[libvirt] [PATCH 0/2] vsh: Print help for the aliased cmd rather than the alias itself
The alias doesn't have any definition rather than a reference for the aliased command. Therefore when printing help, we have to print help for the aliased command, otherwise our faith is going to be met with SIGSEGV. Erik Skultety (2): vsh: Drop redundant definition searches from vshCmd{def,Grp}Help vsh: Cmd aliases lookups should return results for the aliased command tools/vsh.c | 45 +++++++++++++++++---------------------------- tools/vsh.h | 4 ++-- 2 files changed, 19 insertions(+), 30 deletions(-) -- 2.13.6
These helpers are called from a single place only - cmdHelp wrapper and just before the wrapper invokes the helpers, it performs the search, either for command group or for the command itself, except the result is discarded and the helper therefore needs to do it again. Drop this inefficient handling and pass the @def structure rather than a name, thus preventing the helper from needing to perform the search again. Signed-off-by: Erik Skultety <eskultet@redhat.com> --- tools/vsh.c | 43 +++++++++++++++---------------------------- tools/vsh.h | 4 ++-- 2 files changed, 17 insertions(+), 30 deletions(-) diff --git a/tools/vsh.c b/tools/vsh.c index 058df7ef6..761d2ec3a 100644 --- a/tools/vsh.c +++ b/tools/vsh.c @@ -629,44 +629,32 @@ vshCmdGrpSearch(const char *grpname) } bool -vshCmdGrpHelp(vshControl *ctl, const char *grpname) +vshCmdGrpHelp(vshControl *ctl, const vshCmdGrp *grp) { - const vshCmdGrp *grp = vshCmdGrpSearch(grpname); const vshCmdDef *cmd = NULL; - if (!grp) { - vshError(ctl, _("command group '%s' doesn't exist"), grpname); - return false; - } else { - vshPrint(ctl, _(" %s (help keyword '%s'):\n"), grp->name, - grp->keyword); + vshPrint(ctl, _(" %s (help keyword '%s'):\n"), grp->name, + grp->keyword); - for (cmd = grp->commands; cmd->name; cmd++) { - if (cmd->flags & VSH_CMD_FLAG_ALIAS) - continue; - vshPrint(ctl, " %-30s %s\n", cmd->name, - _(vshCmddefGetInfo(cmd, "help"))); - } + for (cmd = grp->commands; cmd->name; cmd++) { + if (cmd->flags & VSH_CMD_FLAG_ALIAS) + continue; + vshPrint(ctl, " %-30s %s\n", cmd->name, + _(vshCmddefGetInfo(cmd, "help"))); } return true; } bool -vshCmddefHelp(vshControl *ctl, const char *cmdname) +vshCmddefHelp(vshControl *ctl, const vshCmdDef *def) { - const vshCmdDef *def = vshCmddefSearch(cmdname); const char *desc = NULL; char buf[256]; uint64_t opts_need_arg; uint64_t opts_required; bool shortopt = false; /* true if 'arg' works instead of '--opt arg' */ - if (!def) { - vshError(ctl, _("command '%s' doesn't exist"), cmdname); - return false; - } - if (vshCmddefOptParse(def, &opts_need_arg, &opts_required)) { vshError(ctl, _("internal error: bad options in command: '%s'"), def->name); @@ -3181,12 +3169,11 @@ const vshCmdInfo info_help[] = { bool cmdHelp(vshControl *ctl, const vshCmd *cmd) { + const vshCmdDef *def = NULL; + const vshCmdGrp *grp = NULL; const char *name = NULL; if (vshCommandOptStringQuiet(ctl, cmd, "command", &name) <= 0) { - const vshCmdGrp *grp; - const vshCmdDef *def; - vshPrint(ctl, "%s", _("Grouped commands:\n\n")); for (grp = cmdGroups; grp->name; grp++) { @@ -3206,10 +3193,10 @@ cmdHelp(vshControl *ctl, const vshCmd *cmd) return true; } - if (vshCmddefSearch(name)) { - return vshCmddefHelp(ctl, name); - } else if (vshCmdGrpSearch(name)) { - return vshCmdGrpHelp(ctl, name); + if ((def = vshCmddefSearch(name))) { + return vshCmddefHelp(ctl, def); + } else if ((grp = vshCmdGrpSearch(name))) { + return vshCmdGrpHelp(ctl, grp); } else { vshError(ctl, _("command or command group '%s' doesn't exist"), name); return false; diff --git a/tools/vsh.h b/tools/vsh.h index 6894700d9..694476471 100644 --- a/tools/vsh.h +++ b/tools/vsh.h @@ -257,9 +257,9 @@ void vshCloseLogFile(vshControl *ctl); const char *vshCmddefGetInfo(const vshCmdDef *cmd, const char *info); const vshCmdDef *vshCmddefSearch(const char *cmdname); -bool vshCmddefHelp(vshControl *ctl, const char *name); +bool vshCmddefHelp(vshControl *ctl, const vshCmdDef *def); const vshCmdGrp *vshCmdGrpSearch(const char *grpname); -bool vshCmdGrpHelp(vshControl *ctl, const char *name); +bool vshCmdGrpHelp(vshControl *ctl, const vshCmdGrp *grp); int vshCommandOptInt(vshControl *ctl, const vshCmd *cmd, const char *name, int *value) -- 2.13.6
Unfortunately, we have a number of aliases in virsh and even though these are not visible any more, we have to support them. The problem is that when trying to print help for the alias, we get SIGSEGV because there isn't any @def structure anymore and we need to query the command being aliased instead. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1538570 Signed-off-by: Erik Skultety <eskultet@redhat.com> --- tools/vsh.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/vsh.c b/tools/vsh.c index 761d2ec3a..37c292a03 100644 --- a/tools/vsh.c +++ b/tools/vsh.c @@ -3194,6 +3194,8 @@ cmdHelp(vshControl *ctl, const vshCmd *cmd) } if ((def = vshCmddefSearch(name))) { + if (def->flags & VSH_CMD_FLAG_ALIAS) + def = vshCmddefSearch(def->alias); return vshCmddefHelp(ctl, def); } else if ((grp = vshCmdGrpSearch(name))) { return vshCmdGrpHelp(ctl, grp); -- 2.13.6
On 01/25/2018 04:22 PM, Erik Skultety wrote:
The alias doesn't have any definition rather than a reference for the aliased command. Therefore when printing help, we have to print help for the aliased command, otherwise our faith is going to be met with SIGSEGV.
Erik Skultety (2): vsh: Drop redundant definition searches from vshCmd{def,Grp}Help vsh: Cmd aliases lookups should return results for the aliased command
tools/vsh.c | 45 +++++++++++++++++---------------------------- tools/vsh.h | 4 ++-- 2 files changed, 19 insertions(+), 30 deletions(-)
ACK series Michal
On Thu, Jan 25, 2018 at 04:49:38PM +0100, Michal Privoznik wrote:
On 01/25/2018 04:22 PM, Erik Skultety wrote:
The alias doesn't have any definition rather than a reference for the aliased command. Therefore when printing help, we have to print help for the aliased command, otherwise our faith is going to be met with SIGSEGV.
Erik Skultety (2): vsh: Drop redundant definition searches from vshCmd{def,Grp}Help vsh: Cmd aliases lookups should return results for the aliased command
tools/vsh.c | 45 +++++++++++++++++---------------------------- tools/vsh.h | 4 ++-- 2 files changed, 19 insertions(+), 30 deletions(-)
ACK series
Pushed, thanks. Erik
participants (2)
-
Erik Skultety -
Michal Privoznik