如何在 kbuild makefile 中运行 perl

Question

我正在尝试向当前版本添加新功能。要编译，我已将 obj-y += mynewfeature.c 添加到同一目录中的 makefile 中。但我仍然需要使用同一目录中的 perl 脚本生成或更新现有的头文件。我无法处理的问题是如何从 kbuild 文件中调用这个 perl 脚本。似乎 makefile 无法找到 perl 脚本的正确路径。那么我应该在 kbuild 文件的顶部添加什么来调用这个 perl 脚本文件

谢谢

dir
 |- mynewfeature.c
 |- generator.pl
 |- some_template //perl script will read this file and generate a header file
 |- Makefile

Makefile:
code_to_call_perl_script // how to write this line
obj-y += mynewfeature.o

我试过 Ian 的代码，perl 脚本甚至没有执行。那么有没有办法强制执行 perl？

Answer 1

Makefile 规则应该是这样的：

obj-y += mynewfeature.o

# Add dependency: mynewfeature.o depends on generated header mynewheader.h.
# Note: Generated sources go in $(obj).
$(obj)/mynewfeature.o: $(obj)/mynewheader.h

# Add rule to generate the header file mynewheader.h.
# It depends on the script and the template file.
# Note: Generated sources go in $(obj).
$(obj)/mynewheader.h: $(src)/generator.pl $(src)/some_template
    # (I don't know the exact command you use, but here is an example)
    $(PERL) -s $(src)/generator.pl $(src)/some_template > $@

# Allow generated header file to be cleaned by "make clean".
clean-files := mynewheader.h

参考：Special Rules in Linux Kernel Makefiles in Kernel Build System in The Linux Kernel documentation。

具体例子见drivers/scsi/Makefile中“53c700_d.h”的生成。