美好的一天,我正在编写自己的makefile文章,我在这里找到了教程:
http://www.cs.colby.edu/maxwell/courses/tutorials/maketutor/
我知道这个教程适用于C makefile,但我相信C和C ++之间的相似之处意味着makefile的功能几乎没有区别(例如,我使用的是g ++而不是gcc)。我希望我在这一点上的假设不是一个因素,因为之前的4个教程中的每一个似乎都运行得很好。
在教程中运行Makefile 5时,我收到有关从.cpp文件构造目标文件的错误:
make: *** No rule to make target '%.cpp', needed by 'obj'. Stop.
我似乎无法弄清楚为什么会发生这种情况,非常令人困惑和沮丧,因为我觉得这不应该发生。我在下面提供了我的完整Makefile,非常感谢任何帮助:
# Example Makefile
# ----------------
# Please remember to turn off the vim option: 'expandtab' so that tabs are
# actually displayed as tabs (do so like this - :set noexpandtab )
#
# This file specifies dependencies, which means that the two c++ files must
# be compiled before the executable is built
# ------------------
# Makefile Constants
# ------------------
# Directory constants
IDIR =../include # Specifies location of include directory
ODIR =obj # Specifies location of object directory
LDIR =../lib # Specifies location of library directory
LIBS=-lm # ?
# Options constants
CC=g++ # Specifies the specific C compiler to use, g++ specifies C++ compiler
CFLAGS=-I$(IDIR) # List of flags to pass to compilation command
# Dependency Constants
DEP_FILES=helloMake.h # Specifies dependency files
DEPS=$(patsubst %,$(IDIR)/%,$(DEP_FILES)) # Specifies path to dependencies and dependency files
# Object constants
OBJ_FILES=helloMake.o helloFunc.o # Specify object files
OBJ=$(patsubst %,$(ODIR)/%,$(OBJ_FILES)) # Specifies path to objects and object files
# -----------
# Compilation
# -----------
# Specify rules to make object files
$(ODIR)/%.o: %.cpp $(DEPS) # Specifies that .o files depend on the .cpp version of the file and the .h files included in the DEPS macro
$(CC) -c -o $@ $< $(CFLAGS) # The -c flag says to generate the object file, the -o $@ says to put the output of the compilation in the
# file named on the left side of the : the $< is the first item in the dependencies list
# Specify rules to make target executable
helloMake: $(OBJ) # Target : Dependencies
$(CC) -o $@ $^ $(CFLAGS) $(LIBS) # This is the actual compilation command
.PHONY: clean # Prevent the make command from attempting to do something with a file named 'clean'
# Specify rules to clean the object files
clean:
rm -f $(ODIR)/*.o *~ core $(INCDIR)/*~ # Removes all compiled object files
答案 0 :(得分:1)
这&#34;简单&#34;不幸的是,教程会促进不良做法。
基本上,您首先需要一个正确的C Makefile:
# Specify the final target name
EXE := helloMake
# Specify the source files
# Effectively list all source files in the current directory
SRC := $(wildcard *.c)
# From the source file list, get the corresponding object file list
# This is a clearer syntax for $(patsubst %.c,%.o,$(SRC))
OBJ := $(SRC:.c=.o)
# From the object file list, get the dependency file list to handle automatic
# recompilation when a header file is modified
DEP := $(OBJ:.o=.d)
# Specify preprocessor flags (this is a built-in variable)
CPPFLAGS := -I../include
# Required flags to enable the automatic dependency generation by the compiler
CPPFLAGS += -MMD -MP
# Specify compiler flags (this is a built-in variable)
# Here some basic warning flags
CFLAGS := -Wall -W -pedantic
# Specify linker flags (this is a built-in variable)
LDFLAGS := -L../lib
# Specify linker libraries (this is a built-in variable)
# m is the maths library
LDLIBS := -lm
# Tell make that these target are not real files
.PHONY: all clean
# Now the standard primary rule
all: $(EXE)
# How do we make $(EXE) ? Remember the recipe describe the linking phase
$(EXE): $(OBJ)
$(CC) $(LDFLAGS) $^ $(LDLIBS) -o $@
# Let's clean up the mess
clean:
$(RM) $(EXE) $(OBJ) $(DEP)
# Don't forget to include the dependency files to let make know when to recompile
-include $(DEP)
然后你需要知道C Makefile和C ++ Makefile之间的区别:
$(CXX)
代替$(CC)
,$(CXXFLAGS)
代替$(CFLAGS)
,.cpp
代替.c
。你已经完成了。
# Specify the final target name
EXE := helloMake
# Specify the source files
# Effectively list all source files in the current directory
SRC := $(wildcard *.cpp)
# From the source file list, get the corresponding object file list
# This is a clearer syntax for $(patsubst %.cpp,%.o,$(SRC))
OBJ := $(SRC:.cpp=.o)
# From the object file list, get the dependency file list to handle automatic
# recompilation when a header file is modified
DEP := $(OBJ:.o=.d)
# Specify preprocessor flags (this is a built-in variable)
CPPFLAGS := -I../include
# Required flags to enable the automatic dependency generation by the compiler
CPPFLAGS += -MMD -MP
# Specify compiler flags (this is a built-in variable)
# Here some basic warning flags
CXXFLAGS := -Wall -W -pedantic
# Specify linker flags (this is a built-in variable)
LDFLAGS := -L../lib
# Specify linker libraries (this is a built-in variable)
# m is the maths library
LDLIBS := -lm
# Tell make that these target are not real files
.PHONY: all clean
# Now the standard primary rule
all: $(EXE)
# How do we make $(EXE) ? Remember the recipe describe the linking phase
$(EXE): $(OBJ)
$(CXX) $(LDFLAGS) $^ $(LDLIBS) -o $@
# Let's clean up the mess
clean:
$(RM) $(EXE) $(OBJ) $(DEP)
# Don't forget to include the dependency files to let make know when to recompile
-include $(DEP)
编辑:为了能够重新定位构建文件(.o
和.d
文件),您需要进行一些调整:
# Specify the final target name
EXE := helloMake
# Specify the source files
# Effectively list all source files in the current directory
SRC := $(wildcard *.cpp)
# Specify where to put the build temporary files
BLD := obj
# From the source file list, get the corresponding object file list
# This is a clearer syntax for $(patsubst %.cpp,$(BLD)/%.o,$(SRC))
OBJ := $(SRC:%.cpp=$(BLD)/%.o)
# From the object file list, get the dependency file list to handle automatic
# recompilation when a header file is modified
DEP := $(OBJ:.o=.d)
# Specify preprocessor flags (this is a built-in variable)
CPPFLAGS := -I../include
# Required flags to enable the automatic dependency generation by the compiler
CPPFLAGS += -MMD -MP
# Specify compiler flags (this is a built-in variable)
# Here some basic warning flags
CXXFLAGS := -Wall -W -pedantic
# Specify linker flags (this is a built-in variable)
LDFLAGS := -L../lib
# Specify linker libraries (this is a built-in variable)
# m is the maths library
LDLIBS := -lm
# Tell make that these target are not real files
.PHONY: all clean
# Now the standard primary rule
all: $(EXE)
# How do we make $(EXE) ? Remember the recipe describe the linking phase
$(EXE): $(OBJ)
$(CXX) $(LDFLAGS) $^ $(LDLIBS) -o $@
# The build directory is custom so we need to tell make how to do it
# The build directory must exist before trying to compile
$(BLD)/%.o: %.cpp | $(BLD)
$(CXX) $(CPPFLAGS) $(CXXFLAGS) -o $@ -c $<
# Simple rule to create the build directory if needed
$(BLD):
mkdir $@
# Let's clean up the mess, we can just remove the build directory alonside the executable
clean:
$(RM) -r $(BLD) $(EXE)
# Don't forget to include the dependency files to let make know when to recompile
-include $(DEP)
答案 1 :(得分:0)
%
语法不是标准make
,而是由例如GNU make
提供的扩展功能。 autotools
(否则,您必须为每个源文件编写特定规则,或者使用生成巨大 Makefile
的内容(但可移植){{1} } S)。因此,您应该确保使用支持此功能的make
实用程序。如果那不是问题,您确定当前目录中确实有*.cpp
个文件吗?