Makefile: use find to detect source files

The current list of sources doesn't list vendor sources and some other
.go files, requiring manual modifications to the Makefile to build
binaries. This change uses `find` (from Podman's Makefile) to detect .go
files across the repo.

Removes the validation script since we're no longer specifying sources
manually. And removes explicit *.go files as binary sources.

Signed-off-by: Danish Prakash <[email protected]>

Makefile

@@ -38,7 +38,12 @@ CNI_COMMIT := $(shell sed -n 's;^$(COMMENT) github.com/containernetworking/cni \
 
 EXTRA_LDFLAGS ?=
 BUILDAH_LDFLAGS := $(GO_LDFLAGS) '-X main.GitCommit=$(GIT_COMMIT) -X main.buildInfo=$(SOURCE_DATE_EPOCH) -X main.cniVersion=$(CNI_COMMIT) $(EXTRA_LDFLAGS)'
-SOURCES=*.go imagebuildah/*.go bind/*.go chroot/*.go copier/*.go define/*.go docker/*.go internal/config/*.go internal/mkcw/*.go internal/mkcw/types/*.go internal/parse/*.go internal/sbom/*.go internal/source/*.go internal/tmpdir/*.go internal/*.go internal/util/*.go internal/volumes/*.go manifests/*.go pkg/binfmt/*.go pkg/blobcache/*.go pkg/chrootuser/*.go pkg/cli/*.go pkg/completion/*.go pkg/formats/*.go pkg/jail/*.go pkg/overlay/*.go pkg/parse/*.go pkg/rusage/*.go pkg/sshagent/*.go pkg/umask/*.go pkg/util/*.go pkg/volumes/*.go util/*.go
+
+# This isn't what we actually build; it's a superset, used for target
+# dependencies. Basically: all *.go and *.c files, except *_test.go,
+# and except anything in a dot subdirectory. If any of these files is
+# newer than our target (bin/buildah), a rebuild is triggered.
+SOURCES=$(shell find . -path './.*' -prune -o \( \( -name '*.go' -o -name '*.c' \) -a ! -name '*_test.go' \) -print)
 
 LINTFLAGS ?=
 
@@ -68,7 +73,7 @@ static:
 	mkdir -p ./bin
 	cp -rfp ./result/bin/* ./bin/
 
-bin/buildah: $(SOURCES) cmd/buildah/*.go internal/mkcw/embed/entrypoint_amd64.gz
+bin/buildah: $(SOURCES) internal/mkcw/embed/entrypoint_amd64.gz
 	$(GO_BUILD) $(BUILDAH_LDFLAGS) $(GO_GCFLAGS) "$(GOGCFLAGS)" -o $@ $(BUILDFLAGS) ./cmd/buildah
 	test -z "${SELINUXOPT}" || chcon --verbose -t $(SELINUXTYPE) $@
 
@@ -98,13 +103,13 @@ bin/buildah.%:
 	mkdir -p ./bin
 	GOOS=$(word 2,$(subst ., ,$@)) GOARCH=$(word 3,$(subst ., ,$@)) $(GO_BUILD) $(BUILDAH_LDFLAGS) -o $@ -tags "containers_image_openpgp" ./cmd/buildah
 
-bin/imgtype: $(SOURCES) tests/imgtype/imgtype.go
+bin/imgtype: $(SOURCES)
 	$(GO_BUILD) $(BUILDAH_LDFLAGS) -o $@ $(BUILDFLAGS) ./tests/imgtype/imgtype.go
 
-bin/copy: $(SOURCES) tests/copy/copy.go
+bin/copy: $(SOURCES)
 	$(GO_BUILD) $(BUILDAH_LDFLAGS) -o $@ $(BUILDFLAGS) ./tests/copy/copy.go
 
-bin/tutorial: $(SOURCES) tests/tutorial/tutorial.go
+bin/tutorial: $(SOURCES)
 	$(GO_BUILD) $(BUILDAH_LDFLAGS) -o $@ $(BUILDFLAGS) ./tests/tutorial/tutorial.go
 
 bin/inet: tests/inet/inet.go
@@ -127,7 +132,6 @@ validate: install.tools
 	./tests/validate/whitespace.sh
 	./hack/xref-helpmsgs-manpages
 	./tests/validate/pr-should-include-tests
-	./hack/makefile_sources
 
 .PHONY: install.tools
 install.tools: