From 99ca5e1a226304ea9f838123f96232b6f3f579ea Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Tue, 17 Oct 2017 19:04:02 -0700
Subject: [PATCH] Ensure that libsnark is built first, so its headers are
 available

---
 src/Makefile.am | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/Makefile.am b/src/Makefile.am
index 5bf092561..7cab29fda 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -36,11 +36,15 @@ LIBSNARK=snark/build/lib/libsnark.a
 LIBUNIVALUE=univalue/libunivalue.la
 LIBZCASH=libzcash.a
 
-# libsnark is added as a dependency here solely to ensure it is built early, so
-# that its header files are collated for use in later build steps.
-$(LIBSECP256K1): $(LIBSNARK) $(wildcard secp256k1/src/*) $(wildcard secp256k1/include/*)
+$(LIBSECP256K1): $(wildcard secp256k1/src/*) $(wildcard secp256k1/include/*)
 	$(AM_V_at)$(MAKE) $(AM_MAKEFLAGS) -C $(@D) $(@F)
 
+# A phony target is included here to ensure libsnark is built first, so that its
+# header files are collated for use in later build steps.
+# See https://stackoverflow.com/a/10726725
+-include collate-libsnark
+collate-libsnark: $(LIBSNARK)
+
 LIBSNARK_CXXFLAGS = -fPIC -DBINARY_OUTPUT -DNO_PT_COMPRESSION=1
 LIBSNARK_CONFIG_FLAGS = CURVE=ALT_BN128 MULTICORE=1 NO_PROCPS=1 NO_DOCS=1 STATIC=1 NO_SUPERCOP=1 FEATUREFLAGS=-DMONTGOMERY_OUTPUT NO_COPY_DEPINST=1
 
@@ -103,7 +107,7 @@ LIBZCASH_H = \
   zcash/util.h \
   zcash/Zcash.h
 
-.PHONY: FORCE check-symbols check-security
+.PHONY: FORCE collate-libsnark check-symbols check-security
 # bitcoin core #
 BITCOIN_CORE_H = \
   addrman.h \