Question

我正在尝试创建一个makefile，它能够用于我希望在我的C项目中拥有的特定文件结构。请参阅下面的makefile以查看结构说明。

如果我运行make bin/obj/list.o，我会得到标题中指示的输出，即make: *** No rule to make target 'bin/obj/list.o'. Stop.。

这是我的makefile：

# compiler
CC                  := gcc

# name of target file
TARGET              := main_bin
TEST_TARGET         := test_bin

# directories and file info
INCDIR              := inc
SRCDIR              := src
TARGETDIR           := bin
OBJDIR              := $(TARGETDIR)/obj
TESTDIR             := tests
SRCEXT              := c
OBJEXT              := o

# flags and libraries
CFLAGS              := -Wall -O3 -I $(INCDIR)
CFLAGS_TEST         := -Wall -O3 -I $(INCDIR) -I $(TESTDIR)/$(INCDIR)
LIB                 := -lm

# Want a project structure like:
#
# root
#   ---- README
#   ---- LICENSE
#   ---- MAKEFILE
#   ---- .gitignore
#   ---- src
#           ---- main.c
#           ---- dir1
#               ---- source1.c
#           ---- ...
#           ---- dirN
#               ---- sourceN.c
#   ---- tests
#           ---- test_main.c
#           ---- inc
#               ---- test1.h
#               ---- ...
#               ---- testN.h
#           ---- tests1
#               ---- test1.c
#           ---- ...
#           ---- testsN
#               ---- testN.c
#           ---- bin
#               ---- test_executable
#               ---- obj
#                   ---- test_obj1.o
#                   ---- ...
#                   ---- test_objN.o
#   ---- inc
#           ---- header1.h
#           ---- ...
#           ---- headerN.h
#   ---- bin
#           ---- executable
#           ---- obj
#               ---- obj1.o
#               ---- ...
#               ---- objN.o
#

# find all src files that aren't in the root of the src directory
SOURCES             := $(shell find $(SRCDIR) -mindepth 2 -type f -name '*.$(SRCEXT)')

# find all src files that aren't in the root of the tests directory
TEST_SOURCES        := $(shell find $(TESTDIR)/$(SRCDIR) -mindepth 2 -type f -name '*.$(SRCEXT)')

# find the src file that is in the root of the src directory -- will contain main
MAIN_SOURCE         := $(shell find $(SRCDIR) -maxdepth 1 -type f -name '*.$(SRCEXT)')

# find the src file that is in the root of the tests directory -- will contain main for tests
TEST_MAIN_SOURCE    := $(shell find $(TESTDIR)/$(SRCDIR) -maxdepth 1 -type f -name '*.$(SRCEXT)')

# name the object files
OBJECTS             := $(addprefix $(OBJDIR)/,$(notdir $(SOURCES:.$(SRCEXT)=.$(OBJEXT))))
TEST_OBJECTS        := $(addprefix $(TESTDIR)/$(OBJDIR)/,$(notdir $(TEST_SOURCES:.$(SRCEXT)=.$(OBJEXT))))

# compile target
all: dirs $(TARGET)

# default to all
default: all

# create obj and bin directories if they don't exist
dirs:
    mkdir -p $(TARGETDIR) 
    mkdir -p $(OBJDIR)
    mkdir -p $(TESTDIR)/$(TARGETDIR) 
    mkdir -p $(TESTDIR)/$(OBJDIR)

# the main program relies on the file containing main under src and the objects
# link the object files into the executable
$(TARGET): $(OBJECTS) $(MAIN_SOURCE)
    @echo "Linking..."
    $(CC) -o $(TARGETDIR)/$@ $^ $(LIB)

# compile source files under the subdirectories of src into .o object files
$(OBJDIR)/%.$(OBJEXT): $(SRCDIR)/%.$(SRCEXT)
    @echo "Compiling..."
    $(CC) $(CFLAGS) -c -o $@ $^

# the test program relies on the file containing main under tests/src and the objects
# link the object files into the executable
$(TEST_TARGET): $(OBJECTS) $(TEST_OBJECTS) $(TEST_MAIN_SOURCE)
    @echo "Linking tests..."
    $(CC) -o $(TARGETDIR)/$@ $^ $(LIB)

# compile test source files under the subdirectories of tests/src into .o object files
$(TESTDIR)/$(OBJDIR)/%.$(OBJEXT): $(TESTDIR)/$(SRCDIR)/%.$(SRCEXT)
    @echo "Compiling tests..."
    $(CC) $(CFLAGS_TEST) -c -o $@ $^

# build the tests
test: dirs $(TEST_TARGET)
    $(TARGETDIR)/$(TEST_TARGET)

# useful to debug makefile, see what variables eval to 
vars:
    @echo "CFLAGS:          $(CFLAGS)"
    @echo "CFLAGS_TEST:     $(CFLAGS_TEST)"
    @echo "OBJDIR:          $(OBJDIR)"
    @echo "TESTDIR:     $(TESTDIR)"
    @echo "SOURCES:     $(SOURCES)"
    @echo "MAIN_SOURCE:     $(MAIN_SOURCE)"
    @echo "OBJECTS:     $(OBJECTS)"
    @echo "TEST_SOURCES:        $(TEST_SOURCES)"
    @echo "TEST_MAIN_SOURCE:    $(TEST_MAIN_SOURCE)"
    @echo "TEST_OBJECTS:        $(TEST_OBJECTS)"

# remove obj and bin
clean:
    @echo "Cleaning..."
    rm -rf $(OBJDIR)
    rm -rf $(TARGETDIR)
    rm -rf $(TESTDIR)/$(TARGETDIR) 
    rm -rf $(TESTDIR)/$(OBJDIR)

.PHONY: clean

具体来说，我认为这一行：

# compile source files under the subdirectories of src into .o object files
$(OBJDIR)/%.$(OBJEXT): $(SRCDIR)/%.$(SRCEXT)
    @echo "Compiling..."
    $(CC) $(CFLAGS) -c -o $@ $^

应该成为bin/obj/list.o的规则。我知道我的所有文件都存在，包括src/list/list.c和inc/list.h。

有谁知道为什么这条规则不满足bin/obj/list.o？

Answer 1

https://www.gnu.org/software/make/manual/make.html#index-explicit-rules_002c-secondary-expansion-of表示$^将扩展为通过$（SRCDIR）/%.$（SRCEXT）找到的每个文件。

我建议重新编写规则，使模式匹配更加明确：

$(OBJDIR)/%.o: $(SRCDIR)/%.c
        @echo "Compiling..."
        $(CC) $(CFLAGS) -c -o $@ $<

这样你就可以在.c和.o文件之间建立一对一的关系。

没有规则来制作目标＆＃bin; / obj / list.o＆＃39;

1 个答案: