From: Kaixu Xia <[email protected]>
Fix following warning from coccinelle:
./tools/lib/bpf/libbpf.c:1478:43-48: WARNING: conversion to bool not needed here
Signed-off-by: Kaixu Xia <[email protected]>
---
tools/lib/bpf/libbpf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 313034117070..fb9625077983 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1475,7 +1475,7 @@ static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val,
ext->name, value);
return -EINVAL;
}
- *(bool *)ext_val = value == 'y' ? true : false;
+ *(bool *)ext_val = value == 'y';
break;
case KCFG_TRISTATE:
if (value == 'y')
--
2.20.0
On Thu, Nov 5, 2020 at 11:12 PM <[email protected]> wrote:
>
> From: Kaixu Xia <[email protected]>
>
> Fix following warning from coccinelle:
>
> ./tools/lib/bpf/libbpf.c:1478:43-48: WARNING: conversion to bool not needed here
>
> Signed-off-by: Kaixu Xia <[email protected]>
> ---
> tools/lib/bpf/libbpf.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 313034117070..fb9625077983 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -1475,7 +1475,7 @@ static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val,
> ext->name, value);
> return -EINVAL;
> }
> - *(bool *)ext_val = value == 'y' ? true : false;
> + *(bool *)ext_val = value == 'y';
I actually did this intentionally. x = y == z; pattern looked too
obscure to my taste, tbh.
> break;
> case KCFG_TRISTATE:
> if (value == 'y')
> --
> 2.20.0
>
On Fri, 2020-11-06 at 13:32 -0800, Andrii Nakryiko wrote:
> On Thu, Nov 5, 2020 at 11:12 PM <[email protected]> wrote:
> > Fix following warning from coccinelle:
> > ./tools/lib/bpf/libbpf.c:1478:43-48: WARNING: conversion to bool not needed here
[]
> > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
[]
> > @@ -1475,7 +1475,7 @@ static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val,
> > ????????????????????????????????ext->name, value);
> > ????????????????????????return -EINVAL;
> > ????????????????}
> > - *(bool *)ext_val = value == 'y' ? true : false;
> > + *(bool *)ext_val = value == 'y';
>
> I actually did this intentionally. x = y == z; pattern looked too
> obscure to my taste, tbh.
It's certainly a question of taste and obviously there is nothing
wrong with yours.
Maybe adding parentheses makes the below look less obscure to you?
x = (y == z);
My taste would run to something like:
---
tools/lib/bpf/libbpf.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 313034117070..5d9c9c8d50c9 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1469,25 +1469,34 @@ static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val,
char value)
{
switch (ext->kcfg.type) {
- case KCFG_BOOL:
+ case KCFG_BOOL: {
+ bool *p = ext_val;
+
if (value == 'm') {
pr_warn("extern (kcfg) %s=%c should be tristate or char\n",
ext->name, value);
return -EINVAL;
}
- *(bool *)ext_val = value == 'y' ? true : false;
+ *p = (value == 'y');
break;
- case KCFG_TRISTATE:
+ }
+ case KCFG_TRISTATE: {
+ enum libbpf_tristate *p = ext_val;
+
if (value == 'y')
- *(enum libbpf_tristate *)ext_val = TRI_YES;
+ *p = TRI_YES;
else if (value == 'm')
- *(enum libbpf_tristate *)ext_val = TRI_MODULE;
+ *p = TRI_MODULE;
else /* value == 'n' */
- *(enum libbpf_tristate *)ext_val = TRI_NO;
+ *p = TRI_NO;
break;
- case KCFG_CHAR:
- *(char *)ext_val = value;
+ }
+ case KCFG_CHAR: {
+ char *p = ext_val;
+
+ *p = value;
break;
+ }
case KCFG_UNKNOWN:
case KCFG_INT:
case KCFG_CHAR_ARR:
On Fri, Nov 6, 2020 at 1:50 PM Joe Perches <[email protected]> wrote:
>
> On Fri, 2020-11-06 at 13:32 -0800, Andrii Nakryiko wrote:
> > On Thu, Nov 5, 2020 at 11:12 PM <[email protected]> wrote:
> > > Fix following warning from coccinelle:
> > > ./tools/lib/bpf/libbpf.c:1478:43-48: WARNING: conversion to bool not needed here
> []
> > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> []
> > > @@ -1475,7 +1475,7 @@ static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val,
> > > ext->name, value);
> > > return -EINVAL;
> > > }
> > > - *(bool *)ext_val = value == 'y' ? true : false;
> > > + *(bool *)ext_val = value == 'y';
> >
> > I actually did this intentionally. x = y == z; pattern looked too
> > obscure to my taste, tbh.
>
> It's certainly a question of taste and obviously there is nothing
> wrong with yours.
>
> Maybe adding parentheses makes the below look less obscure to you?
>
> x = (y == z);
Yeah, I think this would be explicit enough. But let's keep the *(bool
*) cast and keep switch code shorter and without extra {} block.
>
> My taste would run to something like:
> ---
> tools/lib/bpf/libbpf.c | 25 +++++++++++++++++--------
> 1 file changed, 17 insertions(+), 8 deletions(-)
>
[...]
From: Joe Perches
> Sent: 06 November 2020 21:50
>
> On Fri, 2020-11-06 at 13:32 -0800, Andrii Nakryiko wrote:
> > On Thu, Nov 5, 2020 at 11:12 PM <[email protected]> wrote:
> > > Fix following warning from coccinelle:
> > > ./tools/lib/bpf/libbpf.c:1478:43-48: WARNING: conversion to bool not needed here
> []
> > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> []
> > > @@ -1475,7 +1475,7 @@ static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val,
> > > ext->name, value);
> > > return -EINVAL;
> > > }
> > > - *(bool *)ext_val = value == 'y' ? true : false;
> > > + *(bool *)ext_val = value == 'y';
> >
> > I actually did this intentionally. x = y == z; pattern looked too
> > obscure to my taste, tbh.
>
> It's certainly a question of taste and obviously there is nothing
> wrong with yours.
>
> Maybe adding parentheses makes the below look less obscure to you?
>
> x = (y == z);
That just leads to people thinking conditionals need to be in parentheses
and then getting the priorities for ?: all wrong as in:
x = a + (b == c) ? d : e;
It would (probably) be better to make 'ext_val' be a union type
(probably a 'pointer to a union' rather than a union of pointers)
so that all the casts go away.
David
-
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