[RFA] driver: fix validate_switches logic
Commit Message
Tested x86_64-pc-linux-gnu, OK for trunk?
-- 8< --
Under the old logic for validate_switches, once suffix or starred got set,
they stayed set for all later switches found in the spec. So for e.g.
%{g*:%{%:debug-level-gt(0):
Once we see g*, starred is set. Then we see %:, and it sees that as a
zero-length switch, which because starred is still set, matches any and all
command-line options. So targets that use such a spec accept all options in
the driver, while ones that don't reject some, such as the recent
-nostdlib++.
This patch fixes the inconsistency, so all targets would complain about
-nostdlib++, and then sets SKIPOPT for it so they don't.
gcc/ChangeLog:
* gcc.cc (validate_switches): Reset suffix/starred on loop.
gcc/cp/ChangeLog:
* g++spec.cc (lang_specific_driver): Set SKIPOPT for nostdlib++.
---
gcc/cp/g++spec.cc | 4 +++-
gcc/gcc.cc | 7 +++++--
2 files changed, 8 insertions(+), 3 deletions(-)
base-commit: 4304e09a1617bcf1c87f5bc96017ae5017379d75
Comments
On Dec 1, 2022, Jason Merrill <jason@redhat.com> wrote:
> Once we see g*, starred is set. Then we see %:, and it sees that as a
> zero-length switch, which because starred is still set, matches any and all
> command-line options. So targets that use such a spec accept all options in
> the driver, while ones that don't reject some, such as the recent
> -nostdlib++.
Woo, nice catch, thanks!
I don't have authority to approve the patch,
but it's ok as far as I'm concerned.
On Fri, Dec 2, 2022 at 7:37 AM Alexandre Oliva via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Dec 1, 2022, Jason Merrill <jason@redhat.com> wrote:
>
> > Once we see g*, starred is set. Then we see %:, and it sees that as a
> > zero-length switch, which because starred is still set, matches any and all
> > command-line options. So targets that use such a spec accept all options in
> > the driver, while ones that don't reject some, such as the recent
> > -nostdlib++.
>
> Woo, nice catch, thanks!
>
> I don't have authority to approve the patch,
> but it's ok as far as I'm concerned.
OK.
> --
> Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
> Free Software Activist GNU Toolchain Engineer
> Disinformation flourishes because many people care deeply about injustice
> but very few check the facts. Ask me about <https://stallmansupport.org>
@@ -167,8 +167,10 @@ lang_specific_driver (struct cl_decoded_option **in_decoded_options,
need_experimental = true;
break;
- case OPT_nostdlib:
case OPT_nostdlib__:
+ args[i] |= SKIPOPT;
+ /* FALLTHRU */
+ case OPT_nostdlib:
case OPT_nodefaultlibs:
library = -1;
break;
@@ -9299,12 +9299,15 @@ validate_switches (const char *start, bool user_spec, bool braced)
const char *atom;
size_t len;
int i;
- bool suffix = false;
- bool starred = false;
+ bool suffix;
+ bool starred;
#define SKIP_WHITE() do { while (*p == ' ' || *p == '\t') p++; } while (0)
next_member:
+ suffix = false;
+ starred = false;
+
SKIP_WHITE ();
if (*p == '!')