https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103488
Bug ID: 103488
Summary: cpp --help lists some options that are silently
ignored
Product: gcc
Version: 11.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: preprocessor
Assignee: unassigned at gcc dot gnu.org
Reporter: adl at gnu dot org
Target Milestone: ---
Hi!
Sorry for this trivialish issue, but that puzzled me for 10 minutes this
morning while I was looking whether cpp had some option I needed.
The help text of cpp suggests that `cpp --help=common' will work, but that
option seems to be silently ignored.
% cpp --version | sed 1q
cpp (Debian 11.2.0-12) 11.2.0
% cpp --help | sed 7q
Usage: cpp [options] file...
Options:
-pass-exit-codes Exit with highest error code from a phase.
--help Display this information.
--target-help Display target specific command line options.
--help={common|optimizers|params|target|warnings|[^]{joined|separate|undocumented}}[,...].
Display specific types of command line options.
% cpp --help=common </dev/null
# 0 "<stdin>"
# 0 "<built-in>"
# 0 "<command-line>"
# 1 "/usr/include/stdc-predef.h" 1 3 4
# 0 "<command-line>" 2
# 1 "<stdin>"
% cpp --help=foobarbaz </dev/null
# 0 "<stdin>"
# 0 "<built-in>"
# 0 "<command-line>"
# 1 "/usr/include/stdc-predef.h" 1 3 4
# 0 "<command-line>" 2
# 1 "<stdin>"
Given this help text, I would have expected any use of --help=... to prevent
the normal behavior of cpp, and I would have expected a diagnostic for
--help=foobarbaz.
