接上文,修改gcc 的-std标准后,.depend文件处理仍然出现了错误:
五、错误:make中命令报错(sed找不到需要的文件)
错误告警如下:
1 make -C examples/api all 2 make[1]: 进入目录“/u-boot-2010.09/u-boot-2010.09/examples/api” 3 sed -i ‘s/d:\//\/cygdrive\/d\//g‘ .depend 4 sed:无法读取 .depend:No such file or directory 5 make[1]: *** 没有规则可以创建“all”需要的目标“.depend”。 停止。 6 make[1]: 离开目录“/u-boot-2010.09/u-boot-2010.09/examples/api” 7 Makefile:378: recipe for target `examples/api‘ failed 8 make: *** [examples/api] Error 2
1、分析
错误提示比较明显,是 examples/api中,没有.depend规则的产生。
而之前 sed命令,是需要.depend文件存在的。
2、解决思路1:首先会想到if...else来实现
又有两种思路,一种是make自身带的,一种是shell工具。该部分单独讨论,不再本文描述。(大家可以自己尝试)
3、解决思路2:先建立一个空.depend文件
原始代码如下:
1 $(obj).depend: $(src)Makefile $(TOPDIR)/config.mk $(SRCS) $(HOSTSRCS) 2 @rm -f $@ 3 @for f in $(SRCS); do 4 g=`basename $$f | sed -e ‘s/\(.*\)\.\w/\1.o/‘`; 5 $(CC) -M $(CPPFLAGS) -MQ $(obj)$$g $$f >> $@ ; 6 done 7 @for f in $(HOSTSRCS); do 8 g=`basename $$f | sed -e ‘s/\(.*\)\.\w/\1.o/‘`; 9 $(HOSTCC) -M $(HOSTCPPFLAGS) -MQ $(obj)$$g $$f >> $@ ; 10 done 11 sed -i ‘s/d:\//\/cygdrive\/d\//g‘ $@
只需要在第2行后,增加 touch $@ 即可。
4、解决思路3:利用make的忽视错误规则
make 对其规则中调用的外部程序返回的错误可选的应对。
To ignore errors in a recipe line, write a ‘-’ at the beginning of the line’s text
(after theinitial tab). The ‘-’ is discarded before the line is passed to the shell for execution.
可知,如果将“-”放置到调用命令之前,就可以忽视外部命令的错误。
可以利用: - sed -i ‘s/d:\//\/cygdrive\/d\//g‘ $@
来忽视相关错误。
扩展:对于include这个内部命令也可以这样用,但还有一种别名:sinclude (相当于 -include)。
前文 autoconf.mk.dep 格式错误时,涉及到sinclude。其主要是解决引用找不到文件等错误,如果文件内部错误,sinclude也无法避免。
详细信息参见:https://www.gnu.org/software/make/manual/make.html#Errors
5、后记
make错误信息含义:
https://www.gnu.org/software/make/manual/make.html#Error-Messages
之前,make的错误为:multiple target patterns. Stop.
1 ‘missing target pattern. Stop.’ 2 ‘multiple target patterns. Stop.’ 3 ‘target pattern contains no ‘%’. Stop.’ 4 ‘mixed implicit and static pattern rules. Stop.’ 5 These are generated for malformed static pattern rules. 6 The first means there’s no pattern in the target section of the rule; 7 the second means there are multiple patterns in the target section; 8 the third means the target doesn’t contain a pattern character (%); 9 and the fourth means that all three parts of the static pattern rule 10 contain pattern characters (%)–only the first two parts should. 11 If you see these errors and you aren’t trying to create a static pattern rule, 12 check the value of any variables in your target and prerequisite lists 13 to be sure they do not contain colons.
===【未完待续】===