automake: ask the linker to do garbage collection
By doing GC the linker removes all the symbols that are not referenced
and/or used by the final library. This results in a saving of ~100K
up-to ~600K per (stripped) binary (classic vs gallium drivers).
If interested one can ask the compiler to print the sections that are
removed using -Wl,--print-gc-sections.
v2: Check if ld supports the flag before using it.
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Acked-by: Matt Turner <mattst88@gmail.com> (v1)
diff --git a/configure.ac b/configure.ac
index 3055de6..af1b0d1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -316,6 +316,22 @@
fi
dnl
+dnl Check if linker supports garbage collection
+dnl
+save_LDFLAGS=$LDFLAGS
+LDFLAGS="$LDFLAGS -Wl,--gc-sections"
+AC_MSG_CHECKING([whether ld supports --gc-sections])
+AC_LINK_IFELSE(
+ [AC_LANG_SOURCE([static char UnusedFunc() { return 5; } int main() { return 0;}])],
+ [AC_MSG_RESULT([yes])
+ GC_SECTIONS="-Wl,--gc-sections";],
+ [AC_MSG_RESULT([no])
+ GC_SECTIONS="";])
+LDFLAGS=$save_LDFLAGS
+
+AC_SUBST([GC_SECTIONS])
+
+dnl
dnl compatibility symlinks
dnl
case "$host_os" in