linux - 如何防止 Makefile 在链接之前清理对象(使用 -j 选项)

Question

我正在尝试学习如何使用 linux makefile。

我有以下两个文件:

生成文件.config

# Project Configurations

   # Project Name

   PROJECT_NAME               =           myapp

   # Project Version

   PROJECT_VERSION            =           0.1

   # Program or Shared Library

   IS_LIBRARY                 =           no

   # Source Files Directory

   SRC_DIRECTORY              =           src

   # Header Files Directory

   INC_DIRECTORY              =           inc

   # Library Header Files Directory

   LIB_DIRECTORY              =           lib

   # Build Output Directory   

   BIN_DIRECTORY              =           ../Executable

   # Installation Directory Exec

   INS_DIRECTORY               =           /usr/local/bin/
 
   # Installation Directory Headers
  
   INS_HEARERS_DIRECTORY       =           /usr/local/include/
 
   # Installation Directory SO      

   INS_SO_DIRECTORY            =           /usr/local/lib/

   # C Flags

   CFLAGS                     =           -O3 -D_GNU_SOURCE -Wfatal-errors
  
   # C++ Flags

   CXXFLAGS                   =           $(CFLAGS)
  
   # Linker Flags

   LDFLAGS                    =           $(shell dpkg-buildflags --get LDFLAGS)
  
   # Linker Libraries

   LDLIBS                     =           -fno-inline 

   # Debug Yes / No

   DEBUG                      =           yes

   # C Compiler

   CC                         =           gcc

   # C++ Compiler

   CXX                        =           g++

生成文件

$(info  Starting building process)

# include configurations

include makefile.conf

$(info  - Makefile.conf loaded)

# find project files

H_FILES   :=    $(shell find -L ./ -name '*.h' -exec dirname {} \; | sed 's/ /\\ /g' | uniq)

C_FILES   :=    $(shell find ./ -name '*.c' -type f | sed 's/ /\\ /g' | uniq)

CXX_FILES :=    $(shell find ./ -name '*.cpp' -type f | sed 's/ /\\ /g' | uniq)

O_FILES   :=    $(C_FILES:.c=.o)

O_FILES   +=    $(CXX_FILES:.cpp=.o)

H_FILES   :=    $(notdir  $(H_FILES))

C_FILES   :=    $(notdir  $(C_FILES))

CXX_FILES :=    $(notdir  $(CXX_FILES))

INCLUDES  :=    $(H_FILES:%=-I%)

$(info  - Project Files Loaded)


ifeq ($(DEBUG),yes)

   $(info  - Debug flag added [makefile.conf DEBUG = yes])

   CFLAGS := -g3 $(CFLAGS)

endif


ifeq ($(IS_LIBRARY),yes)

   $(info  - Set Parameters for Shared Library build process)

   ALL_PARAMETERS = lib$(PROJECT_NAME).so.$(PROJECT_VERSION) clean

   ALL_TYPE = lib$(PROJECT_NAME).so.$(PROJECT_VERSION): $(O_FILES)

   LIBFLAGS = -shared -Wl,-soname,lib$(PROJECT_NAME).so

   CFLAGS :=  -fPIC $(CFLAGS)

   CXXFLAGS := -fPIC $(CXXFLAGS)

else

   $(info  - Set Parameters for Application build process)

   ALL_PARAMETERS = $(PROJECT_NAME) clean

   ALL_TYPE = $(PROJECT_NAME): $(O_FILES)

   LIBFLAGS =

endif

# Build Process

all: $(ALL_PARAMETERS)

$(ALL_TYPE)
    @echo -  [OUTPUT][CXX] $@ @[$(BIN_DIRECTORY)]
    @$(CXX) $(CFLAGS) $(INCLUDES) $(LDFLAGS) $(LIBFLAGS) -o $(BIN_DIRECTORY)/$@ $^ $(LDLIBS)

%.o: %.c
    @echo -  [CC] $@
    @$(CC) $(CFLAGS) -c $(INCLUDES) -o $@ $< $(LFLAGS)

%.o: %.cpp
    @echo -  [CXX] $@
    @$(CXX) $(CXXFLAGS) -c $(INCLUDES) -o $@ $< $(LFLAGS)

# Clear Objects

clean:
    $(info  - Remove all .o [object] files)
    @find . -name \*.o -type f -delete

# Clear Objects & Executables 

cleanall:   
    $(info  - Remove all .o [object] files)
    @find . -name \*.o -type f -delete
    $(info  - Remove all files in $(BIN_DIRECTORY))
    @find $(BIN_DIRECTORY) -name \*.* -type f -delete

# Install Project 

install:
    @cp -r $(BIN_DIRECTORY)/lib$(PROJECT_NAME).so.$(PROJECT_VERSION) $(INS_SO_DIRECTORY)
    @cp -r $(LIB_DIRECTORY)/* $(INS_HEARERS_DIRECTORY)
    @ln -s $(INS_SO_DIRECTORY)/lib$(PROJECT_NAME).so.$(PROJECT_VERSION) $(INS_SO_DIRECTORY)/lib$(PROJECT_NAME).so
    @ldconfig
    $(info  - Installation completed)

# Uninstall Project 

uninstall:
    @rm $(INS_SO_DIRECTORY)/lib$(PROJECT_NAME).so
    @rm $(INS_SO_DIRECTORY)/lib$(PROJECT_NAME).so.*.*
    @rm $(INS_HEARERS_DIRECTORY)/$(PROJECT_NAME).h
    @ldconfig
    $(info  - Uninstallation completed)

一切都很完美......至少对于我使用它的目的而言......但是当我尝试使用 -j 选项(例如)执行 makefile 时

$ make -j4

该过程在链接它们之前清理对象 (.o)。

iikem@isca-lab:Source Code$ make -j4
Starting building process
- Makefile.conf loaded
- Project Files Loaded
- Debug flag added [makefile.conf DEBUG = yes]
- Set Parameters for Shared Library build process
- [CXX] src/isca-streamer.o
- [CXX] src/isca-streamer-pause.o
- [CXX] src/isca-streamer-thread-image.o
- [CXX] src/isca-streamer-initialize.o
- [CXX] src/isca-streamer-start.o
- [CXX] src/isca-streamer-stop.o
- [CXX] src/isca-streamer-thread-socket.o
- [CXX] src/isca-streamer-clear.o
- Remove all .o [object] files
- [CXX] src/isca-streamer-settings.o
- [OUTPUT][CXX] libisca-streamer.so.0.1 @[../Executable]
g++: error: src/isca-streamer.o: No such file or directory
g++: error: src/isca-streamer-initialize.o: No such file or directory
g++: error: src/isca-streamer-thread-image.o: No such file or directory
g++: error: src/isca-streamer-pause.o: No such file or directory
g++: error: src/isca-streamer-start.o: No such file or directory
g++: error: src/isca-streamer-stop.o: No such file or directory
Makefile:71: recipe for target 'libisca-streamer.so.0.1' failed
make: *** [libisca-streamer.so.0.1] Error 1

我该如何解决这个问题？ (防止清理对象步骤在链接步骤之前执行)

Answer 1

如果您使用 -j，则不能将 clean 添加为 all 目标的先决条件，因为它将并行运行使用链接器删除文件比链接它们要快得多。

因此，您必须从 ALL_PARAMETERS 变量中删除 clean 目标，这样您就不会再删除链接行中间的对象。

我不知道你为什么要在每次运行后删除所有对象:如果你每次都要从头开始重建一切，你甚至根本不需要 make 或 makefile:只需创建一个 shell 脚本。使用 makefile 的全部意义在于避免重建项目中未更改的部分。

但是，如果您真的想这样做，那么最简单的方法可能是使用递归 make；例如:

all: $(ALL_PARAMETERS)
        $(MAKE) clean

只会在 all 的所有先决条件完全构建之后才进行清理，即使您使用 -j 运行也是如此。