Guard individual compatibility header prototypes.

This is to avoid redefining prototypes from the libc headers. Also,
simplify the autoconf function checks and remove some copy/paste
errors checking for 'write'.

ok wouter@

configure.ac.tpl

@@ -57,60 +57,60 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])],
 )
 CFLAGS="$save_cflags $AM_CFLAGS"
 
-AC_CHECK_FUNC(strlcpy,[AC_SEARCH_LIBS(strlcpy,, [NO_STRLCPY=],
-			  [NO_STRLCPY=yes])], [NO_STRLCPY=yes])
-AC_SUBST(NO_STRLCPY)
-AM_CONDITIONAL(NO_STRLCPY, test "x$NO_STRLCPY" = "xyes")
+AC_CHECK_FUNC(strlcpy, 
+	AM_CONDITIONAL(NO_STRLCPY, false),
+	AC_DEFINE(NO_STRLCPY)
+	AM_CONDITIONAL(NO_STRLCPY, true))
 
-AC_CHECK_FUNC(strlcat,[AC_SEARCH_LIBS(strlcat,, [NO_STRLCAT=],
-			  [NO_STRLCAT=yes])], [NO_STRLCAT=yes])
-AC_SUBST(NO_STRLCAT)
-AM_CONDITIONAL(NO_STRLCAT, test "x$NO_STRLCAT" = "xyes")
+AC_CHECK_FUNC(strlcat,
+	AM_CONDITIONAL(NO_STRLCAT, false),
+	AC_DEFINE(NO_STRLCAT)
+	AM_CONDITIONAL(NO_STRLCAT, true))
 
-AC_CHECK_FUNC(strndup,[AC_SEARCH_LIBS(strndup,, [NO_STRNDUP=],
-			  [NO_STRNDUP=yes])], [NO_STRNDUP=yes])
-AC_SUBST(NO_STRNDUP)
-AM_CONDITIONAL(NO_STRNDUP, test "x$NO_STRNDUP" = "xyes")
+AC_CHECK_FUNC(strndup,
+	AM_CONDITIONAL(NO_STRNDUP, false),
+	AC_DEFINE(NO_STRNDUP)
+	AM_CONDITIONAL(NO_STRNDUP, true))
 
-AC_CHECK_FUNC(reallocarray,[AC_SEARCH_LIBS(reallocarray,, [NO_REALLOCARRAY=],
-			  [NO_REALLOCARRAY=yes])], [NO_REALLOCARRAY=yes])
-AC_SUBST(NO_REALLOCARRAY)
-AM_CONDITIONAL(NO_REALLOCARRAY, test "x$NO_REALLOCARRAY" = "xyes")
+AC_CHECK_FUNC(reallocarray,
+	AM_CONDITIONAL(NO_REALLOCARRAY, false),
+	AC_DEFINE(NO_REALLOCARRAY)
+	AM_CONDITIONAL(NO_REALLOCARRAY, true))
 
-AC_CHECK_FUNC(timingsafe_bcmp,[AC_SEARCH_LIBS(timingsafe_bcmp,, [NO_TIMINGSAFE_BCMP=],
-			  [NO_TIMINGSAFE_BCMP=yes])], [NO_TIMINGSAFE_BCMP=yes])
-AC_SUBST(NO_TIMINGSAFE_BCMP)
-AM_CONDITIONAL(NO_TIMINGSAFE_BCMP, test "x$NO_TIMINGSAFE_BCMP" = "xyes")
+AC_CHECK_FUNC(timingsafe_bcmp,
+	AM_CONDITIONAL(NO_TIMINGSAFE_BCMP, false),
+	AC_DEFINE(NO_TIMINGSAFE_BCMP)
+	AM_CONDITIONAL(NO_TIMINGSAFE_BCMP, true))
 
-AC_CHECK_FUNC(timingsafe_memcmp,[AC_SEARCH_LIBS(timingsafe_memcmp,, [NO_TIMINGSAFE_MEMCMP=],
-			  [NO_TIMINGSAFE_MEMCMP=yes])], [NO_TIMINGSAFE_MEMCMP=yes])
-AC_SUBST(NO_TIMINGSAFE_MEMCMP)
-AM_CONDITIONAL(NO_TIMINGSAFE_MEMCMP, test "x$NO_TIMINGSAFE_MEMCMP" = "xyes")
+AC_CHECK_FUNC(timingsafe_memcmp,
+	AM_CONDITIONAL(NO_TIMINGSAFE_MEMCMP, false),
+	AC_DEFINE(NO_TIMINGSAFE_MEMCMP)
+	AM_CONDITIONAL(NO_TIMINGSAFE_MEMCMP, true))
 
-AC_CHECK_FUNC(arc4random_buf,[AC_SEARCH_LIBS(write,, [NO_ARC4RANDOM_BUF=],
-			  [NO_ARC4RANDOM_BUF=yes])], [NO_ARC4RANDOM_BUF=yes])
-AC_SUBST(NO_ARC4RANDOM_BUF)
-AM_CONDITIONAL(NO_ARC4RANDOM_BUF, test "x$NO_ARC4RANDOM_BUF" = "xyes")
+AC_CHECK_FUNC(arc4random_buf,
+	AM_CONDITIONAL(NO_ARC4RANDOM_BUF, false),
+	AC_DEFINE(NO_ARC4RANDOM_BUF)
+	AM_CONDITIONAL(NO_ARC4RANDOM_BUF, true))
 
-AC_CHECK_FUNC(getentropy,[AC_SEARCH_LIBS(write,, [NO_GETENTROPY=],
-			  [NO_GETENTROPY=yes])], [NO_GETENTROPY=yes])
-AC_SUBST(NO_GETENTROPY)
-AM_CONDITIONAL(NO_GETENTROPY, test "x$NO_GETENTROPY" = "xyes")
+AC_CHECK_FUNC(getentropy,
+	AM_CONDITIONAL(NO_GETENTROPY, false),
+	AC_DEFINE(NO_GETENTROPY)
+	AM_CONDITIONAL(NO_GETENTROPY, true))
 
-AC_CHECK_FUNC(issetugid,[AC_SEARCH_LIBS(write,, [NO_ISSETUGID=],
-			  [NO_ISSETUGID=yes])], [NO_ISSETUGID=yes])
-AC_SUBST(NO_ISSETUGID)
-AM_CONDITIONAL(NO_ISSETUGID, test "x$NO_ISSETUGID" = "xyes")
+AC_CHECK_FUNC(issetugid,
+	AM_CONDITIONAL(NO_ISSETUGID, false),
+	AC_DEFINE(NO_ISSETUGID)
+	AM_CONDITIONAL(NO_ISSETUGID, true))
 
-AC_CHECK_FUNC(strtonum,[AC_SEARCH_LIBS(write,, [NO_STRTONUM=],
-			  [NO_STRTONUM=yes])], [NO_STRTONUM=yes])
-AC_SUBST(NO_STRTONUM)
-AM_CONDITIONAL(NO_STRTONUM, test "x$NO_STRTONUM" = "xyes")
+AC_CHECK_FUNC(strtonum,
+	AM_CONDITIONAL(NO_STRTONUM, false),
+	AC_DEFINE(NO_STRTONUM)
+	AM_CONDITIONAL(NO_STRTONUM, true))
 
-AC_CHECK_FUNC(explicit_bzero,[AC_SEARCH_LIBS(write,, [NO_EXPLICIT_BZERO=],
-			  [NO_EXPLICIT_BZERO=yes])], [NO_EXPLICIT_BZERO=yes])
-AC_SUBST(NO_EXPLICIT_BZERO)
-AM_CONDITIONAL(NO_EXPLICIT_BZERO, test "x$NO_EXPLICIT_BZERO" = "xyes")
+AC_CHECK_FUNC(explicit_bzero,
+	AM_CONDITIONAL(NO_EXPLICIT_BZERO, false),
+	AC_DEFINE(NO_EXPLICIT_BZERO)
+	AM_CONDITIONAL(NO_EXPLICIT_BZERO, true))
 
 AC_CHECK_FUNC(getauxval, AC_DEFINE(HAVE_GETAUXVAL))
 

include/stdlib.h

@@ -7,10 +7,18 @@
 #include <sys/time.h>
 #include <stdint.h>
 
+#ifdef NO_ARC4RANDOM_BUF
 uint32_t arc4random(void);
 void arc4random_buf(void *_buf, size_t n);
+#endif
+
+#ifdef NO_REALLOCARRAY
 void *reallocarray(void *, size_t, size_t);
+#endif
+
+#ifdef NO_STRTONUM
 long long strtonum(const char *nptr, long long minval,
 		long long maxval, const char **errstr);
+#endif
 
 #endif

include/string.h

@@ -12,21 +12,34 @@
 #include <strings.h>
 #endif
 
+#ifdef NO_STRLCPY
 size_t strlcpy(char *dst, const char *src, size_t siz);
+#endif
 
+#ifdef NO_STRLCAT
 size_t strlcat(char *dst, const char *src, size_t siz);
+#endif
 
+#ifdef NO_STRNDUP
 char * strndup(const char *str, size_t maxlen);
-
 size_t strnlen(const char *str, size_t maxlen);
+#endif
 
+#ifdef NO_EXPLICIT_BZERO
 void explicit_bzero(void *, size_t);
+#endif
 
+#ifdef NO_TIMINGSAFE_BCMP
 int timingsafe_bcmp(const void *b1, const void *b2, size_t n);
+#endif
 
+#ifdef NO_TIMINGSAFE_MEMCMP
 int timingsafe_memcmp(const void *b1, const void *b2, size_t len);
+#endif
 
+#ifdef NO_MEMMEM
 void * memmem(const void *big, size_t big_len, const void *little,
 	size_t little_len);
+#endif
 
 #endif

include/unistd.h

@@ -3,7 +3,12 @@
 #ifndef LIBCRYPTOCOMPAT_UNISTD_H
 #define LIBCRYPTOCOMPAT_UNISTD_H
 
+#ifdef NO_GETENTROPY
 int getentropy(void *buf, size_t buflen);
+#endif
+
+#ifdef NO_ISSETUGID
 int issetugid(void);
+#endif
 
 #endif