When adding a function declaration in a .c file without extern
keywork decoration, checkpatch.pl will report *externs should be
avoided in .c files* false error. This patch fixes the bug.

Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
---
 scripts/checkpatch.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 3c0a28e..c12bc4c 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2534,7 +2534,7 @@ sub process {
 
 # check for new externs in .c files.
 		if ($realfile =~ /\.c$/ && defined $stat &&
-		    $stat =~ /^.\s*(?:extern\s+)?$Type\s+($Ident)(\s*)\(/s)
+		    $stat =~ /^.\s*(?:extern\s+)$Type\s+($Ident)(\s*)\(/s)
 		{
 			my $function_name = $1;
 			my $paren_space = $2;
-- 
2.7.4

On 10 October 2017 at 08:54, Jiang Biao <jiang.biao2@zte.com.cn> wrote:
> When adding a function declaration in a .c file without extern
> keywork decoration, checkpatch.pl will report *externs should be
> avoided in .c files* false error. This patch fixes the bug.

I don't think this is a bug. "extern int foo(void);" and
"int foo(void);" have the same effect: they declare a function
prototype that can be called from outside the file.
We don't want to permit that in QEMU. Either:
 (1) the function is for use only within this file: the
 declaration should be "static int foo(void);"
 (2) the function is for use by other files too: the
 declaration should be in a header file, not a .c file,
 so the other files can use it

Do you have an example of code where this warning is a problem?

thanks
-- PMM

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