From 715ca322b4f23a2b15adb34d0d829ae34c04dede Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Mon, 28 May 2018 18:21:53 +0900
Subject: [PATCH] kconfig: add 'info', 'warning-if', and 'error-if' built-in
 functions

Syntax:
  $(info,<text>)
  $(warning-if,<condition>,<text>)
  $(error-if,<condition>,<text)

The 'info' function prints a message to stdout as in Make.

The 'warning-if' and 'error-if' are similar to 'warning' and 'error'
in Make, but take the condition parameter.  They are effective only
when the <condition> part is y.

Kconfig does not implement the lazy expansion as used in the 'if'
'and, 'or' functions in Make.  In other words, Kconfig does not
support conditional expansion.  The unconditional 'error' function
would always terminate the parsing, hence would be useless in Kconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
---
 config/preprocess.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/config/preprocess.c b/config/preprocess.c
index 56aa1f0..5ee58ee 100644
--- a/config/preprocess.c
+++ b/config/preprocess.c
@@ -106,6 +106,21 @@ struct function {
 	char *(*func)(int argc, char *argv[]);
 };
 
+static char *do_error_if(int argc, char *argv[])
+{
+	if (!strcmp(argv[0], "y"))
+		pperror("%s", argv[1]);
+
+	return NULL;
+}
+
+static char *do_info(int argc, char *argv[])
+{
+	printf("%s\n", argv[0]);
+
+	return xstrdup("");
+}
+
 static char *do_shell(int argc, char *argv[])
 {
 	FILE *p;
@@ -146,9 +161,21 @@ static char *do_shell(int argc, char *argv[])
 	return xstrdup(buf);
 }
 
+static char *do_warning_if(int argc, char *argv[])
+{
+	if (!strcmp(argv[0], "y"))
+		fprintf(stderr, "%s:%d: %s\n",
+			current_file->name, yylineno, argv[1]);
+
+	return xstrdup("");
+}
+
 static const struct function function_table[] = {
 	/* Name		MIN	MAX	Function */
+	{ "error-if",	2,	2,	do_error_if },
+	{ "info",	1,	1,	do_info },
 	{ "shell",	1,	1,	do_shell },
+	{ "warning-if",	2,	2,	do_warning_if },
 };
 
 #define FUNCTION_MAX_ARGS		16
-- 
2.31.1