* [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks
@ 2020-10-01 10:33 Dwaipayan Ray
2020-10-01 11:12 ` Lukas Bulwahn
2020-10-01 13:17 ` Joe Perches
0 siblings, 2 replies; 9+ messages in thread
From: Dwaipayan Ray @ 2020-10-01 10:33 UTC (permalink / raw)
To: joe; +Cc: dwaipayanray1, linux-kernel-mentees, linux-kernel
Checkpatch.pl doesn't have a check for excluding while (...) {...}
blocks from MULTISTATEMENT_MACRO_USE_DO_WHILE error.
For example, running checkpatch.pl on the file mm/access.c in the
kernel generates the following error:
ERROR: Macros with complex values should be enclosed in parentheses
+#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \
+ while (len >= sizeof(type)) { \
+ __get_kernel_nofault(dst, src, type, err_label); \
+ dst += sizeof(type); \
+ src += sizeof(type); \
+ len -= sizeof(type); \
+ }
The error is misleading for this case. Enclosing it in parantheses
doesn't make any sense.
Checkpatch already has an exception list for such common macro types.
Added a new exception for while (...) {...} style blocks to the same.
This effectively fixed the wrong error message.
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
---
scripts/checkpatch.pl | 1 +
1 file changed, 1 insertion(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 72c4072307ea..c2c211374662 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5342,6 +5342,7 @@ sub process {
$dstat !~ /^\.$Ident\s*=/ && # .foo =
$dstat !~ /^(?:\#\s*$Ident|\#\s*$Constant)\s*$/ && # stringification #foo
$dstat !~ /^do\s*$Constant\s*while\s*$Constant;?$/ && # do {...} while (...); // do {...} while (...)
+ $dstat !~ /^while\s*$Constant\s*$Constant\s*$/ && # while (...) {...}
$dstat !~ /^for\s*$Constant$/ && # for (...)
$dstat !~ /^for\s*$Constant\s+(?:$Ident|-?$Constant)$/ && # for (...) bar()
$dstat !~ /^do\s*{/ && # do {...
--
2.27.0
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^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks 2020-10-01 10:33 [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks Dwaipayan Ray @ 2020-10-01 11:12 ` Lukas Bulwahn 2020-10-01 13:17 ` Joe Perches 1 sibling, 0 replies; 9+ messages in thread From: Lukas Bulwahn @ 2020-10-01 11:12 UTC (permalink / raw) To: Dwaipayan Ray; +Cc: joe, linux-kernel-mentees, linux-kernel On Thu, 1 Oct 2020, Dwaipayan Ray wrote: > Checkpatch.pl doesn't have a check for excluding while (...) {...} > blocks from MULTISTATEMENT_MACRO_USE_DO_WHILE error. > > For example, running checkpatch.pl on the file mm/access.c in the > kernel generates the following error: > > ERROR: Macros with complex values should be enclosed in parentheses > +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ > + while (len >= sizeof(type)) { \ > + __get_kernel_nofault(dst, src, type, err_label); \ > + dst += sizeof(type); \ > + src += sizeof(type); \ > + len -= sizeof(type); \ > + } > > The error is misleading for this case. Enclosing it in parantheses s/parantheses/parentheses/ In my previous review, I already pointed that spelling mistake; was there a mess-up with sending out the new patch? I will start running a quick evaluation... > doesn't make any sense. > > Checkpatch already has an exception list for such common macro types. > Added a new exception for while (...) {...} style blocks to the same. > This effectively fixed the wrong error message. > > Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com> > --- > scripts/checkpatch.pl | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > index 72c4072307ea..c2c211374662 100755 > --- a/scripts/checkpatch.pl > +++ b/scripts/checkpatch.pl > @@ -5342,6 +5342,7 @@ sub process { > $dstat !~ /^\.$Ident\s*=/ && # .foo = > $dstat !~ /^(?:\#\s*$Ident|\#\s*$Constant)\s*$/ && # stringification #foo > $dstat !~ /^do\s*$Constant\s*while\s*$Constant;?$/ && # do {...} while (...); // do {...} while (...) > + $dstat !~ /^while\s*$Constant\s*$Constant\s*$/ && # while (...) {...} > $dstat !~ /^for\s*$Constant$/ && # for (...) > $dstat !~ /^for\s*$Constant\s+(?:$Ident|-?$Constant)$/ && # for (...) bar() > $dstat !~ /^do\s*{/ && # do {... > -- > 2.27.0 > > _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks 2020-10-01 10:33 [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks Dwaipayan Ray 2020-10-01 11:12 ` Lukas Bulwahn @ 2020-10-01 13:17 ` Joe Perches 2020-10-01 13:27 ` Dwaipayan Ray 1 sibling, 1 reply; 9+ messages in thread From: Joe Perches @ 2020-10-01 13:17 UTC (permalink / raw) To: Dwaipayan Ray; +Cc: linux-kernel-mentees, linux-kernel On Thu, 2020-10-01 at 16:03 +0530, Dwaipayan Ray wrote: > Checkpatch.pl doesn't have a check for excluding while (...) {...} > blocks from MULTISTATEMENT_MACRO_USE_DO_WHILE error. > > For example, running checkpatch.pl on the file mm/access.c in the > kernel generates the following error: > > ERROR: Macros with complex values should be enclosed in parentheses > +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ > + while (len >= sizeof(type)) { \ > + __get_kernel_nofault(dst, src, type, err_label); \ > + dst += sizeof(type); \ > + src += sizeof(type); \ > + len -= sizeof(type); \ > + } > > The error is misleading for this case. Enclosing it in parantheses > doesn't make any sense. OK > Checkpatch already has an exception list for such common macro types. > Added a new exception for while (...) {...} style blocks to the same. > This effectively fixed the wrong error message. [] > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl [] > @@ -5342,6 +5342,7 @@ sub process { > $dstat !~ /^\.$Ident\s*=/ && # .foo = > $dstat !~ /^(?:\#\s*$Ident|\#\s*$Constant)\s*$/ && # stringification #foo > $dstat !~ /^do\s*$Constant\s*while\s*$Constant;?$/ && # do {...} while (...); // do {...} while (...) > + $dstat !~ /^while\s*$Constant\s*$Constant\s*$/ && # while (...) {...} Did you try to output $dstat for some matching cases? What was the $dstat value for the cases you tried? _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks 2020-10-01 13:17 ` Joe Perches @ 2020-10-01 13:27 ` Dwaipayan Ray 2020-10-01 13:42 ` Joe Perches 0 siblings, 1 reply; 9+ messages in thread From: Dwaipayan Ray @ 2020-10-01 13:27 UTC (permalink / raw) To: Joe Perches; +Cc: linux-kernel-mentees, linux-kernel On Thu, Oct 1, 2020 at 6:47 PM Joe Perches <joe@perches.com> wrote: > > On Thu, 2020-10-01 at 16:03 +0530, Dwaipayan Ray wrote: > > Checkpatch.pl doesn't have a check for excluding while (...) {...} > > blocks from MULTISTATEMENT_MACRO_USE_DO_WHILE error. > > > > For example, running checkpatch.pl on the file mm/access.c in the > > kernel generates the following error: > > > > ERROR: Macros with complex values should be enclosed in parentheses > > +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ > > + while (len >= sizeof(type)) { \ > > + __get_kernel_nofault(dst, src, type, err_label); \ > > + dst += sizeof(type); \ > > + src += sizeof(type); \ > > + len -= sizeof(type); \ > > + } > > > > The error is misleading for this case. Enclosing it in parantheses > > doesn't make any sense. > > OK > > > Checkpatch already has an exception list for such common macro types. > > Added a new exception for while (...) {...} style blocks to the same. > > This effectively fixed the wrong error message. > [] > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > [] > > @@ -5342,6 +5342,7 @@ sub process { > > $dstat !~ /^\.$Ident\s*=/ && # .foo = > > $dstat !~ /^(?:\#\s*$Ident|\#\s*$Constant)\s*$/ && # stringification #foo > > $dstat !~ /^do\s*$Constant\s*while\s*$Constant;?$/ && # do {...} while (...); // do {...} while (...) > > + $dstat !~ /^while\s*$Constant\s*$Constant\s*$/ && # while (...) {...} > > Did you try to output $dstat for some matching cases? > What was the $dstat value for the cases you tried? > > Hi, I did check $dstat values. For example on file mm/maccess.c, there were two such macros: Case 1: $ctx: +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ + while (len >= sizeof(type)) { \ + __get_kernel_nofault(dst, src, type, err_label); \ + dst += sizeof(type); \ + src += sizeof(type); \ + len -= sizeof(type); \ + } $dstat: while 1 1 Case 2: $ctx: +#define copy_to_kernel_nofault_loop(dst, src, len, type, err_label) \ + while (len >= sizeof(type)) { \ + __put_kernel_nofault(dst, src, type, err_label); \ + dst += sizeof(type); \ + src += sizeof(type); \ + len -= sizeof(type); \ + } $dstat: while 1 1 Thanks, Dwaipayan. _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks 2020-10-01 13:27 ` Dwaipayan Ray @ 2020-10-01 13:42 ` Joe Perches 2020-10-01 14:14 ` Dwaipayan Ray 0 siblings, 1 reply; 9+ messages in thread From: Joe Perches @ 2020-10-01 13:42 UTC (permalink / raw) To: Dwaipayan Ray; +Cc: linux-kernel-mentees, linux-kernel On Thu, 2020-10-01 at 18:57 +0530, Dwaipayan Ray wrote: > On Thu, Oct 1, 2020 at 6:47 PM Joe Perches <joe@perches.com> wrote: > > On Thu, 2020-10-01 at 16:03 +0530, Dwaipayan Ray wrote: > > > Checkpatch.pl doesn't have a check for excluding while (...) {...} > > > blocks from MULTISTATEMENT_MACRO_USE_DO_WHILE error. > > > > > > For example, running checkpatch.pl on the file mm/access.c in the > > > kernel generates the following error: > > > > > > ERROR: Macros with complex values should be enclosed in parentheses > > > +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ > > > + while (len >= sizeof(type)) { \ > > > + __get_kernel_nofault(dst, src, type, err_label); \ > > > + dst += sizeof(type); \ > > > + src += sizeof(type); \ > > > + len -= sizeof(type); \ > > > + } > > > > > > The error is misleading for this case. Enclosing it in parantheses > > > doesn't make any sense. > > > > OK > > > > > Checkpatch already has an exception list for such common macro types. > > > Added a new exception for while (...) {...} style blocks to the same. > > > This effectively fixed the wrong error message. > > [] > > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > > [] > > > @@ -5342,6 +5342,7 @@ sub process { > > > $dstat !~ /^\.$Ident\s*=/ && # .foo = > > > $dstat !~ /^(?:\#\s*$Ident|\#\s*$Constant)\s*$/ && # stringification #foo > > > $dstat !~ /^do\s*$Constant\s*while\s*$Constant;?$/ && # do {...} while (...); // do {...} while (...) > > > + $dstat !~ /^while\s*$Constant\s*$Constant\s*$/ && # while (...) {...} Note the \s* ^ > > Did you try to output $dstat for some matching cases? > > What was the $dstat value for the cases you tried? > > > > > Hi, > I did check $dstat values. > > For example on file mm/maccess.c, there were two such macros: > > Case 1: > > $ctx: > +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ > + while (len >= sizeof(type)) { \ > + __get_kernel_nofault(dst, src, type, err_label); \ > + dst += sizeof(type); \ > + src += sizeof(type); \ > + len -= sizeof(type); \ > + } > > $dstat: > while 1 1 And perhaps this test should use \s+ instead. What is $dstat with a #define like: #define foo(bar,baz)while(bar){bar--;baz++;} (no spaces anywhere bot the required one after define > Case 2: > > $ctx: > +#define copy_to_kernel_nofault_loop(dst, src, len, type, err_label) \ > + while (len >= sizeof(type)) { \ > + __put_kernel_nofault(dst, src, type, err_label); \ > + dst += sizeof(type); \ > + src += sizeof(type); \ > + len -= sizeof(type); \ > + } > > $dstat: > while 1 1 > > > Thanks, > Dwaipayan. _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks 2020-10-01 13:42 ` Joe Perches @ 2020-10-01 14:14 ` Dwaipayan Ray 2020-10-01 14:38 ` Joe Perches 0 siblings, 1 reply; 9+ messages in thread From: Dwaipayan Ray @ 2020-10-01 14:14 UTC (permalink / raw) To: Joe Perches; +Cc: linux-kernel-mentees, linux-kernel On Thu, Oct 1, 2020 at 7:12 PM Joe Perches <joe@perches.com> wrote: > > On Thu, 2020-10-01 at 18:57 +0530, Dwaipayan Ray wrote: > > On Thu, Oct 1, 2020 at 6:47 PM Joe Perches <joe@perches.com> wrote: > > > On Thu, 2020-10-01 at 16:03 +0530, Dwaipayan Ray wrote: > > > > Checkpatch.pl doesn't have a check for excluding while (...) {...} > > > > blocks from MULTISTATEMENT_MACRO_USE_DO_WHILE error. > > > > > > > > For example, running checkpatch.pl on the file mm/access.c in the > > > > kernel generates the following error: > > > > > > > > ERROR: Macros with complex values should be enclosed in parentheses > > > > +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ > > > > + while (len >= sizeof(type)) { \ > > > > + __get_kernel_nofault(dst, src, type, err_label); \ > > > > + dst += sizeof(type); \ > > > > + src += sizeof(type); \ > > > > + len -= sizeof(type); \ > > > > + } > > > > > > > > The error is misleading for this case. Enclosing it in parantheses > > > > doesn't make any sense. > > > > > > OK > > > > > > > Checkpatch already has an exception list for such common macro types. > > > > Added a new exception for while (...) {...} style blocks to the same. > > > > This effectively fixed the wrong error message. > > > [] > > > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > > > [] > > > > @@ -5342,6 +5342,7 @@ sub process { > > > > $dstat !~ /^\.$Ident\s*=/ && # .foo = > > > > $dstat !~ /^(?:\#\s*$Ident|\#\s*$Constant)\s*$/ && # stringification #foo > > > > $dstat !~ /^do\s*$Constant\s*while\s*$Constant;?$/ && # do {...} while (...); // do {...} while (...) > > > > + $dstat !~ /^while\s*$Constant\s*$Constant\s*$/ && # while (...) {...} > > Note the \s* > ^ > > > > Did you try to output $dstat for some matching cases? > > > What was the $dstat value for the cases you tried? > > > > > > > > Hi, > > I did check $dstat values. > > > > For example on file mm/maccess.c, there were two such macros: > > > > Case 1: > > > > $ctx: > > +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ > > + while (len >= sizeof(type)) { \ > > + __get_kernel_nofault(dst, src, type, err_label); \ > > + dst += sizeof(type); \ > > + src += sizeof(type); \ > > + len -= sizeof(type); \ > > + } > > > > $dstat: > > while 1 1 > > And perhaps this test should use \s+ instead. > What is $dstat with a #define like: > > #define foo(bar,baz)while(bar){bar--;baz++;} > > (no spaces anywhere bot the required one after define > In this case, $dstat is: while11 So, if \s+ is used, it won't match with this. I ran checkpatch on it and some other condition seems to match, so it is excluded from the error. However, if the macro is like: #define foo(bar,baz)while(bar) {bar--;baz++;} (one space after condition) $dstat is: while1 1 (space after first 1) and the same error is again emitted. So I think \s* works better since there can be 0 or more whitespaces between them. Thanks, Dwaipayan. _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks 2020-10-01 14:14 ` Dwaipayan Ray @ 2020-10-01 14:38 ` Joe Perches 2020-10-01 15:26 ` Joe Perches 0 siblings, 1 reply; 9+ messages in thread From: Joe Perches @ 2020-10-01 14:38 UTC (permalink / raw) To: Dwaipayan Ray; +Cc: linux-kernel-mentees, linux-kernel On Thu, 2020-10-01 at 19:44 +0530, Dwaipayan Ray wrote: > On Thu, Oct 1, 2020 at 7:12 PM Joe Perches <joe@perches.com> wrote: > > On Thu, 2020-10-01 at 18:57 +0530, Dwaipayan Ray wrote: > > > On Thu, Oct 1, 2020 at 6:47 PM Joe Perches <joe@perches.com> wrote: > > > > On Thu, 2020-10-01 at 16:03 +0530, Dwaipayan Ray wrote: > > > > > Checkpatch.pl doesn't have a check for excluding while (...) {...} > > > > > blocks from MULTISTATEMENT_MACRO_USE_DO_WHILE error. > > > > > > > > > > For example, running checkpatch.pl on the file mm/access.c in the > > > > > kernel generates the following error: > > > > > > > > > > ERROR: Macros with complex values should be enclosed in parentheses > > > > > +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ > > > > > + while (len >= sizeof(type)) { \ > > > > > + __get_kernel_nofault(dst, src, type, err_label); \ > > > > > + dst += sizeof(type); \ > > > > > + src += sizeof(type); \ > > > > > + len -= sizeof(type); \ > > > > > + } > > > > > > > > > > The error is misleading for this case. Enclosing it in parantheses > > > > > doesn't make any sense. > > > > > > > > OK > > > > > > > > > Checkpatch already has an exception list for such common macro types. > > > > > Added a new exception for while (...) {...} style blocks to the same. > > > > > This effectively fixed the wrong error message. > > > > [] > > > > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > > > > [] > > > > > @@ -5342,6 +5342,7 @@ sub process { > > > > > $dstat !~ /^\.$Ident\s*=/ && # .foo = > > > > > $dstat !~ /^(?:\#\s*$Ident|\#\s*$Constant)\s*$/ && # stringification #foo > > > > > $dstat !~ /^do\s*$Constant\s*while\s*$Constant;?$/ && # do {...} while (...); // do {...} while (...) > > > > > + $dstat !~ /^while\s*$Constant\s*$Constant\s*$/ && # while (...) {...} > > > > Note the \s* > > ^ > > > > > > Did you try to output $dstat for some matching cases? > > > > What was the $dstat value for the cases you tried? > > > > > > > > > > > Hi, > > > I did check $dstat values. > > > > > > For example on file mm/maccess.c, there were two such macros: > > > > > > Case 1: > > > > > > $ctx: > > > +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ > > > + while (len >= sizeof(type)) { \ > > > + __get_kernel_nofault(dst, src, type, err_label); \ > > > + dst += sizeof(type); \ > > > + src += sizeof(type); \ > > > + len -= sizeof(type); \ > > > + } > > > > > > $dstat: > > > while 1 1 > > > > And perhaps this test should use \s+ instead. > > What is $dstat with a #define like: > > > > #define foo(bar,baz)while(bar){bar--;baz++;} > > > > (no spaces anywhere bot the required one after define > > > > In this case, $dstat is: while11 > > So, if \s+ is used, it won't match with this. I ran checkpatch > on it and some other condition seems to match, so it is > excluded from the error. > > However, if the macro is like: > > #define foo(bar,baz)while(bar) {bar--;baz++;} > (one space after condition) > > $dstat is: while1 1 > (space after first 1) > and the same error is again emitted. > > So I think \s* works better since there can be > 0 or more whitespaces between them. All I'm trying to point out to you is that $Constant\s*$Constant isn't a proper test as the first $Constant will pull the test entire sequence of digits and the second $Constant will not be met. It may take some conversion of the collapsing of the dstat block to work appropriately # Flatten any parentheses and braces while ($dstat =~ s/\([^\(\)]*\)/1/ || $dstat =~ s/\{[^\{\}]*\}/1/ || $dstat =~ s/.\[[^\[\]]*\]/1/) { } Maybe the /1/ should be / 1 / but I didn't look to see what happens to the exclusion tests below that. _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks 2020-10-01 14:38 ` Joe Perches @ 2020-10-01 15:26 ` Joe Perches 2020-10-01 15:36 ` Dwaipayan Ray 0 siblings, 1 reply; 9+ messages in thread From: Joe Perches @ 2020-10-01 15:26 UTC (permalink / raw) To: Dwaipayan Ray; +Cc: linux-kernel-mentees, linux-kernel On Thu, 2020-10-01 at 07:38 -0700, Joe Perches wrote: > On Thu, 2020-10-01 at 19:44 +0530, Dwaipayan Ray wrote: > > On Thu, Oct 1, 2020 at 7:12 PM Joe Perches <joe@perches.com> wrote: > > > On Thu, 2020-10-01 at 18:57 +0530, Dwaipayan Ray wrote: > > > > On Thu, Oct 1, 2020 at 6:47 PM Joe Perches <joe@perches.com> wrote: > > > > > On Thu, 2020-10-01 at 16:03 +0530, Dwaipayan Ray wrote: > > > > > > Checkpatch.pl doesn't have a check for excluding while (...) {...} > > > > > > blocks from MULTISTATEMENT_MACRO_USE_DO_WHILE error. > > > > > > > > > > > > For example, running checkpatch.pl on the file mm/access.c in the > > > > > > kernel generates the following error: > > > > > > > > > > > > ERROR: Macros with complex values should be enclosed in parentheses > > > > > > +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ > > > > > > + while (len >= sizeof(type)) { \ > > > > > > + __get_kernel_nofault(dst, src, type, err_label); \ > > > > > > + dst += sizeof(type); \ > > > > > > + src += sizeof(type); \ > > > > > > + len -= sizeof(type); \ > > > > > > + } > > > > > > > > > > > > The error is misleading for this case. Enclosing it in parantheses > > > > > > doesn't make any sense. > > > > > > > > > > OK > > > > > > > > > > > Checkpatch already has an exception list for such common macro types. > > > > > > Added a new exception for while (...) {...} style blocks to the same. > > > > > > This effectively fixed the wrong error message. > > > > > [] > > > > > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > > > > > [] > > > > > > @@ -5342,6 +5342,7 @@ sub process { > > > > > > $dstat !~ /^\.$Ident\s*=/ && # .foo = > > > > > > $dstat !~ /^(?:\#\s*$Ident|\#\s*$Constant)\s*$/ && # stringification #foo > > > > > > $dstat !~ /^do\s*$Constant\s*while\s*$Constant;?$/ && # do {...} while (...); // do {...} while (...) > > > > > > + $dstat !~ /^while\s*$Constant\s*$Constant\s*$/ && # while (...) {...} > > > > > > Note the \s* > > > ^ > > > > > > > > Did you try to output $dstat for some matching cases? > > > > > What was the $dstat value for the cases you tried? > > > > > > > > > > > > > > Hi, > > > > I did check $dstat values. > > > > > > > > For example on file mm/maccess.c, there were two such macros: > > > > > > > > Case 1: > > > > > > > > $ctx: > > > > +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ > > > > + while (len >= sizeof(type)) { \ > > > > + __get_kernel_nofault(dst, src, type, err_label); \ > > > > + dst += sizeof(type); \ > > > > + src += sizeof(type); \ > > > > + len -= sizeof(type); \ > > > > + } > > > > > > > > $dstat: > > > > while 1 1 > > > > > > And perhaps this test should use \s+ instead. > > > What is $dstat with a #define like: > > > > > > #define foo(bar,baz)while(bar){bar--;baz++;} > > > > > > (no spaces anywhere bot the required one after define > > > > > > > In this case, $dstat is: while11 > > > > So, if \s+ is used, it won't match with this. I ran checkpatch > > on it and some other condition seems to match, so it is > > excluded from the error. > > > > However, if the macro is like: > > > > #define foo(bar,baz)while(bar) {bar--;baz++;} > > (one space after condition) > > > > $dstat is: while1 1 > > (space after first 1) > > and the same error is again emitted. > > > > So I think \s* works better since there can be > > 0 or more whitespaces between them. > > All I'm trying to point out to you is that $Constant\s*$Constant > isn't a proper test as the first $Constant will pull the test > entire sequence of digits and the second $Constant will not be > met. > > It may take some conversion of the collapsing of the dstat > block to work appropriately > > > # Flatten any parentheses and braces > while ($dstat =~ s/\([^\(\)]*\)/1/ || > $dstat =~ s/\{[^\{\}]*\}/1/ || > $dstat =~ s/.\[[^\[\]]*\]/1/) > { > } > > Maybe the /1/ should be / 1 / but I didn't look to see what > happens to the exclusion tests below that. I think your patch would work well enough if the /1/ bits here were simply changed to /1u/. 1 is a $Constant as it's just a number. 11 though is also a $Constant. 1u is also a $Constant but it stops the acquisition of digits that 11 would not and the sequence of "while1u1u" should match your newly introduced test of $Constant\s*$Constant as "while11" would not match. > _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks 2020-10-01 15:26 ` Joe Perches @ 2020-10-01 15:36 ` Dwaipayan Ray 0 siblings, 0 replies; 9+ messages in thread From: Dwaipayan Ray @ 2020-10-01 15:36 UTC (permalink / raw) To: Joe Perches; +Cc: linux-kernel-mentees, linux-kernel > > All I'm trying to point out to you is that $Constant\s*$Constant > > isn't a proper test as the first $Constant will pull the test > > entire sequence of digits and the second $Constant will not be > > met. > > > > It may take some conversion of the collapsing of the dstat > > block to work appropriately > > > > > > # Flatten any parentheses and braces > > while ($dstat =~ s/\([^\(\)]*\)/1/ || > > $dstat =~ s/\{[^\{\}]*\}/1/ || > > $dstat =~ s/.\[[^\[\]]*\]/1/) > > { > > } > > > > Maybe the /1/ should be / 1 / but I didn't look to see what > > happens to the exclusion tests below that. > > I think your patch would work well enough if the /1/ bits > here were simply changed to /1u/. > > 1 is a $Constant as it's just a number. > 11 though is also a $Constant. > 1u is also a $Constant but it stops the acquisition of > digits that 11 would not and the sequence of > "while1u1u" should match your newly introduced test > of $Constant\s*$Constant as "while11" would not match. > > Hi, That's an amazing idea! I tried it and this time it seems to detect it properly. Also this fixes the similar case in for(...) {...}. It should not have any side effects also for other checks. Pretty amazing. I will rewrite the patch with your suggestion and send it back. Thanks, Dwaipayan. _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2020-10-01 16:53 UTC | newest] Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-10-01 10:33 [Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks Dwaipayan Ray 2020-10-01 11:12 ` Lukas Bulwahn 2020-10-01 13:17 ` Joe Perches 2020-10-01 13:27 ` Dwaipayan Ray 2020-10-01 13:42 ` Joe Perches 2020-10-01 14:14 ` Dwaipayan Ray 2020-10-01 14:38 ` Joe Perches 2020-10-01 15:26 ` Joe Perches 2020-10-01 15:36 ` Dwaipayan Ray
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