start on makefile and fixing warnings and errors

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

41 files changed, 364 insertions, 163 deletions

diff --git a/.gitignore b/.gitignore
index e7bb01b..9a4936c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -18,4 +18,5 @@ obj/
 *.pdf
 *.dvi
 *.ps
+/config.mk
 
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..19cba87
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,112 @@
+# 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/>.
+
+
+
+
+# Flags required at compilation of a libc, specifying that unhosted C is used.
+CCFLAGS_UNHOSTED = -nostdinc -ffreestanding
+
+# Preprocessor flags defined by slibc that are required to build the slibc.
+CCFLAGS_SLIBC_DEFS = -D_SLIBC_SOURCE=1 -D_GNU_SOURCE=1 -D_BSD_SOURCE=1 -D_SLIBC_SUPPRESS_WARNINGS=1 \
+                     -D_POSIX_C_SOURCE=999999L -D_XOPEN_SOURCE=9999
+
+# Flag that specifies which C dialect the library is written.
+CCFLAGS_CSTD = -std=gnu11
+
+# Flags that specify where the system header files (that would in this case
+# be this library's header files) are located.
+CCFLAGS_INCLUDES = -Iinclude
+
+# Optimisation flags.
+CCFLAGS_OPTIIMISE = -Og -g
+
+# Warning flags.
+CCFLAGS_WARNINGS = -Wall -Wextra -Wdouble-promotion -Wformat=2 -Winit-self -Wmissing-include-dirs \
+                   -Wtrampolines -Wfloat-equal -Wshadow -Wmissing-prototypes -Wmissing-declarations \
+                   -Wredundant-decls -Wnested-externs -Winline -Wno-variadic-macros -Wsign-conversion \
+                   -Wswitch-default -Wconversion -Wsync-nand -Wunsafe-loop-optimizations -Wcast-align \
+                   -Wstrict-overflow -Wdeclaration-after-statement -Wundef -Wbad-function-cast \
+                   -Wcast-qual -Wwrite-strings -Wlogical-op -Waggregate-return -Wstrict-prototypes \
+                   -Wold-style-definition -Wpacked -Wvector-operation-performance \
+                   -Wunsuffixed-float-constants -Wsuggest-attribute=const -Wsuggest-attribute=noreturn \
+                   -Wsuggest-attribute=pure -Wsuggest-attribute=format -Wnormalized=nfkc
+# -pedantic is excluded.
+
+
+# All flags used required when compiling the library.
+CCFLAGS_COMMON = $(CCFLAGS_UNHOSTED) $(CCFLAGS_SLIBC_DEFS) $(CCFLAGS_CSTD) $(CCFLAGS_INCLUDES) \
+                 $(CCFLAGS_OPTIIMISE) $(CCFLAGS_WARNINGS)
+CCFLAGS_COMMON += $(CPPFLAGS) $(CFLAGS)
+CCFLAGS_STATIC = $(CCFLAGS_COMMON)
+CCFLAGS_SHARED = $(CCFLAGS_COMMON) -fPIC -DSHARED
+
+# Flags required when genering header file dependency list.
+MMFLAGS = $(CCFLAGS_COMMON) -MG
+
+
+# Object files to build.
+OBJECTS = $(shell find src | grep '\.c$$' | sed -e 's:^src/:obj/:' -e 's:\.c$$:\.o:')
+
+
+
+# You may add config.mk to the topmost directory
+# to change any configurations above.
+-include config.mk
+
+# The default rule.
+.PHONY: default
+default: all
+
+# Include list of file dependencies for object files.
+include obj/deps.mk
+
+
+
+
+# Build everything.
+.PHONY: all
+all: $(OBJECTS)
+	@echo $^
+
+
+# Build object file.
+obj/%.o:
+	@mkdir -p $$(dirname $@)
+	$(CC) -c -o $@ src/$*.c $(CCFLAGS_SHARED)
+
+
+
+
+
+# Generate list of file dependencies for object files.
+obj/deps.mk: Makefile
+	@mkdir -p obj
+	find src | grep '\.c$$' | xargs $(CC) -MM $(MMFLAGS) > $@
+	sed -i 's#^[^ :]*\.o: src\([^ ]*\)/[^ /]*\.c#obj\1/&#' $@
+
+
+
+# Clean generated files.
+.PHONY: clean
+clean:
+	-rm -rf obj bin
+
+# Remove all files that are not part of the source.
+.PHONY: distclean
+distclean: clean
+	-rm -f config.mk
+
diff --git a/include/assert.h b/include/assert.h
index 6315ae1..838a9bf 100644
--- a/include/assert.h
+++ b/include/assert.h
@@ -56,7 +56,7 @@
 #define static_assert _Static_assert
 
 
-#ifndef __PORTABLE
+#if (defined(_SLIBC_SOURCE) || defined(_GNU_SOURCE)) && !defined(__PORTABLE)
 /**
  * Unless `NDEBUG` is defined, print an error message
  * and abort the process, if `errnum` is non-zero.
@@ -65,15 +65,15 @@
  * 
  * `assert_perror` is a GNU extension.
  */
-#if defined(_SLIBC_SOURCE) || defined(_GNU_SOURCE)
-#ifdef assert_perror
-# undef assert_perror
-#endif
-#ifdef NDEBUG
-# define assert_perror(errnum)  ((void)0)
-#else
-# define assert_perror(errnum)  \
+# ifdef assert_perror
+#  undef assert_perror
+# endif
+# ifdef NDEBUG
+#  define assert_perror(errnum)  ((void)0)
+# else
+#  define assert_perror(errnum)  \
   ((void)((errnum == 0) ? 0 : (__assert_fail(NULL, errnum, __FILE__, __LINE__, __func__), 0)))
+# endif
 #endif
 
 
@@ -89,7 +89,6 @@
  */
 void __assert_fail(const char*, int, const char*, int, const char*)
   __noreturn __GCC_ONLY(__attribute__((nonnull(3, 4, 5))));
-#endif
 
 
 
diff --git a/include/bits/types.h b/include/bits/types.h
index e594e44..7a2244e 100644
--- a/include/bits/types.h
+++ b/include/bits/types.h
@@ -32,7 +32,7 @@
 #ifndef __MAX_OF
 # define  __MAX_OF(type)  \
   (((type)1) << sizeof(type))
-#define
+#endif
 
 
 /**
diff --git a/include/ctype.h b/include/ctype.h
index f01ad57..f98705d 100644
--- a/include/ctype.h
+++ b/include/ctype.h
@@ -35,7 +35,8 @@
  * @return     Whether the character is in
  *             ['0', '9'], ['A', 'Z'], or ['a', 'z'].
  */
-int (isalnum)(int);  /* [0x30, 0x39], [0x41, 0x5A], [0x61, 0x7A] */
+int (isalnum)(int)  /* [0x30, 0x39], [0x41, 0x5A], [0x61, 0x7A] */
+  __GCC_ONLY(__attribute__((const)));
 #if defined (__GNUC__)
 # define isalnum(c)  \
   ({ int __c = (c); (isalpha(__c) || isdigit(__c)); })
@@ -49,7 +50,8 @@ int (isalnum)(int);  /* [0x30, 0x39], [0x41, 0x5A], [0x61, 0x7A] */
  * @return     Whether the character is in
  *             ['A', 'Z'] or ['a', 'z'].
  */
-int (isalpha)(int);  /* [0x41, 0x5A], [0x61, 0x7A] */
+int (isalpha)(int)  /* [0x41, 0x5A], [0x61, 0x7A] */
+  __GCC_ONLY(__attribute__((const)));
 #define isalpha(c)  (islower(tolower(a)))
 
 
@@ -63,7 +65,8 @@ int (isalpha)(int);  /* [0x41, 0x5A], [0x61, 0x7A] */
  * @param   c  The character.
  * @return     Whether the character is a ' ' or a '\t'.
  */
-int (isblank)(int); /* ' ', '\t' */
+int (isblank)(int) /* ' ', '\t' */
+  __GCC_ONLY(__attribute__((const)));
 # if defined(__GNUC__)
 #  define isblank(c)  \
   ({ int __c = (c); ((__c == ' ') || (__c == '\t')); })
@@ -79,7 +82,8 @@ int (isblank)(int); /* ' ', '\t' */
  * @return     Whether the character is lower than ' ',
  *             or is 0x7F.
  */
-int (iscntrl)(int);  /* [0x00, 0x1F], 0x7F */
+int (iscntrl)(int)  /* [0x00, 0x1F], 0x7F */
+  __GCC_ONLY(__attribute__((const)));
 #if defined(__GNUC__)
 # define iscntrl(c)  \
   ({ int __c = (c); (((unsigned)__c < ' ') || (c__ == 0x7F)); })
@@ -92,7 +96,8 @@ int (iscntrl)(int);  /* [0x00, 0x1F], 0x7F */
  * @param   c  The character.
  * @return     Whether the character is in ['0', '9'].
  */
-int (isdigit)(int);  /* [0x30, 0x39] */
+int (isdigit)(int)  /* [0x30, 0x39] */
+  __GCC_ONLY(__attribute__((const)));
 #define isdigit(c)  ((unsigned)((c) - '0') < 10)
 
 
@@ -103,7 +108,8 @@ int (isdigit)(int);  /* [0x30, 0x39] */
  * @return     Whether the character is greater
  *             than ' ', but is not 0x7F.
  */
-int (isgraph)(int);  /* [0x21, 0x7E] */
+int (isgraph)(int)  /* [0x21, 0x7E] */
+  __GCC_ONLY(__attribute__((const)));
 #define isgraph(c)  ((unsigned)(c - 0x21) < 0x5E)
 
 
@@ -114,7 +120,8 @@ int (isgraph)(int);  /* [0x21, 0x7E] */
  * @param   c  The character.
  * @return     Whether the character is in ['a', 'z'].
  */
-int (islower)(int);  /* [0x61, 0x7A] */
+int (islower)(int)  /* [0x61, 0x7A] */
+  __GCC_ONLY(__attribute__((const)));
 #define islower(c)  ((unsigned)((c) - 'a') < 26)
 
 
@@ -126,7 +133,8 @@ int (islower)(int);  /* [0x61, 0x7A] */
  * @return     Whether the character is at least
  *             as great as ' ', but is not 0x7F.
  */
-int (isprint)(int);  /* [0x20, 0x7E] */
+int (isprint)(int)  /* [0x20, 0x7E] */
+  __GCC_ONLY(__attribute__((const)));
 #define isprint(c)  ((unsigned)(c - 0x20) < 0x5F)
 
 
@@ -138,7 +146,8 @@ int (isprint)(int);  /* [0x20, 0x7E] */
  * @param   c  The character.
  * @return     Whether the character is a punctuation.
  */
-int (ispunct)(int);  /* isprint && !isalnum && !isspace) */
+int (ispunct)(int)  /* isprint && !isalnum && !isspace) */
+  __GCC_ONLY(__attribute__((const)));
 #if defined (__GNUC__)
 # define ispunk(c)  \
   ({ int __c = (c); (isprint(__c) && !isalnum(__c) && !isspace(__c)); })
@@ -152,7 +161,8 @@ int (ispunct)(int);  /* isprint && !isalnum && !isspace) */
  * @return     Whether the character is a ' ', '\f',
  *             '\n', '\r', '\t', or '\v'.
  */
-int (isspace)(int);  /* 0x20, [0x09, 0x0D] */
+int (isspace)(int)  /* 0x20, [0x09, 0x0D] */
+  __GCC_ONLY(__attribute__((const)));
 #if defined (__GNUC__)
 # define isspace(c)  \
   ({ int __c = (c); ((__c == ' ') || ((unsigned)(__c - '\t') < 5)); })
@@ -166,7 +176,8 @@ int (isspace)(int);  /* 0x20, [0x09, 0x0D] */
  * @param   c  The character.
  * @return     Whether the character is in ['A', 'Z'].
  */
-int (isupper)(int);  /* [0x41, 0x5A] */
+int (isupper)(int)  /* [0x41, 0x5A] */
+  __GCC_ONLY(__attribute__((const)));
 #define isupper(c)  ((unsigned)((c) - 'A') < 26)
 
 
@@ -179,7 +190,8 @@ int (isupper)(int);  /* [0x41, 0x5A] */
  * @return     Whether the character is in
  *             ['0', '9'], ['A', 'Z'], or ['a', 'z'].
  */
-int (isxdigit)(int);  /* [0x30, 0x39], [0x41, 0x46], [0x61, 0x66] */
+int (isxdigit)(int)  /* [0x30, 0x39], [0x41, 0x46], [0x61, 0x66] */
+  __GCC_ONLY(__attribute__((const)));
 #if defined (__GNUC__)
 # define isxdigit(c)  \
   ({ int __c = (c); (isdigit(__c) && (tolower(__c) - 'a' < 6)); })
@@ -201,8 +213,9 @@ int (isxdigit)(int);  /* [0x30, 0x39], [0x41, 0x46], [0x61, 0x66] */
  *             Guaranteed to be unchanged if the
  *             character already is in lowercase.
  */
-int (tolower)(int);  /* [0x41, 0x5A] -> [0x61, 0x7A] */
-#define tolower(c)  ((c) | 0x20)
+int (tolower)(int)  /* [0x41, 0x5A] -> [0x61, 0x7A] */
+  __GCC_ONLY(__attribute__((const)));
+#define tolower(c)  ((unsigned)(c) | 0x20)
 
 /**
  * Convert a lowercase ASCII character to
@@ -218,8 +231,9 @@ int (tolower)(int);  /* [0x41, 0x5A] -> [0x61, 0x7A] */
  *             Guaranteed to be unchanged if the
  *             character already is in lowercase.
  */
-int (toupper)(int);  /* [0x61, 0x7A] -> [0x41, 0x5A] */
-#define toupper(c)  ((c) & ~0x20)
+int (toupper)(int)  /* [0x61, 0x7A] -> [0x41, 0x5A] */
+  __GCC_ONLY(__attribute__((const)));
+#define toupper(c)  ((unsigned)(c) & ~0x20)
 
 
 
@@ -229,7 +243,8 @@ int (toupper)(int);  /* [0x61, 0x7A] -> [0x41, 0x5A] */
  * @param   c  The character
  * @return  -  Whether the character is an ASCII character.
  */
-int (isascii)(int);  /* [0x00, 0x7E] */
+int (isascii)(int)  /* [0x00, 0x7E] */
+  __GCC_ONLY(__attribute__((const)));
 #define isascii(c)  ((unsigned)(c) < 0x7F)
 
 /**
@@ -242,9 +257,10 @@ int (isascii)(int);  /* [0x00, 0x7E] */
  * @param  c  The character with the 8:th bit cleared.
  */
 int (toascii)(int)
-  __warning("Using 'toascii' is, generally, unwise.");
+  __warning("Using 'toascii' is, generally, unwise.")
+  __GCC_ONLY(__attribute__((const)));
 #if defined(_SLIBC_SUPPRESS_WARNINGS)
-# define toascii(c)  ((c) & 0x7F)
+# define toascii(c)  ((unsigned)(c) & 0x7F)
 #endif
 
 /**
@@ -252,14 +268,16 @@ int (toascii)(int)
  * It is provided for backwards-compatibility with SVID.
  */
 int _tolower(int)
-  __deprecated("Use 'tolower' instead.");
+  __deprecated("Use 'tolower' instead.")
+  __GCC_ONLY(__attribute__((const)));
 
 /**
  * This function is identical to `tolower`.
  * It is provided for backwards-compatibility with SVID.
  */
 int _toupper(int)
-  __deprecated("Use 'toupper' instead.");
+  __deprecated("Use 'toupper' instead.")
+  __GCC_ONLY(__attribute__((const)));
 
 
 
diff --git a/include/err.h b/include/err.h
index 6e9b828..c4b241a 100644
--- a/include/err.h
+++ b/include/err.h
@@ -87,7 +87,7 @@ void vwarnx(const char*, va_list);
  * @param  ...     Formatting-arguments.
  */
 void err(int, const char*, ...)
-  __noreturn __GCC_ONLY(__attribute__((format(printf, 2, 3))));
+  __GCC_ONLY(__attribute__((format(printf, 2, 3)))) __noreturn;
 
 /**
  * Print an error message to stderr, followed by a
diff --git a/include/error.h b/include/error.h
index f38ee44..37d8328 100644
--- a/include/error.h
+++ b/include/error.h
@@ -26,7 +26,7 @@
 #endif
 
 
-#include <slibc/features.h>
+#include <stdarg.h>
 
 
 
@@ -140,7 +140,7 @@ extern volatile int error_one_per_line;
  * 
  * This is a GNU extension.
  */
-extern volatile void (*error_print_progname)(void);
+extern void (*volatile error_print_progname)(void);
 
 
 
diff --git a/include/stddef.h b/include/stddef.h
index 26286f5..871a618 100644
--- a/include/stddef.h
+++ b/include/stddef.h
@@ -44,7 +44,7 @@
  */
 #ifndef NULL
 # define NULL  ((void*)0)
-#define
+#endif
 
 
 /**
diff --git a/include/stdlib.h b/include/stdlib.h
index 3151947..c02e094 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -39,7 +39,7 @@
  */
 #ifndef NULL
 # define NULL  ((void*)0)
-#define
+#endif
 
 
 
diff --git a/include/string.h b/include/string.h
index c43b41d..fe1b930 100644
--- a/include/string.h
+++ b/include/string.h
@@ -22,6 +22,14 @@
 
 
 
+/**
+ * `NULL`'s canonical header is <stddef.h>
+ */
+#ifndef NULL
+# define NULL  ((void*)0)
+#endif
+
+
 #define __NEED_size_t
 #define __NEED_locale_t /* TODO not defined */
 
@@ -66,11 +74,13 @@ char* strerror(int)
  *                  `LC_GLOBAL_LOCALE`, lest the behaviour is undefined.
  * @return          A description of the error.
  */
+/* TODO strerror_l
 char* strerror_l(int, locale_t)
   __GCC_ONLY(__attribute__((warn_unused_result)));
+*/
 
 
-#if !defined(__PORTABLE) && !defined(_SLIBC_SOURCE)
+#if !defined(__PORTABLE)
 /**
  * Reenterant variant of `strerror`.
  * 
@@ -125,7 +135,7 @@ char* __gnu_strerror_r(int, char*, size_t); /* GNU-specific strerror_r */
  * @return       The number of bytes before the first NUL byte.
  */
 size_t strlen(const char*)
-  __GCC_ONLY(__attribute__((nonnull, warn_unused_result)));
+  __GCC_ONLY(__attribute__((nonnull, warn_unused_result, pure)));
 
 #if (defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) || \
      defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || \
@@ -140,7 +150,7 @@ size_t strlen(const char*)
  *                  `maxlen` if no NUL byte was found.
  */
 size_t strnlen(const char*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 #endif
 
 
@@ -716,7 +726,7 @@ void* memdup(const void*, size_t)
  *                see the specifications for `a` and `b`.
  */
 int memcmp(const void*, const void*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 
 /**
  * Compare two strings alphabetically in a case sensitive manner.
@@ -727,7 +737,7 @@ int memcmp(const void*, const void*, size_t)
  *             see the specifications for `a` and `b`.
  */
 int strcmp(const char*, const char*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Compare two strings alphabetically in a case sensitive manner.
@@ -739,12 +749,12 @@ int strcmp(const char*, const char*)
  *                  see the specifications for `a` and `b`.
  */
 int strncmp(const char*, const char*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 
 #if defined(_GNU_SOURCE) && !defined(__PORTABLE)
 int strverscmp(const char*, const char*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 /* TODO document and implement strverscmp */
 #endif
 
@@ -759,7 +769,7 @@ int strverscmp(const char*, const char*)
  *                   `NULL` if none were found.
  */
 void* memchr(const void*, int, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 
 #if (defined(_GNU_SOURCE) || defined(_SLIBC_SOURCE)) && !defined(__PORTABLE)
 /**
@@ -773,7 +783,7 @@ void* memchr(const void*, int, size_t)
  * @return           Pointer to the first occurrence of `c`.
  */
 void* rawmemchr(const void*, int)
-  __GCC_ONLY(__attribute__((warn_unused_result, returns_nonnull, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, returns_nonnull, nonnull, pure)));
 #endif
 
 /**
@@ -790,7 +800,7 @@ void* rawmemchr(const void*, int)
  *                   `NULL` if none were found.
  */
 void* memrchr(const void*, int, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 
 /**
  * Find the first occurrence of a byte in a string.
@@ -806,7 +816,7 @@ void* memrchr(const void*, int, size_t)
  *                  `NULL` if none were found.
  */
 char* strchr(const char*, int)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 #if (defined(_GNU_SOURCE) || defined(_SLIBC_SOURCE)) && !defined(__PORTABLE)
 /**
@@ -824,7 +834,7 @@ char* strchr(const char*, int)
  *                  if none were found.
  */
 char* strchrnul(const char*, int)
-  __GCC_ONLY(__attribute__((warn_unused_result, returns_nonnull, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, returns_nonnull, nonnull, pure)));
 #endif
 
 /**
@@ -842,7 +852,7 @@ char* strchrnul(const char*, int)
  *                  `NULL` if none were found.
  */
 char* strrchr(const char*, int)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 
 /* TODO Add case insensitive character searching functions. */
@@ -858,7 +868,7 @@ char* strrchr(const char*, int)
  *                    substring, `NULL` if not found.
  */
 char* strstr(const char*, const char*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Finds the first occurrence of a substring.
@@ -870,7 +880,7 @@ char* strstr(const char*, const char*)
  *                    substring, `NULL` if not found.
  */
 char* strcasestr(const char*, const char*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 #if defined(_SLIBC_SOURCE) && !defined(__PORTABLE)
 /**
@@ -887,7 +897,7 @@ char* strcasestr(const char*, const char*)
  *                    substring, `NULL` if not found.
  */
 char* strnstr(const char*, const char*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Finds the first occurrence of a substring.
@@ -902,7 +912,7 @@ char* strnstr(const char*, const char*, size_t)
  *                    substring, `NULL` if not found.
  */
 char* strncasestr(const char*, const char*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Finds the first occurrence of a substring.
@@ -916,7 +926,7 @@ char* strncasestr(const char*, const char*, size_t)
  * @return            Pointer to the first occurrence of the substring.
  */
 char* rawstrstr(const char*, const char*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, returns_nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, returns_nonnull, pure)));
 
 /**
  * Finds the first occurrence of a substring.
@@ -930,7 +940,7 @@ char* rawstrstr(const char*, const char*)
  * @return            Pointer to the first occurrence of the substring.
  */
 char* rawstrcasestr(const char*, const char*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, returns_nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, returns_nonnull, pure)));
 
 /**
  * Finds the first occurrence of a substring
@@ -947,7 +957,7 @@ char* rawstrcasestr(const char*, const char*)
  *                           the substring, `NULL` if not found.
  */
 void* memcasemem(const void*, size_t, const void*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 #endif
 
 #if (defined(_GNU_SOURCE) || defined(_SLIBC_SOURCE)) && !defined(__PORTABLE)
@@ -966,7 +976,7 @@ void* memcasemem(const void*, size_t, const void*, size_t)
  *                           the substring, `NULL` if not found.
  */
 void* memmem(const void*, size_t, const void*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 #endif
 
 
@@ -983,7 +993,7 @@ void* memmem(const void*, size_t, const void*, size_t)
  * @return           The length of the substring.
  */
 size_t strspn(const char*, const char*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Returns length of the initial substring
@@ -995,7 +1005,7 @@ size_t strspn(const char*, const char*)
  * @return           The length of the substring.
  */
 size_t strcspn(const char*, const char*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * This function works like `strcspn`,
@@ -1010,7 +1020,7 @@ size_t strcspn(const char*, const char*)
  *                   `NULL` is returned if none is found.
  */
 char* stpbrk(const char*, const char*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 
 /**
@@ -1086,7 +1096,7 @@ char* strsep(char** restrict, const char* restrict)
  *                    so it must not freed or edited.
  */
 char* __gnu_basename(const char*)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 # define basename  __gnu_basename
 #endif
 
diff --git a/include/strings.h b/include/strings.h
index 2044fa6..a06a167 100644
--- a/include/strings.h
+++ b/include/strings.h
@@ -64,7 +64,7 @@ void bcopy(const void*, void*, size_t)
  */
 int bcmp(const void*, const void*, size_t)
   __deprecated("Use 'memcmp' instead.")
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 
 
 /**
@@ -78,7 +78,7 @@ int bcmp(const void*, const void*, size_t)
  *             see the specifications for `a` and `b`.
  */
 int strcasecmp(const char*, const char*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Compare two strings alphabetically in a case insensitive manner.
@@ -92,7 +92,7 @@ int strcasecmp(const char*, const char*)
  *                  see the specifications for `a` and `b`.
  */
 int strncasecmp(const char*, const char*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 
 /**
@@ -102,7 +102,7 @@ int strncasecmp(const char*, const char*, size_t)
  */
 char* index(const char*, int)
   __deprecated("Use 'strchr' instead.")
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * This function is identical to `strrchr`.
@@ -111,7 +111,7 @@ char* index(const char*, int)
  */
 char* rindex(const char*, int)
   __deprecated("Use 'strrchr' instead.")
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 
 
diff --git a/include/wchar.h b/include/wchar.h
index faf9275..12b1de9 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -23,6 +23,14 @@
 
 
 
+/**
+ * `NULL`'s canonical header is <stddef.h>
+ */
+#ifndef NULL
+# define NULL  ((void*)0)
+#endif
+
+
 #define __NEED_size_t
 #define __NEED_wchar_t
 
@@ -37,7 +45,7 @@
  *               first NUL character.
  */
 size_t wcslen(const wchar_t*)
-  __GCC_ONLY(__attribute__((nonnull, warn_unused_result)));
+  __GCC_ONLY(__attribute__((nonnull, warn_unused_result, pure)));
 
 #if (defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) || \
      defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || \
@@ -52,7 +60,7 @@ size_t wcslen(const wchar_t*)
  *                  NUL character was found.
  */
 size_t wcsnlen(const wchar_t*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 #endif
 
 
@@ -200,7 +208,7 @@ wchar_t* wcpcpy(wchar_t* restrict, const wchar_t* restrict)
  *                   one character passed the last written non-NUL
  *                   character.
  */
-wchar_t* wcsccpy(wchar_t* restrict, const wchar_t* restrict, wchat_t)
+wchar_t* wcsccpy(wchar_t* restrict, const wchar_t* restrict, wchar_t)
   __GCC_ONLY(__attribute__((nonnull)));
 
 /**
@@ -286,7 +294,7 @@ wchar_t* wcpncpy(wchar_t* restrict, const wchar_t* restrict, size_t)
  *                   one character passed the last written non-NUL
  *                   character.
  */
-wchar_t* wcscncpy(wchar_t* restrict, const wchar_t* restrict, wchat_t, size_t)
+wchar_t* wcscncpy(wchar_t* restrict, const wchar_t* restrict, wchar_t, size_t)
   __GCC_ONLY(__attribute__((nonnull)));
 
 /**
@@ -361,7 +369,7 @@ wchar_t* wcpmove(wchar_t*, const wchar_t*)
  *                   one character passed the last written non-NUL
  *                   character.
  */
-wchar_t* wcscmove(wchar_t*, const wchar_t*, wchat_t)
+wchar_t* wcscmove(wchar_t*, const wchar_t*, wchar_t)
   __GCC_ONLY(__attribute__((nonnull)));
 
 /**
@@ -446,7 +454,7 @@ wchar_t* wcpnmove(wchar_t*, const wchar_t*, size_t)
  *                   one character passed the last written non-NUL
  *                   character.
  */
-wchar_t* wcscnmove(wchar_t*, const wchar_t*, wchat_t, size_t)
+wchar_t* wcscnmove(wchar_t*, const wchar_t*, wchar_t, size_t)
   __GCC_ONLY(__attribute__((nonnull)));
 
 /**
@@ -641,7 +649,7 @@ wchar_t* wmemdup(const wchar_t*, size_t)
  *                see the specifications for `a` and `b`.
  */
 int wmemcmp(const wchar_t*, const wchar_t*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 
 /**
  * Compare two strings alphabetically in a case sensitive manner.
@@ -652,7 +660,7 @@ int wmemcmp(const wchar_t*, const wchar_t*, size_t)
  *             see the specifications for `a` and `b`.
  */
 int wcscmp(const wchar_t*, const wchar_t*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 #if (defined(_GNU_SOURCE) || defined(_SLIBC_SOURCE)) && !defined(__PORTABLE)
 /**
@@ -668,7 +676,7 @@ int wcscmp(const wchar_t*, const wchar_t*)
  *             see the specifications for `a` and `b`.
  */
 int wcscasecmp(const wchar_t*, const wchar_t*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Compare two strings alphabetically in a case sensitive manner.
@@ -682,7 +690,7 @@ int wcscasecmp(const wchar_t*, const wchar_t*)
  *                  see the specifications for `a` and `b`.
  */
 int wcsncmp(const wchar_t*, const wchar_t*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Compare two strings alphabetically in a case insensitive manner.
@@ -698,7 +706,7 @@ int wcsncmp(const wchar_t*, const wchar_t*, size_t)
  *                  see the specifications for `a` and `b`.
  */
 int wcsncasecmp(const wchar_t*, const wchar_t*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 #endif
 
 
@@ -713,7 +721,7 @@ int wcsncasecmp(const wchar_t*, const wchar_t*, size_t)
  *                   `NULL` if none were found.
  */
 wchar_t* wmemchr(const wchar_t*, wchar_t, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 
 #if defined(_SLIBC_SOURCE) && !defined(__PORTABLE)
 /**
@@ -728,7 +736,7 @@ wchar_t* wmemchr(const wchar_t*, wchar_t, size_t)
  * @return           Pointer to the first occurrence of `c`.
  */
 wchar_t* rawwmemchr(const wchar_t*, wchar_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, returns_nonnull, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, returns_nonnull, nonnull, pure)));
 
 /**
  * Find the last occurrence of a wide character in
@@ -747,7 +755,7 @@ wchar_t* rawwmemchr(const wchar_t*, wchar_t)
  *                   `NULL` if none were found.
  */
 wchar_t* wmemrchr(const wchar_t*, wchar_t, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 #endif
 
 /**
@@ -761,7 +769,7 @@ wchar_t* wmemrchr(const wchar_t*, wchar_t, size_t)
  *                  `NULL` if none were found.
  */
 wchar_t* wcschr(const wchar_t*, wchar_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 #if (defined(_GNU_SOURCE) || defined(_SLIBC_SOURCE)) && !defined(__PORTABLE)
 /**
@@ -780,7 +788,7 @@ wchar_t* wcschr(const wchar_t*, wchar_t)
  *                  if none were found.
  */
 wchar_t* wcschrnul(const wchar_t*, wchar_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, returns_nonnull, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, returns_nonnull, nonnull, pure)));
 #endif
 
 /**
@@ -798,7 +806,7 @@ wchar_t* wcschrnul(const wchar_t*, wchar_t)
  *                  `NULL` if none were found.
  */
 wchar_t* wcsrchr(const wchar_t*, wchar_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 
 /* TODO Add case insensitive character searching functions. */
@@ -808,7 +816,7 @@ wchar_t* wcsrchr(const wchar_t*, wchar_t)
  * This function is identical to `wcsstr`.
  */
 wchar_t* wcswcs(const wchar_t*, const wchar_t*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)))
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)))
   __deprecated("Use 'wcsstr' instead.");
 
 /**
@@ -821,7 +829,7 @@ wchar_t* wcswcs(const wchar_t*, const wchar_t*)
  *                    substring, `NULL` if not found.
  */
 wchar_t* wcsstr(const wchar_t*, const wchar_t*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 #if defined(_SLIBC_SOURCE) && !defined(__PORTABLE)
 /**
@@ -836,7 +844,7 @@ wchar_t* wcsstr(const wchar_t*, const wchar_t*)
  *                    substring, `NULL` if not found.
  */
 wchar_t* wcscasestr(const wchar_t*, const wchar_t*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Finds the first occurrence of a substring.
@@ -852,7 +860,7 @@ wchar_t* wcscasestr(const wchar_t*, const wchar_t*)
  *                    substring, `NULL` if not found.
  */
 wchar_t* wcsnstr(const wchar_t*, const wchar_t*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Finds the first occurrence of a substring.
@@ -867,7 +875,7 @@ wchar_t* wcsnstr(const wchar_t*, const wchar_t*, size_t)
  *                    substring, `NULL` if not found.
  */
 wchar_t* wcsncasestr(const wchar_t*, const wchar_t*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Finds the first occurrence of a substring.
@@ -881,7 +889,7 @@ wchar_t* wcsncasestr(const wchar_t*, const wchar_t*, size_t)
  * @return            Pointer to the first occurrence of the substring.
  */
 wchar_t* rawwcsstr(const wchar_t*, const wchar_t*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, returns_nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, returns_nonnull, pure)));
 
 /**
  * Finds the first occurrence of a substring.
@@ -895,7 +903,7 @@ wchar_t* rawwcsstr(const wchar_t*, const wchar_t*)
  * @return            Pointer to the first occurrence of the substring.
  */
 wchar_t* rawwcscasestr(const wchar_t*, const wchar_t*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, returns_nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, returns_nonnull, pure)));
 
 /**
  * Finds the first occurrence of a substring
@@ -911,7 +919,8 @@ wchar_t* rawwcscasestr(const wchar_t*, const wchar_t*)
  * @return                   Pointer to the first occurrence of
  *                           the substring, `NULL` if not found.
  */
-wchar_t* wmemcasemem(const wchar_t*, size_t, const wchar_t*, size_t);
+wchar_t* wmemcasemem(const wchar_t*, size_t, const wchar_t*, size_t)
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 #endif
 
 #if (defined(_GNU_SOURCE) || defined(_SLIBC_SOURCE)) && !defined(__PORTABLE)
@@ -931,7 +940,7 @@ wchar_t* wmemcasemem(const wchar_t*, size_t, const wchar_t*, size_t);
  *                           the substring, `NULL` if not found.
  */
 wchar_t* wmemmem(const wchar_t*, size_t, const wchar_t*, size_t)
-  __GCC_ONLY(__attribute__((warn_unused_result)));
+  __GCC_ONLY(__attribute__((warn_unused_result, pure)));
 #endif
 
 
@@ -948,7 +957,7 @@ wchar_t* wmemmem(const wchar_t*, size_t, const wchar_t*, size_t)
  * @return           The length of the substring.
  */
 size_t wcsspn(const wchar_t*, const wchar_t*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * Returns length of the initial substring
@@ -960,7 +969,7 @@ size_t wcsspn(const wchar_t*, const wchar_t*)
  * @return           The length of the substring.
  */
 size_t wcscspn(const wchar_t*, const wchar_t*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 /**
  * This function works like `strcspn`,
@@ -975,7 +984,7 @@ size_t wcscspn(const wchar_t*, const wchar_t*)
  *                   `NULL` is returned if none is found.
  */
 wchar_t* wcpbrk(const wchar_t*, const wchar_t*)
-  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull, pure)));
 
 
 /**
diff --git a/src/errno.c b/src/errno.c
new file mode 100644
index 0000000..80b46fe
--- /dev/null
+++ b/src/errno.c
@@ -0,0 +1,51 @@
+/**
+ * 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 <errno.h>
+
+
+
+/**
+ * This is the name that was used to invoke the program
+ * running in the current process. This is the value
+ * of `argv[0]` from the `main` function (where `argv`
+ * is the second parameter). If `argc` is zero, this
+ * variable will have the value `NULL`. This is not
+ * necessarily a proper comman name. For example,
+ * login shells are usually prefixes with a dash,
+ * for example "-bash", despite that there is no such
+ * command. Often, but not always, this will not contain
+ * directory.
+ * 
+ * This string may be edited if `program_invocation_short_name`
+ * or `argv[0]` is edited.
+ * 
+ * This is a GNU and slibc extension.
+ */
+char* program_invocation_name = NULL;
+
+/**
+ * Variant of `program_invocation_name` that is
+ * guaranteed to not include the directory.
+ * 
+ * This string may be edited if `program_invocation_name`
+ * or `argv[0]` is edited.
+ * 
+ * This is a GNU extension.
+ */
+char* program_invocation_short_name = NULL;
+
diff --git a/src/string/memccpy.c b/src/string/memccpy.c
index 85378d9..4212419 100644
--- a/src/string/memccpy.c
+++ b/src/string/memccpy.c
@@ -35,10 +35,10 @@
  */
 void* memccpy(void* restrict whither, const void* restrict whence, int c, size_t size)
 {
-  char_t* stop = memchr(whence, c, size);
-  void* r = NULL
+  char* stop = memchr(whence, c, size);
+  void* r = NULL;
   if (stop != NULL)
-    size = (size_t)(stop - whence), r = whither + size;
+    size = (size_t)(stop - (const char*)whence), r = whither + size;
   memcpy(whither, whence, size);
   return r;
 }
@@ -62,10 +62,10 @@ void* memccpy(void* restrict whither, const void* restrict whence, int c, size_t
  */
 void* memcmove(void* whither, const void* whence, int c, size_t size)
 {
-  char_t* stop = memchr(whence, c, size);
-  void* r = NULL
+  char* stop = memchr(whence, c, size);
+  void* r = NULL;
   if (stop != NULL)
-    size = (size_t)(stop - whence), r = whither + size;
+    size = (size_t)(stop - (const char*)whence), r = whither + size;
   memmove(whither, whence, size);
   return r;
 }
diff --git a/src/string/memcpy.c b/src/string/memcpy.c
index 4582544..02479cd 100644
--- a/src/string/memcpy.c
+++ b/src/string/memcpy.c
@@ -18,6 +18,9 @@
 #include <string.h>
 
 
+# pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
+
+
 
 /**
  * Copy a memory segment to another, non-overlapping, segment.
@@ -30,10 +33,11 @@
 void* memcpy(void* restrict whither, const void* restrict whence, size_t size)
 {
   /* TODO improve implementation of memcpy */
-  void* r = whither;
+  char* d = whither;
+  char* s = whence;
   while (size--)
-    *whither++ = *whence++;
-  return r;
+    *d++ = *s++;
+  return whither;
 }
 
 
diff --git a/src/string/memfrob.c b/src/string/memfrob.c
index e43496a..7ec9abd 100644
--- a/src/string/memfrob.c
+++ b/src/string/memfrob.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <string.h>
-#include <stddef.h>
 
 
 
diff --git a/src/string/strcat.c b/src/string/strcat.c
index ed10cc2..2205f39 100644
--- a/src/string/strcat.c
+++ b/src/string/strcat.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <string.h>
-#include <stddef.h>
 
 
 
diff --git a/src/string/strchr.c b/src/string/strchr.c
index 21345d4..2b49c2e 100644
--- a/src/string/strchr.c
+++ b/src/string/strchr.c
@@ -16,7 +16,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <string.h>
-#include <stddef.h>
+
+
+# pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
 
 
 
@@ -31,9 +33,10 @@
  */
 void* memchr(const void* segment, int c, size_t size)
 {
+  char* s = segment;
   while (size--)
-    if (*segment++ == c)
-      return segment - 1;
+    if (*s++ == c)
+      return s - 1;
   return NULL;
 }
 
@@ -50,9 +53,10 @@ void* memchr(const void* segment, int c, size_t size)
  */
 void* rawmemchr(const void* segment, int c)
 {
+  char* s = segment;
   for (;;)
-    if (*segment++ == c)
-      return segment - 1;
+    if (*s++ == c)
+      return s - 1;
 }
 
 
@@ -71,9 +75,10 @@ void* rawmemchr(const void* segment, int c)
  */
 void* memrchr(const void* segment, int c, size_t size)
 {
+  char* s = segment;
   while (size--)
-    if (segment[size] == c)
-      return segment + size;
+    if (s[size] == c)
+      return s + size;
   return NULL;
 }
 
diff --git a/src/string/strcmp.c b/src/string/strcmp.c
index 966bb06..f626f91 100644
--- a/src/string/strcmp.c
+++ b/src/string/strcmp.c
@@ -17,7 +17,6 @@
  */
 #include <string.h>
 #include <strings.h>
-#include <stddef.h>
 #include <inttypes.h>
 #include <ctype.h>
 
diff --git a/src/string/strcpy.c b/src/string/strcpy.c
index dfbdc75..17dd339 100644
--- a/src/string/strcpy.c
+++ b/src/string/strcpy.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <string.h>
-#include <stddef.h>
 
 
 
@@ -93,7 +92,7 @@ char* strstrcpy(char* restrict whither, const char* restrict whence, const char*
 {
   const char* stop = str == NULL ? NULL : strstr(whence, str);
   size_t n = stop == NULL ? strlen(whence) : (size_t)(stop - whence);
-  char* r = stop == NULL ? NULL ? whither + n;
+  char* r = stop == NULL ? NULL : (whither + n);
   memcpy(whither, whence, n);
   whither[n] = 0;
   return r;
diff --git a/src/string/strdup.c b/src/string/strdup.c
index c65970e..c23548b 100644
--- a/src/string/strdup.c
+++ b/src/string/strdup.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <string.h>
-#include <stddef.h>
 
 
 
diff --git a/src/string/strerror.c b/src/string/strerror.c
index 7366f63..87f3261 100644
--- a/src/string/strerror.c
+++ b/src/string/strerror.c
@@ -16,7 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <string.h>
-#include <stddef.h>
+#include <errno.h>
 
 
 
diff --git a/src/string/strfry.c b/src/string/strfry.c
index f020202..cf8d643 100644
--- a/src/string/strfry.c
+++ b/src/string/strfry.c
@@ -34,13 +34,16 @@
 char* strfry(char* anagram)
 {
   size_t i, j;
+  int r;
   char t;
   if (anagram == NULL)
     return NULL;
   for (i = strlen(anagram); --i;)
     {
-      j = (int)((double)rand() / (RAND_MAX + 1));
+      r = rand();
+      j = (int)((double)r / (RAND_MAX + 1));
       t = anagram[i], anagram[i] = anagram[j], anagram[j] = t;
     }
+  return anagram;
 }
 
diff --git a/src/string/strlen.c b/src/string/strlen.c
index 7023cc0..7a08fa0 100644
--- a/src/string/strlen.c
+++ b/src/string/strlen.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <string.h>
-#include <stddef.h>
 
 
 
diff --git a/src/string/strmove.c b/src/string/strmove.c
index 86298cf..596822a 100644
--- a/src/string/strmove.c
+++ b/src/string/strmove.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <string.h>
-#include <stddef.h>
 
 
 
@@ -97,7 +96,7 @@ char* strstrmove(char* whither, const char* whence, const char* restrict str)
 {
   const char* stop = str == NULL ? NULL : strstr(whence, str);
   size_t n = stop == NULL ? strlen(whence) : (size_t)(stop - whence);
-  char* r = stop == NULL ? NULL ? whither + n;
+  char* r = stop == NULL ? NULL : (whither + n);
   memmove(whither, whence, n);
   whither[n] = 0;
   return r;
diff --git a/src/string/strspn.c b/src/string/strspn.c
index cf82529..3facfd8 100644
--- a/src/string/strspn.c
+++ b/src/string/strspn.c
@@ -16,7 +16,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <string.h>
-#include <stddef.h>
+
+
+# pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
 
 
 
@@ -59,7 +61,7 @@ size_t strcspn(const char* string, const char* stopset)
   char c;
   const char* s = string;
   memset(set, 0, 256);
-  while ((c = *skipset++))
+  while ((c = *stopset++))
     set[(size_t)c] = 1;
   while ((c = *s++))
     if (!set[(size_t)c])
@@ -86,7 +88,7 @@ char* stpbrk(const char* string, const char* stopset)
   char c;
   const char* s = string;
   memset(set, 0, 256);
-  while ((c = *skipset++))
+  while ((c = *stopset++))
     set[(size_t)c] = 1;
   while ((c = *s++))
     if (!set[(size_t)c])
diff --git a/src/string/strstr.c b/src/string/strstr.c
index a7e490a..68cc647 100644
--- a/src/string/strstr.c
+++ b/src/string/strstr.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <string.h>
-#include <stddef.h>
 #include <inttypes.h>
 
 
diff --git a/src/string/strtok.c b/src/string/strtok.c
index 04668fc..1520431 100644
--- a/src/string/strtok.c
+++ b/src/string/strtok.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <string.h>
-#include <stddef.h>
 
 
 
@@ -102,7 +101,7 @@ char* strsep(char** restrict string, const char* restrict delimiters)
   if (r == NULL)
     return NULL;
   
-  next = stpbrk(string, delimiters);
+  next = stpbrk(r, delimiters);
   if (next != NULL)
     *next++ = 0;
   *string = next;
diff --git a/src/strings/bzero.c b/src/strings/bzero.c
index ab7a5f8..4be0948 100644
--- a/src/strings/bzero.c
+++ b/src/strings/bzero.c
@@ -23,7 +23,7 @@
 /**
  * `memset`, except calls to it cannot be removed by the compiler.
  */
-void* (volatile *__slibc_explicit_memset)(void*, int, size_t) = memset;
+void* (*volatile __slibc_explicit_memset)(void*, int, size_t) = memset;
 
 
 
diff --git a/src/wchar/wcscat.c b/src/wchar/wcscat.c
index c7b1c5e..491f9b7 100644
--- a/src/wchar/wcscat.c
+++ b/src/wchar/wcscat.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <wchar.h>
-#include <stddef.h>
 
 
 
@@ -55,7 +54,7 @@ wchar_t* wcscat(wchar_t* restrict whither, const wchar_t* restrict whence)
  */
 wchar_t* wcsncat(wchar_t* restrict whither, const wchar_t* restrict whence, size_t maxlen)
 {
-  wcsncpy(whither + wcslen(whither), whence, laxmen);
+  wcsncpy(whither + wcslen(whither), whence, maxlen);
   return whither;
 }
 
diff --git a/src/wchar/wcschr.c b/src/wchar/wcschr.c
index 493f0a7..16ecac2 100644
--- a/src/wchar/wcschr.c
+++ b/src/wchar/wcschr.c
@@ -16,7 +16,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <wchar.h>
-#include <stddef.h>
+
+
+# pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
 
 
 
diff --git a/src/wchar/wcscmp.c b/src/wchar/wcscmp.c
index ebac2df..c9d1180 100644
--- a/src/wchar/wcscmp.c
+++ b/src/wchar/wcscmp.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <wchar.h>
-#include <stddef.h>
 #include <inttypes.h>
 #include <wctype.h>
 
diff --git a/src/wchar/wcscpy.c b/src/wchar/wcscpy.c
index 7d75a98..37b8ed4 100644
--- a/src/wchar/wcscpy.c
+++ b/src/wchar/wcscpy.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <wchar.h>
-#include <stddef.h>
 
 
 
@@ -67,9 +66,9 @@ wchar_t* wcpcpy(wchar_t* restrict whither, const wchar_t* restrict whence)
  *                   one character passed the last written non-NUL
  *                   character.
  */
-wchar_t* wcsccpy(wchar_t* restrict whither, const wchar_t* restrict whence, wchat_t c)
+wchar_t* wcsccpy(wchar_t* restrict whither, const wchar_t* restrict whence, wchar_t c)
 {
-  wchar_t* r = wmemccopy(whither, whence, c, wcslen(whence) + 1);
+  wchar_t* r = wmemccpy(whither, whence, c, wcslen(whence) + 1);
   if (r)
     *r = 0;
   return r;
@@ -96,7 +95,7 @@ wchar_t* wcswcscpy(wchar_t* restrict whither, const wchar_t* restrict whence, co
 {
   const wchar_t* stop = str == NULL ? NULL : wcsstr(whence, str);
   size_t n = stop == NULL ? wcslen(whence) : (size_t)(stop - whence);
-  wchar_t* r = stop == NULL ? NULL ? whither + n;
+  wchar_t* r = stop == NULL ? NULL : (whither + n);
   wmemcpy(whither, whence, n);
   whither[n] = 0;
   return r;
@@ -176,11 +175,11 @@ wchar_t* wcpncpy(wchar_t* restrict whither, const wchar_t* restrict whence, size
  *                   one character passed the last written non-NUL
  *                   character.
  */
-wchar_t* wcscncpy(wchar_t* restrict whither, const wchar_t* restrict whence, wchat_t c, size_t maxlen)
+wchar_t* wcscncpy(wchar_t* restrict whither, const wchar_t* restrict whence, wchar_t c, size_t maxlen)
 {
-  const char* stop = wmemchr(whence, c, maxlen);
+  const wchar_t* stop = wmemchr(whence, c, maxlen);
   size_t n = stop == NULL ? wcsnlen(whence, maxlen) : (size_t)(stop - whence);
-  char* r = stop == NULL ? NULL : (whither + n);
+  wchar_t* r = stop == NULL ? NULL : (whither + n);
   wmemcpy(whither, whence, n);
   wmemset(whither, 0, maxlen - n);
   return r;
@@ -213,9 +212,9 @@ wchar_t* wcscncpy(wchar_t* restrict whither, const wchar_t* restrict whence, wch
 wchar_t* wcswcsncpy(wchar_t* restrict whither, const wchar_t* restrict whence,
 		    const wchar_t* restrict str, size_t maxlen)
 {
-  const char* stop = wcsnstr(whence, str, maxlen);
+  const wchar_t* stop = wcsnstr(whence, str, maxlen);
   size_t n = stop == NULL ? wcsnlen(whence, maxlen) : (size_t)(stop - whence);
-  char* r = stop == NULL ? NULL : (whither + n);
+  wchar_t* r = stop == NULL ? NULL : (whither + n);
   wmemcpy(whither, whence, n);
   wmemset(whither, 0, maxlen - n);
   return r;
diff --git a/src/wchar/wcsdup.c b/src/wchar/wcsdup.c
index dbbbb4c..37b57f9 100644
--- a/src/wchar/wcsdup.c
+++ b/src/wchar/wcsdup.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <wchar.h>
-#include <stddef.h>
 
 
 
diff --git a/src/wchar/wcslen.c b/src/wchar/wcslen.c
index ad81227..b4a07c6 100644
--- a/src/wchar/wcslen.c
+++ b/src/wchar/wcslen.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <wchar.h>
-#include <stddef.h>
 
 
 
diff --git a/src/wchar/wcsmove.c b/src/wchar/wcsmove.c
index c84e4ee..bf86928 100644
--- a/src/wchar/wcsmove.c
+++ b/src/wchar/wcsmove.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <wchar.h>
-#include <stddef.h>
 
 
 
@@ -69,7 +68,7 @@ wchar_t* wcpmove(wchar_t* whither, const wchar_t* whence)
  *                   one character passed the last written non-NUL
  *                   character.
  */
-wchar_t* wcscmove(wchar_t* whither, const wchar_t* whence, wchat_t c)
+wchar_t* wcscmove(wchar_t* whither, const wchar_t* whence, wchar_t c)
 {
   wchar_t* r = wmemcmove(whither, whence, c, wcslen(whence) + 1);
   if (r)
@@ -98,7 +97,7 @@ wchar_t* wcswcsmove(wchar_t* whither, const wchar_t* whence, const wchar_t* rest
 {
   const wchar_t* stop = str == NULL ? NULL : wcsstr(whence, str);
   size_t n = stop == NULL ? wcslen(whence) : (size_t)(stop - whence);
-  wchar_t* r = stop == NULL ? NULL ? whither + n;
+  wchar_t* r = stop == NULL ? NULL : (whither + n);
   wmemmove(whither, whence, n);
   whither[n] = 0;
   return r;
@@ -179,11 +178,11 @@ wchar_t* wcpnmove(wchar_t* whither, const wchar_t* whence, size_t maxlen)
  *                   one character passed the last written non-NUL
  *                   character.
  */
-wchar_t* wcscnmove(wchar_t* whither, const wchar_t* whence, wchat_t c, size_t maxlen)
+wchar_t* wcscnmove(wchar_t* whither, const wchar_t* whence, wchar_t c, size_t maxlen)
 {
-  const char* stop = wmemchr(whence, c, maxlen);
+  const wchar_t* stop = wmemchr(whence, c, maxlen);
   size_t n = stop == NULL ? wcsnlen(whence, maxlen) : (size_t)(stop - whence);
-  char* r = stop == NULL ? NULL : (whither + n);
+  wchar_t* r = stop == NULL ? NULL : (whither + n);
   wmemmove(whither, whence, n);
   wmemset(whither, 0, maxlen - n);
   return r;
@@ -215,9 +214,9 @@ wchar_t* wcscnmove(wchar_t* whither, const wchar_t* whence, wchat_t c, size_t ma
  */
 wchar_t* wcswcsnmove(wchar_t* whither, const wchar_t* whence, const wchar_t* restrict str, size_t maxlen)
 {
-  const char* stop = wcsnstr(whence, str, maxlen);
+  const wchar_t* stop = wcsnstr(whence, str, maxlen);
   size_t n = stop == NULL ? wcsnlen(whence, maxlen) : (size_t)(stop - whence);
-  char* r = stop == NULL ? NULL : (whither + n);
+  wchar_t* r = stop == NULL ? NULL : (whither + n);
   wmemmove(whither, whence, n);
   wmemset(whither, 0, maxlen - n);
   return r;
diff --git a/src/wchar/wcsspn.c b/src/wchar/wcsspn.c
index 360ab5f..d0ce908 100644
--- a/src/wchar/wcsspn.c
+++ b/src/wchar/wcsspn.c
@@ -16,7 +16,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <wchar.h>
-#include <stddef.h>
+
+
+# pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
 
 
 
@@ -54,7 +56,7 @@ size_t wcscspn(const wchar_t* string, const wchar_t* stopset)
   size_t end = wcslen(string);
   wchar_t* p;
   wchar_t c;
-  while ((c = *skipset++))
+  while ((c = *stopset++))
     if (p = wcsnchr(string, c, end), p != NULL)
       end = (size_t)(p - string);
   return end;
diff --git a/src/wchar/wcsstr.c b/src/wchar/wcsstr.c
index bba7d96..0ae7b71 100644
--- a/src/wchar/wcsstr.c
+++ b/src/wchar/wcsstr.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <wchar.h>
-#include <stddef.h>
 #include <inttypes.h>
 
 #define WIDE
diff --git a/src/wchar/wcstok.c b/src/wchar/wcstok.c
index 1598d07..2694dc0 100644
--- a/src/wchar/wcstok.c
+++ b/src/wchar/wcstok.c
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <wchar.h>
-#include <stddef.h>
 
 
 
@@ -80,7 +79,7 @@ wchar_t* wcssep(wchar_t** restrict string, const wchar_t* restrict delimiters)
   if (r == NULL)
     return NULL;
   
-  next = wcpbrk(string, delimiters);
+  next = wcpbrk(r, delimiters);
   if (next != NULL)
     *next++ = 0;
   *string = next;
diff --git a/src/wchar/wmemccpy.c b/src/wchar/wmemccpy.c
index fbabe0b..cde1a6a 100644
--- a/src/wchar/wmemccpy.c
+++ b/src/wchar/wmemccpy.c
@@ -38,10 +38,10 @@
 wchar_t* wmemccpy(wchar_t* restrict whither, const wchar_t* restrict whence, wchar_t c, size_t size)
 {
   wchar_t* stop = wmemchr(whence, c, size);
-  wchar_t* r = NULL
+  wchar_t* r = NULL;
   if (stop != NULL)
     size = (size_t)(stop - whence), r = whither + size;
-  memcpy(whither, whence, size);
+  wmemcpy(whither, whence, size);
   return r;
 }
 
@@ -65,10 +65,10 @@ wchar_t* wmemccpy(wchar_t* restrict whither, const wchar_t* restrict whence, wch
 wchar_t* wmemcmove(wchar_t* whither, const wchar_t* whence, wchar_t c, size_t size)
 {
   wchar_t* stop = wmemchr(whence, c, size);
-  wchar_t* r = NULL
+  wchar_t* r = NULL;
   if (stop != NULL)
     size = (size_t)(stop - whence), r = whither + size;
-  memmove(whither, whence, size);
+  wmemmove(whither, whence, size);
   return r;
 }
 
diff --git a/src/wchar/wmemset.c b/src/wchar/wmemset.c
index 2a60b45..95ec70f 100644
--- a/src/wchar/wmemset.c
+++ b/src/wchar/wmemset.c
@@ -27,7 +27,7 @@
  * @param   size     The number of wide characters in the memory segment.
  * @return           `segment` is returned.
  */
-wchar_t* wmemset(wchar_t* segment, wchar_t c, size_t size);
+wchar_t* wmemset(wchar_t* segment, wchar_t c, size_t size)
 {
   wchar_t* r = segment;
   while (size--)