Kconfig

 1# SPDX-License-Identifier: GPL-2.0
 2
 3# 'info' prints the argument to stdout.
 4$(info,hello world 0)
 5
 6# 'warning-if', if the first argument is y, sends the second argument to stderr,
 7# and the message is prefixed with the current file name and line number.
 8$(warning-if,y,hello world 1)
 9
10# 'error-if' is similar, but it terminates the parsing immediately.
11# The following is just no-op since the first argument is not y.
12$(error-if,n,this should not be printed)
13
14# Shorthand
15warning = $(warning-if,y,$(1))
16
17# 'shell' executes a command, and returns its stdout.
18$(warning,$(shell,echo hello world 3))
19
20# Every newline in the output is replaced with a space,
21# but any trailing newlines are deleted.
22$(warning,$(shell,printf 'hello\nworld\n\n4\n\n\n'))
23
24# 'filename' is expanded to the currently parsed file name,
25# 'lineno' to the line number.
26$(warning,filename=$(filename))
27$(warning,lineno=$(lineno))