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| author | Patrick Palka <ppalka@redhat.com> | 2022-06-07 14:19:53 -0400 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2022-09-12 17:05:34 -0400 |
| commit | c3ba0eaaa223f7b8208d279e3f39ff134912f9e9 (patch) | |
| tree | 7053a8ee00c8cae538a5c5a6f7d7559482972224 /gcc/cp | |
| parent | 03381beccb52c0e2c15da3b8b8dfa3bb6eb71df9 (diff) | |
| download | gcc-c3ba0eaaa223f7b8208d279e3f39ff134912f9e9.zip gcc-c3ba0eaaa223f7b8208d279e3f39ff134912f9e9.tar.gz gcc-c3ba0eaaa223f7b8208d279e3f39ff134912f9e9.tar.bz2 | |
c++: template-id arguments are evaluated [PR101906]
Here we're neglecting to clear cp_unevaluated_operand when substituting
into the arguments of the alias template-id 'skip<(T(), 0), T>' with T=A,
which means cp_unevaluated_operand remains set during mark_used for
A::A() and so we don't synthesize it. Later constant evaluation for
the substituted template argument '(A(), 0)' (from coerce_template_parms)
fails with "'constexpr A::A()' used before its definition" since it was
never synthesized.
This doesn't happen with a class template because tsubst_aggr_type
clears cp_unevaluated_operand during substitution thereof. But since
template arguments are generally manifestly constant-evaluated, which in
turn are evaluated even in an unevaluated operand, we should be clearing
cp_unevaluated_operand more broadly whenever substituting into any set
of template arguments. To that end this patch makes us clear it during
tsubst_template_args.
PR c++/101906
gcc/cp/ChangeLog:
* pt.cc (tsubst_template_args): Set cp_evaluated here.
(tsubst_aggr_type): Not here.
gcc/testsuite/ChangeLog:
* g++.dg/template/evaluated1.C: New test.
* g++.dg/template/evaluated1a.C: New test.
* g++.dg/template/evaluated1b.C: New test.
* g++.dg/template/evaluated1c.C: New test.
Diffstat (limited to 'gcc/cp')
| -rw-r--r-- | gcc/cp/pt.cc | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 31e3e39..4c6b343 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -13616,6 +13616,9 @@ tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl) if (t == error_mark_node) return error_mark_node; + /* In "sizeof(X<I>)" we need to evaluate "I". */ + cp_evaluated ev; + const int len = TREE_VEC_LENGTH (t); tree *elts = XALLOCAVEC (tree, len); int expanded_len_adjust = 0; @@ -13888,9 +13891,6 @@ tsubst_aggr_type (tree t, tree argvec; tree r; - /* In "sizeof(X<I>)" we need to evaluate "I". */ - cp_evaluated ev; - /* Figure out what arguments are appropriate for the type we are trying to find. For example, given: |