有沒有辦法強制重建目標（make -B）而不重建它的依賴關係？

Question

GNU Make有-B選項，強制make忽略現有目標。它允許重建目標，但它也重建目標的所有依賴樹。我不知道有沒有辦法強制重建目標而不重建它的依賴關係（使用GNU Make選項，Makefile中的設置，兼容make的軟件等）？

插圖的問題：

$ mkdir test; cd test 
$ unexpand -t4 >Makefile <<EOF 
huge: 
    @echo "rebuilding huge"; date >huge 
small: huge 
    @echo "rebuilding small"; sh -c 'cat huge; date' >small 
EOF 
$ make small 
rebuilding huge 
rebuilding small 
$ ls 
huge Makefile small 
$ make small 
make: 'small' is up to date. 
$ make -B small 
rebuilding huge # how to get rid of this line? 
rebuilding small 
$ make --version | head -n3 
GNU Make 4.0 
Built for x86_64-pc-linux-gnu 
Copyright (C) 1988-2013 Free Software Foundation, Inc. 

當然一個可以rm small; make small，但有一個內置的方式？

Answer 1

一種方法是使用-o選項，你不希望所有的目標，以重拍：

-o FILE, --old-file=FILE, --assume-old=FILE 
     Consider FILE to be very old and don't remake it. 

編輯

我想你誤讀的文檔爲-B;它說：

-B, --always-make 
     Unconditionally make all targets. 

注意，所有目標這裏; huge肯定是一個目標，所以如果你使用-B它將被重拍。

但是，我也誤解了你的問題。我以爲你想重建small而不重建huge即使huge是新的，但你試圖讓small重建，儘管huge已沒有改變，對吧？

你絕對不想使用-B。這個選項根本不是你想要的。

通常人們會做，通過刪除small：

rm -f small 
make small 

這可能是有用的，迫使一個給定的目標重新創建一個選項，但該選項不存在。

您可以使用-W huge，但這又意味着您需要知道必備條件的名稱，而不僅僅是要構建的目標。在相當惡劣的黑客

Answer 2

文件：

huge: 
    @echo "rebuilding huge"; date >huge 

small: $(if $(filter just,${MAKECMDGOALS}),huge) 
    @echo "rebuilding small"; sh -c 'cat huge; date' >small 

.PHONY: just 
just: ; 

現在你可以

$ make -B just small 

Answer 3

這能否幫助：

touch huge; make small 

？

Answer 4

好了，到目前爲止我用這部分解決方案：

$ cat >~/bin/remake <<'EOF' 
#!/bin/sh 
# http://stackoverflow.com/questions/42139227 
for f in "$@"; do 
    if [ -f "$f" ]; then 
    # Make the file very old; it's safer than removing. 
    touch --date=@0 "$f" 
    fi 
done 
make "$@" 
EOF 
$ chmod u+x ~/bin/remake 
$ # PATH="$HOME/bin:$PATH" in .bashrc 
$ remake --debug=b small 
GNU Make 4.0 
Built for x86_64-pc-linux-gnu 
Copyright (C) 1988-2013 Free Software Foundation, Inc. 
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> 
This is free software: you are free to change and redistribute it. 
There is NO WARRANTY, to the extent permitted by law. 
Reading makefiles... 
Updating goal targets.... 
Prerequisite 'huge' is newer than target 'small'. 
Must remake target 'small'. 
rebuilding small 

Answer 5

我用的是這樣的：

remake() 
{ 
    for f in "$@" 
    do 
    [ -f "$f" ] && rm -f "$f" 
    done 
    make "$@" 
}