Question

我有一个用于某些C ++代码的makefile（粘贴在下面），这有一个令人讨厌的问题，当我执行make clean时，依赖文件会被编译（在再次删除之前），这也会使make clean慢。依赖规则是

$(DEPENDDIR)%.d: %.cpp
    @mkdir -p $(DEPENDDIR)
    $(CXX) -M -MG -MT $(OBJECTDIR)$*.o $(CXXFLAGS) $< > $@

任何人都可以看到问题所在吗？

我尝试将依赖项移到对象被编译的部分，即：

$(OBJECTDIR)%.o: %.cpp
    @mkdir -p $(OBJECTDIR) # $(dir $@)
    @echo " "
    $(CXX) -M -MG -MT $@ $(CXXFLAGS) $< \
        -MF $(patsubst $(OBJECTDIR)%.o, $(DEPENDDIR)%.d, $@)

但是没有创建头文件version.hpp（并且编译失败）

KERNEL := $(shell uname -s)

PROGNAME=nextsim.exec

CXX = g++

# setting the C++ standard according to the gcc compiler version (from gcc-5.2, the default is C++14)
ifeq ($(shell echo `$(CXX) -dumpversion | cut -f1-2 -d.` \>= 5.2 | sed -e 's/\.//g' | bc),1)
    CXXFLAGS += -std=c++14
else
    CXXFLAGS += -std=c++11
endif

# add g++ option flags
CXXFLAGS += -ftemplate-depth-256 -Wno-inline \
        -fPIC -fopenmp \
        -DHAVE_CONFIG_H -D_MULTITHREADING_
ifdef NEXTSIM_COMPILE_VERBOSE
    CXXFLAGS += -v
endif

ifdef USE_OASIS
    CXXFLAGS += -DOASIS
    CXXFLAGS += -I $(NEXTSIMDIR)/modules/oasis/include
    LDFLAGS += -lgfortran
    LDFLAGS += -L $(NEXTSIMDIR)/lib -loasis
    CHAN = MPI1
    #LIBPSMILE = $(OASIS_DIR)/lib/libpsmile.${CHAN}.a $(OASIS_DIR)/lib/libmct.a $(OASIS_DIR)/lib/libmpeu.a $(OASIS_DIR)/lib/libscrip.a
endif

ifneq (,$(strip $(filter DEBUG Debug debug PROFILE Profile profile,$(NEXTSIM_BUILD_TYPE))))
    #ifeq ($(NEXTSIM_BUILD_TYPE),$(filter $(NEXTSIM_BUILD_TYPE),Debug debug))
    CXXFLAGS := $(filter-out -O3 -pthread,$(CXXFLAGS))
    CXXFLAGS += -g -O0 -DNDEBUG
ifneq (,$(strip $(filter PROFILE Profile profile,$(NEXTSIM_BUILD_TYPE))))
    CXXFLAGS += -DWITHGPERFTOOLS
endif
ifneq ($(KERNEL),Linux)
    CXXFLAGS += -Wl,-no_pie
endif
else
    CXXFLAGS += -O3 -pthread
endif

# add include paths
CXXFLAGS += -I $(NEXTSIMDIR)/core/include
CXXFLAGS += -isystem $(NEXTSIMDIR)/contrib/bamg/include # suppress annoying compilation warnings from -I
CXXFLAGS += -isystem $(NEXTSIMDIR)/contrib/mapx/include # suppress annoying compilation warnings from -I
# CXXFLAGS += -I $(NEXTSIMDIR)/contrib/interp/include

ifdef USE_ENSEMBLE
    CXXFLAGS += -DENSEMBLE
    CXXFLAGS += -I $(NEXTSIMDIR)/modules/enkf/perturbation/include
endif

ifdef USE_AEROBULK
        CXXFLAGS += -I $(AEROBULK_DIR)/include
        CXXFLAGS += -DAEROBULK
endif

# openmpi
CXXFLAGS += -I $(OPENMPI_INCLUDE_DIR)/

# petsc
CXXFLAGS += -I $(PETSC_DIR)/include

# boost
CXXFLAGS += -I $(BOOST_INCDIR)/ -I .

# netcdf
CXXFLAGS += -I $(NETCDF_DIR)/include

# gmsh
CXXFLAGS += -I $(GMSH_DIR)/include/gmsh

CXXFLAGS += -I /opt/local/include

ifeq ($(KERNEL),Linux)
    #CXXFLAGS += -std=c++0x -std=c++11 -pedantic -ftemplate-depth-256 -Wno-inline -fPIC -g -lm -pthread -v #-MMD -MP -lm -pthread -v

else

    ifeq ($(CXX),clang)
    CXXFLAGS += -stdlib=libc++
    endif

    CXXFLAGS += -I /usr/local/include #-I /opt/local/include/openmpi-mp

    #LDFLAGS += -Wl,-rpath,/usr/local/lib #-Wl,-rpath,/opt/local/lib/openmpi-mp
    #LDFLAGS += -L /usr/local/lib #-L /opt/local/lib/openmpi-mp -lmpi_cxx -lmpi -ldl -lstdc++ -lpthread

    ifeq ($(CXX),clang)
    LDFLAGS += -stdlib=libc++
    endif

endif

LDFLAGS += -L /usr/local/lib

LDFLAGS += -Wl,-rpath,$(OPENMPI_LIB_DIR)/
ifndef MACHINE_HEXAGON
    LDFLAGS += -L $(OPENMPI_LIB_DIR)/ -lmpi_cxx -lmpi -ldl -lstdc++ #-lpthread
else
    LDFLAGS += -L $(OPENMPI_LIB_DIR)/ -lmpichcxx -lmpich -ldl -lstdc++ #-lpthread #-lssl -luuid -lpthread -lrt
        LDFLAGS += -Wl,-rpath,$(BLAS_LAPACK_DIR)/lib
        LDFLAGS += -L $(BLAS_LAPACK_DIR)/lib -lsci_gnu_mp
endif

LDFLAGS += -Wl,-rpath,$(NETCDF_DIR)/lib -L $(NETCDF_DIR)/lib -lnetcdf_c++4

LDFLAGS += -Wl,-rpath,$(BOOST_LIBDIR)
LDFLAGS += -L $(BOOST_LIBDIR) -lboost_program_options -lboost_filesystem -lboost_system -lboost_serialization -lboost_mpi -lboost_date_time

LDFLAGS += -Wl,-rpath,$(PETSC_DIR)/lib
LDFLAGS += -L $(PETSC_DIR)/lib -lpetsc

LDFLAGS += -Wl,-rpath,$(NEXTSIMDIR)/lib
LDFLAGS += -L $(NEXTSIMDIR)/lib -lbamg
#LDFLAGS += -L $(NEXTSIMDIR)/lib -linterp
LDFLAGS += -L $(NEXTSIMDIR)/lib -lmapx
#LDFLAGS += -L $(NEXTSIMDIR)/lib -loasis

ifdef USE_ENSEMBLE
    LDFLAGS += -L $(NEXTSIMDIR)/lib -lpseudo2D
    LDFLAGS += -lgfortran
endif

ifdef USE_AEROBULK
        LDFLAGS += -L $(AEROBULK_DIR)/lib -laerobulk_cxx -laerobulk
        LDFLAGS += -lgfortran
endif

ifneq (,$(strip $(filter DEBUG Debug debug PROFILE Profile profile,$(NEXTSIM_BUILD_TYPE))))
#ifeq ($(NEXTSIM_BUILD_TYPE),$(filter $(NEXTSIM_BUILD_TYPE),Debug debug))
    LDFLAGS += -Wl,-rpath,/opt/local/lib
ifneq (,$(strip $(filter PROFILE Profile profile,$(NEXTSIM_BUILD_TYPE))))
    LDFLAGS += -L /opt/local/lib -lprofiler
endif
endif

LDFLAGS += -L $(NEXTSIMDIR)/lib -lnextsim

OBJECTDIR=$(NEXTSIMDIR)/objs/
DEPENDDIR=$(NEXTSIMDIR)/.deps/
BINARYDIR=bin/

# C++ files
CXXSRCDIR=.
CXXHDRDIR=.
CXXSRC=$(wildcard $(CXXSRCDIR)/*.cpp)
# We must exclude the version.hpp file from the list of header files because otherwise we get a circular dependency
CXXHDR=$(filter-out $(CXXHDRDIR)/version.hpp, $(wildcard $(CXXHDRDIR)/*.hpp))

OBJS=$(CXXSRC:%.cpp=$(OBJECTDIR)%.o)
DEPS=$(CXXSRC:%.cpp=$(DEPENDDIR)%.d)

# Rules to always execute.
.PHONY: exec clean mrproper all cleanall mrproperall

# Default action.
exec: $(PROGNAME)

# Create a header file with the git version
version.hpp: version.sh $(CXXSRC) $(CXXHDR)
    $(SHELL) -x $<

# Delete the object files.
clean:
    @echo " "
    $(RM) $(OBJS) $(DEPS)
    @echo " "

mrproper: clean
    $(RM) $(BINARYDIR)$(PROGNAME)
    @echo " "

# Rule for making the actual target
lines="=========="
Lines=$(lines)$(lines)$(lines)$(lines)$(lines)$(lines)$(lines)$(lines)
$(PROGNAME): $(OBJS) #$(CCOBJS)
    @mkdir -p $(BINARYDIR)
    @echo " "
    @echo $(Lines)$(Lines)
    @echo "Creating executable: $(BINARYDIR)$(PROGNAME)"
    @echo $(Lines)$(Lines)
    @echo " "
    $(CXX) $(CXXFLAGS) -o $(BINARYDIR)$@ $^ $(LDFLAGS)
    @echo " "
    @echo $(Lines)$(Lines)
    @echo "Created executable: $(BINARYDIR)$(PROGNAME)"
    @echo $(Lines)$(Lines)
    @echo " "

# Rules for object files from cpp files
$(OBJECTDIR)%.o: %.cpp
    @mkdir -p $(OBJECTDIR) # $(dir $@)
    @echo " "
    $(CXX) -o $@ -c $< $(CXXFLAGS)

# Make dependancy rules
$(DEPENDDIR)%.d: %.cpp
    @mkdir -p $(DEPENDDIR)
    $(CXX) -M -MG -MT $(OBJECTDIR)$*.o $(CXXFLAGS) $< > $@

# The compilation depends on this Makefile.
$(OBJS): Makefile

# Make everything
all:
    cd ..; $(MAKE) all


# Clean everything
cleanall:
    cd ..; $(MAKE) clean

# Properly clean everything
mrproperall:
    cd ..; $(MAKE) mrproper

# Properly clean & recompile
fresh:
    cd ..; $(MAKE) fresh

-include $(DEPS)

Answer 1

由于您正在使用-include $(DEPS)，所以正在构建它。

请参见Including Other Makefiles

如果在任何这些目录中都找不到包含的makefile，则警告消息已生成，但不是立即致命的错误;包含包含的makefile的处理继续。完成读取makefile文件后，make将尝试重新制作任何过期或不存在的请参阅如何重新制作Makefile。只有在尝试找到一种重新制作Makefile的方法并失败之后，将诊断出丢失的Makefile为致命错误。

然后继续说：

如果您想让make仅仅忽略一个不存在的makefile或   无法重制，没有错误消息，请使用-include指令   而不是包含，例如：-include filenames…

无论文件名（或其他任何文件名）没有错误（甚至没有警告），这一切都类似于include。   任何文件名的先决条件）不存在或不能为   重制。

诚然，这可能用不同的方式解释。我刚刚确认它确实确实尝试在-include行上重制具有明确重制规则的文件：

all:
        @echo building $@

foo.d :
        @echo building $@
        @touch $@

-include foo.d bar.d

哪个给：

 tmp> make all
 building foo.d
 building all

因此，这为如何解决问题留下了一个有趣的案例。对依赖文件使用单独的规则确实会增加编译时间-您现在将每个源文件解析两次-一次生成.d一次，一次进行编译。这个不好。我认为，将依赖性和.o规则结合起来是您的最大利益。然后使依赖于version.hpp的$(OBJS)的子集显式依赖于它，您应该会很好。

Answer 2

您应该使-include $(DEPS)行成为条件行-当MAKECMDGOALS仅包含“干净”目标时，将其从makefile中排除：

ifneq(,$(filter-out clean distclean clobber,$(MAKECMDGOALS)))
-include $(DEPS)
endif

顺便说一句，要提防cd成功-在其后使用&&-或者，如果在其他目录中调用Make，则只需使用其-C选项。

在不应该使用的makefile规则时

2 个答案: