On Jul 13, 2021, Alexandre Oliva <ol...@adacore.com> wrote:
> On Jul 13, 2021, Richard Biener <richard.guent...@gmail.com> wrote:
>> oops - also worth backporting to affected branches.
> Thanks, I took that as explicit approval and put it in.
> attr fnspec is new in gcc-11, not present in gcc-10, so I'm testing a
> trivial backport, just to be sure... Will install in gcc-11 when done.
Here's what I've just installed.
fix typo in attr_fnspec::verify
Odd-numbered indices describing argument access sizes in the fnspec
string can only hold 't' or a digit, as tested in the beginning of the
case. When checking that the size-supplying argument does not have
additional information associated with it, the test that excludes the
't' possibility looks for it at the even position in the fnspec
string. Oops.
This might yield false positives and negatives if a function has a
fnspec in which an argument uses a 't' access-size, and ('t' - '1')
happens to be the index of an argument described in an fnspec string.
Assuming ASCII encoding, it would take a function with at least 68
arguments described in fnspec. Still, probably worth fixing.
for gcc/ChangeLog
* tree-ssa-alias.c (attr_fnspec::verify): Fix index in
non-'t'-sized arg check.
(cherry picked from commit a7098d6ef4e4e799dab8ef925c62b199d707694b)
---
gcc/tree-ssa-alias.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index ebb3f49c86c66..3e578e5d05f49 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -3868,7 +3868,7 @@ attr_fnspec::verify ()
&& str[idx] != 'w' && str[idx] != 'W'
&& str[idx] != 'o' && str[idx] != 'O')
err = true;
- if (str[idx] != 't'
+ if (str[idx + 1] != 't'
/* Size specified is scalar, so it should be described
by ". " if specified at all. */
&& (arg_specified_p (str[idx + 1] - '1')
--
Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
Free Software Activist GNU Toolchain Engineer
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