Configure tests if main can be linked to from getentropy compat.

git-svn-id: file:///svn/unbound/trunk@3191 be551aaa-1e26-0410-a405-d3ace91eadb9

compat/getentropy_linux.c

@@ -72,7 +72,9 @@
 
 int	getentropy(void *buf, size_t len);
 
+#ifdef CAN_REFERENCE_MAIN
 extern int main(int, char *argv[]);
+#endif
 static int gotdata(char *buf, size_t len);
 static int getentropy_urandom(void *buf, size_t len);
 #ifdef CTL_MAXNAME
@@ -345,7 +347,9 @@ getentropy_fallback(void *buf, size_t len)
 			HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1,
 			    sigset);
 
+#ifdef CAN_REFERENCE_MAIN
 			HF(main);		/* an addr in program */
+#endif
 			HF(getentropy);	/* an addr in this library */
 			HF(printf);		/* an addr in libc */
 			p = (char *)&p;

compat/getentropy_osx.c

@@ -16,6 +16,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+#include "config.h"
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -74,7 +75,9 @@
 
 int	getentropy(void *buf, size_t len);
 
+#ifdef CAN_REFERENCE_MAIN
 extern int main(int, char *argv[]);
+#endif
 static int gotdata(char *buf, size_t len);
 static int getentropy_urandom(void *buf, size_t len);
 static int getentropy_fallback(void *buf, size_t len);
@@ -292,7 +295,9 @@ getentropy_fallback(void *buf, size_t len)
 			HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1,
 			    sigset);
 
+#ifdef CAN_REFERENCE_MAIN
 			HF(main);		/* an addr in program */
+#endif
 			HF(getentropy);	/* an addr in this library */
 			HF(printf);		/* an addr in libc */
 			p = (char *)&p;

compat/getentropy_solaris.c

@@ -65,8 +65,9 @@
 
 int	getentropy(void *buf, size_t len);
 
-/* referencing functions in other link modules is not portable with sun-cc */
-/* extern int main(int, char *argv[]); */
+#ifdef CAN_REFERENCE_MAIN
+extern int main(int, char *argv[]);
+#endif
 static int gotdata(char *buf, size_t len);
 static int getentropy_urandom(void *buf, size_t len, const char *path,
     int devfscheck);
@@ -299,8 +300,9 @@ getentropy_fallback(void *buf, size_t len)
 			HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1,
 			    sigset);
 
-			/* replaced main with log_info */
-			/*HF(main);*/		/* an addr in program */
+#ifdef CAN_REFERENCE_MAIN
+			HF(main);		/* an addr in program */
+#endif
 			HF(getentropy);	/* an addr in this library */
 			HF(printf);		/* an addr in libc */
 			p = (char *)&p;

config.h.in

@@ -1,5 +1,8 @@
 /* config.h.in.  Generated from configure.ac by autoheader.  */
 
+/* define if a library can reference the 'main' symbol */
+#undef CAN_REFERENCE_MAIN
+
 /* Directory to chroot to */
 #undef CHROOT_DIR
 
@@ -341,7 +344,7 @@
 /* Define to 1 if you have the `strptime' function. */
 #undef HAVE_STRPTIME
 
-/* Define to 1 if `ipi_spec_dst' is a member of `struct in_pktinfo'. */
+/* Define to 1 if `ipi_spec_dst' is member of `struct in_pktinfo'. */
 #undef HAVE_STRUCT_IN_PKTINFO_IPI_SPEC_DST
 
 /* Define if you have Swig libraries and header files. */
@@ -475,9 +478,6 @@
 /* Define to the one symbol short name of this package. */
 #undef PACKAGE_TARNAME
 
-/* Define to the home page for this package. */
-#undef PACKAGE_URL
-
 /* Define to the version of this package. */
 #undef PACKAGE_VERSION
 
@@ -586,11 +586,6 @@
    `char[]'. */
 #undef YYTEXT_POINTER
 
-/* Enable large inode numbers on Mac OS X 10.5.  */
-#ifndef _DARWIN_USE_64_BIT_INODE
-# define _DARWIN_USE_64_BIT_INODE 1
-#endif
-
 /* Number of bits in a file offset, on hosts where this is settable. */
 #undef _FILE_OFFSET_BITS
 

configure.ac

@@ -1021,6 +1021,39 @@ if test "$USE_NSS" = "no"; then
 				AC_SEARCH_LIBS([clock_gettime], [rt])
 			;;
 			esac
+			# generate libtool to test if linking main
+			# from a dynamic library works.
+			LT_OUTPUT
+			AC_MSG_CHECKING([if dynamic lib can refer to main])
+			cat >tmp.$$.def <<EOF
+myfunc
+EOF
+			cat >tmp.$$.c <<EOF
+int myfunc(void);
+extern int main(int, char *argv[]);
+int myfunc(void)
+{
+	return ((int)main) + 1;
+}
+EOF
+			mylibtool=./libtool
+			mylibdir=/usr/local/lib
+			myok=yes
+			$mylibtool --quiet --tag=CC --mode=compile $CC $CFLAGS -o tmp.$$.lo -c tmp.$$.c >/dev/null 2>&1
+			if test $? = 0; then myok=yes; else myok=no; fi
+			if test "$myok" = "yes"; then
+			$mylibtool --quiet --tag=CC --mode=link $CC $CFLAGS -version-info 1:0:0 -no-undefined -export-symbols tmp.$$.def -o libtmp$$.la tmp.$$.lo $LDFLAGS -rpath $mylibdir $LIBS >/dev/null 2>&1
+				if test $? = 0; then myok=yes; else myok=no; fi
+			fi
+			if test "$myok" = "yes"; then
+				AC_MSG_RESULT(yes)
+				AC_DEFINE(CAN_REFERENCE_MAIN, [1], [define if a library can reference the 'main' symbol])
+			else
+				AC_MSG_RESULT(no)
+			fi
+			$mylibtool --quiet --mode=clean rm -rf libtmp$$.la tmp.$$.lo
+			rm -f tmp.$$.def tmp.$$.c libtmp$$.la tmp.$$.lo tmp.$$.o
+
 		    fi
 		])
 	fi

doc/Changelog

@@ -1,3 +1,6 @@
+13 July 2014: Wouter
+	- Configure tests if main can be linked to from getentropy compat.
+
 12 July 2014: Wouter
 	- Fix getentropy compat code, function refs were not portable.
 	- Fix to check openssl version number only for OpenSSL.