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. Regstrapped on x86_64-linux-gnu. I'm checking this in as obvious unless there are objections within some 48 hours. for gcc/ChangeLog * tree-ssa-alias.c (attr_fnspec::verify): Fix index in non-'t'-sized arg check. --- 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 0421bfac99869..742a95a549e20 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -3895,7 +3895,7 @@ 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 Disinformation flourishes because many people care deeply about injustice but very few check the facts. Ask me about <https://stallmansupport.org>