gh-127604: ensure -ldl is passed to the linker when dladdr1 is found (#133040)

Author: picnixz

Doc/library/faulthandler.rst

@@ -84,9 +84,9 @@ Dumping the C stack
 C Stack Compatibility
 *********************
 
-If the system does not support the C-level :manpage:`backtrace(3)`,
-:manpage:`backtrace_symbols(3)`, or :manpage:`dladdr(3)`, then C stack dumps
-will not work. An error will be printed instead of the stack.
+If the system does not support the C-level :manpage:`backtrace(3)`
+or :manpage:`dladdr1(3)`, then C stack dumps will not work.
+An error will be printed instead of the stack.
 
 Additionally, some compilers do not support :term:`CPython's <CPython>`
 implementation of C stack dumps. As a result, a different error may be printed

configure

@@ -2986,8 +2986,12 @@ AC_HEADER_DIRENT
 AC_HEADER_MAJOR
 
 # for faulthandler
-AC_CHECK_HEADERS([execinfo.h link.h dlfcn.h],
-                 [AC_CHECK_FUNCS(backtrace backtrace_symbols dladdr1)])
+AC_CHECK_HEADERS([execinfo.h link.h dlfcn.h], [
+  AC_CHECK_FUNCS([backtrace dladdr1], [
+    # dladdr1 requires -ldl
+    AS_VAR_APPEND([LDFLAGS], [" -ldl"])
+  ])
+])
 
 # bluetooth/bluetooth.h has been known to not compile with -std=c99.
 # http://permalink.gmane.org/gmane.linux.bluez.kernel/22294

configure.ac

@@ -92,9 +92,6 @@
 /* Define to 1 if you have the 'backtrace' function. */
 #undef HAVE_BACKTRACE
 
-/* Define to 1 if you have the 'backtrace_symbols' function. */
-#undef HAVE_BACKTRACE_SYMBOLS
-
 /* Define if you have the 'bind' function. */
 #undef HAVE_BIND