Breaking Makefile into platform specific files

Fixed containerd#1270

Signed-off-by: Kunal Kushwaha <kushwaha_kunal_v7@lab.ntt.co.jp>

Makefile

@@ -19,21 +19,11 @@ endif
 WHALE = "🇩"
 ONI = "👹"
 FIX_PATH = $1
-ifeq ("$(OS)", "Windows_NT")
-	WHALE="+"
-	ONI="-"
-	FIX_PATH = $(subst /,\,$1)
-endif
 
 RELEASE=containerd-$(VERSION:v%=%).${GOOS}-${GOARCH}
 
 PKG=github.com/containerd/containerd
 
-# on SunOS default to gnu utilities for things like grep, sed, etc.
-ifeq ($(shell uname -s),SunOS)
-	export PATH := /usr/gnu/bin:$(PATH)
-endif
-
 # Project packages.
 PACKAGES=$(shell go list ./... | grep -v /vendor/)
 INTEGRATION_PACKAGE=${PKG}
@@ -49,24 +39,17 @@ TEST_REQUIRES_ROOT_PACKAGES=$(filter \
 
 # Project binaries.
 COMMANDS=ctr containerd containerd-stress
-ifneq ("$(GOOS)", "windows")
-	COMMANDS += containerd-shim
-endif
 BINARIES=$(addprefix bin/,$(COMMANDS))
-ifeq ("$(GOOS)", "windows")
-	BINARY_SUFFIX=".exe"
-endif
 
 GO_TAGS=$(if $(BUILDTAGS),-tags "$(BUILDTAGS)",)
 GO_LDFLAGS=-ldflags "-X $(PKG)/version.Version=$(VERSION) -X $(PKG)/version.Revision=$(REVISION) -X $(PKG)/version.Package=$(PKG) $(EXTRA_LDFLAGS)"
 
-# go test -race is only supported on the patforms listed below.
 TESTFLAGS_RACE=
-ifeq ($(filter \
-    linux/amd64 freebsd/amd64 darwin/amd64 windows/amd64, \
-    $(GOOS)/$(GOARCH)),$(GOOS)/$(GOARCH))
-	TESTFLAGS_RACE= -race
-endif
+
+#Detect the target os
+include Makefile.OS
+#include platform specific makefile
+include Makefile.$(target_os)
 
 # Flags passed to `go test`
 TESTFLAGS ?= -v $(TESTFLAGS_RACE)

Makefile.OS

@@ -0,0 +1,19 @@
+#Detect the OS, and return installos value same as GOOS
+target_os =
+ifeq ($(OS),Windows_NT)
+    target_os = windows
+else
+    UNAME_S := $(shell uname -s)
+    ifeq ($(UNAME_S),Linux)
+        target_os = linux
+    endif
+    ifeq ($(UNAME_S),Darwin)
+        target_os = darwin
+    endif
+    ifeq ($(UNAME_S),FreeBSD)
+        target_os = freebsd
+    endif
+    ifeq ($(UNAME_S),SunOS)
+        target_os = solaris
+    endif
+endif

Makefile.darwin

@@ -0,0 +1,5 @@
+#darwin specific settings
+COMMANDS += containerd-shim
+
+# supports go test -race
+TESTFLAGS_RACE= -race

Makefile.freebsd

@@ -0,0 +1,5 @@
+#freebsd specific settings
+COMMANDS += containerd-shim
+
+# supports go test -race
+TESTFLAGS_RACE= -race

Makefile.linux

@@ -0,0 +1,5 @@
+#linux specific settings
+COMMANDS += containerd-shim
+
+# supports go test -race
+TESTFLAGS_RACE= -race

Makefile.solaris

@@ -0,0 +1,6 @@
+#solaris specific settings
+
+# on SunOS default to gnu utilities for things like grep, sed, etc.
+export PATH := /usr/gnu/bin:$(PATH)
+
+COMMANDS += containerd-shim

Makefile.windows

@@ -0,0 +1,9 @@
+#Windows specific settings.
+WHALE = "+"
+ONI = "-"
+FIX_PATH = $(subst /,\,$1)
+
+BINARY_SUFFIX=".exe"
+
+# supports go test -race
+TESTFLAGS_RACE= -race