Add sagetexecname() and all the necessary infrastructure

Signed-off-by: Laurent Bercot <ska@appnovation.com>

13 files changed, 231 insertions, 4 deletions

diff --git a/NEWS b/NEWS
index 06bc7f8..20fdf45 100644
--- a/NEWS
+++ b/NEWS
@@ -3,9 +3,12 @@ Changelog for skalibs.
 In 2.14.4.0
 -----------
 
+ - Bugfixes.
  - Documentation fixes. (This file, in particular.)
  - New functions: buffer_timed_getv, buffer_timed_putv,
    timed_read, timed_readv, timed_Write, timed_writev
+ - New sysdeps, better handling of variable sysdeps
+ - New function: sagetexecname
 
 
 In 2.14.3.0
diff --git a/configure b/configure
index e971be8..e96329f 100755
--- a/configure
+++ b/configure
@@ -51,6 +51,7 @@ Sysdeps autodetection override:
 List of mandatory sysdeps to provide by hand for cross-compiling:
   devurandom (yes|no): =yes if you have a working /dev/urandom
   posixspawnearlyreturn (yes|no): =yes if you have an old glibc or otherwise bad posix_spawn
+  procselfexe (yes|no): =yes if you have a working /proc/self/exe virtual symlink
 EOF
   exit 0
 }
@@ -187,6 +188,32 @@ choose () {
   fi
 }
 
+choosevalue () {
+  name="$1"
+  if iscached "$name" ; then return ; fi
+  if test -n "$cross" ; then
+    rm -f try$name
+    fail "$0: sysdep $name cannot be autodetected when cross-compiling. Please manually provide a value with the --with-sysdep-${name}=value... option."
+  fi
+  echo "Finding a suitable value for $2..."
+  shift 2
+  r=none
+  if $CC_AUTO $CPPFLAGS_AUTO $CPPFLAGS $CPPFLAGS_POST $CFLAGS_AUTO $CFLAGS $CFLAGS_POST -o "$tmpo" -c src/sysdeps/try$name.c 2>/dev/null \
+   && $CC_AUTO $CFLAGS_AUTO $CFLAGS $CFLAGS_POST $LDFLAGS_AUTO $LDFLAGS $LDFLAGS_POST -o try$name "$tmpo" 2>/dev/null ; then
+    while test -n "$1" ; do
+      ./try$name "$1" >/dev/null 2>&1
+      case "$?" in
+       111) fail "$0: test crashed, aborting." ;;
+       0) r="$1" ; break ;;
+      esac
+    shift
+    done
+  fi
+  rm -f try$name
+  echo "$name: $r" >> $sysdeps/sysdeps
+  echo "  ... $r"
+}
+
 trybasic () {
   $CC_AUTO $CPPFLAGS_AUTO $CPPFLAGS $CPPFLAGS_POST $CFLAGS_AUTO $CFLAGS $CFLAGS_POST -o "$tmpo" -c "$1" 2>/dev/null
 }
@@ -662,10 +689,15 @@ choose cl posixspawnsetsid 'POSIX_SPAWN_SETSID' $spawn_lib
 choose cl posixspawnsetsidnp 'POSIX_SPAWN_SETSID_NP' $spawn_lib
 choose cl posixspawnchdir 'posix_spawn_file_actions_addchdir()' $spawn_lib
 choose cl posixspawnchdirnp 'posix_spawn_file_actions_addchdir_np()' $spawn_lib
+choose cl getauxval 'getauxval()'
+choose cl kernprocpathname 'the KERN_PROC_PATHNAME sysctl'
+choose cl _nsgetexecutablepath '_NSGetExecutablePath()'
+choose cl getexecname 'getexecname()'
 
 # Here are the evil irreducible run-time sysdeps.
 choose clr devurandom '/dev/urandom'
 choose clr posixspawnearlyreturn 'posix_spawn() return early' $spawn_lib
+choosevalue procselfexe '/proc/self/exe' /proc/self/exe /proc/curproc/exe /proc/curproc/file /proc/self/path/a.out
 
 
 # Finally, produce config.mak and config.h
diff --git a/doc/libstddjb/djbunix.html b/doc/libstddjb/djbunix.html
index 39b100c..63eca54 100644
--- a/doc/libstddjb/djbunix.html
+++ b/doc/libstddjb/djbunix.html
@@ -690,6 +690,12 @@ Appends the machine's hostname to *<em>sa</em>.
 Returns 0 if it succeeds and -1 (and sets errno) if it fails.
 </p>
 
+<p>
+<code> int sagetexecname (stralloc *sa) </code> <br />
+Appends the full path of the current executable to *<em>sa</em>.
+Returns 0 if it succeeds and -1 (and sets errno) if it fails.
+</p>
+
 <h3> Temporization </h3>
 
 <p>
diff --git a/doc/upgrade.html b/doc/upgrade.html
index 147eafa..cb8aa00 100644
--- a/doc/upgrade.html
+++ b/doc/upgrade.html
@@ -22,6 +22,7 @@
  <li> New <tt>buffer_timed_getv</tt>, <tt>buffer_timed_putv</tt>,
 <tt>timed_read</tt> and <tt>timed_readv</tt>,
 <tt>timed_write</tt> and <tt>timed_writev</tt> functions. </li>
+ <li> New sysdeps, and new <tt>sagetexecname</tt> function. </li>
 </ul>
 
 <h2> in 2.14.3.0 </h2>
diff --git a/package/deps.mak b/package/deps.mak
index a69e12d..abd27b5 100644
--- a/package/deps.mak
+++ b/package/deps.mak
@@ -487,6 +487,7 @@ src/libstddjb/rmstar.o src/libstddjb/rmstar.lo: src/libstddjb/rmstar.c src/inclu
 src/libstddjb/sabasename.o src/libstddjb/sabasename.lo: src/libstddjb/sabasename.c src/include/skalibs/bytestr.h src/include/skalibs/djbunix.h src/include/skalibs/stralloc.h
 src/libstddjb/sadirname.o src/libstddjb/sadirname.lo: src/libstddjb/sadirname.c src/include/skalibs/bytestr.h src/include/skalibs/djbunix.h src/include/skalibs/stralloc.h
 src/libstddjb/sagetcwd.o src/libstddjb/sagetcwd.lo: src/libstddjb/sagetcwd.c src/include/skalibs/djbunix.h src/include/skalibs/stralloc.h
+src/libstddjb/sagetexecname.o src/libstddjb/sagetexecname.lo: src/libstddjb/sagetexecname.c src/include/skalibs/djbunix.h src/include/skalibs/nonposix.h src/include/skalibs/stralloc.h src/include/skalibs/sysdeps.h
 src/libstddjb/sagethostname.o src/libstddjb/sagethostname.lo: src/libstddjb/sagethostname.c src/include/skalibs/djbunix.h src/include/skalibs/stralloc.h
 src/libstddjb/sals.o src/libstddjb/sals.lo: src/libstddjb/sals.c src/include/skalibs/direntry.h src/include/skalibs/djbunix.h src/include/skalibs/stralloc.h
 src/libstddjb/sanitize_read.o src/libstddjb/sanitize_read.lo: src/libstddjb/sanitize_read.c src/include/skalibs/allreadwrite.h src/include/skalibs/error.h
diff --git a/src/include/skalibs/djbunix.h b/src/include/skalibs/djbunix.h
index 5bef6ec..0304ce8 100644
--- a/src/include/skalibs/djbunix.h
+++ b/src/include/skalibs/djbunix.h
@@ -82,6 +82,7 @@ extern int sadirname (stralloc *, char const *, size_t) ;
 extern int sagetcwd (stralloc *) ;
 extern int sareadlink (stralloc *, char const *) ;
 extern int sagethostname (stralloc *) ;
+extern int sagetexecname (stralloc *) ;
 
 #define slurp(sa, fd) slurpn((fd), (sa), 0)
 #define openslurpclose(sa, fn) openslurpnclose((fn), (sa), 0)
diff --git a/src/libstddjb/sagetexecname.c b/src/libstddjb/sagetexecname.c
new file mode 100644
index 0000000..d3c300b
--- /dev/null
+++ b/src/libstddjb/sagetexecname.c
@@ -0,0 +1,111 @@
+/* ISC license. */
+
+#include <skalibs/sysdeps.h>
+
+#if defined(SKALIBS_PROCSELFEXE)
+
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+int sagetexecname (stralloc *sa)
+{
+  return sareadlink(sa, SKALIBS_PROCSELFEXE) ;
+}
+
+#elif defined(SKALIBS_HASGETEXECNAME)
+
+#include <skalibs/nonposix.h>
+#include <stdlib.h>
+
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+int sagetexecname (stralloc *sa)
+{
+  return sarealpath(sa, getexecname()) ;
+}
+
+#elif defined(SKALIBS_HASKERNPROCPATHNAME)
+
+#include <skalibs/nonposix.h>
+#ifdef __NetBSD__
+#include <sys/param.h>
+#endif
+#include <limits.h>
+#include <sys/sysctl.h>
+
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+int sagetexecname (stralloc *sa)
+{
+  int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 } ;
+  char buf[PATH_MAX] ;
+  size_t len = sizeof(buf) ;
+  if (sysctl(mib, 4, buf, &len, 0, 0) == -1) return -1 ;
+  if (!stralloc_catb(sa, buf, len) || !stralloc_0(sa)) return -1 ;
+  return 0 ;
+}
+
+#elif defined(SKALIBS_HAS_NSGETEXECUTABLEPATH)
+
+#include <skalibs/nonposix.h>
+#include <sys/types.h>
+#include <stdint.h>
+#include <macho-o/dyld.h>
+
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+int sagetexecname (stralloc *sa)
+{
+  char buf[4096] ;
+  uint32_t len = sizeof(buf) ;
+  if (_NSGetExecutablePath(buf, &len) == -1) return -1 ;
+  return sarealpath(sa, buf) ;
+}
+
+#elif defined(SKALIBS_HASGETAUXVAL)
+
+#include <skalibs/nonposix.h>
+#include <sys/auxv.h>
+
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+int sagetexecname (stralloc *sa)
+{
+  unsigned long x = getauxval(AT_EXECFN) ;
+  return sarealpath(sa, (char const *)x) ;
+}
+
+#elif defined(SKALIBS_HASDLADDR)
+
+#include <skalibs/nonposix.h>
+#include <dlfcn.h>
+
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+int sagetexecname (stralloc *sa)
+{
+  Dl_info info ;
+  if (!dladdr(&main, &info)) return -1 ;
+  if (!stralloc_cats(sa, info.dli_fname) || !stralloc_0(sa)) return -1 ;
+  return 0 ;
+}
+
+#else  /* we tried */
+
+#include <errno.h>
+
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+int sagetexecname (stralloc *sa)
+{
+  errno = ENOSYS ;
+  return -1 ;
+}
+
+#endif
diff --git a/src/sysdeps/try_nsgetexecutablepath.c b/src/sysdeps/try_nsgetexecutablepath.c
new file mode 100644
index 0000000..e2599cc
--- /dev/null
+++ b/src/sysdeps/try_nsgetexecutablepath.c
@@ -0,0 +1,14 @@
+/* ISC license. */
+
+#undef _POSIX_C_SOURCE
+#undef _XOPEN_SOURCE
+
+#include <stdint.h>
+#include <mach-o/dyld.h>
+
+int main (void)
+{
+  char buf[1024] ;
+  uint32_t len = sizeof(buf) ;
+  return _NSGetExecutablePath(buf, &len) >= 0 ;
+}
diff --git a/src/sysdeps/trygetauxval.c b/src/sysdeps/trygetauxval.c
new file mode 100644
index 0000000..cbf3da4
--- /dev/null
+++ b/src/sysdeps/trygetauxval.c
@@ -0,0 +1,12 @@
+/* ISC license. */
+
+#undef _POSIX_C_SOURCE
+#undef _XOPEN_SOURCE
+
+#include <sys/auxv.h>
+
+int main (void)
+{
+  unsigned long x = getauxval(AT_EXECFN) ;
+  return 0 ;
+}
diff --git a/src/sysdeps/trygetexecname.c b/src/sysdeps/trygetexecname.c
new file mode 100644
index 0000000..ac65071
--- /dev/null
+++ b/src/sysdeps/trygetexecname.c
@@ -0,0 +1,11 @@
+/* ISC license. */
+
+#undef _POSIX_C_SOURCE
+#undef _XOPEN_SOURCE
+
+#include <stdlib.h>
+
+int main (void)
+{
+  return !!getexecname() ;
+}
diff --git a/src/sysdeps/trykernprocpathname.c b/src/sysdeps/trykernprocpathname.c
new file mode 100644
index 0000000..b8e2867
--- /dev/null
+++ b/src/sysdeps/trykernprocpathname.c
@@ -0,0 +1,18 @@
+/* ISC license. */
+
+#undef _POSIX_C_SOURCE
+#undef _XOPEN_SOURCE
+
+#include <sys/types.h>
+#ifdef __NetBSD__
+#include <sys/param.h>
+#endif
+#include <sys/sysctl.h>
+
+int main (void)
+{
+  int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 } ;
+  char buf[1024] ;
+  size_t len = sizeof(buf) ;
+  return sysctl(mib, 4, buf, &len, 0, 0) >= 0 ;
+}
diff --git a/src/sysdeps/tryprocselfexe.c b/src/sysdeps/tryprocselfexe.c
new file mode 100644
index 0000000..e8b8a88
--- /dev/null
+++ b/src/sysdeps/tryprocselfexe.c
@@ -0,0 +1,13 @@
+/* ISC license */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+
+int main (int argc, char const *const *argv)
+{
+  char buf[8192] ;
+  if (argc < 2) return 111 ;
+  ssize_t r = readlink(argv[1], buf, 8192) ;
+  return r == -1 ? errno == EIO || errno == ELOOP ? 111 : 1 : r <= 1 ;
+}
diff --git a/tools/gen-sysdepsh.sh b/tools/gen-sysdepsh.sh
index c699feb..4cb5f3d 100755
--- a/tools/gen-sysdepsh.sh
+++ b/tools/gen-sysdepsh.sh
@@ -24,13 +24,17 @@ while read k v ; do
   elif test ${k} != ${k##SIZEOF} ; then
     echo "#undef SKALIBS_$k"
     echo "#define SKALIBS_$k $v"
-  elif test ${k} = ENDIANNESS ; then
-    echo '#undef SKALIBS_ENDIANNESS'
-    echo "#define SKALIBS_ENDIANNESS \"$v\""
   else
-    echo "#undef SKALIBS_HAS$k"
     if test $v = yes ; then
+      echo "#undef SKALIBS_HAS$k"
       echo "#define SKALIBS_HAS$k"
+    elif test $v = no ; then
+      echo "#undef SKALIBS_HAS$k"
+    else
+      echo "#undef SKALIBS_$k"
+      if test $v != none ; then
+        echo "#define SKALIBS_$k \"$v\""
+      fi
     fi
   fi
   echo