如何压缩此Makefile模式？

Question

如何将这样的Makefile段落对重写为一个段落？我有：

$(BUILD_DIR_DEBUG)/args.o: \
        $(SRC)/args.c \
        $(SRC)/args.h \
        $(SRC)/something_else.h
    $(CC) $(CFLAGS) $(CFLAGS_DEBUG) -c -o $@ $<

$(BUILD_DIR_RELEASE)/args.o: \
        $(SRC)/args.c \
        $(SRC)/args.h \
        $(SRC)/something_else.h
    $(CC) $(CFLAGS) $(CFLAGS_RELEASE) -c -o $@ $<

我很乐意得到这样的东西（不要假设正确的语法），但是我不知道如何定义这样的东西：

# ${BUILD_TYPE} to be iterated as "DEBUG" and "RELEASE" to get two current
# runtime rules from one actually written rule.
$(BUILD_DIR_$(BUILD_TYPE))/args.o: \
        $(SRC)/args.c \
        $(SRC)/args.h \
        $(SRC)/something_else.h
    $(CC) $(CFLAGS) $(CFLAGS_$(BUILD_TYPE)) -c -o $@ $<

Answer 1

简短答案：

ifeq ($(DEBUG), 1)
BUILD_DIR = $(BUILD_DIR_DEBUG)
CFLAGS = $(CFLAGS_DEBUG)
else
BUILD_DIR = $(BUILD_DIR_RELEASE)
CFLAGS = $(CFLAGS_RELEASE)
endif

$(BUILD_DIR)/args.o: \
        $(SRC)/args.c \
        $(SRC)/args.h \
        $(SRC)/something_else.h
    $(C) $(CFLAGS) -c -o $@ $<

并根据需要设置变量DEBUG。例如make DEBUG=1
另请参见：
How can I configure my makefile for debug and release builds?
https://www.gnu.org/software/make/manual/html_node/Conditional-Example.html