@@ -0,0 +1,52 @@
+/**
+ * slibc — Yet another C library
+ * Copyright © 2015  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <wchar.h>
+#include <stddef.h>
+
+
+
+/**
+ * `wchar_t` version of `strlen`.
+ * 
+ * @param   str  The string.
+ * @return       The number of `wchar_t`:s before the
+ *               first NUL character.
+ */
+size_t wcslen(const wchar_t* str)
+{
+  const wchar_t* s = str;
+  while (*s++);
+  return (size_t)(s - 1 - str);
+}
+
+
+/**
+ * `wchar_t` version of `strnlen`.
+ * 
+ * @param   str     The string.
+ * @param   maxlen  The number of bytes to inspect, at most.
+ * @return          The number of `wchar_t`:s before the
+ *                  first NUL character. `maxlen` if no
+ *                  NUL character was found.
+ */
+size_t wcsnlen(const wchar_t* str, size_t maxlen)
+{
+  const wchar_t* end = wmemchr(str, 0, maxlen);
+  return end == NULL ? maxlen : (size_t)(end - str);
+}
+