build: make building protobuf optional in depends

Summary:
Backport of core [[bitcoin/bitcoin#16871 | PR16871]].

The logic is reversed wrt core since we enable bip70 by default.

Depends on D5637.

Test Plan:
  make build-osx NO_PROTOBUF=1
Check that protobuf is not built.
  ../configure --prefix=$PWD/../depends/x86_64-apple-darwin16
Check in the summary that bip70 is disabled:
  with bip70  = no

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D5640

depends/Makefile

@@ -5,6 +5,7 @@ WORK_PATH = $(BASEDIR)/work
 BASE_CACHE ?= $(BASEDIR)/built
 SDK_PATH ?= $(BASEDIR)/SDKs
 NO_QT ?=
+NO_PROTOBUF ?=
 RAPIDCHECK ?=
 NO_WALLET ?=
 NO_ZMQ ?=
@@ -98,13 +99,15 @@ wallet_packages_$(NO_WALLET) = $(wallet_packages)
 upnp_packages_$(NO_UPNP) = $(upnp_packages)
 zmq_packages_$(NO_ZMQ) = $(zmq_packages)
 
+protobuf_packages_$(NO_PROTOBUF) = $(protobuf_packages)
 rapidcheck_packages_$(RAPIDCHECK) = $(rapidcheck_packages)
 
 packages += $($(host_arch)_$(host_os)_packages) $($(host_os)_packages) $(qt_packages_) $(wallet_packages_) $(upnp_packages_)
 native_packages += $($(host_arch)_$(host_os)_native_packages) $($(host_os)_native_packages)
 
-ifneq ($(qt_packages_),)
-native_packages += $(qt_native_packages)
+ifneq ($(protobuf_packages_),)
+native_packages += $(protobuf_native_packages)
+packages += $(protobuf_packages)
 endif
 
 ifneq ($(zmq_packages_),)
@@ -151,6 +154,7 @@ $(host_prefix)/share/config.site : config.site.in $(host_prefix)/.stamp_$(final_
             -e 's|@LDFLAGS@|$(strip $(host_LDFLAGS) $(host_$(release_type)_LDFLAGS))|' \
             -e 's|@no_qt@|$(NO_QT)|' \
             -e 's|@no_zmq@|$(NO_ZMQ)|' \
+            -e 's|@no_bip70@|$(NO_PROTOBUF)|' \
             -e 's|@no_wallet@|$(NO_WALLET)|' \
             -e 's|@no_upnp@|$(NO_UPNP)|' \
             -e 's|@debug@|$(DEBUG)|' \

depends/README.md

@@ -90,6 +90,7 @@ The following can be set when running make: make FOO=bar
     NO_UPNP: Don't download/build/cache packages needed for enabling upnp
     DEBUG: disable some optimizations and enable more runtime checking
     RAPIDCHECK: build rapidcheck (experimental, requires cmake)
+    NO_PROTOBUF: Don't download/build/cache protobuf (used for BIP70 support)
     HOST_ID_SALT: Optional salt to use when generating host package ids
     BUILD_ID_SALT: Optional salt to use when generating build package ids
     JOBS: Number of jobs to use for each package build

depends/config.site.in

@@ -37,6 +37,10 @@ if test -z $enable_zmq && test -n "@no_zmq@"; then
   enable_zmq=no
 fi
 
+if test -z $enable_bip70 && test -n "@no_bip70@"; then
+  enable_bip70=no
+fi
+
 if test x@host_os@ = xdarwin; then
   BREW=no
   PORT=no

depends/packages/packages.mk

@@ -1,7 +1,9 @@
 packages:=boost openssl libevent
 
-qt_native_packages = native_protobuf
-qt_packages = qrencode protobuf zlib
+protobuf_native_packages = native_protobuf
+protobuf_packages = protobuf
+
+qt_packages = qrencode zlib
 
 qt_linux_packages:=qt expat libxcb xcb_proto libXau xproto freetype fontconfig
 

doc/build-unix.md

@@ -39,7 +39,7 @@ Optional dependencies:
  miniupnpc   | UPnP Support     | Firewall-jumping support
  libdb       | Berkeley DB      | Wallet storage (only needed when wallet enabled)
  qt          | GUI              | GUI toolkit (only needed when GUI enabled)
- protobuf    | Payments in GUI  | Data interchange format used for payment protocol (only needed when GUI enabled)
+ protobuf    | Payments in GUI  | Data interchange format used for payment protocol (only needed when BIP70 enabled)
  libqrencode | QR codes in GUI  | Optional for generating QR codes (only needed when GUI enabled)
  univalue    | Utility          | JSON parsing and encoding (bundled version will be used unless --with-system-univalue passed to configure)
  libzmq3     | ZMQ notification | Optional, allows generating ZMQ notifications (requires ZMQ version >= 4.1.5)