On 3/10/23 11:17, Marek Polacek wrote:
We crash here since r10-3661, the store_init_value hunk in particular. Before, we called cp_fully_fold_init, so e.g.{.str=VIEW_CONVERT_EXPR<char[8]>("")} was folded into {.str=""} but now we don't fold and keep the VCE around, and it causes trouble in cxx_eval_store_expression: in the !refs->is_empty () loop we descend on .str's initializer but since it's wrapped in a VCE, we skip the STRING_CST check and then crash on the CONSTRUCTOR_NO_CLEARING. Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk/12? PR c++/107280 gcc/cp/ChangeLog: * constexpr.cc (cxx_eval_store_expression): Strip location wrappers. gcc/testsuite/ChangeLog: * g++.dg/cpp1z/constexpr-lambda28.C: New test. --- gcc/cp/constexpr.cc | 3 ++- gcc/testsuite/g++.dg/cpp1z/constexpr-lambda28.C | 15 +++++++++++++++ 2 files changed, 17 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp1z/constexpr-lambda28.C diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc index 8683c00596a..abf6ee560c5 100644 --- a/gcc/cp/constexpr.cc +++ b/gcc/cp/constexpr.cc @@ -6033,7 +6033,8 @@ cxx_eval_store_expression (const constexpr_ctx *ctx, tree t, *valp = build_constructor (type, NULL); CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; } - else if (TREE_CODE (*valp) == STRING_CST) + else if (STRIP_ANY_LOCATION_WRAPPER (*valp), + TREE_CODE (*valp) == STRING_CST)
Seems like this is stripping the location wrapper when we try to modify the string; I think we want to strip it earlier, when we first initialize the array member.
Jason
