build: add build and check target for coins.json

Makefile

@@ -70,4 +70,7 @@ protobuf_check: ## check that generated protobuf headers are up to date
 	./tools/build_protobuf --check
 
 gen:  mocks templates protobuf ## regeneate auto-generated files from sources
+	make -C python coins_json
+
 gen_check: mocks_check templates_check protobuf_check ## check validity of auto-generated files
+	make -C python coins_json_check

python/Makefile

@@ -11,16 +11,14 @@ clean-gen: ## remove generated files
 	rm -f trezorlib/messages/*.py
 	rm -f trezorlib/coins.json
 
+coins_json:
+	./helper-scripts/build-coins-json.sh
+
+coins_json_check:
+	./helper-scripts/build-coins-json.sh --check
+
 gen: clean-gen
-	$(PYTHON) ../common/tools/cointool.py dump \
-		--list --support \
-		--include-type=bitcoin \
-		--exclude=icon \
-		-o trezorlib/coins.json
-	$(PYTHON) ../common/protob/pb2py \
-		-o trezorlib/messages \
-		-P ..protobuf \
-		../common/protob/*.proto
+	make -C .. gen
 
 build:
 	$(SETUP) build

python/helper-scripts/build-coins-json.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+cd $(dirname $0)/..
+
+DEST=trezorlib/coins.json
+
+BUILD_COINS_AT="../common/tools/cointool.py dump \
+    --list --support \
+    --include-type=bitcoin \
+    --exclude=icon \
+    -o \
+"
+
+if [ "$1" == "--check" ]; then
+    TMP=$(mktemp)
+    $BUILD_COINS_AT $TMP
+    diff -q $DEST $TMP
+    if [ "$?" -ne 0 ]; then
+        echo "Please run $0"
+    fi
+    rm $TMP
+    exit $ERR
+else
+    $BUILD_COINS_AT $DEST
+fi

python/trezorlib/coins.py

@@ -24,7 +24,7 @@ COINS_JSON = os.path.join(os.path.dirname(__file__), "coins.json")
 
 def _load_coins_json():
     # Load coins.json to local variables
-    # NOTE: coins.json is generated via `make generated` command.
+    # NOTE: coins.json is generated via `make coins_json` command.
     with open(COINS_JSON) as coins_json:
         return json.load(coins_json)