Makefile cleanup

1. Flattens nested if-else chains.
2. Replaces undefined-or-empty variable checks (`ifeq (,$(SOMEVAR))`) with `ifdef SOMEVAR`.
3. Merges two mostly duplicate sections of Windows-specific overrides.
4. Removes is-empty checks before `+= $(VAR)` (no-op if `VAR` is empty).

Makefile

@@ -15,7 +15,7 @@ INSTALL ?= install
 CFLAGS ?= -Wall
 CXXFLAGS ?= -Wall
 LDFLAGS ?= -Wall
-ifeq "x$(COVERAGE)" "x"
+ifndef COVERAGE
  CFLAGS += -O2
  CXXFLAGS += -O2
  LDFLAGS += -O2
@@ -28,39 +28,25 @@ CAT ?= $(if $(filter $(OS),Windows_NT),type,cat)
 
 ifneq (,$(findstring /cygdrive/,$(PATH)))
  UNAME := Cygwin
+else ifneq (,$(findstring Windows_NT,$(OS)))
+ UNAME := Windows
+else ifneq (,$(findstring mingw32,$(MAKE)))
+ UNAME := Windows
+else ifneq (,$(findstring MINGW32,$(shell uname -s)))
+ UNAME := Windows
 else
- ifneq (,$(findstring Windows_NT,$(OS)))
- UNAME := Windows
- else
- ifneq (,$(findstring mingw32,$(MAKE)))
- UNAME := Windows
- else
- ifneq (,$(findstring MINGW32,$(shell uname -s)))
- UNAME = Windows
- else
- UNAME := $(shell uname -s)
- endif
- endif
- endif
-endif
-
-ifeq ($(SASS_LIBSASS_PATH),)
- SASS_LIBSASS_PATH = $(abspath $(CURDIR))
+ UNAME := $(shell uname -s)
 endif
 
-ifeq ($(LIBSASS_VERSION),)
+ifndef LIBSASS_VERSION
  ifneq ($(wildcard ./.git/ ),)
  LIBSASS_VERSION ?= $(shell git describe --abbrev=4 --dirty --always --tags)
  endif
-endif
-
-ifeq ($(LIBSASS_VERSION),)
  ifneq ($(wildcard VERSION),)
  LIBSASS_VERSION ?= $(shell $(CAT) VERSION)
  endif
 endif
-
-ifneq ($(LIBSASS_VERSION),)
+ifdef LIBSASS_VERSION
  CFLAGS += -DLIBSASS_VERSION="\"$(LIBSASS_VERSION)\""
  CXXFLAGS += -DLIBSASS_VERSION="\"$(LIBSASS_VERSION)\""
 endif
@@ -82,7 +68,10 @@ else
  LDFLAGS += -std=c++0x
 endif
 
-ifneq ($(SASS_LIBSASS_PATH),)
+ifndef SASS_LIBSASS_PATH
+ SASS_LIBSASS_PATH = $(abspath $(CURDIR))
+endif
+ifdef SASS_LIBSASS_PATH
  CFLAGS += -I $(SASS_LIBSASS_PATH)/include
  CXXFLAGS += -I $(SASS_LIBSASS_PATH)/include
 else
@@ -91,18 +80,11 @@ else
  CXXFLAGS += -I include
 endif
 
-ifneq ($(EXTRA_CFLAGS),)
- CFLAGS += $(EXTRA_CFLAGS)
-endif
-ifneq ($(EXTRA_CXXFLAGS),)
- CXXFLAGS += $(EXTRA_CXXFLAGS)
-endif
-ifneq ($(EXTRA_LDFLAGS),)
- LDFLAGS += $(EXTRA_LDFLAGS)
-endif
+CFLAGS += $(EXTRA_CFLAGS)
+CXXFLAGS += $(EXTRA_CXXFLAGS)
+LDFLAGS += $(EXTRA_LDFLAGS)
 
 LDLIBS = -lm
-
 ifneq ($(BUILD),shared)
  LDLIBS += -lstdc++
 endif
@@ -142,7 +124,7 @@ ifeq ($(DEBUG),1)
  BUILD := debug-$(BUILD)
 endif
 
-ifeq (,$(TRAVIS_BUILD_DIR))
+ifndef TRAVIS_BUILD_DIR
  ifeq ($(OS),SunOS)
  PREFIX ?= /opt/local
  else
@@ -152,54 +134,34 @@ else
  PREFIX ?= $(TRAVIS_BUILD_DIR)
 endif
 
-
 SASS_SASSC_PATH ?= sassc
 SASS_SPEC_PATH ?= sass-spec
 SASS_SPEC_SPEC_DIR ?= spec
 SASSC_BIN = $(SASS_SASSC_PATH)/bin/sassc
 RUBY_BIN = ruby
 
+RESOURCES =
+STATICLIB = lib/libsass.a
+SHAREDLIB = lib/libsass.so
 LIB_STATIC = $(SASS_LIBSASS_PATH)/lib/libsass.a
 LIB_SHARED = $(SASS_LIBSASS_PATH)/lib/libsass.so
 
-ifeq (Windows,$(UNAME))
- ifeq (shared,$(BUILD))
- CFLAGS += -D ADD_EXPORTS
- CXXFLAGS += -D ADD_EXPORTS
- LIB_SHARED = $(SASS_LIBSASS_PATH)/lib/libsass.dll
- endif
-else
- ifneq (Cygwin,$(UNAME))
- CFLAGS += -fPIC
- CXXFLAGS += -fPIC
- LDFLAGS += -fPIC
- endif
-endif
-
 ifeq (Windows,$(UNAME))
  SASSC_BIN = $(SASS_SASSC_PATH)/bin/sassc.exe
-endif
-
-include Makefile.conf
-
-RESOURCES =
-STATICLIB = lib/libsass.a
-SHAREDLIB = lib/libsass.so
-ifeq (Windows,$(UNAME))
  RESOURCES += res/resource.rc
  SHAREDLIB = lib/libsass.dll
  ifeq (shared,$(BUILD))
  CFLAGS += -D ADD_EXPORTS
  CXXFLAGS += -D ADD_EXPORTS
+ LIB_SHARED = $(SASS_LIBSASS_PATH)/lib/libsass.dll
  endif
-else
- ifneq (Cygwin,$(UNAME))
- CFLAGS += -fPIC
- CXXFLAGS += -fPIC
- LDFLAGS += -fPIC
- endif
+else ifneq (Cygwin,$(UNAME))
+ CFLAGS += -fPIC
+ CXXFLAGS += -fPIC
+ LDFLAGS += -fPIC
 endif
 
+include Makefile.conf
 OBJECTS = $(addprefix src/,$(SOURCES:.cpp=.o))
 COBJECTS = $(addprefix src/,$(CSOURCES:.c=.o))
 RCOBJECTS = $(RESOURCES:.rc=.o)
@@ -303,11 +265,9 @@ sassc: $(SASSC_BIN)
  $(SASSC_BIN) -v
 
 version: $(SASSC_BIN)
- $(SASSC_BIN) -h
  $(SASSC_BIN) -v
 
-test: $(SASSC_BIN)
- $(RUBY_BIN) $(SASS_SPEC_PATH)/sass-spec.rb -V 3.5 -c $(SASSC_BIN) --impl libsass $(LOG_FLAGS) $(SASS_SPEC_PATH)/$(SASS_SPEC_SPEC_DIR)
+test: test_build
 
 test_build: $(SASSC_BIN)
  $(RUBY_BIN) $(SASS_SPEC_PATH)/sass-spec.rb -V 3.5 -c $(SASSC_BIN) --impl libsass $(LOG_FLAGS) $(SASS_SPEC_PATH)/$(SASS_SPEC_SPEC_DIR)