On 02/07/2024 11:00, lijiang wrote: > On Thu, Jun 27, 2024 at 4:31 PM <devel-request@xxxxxxxxxxxxxxxxxxxxxxxxxxx <mailto:devel-request@xxxxxxxxxxxxxxxxxxxxxxxxxxx>> wrote: > > Date: Thu, 27 Jun 2024 11:18:29 +0800 > From: Li Zhijian <lizhijian@xxxxxxxxxxx <mailto:lizhijian@xxxxxxxxxxx>> > Subject: [PATCH] list: fatal if -r isn't used in > conjunction with -H or -h > To: devel@xxxxxxxxxxxxxxxxxxxxxxxxxxx <mailto:devel@xxxxxxxxxxxxxxxxxxxxxxxxxxx> > Cc: Li Zhijian <lizhijian@xxxxxxxxxxx <mailto:lizhijian@xxxxxxxxxxx>> > Message-ID: <20240627031829.235256-1-lizhijian@xxxxxxxxxxx <mailto:20240627031829.235256-1-lizhijian@xxxxxxxxxxx>> > > Per the code, -r(LIST_HEAD_REVERSE) only work with LIST_HEAD_FORMAT > which is set by -H or -h. > > Previously, if LIST_HEAD_FORMAT was not set, `list -r` will traverse the > list in order, that doesn't obey the -r(reverse) semantics. > > According to the above descriptions, I guess that it should be: > > diff --git a/tools.c b/tools.c > index 0f2db108838a..1022d579071a 100644 > --- a/tools.c > +++ b/tools.c > @@ -3370,6 +3370,7 @@ cmd_list(void) > break; > > case 'r': > + ld->flags |= LIST_HEAD_FORMAT; Cool, It sounds more better/accurate. " -r For a list linked with list_head structures, traverse the list", " in the reverse order by using the \"prev\" pointer instead", " of \"next\".", -r usage also says it's used for list_head structure. So implicitly enable LIST_HEAD_REVERSE is reasonable. Thanks Zhijian > ld->flags |= LIST_HEAD_REVERSE; > break; > > Also let's see the following code: > > if (ld->flags & LIST_HEAD_FORMAT) { > ld->list_head_offset = ld->member_offset; > if (ld->flags & LIST_HEAD_REVERSE) > ld->member_offset = sizeof(void *); > else > ld->member_offset = 0; > > Furthermore, the help page is: > SYNOPSIS > list [[-o] offset][-e end][-[s|S] struct[.member[,member] [-l offset]] -[x|d]] > [-r|-B] [-h [-O head_offset]|-H] start > > The '-r' looks like an optional option, just like '-h' and '-H'. > > Can you help double check? > > Thanks > Lianbo > > Add a further check to ensure -r is used in conjunction with -H or -h. > > Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx <mailto:lizhijian@xxxxxxxxxxx>> > --- > help.c | 3 ++- > tools.c | 3 +++ > 2 files changed, 5 insertions(+), 1 deletion(-) > > diff --git a/help.c b/help.c > index d80e843703c1..6f7e093cbef1 100644 > --- a/help.c > +++ b/help.c > @@ -5977,7 +5977,8 @@ char *help__list[] = { > " ", > " -x Override the default output format with hexadecimal format.", > " -d Override the default output format with decimal format.", > -" -r For a list linked with list_head structures, traverse the list", > +" -r Must be used in conjunction with either -H or -h.", > +" For a list linked with list_head structures, traverse the list", > " in the reverse order by using the \"prev\" pointer instead", > " of \"next\".", > " -B Use the algorithm from R. P. Brent to detect loops instead of", > diff --git a/tools.c b/tools.c > index 0f2db108838a..67977605c276 100644 > --- a/tools.c > +++ b/tools.c > @@ -3451,6 +3451,9 @@ cmd_list(void) > } > } > > + if (ld->flags & LIST_HEAD_REVERSE && !(ld->flags & LIST_HEAD_FORMAT)) > + error(FATAL, "-r must be used in conjunction with -H or -h\n"); > + > if (argerrs) > cmd_usage(pc->curcmd, SYNOPSIS); > > -- > 2.29.2 > -- Crash-utility mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxxxxxx https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ Contribution Guidelines: https://github.com/crash-utility/crash/wiki
