GNU make似乎忽略了中间文件的非终端匹配规则 [英] GNU make seems to ignore non-terminal match-anything rules for intermediate files
问题描述
我在目录中有以下文件:
I have the following files in a directory:
FP01.c:
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
long double ld = 0.1L; // long double constant (L or l suffix)
scanf("%Lf", &ld);
return 0;
}
makefile:
MAKEFLAGS += -rR
# the default target
.PHONY: all
all: FP01.elf
%.elf: %
cp $< $@
# prevents non-terminal match-anything rules from matching target '%.c'
# see section 10.5.5 of GNU make manual
%.c:
# a non-terminal match-anything rule
%: %.c
gcc -Wall -g $< -o $@
如果FP01
不存在,则运行make
会给出以下输出:
If FP01
does not exist, running make
gives the following output:
make: *** No rule to make target 'FP01.elf', needed by 'all'. Stop.
但是,如果我在make
之前运行以下命令,那么一切都会按预期进行:
However, if I run the following commands before make
, then everything works as expected:
$ touch FP01
$ touch FP01.c
$ make
gcc -Wall -g FP01.c -o FP01
cp FP01 FP01.elf
我丢失了某些东西还是GNU make中存在错误?
Am I missing something or there is a bug in GNU make?
make --version
给出以下输出:
GNU make 4.1
Built for i686-pc-linux-gnu
Copyright (C) 1988-2014 Free Software Fundation, Inc.
License GPLv3+: ...
...
似乎使任何内容匹配的规则终端都可以解决该问题,但是我想尽可能使用内置规则来生成FP01,不幸的是它不是终端终端.
It seems that making match-anything rule terminal somehow fixes the problem, but I want to use built-in rule to generate FP01 if possible and unfortunately it is non-terminal.
另一件事是,我认为非终止规则应该起作用,因此使用终止规则并不能真正解决问题,因为我仍然不知道该错误是在make还是在我的心理makefile解析器"中. /p>
Another thing is that I believe that non-terminal rule should work so using terminal rule doesn't actually solve the problem as I still don't know whether the bug is in make or in my "mental makefile parser".
推荐答案
我认为您应该在% : %.c
规则上使用::
,因为您实际上希望将其作为任何内容的最终匹配规则(因为您不希望这样做)需要构建.c
文件):
I think you should use ::
on the % : %.c
rule because you actually want that to be a terminal match-anything rule (since you don't need the .c
file to be built):
MAKEFLAGS += -rR
.PHONY: all
all: FP01.elf
%.elf: % ; cp $< $@
% :: %.c ; gcc -Wall -g $< -o $@
请注意,这里我将;
表单用于配方,因为它更容易复制和粘贴,因为无需担心制表符.
Note that I used the ;
form for the recipes here because it's easier to copy and paste because no need to worry about tabs.
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