From 6851e3423c2b5ec6516efa0677745d25c905e079 Mon Sep 17 00:00:00 2001 From: Marek Polacek Date: Thu, 31 Aug 2023 20:11:50 -0400 Subject: [PATCH] c++: Move consteval folding to cp_fold_r In the review of P2564: it turned out that in order to correctly handle an example in the paper, we should stop doing immediate evaluation in build_over_call and bot_replace, and instead do it in cp_fold_r. This patch does that. Another benefit is that this is a pretty significant simplification, at least in my opinion. Also, this fixes the c++/110997 ICE (but the test doesn't compile yet). The main drawback seems to be that cp_fold_r doesn't process uninstantiated templates. We still have to handle things like "false ? foo () : 1". To that end, I've added cp_fold_immediate, called on dead branches in cxx_eval_conditional_expression. You'll see that I've reintroduced ADDR_EXPR_DENOTES_CALL_P here. This is to detect *(&foo)) () (s.*&S::foo) () which were deemed ill-formed. gcc/cp/ChangeLog: * call.cc (build_over_call): Set ADDR_EXPR_DENOTES_CALL_P. Don't handle immediate_invocation_p here. * constexpr.cc (cxx_eval_call_expression): Use mce_true for DECL_IMMEDIATE_FUNCTION_P. (cxx_eval_conditional_expression): Call cp_fold_immediate. * cp-gimplify.cc (enum fold_flags): Add ff_fold_immediate. (maybe_replace_decl): Make static. (cp_fold_r): Expand immediate invocations. (cp_fold_immediate_r): New. (cp_fold_immediate): New. * cp-tree.h (ADDR_EXPR_DENOTES_CALL_P): Define. (cp_fold_immediate): Declare. * tree.cc (bot_replace): Don't handle immediate invocations here. libstdc++-v3/ChangeLog: * testsuite/20_util/allocator/105975.cc: Add dg-error. gcc/testsuite/ChangeLog: * g++.dg/cpp23/consteval-if2.C: Add xfail. * g++.dg/cpp2a/consteval-memfn1.C: Adjust. * g++.dg/cpp2a/consteval11.C: Remove dg-message. * g++.dg/cpp2a/consteval3.C: Remove dg-message and dg-error. * g++.dg/cpp2a/consteval9.C: Remove dg-message. * g++.dg/cpp2a/consteval32.C: New test. * g++.dg/cpp2a/consteval33.C: New test. * g++.dg/cpp2a/consteval34.C: New test. * g++.dg/cpp2a/consteval35.C: New test. --- gcc/cp/call.cc | 40 +---- gcc/cp/constexpr.cc | 23 ++- gcc/cp/cp-gimplify.cc | 161 ++++++++++++++---- gcc/cp/cp-tree.h | 42 +++-- gcc/cp/tree.cc | 23 +-- gcc/testsuite/g++.dg/cpp23/consteval-if2.C | 3 +- gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C | 7 + gcc/testsuite/g++.dg/cpp2a/consteval11.C | 33 ++-- gcc/testsuite/g++.dg/cpp2a/consteval3.C | 3 +- gcc/testsuite/g++.dg/cpp2a/consteval32.C | 4 + gcc/testsuite/g++.dg/cpp2a/consteval33.C | 34 ++++ gcc/testsuite/g++.dg/cpp2a/consteval34.C | 33 ++++ gcc/testsuite/g++.dg/cpp2a/consteval35.C | 10 ++ gcc/testsuite/g++.dg/cpp2a/consteval9.C | 3 +- .../testsuite/20_util/allocator/105975.cc | 2 +- 15 files changed, 288 insertions(+), 133 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval32.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval33.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval34.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval35.C diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc index 2bbaeee039d..e8dafbd8ba6 100644 --- a/gcc/cp/call.cc +++ b/gcc/cp/call.cc @@ -10434,6 +10434,10 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) fn = build_addr_func (fn, complain); if (fn == error_mark_node) return error_mark_node; + + /* We're actually invoking the function. (Immediate functions get an + & when invoking it even though the user didn't use &.) */ + ADDR_EXPR_DENOTES_CALL_P (fn) = true; } tree call = build_cxx_call (fn, nargs, argarray, complain|decltype_flag); @@ -10451,41 +10455,7 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) if (TREE_CODE (c) == CALL_EXPR) suppress_warning (c /* Suppress all warnings. */); } - if (TREE_CODE (fn) == ADDR_EXPR) - { - tree fndecl = STRIP_TEMPLATE (TREE_OPERAND (fn, 0)); - if (immediate_invocation_p (fndecl)) - { - tree obj_arg = NULL_TREE; - /* Undo convert_from_reference called by build_cxx_call. */ - if (REFERENCE_REF_P (call)) - call = TREE_OPERAND (call, 0); - if (DECL_CONSTRUCTOR_P (fndecl)) - obj_arg = cand->first_arg ? cand->first_arg : (*args)[0]; - if (obj_arg && is_dummy_object (obj_arg)) - { - call = build_cplus_new (DECL_CONTEXT (fndecl), call, complain); - obj_arg = NULL_TREE; - } - /* Look through *(const T *)&obj. */ - else if (obj_arg && INDIRECT_REF_P (obj_arg)) - { - tree addr = TREE_OPERAND (obj_arg, 0); - STRIP_NOPS (addr); - if (TREE_CODE (addr) == ADDR_EXPR) - { - tree typeo = TREE_TYPE (obj_arg); - tree typei = TREE_TYPE (TREE_OPERAND (addr, 0)); - if (same_type_ignoring_top_level_qualifiers_p (typeo, typei)) - obj_arg = TREE_OPERAND (addr, 0); - } - } - call = cxx_constant_value (call, obj_arg, complain); - if (obj_arg && !error_operand_p (call)) - call = cp_build_init_expr (obj_arg, call); - call = convert_from_reference (call); - } - } + return call; } diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc index 0ca4370deab..a673a6022f1 100644 --- a/gcc/cp/constexpr.cc +++ b/gcc/cp/constexpr.cc @@ -3135,6 +3135,11 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, unsigned save_heap_alloc_count = ctx->global->heap_vars.length (); unsigned save_heap_dealloc_count = ctx->global->heap_dealloc_count; + /* Make sure we fold std::is_constant_evaluated to true in an + immediate function. */ + if (DECL_IMMEDIATE_FUNCTION_P (fun)) + call_ctx.manifestly_const_eval = mce_true; + /* If this is a constexpr destructor, the object's const and volatile semantics are no longer in effect; see [class.dtor]p5. */ if (new_obj && DECL_DESTRUCTOR_P (fun)) @@ -3807,8 +3812,7 @@ cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t, } /* Subroutine of cxx_eval_constant_expression. - Attempt to evaluate condition expressions. Dead branches are not - looked into. */ + Attempt to evaluate condition expressions. */ static tree cxx_eval_conditional_expression (const constexpr_ctx *ctx, tree t, @@ -3837,12 +3841,25 @@ cxx_eval_conditional_expression (const constexpr_ctx *ctx, tree t, boolean_type_node); } /* Don't VERIFY_CONSTANT the other operands. */ - if (integer_zerop (val)) + const bool zero_p = integer_zerop (val); + if (zero_p) val = TREE_OPERAND (t, 2); else val = TREE_OPERAND (t, 1); if (TREE_CODE (t) == IF_STMT && !val) val = void_node; + + /* P2564: a subexpression of a manifestly constant-evaluated expression + or conversion is an immediate function context. */ + if (ctx->manifestly_const_eval != mce_true + && !in_immediate_context () + && cp_fold_immediate (&TREE_OPERAND (t, zero_p ? 1 : 2), + ctx->manifestly_const_eval)) + { + *non_constant_p = true; + return t; + } + /* A TARGET_EXPR may be nested inside another TARGET_EXPR, but still serve as the initializer for the same object as the outer TARGET_EXPR, as in diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc index 206e791fcfd..bdf6e5f98ff 100644 --- a/gcc/cp/cp-gimplify.cc +++ b/gcc/cp/cp-gimplify.cc @@ -53,6 +53,8 @@ enum fold_flags { definitely not in a manifestly constant-evaluated context. */ ff_mce_false = 1 << 1, + /* Whether we're being called from cp_fold_immediate. */ + ff_fold_immediate = 1 << 2, }; using fold_flags_t = int; @@ -1000,7 +1002,7 @@ cp_genericize_target_expr (tree *stmt_p) replacement when cp_folding TARGET_EXPR to preserve the invariant that AGGR_INIT_EXPR_SLOT agrees with the enclosing TARGET_EXPR_SLOT. */ -bool +static bool maybe_replace_decl (tree *tp, tree decl, tree replacement) { if (!*tp || !VOID_TYPE_P (TREE_TYPE (*tp))) @@ -1029,6 +1031,123 @@ struct cp_genericize_data bool handle_invisiref_parm_p; }; +/* A subroutine of cp_fold_r to handle immediate functions. */ + +static tree +cp_fold_immediate_r (tree *stmt_p, int *walk_subtrees, void *data_) +{ + auto data = static_cast(data_); + tree stmt = *stmt_p; + /* The purpose of this is not to emit errors for mce_unknown. */ + const tsubst_flags_t complain = (data->flags & ff_mce_false + ? tf_error : tf_none); + + /* No need to look into types or unevaluated operands. + NB: This affects cp_fold_r as well. */ + if (TYPE_P (stmt) || unevaluated_p (TREE_CODE (stmt))) + { + *walk_subtrees = 0; + return NULL_TREE; + } + + switch (TREE_CODE (stmt)) + { + /* Unfortunately we must handle code like + false ? bar () : 42 + where we have to check bar too. The cp_fold call in cp_fold_r could + fold the ?: into a constant before we see it here. */ + case COND_EXPR: + /* If we are called from cp_fold_immediate, we don't need to worry about + cp_fold folding away the COND_EXPR. */ + if (data->flags & ff_fold_immediate) + break; + if (TREE_OPERAND (stmt, 1) + && cp_walk_tree (&TREE_OPERAND (stmt, 1), cp_fold_immediate_r, data, + nullptr)) + return error_mark_node; + if (TREE_OPERAND (stmt, 2) + && cp_walk_tree (&TREE_OPERAND (stmt, 2), cp_fold_immediate_r, data, + nullptr)) + return error_mark_node; + /* We're done here. Don't clear *walk_subtrees here though: we're called + from cp_fold_r and we must let it recurse on the expression with + cp_fold. */ + break; + case PTRMEM_CST: + if (TREE_CODE (PTRMEM_CST_MEMBER (stmt)) == FUNCTION_DECL + && DECL_IMMEDIATE_FUNCTION_P (PTRMEM_CST_MEMBER (stmt))) + { + if (!data->pset.add (stmt) && (complain & tf_error)) + { + error_at (PTRMEM_CST_LOCATION (stmt), + "taking address of an immediate function %qD", + PTRMEM_CST_MEMBER (stmt)); + *stmt_p = build_zero_cst (TREE_TYPE (stmt)); + } + return error_mark_node; + } + break; + + /* Expand immediate invocations. */ + case CALL_EXPR: + case AGGR_INIT_EXPR: + if (tree fn = cp_get_callee (stmt)) + if (TREE_CODE (fn) != ADDR_EXPR || ADDR_EXPR_DENOTES_CALL_P (fn)) + if (tree fndecl = cp_get_fndecl_from_callee (fn, /*fold*/false)) + if (DECL_IMMEDIATE_FUNCTION_P (fndecl)) + { + stmt = cxx_constant_value (stmt, complain); + if (stmt == error_mark_node) + { + if (complain & tf_error) + *stmt_p = error_mark_node; + return error_mark_node; + } + *stmt_p = stmt; + } + break; + + case ADDR_EXPR: + if (TREE_CODE (TREE_OPERAND (stmt, 0)) == FUNCTION_DECL + && DECL_IMMEDIATE_FUNCTION_P (TREE_OPERAND (stmt, 0)) + && !ADDR_EXPR_DENOTES_CALL_P (stmt)) + { + if (complain & tf_error) + { + error_at (EXPR_LOCATION (stmt), + "taking address of an immediate function %qD", + TREE_OPERAND (stmt, 0)); + *stmt_p = build_zero_cst (TREE_TYPE (stmt)); + } + return error_mark_node; + } + break; + + default: + break; + } + + return NULL_TREE; +} + +/* A wrapper around cp_fold_immediate_r. Return true if we found + a non-constant immediate function, or taking the address of an + immediate function. */ + +bool +cp_fold_immediate (tree *tp, mce_value manifestly_const_eval) +{ + if (cxx_dialect <= cxx17) + return false; + + fold_flags_t flags = ff_fold_immediate; + if (manifestly_const_eval == mce_false) + flags |= ff_mce_false; + + cp_fold_data data (flags); + return !!cp_walk_tree_without_duplicates (tp, cp_fold_immediate_r, &data); +} + /* Perform any pre-gimplification folding of C++ front end trees to GENERIC. Note: The folding of non-omp cases is something to move into @@ -1043,36 +1162,8 @@ cp_fold_r (tree *stmt_p, int *walk_subtrees, void *data_) tree stmt = *stmt_p; enum tree_code code = TREE_CODE (stmt); - switch (code) - { - case PTRMEM_CST: - if (TREE_CODE (PTRMEM_CST_MEMBER (stmt)) == FUNCTION_DECL - && DECL_IMMEDIATE_FUNCTION_P (PTRMEM_CST_MEMBER (stmt))) - { - if (!data->pset.add (stmt)) - error_at (PTRMEM_CST_LOCATION (stmt), - "taking address of an immediate function %qD", - PTRMEM_CST_MEMBER (stmt)); - stmt = *stmt_p = build_zero_cst (TREE_TYPE (stmt)); - break; - } - break; - - case ADDR_EXPR: - if (TREE_CODE (TREE_OPERAND (stmt, 0)) == FUNCTION_DECL - && DECL_IMMEDIATE_FUNCTION_P (TREE_OPERAND (stmt, 0))) - { - error_at (EXPR_LOCATION (stmt), - "taking address of an immediate function %qD", - TREE_OPERAND (stmt, 0)); - stmt = *stmt_p = build_zero_cst (TREE_TYPE (stmt)); - break; - } - break; - - default: - break; - } + if (cxx_dialect > cxx17) + cp_fold_immediate_r (stmt_p, walk_subtrees, data); *stmt_p = stmt = cp_fold (*stmt_p, data->flags); @@ -1084,7 +1175,7 @@ cp_fold_r (tree *stmt_p, int *walk_subtrees, void *data_) always the same tree, which the first time cp_fold_r has been called on it had the subtrees walked. */ *walk_subtrees = 0; - return NULL; + return NULL_TREE; } code = TREE_CODE (stmt); @@ -1136,7 +1227,7 @@ cp_fold_r (tree *stmt_p, int *walk_subtrees, void *data_) } cp_walk_tree (&OMP_FOR_PRE_BODY (stmt), cp_fold_r, data, NULL); *walk_subtrees = 0; - return NULL; + return NULL_TREE; case IF_STMT: if (IF_STMT_CONSTEVAL_P (stmt)) @@ -1146,7 +1237,7 @@ cp_fold_r (tree *stmt_p, int *walk_subtrees, void *data_) cp_walk_tree (&ELSE_CLAUSE (stmt), cp_fold_r, data, NULL); cp_walk_tree (&IF_SCOPE (stmt), cp_fold_r, data, NULL); *walk_subtrees = 0; - return NULL; + return NULL_TREE; } break; @@ -1183,7 +1274,7 @@ cp_fold_r (tree *stmt_p, int *walk_subtrees, void *data_) break; } - return NULL; + return NULL_TREE; } /* Fold ALL the trees! FIXME we should be able to remove this, but diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index 3ca011c61c8..5084932633a 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -4784,6 +4784,11 @@ get_vec_init_expr (tree t) #define PTRMEM_OK_P(NODE) \ TREE_LANG_FLAG_0 (TREE_CHECK3 ((NODE), ADDR_EXPR, OFFSET_REF, SCOPE_REF)) +/* True if this ADDR_EXPR denotes a function call; that is, it's + fn() rather than &fn. */ +#define ADDR_EXPR_DENOTES_CALL_P(NODE) \ + (ADDR_EXPR_CHECK(NODE)->base.protected_flag) + /* Get the POINTER_TYPE to the METHOD_TYPE associated with this pointer to member function. TYPE_PTRMEMFUNC_P _must_ be true, before using this macro. */ @@ -6580,6 +6585,24 @@ extern int class_dump_id; extern int module_dump_id; extern int raw_dump_id; +/* Whether the current context is manifestly constant-evaluated. + Used by the constexpr machinery to control folding of + __builtin_is_constant_evaluated. */ + +enum class mce_value +{ + /* Unknown, so treat __builtin_is_constant_evaluated as non-constant. */ + mce_unknown = 0, + /* Fold it to true. */ + mce_true = 1, + /* Fold it to false. Primarily used during cp_fold_function and + cp_fully_fold_init. */ + mce_false = -1, +}; +constexpr mce_value mce_unknown = mce_value::mce_unknown; +constexpr mce_value mce_true = mce_value::mce_true; +constexpr mce_value mce_false = mce_value::mce_false; + /* in call.cc */ extern bool check_dtor_name (tree, tree); int magic_varargs_p (tree); @@ -8354,6 +8377,7 @@ extern tree process_stmt_assume_attribute (tree, tree, location_t); extern bool simple_empty_class_p (tree, tree, tree_code); extern tree fold_builtin_source_location (const_tree); extern tree get_source_location_impl_type (); +extern bool cp_fold_immediate (tree *, mce_value); /* in name-lookup.cc */ extern tree strip_using_decl (tree); @@ -8515,24 +8539,6 @@ struct GTY((for_user)) constexpr_fundef { tree result; }; -/* Whether the current context is manifestly constant-evaluated. - Used by the constexpr machinery to control folding of - __builtin_is_constant_evaluated. */ - -enum class mce_value -{ - /* Unknown, so treat __builtin_is_constant_evaluated as non-constant. */ - mce_unknown = 0, - /* Fold it to true. */ - mce_true = 1, - /* Fold it to false. Primarily used during cp_fold_function and - cp_fully_fold_init. */ - mce_false = -1, -}; -constexpr mce_value mce_unknown = mce_value::mce_unknown; -constexpr mce_value mce_true = mce_value::mce_true; -constexpr mce_value mce_false = mce_value::mce_false; - extern void fini_constexpr (void); extern bool literal_type_p (tree); extern void maybe_save_constexpr_fundef (tree); diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc index 799183dc646..eaf882f8854 100644 --- a/gcc/cp/tree.cc +++ b/gcc/cp/tree.cc @@ -3254,7 +3254,7 @@ bot_manip (tree* tp, int* walk_subtrees, void* data_) variables. */ static tree -bot_replace (tree* t, int* walk_subtrees, void* data_) +bot_replace (tree* t, int */*walk_subtrees*/, void* data_) { bot_data &data = *(bot_data*)data_; splay_tree target_remap = data.target_remap; @@ -3284,27 +3284,6 @@ bot_replace (tree* t, int* walk_subtrees, void* data_) /*check_access=*/false, /*nonnull=*/true, tf_warning_or_error); } - else if (cxx_dialect >= cxx20 - && (TREE_CODE (*t) == CALL_EXPR - || TREE_CODE (*t) == AGGR_INIT_EXPR) - && !in_immediate_context ()) - { - /* Expand immediate invocations. */ - if (tree fndecl = cp_get_callee_fndecl_nofold (*t)) - if (DECL_IMMEDIATE_FUNCTION_P (fndecl)) - { - /* Make in_immediate_context true within the args. */ - in_consteval_if_p_temp_override ito; - in_consteval_if_p = true; - int nargs = call_expr_nargs (*t); - for (int i = 0; i < nargs; ++i) - cp_walk_tree (&get_nth_callarg (*t, i), bot_replace, data_, NULL); - *t = cxx_constant_value (*t); - if (*t == error_mark_node) - return error_mark_node; - *walk_subtrees = 0; - } - } return NULL_TREE; } diff --git a/gcc/testsuite/g++.dg/cpp23/consteval-if2.C b/gcc/testsuite/g++.dg/cpp23/consteval-if2.C index d1845da9e58..b2c5472b7de 100644 --- a/gcc/testsuite/g++.dg/cpp23/consteval-if2.C +++ b/gcc/testsuite/g++.dg/cpp23/consteval-if2.C @@ -58,6 +58,7 @@ baz (int x) return r; } +// This function is not instantiated so NDR. template constexpr int qux (int x) @@ -65,7 +66,7 @@ qux (int x) int r = 0; if not consteval // { dg-warning "'if consteval' only available with" "" { target c++20_only } } { - r += foo (x); // { dg-error "'x' is not a constant expression" } + r += foo (x); // { dg-error "'x' is not a constant expression" "" { xfail *-*-* } } } else { diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C index 910e7a1ac1e..63f4f1d526a 100644 --- a/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C +++ b/gcc/testsuite/g++.dg/cpp2a/consteval-memfn1.C @@ -25,3 +25,10 @@ void VerifyHash(fixed_string s) { fixed_string::size_static(-1); // { dg-message "expansion of" } s(); // { dg-bogus "" } } + +void +do_test () +{ + fixed_string f; + VerifyHash(f); +} diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval11.C b/gcc/testsuite/g++.dg/cpp2a/consteval11.C index 2f68ec0f892..091127eabbf 100644 --- a/gcc/testsuite/g++.dg/cpp2a/consteval11.C +++ b/gcc/testsuite/g++.dg/cpp2a/consteval11.C @@ -5,21 +5,21 @@ consteval int bar (int i) { if (i != 1) throw 1; return 0; } // { dg-error "is n constexpr int a = bar (1); constexpr int b = bar (2); // { dg-message "in 'constexpr' expansion of" } -constexpr int c = 0 ? bar (3) : 1; // { dg-message "in 'constexpr' expansion of" } +constexpr int c = 0 ? bar (3) : 1; const int d = bar (4); // { dg-message "in 'constexpr' expansion of" } -const int e = 0 ? bar (5) : 1; // { dg-message "in 'constexpr' expansion of" } +const int e = 0 ? bar (5) : 1; int f = bar (1); int g = bar (6); // { dg-message "in 'constexpr' expansion of" } -int h = 0 ? bar (7) : 1; // { dg-message "in 'constexpr' expansion of" } +int h = 0 ? bar (7) : 1; void foo () { constexpr int a = bar (1); constexpr int b = bar (2); // { dg-message "in 'constexpr' expansion of" } - constexpr int c = 0 ? bar (3) : 1; // { dg-message "in 'constexpr' expansion of" } + constexpr int c = 0 ? bar (3) : 1; const int d = bar (4); // { dg-message "in 'constexpr' expansion of" } - const int e = 0 ? bar (5) : 1; // { dg-message "in 'constexpr' expansion of" } + const int e = 0 ? bar (5) : 1; int f = bar (1); int g = bar (6); // { dg-message "in 'constexpr' expansion of" } int h = 0 ? bar (7) : 1; // { dg-message "in 'constexpr' expansion of" } @@ -33,13 +33,13 @@ foo () else bar (12); // { dg-message "in 'constexpr' expansion of" } if constexpr (0) - bar (13); // { dg-message "in 'constexpr' expansion of" } + bar (13); else bar (14); // { dg-message "in 'constexpr' expansion of" } if constexpr (1) bar (15); // { dg-message "in 'constexpr' expansion of" } else - bar (16); // { dg-message "in 'constexpr' expansion of" } + bar (16); } consteval int @@ -77,22 +77,25 @@ template void qux () { + // Used to give errors errors here, but not since we moved consteval + // function folding to cp_fold_r which isn't called on uninstantiated + // templates. if (0) - bar (2); // { dg-message "in 'constexpr' expansion of" } + bar (2); else - bar (3); // { dg-message "in 'constexpr' expansion of" } + bar (3); if (1) - bar (4); // { dg-message "in 'constexpr' expansion of" } + bar (4); else - bar (5); // { dg-message "in 'constexpr' expansion of" } + bar (5); if constexpr (0) - bar (6); // { dg-message "in 'constexpr' expansion of" } + bar (6); else - bar (7); // { dg-message "in 'constexpr' expansion of" } + bar (7); if constexpr (1) - bar (8); // { dg-message "in 'constexpr' expansion of" } + bar (8); else - bar (9); // { dg-message "in 'constexpr' expansion of" } + bar (9); if (0) bar ((T) 2); else diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval3.C b/gcc/testsuite/g++.dg/cpp2a/consteval3.C index 627ab142d5a..9efac8c8eae 100644 --- a/gcc/testsuite/g++.dg/cpp2a/consteval3.C +++ b/gcc/testsuite/g++.dg/cpp2a/consteval3.C @@ -18,8 +18,7 @@ consteval int f6 (int x) { return x; } int d = 6; // { dg-message "'int d' is not const" } int e = f6 (d); // { dg-error "the value of 'd' is not usable in a constant expression" } constexpr int f7 (int x) { return f6 (x); } // { dg-error "'x' is not a constant expression" } -constexpr int f = f7 (5); // { dg-error "" } - // { dg-message "in 'constexpr' expansion of" "" { target *-*-* } .-1 } +constexpr int f = f7 (5); using fnptr = int (int); fnptr *g = f6; // { dg-error "taking address of an immediate function 'consteval int f6\\(int\\)'" } int f8 (fnptr *); diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval32.C b/gcc/testsuite/g++.dg/cpp2a/consteval32.C new file mode 100644 index 00000000000..f1de63e41b9 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/consteval32.C @@ -0,0 +1,4 @@ +// { dg-do compile { target c++20 } } + +consteval int foo () { return 42; } +int bar () { return (*(&foo)) (); } // { dg-error "taking address" } diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval33.C b/gcc/testsuite/g++.dg/cpp2a/consteval33.C new file mode 100644 index 00000000000..3d50b00c7a3 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/consteval33.C @@ -0,0 +1,34 @@ +// { dg-do compile { target c++20 } } + +consteval int id (int i) { return i; } +consteval int add (int i, int j) { return i + j; } + +constexpr int +foo (int i = id (42)) +{ + return i + id (id (id (0))); +} + +constexpr int +bar (int i = id (id (id (42)))) +{ + return i; +} + +constexpr int +baz (int i = add (add (id (1), id (2)), id (3))) +{ + return i; +} + +void +g () +{ + foo (); + bar (); + baz (); +} + +static_assert (foo () == 42); +static_assert (bar () == 42); +static_assert (baz () == 6); diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval34.C b/gcc/testsuite/g++.dg/cpp2a/consteval34.C new file mode 100644 index 00000000000..d5e2d1dc5d2 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/consteval34.C @@ -0,0 +1,33 @@ +// { dg-do compile { target c++20 } } + +consteval int bar (int i) { if (i != 1) throw 1; return 0; } // { dg-error "is not a constant expression" } + +constexpr int +foo (bool b) +{ + return b ? bar (3) : 2; // { dg-message "in .constexpr. expansion" } +} + +static_assert (foo (false) == 2); + +__extension__ constexpr int g1 = false ?: bar (2); // { dg-message "in .constexpr. expansion" } +__extension__ constexpr int g2 = false ?: (1 + bar (2)); // { dg-message "in .constexpr. expansion" } +__extension__ constexpr int g3 = true ?: bar (2); +__extension__ constexpr int g4 = true ?: (1 + bar (2)); +constexpr int g5 = bar (2) ? 1 : 2; // { dg-message "in .constexpr. expansion" } +constexpr int g6 = bar (2) - 1 ? 1 : 2; // { dg-message "in .constexpr. expansion" } + +void +g () +{ + __extension__ int a1[bar(3)]; // { dg-message "in .constexpr. expansion" } + int a2[sizeof (bar(3))]; + + int a3 = false ? (1 + bar (8)) : 1; // { dg-message "in .constexpr. expansion" } + a3 += false ? (1 + bar (8)) : 1; // { dg-message "in .constexpr. expansion" } + + __extension__ int a4 = false ?: (1 + bar (8)); // { dg-message "in .constexpr. expansion" } + __extension__ int a5 = true ?: (1 + bar (8)); // { dg-message "in .constexpr. expansion" } + int a6 = bar (2) ? 1 : 2; // { dg-message "in .constexpr. expansion" } + int a7 = bar (2) - 1 ? 1 : 2; // { dg-message "in .constexpr. expansion" } +} diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval35.C b/gcc/testsuite/g++.dg/cpp2a/consteval35.C new file mode 100644 index 00000000000..59d23ac482b --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/consteval35.C @@ -0,0 +1,10 @@ +// { dg-do compile { target c++20 } } + +template +constexpr bool is_not(T t, F f) { + return not f(t); +} + +consteval bool is_even(int i) { return i % 2 == 0; } + +static_assert(is_not(5, is_even)); // ok diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval9.C b/gcc/testsuite/g++.dg/cpp2a/consteval9.C index 489286a12d2..aa75ba37849 100644 --- a/gcc/testsuite/g++.dg/cpp2a/consteval9.C +++ b/gcc/testsuite/g++.dg/cpp2a/consteval9.C @@ -15,10 +15,11 @@ void qux () int a = bar (N); // { dg-message "in 'constexpr' expansion of 'bar\\(2\\)'" } } +// This function is not instantiated so NDR. template void quux () { - int a = bar (5); // { dg-message "in 'constexpr' expansion of 'bar\\(5\\)'" } + int a = bar (5); } void diff --git a/libstdc++-v3/testsuite/20_util/allocator/105975.cc b/libstdc++-v3/testsuite/20_util/allocator/105975.cc index 4866ae6baf9..86e85542342 100644 --- a/libstdc++-v3/testsuite/20_util/allocator/105975.cc +++ b/libstdc++-v3/testsuite/20_util/allocator/105975.cc @@ -13,6 +13,6 @@ consteval bool test_pr105957() a.deallocate(p, n); return true; } -static_assert( test_pr105957() ); +static_assert( test_pr105957() ); // { dg-error "non-constant" } // { dg-error "throw_bad_array_new_length" "" { target *-*-* } 0 }