https://gcc.gnu.org/g:38dc98d81ed0d673d648031732f84f807ce24eb3
commit r16-8910-g38dc98d81ed0d673d648031732f84f807ce24eb3 Author: Jakub Jelinek <[email protected]> Date: Thu May 7 08:54:21 2026 +0200 c++: Fix up extract_ref [PR125111] https://eel.is/c++draft/meta.reflection.extract#5.2 requests that is_convertible_v<remove_reference_t<U>(*)[], remove_reference_t<T>(*)[]> is tested and if it not true, the function throws. If U/T are references to function/method/array[], we try to build array of types which are not valid in arrays and ICE shortly after that. The following patch makes sure we don't create arrays in that case and instead just throw the exception. We can't have references to void or references to references, so I think the other problematic cases of creating arrays can't trigger. 2026-05-07 Jakub Jelinek <[email protected]> PR c++/125111 * reflect.cc (extract_ref): Throw instead of trying to build arrays of functions, methods or arrays with NULL TYPE_DOMAIN. * g++.dg/reflect/extract12.C: New test. Reviewed-by: Jason Merrill <[email protected]> (cherry picked from commit ef48b322cd98e23de57ad0d8f09ec02aa97d40c4) Diff: --- gcc/cp/reflect.cc | 10 +++++++++- gcc/testsuite/g++.dg/reflect/extract12.C | 14 ++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/gcc/cp/reflect.cc b/gcc/cp/reflect.cc index 2be4ba6d2a8e..9bbbd06aa7f1 100644 --- a/gcc/cp/reflect.cc +++ b/gcc/cp/reflect.cc @@ -7458,6 +7458,10 @@ extract_ref (location_t loc, const constexpr_ctx *ctx, tree T, tree r, { if (TYPE_REF_P (type)) type = TREE_TYPE (type); + if (FUNC_OR_METHOD_TYPE_P (type) + || (TREE_CODE (type) == ARRAY_TYPE + && TYPE_DOMAIN (type) == NULL_TREE)) + return error_mark_node; type = build_cplus_array_type (type, NULL_TREE); return build_pointer_type (type); }; @@ -7467,7 +7471,11 @@ extract_ref (location_t loc, const constexpr_ctx *ctx, tree T, tree r, { /* The wording is saying that U is the type of r. */ tree U = TREE_TYPE (r); - if (is_convertible (adjust_type (U), adjust_type (T)) + tree adju = adjust_type (U); + tree adjt = adjust_type (T); + if (adju != error_mark_node + && adjt != error_mark_node + && is_convertible (adju, adjt) && (!var_p || is_constant_expression (r))) { if (TYPE_REF_P (TREE_TYPE (r))) diff --git a/gcc/testsuite/g++.dg/reflect/extract12.C b/gcc/testsuite/g++.dg/reflect/extract12.C new file mode 100644 index 000000000000..cc5c856e754b --- /dev/null +++ b/gcc/testsuite/g++.dg/reflect/extract12.C @@ -0,0 +1,14 @@ +// PR c++/125111 +// { dg-do compile { target c++26 } } +// { dg-additional-options "-freflection" } + +#include <meta> + +using A = void (); +extern A &a; +constexpr auto b = ^^a; +constexpr auto c = std::meta::extract <A &> (b); // { dg-error "uncaught exception of type 'std::meta::exception'; 'what\\\(\\\)': 'value cannot be extracted'" } +using B = int []; +extern B &d; +constexpr auto e = ^^d; +constexpr auto f = std::meta::extract <B &> (e); // { dg-error "uncaught exception of type 'std::meta::exception'; 'what\\\(\\\)': 'value cannot be extracted'" }
