check conditions of make for equality of variables with an empty value

Makefile

@@ -6,12 +6,12 @@
 -include $(HOME)/.mkimage/profiles.mk
 
 # for immediate assignment
-ifndef ARCH
+ifeq (,$(ARCH))
 ARCH := $(shell arch \
 	| sed 's/i686/i586/; s/armv7.*/armh/; s/armv.*/arm/')
 endif
 
-ifndef ARCHES
+ifeq (,$(ARCHES))
 ARCHES := $(ARCH)
 endif
 

doc/Makefile

 # build asciidoc books
 
-ifdef BUILDDIR
+ifneq (,$(BUILDDIR))
 DEST = -D "$(BUILDDIR)"
 endif
 
-ifdef DEBUG
+ifneq (,$(DEBUG))
 VERBOSE = --verbose
 endif
 

features.in/00example/generate.mk

@@ -10,7 +10,7 @@
 
 include $(BUILDDIR)/distcfg.mk
 
-ifndef 00EXAMPLE
+ifeq (,$(00EXAMPLE))
 $(warning this is an example, who might want to include it? :])
 endif
 

features.in/Makefile

 # step 3: copy the needed features to $(BUILDDIR)
 #         (only regarding the needed subprofiles)
-
-ifndef BUILDDIR
+ifeq (,$(BUILDDIR))
 
 help/plus all: banner
 	@$(call grepper,'^+')

features.in/build-vm/lib/90-build-vm.mk

@@ -10,7 +10,7 @@ IMAGE_PACKAGES = $(DOT_BASE) \
 IMAGE_PACKAGES_REGEXP = $(THE_PACKAGES_REGEXP) \
                         $(BASE_PACKAGES_REGEXP)
 
-ifdef EFI_BOOTLOADER
+ifneq (,$(EFI_BOOTLOADER))
 VM_BOOTLOADER=$(EFI_BOOTLOADER)
 else
 VM_BOOTLOADER=$(BASE_BOOTLOADER)
@@ -30,7 +30,7 @@ VM_XZ_COMMAND ?= xz -T0 -f
 RECOVERY_LINE ?= Press ENTER to start
 
 # tarball save
-ifdef VM_SAVE_TARBALL
+ifneq (,$(VM_SAVE_TARBALL))
 ifeq (,$(filter-out img img.xz qcow2 qcow2c vdi vmdk vhd,$(IMAGE_TYPE)))
 ifeq (,$(filter-out tar tar.gz tar.xz,$(VM_SAVE_TARBALL)))
 SAVE_TARBALL := convert-image/$(VM_SAVE_TARBALL)
@@ -69,7 +69,7 @@ prepare-tarball-qemu:
 		tar -rf "$(VM_TARBALL)" ./.host/qemu*) ||:
 
 convert-image/tar:
-ifdef SAVE_TARBALL
+ifneq (,$(SAVE_TARBALL))
 	cp "$(VM_TARBALL)" "$(VM_OUT_TARBALL)"
 else
 	mv "$(VM_TARBALL)" "$(VM_OUT_TARBALL)"

features.in/dev/config.mk

@@ -30,7 +30,7 @@ ifeq (,$(filter-out x86_64 ,$(ARCH)))
 endif
 
 use/dev/builder/full: use/dev use/dev/builder/live use/dev/repo
-ifdef BIGRAM
+ifneq (,$(BIGRAM))
 	@$(call set,KFLAVOURS,$(BIGRAM))
 endif
 	@$(call add,THE_LISTS,$(call tags,server extra))

features.in/grub/generate.mk

-ifdef BUILDDIR
+ifneq (,$(BUILDDIR))
 
 # in seconds
 DEFAULT_TIMEOUT = 60
@@ -8,28 +8,28 @@ DEFAULT_TIMEOUT = 60
 
 include $(BUILDDIR)/distcfg.mk
 
-ifndef BOOTLOADER
+ifeq (,$(BOOTLOADER))
 $(error grub feature enabled but BOOTLOADER undefined)
 endif
 
 STAGE1_INITRD_BOOTARGS := $(STAGE1_INITRD_TYPEARGS)=$(STAGE1_INITRD_BOOTMETHOD)
 
-ifndef GRUB_DIRECT
+ifeq (,$(GRUB_DIRECT))
 # SUBPROFILES are considered GRUB_CFG too
 # (note these can appear like stage2@live);
 # 01defaults.cfg is included indefinitely
 GRUB_CFG := $(GRUB_CFG) $(SUBPROFILE_DIRS) defaults fwsetup_efi
 endif
 
-ifdef GRUB_UI
+ifneq (,$(GRUB_UI))
 GRUB_CFG := $(GRUB_CFG) gfxterm
 endif
 
-ifdef LOCALE
+ifneq (,$(LOCALE))
 GRUB_CFG := $(GRUB_CFG) lang
 endif
 
-ifdef KFLAVOURS
+ifneq (,$(KFLAVOURS))
 ifneq ($(words $(KFLAVOURS)),1)
 GRUB_CFG := $(GRUB_CFG) kernel
 endif

features.in/initrd-bootchain/generate.mk

 # set up initrd-bootchain config
 
-ifdef BUILDDIR
+ifneq (,$(BUILDDIR))
 
 include $(BUILDDIR)/distcfg.mk
 

features.in/install2/install2/stage2cfg.mk

 # stage2 mod: build install2 subprofile (installer "live" part)
 
-ifndef INSTALLER
+ifeq (,$(INSTALLER))
 $(error install2 feature enabled but INSTALLER undefined)
 endif
 

features.in/live/generate.mk

 # set up livecd browser redirection page
 
-ifdef BUILDDIR
+ifneq (,$(BUILDDIR))
 
 include $(BUILDDIR)/distcfg.mk
 
-ifndef HOMEPAGE
+ifeq (,$(HOMEPAGE))
 HOMEPAGE = http://altlinux.org/
 endif
 
-ifndef HOMENAME
+ifeq (,$(HOMENAME))
 HOMENAME = ALT
 endif
 
-ifndef HOMEWAIT
+ifeq (,$(HOMEWAIT))
 HOMEWAIT = 3
 endif
 

features.in/net-ssh/generate.mk

-ifdef BUILDDIR
+ifneq (,$(BUILDDIR))
 
 include $(BUILDDIR)/distcfg.mk
 

features.in/syslinux/generate.mk

-ifdef BUILDDIR
+ifneq (,$(BUILDDIR))
 
 # in deciseconds
 DEFAULT_TIMEOUT = 600
@@ -8,7 +8,7 @@ DEFAULT_TIMEOUT = 600
 
 include $(BUILDDIR)/distcfg.mk
 
-ifndef BOOTLOADER
+ifeq (,$(BOOTLOADER))
 $(error syslinux feature enabled but BOOTLOADER undefined)
 endif
 
@@ -16,14 +16,14 @@ STAGE1_INITRD_BOOTARGS := $(STAGE1_INITRD_TYPEARGS)=$(STAGE1_INITRD_BOOTMETHOD)
 
 # UI is backed by modules in modern syslinux
 # (except for built-in text prompt)
-ifdef SYSLINUX_UI
+ifneq (,$(SYSLINUX_UI))
 SYSLINUX_MODULES := $(SYSLINUX_MODULES) $(SYSLINUX_UI)
 else
 $(warning no syslinux ui configured, default is now none)
 SYSLINUX_UI := none
 endif
 
-ifndef SYSLINUX_DIRECT
+ifeq (,$(SYSLINUX_DIRECT))
 # SUBPROFILES are considered SYSLINUX_CFG too
 # (note these can appear like stage2@live);
 # 01defaults.cfg is included indefinitely

image.in/Makefile

@@ -36,7 +36,7 @@ IMAGEDIR := $(wildcard $(IMAGEDIR))
 IMAGE_SORTDIR := $(wildcard $(SORTDIR))
 
 # use distro version in image name if defined
-ifdef DISTRO_VERSION
+ifneq (,$(DISTRO_VERSION))
 IMAGE_VERSION := -$(DISTRO_VERSION)
 IMAGE_VER_LINK := $(IMAGE_NAME)$(IMAGE_VERSION)-latest-$(ARCH).$(IMAGE_TYPE)
 endif

image.in/functions.mk

 ifneq (clean,$(MAKECMDGOALS))
 ifneq (distclean,$(MAKECMDGOALS))
 
-ifndef INCLUDED_FUNCTIONS_MK
+ifeq (,$(INCLUDED_FUNCTIONS_MK))
 INCLUDED_FUNCTIONS_MK = 1
 
 # globals

lib/boot.mk

-ifndef MKIMAGE_PROFILES
+ifeq (,$(MKIMAGE_PROFILES))
 $(error this makefile is designed to be included in toplevel one)
 endif
 

lib/build.mk

@@ -6,12 +6,12 @@ MAX_LINES = 200
 MAX_ERRORS = 5
 GOTCHA := ^(((\*\* )?(E:|[Ee]rror|[Ww]arning).*)|(.* (FAILURE|FATAL|ERROR|conflicts|Conflicts:|Depends:) .*)|(.* (Stop|failed|not found)\.)|(not allowed))$$
 
-ifndef MKIMAGE_PROFILES
+ifeq (,$(MKIMAGE_PROFILES))
 $(error this makefile is designed to be included in toplevel one)
 endif
 
 # try not to bog down the system, both CPU and I/O wise
-ifdef NICE
+ifneq (,$(NICE))
 START := nice $(shell ionice -c3 echo "ionice -c3" 2>/dev/null)
 endif
 

lib/check.mk

-ifndef MKIMAGE_PROFILES
+ifeq (,$(MKIMAGE_PROFILES))
 $(error this makefile is designed to be included in toplevel one)
 endif
 

lib/clean.mk

@@ -8,12 +8,12 @@ SYMLINK = build
 # tmpfs-sparing extra rule: cleanup workdir after completing each stage
 # (as packed results are saved this only lowers RAM pressure)
 # NB: it's useful enough to be enabled by default in DEBUG abscence
-ifndef DEBUG
+ifeq (,$(DEBUG))
 CLEAN ?= 1
 endif
-ifdef CLEAN
+ifneq (,$(CLEAN))
 export GLOBAL_CLEAN_WORKDIR = clean-current
-ifdef DEBUG
+ifneq (,$(DEBUG))
 WARNING = (NB: DEBUG scope is limited when CLEAN is enabled)
 endif
 endif

lib/distro.mk

 # step 2: build up distribution's configuration
 
-ifndef MKIMAGE_PROFILES
+ifeq (,$(MKIMAGE_PROFILES))
 $(error this makefile is designed to be included in toplevel one)
 endif
 

lib/log.mk

@@ -2,7 +2,7 @@
 # you can add plain $(LOG) to a rule recipe line to moderate it
 # (logfile is automatically truncated during profile/init)
 
-ifndef MKIMAGE_PROFILES
+ifeq (,$(MKIMAGE_PROFILES))
 $(error this makefile is designed to be included in toplevel one)
 endif
 
@@ -17,7 +17,7 @@ endif
 BUILDLOG ?= $(BUILDDIR)/$(BUILD_LOG)
 
 # LOG holds a redirecting postprocessor
-ifdef DEBUG
+ifneq (,$(DEBUG))
 # 1) makefile target; 2) also passed to script hooks
 GLOBAL_DEBUG := debug
 GLOBAL_VERBOSE ?= $(DEBUG)

lib/profile.mk

-ifndef MKIMAGE_PROFILES
+ifeq (,$(MKIMAGE_PROFILES))
 $(error this makefile is designed to be included in toplevel one)
 endif
 
@@ -6,7 +6,7 @@ ifneq (,$(filter-out $(DIRECT_TARGETS),$(MAKECMDGOALS)))
 # this could have come from env; or could be symlinked; or is made anew
 # (the reuse rationale is avoiding extra tmpdir lookups)
 # NB: immediate assignment matters
-ifndef BUILDDIR
+ifeq (,$(BUILDDIR))
 BUILDLINK := $(realpath $(SYMLINK))
 BUILDDIR  := $(shell \
 if [ -s "$(SYMLINK)" -a "$(NUM_TARGETS)" = 1 ] && \

lib/ve.mk

 # step 2: build up virtual environment's configuration
 
-ifndef MKIMAGE_PROFILES
+ifeq (,$(MKIMAGE_PROFILES))
 $(error this makefile is designed to be included in toplevel one)
 endif
 

lib/vm.mk

 # step 2: build up virtual machine's configuration
 
-ifndef MKIMAGE_PROFILES
+ifeq (,$(MKIMAGE_PROFILES))
 $(error this makefile is designed to be included in toplevel one)
 endif
 

main.mk

@@ -46,7 +46,7 @@ include conf.d/*.mk
 include features.in/*/config.mk
 
 # ensure the outdir is created and globbable
-ifdef IMAGEDIR
+ifneq (,$(IMAGEDIR))
 $(shell mkdir -p $(IMAGEDIR))
 IMAGEDIR := $(wildcard $(IMAGEDIR))
 endif

pkg.in/Makefile

@@ -2,7 +2,7 @@
 #         referenced in distro configuration (and only those!)
 #         over to $(BUILDDIR)
 
-ifndef BUILDDIR
+ifeq (,$(BUILDDIR))
 $(error BUILDDIR not defined)
 endif
 

pkg.in/groups/Makefile

 # step 3: copy package groups referenced in distro configuration
 #         (and only those!) over to $(BUILDDIR)
 
-ifndef BUILDDIR
+ifeq (,$(BUILDDIR))
 
 check all: check-parents check-echo check-pkglists; @:
 

pkg.in/lists/Makefile

 # step 3: copy package lists referenced in distro configuration
 #         (and only those!) over to $(BUILDDIR)
-
-ifndef BUILDDIR
+ifeq (,$(BUILDDIR))
 pkgdups:
 	@find -type f ! -name README ! -name Makefile \
 	| grep -v '~$$' \

pkg.in/profiles/Makefile

 # step 3: copy package profiles referenced in distro configuration
 #         (and only those!) over to $(BUILDDIR)
 
-ifndef BUILDDIR
+ifeq (,$(BUILDDIR))
 $(error BUILDDIR not defined)
 endif
 

sub.in/Makefile

 # step 3: copy the needed subprofiles to $(BUILDDIR)
 
-ifndef BUILDDIR
+ifeq (,$(BUILDDIR))
 $(error BUILDDIR not defined)
 endif
 

sub.in/main/Makefile

 # step 4: build main subprofile (requisite + optional packages for media)
 
-ifndef GLOBAL_BUILDDIR
+ifeq (,$(GLOBAL_BUILDDIR))
 $(error GLOBAL_BUILDDIR not defined)
 endif
 

sub.in/stage1/Makefile

 # step 4: build stage1 subprofile (installer bootstrap)
 
-ifndef GLOBAL_BUILDDIR
+ifeq (,$(GLOBAL_BUILDDIR))
 $(error GLOBAL_BUILDDIR not defined)
 endif
 
@@ -8,7 +8,7 @@ include $(GLOBAL_BUILDDIR)/distcfg.mk
 include $(GLOBAL_BUILDDIR)/functions.mk
 include $(MKIMAGE_PREFIX)/config.mk
 
-ifndef BOOTLOADER
+ifeq (,$(BOOTLOADER))
 $(error BOOTLOADER not defined)
 endif
 GLOBAL_BOOTLOADER := $(BOOTLOADER)

sub.in/stage2/Makefile

@@ -3,7 +3,7 @@
 # NB: stage2 is not standalone but rather a common base
 #     for all livecd images (installer, live, rescue)
 
-ifndef GLOBAL_BUILDDIR
+ifeq (,$(GLOBAL_BUILDDIR))
 $(error GLOBAL_BUILDDIR not defined)
 endif
 
@@ -54,7 +54,7 @@ IMAGE_PACKAGES_REGEXP += $(call kpackages, \
 -include $(sort $(wildcard lib/*.mk))
 
 # see also ./scripts.d/99-elf-stats
-ifdef GLOBAL_SQUASHFS_SORT
+ifneq (,$(GLOBAL_SQUASHFS_SORT))
 ifeq (tight,$(SQUASHFS))
 CHROOT_PACKAGES += file
 pack-image: PACK_SQUASHFS_OPTS += -sort /.our/elf.lst