如何在Makefile目标中使用Bash语法？

我经常发现Bash语法非常有用,例如像diff <(sort file1) <(sort file2).中的进程替换.

是否可以在Makefile中使用此类Bash命令？我在考虑这样的事情:

file-differences:
    diff <(sort file1) <(sort file2) > $@

在我的GNU Make 3.80中,这会产生错误,因为它使用shell而不是bash执行命令.

从GNU Make文档中,

5.3.1 Choosing the Shell
------------------------

The program used as the shell is taken from the variable `SHELL'.  If
this variable is not set in your makefile, the program `/bin/sh' is
used as the shell.

all: a b

a:
    @echo "a is $$0"

b: SHELL:=/bin/bash   # HERE: this is setting the shell for b only
b:
    @echo "b is $$0"

a is /bin/sh
b is /bin/bash

bash -c "diff <(sort file1) <(sort file2) > $@"