[BUG] checkpatch.pl: false positive: space prohibited before open square bracket

[BUG] checkpatch.pl: false positive: space prohibited before open square bracket

[Heinrich Schuchardt]

This patch leads to errors "space prohibited before open square
bracket '['" for the asm statement.

In the inline assembler statement the bracket is not used for an index.
Adding a space after a colon or a comma should be allowable.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
 foo.c | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 foo.c

diff --git a/foo.c b/foo.c
new file mode 100644
index 000000000000..7f0ed923f997
--- /dev/null
+++ b/foo.c
@@ -0,0 +1,11 @@
+static inline u32 deref(u32 *addr)
+{
+	int ret;
+
+	asm(
+		"ldr %[out], [%[in]]\n\t"
+		: [out] "=r" (ret)
+		: [in] "r" (addr)
+	);
+	return ret;
+}
-- 
2.16.3

[PATCH 1/1] checkpatch: allow space between colon and bracket

[Heinrich Schuchardt]

Allow a space between a colon and subsequent opening bracket.
This sequence may occur in inline assembler statements like

	asm(
		"ldr %[out], [%[in]]\n\t"
		: [out] "=r" (ret)
		: [in] "r" (addr)
	);

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
 scripts/checkpatch.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d2464002bb40..2cbab86e6d4c 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4083,7 +4083,7 @@ sub process {
 			my ($where, $prefix) = ($-[1], $1);
 			if ($prefix !~ /$Type\s+$/ &&
 			    ($where != 0 || $prefix !~ /^.\s+$/) &&
-			    $prefix !~ /[{,]\s+$/) {
+			    $prefix !~ /[{,:]\s+$/) {
 				if (ERROR("BRACKET_SPACE",
 					  "space prohibited before open square bracket '['\n" . $herecurr) &&
 				    $fix) {
-- 
2.16.3

Re: [PATCH 1/1] checkpatch: allow space between colon and bracket

[Joe Perches]

On Tue, 2018-04-03 at 21:16 +0200, Heinrich Schuchardt wrote:
> Allow a space between a colon and subsequent opening bracket.
> This sequence may occur in inline assembler statements like
> 
> 	asm(
> 		"ldr %[out], [%[in]]\n\t"
> 		: [out] "=r" (ret)
> 		: [in] "r" (addr)
> 	);
> 
> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

I can't think of a valid c90 sequence that has a colon
before a bracket so

Acked-by: Joe Perches <joe@perches.com>

> ---
>  scripts/checkpatch.pl | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index d2464002bb40..2cbab86e6d4c 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -4083,7 +4083,7 @@ sub process {
>  			my ($where, $prefix) = ($-[1], $1);
>  			if ($prefix !~ /$Type\s+$/ &&
>  			    ($where != 0 || $prefix !~ /^.\s+$/) &&
> -			    $prefix !~ /[{,]\s+$/) {
> +			    $prefix !~ /[{,:]\s+$/) {
>  				if (ERROR("BRACKET_SPACE",
>  					  "space prohibited before open square bracket '['\n" . $herecurr) &&
>  				    $fix) {