Hi! The comment in the loop says that we shouldn't add a map clause if such a clause exists already, but the loop was actually using OMP_CLAUSE_DECL on any clause. Target construct can have various clauses which don't have OMP_CLAUSE_DECL at all (e.g. nowait, device or if) or clause where it means something different (e.g. privatization clauses, allocate, depend).
So, only check OMP_CLAUSE_DECL on OMP_CLAUSE_MAP clauses. Bootstrapped/regtested on x86_64-linux and i686-linux, committed to trunk so far. 2023-01-05 Jakub Jelinek <ja...@redhat.com> PR c++/108286 * semantics.cc (finish_omp_target_clauses): Ignore clauses other than OMP_CLAUSE_MAP. * testsuite/libgomp.c++/pr108286.C: New test. --- gcc/cp/semantics.cc.jj 2022-12-05 11:10:37.610673062 +0100 +++ gcc/cp/semantics.cc 2023-01-04 19:10:52.882277867 +0100 @@ -9825,7 +9825,9 @@ finish_omp_target_clauses (location_t lo for (tree c = *clauses_ptr; c; c = OMP_CLAUSE_CHAIN (c)) { - /* If map(this->ptr[:N] already exists, avoid creating another + if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_MAP) + continue; + /* If map(this->ptr[:N]) already exists, avoid creating another such map. */ tree decl = OMP_CLAUSE_DECL (c); if ((TREE_CODE (decl) == INDIRECT_REF --- libgomp/testsuite/libgomp.c++/pr108286.C.jj 2023-01-04 19:21:07.401384587 +0100 +++ libgomp/testsuite/libgomp.c++/pr108286.C 2023-01-04 19:20:05.793276171 +0100 @@ -0,0 +1,29 @@ +// PR c++/108286 +// { dg-do run } + +struct S { + int + foo () + { + int res = 0; +#pragma omp target map(size, ptr[:size], res) nowait + res = ptr[size - 1]; +#pragma omp taskwait + return res; + } + + unsigned size; + int *ptr; +}; + +int +main () +{ + S s; + int buf[5]; + s.size = 5; + s.ptr = buf; + buf[4] = 42; + if (s.foo () != 42) + __builtin_abort (); +} Jakub