| Message ID | 20191227163224.4113837-6-george.dunlap@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/9] golang/xenlight: Don't try to marshall zero-length arrays | expand |
On Fri, Dec 27, 2019 at 11:33 AM George Dunlap <george.dunlap@citrix.com> wrote: > > Commit 871e51d2d4 changed the sign on the xenlight error types (making > the values negative, same as the C-generated constants), but failed to > flip the sign in the Error() string function. The result is that > ErrorNonspecific.String() prints "libxl error: 1" rather than the > human-readable error message. Since we're here, what would you think about re-defining libxlErrors as a map[Error]string? That way, Error() can just be: func (e Error) Error() string { if s, ok := libxlErrors[e]; ok { return s } return fmt.Sprintf("libxl error: %d", e) } I think it's less error-prone and easier to read. Thoughts? -NR
On 1/4/20 7:27 PM, Nick Rosbrook wrote: > On Fri, Dec 27, 2019 at 11:33 AM George Dunlap <george.dunlap@citrix.com> wrote: >> >> Commit 871e51d2d4 changed the sign on the xenlight error types (making >> the values negative, same as the C-generated constants), but failed to >> flip the sign in the Error() string function. The result is that >> ErrorNonspecific.String() prints "libxl error: 1" rather than the >> human-readable error message. > > Since we're here, what would you think about re-defining libxlErrors > as a map[Error]string? That way, Error() can just be: > > func (e Error) Error() string { > if s, ok := libxlErrors[e]; ok { > return s > } > > return fmt.Sprintf("libxl error: %d", e) > } > > I think it's less error-prone and easier to read. Thoughts? Yes, that sounds better. Done. -George
diff --git a/tools/golang/xenlight/xenlight.go b/tools/golang/xenlight/xenlight.go index 99de68320b..c80f622e6b 100644 --- a/tools/golang/xenlight/xenlight.go +++ b/tools/golang/xenlight/xenlight.go @@ -65,13 +65,14 @@ var libxlErrors = [...]string{ } func (e Error) Error() string { - if 0 < int(e) && int(e) < len(libxlErrors) { - s := libxlErrors[e] + eidx := -int(e) + if 0 < eidx && eidx < len(libxlErrors) { + s := libxlErrors[eidx] if s != "" { return s } } - return fmt.Sprintf("libxl error: %d", -e) + return fmt.Sprintf("libxl error: %d", e) } // Context represents a libxl_ctx.
Commit 871e51d2d4 changed the sign on the xenlight error types (making the values negative, same as the C-generated constants), but failed to flip the sign in the Error() string function. The result is that ErrorNonspecific.String() prints "libxl error: 1" rather than the human-readable error message. Get the error message index by inverting the error number once. Also, always print the actual error value, rather than the inverted value, for clarity. Signed-off-by: George Dunlap <george.dunlap@citrix.com> --- CC: Nick Rosbrook <rosbrookn@ainfosec.com> --- tools/golang/xenlight/xenlight.go | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)