Hi! The PR108503 temporary DECL_HAS_VALUE_EXPR_P clearing code can ICE during recovery, because cp_finish_decomp when it detects errors and reports them clears DECL_HAS_VALUE_EXPR_P, clears DECL_VALUE_EXPR and sets TREE_TYPE of the structured binding vars to error_mark_node. The PR108503 code had an assertion that DECL_HAS_VALUE_EXPR_P is set so that it can clear it and restore later.
The following patch allows DECL_HAS_VALUE_EXPR_P to be unset if type is error_mark_node and doesn't set it again in that case. Bootstrapped/regtested on x86_64-linux and i686-linux, committed to trunk. 2023-03-02 Jakub Jelinek <ja...@redhat.com> PR c++/105839 * parser.cc (cp_convert_omp_range_for): Allow in assert decomp_first_name without DECL_HAS_VALUE_EXPR_P if it has error_mark_node type. (cp_finish_omp_range_for): Don't set DECL_HAS_VALUE_EXPR_P back on decls which have error_mark_node type. * g++.dg/gomp/pr105839-1.C: New test. * g++.dg/gomp/pr105839-2.C: New test. --- gcc/cp/parser.cc.jj 2023-02-09 15:52:53.014025792 +0100 +++ gcc/cp/parser.cc 2023-03-01 12:20:59.970970342 +0100 @@ -43312,7 +43312,9 @@ cp_convert_omp_range_for (tree &this_pre name but the DECL_VALUE_EXPR will be dependent. Hide those from folding of other loop initializers e.g. for warning purposes until cp_finish_omp_range_for. */ - gcc_checking_assert (DECL_HAS_VALUE_EXPR_P (decomp_first_name)); + gcc_checking_assert (DECL_HAS_VALUE_EXPR_P (decomp_first_name) + || (TREE_TYPE (decomp_first_name) + == error_mark_node)); DECL_HAS_VALUE_EXPR_P (decomp_first_name) = 0; } TREE_VEC_ELT (v, i + 3) = decomp_first_name; @@ -43345,7 +43347,8 @@ cp_finish_omp_range_for (tree orig, tree tree d = decomp_first_name; for (unsigned i = 0; i < decomp_cnt; i++) { - DECL_HAS_VALUE_EXPR_P (d) = 1; + if (TREE_TYPE (d) != error_mark_node) + DECL_HAS_VALUE_EXPR_P (d) = 1; d = DECL_CHAIN (d); } } --- gcc/testsuite/g++.dg/gomp/pr105839-1.C.jj 2023-03-01 12:27:20.637439415 +0100 +++ gcc/testsuite/g++.dg/gomp/pr105839-1.C 2023-03-01 13:07:39.872273746 +0100 @@ -0,0 +1,25 @@ +// PR c++/105839 +// { dg-do compile { target c++11 } } +// { dg-options "-fopenmp" } + +template <typename T> +void +foo (const T &x) +{ + [&] (auto &&y) // { dg-error "use of 'auto' in lambda parameter declaration only available with" "" { target c++11_only } } + { + #pragma omp parallel for + for (auto &&[v1, v2] : x) // { dg-error "cannot decompose non-array non-class type 'const int'" } + ; // { dg-error "invalid type for iteration variable" "" { target c++14 } .-1 } + // { dg-warning "structured bindings only available with" "" { target c++14_down } .-2 } + } ([]{}); // { dg-error "no match for call to" "" { target c++11_only } } + // { dg-error "invalid user-defined conversion from" "" { target c++11_only } .-1 } + // { dg-error "invalid conversion from" "" { target c++11_only } .-2 } +} + +void +bar () +{ + int a[10]; + foo (a); +} --- gcc/testsuite/g++.dg/gomp/pr105839-2.C.jj 2023-03-01 13:07:26.192472845 +0100 +++ gcc/testsuite/g++.dg/gomp/pr105839-2.C 2023-03-01 13:07:48.475148529 +0100 @@ -0,0 +1,24 @@ +// PR c++/105839 +// { dg-do compile { target c++14 } } +// { dg-options "-fopenmp" } + +template <typename T> +void +foo (const T &x) +{ + [&] (auto &&y) + { + #pragma omp parallel for + for (auto &&[v1, v2] : x) // { dg-warning "structured bindings only available with" "" { target c++14_down } } + ; + } ([]{}); +} + +struct A { int a, b; }; + +void +bar () +{ + A a[10]; + foo (a); +} Jakub