# HG changeset patch
# User Tassilo Philipp
# Date 1582643265 -3600
# Node ID 2f64957d6a46726dd5e690ff288135a96a2c51ce
# Parent  5ac53b2d5f1e238d801206656f3541c9ddfd7661
- fix to dynload to build with musl libc (latter has dlinfo but not RTLD_SELF, so fallback to dl_iterate_phdr if on ELF targets)

diff -r 5ac53b2d5f1e -r 2f64957d6a46 ChangeLog
--- a/ChangeLog	Sun Jan 12 11:30:40 2020 +0100
+++ b/ChangeLog	Tue Feb 25 16:07:45 2020 +0100
@@ -1,7 +1,8 @@
 This file lists bigger/noteworthy changes, only...
 
 Version 1.2 (upcoming)
-  ...
+dynload:
+  o fix to build with musl libc
 
 Version 1.1 (2020/01/11)
 dyncall:
diff -r 5ac53b2d5f1e -r 2f64957d6a46 dynload/dynload_unix.c
--- a/dynload/dynload_unix.c	Sun Jan 12 11:30:40 2020 +0100
+++ b/dynload/dynload_unix.c	Tue Feb 25 16:07:45 2020 +0100
@@ -40,13 +40,14 @@
 
 #if defined(__GLIBC__)
 /* @@@ version check glibc more precisely... dl_iterate_phdr(): glibc ver >= 2.2.4*/
-#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 3)
-#  define DL_USE_GLIBC_ITER_PHDR
-#endif
+#  if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 3)
+#    define DL_USE_GLIBC_ITER_PHDR
+#  endif
 /* to access dl_iterate_phdr(), and related w/ glibc */
 #  define _GNU_SOURCE
 #  define __USE_GNU
 #endif
+
 #include <dlfcn.h>
 
 
@@ -97,9 +98,10 @@
 /* if dlinfo() exists use it (except on glibc, where it exists since version
  * 2.3.3, but its implementation is dangerous, as no checks are done whether
  * the handle is valid, thus rendering the returned values useless) check for
- * RTLD_DI_LINKMAP which is a #define for dlinfo() on most supported targets,
- * or specifically check the OS (e.g. dlinfo() is originally from Solaris) */
-#if (defined(RTLD_DI_LINKMAP) || defined(OS_SunOS)) && !defined(DL_USE_GLIBC_ITER_PHDR)
+ * RTLD_DI_LINKMAP and RTLD_SELF, which are #defines used by dlinfo() on most
+ * supported targets, or specifically check the OS (e.g. dlinfo() is originally
+ * from Solaris) */
+#if ((defined(RTLD_DI_LINKMAP) && defined(RTLD_SELF)) || defined(OS_SunOS)) && !defined(DL_USE_GLIBC_ITER_PHDR)
 
 #include <link.h>
 
@@ -157,10 +159,11 @@
 }
 
 
-/* OpenBSD >= 3.7 has dl_iterate_phdr(), as well as glibc >= 2.2.4, however
- * skip and use on dladdr()-based guessing if if explicitly requested, e.g. by
- * ./configure */
-#elif !defined(DL_DLADDR_TO_LIBPATH) && (defined(OS_OpenBSD) || defined(DL_USE_GLIBC_ITER_PHDR))
+/* - OpenBSD >= 3.7 has dl_iterate_phdr(), as well as glibc >= 2.2.4
+   - also some libc impls (like musl) provide dlinfo(), but not RTLD_SELF (see above), however they might come
+     with dl_iterate_phdr (which comes from ELF program header iteration), so base it on that
+   - skip and use dladdr()-based guessing (see below) if explicitly requested, e.g. by ./configure */
+#elif !defined(DL_DLADDR_TO_LIBPATH) && (defined(OS_OpenBSD) || defined(DL_USE_GLIBC_ITER_PHDR) || (!defined(RTLD_SELF) && defined(__ELF__)))
 
 #include <sys/types.h>
 #include <link.h>
@@ -182,7 +185,7 @@
     /* unable to relate info->dlpi_addr directly to our dlopen handle, let's
      * do what we do on macOS above, re-dlopen the already loaded lib (just
      * increases ref count) and compare handles */
-	/* @@@ might be b/c it's the reloc addr... see below */
+    /* @@@ might be b/c it's the reloc addr... see below */
     lib = dlopen(info->dlpi_name, RTLD_LIGHTEST);
     if(lib)
       dlclose(lib);