sysdeps redesign: first part: minimize clr tests

 Remaining clr:
  emptyregex: can be safely guessed to no
  nullispointer: can't be safely guessed, but do we need the test?
  devurandom: can't be safely guessed
  malloc0: can more or less be safely guessed to no

12 files changed, 274 insertions, 198 deletions

diff --git a/Makefile b/Makefile
index 80c158b..d88e63d 100644
--- a/Makefile
+++ b/Makefile
@@ -134,8 +134,8 @@ libskarnet.so.xyzzy: $(ALL_DOBJS)
 
 .DELETE_ON_ERROR:
 
-src/include/$(package)/sysdeps.h: $(sysdeps)/sysdeps.h
-	exec cat < $< > $@
+src/include/$(package)/sysdeps.h: $(sysdeps)/sysdeps $(sysdeps)/target
+	exec tools/gen-sysdepsh.sh `cat $(sysdeps)/target` < $(sysdeps)/sysdeps > $@
 
 src/include/$(package)/uint16.h: $(sysdeps)/sysdeps src/headers/bits-header src/headers/bits-footer src/headers/bits-lendian src/headers/bits-bendian src/headers/bits-template src/headers/uint64-include src/include/$(package)/uint64.h
 	exec tools/gen-bits.sh $(sysdeps)/sysdeps 16 6 7 5 17 > $@
diff --git a/configure b/configure
index b8c76fc..a8ee590 100755
--- a/configure
+++ b/configure
@@ -58,6 +58,11 @@ echo () {
   printf %s\\n "$*"
 }
 
+echon () {
+  IFS=" "
+  printf %s "$*"
+}
+
 quote () {
   tr '\n' ' ' <<EOF | grep '^[-[:alnum:]_=,./:]* $' >/dev/null 2>&1 && { echo "$1" ; return 0 ; }
 $1
@@ -116,12 +121,27 @@ tryldflag () {
   fi
 }
 
+
+# Sysdeps determination functions
+
+iscached ()
+{
+  if test -n "$sysdepspre" && grep -qF "${1}: " "$sysdepspre" ; then
+    v=`grep -F "${1}: " "$sysdepspre" | tail -n 1 | awk '{print $2;}'`
+    echo "${1}: $v" >> "$sysdeps/sysdeps"
+    echo "  ... user-provided: $v"
+    return 0 ;
+  else
+    return 1 ;
+  fi
+}
+
 choose () {
   what="$1"
   name="$2"
-  macro="$3"
-  echo "Checking whether system has $4..."
-  shift 4
+  if iscached "$name" ; then return ; fi
+  echo "Checking whether system has $3..."
+  shift 3
   libs="$*"
   r=true
   case "$what" in
@@ -143,40 +163,122 @@ choose () {
     esac
   fi
   rm -f try$name.o try$name
-  echo "#undef ${package_macro_name}_HAS$macro" >> $sysdeps/sysdeps.h
   if $r ; then
     echo "$name: yes" >> $sysdeps/sysdeps
-    echo "#define ${package_macro_name}_HAS$macro" >> $sysdeps/sysdeps.h
     echo "  ... yes"
   else
     echo "$name: no" >> $sysdeps/sysdeps
     echo "  ... no"
   fi
-  echo >> $sysdeps/sysdeps.h
+}
+
+trybasic () {
+  $CC_AUTO $CPPFLAGS_AUTO $CPPFLAGS $CPPFLAGS_POST $CFLAGS_AUTO $CFLAGS $CFLAGS_POST -o "$tmpe" -c "$1" 2>/dev/null
+  r=$?
+  rm -f "$tmpe"
+  return $r
+}
+
+tryendianness () {
+  echo "Checking endianness..."
+  if iscached endianness ; then return ; fi
+  for i in endian.h sys/endian.h machine/endian.h ; do
+    cat > "$tmpc" <<EOF
+#include <$i>
+int a = 1 ;
+EOF
+    if trybasic "$tmpc" ; then
+      cat > "$tmpc" <<EOF
+#ifndef _BSD_SOURCE
+#define _BSD_SOURCE
+#endif
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE
+#endif
+#include <$i>
+int a = LITTLE_ENDIAN ;
+int b = BIG_ENDIAN ;
+int c = BYTE_ORDER ;
+EOF
+      trybasic "$tmpc" || exit 5
+      for j in little big pdp ; do
+        k=`echo $j | tr a-z A-Z`
+        cat > "$tmpc" <<EOF
+#ifndef _BSD_SOURCE
+#define _BSD_SOURCE
+#endif
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE
+#endif
+#include <$i>
+int a[BYTE_ORDER == ${k}_ENDIAN ? 1 : -1] ;
+EOF
+        if trybasic "$tmpc" ; then
+          echo "endianness: $j" >> "$sysdeps/sysdeps"
+          echo "  ... $j"
+          rm -f "$tmpc"
+          return
+        fi
+      done
+      rm -f "$tmpc"
+      echo "$0: error: unable to determine endianness according to $i" 1>&2
+      exit 1
+    fi
+  done
+  rm -f "$tmpc"
+  echo "$0: error: unable to determine endianness: no endian.h found" 1>&2
+  exit 1
+}
+
+trysigned () {
+  cat > "$tmpc" <<EOF
+#include <sys/types.h>
+int a[($1)-1 < 0 ? 1 : -1] ;
+EOF
+  trybasic "$tmpc"
+  r=$?
+  rm -f "$tmpc"
+  return $r
+}
+
+trysizes () {
+  t="$1" ; shift
+  for arg ; do
+    cat > "$tmpc" <<EOF
+#include <sys/types.h>
+int a[sizeof($t) == $arg ? 1 : -1] ;
+EOF
+    if trybasic "$tmpc" ; then
+      rm -f "$tmpc"
+      echo "$arg"
+      return
+    fi
+  done
+  rm -f "$tmpc"
+  echo "$0: error: unable to determine the size of $t on the target" 1>&2
+  exit 1
+}
+
+trystdtype () {
+  t="$1" ; shift
+  iscached "sizeofu$t" || { echon "sizeofu${t}: " ; trysizes "$t" "$@" ; } >> "$sysdeps/sysdeps"
 }
 
 trytypes () {
   echo "Checking size and signedness of standard types..."
-  $CC_AUTO $CPPFLAGS_AUTO $CPPFLAGS $CPPFLAGS_POST $CFLAGS_AUTO $CFLAGS $CFLAGS_POST $LDFLAGS_AUTO $LDFLAGS $LDFLAGS_POST -o output-types src/sysdeps/output-types.c
-  ./output-types >> $sysdeps/sysdeps
-  ./output-types | grep -F sizeof | while read key value ; do
-    caps=$(echo $key | sed s/:\$// | tr a-z A-Z)
-    echo "#undef ${package_macro_name}_${caps}"
-    echo "#define ${package_macro_name}_${caps} $value"
-    echo
-  done >> $sysdeps/sysdeps.h
-  ./output-types | grep -F signed | while read key value ; do
-    caps=$(echo $key | sed s/:\$// | tr a-z A-Z)
-    echo "#undef ${package_macro_name}_HASUN${caps}"
-    echo "#undef ${package_macro_name}_HAS${caps}"
-    if test $value = yes ; then
-      echo "#define ${package_macro_name}_HAS${caps}"
-    else
-      echo "#define ${package_macro_name}_HASUN${caps}"
-    fi
-    echo
-  done >> $sysdeps/sysdeps.h
-  rm -f output-types
+  trystdtype short 2 4
+  trystdtype int 4 8 2
+  trystdtype long 8 4
+  for t in size uid gid pid time dev ino ; do
+    iscached "signed$t" || { echon "signed${t}: " ; if trysigned "${t}_t" ; then echo "yes" ; else echo "no" ; fi ; } >> "$sysdeps/sysdeps"
+    iscached "sizeof$t" || { echon "sizeof${t}: " ; trysizes "${t}_t" 4 8 2 ; } >> "$sysdeps/sysdeps"
+  done  
   echo "  ... done"
 }
 
@@ -231,7 +333,7 @@ libdir='$prefix/lib/$package'
 includedir='$prefix/include'
 datadir='$prefix/etc'
 sysdepdir='$prefix/lib/$package/sysdeps'
-sysdeps=
+sysdepspre=
 shared=true
 static=true
 allpic=true
@@ -261,7 +363,7 @@ for arg ; do
     --includedir=*) includedir=${arg#*=} ;;
     --datadir=*) datadir=${arg#*=} ;;
     --sysdepdir=*) sysdepdir=${arg#*=} ;;
-    --with-sysdeps=*) sysdeps=${arg#*=} ;;
+    --with-sysdeps=*) sysdepspre=${arg#*=} ;;
     --with-include=*) var=${arg#*=} ; stripdir var ; addincpath="$addincpath -I$var" ;;
     --with-lib=*) var=${arg#*=} ; stripdir var ; addlibspath="$addlibspath -L$var" ; vpaths="$vpaths $var" ;;
     --with-dynlib=*) var=${arg#*=} ; stripdir var ; addlibdpath="$addlibdpath -L$var" ; vpathd="$vpathd $var" ;;
@@ -308,7 +410,7 @@ fi
 
 # Expand installation directories
 stripdir prefix
-for i in exec_prefix dynlibdir libdir includedir datadir sysdepdir sysdeps sproot ; do
+for i in exec_prefix dynlibdir libdir includedir datadir sysdepdir sysdepspre sproot ; do
   eval tmp=\${$i}
   eval $i=$tmp
   stripdir $i
@@ -419,22 +521,21 @@ if $shared ; then
   tryldflag LDFLAGS -Wl,--hash-style=both
 fi
 
-if test -n "$sysdeps" ; then
-  if test ! -d $sysdeps || test ! -f $sysdeps/target ; then
-    echo "$0: error: $sysdeps is not a valid sysdeps directory"
+if test -n "$sysdepspre" ; then
+  if test ! -d "$sysdepspre" || test ! -f $sysdepspre/target ; then
+    echo "$0: error: $sysdepspre is not a valid sysdeps directory"
     exit 1
   fi
-  if [ "x$target" != "x$(cat $sysdeps/target)" ] ; then
-    echo "$0: error: target $target does not match the contents of $sysdeps/target"
+  if [ "x$target" != "x$(cat $sysdepspre/target)" ] ; then
+    echo "$0: error: target $target does not match the contents of $sysdepspre/target"
     exit 1
   fi
-  echo "Using pre-computed sysdeps in $sysdeps."
-  spawn_lib=$(cat $sysdeps/spawn.lib)
-  socket_lib=$(cat $sysdeps/socket.lib)
-  sysclock_lib=$(cat $sysdeps/sysclock.lib)
-  tainnow_lib=$(cat $sysdeps/tainnow.lib)
-  timer_lib=$(cat $sysdeps/timer.lib)
-  util_lib=$(cat $sysdeps/util.lib)
+  echo "Using pre-computed sysdeps in $sysdepspre."
+  spawn_lib=$(cat $sysdepspre/spawn.lib)
+  socket_lib=$(cat $sysdepspre/socket.lib)
+  sysclock_lib=$(cat $sysdepspre/sysclock.lib)
+  timer_lib=$(cat $sysdepspre/timer.lib)
+  util_lib=$(cat $sysdepspre/util.lib)
 else
   if test -n "$cross" ; then
     echo "$0: warning: possible cross-build attempt with a native compiler" 1>&2
@@ -442,17 +543,6 @@ else
   sysdeps=sysdeps.cfg
   mkdir -p $sysdeps
   echo "$target" > $sysdeps/target
-  echo "target: $target" > $sysdeps/sysdeps
-  cat <<EOF > $sysdeps/sysdeps.h
-/* ISC license. */
-
-#ifndef SYSDEPS_H
-#define SYSDEPS_H
-
-#undef SKALIBS_TARGET
-#define SKALIBS_TARGET "$target"
-
-EOF
 
   exec 3>&1
   util_lib=
@@ -461,105 +551,68 @@ EOF
   socket_lib=`trylibs lsock 'accessible socket functions' -lsocket -lnsl` || fail "$0: unable to determine socket.lib sysdep"
   echo "$socket_lib" > $sysdeps/socket.lib
 
-  hasclock=true
-  sysclock_lib=`trylibs clockrt 'clock_gettime()' -lrt` || hasclock=false
-  tainnow_lib=$sysclock_lib
+  hasclock=yes
+  sysclock_lib=`trylibs clockrt 'clock_gettime()' -lrt` || hasclock=no
   echo "$sysclock_lib" > $sysdeps/sysclock.lib
-  echo "$tainnow_lib" > $sysdeps/tainnow.lib
-  echo "#undef ${package_macro_name}_HASCLOCKRT" >> $sysdeps/sysdeps.h
-  if $hasclock ; then
-    echo 'clockrt: yes' >> $sysdeps/sysdeps
-    echo "#define ${package_macro_name}_HASCLOCKRT" >> $sysdeps/sysdeps.h
-  else
-    echo 'clockrt: no' >> $sysdeps/sysdeps
-  fi
-  echo >> $sysdeps/sysdeps.h
-  choose cl clockmon CLOCKMON CLOCK_MONOTONIC $sysclock_lib
-  choose cl clockboot CLOCKBOOT CLOCK_BOOTTIME $sysclock_lib
+  echo "clockrt: $hasclock" >> $sysdeps/sysdeps
 
-  hasspawn=true
-  spawn_lib=`trylibs posixspawn 'posix_spawn()' -lrt` || hasspawn=false
+  choose cl clockmon CLOCK_MONOTONIC $sysclock_lib
+  choose cl clockboot CLOCK_BOOTTIME $sysclock_lib
+
+  hasspawn=yes
+  spawn_lib=`trylibs posixspawn 'posix_spawn()' -lrt` || hasspawn=no
   echo "$spawn_lib" > $sysdeps/spawn.lib
-  echo "#undef ${package_macro_name}_HASPOSIXSPAWN" >> $sysdeps/sysdeps.h
-  if $hasspawn ; then
-    echo 'posixspawn: yes' >> $sysdeps/sysdeps
-    echo "#define ${package_macro_name}_HASPOSIXSPAWN" >> $sysdeps/sysdeps.h
-  else
-    echo 'posixspawn: no' >> $sysdeps/sysdeps
-  fi
-  echo >> $sysdeps/sysdeps.h
+  echo "posixspawn: $hasspawn" >> $sysdeps/sysdeps
 
-  hastimer=true
-  timer_lib=`trylibs timer 'timer_create()' -lrt` || hastimer=false
+  hastimer=yes
+  timer_lib=`trylibs timer 'timer_create()' -lrt` || hastimer=no
   echo "$timer_lib" > $sysdeps/timer.lib
-  echo "#undef ${package_macro_name}_HASTIMER" >> $sysdeps/sysdeps.h
-  if $hastimer ; then
-    echo 'timer: yes' >> $sysdeps/sysdeps
-    echo "#define ${package_macro_name}_HASTIMER" >> $sysdeps/sysdeps.h
-  else
-    echo 'timer: no' >> $sysdeps/sysdeps
-  fi
-  echo >> $sysdeps/sysdeps.h
+  echo "timer: $hastimer" >> $sysdeps/sysdeps
   exec 3>&-
 
-  echo "Checking system endianness..."
-  $CC_AUTO $CPPFLAGS_AUTO $CPPFLAGS $CPPFLAGS_POST $CFLAGS_AUTO $CFLAGS $CFLAGS_POST $LDFLAGS_AUTO $LDFLAGS $LDFLAGS_POST -o tryendianness src/sysdeps/tryendianness.c
-  endianness=$(./tryendianness) || fail "$0: unable to determine endianness"
-  echo "endianness: $endianness" >> $sysdeps/sysdeps
-  {
-    echo "#undef ${package_macro_name}_ENDIANNESS"
-    echo "#define ${package_macro_name}_ENDIANNESS \"$endianness\""
-    echo
-  } >> $sysdeps/sysdeps.h
-  echo "  ... $endianness"
-  rm -f tryendianness
-
+  tryendianness
   trytypes
-  choose clr nullispointer NULLISPOINTER 'a pointer-typed NULL'
-  choose clr accept4 ACCEPT4 'accept4()'
-  choose c cmsgcloexec CMSGCLOEXEC 'MSG_CMSG_CLOEXEC'
-  choose clr devurandom DEVURANDOM '/dev/urandom'
-  choose cl dirfd DIRFD 'dirfd()'
-  choose cl eventfd EVENTFD 'eventfd()'
-  choose cl flock FLOCK 'flock()'
-  choose cl getpeereid GETPEEREID 'getpeereid()'
-  choose cl sopeercred SOPEERCRED 'SO_PEERCRED'
-  choose cl getpeerucred GETPEERUCRED 'getpeerucred()'
-  choose cl ipv6 IPV6 'IPv6 support' $socket_lib
-  choose clr malloc0 MALLOC0 'non-NULL malloc(0)'
-  choose c msgdontwait MSGDONTWAIT 'MSG_DONTWAIT'
-  choose c odirectory ODIRECTORY 'O_DIRECTORY'
-  choose cl openat OPENAT 'openat()'
-  choose cl linkat LINKAT 'linkat()'
-  choose cl memmem MEMMEM 'memmem()'
-  choose clr pipe2 PIPE2 'pipe2()'
-  choose clr ppoll PPOLL 'ppoll()'
-  choose cl revoke REVOKE 'revoke()'
-  choose cl sendfile SENDFILE 'sendfile()'
-  choose cl setgroups SETGROUPS 'setgroups()'
-  choose cl settimeofday SETTIMEOFDAY 'settimeofday()'
-  choose clr signalfd SIGNALFD 'signalfd()'
-  choose clr splice SPLICE 'splice()'
-  choose cl strcasestr STRCASESTR 'strcasestr()'
-  choose c strnlen STRNLEN 'strnlen()'
-  choose c uint64t UINT64T 'uint64_t'
-  choose cl futimens FUTIMENS 'futimens()'
-  choose cl futimes FUTIMES 'futimes()'
-  choose cl arc4random ARC4RANDOM 'arc4random()'
-  choose cl arc4random_addrandom ARC4RANDOM_ADDRANDOM 'arc4random_addrandom()'
-  choose clr getrandom GETRANDOM 'getrandom()'
-  choose cl itimer ITIMER 'setitimer()'
-  choose cl namespaces NAMESPACES 'namespaces'
-  choose cl nsgetparent NSGETPARENT 'NS_GET_PARENT'
-  choose cl explicit_bzero EXPLICIT_BZERO 'explicit_bzero()'
-  choose clr emptyregex EMPTYREGEX 'regcomp() accept empty regexes'
-
-  echo '#endif' >> $sysdeps/sysdeps.h
-fi
+  choose cl accept4 'accept4()'
+  choose c cmsgcloexec 'MSG_CMSG_CLOEXEC'
+  choose cl dirfd 'dirfd()'
+  choose cl eventfd 'eventfd()'
+  choose cl flock 'flock()'
+  choose cl getrandom 'getrandom()'
+  choose cl getpeereid 'getpeereid()'
+  choose cl sopeercred 'SO_PEERCRED'
+  choose cl getpeerucred 'getpeerucred()'
+  choose cl ipv6 'IPv6 support' $socket_lib
+  choose c msgdontwait 'MSG_DONTWAIT'
+  choose c odirectory 'O_DIRECTORY'
+  choose cl openat 'openat()'
+  choose cl linkat 'linkat()'
+  choose cl memmem 'memmem()'
+  choose cl pipe2 'pipe2()'
+  choose cl ppoll 'ppoll()'
+  choose cl revoke 'revoke()'
+  choose cl sendfile 'sendfile()'
+  choose cl setgroups 'setgroups()'
+  choose cl settimeofday 'settimeofday()'
+  choose cl signalfd 'signalfd()'
+  choose cl splice 'splice()'
+  choose cl strcasestr 'strcasestr()'
+  choose c strnlen 'strnlen()'
+  choose c uint64t 'uint64_t'
+  choose cl futimens 'futimens()'
+  choose cl futimes 'futimes()'
+  choose cl arc4random 'arc4random()'
+  choose cl arc4random_addrandom 'arc4random_addrandom()'
+  choose cl itimer 'setitimer()'
+  choose cl namespaces 'namespaces'
+  choose cl nsgetparent 'NS_GET_PARENT'
+  choose cl explicit_bzero 'explicit_bzero()'
+
+  choose clr emptyregex 'regcomp() accept empty regexes'
+  choose clr nullispointer 'a pointer-typed NULL'
+  choose clr devurandom '/dev/urandom'
+  choose clr malloc0 'non-NULL malloc(0)'
 
-echo "Copying $sysdeps/sysdeps.h to src/include/${package}/sysdeps.h ..."
-cat < $sysdeps/sysdeps.h > src/include/${package}/sysdeps.h
-echo "  ... done"
+fi
 
 echo "Creating config.mak..."
 cmdline=$(quote "$0")
@@ -587,7 +640,6 @@ ipv6 := ${ipv6}
 SPAWN_LIB := ${spawn_lib}
 SOCKET_LIB := ${socket_lib}
 SYSCLOCK_LIB := ${sysclock_lib}
-TAINNOW_LIB := ${tainnow_lib}
 TIMER_LIB := ${timer_lib}
 UTIL_LIB := ${util_lib}
 CC := ${CC_AUTO}
diff --git a/patch-for-solaris b/patch-for-solaris
index 4ca46ef..7e43e36 100755
--- a/patch-for-solaris
+++ b/patch-for-solaris
@@ -21,7 +21,7 @@ patchit ./tools/gen-deps.sh
 patchit ./tools/gen-types.sh
 patchit ./tools/gen-types-internal.sh
 patchit ./tools/gen-bits.sh
-patchit ./tools/gen-bits-internal.sh
+patchit ./tools/make-sysdepsh.sh
 
 echo 'SHELL := /usr/xpg4/bin/sh' > Makefile.tmp
 echo >> Makefile.tmp
diff --git a/src/librandom/random_string.c b/src/librandom/random_string.c
index f8cabc3..acdec69 100644
--- a/src/librandom/random_string.c
+++ b/src/librandom/random_string.c
@@ -16,21 +16,14 @@ void random_string (char *s, size_t n)
 #else
 #ifdef SKALIBS_HASGETRANDOM
 
-#include <skalibs/nonposix.h>
-#include <unistd.h>
-#include <sys/syscall.h>
+#include <sys/random.h>
 #include <skalibs/random.h>
 
-static int getrandom (void *buf, size_t buflen, unsigned int flags)
-{
-  return syscall(SYS_getrandom, buf, buflen, flags) ;
-}
-
 void random_string (char *s, size_t n)
 {
   while (n)
   {
-    int r = getrandom(s, n, 0) ;
+    ssize_t r = getrandom(s, n, 0) ;
     if (r >= 0)
     {
       s += r ;
diff --git a/src/sysdeps/tryaccept4.c b/src/sysdeps/tryaccept4.c
index 98a75e6..ea3baaa 100644
--- a/src/sysdeps/tryaccept4.c
+++ b/src/sysdeps/tryaccept4.c
@@ -11,6 +11,10 @@
 #define _GNU_SOURCE
 #endif
 
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE
+#endif
+
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <fcntl.h>
diff --git a/src/sysdeps/trygetrandom.c b/src/sysdeps/trygetrandom.c
index 8abe3dd..cc2426b 100644
--- a/src/sysdeps/trygetrandom.c
+++ b/src/sysdeps/trygetrandom.c
@@ -1,24 +1,10 @@
 /* ISC license. */
 
-#undef _POSIX_C_SOURCE
-#undef _XOPEN_SOURCE
-
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
-
-#include <sys/types.h>
-#include <unistd.h>
-#include <sys/syscall.h>
-
-static int getrandom (void *buf, size_t buflen, unsigned int flags)
-{
-  return syscall(SYS_getrandom, buf, buflen, flags) ;
-}
+#include <sys/random.h>
 
 int main (void)
 {
   char buf[4] ;
-  if (getrandom(buf, 4, 0) < 0) return 1 ;
+  if (getrandom(buf, 4, GRND_NONBLOCK) < 0) return 1 ;
   return 0 ;
 }
diff --git a/src/sysdeps/trypipe2.c b/src/sysdeps/trypipe2.c
index 0b8cb3c..173b815 100644
--- a/src/sysdeps/trypipe2.c
+++ b/src/sysdeps/trypipe2.c
@@ -12,6 +12,9 @@
 #ifndef _BSD_SOURCE
 #define _BSD_SOURCE
 #endif
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE
+#endif
 #ifndef _NETBSD_SOURCE
 #define _NETBSD_SOURCE
 #endif
diff --git a/src/sysdeps/tryppoll.c b/src/sysdeps/tryppoll.c
index 1502f2c..18f7615 100644
--- a/src/sysdeps/tryppoll.c
+++ b/src/sysdeps/tryppoll.c
@@ -1,9 +1,20 @@
 /* ISC license. */
 
+#undef _POSIX_C_SOURCE
+#undef _XOPEN_SOURCE
+
+#ifndef _BSD_SOURCE
+#define _BSD_SOURCE
+#endif
+
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
 
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE
+#endif
+
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <time.h>
diff --git a/src/sysdeps/trysplice.c b/src/sysdeps/trysplice.c
index 8e8bd72..969c5ea 100644
--- a/src/sysdeps/trysplice.c
+++ b/src/sysdeps/trysplice.c
@@ -1,29 +1,22 @@
 /* ISC license. */
 
+#undef _POSIX_C_SOURCE
+#undef _XOPEN_SOURCE
+
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
 
-#include <sys/stat.h>
 #include <fcntl.h>
-#include <unistd.h>
-
-#define N 4096
+#include <sys/uio.h>
 
 int main (void)
 {
-  int p[2] ;
-  int fd ;
-  if (pipe(p) < 0) return 111 ;
-  fd = open("./src/sysdeps/trysplice.c", O_RDONLY) ;
-  if (fd < 0) return 111 ;
-
-  for (;;)
-  {
-    ssize_t r = splice(fd, 0, p[1], 0, N, 0) ;
-    if (r < 0) return 1 ;
-    if (!r) break ;
-    if (splice(p[0], 0, 1, 0, r, 0) < r) return 2 ;
-  }
+  char s[2][2] ;
+  struct iovec v[2] = { { .iov_base = s[0], .iov_len = 2 }, { .iov_base = s[1], .iov_len = 2 } } ;
+  loff_t in, out ;
+  ssize_t r = splice(0, &in, 1, &out, 4096, SPLICE_F_MOVE) ;
+  r = tee(0, 1, 4096, SPLICE_F_NONBLOCK) ;
+  r = vmsplice(0, v, 2, 0) ;
   return 0 ;
 }
diff --git a/tools/gen-bits-internal.sh b/tools/gen-bits-internal.sh
deleted file mode 100755
index 93e64ab..0000000
--- a/tools/gen-bits-internal.sh
+++ /dev/null
@@ -1,9 +0,0 @@
-#!/bin/sh -e
-
-bits="$1"
-dfmt="$2"
-ofmt="$3"
-xfmt="$4"
-bfmt="$5"
-
-exec sed -e "s/@BITS@/$bits/g; s/@DFMT@/$dfmt/g; s/@OFMT@/$ofmt/g; s/@XFMT@/$xfmt/g; s/@BFMT@/$bfmt/g;" < src/headers/bits-template
diff --git a/tools/gen-bits.sh b/tools/gen-bits.sh
index 951a7d9..01aa9b8 100755
--- a/tools/gen-bits.sh
+++ b/tools/gen-bits.sh
@@ -7,6 +7,10 @@ ofmt="$4"
 xfmt="$5"
 bfmt="$6"
 
+gen_bits() {
+  sed -e "s/@BITS@/$1/g; s/@DFMT@/$2/g; s/@OFMT@/$3/g; s/@XFMT@/$4/g; s/@BFMT@/$5/g;" < src/headers/bits-template
+}
+
 tools/gen-types-internal.sh "" "" "$bits" < src/headers/bits-header
 
 if test "$bits" = 64 ; then
@@ -33,5 +37,5 @@ else
 fi
 
 tools/gen-types-internal.sh "" "" "$bits" < src/headers/bits-${endian}endian
-tools/gen-bits-internal.sh "$bits" "$dfmt" "$ofmt" "$xfmt" "$bfmt"
+gen_bits "$bits" "$dfmt" "$ofmt" "$xfmt" "$bfmt"
 exec tools/gen-types-internal.sh "" "" "$bits" < src/headers/bits-footer
diff --git a/tools/gen-sysdepsh.sh b/tools/gen-sysdepsh.sh
new file mode 100755
index 0000000..f6194f2
--- /dev/null
+++ b/tools/gen-sysdepsh.sh
@@ -0,0 +1,39 @@
+#!/bin/sh
+
+cat <<EOF
+/* ISC license. */
+
+#ifndef SYSDEPS_H
+#define SYSDEPS_H
+
+#undef SKALIBS_TARGET
+#define SKALIBS_TARGET "$1"
+
+EOF
+
+while read k v ; do
+  k=$(echo "${k%%:}" | tr a-z A-Z)
+  if test ${k} != ${k##SIGNED} ; then
+    echo "#undef SKALIBS_HASUN$k"
+    echo "#undef SKALIBS_HAS$k"
+    if test $v = yes ; then
+      echo "#define SKALIBS_HAS$k"
+    else
+      echo "#define SKALIBS_HASUN$k"
+    fi
+  elif test ${k} != ${k##SIZEOF} ; then
+    echo "#undef SKALIBS_HAS$k"
+    echo "#define SKALIBS_HAS$k $v"
+  elif test ${k} = ENDIANNESS ; then
+    echo '#undef SKALIBS_ENDIANNESS'
+    echo "#define SKALIBS_ENDIANNESS $v"
+  else
+    echo "#undef SKALIBS_HAS$k"
+    if test $v = yes ; then
+      echo "#define SKALIBS_HAS$k"
+    fi
+  fi
+  echo
+done
+
+echo '#endif'