From 200a70765a503fc94b546e5a52fdd90a59eee3b3 Mon Sep 17 00:00:00 2001
From: Laurent Bercot <ska-skaware@skarnet.org>
Date: Wed, 2 Apr 2025 06:02:35 +0000
Subject:  Add sagetexecname() and all the necessary infrastructure

Signed-off-by: Laurent Bercot <ska@appnovation.com>
---
 src/include/skalibs/djbunix.h         |   1 +
 src/libstddjb/sagetexecname.c         | 111 ++++++++++++++++++++++++++++++++++
 src/sysdeps/try_nsgetexecutablepath.c |  14 +++++
 src/sysdeps/trygetauxval.c            |  12 ++++
 src/sysdeps/trygetexecname.c          |  11 ++++
 src/sysdeps/trykernprocpathname.c     |  18 ++++++
 src/sysdeps/tryprocselfexe.c          |  13 ++++
 7 files changed, 180 insertions(+)
 create mode 100644 src/libstddjb/sagetexecname.c
 create mode 100644 src/sysdeps/try_nsgetexecutablepath.c
 create mode 100644 src/sysdeps/trygetauxval.c
 create mode 100644 src/sysdeps/trygetexecname.c
 create mode 100644 src/sysdeps/trykernprocpathname.c
 create mode 100644 src/sysdeps/tryprocselfexe.c

(limited to 'src')

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 ;
+}
-- 
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