[RFC PATCH v1] checkpatch: Handle FILE pointer type

[Mickaël Salaün]

When using a "FILE *" type, checkpatch considers this an error.  Fix
this by explicitly defining "FILE" as a common type.

This is useful for user space patches.

With this patch, we now get:
 static void a(FILE *const b)

 <E> <E> <_>WS( )
 <E> <E> <_>IDENT(static)
 <E> <V> <_>WS( )
 <E> <V> <_>DECLARE(void )
 <E> <T> <_>FUNC(a)
 <E> <V> <V>PAREN('(')
 <EV> <N> <_>DECLARE(FILE *const )
 <EV> <T> <_>IDENT(b)
 <EV> <V> <_>PAREN(')') -> V
 <E> <V> <_>WS(
)
32 > . static void a(FILE *const b)
32 > EEVVVVVVVTTTTTVNTTTTTTTTTTTTVVV
32 >  ______________________________

Another error may be throw when we use FIXTURE_{DATA,VARIANT}() structs,
as defined in kselftest_harness.h .  The commented
$typeKselftestHarnessTypedefs should fix it but such definition is
considered as a function instead, because of the closing parenthesis.
I'd like some help to fix this as well.

With $typeKselftestHarnessTypedefs added to $typeTypedefs, we get:
 static void c(const FIXTURE_VARIANT(d) *const e)

 <E> <E> <_>WS( )
 <E> <E> <_>IDENT(static)
 <E> <V> <_>WS( )
 <E> <V> <_>DECLARE(void )
 <E> <T> <_>FUNC(c)
 <E> <V> <V>PAREN('(')
 <EV> <N> <_>MODIFIER(const)
 <EV> <T> <_>WS( )
 <EV> <T> <_>FUNC(FIXTURE_VARIANT)
 <EV> <V> <V>PAREN('(')
 <EVV> <N> <_>IDENT(d)
 <EVV> <V> <_>PAREN(')') -> V
 <EV> <V> <_>WS( )
 <EV> <V> <_>OPV(*)
 <EV> <N> <_>MODIFIER(const)
 <EV> <T> <_>WS( )
 <EV> <T> <_>IDENT(e)
 <EV> <V> <_>PAREN(')') -> V
 <E> <V> <_>WS(
)
30 > . static void c(const FIXTURE_VARIANT(d) *const e)
30 > EEVVVVVVVTTTTTVNTTTTTTVVVVVVVVVVVVVVVNVVVNTTTTTTVVV
30 >  ________________________________________B_________

Cc: Andy Whitcroft <apw@xxxxxxxxxxxxx>
Cc: Dwaipayan Ray <dwaipayanray1@xxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Cc: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>
Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220901145948.1456353-1-mic@xxxxxxxxxxx
---
 scripts/checkpatch.pl | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 79e759aac543..016b47c35742 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -576,10 +576,17 @@ our $typeKernelTypedefs = qr{(?x:
 	(?:__)?(?:u|s|be|le)(?:8|16|32|64)|
 	atomic_t
 )};
+our $typeStdioTypedefs = qr{(?x:
+	FILE
+)};
+# our $typeKselftestHarnessTypedefs = qr{(?x:
+# 	FIXTURE_(?:DATA|VARIANT)\($Ident\)
+# )};
 our $typeTypedefs = qr{(?x:
 	$typeC99Typedefs\b|
 	$typeOtherOSTypedefs\b|
-	$typeKernelTypedefs\b
+	$typeKernelTypedefs\b|
+	$typeStdioTypedefs\b
 )};
 
 our $zero_initializer = qr{(?:(?:0[xX])?0+$Int_type?|NULL|false)\b};

base-commit: b90cb1053190353cc30f0fef0ef1f378ccc063c5
-- 
2.37.2