Makefile tips

[ih4cku]

static pattern rules

• Static pattern rules are like regular pattern rules except they apply only to a specific list of target files.
• They are more general than ordinary rules with multiple targets because the targets do not have to have identical prerequisites.
  • Their prerequisites must be analogous, but not necessarily identical.

References

• 4.12 Static Pattern Rules
• examples in Caffe

[ih4cku]

eliminate duplicated words

$(shell echo $(dir $(OBJS)) | xargs -n1 | sort -u)

[ih4cku]

predefined rules

OUTPUT_OPTION = -o $@
COMPILE.c = $(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c
LINK.o = $(CC) $(LDFLAGS) $(TARGET_ARCH)
LINK.c = $(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) $(TARGET_ARCH)

%: %.o
    $(LINK.o) $^ $(LDLIBS) -o $@

%.o: %.c
    $(COMPILE.c) $(OUTPUT_OPTION) $<

%: %.c
    $(LINK.c) $^ $(LDLIBS) -o $@

[ih4cku]

order-only prerequsites

there are 2 kinds of prerequisites:

• normal
  • not built in order, especially when parallel building
• order-only
  • before normal prerequisites
  • not included in $^

References

• 4.3 Types of Prerequisites
• In what order prerequisites will be made by the GNU make?
• examples in Caffe

[ih4cku]

my template

PROJECT := main

INC_DIR := include
SRC_DIR := src
BUILD_DIR := build
BIN_DIR := bin

BIN := $(BIN_DIR)/$(PROJECT)

CPPFLAGS := -I$(INC_DIR)
CXXFLAGS := -std=c++11 -O2

SRCS := $(shell find $(SRC_DIR) -name '*.cpp')
OBJS := $(patsubst $(SRC_DIR)/%.cpp,$(BUILD_DIR)/%.o,$(SRCS))
DEPS := $(patsubst $(SRC_DIR)/%.cpp,$(BUILD_DIR)/%.dpp,$(SRCS))

.PHONY: all run clean 

all: $(BIN) 

run: $(BIN)
    $(BIN)

$(BIN): $(OBJS) | bin_dir
    $(CXX) $(LDFLAGS) $^ $(LDLIBS) -o $@

$(OBJS): $(BUILD_DIR)/%.o: $(SRC_DIR)/%.cpp | build_dir
    $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c -o $@ $<

$(DEPS): $(BUILD_DIR)/%.dpp: $(SRC_DIR)/%.cpp | build_dir
    $(CXX) -MM $(CPPFLAGS) $< > $@.$$$$; \
    sed 's,\($*\)\.o[ :]*,$(BUILD_DIR)/\1.o $@ : ,g' < $@.$$$$ > $@; \
    rm -f $@.$$$$

build_dir:
    @mkdir -p $(shell echo $(dir $(OBJS)) | xargs -n1 | sort -u | xargs)

bin_dir:
    @mkdir -p $(BIN_DIR)

clean:
    rm -rf $(BIN_DIR) $(BUILD_DIR)

-include $(DEPS)

TODO

• Managing Projects with GNU Make Chapter 8.3 Dependency Generation
• Tom Tromey's advanced solution
• GNU make: clean target depends on includes