Here we're mishandling the unevaluated array new-expressions due to a supposed non-constant array size ever since r12-5253-g4df7f8c79835d569, made us no longer perform constant evaluation of non-manifestly-constant expressions within unevaluated contexts. This shouldn't make a difference here since the array sizes are constant literals, except they're actually NON_LVALUE_EXPR location wrappers wrapping INTEGER_CST, wrappers which used to get stripped as part of constant evaluation and now no longer do. Moreover it means build_vec_init can't constant fold the 'maxindex' passed from build_new_1 (since it uses maybe_constant_value with mce_unknown).
This patch fixes the first issue by making maybe_constant_value and fold_non_dependent_expr_template shortcut handling location wrappers around constant nodes, and the second issue by using fold_build2_loc instead of cp_build_binary_op when computing the maxindex to pass to build_vec_init. Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk/12? PR c++/108219 PR c++/108218 gcc/cp/ChangeLog: * constexpr.cc (maybe_constant_value): Extend the constant node shortcut to look through location wrappers too. (fold_non_dependent_expr_template): Mirror the constant node shortcut from maybe_constant_value. * init.cc (build_new_1): Use fold_build2_loc instead of cp_build_binary_op to build a MINUS_EXPR representing the maximum index. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/new6.C: New test. * g++.dg/cpp2a/concepts-new1.C: New test. --- gcc/cp/constexpr.cc | 8 ++++++-- gcc/cp/init.cc | 18 ++++++++---------- gcc/testsuite/g++.dg/cpp0x/new6.C | 9 +++++++++ gcc/testsuite/g++.dg/cpp2a/concepts-new1.C | 13 +++++++++++++ 4 files changed, 36 insertions(+), 12 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/new6.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-new1.C diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc index aa2c14355f8..d38c4c80415 100644 --- a/gcc/cp/constexpr.cc +++ b/gcc/cp/constexpr.cc @@ -8538,9 +8538,9 @@ maybe_constant_value (tree t, tree decl /* = NULL_TREE */, t = mark_non_constant (t); return t; } - else if (CONSTANT_CLASS_P (t)) + else if (CONSTANT_CLASS_OR_WRAPPER_P (t)) /* No caching or evaluation needed. */ - return t; + return tree_strip_any_location_wrapper (t); if (manifestly_const_eval != mce_unknown) return cxx_eval_outermost_constant_expr (t, true, true, @@ -8631,6 +8631,10 @@ fold_non_dependent_expr_template (tree t, tsubst_flags_t complain, return t; } + if (CONSTANT_CLASS_OR_WRAPPER_P (t)) + /* No evaluation needed. */ + return tree_strip_any_location_wrapper (t); + if (cp_unevaluated_operand && !manifestly_const_eval) return t; diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc index 705a5b3bdb6..574d2e2586c 100644 --- a/gcc/cp/init.cc +++ b/gcc/cp/init.cc @@ -3653,16 +3653,14 @@ build_new_1 (vec<tree, va_gc> **placement, tree type, tree nelts, error ("parenthesized initializer in array new"); return error_mark_node; } - init_expr - = build_vec_init (data_addr, - cp_build_binary_op (input_location, - MINUS_EXPR, outer_nelts, - integer_one_node, - complain), - vecinit, - explicit_value_init_p, - /*from_array=*/0, - complain); + tree maxindex = fold_build2_loc (input_location, MINUS_EXPR, + TREE_TYPE (outer_nelts), + outer_nelts, + build_one_cst (TREE_TYPE + (outer_nelts))); + init_expr = build_vec_init (data_addr, maxindex, vecinit, + explicit_value_init_p, /*from_array=*/0, + complain); } else { diff --git a/gcc/testsuite/g++.dg/cpp0x/new6.C b/gcc/testsuite/g++.dg/cpp0x/new6.C new file mode 100644 index 00000000000..17a669b42d0 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/new6.C @@ -0,0 +1,9 @@ +// PR c++/108218 +// { dg-do compile { target c++11 } } + +template<class T> +void f() { + decltype(new int[-1]) p; // { dg-error "negative" } +} + +decltype(new int[-1]) q; // { dg-error "negative" } diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-new1.C b/gcc/testsuite/g++.dg/cpp2a/concepts-new1.C new file mode 100644 index 00000000000..62007205108 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-new1.C @@ -0,0 +1,13 @@ +// PR c++/108219 +// { dg-do compile { target c++20 } } + +template<class T> +concept C = requires { new T[1]{{ 42 }}; }; + +template<class T> +concept D = requires { new T[2][1]{{{ 42 }}, {{ 42 }}}; }; + +struct A { A(int); }; + +static_assert(C<A>); +static_assert(D<A>); -- 2.39.2.501.gd9d677b2d8