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| author | Patrick Palka <ppalka@redhat.com> | 2023-07-11 10:05:19 -0400 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2023-07-11 10:05:19 -0400 |
| commit | b76d71564925abcabe6f5ad61d904b23c682cdfb (patch) | |
| tree | a86ab08219e4a241361e1dd4aaacb511c5919c96 | |
| parent | e5c64efb1367459dbc2d2e29856f23908cb503c1 (diff) | |
| download | gcc-b76d71564925abcabe6f5ad61d904b23c682cdfb.zip gcc-b76d71564925abcabe6f5ad61d904b23c682cdfb.tar.gz gcc-b76d71564925abcabe6f5ad61d904b23c682cdfb.tar.bz2 | |
c++: coercing variable template from current inst [PR110580]
Here during ahead of time coercion of the variable template-id v1<int>,
since we pass only the innermost arguments to coerce_template_parms (and
outer arguments are still dependent at this point), substitution of the
default template argument V=U just lowers U from level 2 to level 1 rather
than replacing it with int as expected. Thus after coercion we incorrectly
end up with (effectively) v1<int, T> instead of v1<int, int>.
Coercion of a class/alias template-id on the other hand always passes
all levels arguments, which avoids this issue. So this patch makes us
do the same for variable template-ids.
PR c++/110580
gcc/cp/ChangeLog:
* pt.cc (lookup_template_variable): Pass all levels of arguments
to coerce_template_parms, and use the parameters from the most
general template.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/var-templ83.C: New test.
| -rw-r--r-- | gcc/cp/pt.cc | 4 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp1y/var-templ83.C | 16 |
2 files changed, 19 insertions, 1 deletions
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 076f788..fa15b75 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -10345,7 +10345,9 @@ lookup_template_variable (tree templ, tree arglist, tsubst_flags_t complain) if (flag_concepts && variable_concept_p (templ)) return build_concept_check (templ, arglist, tf_none); - tree parms = DECL_INNERMOST_TEMPLATE_PARMS (templ); + tree gen_templ = most_general_template (templ); + tree parms = DECL_INNERMOST_TEMPLATE_PARMS (gen_templ); + arglist = add_outermost_template_args (templ, arglist); arglist = coerce_template_parms (parms, arglist, templ, complain); if (arglist == error_mark_node) return error_mark_node; diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ83.C b/gcc/testsuite/g++.dg/cpp1y/var-templ83.C new file mode 100644 index 0000000..f5268f2 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ83.C @@ -0,0 +1,16 @@ +// PR c++/110580 +// { dg-do compile { target c++14 } } + +template<class T> +struct A { + template<typename U, typename V = U> + static constexpr bool v1 = __is_same(U, V); + + template<typename U, typename V = T> + static constexpr bool v2 = !__is_same(U, V); + + static_assert(v1<int>, ""); + static_assert(v2<int>, ""); +}; + +template struct A<char>; |