Set elf=yes if not defined already

glibc 2.16 dropped support for any binary format other than ELF, and the ELF variable has been removed too;
this causes a build failure when built as glibc addon with glibc >= 2.16, since it would not link to ld.so.
Defining ELF to 'yes' if not defined allows to retain compatibility with older glibc versions.

* Makefile [$(..) != ''] [$(elf) = ''] (elf): Define to 'yes'.

1 files changed, 4 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index fdfe3ae..c1d8d33 100644
--- a/Makefile
+++ b/Makefile
@@ -22,6 +22,10 @@ IN_GLIBC = no
 else
 # glibc build
 IN_GLIBC = yes
+# set elf=yes, to retain compatibility with glibc < 2.16
+ifeq ($(elf),)
+elf = yes
+endif
 endif
 
 ifeq ($(IN_GLIBC),no)