On 11/25/24 4:46 PM, Marek Polacek wrote:
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk/14?-- >8 -- In a template, for union { union { T d; }; }; build_anon_union_vars crates a malformed COMPONENT_REF: we have no DECL_NAME for the nested anon union so we create something like "object.". Most of the front end doesn't seem to care, but if such a tree gets to potential_constant_expression, it can cause a crash. I suppose we can use any name for the COMPONENT_REF's member. tsubst_stmt should build up a proper one in: if (VAR_P (decl) && !DECL_NAME (decl) && ANON_AGGR_TYPE_P (TREE_TYPE (decl))) /* Anonymous aggregates are a special case. */ finish_anon_union (decl); PR c++/117153 gcc/cp/ChangeLog: * decl2.cc (build_anon_union_vars): If DECL_NAME is empty, use an anonymous name for the second operand of a COMPONENT_REF. gcc/testsuite/ChangeLog: * g++.dg/other/anon-union6.C: New test. * g++.dg/other/anon-union7.C: New test. --- gcc/cp/decl2.cc | 5 ++++- gcc/testsuite/g++.dg/other/anon-union6.C | 13 +++++++++++++ gcc/testsuite/g++.dg/other/anon-union7.C | 16 ++++++++++++++++ 3 files changed, 33 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/other/anon-union6.C create mode 100644 gcc/testsuite/g++.dg/other/anon-union7.C diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc index bc3a9d0e922..1383cbb660c 100644 --- a/gcc/cp/decl2.cc +++ b/gcc/cp/decl2.cc @@ -1959,7 +1959,10 @@ build_anon_union_vars (tree type, tree object)if (processing_template_decl)ref = build_min_nt_loc (UNKNOWN_LOCATION, COMPONENT_REF, object, - DECL_NAME (field), NULL_TREE); + (DECL_NAME (field) + ? DECL_NAME (field) + : make_anon_name ()), + NULL_TREE);
Why don't we use the field directly instead of its name, even for named fields?
Jason
