[PATCH] linux-user: fix implicit conversion from enumeration type error

[PATCH] linux-user: fix implicit conversion from enumeration type error

[Laurent Vivier]

MK_ARRAY(type,size) is used to fill the field_types buffer, and if the
"size" parameter is an enum type, clang [-Werror,-Wenum-conversion] reports
an error when it is assigned to field_types which is also an enum, argtypes.

To avoid that, convert "size" to "int" in MK_ARRAY(). "int" is the type
used for the size evaluation in thunk_type_size().

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 include/exec/user/thunk.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/exec/user/thunk.h b/include/exec/user/thunk.h
index a5bbb2c73331..b798fcb69cf4 100644
--- a/include/exec/user/thunk.h
+++ b/include/exec/user/thunk.h
@@ -42,7 +42,7 @@ typedef enum argtype {
 } argtype;
 
 #define MK_PTR(type) TYPE_PTR, type
-#define MK_ARRAY(type, size) TYPE_ARRAY, size, type
+#define MK_ARRAY(type, size) TYPE_ARRAY, (int)size, type
 #define MK_STRUCT(id) TYPE_STRUCT, id
 
 #define THUNK_TARGET 0
-- 
2.26.2

Re: [PATCH] linux-user: fix implicit conversion from enumeration type error

[no-reply]

Patchew URL: https://patchew.org/QEMU/20200901153321.920490-1-laurent@vivier.eu/



Hi,

This series seems to have some coding style problems. See output below for
more information:

Type: series
Message-id: 20200901153321.920490-1-laurent@vivier.eu
Subject: [PATCH] linux-user: fix implicit conversion from enumeration type error

=== TEST SCRIPT BEGIN ===
#!/bin/bash
git rev-parse base > /dev/null || exit 0
git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram
./scripts/checkpatch.pl --mailback base..
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
Switched to a new branch 'test'
30ae5fc linux-user: fix implicit conversion from enumeration type error

=== OUTPUT BEGIN ===
ERROR: Macros with complex values should be enclosed in parenthesis
#26: FILE: include/exec/user/thunk.h:45:
+#define MK_ARRAY(type, size) TYPE_ARRAY, (int)size, type

total: 1 errors, 0 warnings, 8 lines checked

Commit 30ae5fc07c8d (linux-user: fix implicit conversion from enumeration type error) has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
=== OUTPUT END ===

Test command exited with code: 1


The full log is available at
http://patchew.org/logs/20200901153321.920490-1-laurent@vivier.eu/testing.checkpatch/?type=message.
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Please send your feedback to patchew-devel@redhat.com

Re: [PATCH] linux-user: fix implicit conversion from enumeration type error

[Philippe Mathieu-Daudé]

On 9/1/20 5:33 PM, Laurent Vivier wrote:
> MK_ARRAY(type,size) is used to fill the field_types buffer, and if the
> "size" parameter is an enum type, clang [-Werror,-Wenum-conversion] reports
> an error when it is assigned to field_types which is also an enum, argtypes.
> 
> To avoid that, convert "size" to "int" in MK_ARRAY(). "int" is the type
> used for the size evaluation in thunk_type_size().
> 
> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
> ---
>  include/exec/user/thunk.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/exec/user/thunk.h b/include/exec/user/thunk.h
> index a5bbb2c73331..b798fcb69cf4 100644
> --- a/include/exec/user/thunk.h
> +++ b/include/exec/user/thunk.h
> @@ -42,7 +42,7 @@ typedef enum argtype {
>  } argtype;
>  
>  #define MK_PTR(type) TYPE_PTR, type
> -#define MK_ARRAY(type, size) TYPE_ARRAY, size, type
> +#define MK_ARRAY(type, size) TYPE_ARRAY, (int)size, type

You need to use parenthesis:

  #define MK_ARRAY(type, size) TYPE_ARRAY, (int)(size), type

See:

  MK_ARRAY(TYPE_CHAR, USBDEVFS_MAXDRIVERNAME + 1)) /* driver */

While here I'd also add them to 'type'.

With parenthesis:
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

>  #define MK_STRUCT(id) TYPE_STRUCT, id
>  
>  #define THUNK_TARGET 0
>