From 6a879eea3140c7ea44346752fd4c5758a72840c5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20G=C3=B3rny?= <mgorny@NetBSD.org>
Date: Thu, 11 Nov 2021 03:05:02 +0100
Subject: [PATCH] BuildSystem: Fix misdetection of gethostbyname_r() on NetBSD

Fix the configure script not to detect the presence of gethostbyname_r()
on NetBSD incorrectly.  NetBSD includes it as an internal libc symbol
that is not exposed in system headers and that is incompatible with
other implementations.  In order to avoid misdetecting it, perform
the symbol check only if the declaration is found in the public header
first.

ASTERISK-29817

Change-Id: Iafa359b09908251bcd299ff54be003ea129b9eda
---
 configure    | 85 +++++++++++++++++++++++++++++++++++++++++++++++-----
 configure.ac | 50 ++++++++++++++++++-------------
 2 files changed, 107 insertions(+), 28 deletions(-)

diff --git a/configure b/configure
index d701af6d49..0cb703530e 100755
--- a/configure
+++ b/configure
@@ -2877,6 +2877,52 @@ $as_echo "$ac_res" >&6; }
 
 } # ac_fn_c_check_member
 
+# ac_fn_c_check_decl LINENO SYMBOL VAR INCLUDES
+# ---------------------------------------------
+# Tests whether SYMBOL is declared in INCLUDES, setting cache variable VAR
+# accordingly.
+ac_fn_c_check_decl ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  as_decl_name=`echo $2|sed 's/ *(.*//'`
+  as_decl_use=`echo $2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'`
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $as_decl_name is declared" >&5
+$as_echo_n "checking whether $as_decl_name is declared... " >&6; }
+if eval \${$3+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+int
+main ()
+{
+#ifndef $as_decl_name
+#ifdef __cplusplus
+  (void) $as_decl_use;
+#else
+  (void) $as_decl_name;
+#endif
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  eval "$3=yes"
+else
+  eval "$3=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+eval ac_res=\$$3
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+
+} # ac_fn_c_check_decl
+
 # ac_fn_c_compute_int LINENO EXPR VAR INCLUDES
 # --------------------------------------------
 # Tries to find the compile-time value of EXPR in a program that includes
@@ -17339,8 +17385,30 @@ fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext conftest.$ac_ext
 
-# some systems already have gethostbyname_r so we don't need to build ours in main/utils.c
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing gethostbyname_r" >&5
+# NetBSD libc ships with an internal-only incompatible symbol gethostbyname_r
+ac_fn_c_check_decl "$LINENO" "gethostbyname_r" "ac_cv_have_decl_gethostbyname_r" "#include <stdlib.h>
+         #include <netdb.h>
+
+"
+if test "x$ac_cv_have_decl_gethostbyname_r" = xyes; then :
+  ac_have_decl=1
+else
+  ac_have_decl=0
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_DECL_GETHOSTBYNAME_R $ac_have_decl
+_ACEOF
+if test $ac_have_decl = 1; then :
+  have_gethostbyname_r_public_declaration=yes
+else
+  have_gethostbyname_r_public_declaration=no
+fi
+
+
+if test "x$have_gethostbyname_r_public_declaration" = "xyes"; then
+        # some systems already have gethostbyname_r so we don't need to build ours in main/utils.c
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing gethostbyname_r" >&5
 $as_echo_n "checking for library containing gethostbyname_r... " >&6; }
 if ${ac_cv_search_gethostbyname_r+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -17397,12 +17465,12 @@ if test "$ac_res" != no; then :
 fi
 
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for gethostbyname_r with 6 arguments" >&5
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for gethostbyname_r with 6 arguments" >&5
 $as_echo_n "checking for gethostbyname_r with 6 arguments... " >&6; }
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <stdlib.h>
-                         #include <netdb.h>
+                                 #include <netdb.h>
 int
 main ()
 {
@@ -17425,12 +17493,12 @@ fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext conftest.$ac_ext
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for gethostbyname_r with 5 arguments" >&5
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for gethostbyname_r with 5 arguments" >&5
 $as_echo_n "checking for gethostbyname_r with 5 arguments... " >&6; }
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <stdlib.h>
-	                 #include <netdb.h>
+	                         #include <netdb.h>
 int
 main ()
 {
@@ -17452,6 +17520,7 @@ $as_echo "no" >&6; }
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext conftest.$ac_ext
+fi
 
 ac_fn_c_check_header_mongrel "$LINENO" "byteswap.h" "ac_cv_header_byteswap_h" "$ac_includes_default"
 if test "x$ac_cv_header_byteswap_h" = xyes; then :
diff --git a/configure.ac b/configure.ac
index b175ef024e..371f3539e6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -945,28 +945,38 @@ AC_LINK_IFELSE(
 		AC_MSG_RESULT(no)
 )
 
-# some systems already have gethostbyname_r so we don't need to build ours in main/utils.c
-AC_SEARCH_LIBS(gethostbyname_r, [socket nsl])
-
-AC_MSG_CHECKING(for gethostbyname_r with 6 arguments)
-AC_LINK_IFELSE(
-        [AC_LANG_PROGRAM([#include <stdlib.h>
-                         #include <netdb.h>],
-                        [struct hostent *he = gethostbyname_r((const char *)NULL, (struct hostent *)NULL, (char *)NULL, (int)0, (struct hostent **)NULL, (int *)NULL);])],
-        AC_MSG_RESULT(yes)
-        AC_DEFINE([HAVE_GETHOSTBYNAME_R_6], 1, [Define to 1 if your system has gethostbyname_r with 6 arguments.]),
-        AC_MSG_RESULT(no)
+# NetBSD libc ships with an internal-only incompatible symbol gethostbyname_r
+AC_CHECK_DECLS([gethostbyname_r],
+        [have_gethostbyname_r_public_declaration=yes],
+        [have_gethostbyname_r_public_declaration=no],
+        [#include <stdlib.h>
+         #include <netdb.h>]
 )
 
-AC_MSG_CHECKING(for gethostbyname_r with 5 arguments)
-AC_LINK_IFELSE(
-        [AC_LANG_PROGRAM([#include <stdlib.h>
-	                 #include <netdb.h>],
-                        [struct hostent *he = gethostbyname_r((const char *)NULL, (struct hostent *)NULL, (char *)NULL, (int)0, (int *)NULL);])],
-        AC_MSG_RESULT(yes)
-        AC_DEFINE([HAVE_GETHOSTBYNAME_R_5], 1, [Define to 1 if your system has gethostbyname_r with 5 arguments.]),
-        AC_MSG_RESULT(no)
-)
+if test "x$have_gethostbyname_r_public_declaration" = "xyes"; then
+        # some systems already have gethostbyname_r so we don't need to build ours in main/utils.c
+        AC_SEARCH_LIBS(gethostbyname_r, [socket nsl])
+
+        AC_MSG_CHECKING(for gethostbyname_r with 6 arguments)
+        AC_LINK_IFELSE(
+                [AC_LANG_PROGRAM([#include <stdlib.h>
+                                 #include <netdb.h>],
+                                [struct hostent *he = gethostbyname_r((const char *)NULL, (struct hostent *)NULL, (char *)NULL, (int)0, (struct hostent **)NULL, (int *)NULL);])],
+                AC_MSG_RESULT(yes)
+                AC_DEFINE([HAVE_GETHOSTBYNAME_R_6], 1, [Define to 1 if your system has gethostbyname_r with 6 arguments.]),
+                AC_MSG_RESULT(no)
+        )
+
+        AC_MSG_CHECKING(for gethostbyname_r with 5 arguments)
+        AC_LINK_IFELSE(
+                [AC_LANG_PROGRAM([#include <stdlib.h>
+	                         #include <netdb.h>],
+                                [struct hostent *he = gethostbyname_r((const char *)NULL, (struct hostent *)NULL, (char *)NULL, (int)0, (int *)NULL);])],
+                AC_MSG_RESULT(yes)
+                AC_DEFINE([HAVE_GETHOSTBYNAME_R_5], 1, [Define to 1 if your system has gethostbyname_r with 5 arguments.]),
+                AC_MSG_RESULT(no)
+        )
+fi
 
 AC_CHECK_HEADER([byteswap.h], [AC_DEFINE_UNQUOTED([HAVE_BYTESWAP_H], 1, [Define to 1 if byteswap.h macros are available.])])
 
-- 
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