Use whitelist to find go files, run find only once (#10594)

- Use a whitelist-based approach to find *.go files so we can use
  standard find syntax. Also included is a change that files no
  longer pass a leading './' which should help performance further.

- Instead of running `find` multiple times in make because of the
  lazy evaluation, run it only once and add the bindata files when
  the bindata tag is present

This is another huge speedup on my machine of around 2000%.

Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>

Makefile

 SED_INPLACE := sed -i
 SHASUM ?= shasum -a 256
 HAS_GO = $(shell hash $(GO) > /dev/null 2>&1 && echo "GO" || echo "NOGO" )
+COMMA := ,
 
 ifeq ($(HAS_GO), GO)
 	GOPATH ?= $(shell $(GO) env GOPATH)
 
 ifeq ($(OS), Windows_NT)
 	EXECUTABLE ?= gitea.exe
-	FIND_PWD_REGEXP := find . -regextype posix-egrep
 else
 	EXECUTABLE ?= gitea
 	UNAME_S := $(shell uname -s)
-	FIND_PWD_REGEXP := find . -regextype posix-egrep
-	BUSYBOX := $(shell find --help 2>&1 | grep -o BusyBox)
 	ifeq ($(UNAME_S),Darwin)
 		SED_INPLACE := sed -i ''
-		FIND_PWD_REGEXP := find -E .
 	endif
 	ifeq ($(UNAME_S),FreeBSD)
 		SED_INPLACE := sed -i ''
-		FIND_PWD_REGEXP := find -E .
-	endif
-	ifeq ($(BUSYBOX),BusyBox)
-		FIND_PWD_REGEXP := find .
 	endif
 endif
 
 
 PACKAGES ?= $(filter-out code.gitea.io/gitea/integrations/migration-test,$(filter-out code.gitea.io/gitea/integrations,$(shell GO111MODULE=on $(GO) list -mod=vendor ./... | grep -v /vendor/)))
 
-GO_SOURCES ?= $(shell $(FIND_PWD_REGEXP) -regex '\./(node_modules|docs|public|options|contrib|data)' -prune -o -name "*.go" -type f -print)
-GO_SOURCES_OWN := $(filter-out ./vendor/% %/bindata.go, $(GO_SOURCES))
-
 WEBPACK_SOURCES := $(shell find web_src/js web_src/less -type f)
 WEBPACK_CONFIGS := webpack.config.js .eslintrc .stylelintrc
 WEBPACK_DEST := public/js/index.js public/css/index.css
 BINDATA_DEST := modules/public/bindata.go modules/options/bindata.go modules/templates/bindata.go
 BINDATA_HASH := $(addsuffix .hash,$(BINDATA_DEST))
 
+TAGS ?=
+TAGS_SPLIT := $(subst $(COMMA), ,$(TAGS))
+TAGS_EVIDENCE := $(MAKE_EVIDENCE_DIR)/tags
+
+GO_DIRS := cmd integrations models modules routers scripts services vendor
+GO_SOURCES := $(wildcard *.go)
+GO_SOURCES += $(shell find $(GO_DIRS) -type f -name "*.go" -not -path modules/options/bindata.go -not -path modules/public/bindata.go -not -path modules/templates/bindata.go)
+
+ifeq ($(filter $(TAGS_SPLIT),bindata),bindata)
+	GO_SOURCES += $(BINDATA_DEST)
+endif
+
+GO_SOURCES_OWN := $(filter-out vendor/% %/bindata.go, $(GO_SOURCES))
+
 FOMANTIC_CONFIGS := semantic.json web_src/fomantic/theme.config.less web_src/fomantic/_site/globals/site.variables
 FOMANTIC_DEST := public/fomantic/semantic.min.js public/fomantic/semantic.min.css
 FOMANTIC_DEST_DIR := public/fomantic
 
-TAGS ?=
-TAGS_EVIDENCE := $(MAKE_EVIDENCE_DIR)/tags
-
 #To update swagger use: GO111MODULE=on go get -u github.com/go-swagger/go-swagger/cmd/swagger@v0.20.1
 SWAGGER := GO111MODULE=on $(GO) run -mod=vendor github.com/go-swagger/go-swagger/cmd/swagger
 SWAGGER_SPEC := templates/swagger/v1_json.tmpl