configure: Add a check for the -Wl,--as-needed flag.

This fits with our general build philosophy of checking at configure
time for desired support, (rather than putting platform-specific
conditionals into our Makefiles).

1 files changed, 13 insertions, 0 deletions

diff --git a/configure b/configure
index 1d93b2e4..bab25016 100755
--- a/configure
+++ b/configure
@@ -402,6 +402,16 @@ else
     rpath_ldflags=""
 fi
 
+printf "Checking for -Wl,--as-needed... "
+if ${CC} -Wl,--as-needed -o minimal minimal.c >/dev/null 2>&1
+then
+    printf "Yes.\n"
+    as_needed_ldflags="-Wl,--as-needed"
+else
+    printf "No (nothing to worry about).\n"
+    as_needed_ldflags=""
+fi
+
 WARN_CXXFLAGS=""
 printf "Checking for available C++ compiler warning flags... "
 for flag in -Wall -Wextra -Wwrite-strings -Wswitch-enum; do
@@ -535,6 +545,9 @@ TALLOC_LDFLAGS = ${talloc_ldflags}
 # Flags needed to have linker set rpath attribute
 RPATH_LDFLAGS = ${rpath_ldflags}
 
+# Flags needed to have linker link only to necessary libraries
+AS_NEEDED_LDFLAGS = ${as_needed_ldflags}
+
 # Whether valgrind header files are available
 HAVE_VALGRIND = ${have_valgrind}