Makefiles: various improvements (cosmos#6101)

Don't reinstall proto tools unconditionally every time
one runs make.

On most Linux systems, /usr/local is writable by root only.
Allow users to customise installation directory by passing
PREFIX to make command line, e.g.:

 $ make PREFIX=~/.local

.gitignore

@@ -19,6 +19,7 @@ docs/tutorial
 docs/node_modules
 dist
 tools-stamp
+proto-tools-stamp
 
 # Data - ideally these don't exist
 baseapp/data/*

Makefile

@@ -253,7 +253,7 @@ devdoc-update:
 ###                                Protobuf                                 ###
 ###############################################################################
 
-proto-all: proto-gen proto-lint proto-check-breaking
+proto-all: proto-tools proto-gen proto-lint proto-check-breaking
 
 proto-gen:
 	@./scripts/protocgen.sh

contrib/devtools/Makefile

@@ -1,6 +1,3 @@
-.PHONY: all tools tools-clean statik runsim \
-protoc buf protoc-gen-buf-check-breaking protoc-gen-buf-check-lint protoc-gen-gocosmos
-
 ###
 # Find OS and Go environment
 # GO contains the Go binary
@@ -18,8 +15,6 @@ ifeq ($(GO),)
   $(error could not find go. Is it in PATH? $(GO))
 endif
 
-all: tools
-
 ###############################################################################
 ###                                Functions                                ###
 ###############################################################################
@@ -41,20 +36,26 @@ mkfile_dir := $(shell cd $(shell dirname $(mkfile_path)); pwd)
 ###                                 Tools                                   ###
 ###############################################################################
 
-BIN ?= /usr/local/bin
+PREFIX ?= /usr/local
+BIN ?= $(PREFIX)/bin
 UNAME_S ?= $(shell uname -s)
 UNAME_M ?= $(shell uname -m)
 
 GOPATH ?= $(shell $(GO) env GOPATH)
 GITHUBDIR := $(GOPATH)$(FS)src$(FS)github.com
 
-BUF_VERSION ?= 0.7.0
+BUF_VERSION ?= 0.11.0
 
 TOOLS_DESTDIR  ?= $(GOPATH)/bin
 STATIK         = $(TOOLS_DESTDIR)/statik
 RUNSIM         = $(TOOLS_DESTDIR)/runsim
 
-tools: protoc buf statik runsim
+tools: tools-stamp
+tools-stamp: proto-tools statik runsim
+	# Create dummy file to satisfy dependency and avoid
+	# rebuilding when this Makefile target is hit twice
+	# in a row.
+	touch $@
 
 # Install the runsim binary with a temporary workaround of entering an outside
 # directory as the "go get" command ignores the -mod option and will polute the
@@ -84,39 +85,36 @@ ifeq ($(UNAME_S),Darwin)
   PROTOC_ZIP ?= protoc-3.11.2-osx-x86_64.zip
 endif
 
-protoc:
+proto-tools: proto-tools-stamp
+proto-tools-stamp:
 	@echo "Installing protoc compiler..."
 	@(cd /tmp; \
 	curl -OL "https://github.com/protocolbuffers/protobuf/releases/download/v${PROTOC_VERSION}/${PROTOC_ZIP}"; \
-	unzip -o ${PROTOC_ZIP} -d /usr/local bin/protoc; \
-	unzip -o ${PROTOC_ZIP} -d /usr/local 'include/*'; \
+	unzip -o ${PROTOC_ZIP} -d $(PREFIX) bin/protoc; \
+	unzip -o ${PROTOC_ZIP} -d $(PREFIX) 'include/*'; \
 	rm -f ${PROTOC_ZIP})
 
-protoc-gen-gocosmos:
-	@echo "Installing protoc-gen-gocosmos..."
-	@go install github.com/regen-network/cosmos-proto/protoc-gen-gocosmos
+	@echo "Installing protoc-gen-buf-check-breaking..."
+	@curl -sSL \
+    "https://github.com/bufbuild/buf/releases/download/v${BUF_VERSION}/protoc-gen-buf-check-breaking-${UNAME_S}-${UNAME_M}" \
+    -o "${BIN}/protoc-gen-buf-check-breaking" && \
+	chmod +x "${BIN}/protoc-gen-buf-check-breaking"
 
-buf: protoc-gen-buf-check-breaking protoc-gen-buf-check-lint
 	@echo "Installing buf..."
 	@curl -sSL \
     "https://github.com/bufbuild/buf/releases/download/v${BUF_VERSION}/buf-${UNAME_S}-${UNAME_M}" \
     -o "${BIN}/buf" && \
 	chmod +x "${BIN}/buf"
 
-protoc-gen-buf-check-breaking:
-	@echo "Installing protoc-gen-buf-check-breaking..."
-	@curl -sSL \
-    "https://github.com/bufbuild/buf/releases/download/v${BUF_VERSION}/protoc-gen-buf-check-breaking-${UNAME_S}-${UNAME_M}" \
-    -o "${BIN}/protoc-gen-buf-check-breaking" && \
-	chmod +x "${BIN}/protoc-gen-buf-check-breaking"
+	touch $@
 
-protoc-gen-buf-check-lint:
-	@echo "Installing protoc-gen-buf-check-lint..."
-	@curl -sSL \
-    "https://github.com/bufbuild/buf/releases/download/v${BUF_VERSION}/protoc-gen-buf-check-lint-${UNAME_S}-${UNAME_M}" \
-    -o "${BIN}/protoc-gen-buf-check-lint" && \
-	chmod +x "${BIN}/protoc-gen-buf-check-lint"
+protoc-gen-gocosmos:
+	@echo "Installing protoc-gen-gocosmos..."
+	@go install github.com/regen-network/cosmos-proto/protoc-gen-gocosmos
 
 tools-clean:
 	rm -f $(STATIK) $(GOLANGCI_LINT) $(RUNSIM)
-	rm -f tools-stamp
+	rm -f tools-stamp proto-tools-stamp
+
+.PHONY: tools-clean statik runsim \
+	protoc-gen-gocosmos