diff mbox series

[RFA] driver: fix validate_switches logic

Message ID 20221201165051.51853-1-jason@redhat.com
State Accepted
Headers
Series [RFA] driver: fix validate_switches logic |

Checks

Context Check Description
snail/gcc-patch-check success Github commit url

Commit Message

Jason Merrill Dec. 1, 2022, 4:50 p.m. UTC 
  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

Alexandre Oliva Dec. 2, 2022, 6:36 a.m. UTC | #1 
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.
Richard Biener Dec. 2, 2022, 7:50 a.m. UTC | #2 
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>
diff mbox series

Patch

diff --git a/gcc/cp/g++spec.cc b/gcc/cp/g++spec.cc
index e599ac906f6..3d3b042dd56 100644
--- a/gcc/cp/g++spec.cc
+++ b/gcc/cp/g++spec.cc
@@ -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;
diff --git a/gcc/gcc.cc b/gcc/gcc.cc
index ca1c9e27a94..2278e2b6bb1 100644
--- a/gcc/gcc.cc
+++ b/gcc/gcc.cc
@@ -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 == '!')