Makefile说变量是空的,但它不是

Makefile says that variable is empty but it's not

本文关键字:变量 Makefile      更新时间:2023-10-16

我正在尝试创建具有以下内容的makefile:

$(CXX)=g++
$(SRC)=../src
$(INCL)=../include
all: cpu ram temperature swap statusshooter
    $(CXX) main.cpp cpu.o ram.o temperature.o swap.o statusshooter.o -o main.o -I$(INCL) -Ofast -Wall -lyaml-cpp -lglog -lpqxx -lpq
cpu:
    $(CXX) -c $(SRC)/CCpu.cpp -o cpu.o -Ofast -Wall 
ram:
    $(CXX) -c $(SRC)/CRam.cpp -o ram.o -Ofast -Wall 
temperature:
    $(CXX) -c $(SRC)/CTemperature.cpp -o temperature.o -Ofast -Wall
swap:
    $(CXX) -c $(SRC)/CSwap.cpp -o swap.o -Ofast -Wall  
statusshooter:
    $(CXX) -c $(SRC)/CStatusShooter.cpp -o statusshooter.o -Ofast -Wall  

使用执行该生成文件:make CXX=g++-4.7抛出以下错误:

makefile:2: *** empty variable name.  Stop.

如何解决此问题?

语法$(CXX)用于评估make变量,而不是分配给它

CXX  = g++
SRC  = ../src
INCL = ../include
[...]

要为变量赋值,请写var=...,而不是$var=...,因此,在您的情况下,CXX=g++