Makefile: Simplify build targettc-makefile-improve

When building Gitaly binaries there are two ways to do this, with or
without build-id. How this was implemented was hard to understand.

This change streamlines how Gitaly binaries are built when not using
build-ids. This makes compilation a lot faster when there are no changes
made.

1 files changed, 12 insertions, 11 deletions

diff --git a/Makefile b/Makefile
index 9183f19db..b18c2b920 100644
--- a/Makefile
+++ b/Makefile
@@ -256,6 +256,7 @@ BENCHMARK_REPO   := ${TEST_REPO_DIR}/benchmark.git
 
 # Find all Gitaly commands.
 gitaly_commands      := $(notdir $(shell find ${SOURCE_DIR}/cmd -mindepth 1 -maxdepth 1 -type d -print))
+gitaly_binaries      := $(addprefix ${BUILD_DIR}/bin/, $(gitaly_commands))
 # Find all binaries, including Gitaly's and Git's
 find_command_binaries = $(wildcard ${BUILD_DIR}/bin/*)
 # Find all Go source files.
@@ -314,27 +315,27 @@ help:
 
 .PHONY: build
 ## Build Go binaries and install required Ruby Gems.
-build: ${SOURCE_DIR}/.ruby-bundle libgit2
+build: ${SOURCE_DIR}/.ruby-bundle libgit2 $(gitaly_binaries)
 
+$(gitaly_binaries): $(find_go_sources)
 ifdef WITHOUT_BUILD_ID
+	@ # Build all commands at once, which is a lot faster than one-by-one
 	go install -ldflags '${GO_LDFLAGS}' -tags "${GO_BUILD_TAGS}" $(addprefix ${GITALY_PACKAGE}/cmd/, $(gitaly_commands))
-endif
-
-ifndef WITHOUT_BUILD_ID
-build: $(gitaly_commands)
-
-.PHONY: $(gitaly_commands)
-$(gitaly_commands):
-	${Q}go install -ldflags '${GO_LDFLAGS}' -tags "${GO_BUILD_TAGS}" $(addprefix ${GITALY_PACKAGE}/cmd/, $@)
+else
+	@ # Because each command will get a unique build-id, build each command separately
+	${Q}go install -ldflags '${GO_LDFLAGS}' -tags "${GO_BUILD_TAGS}" $(addprefix ${GITALY_PACKAGE}/cmd/, ${@F})
 	@ # To compute a unique and deterministic value for GNU build-id, we build the Go binary a second time.
 	@ # From the first build, we extract its unique and deterministic Go build-id, and use that to derive
 	@ # comparably unique and deterministic GNU build-id to inject into the final binary.
 	@ # If we cannot extract a Go build-id, we punt and fallback to using a random 32-byte hex string.
 	@ # This fallback is unique but non-deterministic, making it sufficient to avoid generating the
 	@ # GNU build-id from the empty string and causing guaranteed collisions.
-	GO_BUILD_ID=$$( go tool buildid $(addprefix ${BUILD_DIR}/bin/, $@) || openssl rand -hex 32 ) && \
+	GO_BUILD_ID=$$( go tool buildid $@ || openssl rand -hex 32 ) && \
 	GNU_BUILD_ID=$$( echo $$GO_BUILD_ID | sha1sum | cut -d' ' -f1 ) && \
-	go install -ldflags '${GO_LDFLAGS}'" -B 0x$$GNU_BUILD_ID" -tags "${GO_BUILD_TAGS}" $(addprefix ${GITALY_PACKAGE}/cmd/, $@)
+	go install -ldflags '${GO_LDFLAGS}'" -B 0x$$GNU_BUILD_ID" -tags "${GO_BUILD_TAGS}" $(addprefix ${GITALY_PACKAGE}/cmd/, ${@F})
+
+# Ensure binaries get a new build-id on every run of `make build`
+.PHONY: $(gitaly_binaries)
 endif
 
 .PHONY: install