From 1d6272e6fe43bc45c7ee58170d91d7242a71296b 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>
---
 scripts/kconfig/preprocess.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c
index 56aa1f0bad04..5ee58eeb9a7d 100644
--- a/scripts/kconfig/preprocess.c
+++ b/scripts/kconfig/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