| // This file is part of GCC. |
| |
| // GCC is free software; you can redistribute it and/or modify it under |
| // the terms of the GNU General Public License as published by the Free |
| // Software Foundation; either version 3, or (at your option) any later |
| // version. |
| |
| // GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| // WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| // for more details. |
| |
| // You should have received a copy of the GNU General Public License |
| // along with GCC; see the file COPYING3. If not see |
| // <http://www.gnu.org/licenses/>. |
| |
| #include "rust-constexpr.h" |
| #include "rust-location.h" |
| #include "rust-diagnostics.h" |
| #include "rust-tree.h" |
| #include "fold-const.h" |
| #include "realmpfr.h" |
| #include "convert.h" |
| #include "print-tree.h" |
| #include "gimplify.h" |
| #include "tree-iterator.h" |
| #include "timevar.h" |
| #include "varasm.h" |
| #include "cgraph.h" |
| #include "tree-inline.h" |
| #include "vec.h" |
| #include "function.h" |
| #include "diagnostic.h" |
| #include "target.h" |
| #include "builtins.h" |
| |
| #define VERIFY_CONSTANT(X) \ |
| do \ |
| { \ |
| if (verify_constant ((X), ctx->quiet, non_constant_p, overflow_p)) \ |
| return t; \ |
| } \ |
| while (0) |
| |
| namespace Rust { |
| namespace Compile { |
| |
| /* Returns true iff FUN is an instantiation of a constexpr function |
| template or a defaulted constexpr function. */ |
| |
| bool |
| is_instantiation_of_constexpr (tree fun) |
| { |
| return DECL_DECLARED_CONSTEXPR_P (fun); |
| } |
| |
| /* Return true if T is a literal type. */ |
| |
| bool |
| literal_type_p (tree t) |
| { |
| if (SCALAR_TYPE_P (t) || VECTOR_TYPE_P (t) || TYPE_REF_P (t) |
| || (VOID_TYPE_P (t))) |
| return true; |
| |
| if (TREE_CODE (t) == ARRAY_TYPE) |
| return literal_type_p (strip_array_types (t)); |
| return false; |
| } |
| |
| static bool |
| verify_constant (tree, bool, bool *, bool *); |
| |
| static HOST_WIDE_INT |
| find_array_ctor_elt (tree ary, tree dindex, bool insert = false); |
| static int |
| array_index_cmp (tree key, tree index); |
| static bool |
| potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, |
| tsubst_flags_t flags, tree *jump_target); |
| bool |
| potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, |
| tsubst_flags_t flags); |
| tree |
| unshare_constructor (tree t MEM_STAT_DECL); |
| void |
| maybe_save_constexpr_fundef (tree fun); |
| |
| static bool |
| returns (tree *jump_target); |
| static bool |
| breaks (tree *jump_target); |
| static bool |
| continues (tree *jump_target); |
| static bool |
| switches (tree *jump_target); |
| |
| struct constexpr_global_ctx |
| { |
| /* Values for any temporaries or local variables within the |
| constant-expression. */ |
| hash_map<tree, tree> values; |
| /* Number of cxx_eval_constant_expression calls (except skipped ones, |
| on simple constants or location wrappers) encountered during current |
| cxx_eval_outermost_constant_expr call. */ |
| HOST_WIDE_INT constexpr_ops_count; |
| /* Heap VAR_DECLs created during the evaluation of the outermost constant |
| expression. */ |
| auto_vec<tree, 16> heap_vars; |
| /* Cleanups that need to be evaluated at the end of CLEANUP_POINT_EXPR. */ |
| vec<tree> *cleanups; |
| /* Number of heap VAR_DECL deallocations. */ |
| unsigned heap_dealloc_count; |
| /* Constructor. */ |
| constexpr_global_ctx () |
| : constexpr_ops_count (0), cleanups (NULL), heap_dealloc_count (0) |
| {} |
| }; |
| |
| /* In constexpr.cc */ |
| /* Representation of entries in the constexpr function definition table. */ |
| |
| struct GTY ((for_user)) rust_constexpr_fundef |
| { |
| tree decl; |
| tree body; |
| tree parms; |
| tree result; |
| }; |
| |
| /* Objects of this type represent calls to constexpr functions |
| along with the bindings of parameters to their arguments, for |
| the purpose of compile time evaluation. */ |
| |
| struct GTY ((for_user)) rust_constexpr_call |
| { |
| /* Description of the constexpr function definition. */ |
| rust_constexpr_fundef *fundef; |
| /* Parameter bindings environment. A TREE_VEC of arguments. */ |
| tree bindings; |
| /* Result of the call. |
| NULL means the call is being evaluated. |
| error_mark_node means that the evaluation was erroneous; |
| otherwise, the actual value of the call. */ |
| tree result; |
| /* The hash of this call; we remember it here to avoid having to |
| recalculate it when expanding the hash table. */ |
| hashval_t hash; |
| /* Whether __builtin_is_constant_evaluated() should evaluate to true. */ |
| bool manifestly_const_eval; |
| }; |
| |
| struct rust_constexpr_call_hasher : ggc_ptr_hash<rust_constexpr_call> |
| { |
| static hashval_t hash (rust_constexpr_call *); |
| static bool equal (rust_constexpr_call *, rust_constexpr_call *); |
| }; |
| |
| enum constexpr_switch_state |
| { |
| /* Used when processing a switch for the first time by cxx_eval_switch_expr |
| and default: label for that switch has not been seen yet. */ |
| css_default_not_seen, |
| /* Used when processing a switch for the first time by cxx_eval_switch_expr |
| and default: label for that switch has been seen already. */ |
| css_default_seen, |
| /* Used when processing a switch for the second time by |
| cxx_eval_switch_expr, where default: label should match. */ |
| css_default_processing |
| }; |
| |
| struct constexpr_ctx |
| { |
| /* The part of the context that needs to be unique to the whole |
| cxx_eval_outermost_constant_expr invocation. */ |
| constexpr_global_ctx *global; |
| /* The innermost call we're evaluating. */ |
| rust_constexpr_call *call; |
| /* SAVE_EXPRs and TARGET_EXPR_SLOT vars of TARGET_EXPRs that we've seen |
| within the current LOOP_EXPR. NULL if we aren't inside a loop. */ |
| vec<tree> *save_exprs; |
| /* The CONSTRUCTOR we're currently building up for an aggregate |
| initializer. */ |
| tree ctor; |
| /* The object we're building the CONSTRUCTOR for. */ |
| tree object; |
| /* If inside SWITCH_EXPR. */ |
| constexpr_switch_state *css_state; |
| /* The aggregate initialization context inside which this one is nested. This |
| is used by lookup_placeholder to resolve PLACEHOLDER_EXPRs. */ |
| const constexpr_ctx *parent; |
| |
| /* Whether we should error on a non-constant expression or fail quietly. |
| This flag needs to be here, but some of the others could move to global |
| if they get larger than a word. */ |
| bool quiet; |
| /* Whether we are strictly conforming to constant expression rules or |
| trying harder to get a constant value. */ |
| bool strict; |
| /* Whether __builtin_is_constant_evaluated () should be true. */ |
| bool manifestly_const_eval; |
| }; |
| |
| struct rust_constexpr_fundef_hasher : ggc_ptr_hash<rust_constexpr_fundef> |
| { |
| static hashval_t hash (const rust_constexpr_fundef *); |
| static bool equal (const rust_constexpr_fundef *, |
| const rust_constexpr_fundef *); |
| }; |
| |
| /* This table holds all constexpr function definitions seen in |
| the current translation unit. */ |
| |
| static GTY (()) |
| hash_table<rust_constexpr_fundef_hasher> *constexpr_fundef_table; |
| |
| /* Utility function used for managing the constexpr function table. |
| Return true if the entries pointed to by P and Q are for the |
| same constexpr function. */ |
| |
| inline bool |
| rust_constexpr_fundef_hasher::equal (const rust_constexpr_fundef *lhs, |
| const rust_constexpr_fundef *rhs) |
| { |
| return lhs->decl == rhs->decl; |
| } |
| |
| /* Utility function used for managing the constexpr function table. |
| Return a hash value for the entry pointed to by Q. */ |
| |
| inline hashval_t |
| rust_constexpr_fundef_hasher::hash (const rust_constexpr_fundef *fundef) |
| { |
| return DECL_UID (fundef->decl); |
| } |
| |
| /* Return a previously saved definition of function FUN. */ |
| |
| rust_constexpr_fundef * |
| retrieve_constexpr_fundef (tree fun) |
| { |
| if (constexpr_fundef_table == NULL) |
| return NULL; |
| |
| rust_constexpr_fundef fundef = {fun, NULL_TREE, NULL_TREE, NULL_TREE}; |
| return constexpr_fundef_table->find (&fundef); |
| } |
| |
| /* This internal flag controls whether we should avoid doing anything during |
| constexpr evaluation that would cause extra DECL_UID generation, such as |
| template instantiation and function body copying. */ |
| |
| static bool uid_sensitive_constexpr_evaluation_value; |
| |
| /* An internal counter that keeps track of the number of times |
| uid_sensitive_constexpr_evaluation_p returned true. */ |
| |
| static unsigned uid_sensitive_constexpr_evaluation_true_counter; |
| |
| /* The accessor for uid_sensitive_constexpr_evaluation_value which also |
| increments the corresponding counter. */ |
| |
| static bool |
| uid_sensitive_constexpr_evaluation_p () |
| { |
| if (uid_sensitive_constexpr_evaluation_value) |
| { |
| ++uid_sensitive_constexpr_evaluation_true_counter; |
| return true; |
| } |
| else |
| return false; |
| } |
| |
| /* RAII sentinel that saves the value of a variable, optionally |
| overrides it right away, and restores its value when the sentinel |
| id destructed. */ |
| |
| template <typename T> class temp_override |
| { |
| T &overridden_variable; |
| T saved_value; |
| |
| public: |
| temp_override (T &var) : overridden_variable (var), saved_value (var) {} |
| temp_override (T &var, T overrider) |
| : overridden_variable (var), saved_value (var) |
| { |
| overridden_variable = overrider; |
| } |
| ~temp_override () { overridden_variable = saved_value; } |
| }; |
| |
| /* An RAII sentinel used to restrict constexpr evaluation so that it |
| doesn't do anything that causes extra DECL_UID generation. */ |
| |
| struct uid_sensitive_constexpr_evaluation_sentinel |
| { |
| temp_override<bool> ovr; |
| uid_sensitive_constexpr_evaluation_sentinel (); |
| }; |
| |
| /* Used to determine whether uid_sensitive_constexpr_evaluation_p was |
| called and returned true, indicating that we've restricted constexpr |
| evaluation in order to avoid UID generation. We use this to control |
| updates to the fold_cache and cv_cache. */ |
| |
| struct uid_sensitive_constexpr_evaluation_checker |
| { |
| const unsigned saved_counter; |
| uid_sensitive_constexpr_evaluation_checker (); |
| bool evaluation_restricted_p () const; |
| }; |
| |
| /* The default constructor for uid_sensitive_constexpr_evaluation_sentinel |
| enables the internal flag for uid_sensitive_constexpr_evaluation_p |
| during the lifetime of the sentinel object. Upon its destruction, the |
| previous value of uid_sensitive_constexpr_evaluation_p is restored. */ |
| |
| uid_sensitive_constexpr_evaluation_sentinel :: |
| uid_sensitive_constexpr_evaluation_sentinel () |
| : ovr (uid_sensitive_constexpr_evaluation_value, true) |
| {} |
| |
| /* The default constructor for uid_sensitive_constexpr_evaluation_checker |
| records the current number of times that uid_sensitive_constexpr_evaluation_p |
| has been called and returned true. */ |
| |
| uid_sensitive_constexpr_evaluation_checker :: |
| uid_sensitive_constexpr_evaluation_checker () |
| : saved_counter (uid_sensitive_constexpr_evaluation_true_counter) |
| {} |
| |
| /* Returns true iff uid_sensitive_constexpr_evaluation_p is true, and |
| some constexpr evaluation was restricted due to u_s_c_e_p being called |
| and returning true during the lifetime of this checker object. */ |
| |
| bool |
| uid_sensitive_constexpr_evaluation_checker::evaluation_restricted_p () const |
| { |
| return (uid_sensitive_constexpr_evaluation_value |
| && saved_counter != uid_sensitive_constexpr_evaluation_true_counter); |
| } |
| |
| /* A table of all constexpr calls that have been evaluated by the |
| compiler in this translation unit. */ |
| |
| static GTY (()) hash_table<rust_constexpr_call_hasher> *constexpr_call_table; |
| |
| /* Compute a hash value for a constexpr call representation. */ |
| |
| inline hashval_t |
| rust_constexpr_call_hasher::hash (rust_constexpr_call *info) |
| { |
| return info->hash; |
| } |
| |
| /* Return true if the objects pointed to by P and Q represent calls |
| to the same constexpr function with the same arguments. |
| Otherwise, return false. */ |
| |
| bool |
| rust_constexpr_call_hasher::equal (rust_constexpr_call *lhs, |
| rust_constexpr_call *rhs) |
| { |
| if (lhs == rhs) |
| return true; |
| if (lhs->hash != rhs->hash) |
| return false; |
| if (lhs->manifestly_const_eval != rhs->manifestly_const_eval) |
| return false; |
| if (!rust_constexpr_fundef_hasher::equal (lhs->fundef, rhs->fundef)) |
| return false; |
| return rs_tree_equal (lhs->bindings, rhs->bindings); |
| } |
| |
| /* Initialize the constexpr call table, if needed. */ |
| |
| static void |
| maybe_initialize_constexpr_call_table (void) |
| { |
| if (constexpr_call_table == NULL) |
| constexpr_call_table |
| = hash_table<rust_constexpr_call_hasher>::create_ggc (101); |
| } |
| |
| /* During constexpr CALL_EXPR evaluation, to avoid issues with sharing when |
| a function happens to get called recursively, we unshare the callee |
| function's body and evaluate this unshared copy instead of evaluating the |
| original body. |
| |
| FUNDEF_COPIES_TABLE is a per-function freelist of these unshared function |
| copies. The underlying data structure of FUNDEF_COPIES_TABLE is a hash_map |
| that's keyed off of the original FUNCTION_DECL and whose value is a |
| TREE_LIST of this function's unused copies awaiting reuse. |
| |
| This is not GC-deletable to avoid GC affecting UID generation. */ |
| |
| static GTY (()) decl_tree_map *fundef_copies_table; |
| |
| /* Reuse a copy or create a new unshared copy of the function FUN. |
| Return this copy. We use a TREE_LIST whose PURPOSE is body, VALUE |
| is parms, TYPE is result. */ |
| |
| static tree |
| get_fundef_copy (rust_constexpr_fundef *fundef) |
| { |
| tree copy; |
| bool existed; |
| tree *slot |
| = &(hash_map_safe_get_or_insert<hm_ggc> (fundef_copies_table, fundef->decl, |
| &existed, 127)); |
| |
| if (!existed) |
| { |
| /* There is no cached function available, or in use. We can use |
| the function directly. That the slot is now created records |
| that this function is now in use. */ |
| copy = build_tree_list (fundef->body, fundef->parms); |
| TREE_TYPE (copy) = fundef->result; |
| } |
| else if (*slot == NULL_TREE) |
| { |
| if (uid_sensitive_constexpr_evaluation_p ()) |
| return NULL_TREE; |
| |
| /* We've already used the function itself, so make a copy. */ |
| copy = build_tree_list (NULL, NULL); |
| tree saved_body = DECL_SAVED_TREE (fundef->decl); |
| tree saved_parms = DECL_ARGUMENTS (fundef->decl); |
| tree saved_result = DECL_RESULT (fundef->decl); |
| tree saved_fn = current_function_decl; |
| DECL_SAVED_TREE (fundef->decl) = fundef->body; |
| DECL_ARGUMENTS (fundef->decl) = fundef->parms; |
| DECL_RESULT (fundef->decl) = fundef->result; |
| current_function_decl = fundef->decl; |
| TREE_PURPOSE (copy) |
| = copy_fn (fundef->decl, TREE_VALUE (copy), TREE_TYPE (copy)); |
| current_function_decl = saved_fn; |
| DECL_RESULT (fundef->decl) = saved_result; |
| DECL_ARGUMENTS (fundef->decl) = saved_parms; |
| DECL_SAVED_TREE (fundef->decl) = saved_body; |
| } |
| else |
| { |
| /* We have a cached function available. */ |
| copy = *slot; |
| *slot = TREE_CHAIN (copy); |
| } |
| |
| return copy; |
| } |
| |
| /* Save the copy COPY of function FUN for later reuse by |
| get_fundef_copy(). By construction, there will always be an entry |
| to find. */ |
| |
| static void |
| save_fundef_copy (tree fun, tree copy) |
| { |
| tree *slot = fundef_copies_table->get (fun); |
| TREE_CHAIN (copy) = *slot; |
| *slot = copy; |
| } |
| |
| static tree |
| constant_value_1 (tree decl, bool strict_p, bool return_aggregate_cst_ok_p, |
| bool unshare_p); |
| tree |
| decl_constant_value (tree decl, bool unshare_p); |
| |
| static void |
| non_const_var_error (location_t loc, tree r); |
| |
| static tree |
| eval_constant_expression (const constexpr_ctx *ctx, tree, bool, bool *, bool *, |
| tree * = NULL); |
| |
| static tree |
| constexpr_fn_retval (const constexpr_ctx *ctx, tree r); |
| |
| static tree |
| eval_store_expression (const constexpr_ctx *ctx, tree r, bool, bool *, bool *); |
| |
| static tree |
| eval_call_expression (const constexpr_ctx *ctx, tree r, bool, bool *, bool *); |
| |
| static tree |
| eval_binary_expression (const constexpr_ctx *ctx, tree r, bool, bool *, bool *); |
| |
| static tree |
| get_function_named_in_call (tree t); |
| |
| static tree |
| eval_statement_list (const constexpr_ctx *ctx, tree t, bool *non_constant_p, |
| bool *overflow_p, tree *jump_target); |
| static tree |
| extract_string_elt (tree string, unsigned chars_per_elt, unsigned index); |
| |
| static tree |
| eval_conditional_expression (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p, |
| tree *jump_target); |
| |
| static tree |
| eval_bit_field_ref (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p); |
| |
| static tree |
| eval_loop_expr (const constexpr_ctx *ctx, tree t, bool *non_constant_p, |
| bool *overflow_p, tree *jump_target); |
| |
| static tree |
| eval_switch_expr (const constexpr_ctx *ctx, tree t, bool *non_constant_p, |
| bool *overflow_p, tree *jump_target); |
| |
| static tree |
| eval_unary_expression (const constexpr_ctx *ctx, tree t, bool /*lval*/, |
| bool *non_constant_p, bool *overflow_p); |
| |
| /* Variables and functions to manage constexpr call expansion context. |
| These do not need to be marked for PCH or GC. */ |
| |
| /* FIXME remember and print actual constant arguments. */ |
| static vec<tree> call_stack; |
| static int call_stack_tick; |
| static int last_cx_error_tick; |
| |
| static int |
| push_cx_call_context (tree call) |
| { |
| ++call_stack_tick; |
| if (!EXPR_HAS_LOCATION (call)) |
| SET_EXPR_LOCATION (call, input_location); |
| call_stack.safe_push (call); |
| int len = call_stack.length (); |
| if (len > max_constexpr_depth) |
| return false; |
| return len; |
| } |
| |
| static void |
| pop_cx_call_context (void) |
| { |
| ++call_stack_tick; |
| call_stack.pop (); |
| } |
| |
| vec<tree> |
| cx_error_context (void) |
| { |
| vec<tree> r = vNULL; |
| if (call_stack_tick != last_cx_error_tick && !call_stack.is_empty ()) |
| r = call_stack; |
| last_cx_error_tick = call_stack_tick; |
| return r; |
| } |
| |
| // this is ported from cxx_eval_outermost_constant_expr |
| tree |
| fold_expr (tree expr) |
| { |
| bool allow_non_constant = false; |
| bool strict = true; |
| bool manifestly_const_eval = false; |
| |
| constexpr_global_ctx global_ctx; |
| constexpr_ctx ctx |
| = {&global_ctx, NULL, |
| NULL, NULL, |
| NULL, NULL, |
| NULL, allow_non_constant, |
| strict, manifestly_const_eval || !allow_non_constant}; |
| |
| auto_vec<tree, 16> cleanups; |
| global_ctx.cleanups = &cleanups; |
| |
| bool non_constant_p = false; |
| bool overflow_p = false; |
| |
| tree folded = eval_constant_expression (&ctx, expr, false, &non_constant_p, |
| &overflow_p); |
| rust_assert (folded != NULL_TREE); |
| |
| // more logic here to possibly port |
| return folded; |
| } |
| |
| static bool |
| same_type_ignoring_tlq_and_bounds_p (tree type1, tree type2) |
| { |
| while (TREE_CODE (type1) == ARRAY_TYPE && TREE_CODE (type2) == ARRAY_TYPE |
| && (!TYPE_DOMAIN (type1) || !TYPE_DOMAIN (type2))) |
| { |
| type1 = TREE_TYPE (type1); |
| type2 = TREE_TYPE (type2); |
| } |
| return same_type_ignoring_top_level_qualifiers_p (type1, type2); |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_union_active_member |
| |
| /* Try to determine the currently active union member for an expression |
| with UNION_TYPE. If it can be determined, return the FIELD_DECL, |
| otherwise return NULL_TREE. */ |
| |
| static tree |
| union_active_member (const constexpr_ctx *ctx, tree t) |
| { |
| constexpr_ctx new_ctx = *ctx; |
| new_ctx.quiet = true; |
| bool non_constant_p = false, overflow_p = false; |
| tree ctor = eval_constant_expression (&new_ctx, t, false, &non_constant_p, |
| &overflow_p); |
| if (TREE_CODE (ctor) == CONSTRUCTOR && CONSTRUCTOR_NELTS (ctor) == 1 |
| && CONSTRUCTOR_ELT (ctor, 0)->index |
| && TREE_CODE (CONSTRUCTOR_ELT (ctor, 0)->index) == FIELD_DECL) |
| return CONSTRUCTOR_ELT (ctor, 0)->index; |
| return NULL_TREE; |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_fold_indirect_ref_1 |
| |
| static tree |
| fold_indirect_ref_1 (const constexpr_ctx *ctx, location_t loc, tree type, |
| tree op, unsigned HOST_WIDE_INT off, bool *empty_base) |
| { |
| tree optype = TREE_TYPE (op); |
| unsigned HOST_WIDE_INT const_nunits; |
| if (off == 0 && similar_type_p (optype, type)) |
| return op; |
| else if (TREE_CODE (optype) == COMPLEX_TYPE |
| && similar_type_p (type, TREE_TYPE (optype))) |
| { |
| /* *(foo *)&complexfoo => __real__ complexfoo */ |
| if (off == 0) |
| return build1_loc (loc, REALPART_EXPR, type, op); |
| /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */ |
| else if (tree_to_uhwi (TYPE_SIZE_UNIT (type)) == off) |
| return build1_loc (loc, IMAGPART_EXPR, type, op); |
| } |
| /* ((foo*)&vectorfoo)[x] => BIT_FIELD_REF<vectorfoo,...> */ |
| else if (VECTOR_TYPE_P (optype) && similar_type_p (type, TREE_TYPE (optype)) |
| && TYPE_VECTOR_SUBPARTS (optype).is_constant (&const_nunits)) |
| { |
| unsigned HOST_WIDE_INT part_width = tree_to_uhwi (TYPE_SIZE_UNIT (type)); |
| unsigned HOST_WIDE_INT max_offset = part_width * const_nunits; |
| if (off < max_offset && off % part_width == 0) |
| { |
| tree index = bitsize_int (off * BITS_PER_UNIT); |
| return build3_loc (loc, BIT_FIELD_REF, type, op, TYPE_SIZE (type), |
| index); |
| } |
| } |
| /* ((foo *)&fooarray)[x] => fooarray[x] */ |
| else if (TREE_CODE (optype) == ARRAY_TYPE |
| && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (optype))) |
| && !integer_zerop (TYPE_SIZE_UNIT (TREE_TYPE (optype)))) |
| { |
| tree type_domain = TYPE_DOMAIN (optype); |
| tree min_val = size_zero_node; |
| if (type_domain && TYPE_MIN_VALUE (type_domain)) |
| min_val = TYPE_MIN_VALUE (type_domain); |
| unsigned HOST_WIDE_INT el_sz |
| = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (optype))); |
| unsigned HOST_WIDE_INT idx = off / el_sz; |
| unsigned HOST_WIDE_INT rem = off % el_sz; |
| if (tree_fits_uhwi_p (min_val)) |
| { |
| tree index = size_int (idx + tree_to_uhwi (min_val)); |
| op = build4_loc (loc, ARRAY_REF, TREE_TYPE (optype), op, index, |
| NULL_TREE, NULL_TREE); |
| return fold_indirect_ref_1 (ctx, loc, type, op, rem, empty_base); |
| } |
| } |
| /* ((foo *)&struct_with_foo_field)[x] => COMPONENT_REF */ |
| else if (TREE_CODE (optype) == RECORD_TYPE |
| || TREE_CODE (optype) == UNION_TYPE) |
| { |
| if (TREE_CODE (optype) == UNION_TYPE) |
| /* For unions prefer the currently active member. */ |
| if (tree field = union_active_member (ctx, op)) |
| { |
| unsigned HOST_WIDE_INT el_sz |
| = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (field))); |
| if (off < el_sz) |
| { |
| tree cop = build3 (COMPONENT_REF, TREE_TYPE (field), op, field, |
| NULL_TREE); |
| if (tree ret = fold_indirect_ref_1 (ctx, loc, type, cop, off, |
| empty_base)) |
| return ret; |
| } |
| } |
| for (tree field = TYPE_FIELDS (optype); field; field = DECL_CHAIN (field)) |
| if (TREE_CODE (field) == FIELD_DECL |
| && TREE_TYPE (field) != error_mark_node |
| && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (field)))) |
| { |
| tree pos = byte_position (field); |
| if (!tree_fits_uhwi_p (pos)) |
| continue; |
| unsigned HOST_WIDE_INT upos = tree_to_uhwi (pos); |
| unsigned HOST_WIDE_INT el_sz |
| = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (field))); |
| if (upos <= off && off < upos + el_sz) |
| { |
| tree cop = build3 (COMPONENT_REF, TREE_TYPE (field), op, field, |
| NULL_TREE); |
| if (tree ret = fold_indirect_ref_1 (ctx, loc, type, cop, |
| off - upos, empty_base)) |
| return ret; |
| } |
| } |
| /* Also handle conversion to an empty base class, which |
| is represented with a NOP_EXPR. */ |
| if (is_empty_class (type) && CLASS_TYPE_P (optype)) |
| { |
| *empty_base = true; |
| return op; |
| } |
| } |
| |
| return NULL_TREE; |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_fold_indirect_ref |
| |
| /* A less strict version of fold_indirect_ref_1, which requires cv-quals to |
| match. We want to be less strict for simple *& folding; if we have a |
| non-const temporary that we access through a const pointer, that should |
| work. We handle this here rather than change fold_indirect_ref_1 |
| because we're dealing with things like ADDR_EXPR of INTEGER_CST which |
| don't really make sense outside of constant expression evaluation. Also |
| we want to allow folding to COMPONENT_REF, which could cause trouble |
| with TBAA in fold_indirect_ref_1. */ |
| |
| static tree |
| rs_fold_indirect_ref (const constexpr_ctx *ctx, location_t loc, tree type, |
| tree op0, bool *empty_base) |
| { |
| tree sub = op0; |
| tree subtype; |
| |
| /* STRIP_NOPS, but stop if REINTERPRET_CAST_P. */ |
| while (CONVERT_EXPR_P (sub) || TREE_CODE (sub) == NON_LVALUE_EXPR |
| || TREE_CODE (sub) == VIEW_CONVERT_EXPR) |
| { |
| if (TREE_CODE (sub) == NOP_EXPR && REINTERPRET_CAST_P (sub)) |
| return NULL_TREE; |
| sub = TREE_OPERAND (sub, 0); |
| } |
| |
| subtype = TREE_TYPE (sub); |
| if (!INDIRECT_TYPE_P (subtype)) |
| return NULL_TREE; |
| |
| /* Canonicalizes the given OBJ/OFF pair by iteratively absorbing |
| the innermost component into the offset until it would make the |
| offset positive, so that cxx_fold_indirect_ref_1 can identify |
| more folding opportunities. */ |
| auto canonicalize_obj_off = [] (tree &obj, tree &off) { |
| while (TREE_CODE (obj) == COMPONENT_REF |
| && (tree_int_cst_sign_bit (off) || integer_zerop (off))) |
| { |
| tree field = TREE_OPERAND (obj, 1); |
| tree pos = byte_position (field); |
| if (integer_zerop (off) && integer_nonzerop (pos)) |
| /* If the offset is already 0, keep going as long as the |
| component is at position 0. */ |
| break; |
| off = int_const_binop (PLUS_EXPR, off, pos); |
| obj = TREE_OPERAND (obj, 0); |
| } |
| }; |
| |
| if (TREE_CODE (sub) == ADDR_EXPR) |
| { |
| tree op = TREE_OPERAND (sub, 0); |
| tree optype = TREE_TYPE (op); |
| |
| /* *&CONST_DECL -> to the value of the const decl. */ |
| if (TREE_CODE (op) == CONST_DECL) |
| return DECL_INITIAL (op); |
| /* *&p => p; make sure to handle *&"str"[cst] here. */ |
| if (similar_type_p (optype, type)) |
| { |
| tree fop = fold_read_from_constant_string (op); |
| if (fop) |
| return fop; |
| else |
| return op; |
| } |
| else |
| { |
| tree off = integer_zero_node; |
| canonicalize_obj_off (op, off); |
| gcc_assert (integer_zerop (off)); |
| return fold_indirect_ref_1 (ctx, loc, type, op, 0, empty_base); |
| } |
| } |
| else if (TREE_CODE (sub) == POINTER_PLUS_EXPR |
| && tree_fits_uhwi_p (TREE_OPERAND (sub, 1))) |
| { |
| tree op00 = TREE_OPERAND (sub, 0); |
| tree off = TREE_OPERAND (sub, 1); |
| |
| STRIP_NOPS (op00); |
| if (TREE_CODE (op00) == ADDR_EXPR) |
| { |
| tree obj = TREE_OPERAND (op00, 0); |
| canonicalize_obj_off (obj, off); |
| return fold_indirect_ref_1 (ctx, loc, type, obj, tree_to_uhwi (off), |
| empty_base); |
| } |
| } |
| /* *(foo *)fooarrptr => (*fooarrptr)[0] */ |
| else if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE |
| && similar_type_p (type, TREE_TYPE (TREE_TYPE (subtype)))) |
| { |
| tree type_domain; |
| tree min_val = size_zero_node; |
| tree newsub |
| = rs_fold_indirect_ref (ctx, loc, TREE_TYPE (subtype), sub, NULL); |
| if (newsub) |
| sub = newsub; |
| else |
| sub = build1_loc (loc, INDIRECT_REF, TREE_TYPE (subtype), sub); |
| type_domain = TYPE_DOMAIN (TREE_TYPE (sub)); |
| if (type_domain && TYPE_MIN_VALUE (type_domain)) |
| min_val = TYPE_MIN_VALUE (type_domain); |
| return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE, |
| NULL_TREE); |
| } |
| |
| return NULL_TREE; |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_indirect_ref |
| |
| static tree |
| rs_eval_indirect_ref (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| tree orig_op0 = TREE_OPERAND (t, 0); |
| bool empty_base = false; |
| |
| /* We can handle a MEM_REF like an INDIRECT_REF, if MEM_REF's second |
| operand is an integer-zero. Otherwise reject the MEM_REF for now. */ |
| |
| if (TREE_CODE (t) == MEM_REF |
| && (!TREE_OPERAND (t, 1) || !integer_zerop (TREE_OPERAND (t, 1)))) |
| { |
| gcc_assert (ctx->quiet); |
| *non_constant_p = true; |
| return t; |
| } |
| |
| /* First try to simplify it directly. */ |
| tree r = rs_fold_indirect_ref (ctx, EXPR_LOCATION (t), TREE_TYPE (t), |
| orig_op0, &empty_base); |
| if (!r) |
| { |
| /* If that didn't work, evaluate the operand first. */ |
| tree op0 |
| = eval_constant_expression (ctx, orig_op0, |
| /*lval*/ false, non_constant_p, overflow_p); |
| /* Don't VERIFY_CONSTANT here. */ |
| if (*non_constant_p) |
| return t; |
| |
| if (!lval && integer_zerop (op0)) |
| { |
| if (!ctx->quiet) |
| error ("dereferencing a null pointer"); |
| *non_constant_p = true; |
| return t; |
| } |
| |
| r = rs_fold_indirect_ref (ctx, EXPR_LOCATION (t), TREE_TYPE (t), op0, |
| &empty_base); |
| if (r == NULL_TREE) |
| { |
| /* We couldn't fold to a constant value. Make sure it's not |
| something we should have been able to fold. */ |
| tree sub = op0; |
| STRIP_NOPS (sub); |
| if (TREE_CODE (sub) == ADDR_EXPR) |
| { |
| gcc_assert ( |
| !similar_type_p (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t))); |
| /* DR 1188 says we don't have to deal with this. */ |
| if (!ctx->quiet) |
| error_at (rs_expr_loc_or_input_loc (t), |
| "accessing value of %qE through a %qT glvalue in a " |
| "constant expression", |
| build_fold_indirect_ref (sub), TREE_TYPE (t)); |
| *non_constant_p = true; |
| return t; |
| } |
| |
| if (lval && op0 != orig_op0) |
| return build1 (INDIRECT_REF, TREE_TYPE (t), op0); |
| if (!lval) |
| VERIFY_CONSTANT (t); |
| return t; |
| } |
| } |
| |
| r = eval_constant_expression (ctx, r, lval, non_constant_p, overflow_p); |
| if (*non_constant_p) |
| return t; |
| |
| /* If we're pulling out the value of an empty base, just return an empty |
| CONSTRUCTOR. */ |
| if (empty_base && !lval) |
| { |
| r = build_constructor (TREE_TYPE (t), NULL); |
| TREE_CONSTANT (r) = true; |
| } |
| |
| return r; |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_logical_expression |
| |
| /* Subroutine of cxx_eval_constant_expression. |
| Evaluate a short-circuited logical expression T in the context |
| of a given constexpr CALL. BAILOUT_VALUE is the value for |
| early return. CONTINUE_VALUE is used here purely for |
| sanity check purposes. */ |
| |
| static tree |
| eval_logical_expression (const constexpr_ctx *ctx, tree t, tree bailout_value, |
| tree continue_value, bool lval, bool *non_constant_p, |
| bool *overflow_p) |
| { |
| tree r; |
| tree lhs = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, |
| non_constant_p, overflow_p); |
| VERIFY_CONSTANT (lhs); |
| if (tree_int_cst_equal (lhs, bailout_value)) |
| return lhs; |
| gcc_assert (tree_int_cst_equal (lhs, continue_value)); |
| r = eval_constant_expression (ctx, TREE_OPERAND (t, 1), lval, non_constant_p, |
| overflow_p); |
| VERIFY_CONSTANT (r); |
| return r; |
| } |
| |
| // forked from gcc/cp/constexp.rcc lookup_placeholder |
| |
| /* Find the object of TYPE under initialization in CTX. */ |
| |
| static tree |
| lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type) |
| { |
| if (!ctx) |
| return NULL_TREE; |
| |
| /* Prefer the outermost matching object, but don't cross |
| CONSTRUCTOR_PLACEHOLDER_BOUNDARY constructors. */ |
| if (ctx->ctor && !CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ctx->ctor)) |
| if (tree outer_ob = lookup_placeholder (ctx->parent, lval, type)) |
| return outer_ob; |
| |
| /* We could use ctx->object unconditionally, but using ctx->ctor when we |
| can is a minor optimization. */ |
| if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type)) |
| return ctx->ctor; |
| |
| if (!ctx->object) |
| return NULL_TREE; |
| |
| /* Since an object cannot have a field of its own type, we can search outward |
| from ctx->object to find the unique containing object of TYPE. */ |
| tree ob = ctx->object; |
| while (ob) |
| { |
| if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (ob), type)) |
| break; |
| if (handled_component_p (ob)) |
| ob = TREE_OPERAND (ob, 0); |
| else |
| ob = NULL_TREE; |
| } |
| |
| return ob; |
| } |
| |
| // forked from gcc/cp/constexp.rcc inline_asm_in_constexpr_error |
| |
| /* Complain about an attempt to evaluate inline assembly. */ |
| |
| static void |
| inline_asm_in_constexpr_error (location_t loc) |
| { |
| auto_diagnostic_group d; |
| error_at (loc, "inline assembly is not a constant expression"); |
| inform (loc, "only unevaluated inline assembly is allowed in a " |
| "%<constexpr%> function in C++20"); |
| } |
| |
| // forked from gcc/cp/constexpr.cc verify_ctor_sanity |
| |
| /* We're about to process an initializer for a class or array TYPE. Make |
| sure that CTX is set up appropriately. */ |
| |
| static void |
| verify_ctor_sanity (const constexpr_ctx *ctx, tree type) |
| { |
| /* We don't bother building a ctor for an empty base subobject. */ |
| if (is_empty_class (type)) |
| return; |
| |
| /* We're in the middle of an initializer that might involve placeholders; |
| our caller should have created a CONSTRUCTOR for us to put the |
| initializer into. We will either return that constructor or T. */ |
| gcc_assert (ctx->ctor); |
| gcc_assert ( |
| same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (ctx->ctor))); |
| /* We used to check that ctx->ctor was empty, but that isn't the case when |
| the object is zero-initialized before calling the constructor. */ |
| if (ctx->object) |
| { |
| tree otype = TREE_TYPE (ctx->object); |
| gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, otype) |
| /* Handle flexible array members. */ |
| || (TREE_CODE (otype) == ARRAY_TYPE |
| && TYPE_DOMAIN (otype) == NULL_TREE |
| && TREE_CODE (type) == ARRAY_TYPE |
| && (same_type_ignoring_top_level_qualifiers_p ( |
| TREE_TYPE (type), TREE_TYPE (otype))))); |
| } |
| gcc_assert (!ctx->object || !DECL_P (ctx->object) |
| || *(ctx->global->values.get (ctx->object)) == ctx->ctor); |
| } |
| |
| // forked from gcc/cp/constexpr.cc array_index_cmp |
| |
| /* Some of the expressions fed to the constexpr mechanism are calls to |
| constructors, which have type void. In that case, return the type being |
| initialized by the constructor. */ |
| |
| static tree |
| initialized_type (tree t) |
| { |
| if (TYPE_P (t)) |
| return t; |
| tree type = TREE_TYPE (t); |
| if (TREE_CODE (t) == CALL_EXPR) |
| { |
| /* A constructor call has void type, so we need to look deeper. */ |
| tree fn = get_function_named_in_call (t); |
| if (fn && TREE_CODE (fn) == FUNCTION_DECL && DECL_CXX_CONSTRUCTOR_P (fn)) |
| type = DECL_CONTEXT (fn); |
| } |
| else if (TREE_CODE (t) == COMPOUND_EXPR) |
| return initialized_type (TREE_OPERAND (t, 1)); |
| |
| return cv_unqualified (type); |
| } |
| |
| // forked from gcc/cp/constexpr.cc init_subob_ctx |
| |
| /* We're about to initialize element INDEX of an array or class from VALUE. |
| Set up NEW_CTX appropriately by adjusting .object to refer to the |
| subobject and creating a new CONSTRUCTOR if the element is itself |
| a class or array. */ |
| |
| static void |
| init_subob_ctx (const constexpr_ctx *ctx, constexpr_ctx &new_ctx, tree index, |
| tree &value) |
| { |
| new_ctx = *ctx; |
| |
| if (index && TREE_CODE (index) != INTEGER_CST |
| && TREE_CODE (index) != FIELD_DECL && TREE_CODE (index) != RANGE_EXPR) |
| /* This won't have an element in the new CONSTRUCTOR. */ |
| return; |
| |
| tree type = initialized_type (value); |
| if (!AGGREGATE_TYPE_P (type) && !VECTOR_TYPE_P (type)) |
| /* A non-aggregate member doesn't get its own CONSTRUCTOR. */ |
| return; |
| |
| /* The sub-aggregate initializer might contain a placeholder; |
| update object to refer to the subobject and ctor to refer to |
| the (newly created) sub-initializer. */ |
| if (ctx->object) |
| { |
| if (index == NULL_TREE || TREE_CODE (index) == RANGE_EXPR) |
| /* There's no well-defined subobject for this index. */ |
| new_ctx.object = NULL_TREE; |
| else |
| { |
| // Faisal: commenting this out as not sure if it's needed and it's |
| // huge new_ctx.object = build_ctor_subob_ref (index, type, |
| // ctx->object); |
| } |
| } |
| tree elt = build_constructor (type, NULL); |
| CONSTRUCTOR_NO_CLEARING (elt) = true; |
| new_ctx.ctor = elt; |
| |
| if (TREE_CODE (value) == TARGET_EXPR) |
| /* Avoid creating another CONSTRUCTOR when we expand the TARGET_EXPR. */ |
| value = TARGET_EXPR_INITIAL (value); |
| } |
| |
| // forked from gcc/cp/constexpr.cc base_field_constructor_elt |
| |
| /* REF is a COMPONENT_REF designating a particular field. V is a vector of |
| CONSTRUCTOR elements to initialize (part of) an object containing that |
| field. Return a pointer to the constructor_elt corresponding to the |
| initialization of the field. */ |
| |
| static constructor_elt * |
| base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref) |
| { |
| tree aggr = TREE_OPERAND (ref, 0); |
| tree field = TREE_OPERAND (ref, 1); |
| HOST_WIDE_INT i; |
| constructor_elt *ce; |
| |
| gcc_assert (TREE_CODE (ref) == COMPONENT_REF); |
| |
| if (TREE_CODE (aggr) == COMPONENT_REF) |
| { |
| constructor_elt *base_ce = base_field_constructor_elt (v, aggr); |
| v = CONSTRUCTOR_ELTS (base_ce->value); |
| } |
| |
| for (i = 0; vec_safe_iterate (v, i, &ce); ++i) |
| if (ce->index == field) |
| return ce; |
| |
| rust_unreachable (); |
| return NULL; |
| } |
| |
| /* Return a pointer to the constructor_elt of CTOR which matches INDEX. If no |
| matching constructor_elt exists, then add one to CTOR. |
| |
| As an optimization, if POS_HINT is non-negative then it is used as a guess |
| for the (integer) index of the matching constructor_elt within CTOR. */ |
| |
| static constructor_elt * |
| get_or_insert_ctor_field (tree ctor, tree index, int pos_hint = -1) |
| { |
| /* Check the hint first. */ |
| if (pos_hint >= 0 && (unsigned) pos_hint < CONSTRUCTOR_NELTS (ctor) |
| && CONSTRUCTOR_ELT (ctor, pos_hint)->index == index) |
| return CONSTRUCTOR_ELT (ctor, pos_hint); |
| |
| tree type = TREE_TYPE (ctor); |
| if (TREE_CODE (type) == VECTOR_TYPE && index == NULL_TREE) |
| { |
| CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (ctor), index, NULL_TREE); |
| return &CONSTRUCTOR_ELTS (ctor)->last (); |
| } |
| else if (TREE_CODE (type) == ARRAY_TYPE || TREE_CODE (type) == VECTOR_TYPE) |
| { |
| if (TREE_CODE (index) == RANGE_EXPR) |
| { |
| /* Support for RANGE_EXPR index lookups is currently limited to |
| accessing an existing element via POS_HINT, or appending a new |
| element to the end of CTOR. ??? Support for other access |
| patterns may also be needed. */ |
| vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ctor); |
| if (vec_safe_length (elts)) |
| { |
| tree lo = TREE_OPERAND (index, 0); |
| gcc_assert (array_index_cmp (elts->last ().index, lo) < 0); |
| } |
| CONSTRUCTOR_APPEND_ELT (elts, index, NULL_TREE); |
| return &elts->last (); |
| } |
| |
| HOST_WIDE_INT i = find_array_ctor_elt (ctor, index, /*insert*/ true); |
| gcc_assert (i >= 0); |
| constructor_elt *cep = CONSTRUCTOR_ELT (ctor, i); |
| gcc_assert (cep->index == NULL_TREE |
| || TREE_CODE (cep->index) != RANGE_EXPR); |
| return cep; |
| } |
| else |
| { |
| gcc_assert ( |
| TREE_CODE (index) == FIELD_DECL |
| && (same_type_ignoring_top_level_qualifiers_p (DECL_CONTEXT (index), |
| TREE_TYPE (ctor)))); |
| |
| /* We must keep the CONSTRUCTOR's ELTS in FIELD order. |
| Usually we meet initializers in that order, but it is |
| possible for base types to be placed not in program |
| order. */ |
| tree fields = TYPE_FIELDS (DECL_CONTEXT (index)); |
| unsigned HOST_WIDE_INT idx = 0; |
| constructor_elt *cep = NULL; |
| |
| /* Check if we're changing the active member of a union. */ |
| if (TREE_CODE (type) == UNION_TYPE && CONSTRUCTOR_NELTS (ctor) |
| && CONSTRUCTOR_ELT (ctor, 0)->index != index) |
| vec_safe_truncate (CONSTRUCTOR_ELTS (ctor), 0); |
| /* If the bit offset of INDEX is larger than that of the last |
| constructor_elt, then we can just immediately append a new |
| constructor_elt to the end of CTOR. */ |
| else if (CONSTRUCTOR_NELTS (ctor) |
| && tree_int_cst_compare ( |
| bit_position (index), |
| bit_position (CONSTRUCTOR_ELTS (ctor)->last ().index)) |
| > 0) |
| { |
| idx = CONSTRUCTOR_NELTS (ctor); |
| goto insert; |
| } |
| |
| /* Otherwise, we need to iterate over CTOR to find or insert INDEX |
| appropriately. */ |
| |
| for (; vec_safe_iterate (CONSTRUCTOR_ELTS (ctor), idx, &cep); |
| idx++, fields = DECL_CHAIN (fields)) |
| { |
| if (index == cep->index) |
| goto found; |
| |
| /* The field we're initializing must be on the field |
| list. Look to see if it is present before the |
| field the current ELT initializes. */ |
| for (; fields != cep->index; fields = DECL_CHAIN (fields)) |
| if (index == fields) |
| goto insert; |
| } |
| /* We fell off the end of the CONSTRUCTOR, so insert a new |
| entry at the end. */ |
| |
| insert : { |
| constructor_elt ce = {index, NULL_TREE}; |
| |
| vec_safe_insert (CONSTRUCTOR_ELTS (ctor), idx, ce); |
| cep = CONSTRUCTOR_ELT (ctor, idx); |
| } |
| found:; |
| |
| return cep; |
| } |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_vector_conditional_expression |
| |
| /* Subroutine of cxx_eval_constant_expression. |
| Attempt to evaluate vector condition expressions. Unlike |
| cxx_eval_conditional_expression, VEC_COND_EXPR acts like a normal |
| ternary arithmetics operation, where all 3 arguments have to be |
| evaluated as constants and then folding computes the result from |
| them. */ |
| |
| static tree |
| eval_vector_conditional_expression (const constexpr_ctx *ctx, tree t, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| tree arg1 |
| = eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
| /*lval*/ false, non_constant_p, overflow_p); |
| VERIFY_CONSTANT (arg1); |
| tree arg2 |
| = eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
| /*lval*/ false, non_constant_p, overflow_p); |
| VERIFY_CONSTANT (arg2); |
| tree arg3 |
| = eval_constant_expression (ctx, TREE_OPERAND (t, 2), |
| /*lval*/ false, non_constant_p, overflow_p); |
| VERIFY_CONSTANT (arg3); |
| location_t loc = EXPR_LOCATION (t); |
| tree type = TREE_TYPE (t); |
| tree r = fold_ternary_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); |
| if (r == NULL_TREE) |
| { |
| if (arg1 == TREE_OPERAND (t, 0) && arg2 == TREE_OPERAND (t, 1) |
| && arg3 == TREE_OPERAND (t, 2)) |
| r = t; |
| else |
| r = build3_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); |
| } |
| VERIFY_CONSTANT (r); |
| return r; |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_bare_aggregate |
| |
| /* Subroutine of cxx_eval_constant_expression. |
| The expression tree T denotes a C-style array or a C-style |
| aggregate. Reduce it to a constant expression. */ |
| |
| static tree |
| eval_bare_aggregate (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); |
| bool changed = false; |
| gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t)); |
| tree type = TREE_TYPE (t); |
| |
| constexpr_ctx new_ctx; |
| if (TYPE_PTRMEMFUNC_P (type) || VECTOR_TYPE_P (type)) |
| { |
| /* We don't really need the ctx->ctor business for a PMF or |
| vector, but it's simpler to use the same code. */ |
| new_ctx = *ctx; |
| new_ctx.ctor = build_constructor (type, NULL); |
| new_ctx.object = NULL_TREE; |
| ctx = &new_ctx; |
| }; |
| verify_ctor_sanity (ctx, type); |
| vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); |
| vec_alloc (*p, vec_safe_length (v)); |
| |
| if (CONSTRUCTOR_PLACEHOLDER_BOUNDARY (t)) |
| CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ctx->ctor) = 1; |
| |
| unsigned i; |
| tree index, value; |
| bool constant_p = true; |
| bool side_effects_p = false; |
| FOR_EACH_CONSTRUCTOR_ELT (v, i, index, value) |
| { |
| tree orig_value = value; |
| /* Like in cxx_eval_store_expression, omit entries for empty fields. */ |
| bool no_slot = TREE_CODE (type) == RECORD_TYPE && is_empty_field (index); |
| if (no_slot) |
| new_ctx = *ctx; |
| else |
| init_subob_ctx (ctx, new_ctx, index, value); |
| int pos_hint = -1; |
| if (new_ctx.ctor != ctx->ctor) |
| { |
| /* If we built a new CONSTRUCTOR, attach it now so that other |
| initializers can refer to it. */ |
| constructor_elt *cep = get_or_insert_ctor_field (ctx->ctor, index); |
| cep->value = new_ctx.ctor; |
| pos_hint = cep - (*p)->begin (); |
| } |
| else if (TREE_CODE (type) == UNION_TYPE) |
| /* Otherwise if we're constructing a non-aggregate union member, set |
| the active union member now so that we can later detect and diagnose |
| if its initializer attempts to activate another member. */ |
| get_or_insert_ctor_field (ctx->ctor, index); |
| tree elt = eval_constant_expression (&new_ctx, value, lval, |
| non_constant_p, overflow_p); |
| /* Don't VERIFY_CONSTANT here. */ |
| if (ctx->quiet && *non_constant_p) |
| break; |
| if (elt != orig_value) |
| changed = true; |
| |
| if (!TREE_CONSTANT (elt)) |
| constant_p = false; |
| if (TREE_SIDE_EFFECTS (elt)) |
| side_effects_p = true; |
| if (index && TREE_CODE (index) == COMPONENT_REF) |
| { |
| /* This is an initialization of a vfield inside a base |
| subaggregate that we already initialized; push this |
| initialization into the previous initialization. */ |
| constructor_elt *inner = base_field_constructor_elt (*p, index); |
| inner->value = elt; |
| changed = true; |
| } |
| else if (index |
| && (TREE_CODE (index) == NOP_EXPR |
| || TREE_CODE (index) == POINTER_PLUS_EXPR)) |
| { |
| /* This is an initializer for an empty base; now that we've |
| checked that it's constant, we can ignore it. */ |
| gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (index)))); |
| changed = true; |
| } |
| else if (no_slot) |
| changed = true; |
| else |
| { |
| if (TREE_CODE (type) == UNION_TYPE && (*p)->last ().index != index) |
| /* The initializer erroneously changed the active union member that |
| we're initializing. */ |
| gcc_assert (*non_constant_p); |
| else |
| { |
| /* The initializer might have mutated the underlying CONSTRUCTOR, |
| so recompute the location of the target constructer_elt. */ |
| constructor_elt *cep |
| = get_or_insert_ctor_field (ctx->ctor, index, pos_hint); |
| cep->value = elt; |
| } |
| |
| /* Adding or replacing an element might change the ctor's flags. */ |
| TREE_CONSTANT (ctx->ctor) = constant_p; |
| TREE_SIDE_EFFECTS (ctx->ctor) = side_effects_p; |
| } |
| } |
| if (*non_constant_p || !changed) |
| return t; |
| t = ctx->ctor; |
| /* We're done building this CONSTRUCTOR, so now we can interpret an |
| element without an explicit initializer as value-initialized. */ |
| CONSTRUCTOR_NO_CLEARING (t) = false; |
| TREE_CONSTANT (t) = constant_p; |
| TREE_SIDE_EFFECTS (t) = side_effects_p; |
| if (VECTOR_TYPE_P (type)) |
| t = fold (t); |
| return t; |
| } |
| |
| /* Subroutine of cxx_eval_constant_expression. |
| Like cxx_eval_unary_expression, except for trinary expressions. */ |
| |
| static tree |
| cxx_eval_trinary_expression (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| int i; |
| tree args[3]; |
| tree val; |
| |
| for (i = 0; i < 3; i++) |
| { |
| args[i] = eval_constant_expression (ctx, TREE_OPERAND (t, i), lval, |
| non_constant_p, overflow_p); |
| VERIFY_CONSTANT (args[i]); |
| } |
| |
| val = fold_ternary_loc (EXPR_LOCATION (t), TREE_CODE (t), TREE_TYPE (t), |
| args[0], args[1], args[2]); |
| if (val == NULL_TREE) |
| return t; |
| VERIFY_CONSTANT (val); |
| return val; |
| } |
| |
| /* Return true if T is a valid constant initializer. If a CONSTRUCTOR |
| initializes all the members, the CONSTRUCTOR_NO_CLEARING flag will be |
| cleared. |
| FIXME speed this up, it's taking 16% of compile time on sieve testcase. */ |
| |
| bool |
| reduced_constant_expression_p (tree t) |
| { |
| if (t == NULL_TREE) |
| return false; |
| |
| switch (TREE_CODE (t)) |
| { |
| case PTRMEM_CST: |
| /* Even if we can't lower this yet, it's constant. */ |
| return true; |
| |
| case CONSTRUCTOR: |
| /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */ |
| tree field; |
| if (CONSTRUCTOR_NO_CLEARING (t)) |
| { |
| if (TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE) |
| /* An initialized vector would have a VECTOR_CST. */ |
| return false; |
| else if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE) |
| { |
| /* There must be a valid constant initializer at every array |
| index. */ |
| tree min = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (t))); |
| tree max = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (t))); |
| tree cursor = min; |
| for (auto &e : CONSTRUCTOR_ELTS (t)) |
| { |
| if (!reduced_constant_expression_p (e.value)) |
| return false; |
| if (array_index_cmp (cursor, e.index) != 0) |
| return false; |
| if (TREE_CODE (e.index) == RANGE_EXPR) |
| cursor = TREE_OPERAND (e.index, 1); |
| cursor = int_const_binop (PLUS_EXPR, cursor, size_one_node); |
| } |
| if (find_array_ctor_elt (t, max) == -1) |
| return false; |
| goto ok; |
| } |
| else if (TREE_CODE (TREE_TYPE (t)) == UNION_TYPE) |
| { |
| if (CONSTRUCTOR_NELTS (t) == 0) |
| /* An initialized union has a constructor element. */ |
| return false; |
| /* And it only initializes one member. */ |
| field = NULL_TREE; |
| } |
| else |
| field = next_initializable_field (TYPE_FIELDS (TREE_TYPE (t))); |
| } |
| else |
| field = NULL_TREE; |
| for (auto &e : CONSTRUCTOR_ELTS (t)) |
| { |
| /* If VAL is null, we're in the middle of initializing this |
| element. */ |
| if (!reduced_constant_expression_p (e.value)) |
| return false; |
| /* Empty class field may or may not have an initializer. */ |
| for (; field && e.index != field; |
| field = next_initializable_field (DECL_CHAIN (field))) |
| if (!is_really_empty_class (TREE_TYPE (field), |
| /*ignore_vptr*/ false)) |
| return false; |
| if (field) |
| field = next_initializable_field (DECL_CHAIN (field)); |
| } |
| /* There could be a non-empty field at the end. */ |
| for (; field; field = next_initializable_field (DECL_CHAIN (field))) |
| if (!is_really_empty_class (TREE_TYPE (field), /*ignore_vptr*/ false)) |
| return false; |
| ok: |
| if (CONSTRUCTOR_NO_CLEARING (t)) |
| /* All the fields are initialized. */ |
| CONSTRUCTOR_NO_CLEARING (t) = false; |
| return true; |
| |
| default: |
| /* FIXME are we calling this too much? */ |
| return initializer_constant_valid_p (t, TREE_TYPE (t)) != NULL_TREE; |
| } |
| } |
| |
| /* TEMP is the constant value of a temporary object of type TYPE. Adjust |
| the type of the value to match. */ |
| |
| static tree |
| adjust_temp_type (tree type, tree temp) |
| { |
| if (same_type_p (TREE_TYPE (temp), type)) |
| return temp; |
| |
| gcc_assert (scalarish_type_p (type)); |
| /* Now we know we're dealing with a scalar, and a prvalue of non-class |
| type is cv-unqualified. */ |
| return fold_convert (cv_unqualified (type), temp); |
| } |
| |
| // forked from gcc/cp/constexpr.cc free_constructor |
| |
| /* If T is a CONSTRUCTOR, ggc_free T and any sub-CONSTRUCTORs. */ |
| |
| static void |
| free_constructor (tree t) |
| { |
| if (!t || TREE_CODE (t) != CONSTRUCTOR) |
| return; |
| releasing_vec ctors; |
| vec_safe_push (ctors, t); |
| while (!ctors->is_empty ()) |
| { |
| tree c = ctors->pop (); |
| if (vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (c)) |
| { |
| constructor_elt *ce; |
| for (HOST_WIDE_INT i = 0; vec_safe_iterate (elts, i, &ce); ++i) |
| if (TREE_CODE (ce->value) == CONSTRUCTOR) |
| vec_safe_push (ctors, ce->value); |
| ggc_free (elts); |
| } |
| ggc_free (c); |
| } |
| } |
| |
| static tree |
| eval_and_check_array_index (const constexpr_ctx *ctx, tree t, |
| bool allow_one_past, bool *non_constant_p, |
| bool *overflow_p); |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_array_reference |
| |
| /* Subroutine of cxx_eval_constant_expression. |
| Attempt to reduce a reference to an array slot. */ |
| |
| static tree |
| eval_array_reference (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| tree oldary = TREE_OPERAND (t, 0); |
| tree ary |
| = eval_constant_expression (ctx, oldary, lval, non_constant_p, overflow_p); |
| if (*non_constant_p) |
| return t; |
| if (!lval && TREE_CODE (ary) == VIEW_CONVERT_EXPR |
| && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0))) |
| && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0)))) |
| ary = TREE_OPERAND (ary, 0); |
| |
| tree oldidx = TREE_OPERAND (t, 1); |
| tree index |
| = eval_and_check_array_index (ctx, t, lval, non_constant_p, overflow_p); |
| if (*non_constant_p) |
| return t; |
| |
| if (lval && ary == oldary && index == oldidx) |
| return t; |
| else if (lval) |
| return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL); |
| |
| unsigned len = 0, elem_nchars = 1; |
| tree elem_type = TREE_TYPE (TREE_TYPE (ary)); |
| if (TREE_CODE (ary) == CONSTRUCTOR) |
| len = CONSTRUCTOR_NELTS (ary); |
| else if (TREE_CODE (ary) == STRING_CST) |
| { |
| elem_nchars |
| = (TYPE_PRECISION (elem_type) / TYPE_PRECISION (char_type_node)); |
| len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars; |
| } |
| else if (TREE_CODE (ary) == VECTOR_CST) |
| /* We don't create variable-length VECTOR_CSTs. */ |
| len = VECTOR_CST_NELTS (ary).to_constant (); |
| else |
| { |
| /* We can't do anything with other tree codes, so use |
| VERIFY_CONSTANT to complain and fail. */ |
| VERIFY_CONSTANT (ary); |
| rust_unreachable (); |
| } |
| |
| bool found; |
| HOST_WIDE_INT i = 0; |
| if (TREE_CODE (ary) == CONSTRUCTOR) |
| { |
| HOST_WIDE_INT ix = find_array_ctor_elt (ary, index); |
| found = (ix >= 0); |
| if (found) |
| i = ix; |
| } |
| else |
| { |
| i = tree_to_shwi (index); |
| found = (i < len); |
| } |
| |
| if (found) |
| { |
| tree r; |
| if (TREE_CODE (ary) == CONSTRUCTOR) |
| r = (*CONSTRUCTOR_ELTS (ary))[i].value; |
| else if (TREE_CODE (ary) == VECTOR_CST) |
| r = VECTOR_CST_ELT (ary, i); |
| else |
| r = extract_string_elt (ary, elem_nchars, i); |
| |
| if (r) |
| /* Don't VERIFY_CONSTANT here. */ |
| return r; |
| |
| /* Otherwise the element doesn't have a value yet. */ |
| } |
| |
| /* Not found. */ |
| |
| if (TREE_CODE (ary) == CONSTRUCTOR && CONSTRUCTOR_NO_CLEARING (ary)) |
| { |
| /* 'ary' is part of the aggregate initializer we're currently |
| building; if there's no initializer for this element yet, |
| that's an error. */ |
| if (!ctx->quiet) |
| error ("accessing uninitialized array element"); |
| *non_constant_p = true; |
| return t; |
| } |
| |
| /* If it's within the array bounds but doesn't have an explicit |
| initializer, it's initialized from {}. But use build_value_init |
| directly for non-aggregates to avoid creating a garbage CONSTRUCTOR. */ |
| tree val = NULL_TREE; |
| sorry ("array size expression is not supported yet"); |
| |
| constexpr_ctx new_ctx; |
| if (is_really_empty_class (elem_type, /*ignore_vptr*/ false)) |
| return build_constructor (elem_type, NULL); |
| // else if (CP_AGGREGATE_TYPE_P (elem_type)) |
| // { |
| // tree empty_ctor = build_constructor (init_list_type_node, NULL); |
| // //val = digest_init (elem_type, empty_ctor, tf_warning_or_error); |
| // } |
| // else |
| // val = build_value_init (elem_type, tf_warning_or_error); |
| |
| if (!SCALAR_TYPE_P (elem_type)) |
| { |
| new_ctx = *ctx; |
| if (ctx->object) |
| /* If there was no object, don't add one: it could confuse us |
| into thinking we're modifying a const object. */ |
| new_ctx.object = t; |
| new_ctx.ctor = build_constructor (elem_type, NULL); |
| ctx = &new_ctx; |
| } |
| t = eval_constant_expression (ctx, val, lval, non_constant_p, overflow_p); |
| if (!SCALAR_TYPE_P (elem_type) && t != ctx->ctor) |
| free_constructor (ctx->ctor); |
| return t; |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_component_reference |
| |
| /* Subroutine of cxx_eval_constant_expression. |
| Attempt to reduce a field access of a value of class type. */ |
| |
| static tree |
| eval_component_reference (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| unsigned HOST_WIDE_INT i; |
| tree field; |
| tree value; |
| tree part = TREE_OPERAND (t, 1); |
| tree orig_whole = TREE_OPERAND (t, 0); |
| tree whole = eval_constant_expression (ctx, orig_whole, lval, non_constant_p, |
| overflow_p); |
| if (INDIRECT_REF_P (whole) && integer_zerop (TREE_OPERAND (whole, 0))) |
| { |
| if (!ctx->quiet) |
| error ("dereferencing a null pointer in %qE", orig_whole); |
| *non_constant_p = true; |
| return t; |
| } |
| |
| if (whole == orig_whole) |
| return t; |
| if (lval) |
| return fold_build3 (COMPONENT_REF, TREE_TYPE (t), whole, part, NULL_TREE); |
| /* Don't VERIFY_CONSTANT here; we only want to check that we got a |
| CONSTRUCTOR. */ |
| if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR) |
| { |
| if (!ctx->quiet) |
| error ("%qE is not a constant expression", orig_whole); |
| *non_constant_p = true; |
| } |
| if (DECL_MUTABLE_P (part)) |
| { |
| if (!ctx->quiet) |
| error ("mutable %qD is not usable in a constant expression", part); |
| *non_constant_p = true; |
| } |
| if (*non_constant_p) |
| return t; |
| bool pmf = TYPE_PTRMEMFUNC_P (TREE_TYPE (whole)); |
| FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) |
| { |
| /* Use name match for PMF fields, as a variant will have a |
| different FIELD_DECL with a different type. */ |
| if (pmf ? DECL_NAME (field) == DECL_NAME (part) : field == part) |
| { |
| if (value) |
| { |
| STRIP_ANY_LOCATION_WRAPPER (value); |
| return value; |
| } |
| else |
| /* We're in the middle of initializing it. */ |
| break; |
| } |
| } |
| if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE |
| && CONSTRUCTOR_NELTS (whole) > 0) |
| { |
| /* DR 1188 says we don't have to deal with this. */ |
| if (!ctx->quiet) |
| { |
| constructor_elt *cep = CONSTRUCTOR_ELT (whole, 0); |
| if (cep->value == NULL_TREE) |
| error ("accessing uninitialized member %qD", part); |
| else |
| error ("accessing %qD member instead of initialized %qD member in " |
| "constant expression", |
| part, cep->index); |
| } |
| *non_constant_p = true; |
| return t; |
| } |
| |
| /* We only create a CONSTRUCTOR for a subobject when we modify it, so empty |
| classes never get represented; throw together a value now. */ |
| if (is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/ false)) |
| return build_constructor (TREE_TYPE (t), NULL); |
| |
| gcc_assert (DECL_CONTEXT (part) == TYPE_MAIN_VARIANT (TREE_TYPE (whole))); |
| |
| if (CONSTRUCTOR_NO_CLEARING (whole)) |
| { |
| /* 'whole' is part of the aggregate initializer we're currently |
| building; if there's no initializer for this member yet, that's an |
| error. */ |
| if (!ctx->quiet) |
| error ("accessing uninitialized member %qD", part); |
| *non_constant_p = true; |
| return t; |
| } |
| |
| value = NULL_TREE; |
| sorry ("constant folding not supported for this tree code"); |
| /* If there's no explicit init for this field, it's value-initialized. */ |
| // Faisal: commenting this out as not sure if we need this but we need to come |
| // back to handle this to assign suitable value to value before sending it in |
| // eval_constant_expression below |
| // value = build_value_init (TREE_TYPE (t), tf_warning_or_error); |
| return eval_constant_expression (ctx, value, lval, non_constant_p, |
| overflow_p); |
| } |
| |
| /* Subroutine of cxx_eval_statement_list. Determine whether the statement |
| STMT matches *jump_target. If we're looking for a case label and we see |
| the default label, note it in ctx->css_state. */ |
| |
| static bool |
| label_matches (const constexpr_ctx *ctx, tree *jump_target, tree stmt) |
| { |
| switch (TREE_CODE (*jump_target)) |
| { |
| case LABEL_DECL: |
| if (TREE_CODE (stmt) == LABEL_EXPR |
| && LABEL_EXPR_LABEL (stmt) == *jump_target) |
| return true; |
| break; |
| |
| case INTEGER_CST: |
| if (TREE_CODE (stmt) == CASE_LABEL_EXPR) |
| { |
| gcc_assert (ctx->css_state != NULL); |
| if (!CASE_LOW (stmt)) |
| { |
| /* default: should appear just once in a SWITCH_EXPR |
| body (excluding nested SWITCH_EXPR). */ |
| gcc_assert (*ctx->css_state != css_default_seen); |
| /* When evaluating SWITCH_EXPR body for the second time, |
| return true for the default: label. */ |
| if (*ctx->css_state == css_default_processing) |
| return true; |
| *ctx->css_state = css_default_seen; |
| } |
| else if (CASE_HIGH (stmt)) |
| { |
| if (tree_int_cst_le (CASE_LOW (stmt), *jump_target) |
| && tree_int_cst_le (*jump_target, CASE_HIGH (stmt))) |
| return true; |
| } |
| else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt))) |
| return true; |
| } |
| break; |
| |
| case BREAK_STMT: |
| case CONTINUE_STMT: |
| /* These two are handled directly in cxx_eval_loop_expr by testing |
| breaks (jump_target) or continues (jump_target). */ |
| break; |
| |
| default: |
| rust_unreachable (); |
| } |
| return false; |
| } |
| |
| static tree |
| eval_constant_expression (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p, |
| tree *jump_target /* = NULL */) |
| { |
| if (jump_target && *jump_target) |
| { |
| /* If we are jumping, ignore all statements/expressions except those |
| that could have LABEL_EXPR or CASE_LABEL_EXPR in their bodies. */ |
| switch (TREE_CODE (t)) |
| { |
| case BIND_EXPR: |
| case STATEMENT_LIST: |
| case LOOP_EXPR: |
| case COND_EXPR: |
| case IF_STMT: |
| case DO_STMT: |
| case WHILE_STMT: |
| case FOR_STMT: |
| break; |
| case LABEL_EXPR: |
| case CASE_LABEL_EXPR: |
| if (label_matches (ctx, jump_target, t)) |
| /* Found it. */ |
| *jump_target = NULL_TREE; |
| return NULL_TREE; |
| default: |
| return NULL_TREE; |
| } |
| } |
| if (error_operand_p (t)) |
| { |
| *non_constant_p = true; |
| return t; |
| } |
| |
| location_t loc = EXPR_LOCATION (t); |
| |
| if (CONSTANT_CLASS_P (t)) |
| { |
| if (TREE_OVERFLOW (t)) |
| { |
| error_at (loc, "overflow in constant expression"); |
| return t; |
| } |
| |
| return t; |
| } |
| |
| // Avoid excessively long constexpr evaluations |
| if (++ctx->global->constexpr_ops_count >= constexpr_ops_limit) |
| { |
| rust_error_at ( |
| loc, |
| "%<constexpr%> evaluation operation count exceeds limit of " |
| "%wd (use %<-fconstexpr-ops-limit=%> to increase the limit)", |
| constexpr_ops_limit); |
| |
| return t; |
| } |
| |
| constexpr_ctx new_ctx; |
| tree r = t; |
| tree_code tcode = TREE_CODE (t); |
| switch (tcode) |
| { |
| case VAR_DECL: |
| if (DECL_HAS_VALUE_EXPR_P (t)) |
| { |
| r = DECL_VALUE_EXPR (t); |
| return eval_constant_expression (ctx, r, lval, non_constant_p, |
| overflow_p); |
| } |
| /* fall through */ |
| case CONST_DECL: { |
| /* We used to not check lval for CONST_DECL, but darwin.cc uses |
| CONST_DECL for aggregate constants. */ |
| if (lval) |
| return t; |
| else if (t == ctx->object) |
| return ctx->ctor; |
| if (VAR_P (t)) |
| if (tree *p = ctx->global->values.get (t)) |
| if (*p != NULL_TREE) |
| { |
| r = *p; |
| break; |
| } |
| r = decl_constant_value (t, /*unshare_p=*/false); |
| if (TREE_CODE (r) == TARGET_EXPR |
| && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR) |
| r = TARGET_EXPR_INITIAL (r); |
| if (DECL_P (r)) |
| { |
| non_const_var_error (loc, r); |
| return r; |
| } |
| } |
| break; |
| |
| case PARM_DECL: |
| if (lval && !TYPE_REF_P (TREE_TYPE (t))) |
| /* glvalue use. */; |
| else if (tree *p = ctx->global->values.get (r)) |
| r = *p; |
| else if (lval) |
| /* Defer in case this is only used for its type. */; |
| else if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
| && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/ false)) |
| { |
| /* If the class is empty, we aren't actually loading anything. */ |
| r = build_constructor (TREE_TYPE (t), NULL); |
| TREE_CONSTANT (r) = true; |
| } |
| else |
| { |
| if (!ctx->quiet) |
| error ("%qE is not a constant expression", t); |
| *non_constant_p = true; |
| } |
| break; |
| |
| case POINTER_PLUS_EXPR: |
| case POINTER_DIFF_EXPR: |
| case PLUS_EXPR: |
| case MINUS_EXPR: |
| case MULT_EXPR: |
| case TRUNC_DIV_EXPR: |
| case CEIL_DIV_EXPR: |
| case FLOOR_DIV_EXPR: |
| case ROUND_DIV_EXPR: |
| case TRUNC_MOD_EXPR: |
| case CEIL_MOD_EXPR: |
| case ROUND_MOD_EXPR: |
| case RDIV_EXPR: |
| case EXACT_DIV_EXPR: |
| case MIN_EXPR: |
| case MAX_EXPR: |
| case LSHIFT_EXPR: |
| case RSHIFT_EXPR: |
| case LROTATE_EXPR: |
| case RROTATE_EXPR: |
| case BIT_IOR_EXPR: |
| case BIT_XOR_EXPR: |
| case BIT_AND_EXPR: |
| case TRUTH_XOR_EXPR: |
| case LT_EXPR: |
| case LE_EXPR: |
| case GT_EXPR: |
| case GE_EXPR: |
| case EQ_EXPR: |
| case NE_EXPR: |
| case SPACESHIP_EXPR: |
| case UNORDERED_EXPR: |
| case ORDERED_EXPR: |
| case UNLT_EXPR: |
| case UNLE_EXPR: |
| case UNGT_EXPR: |
| case UNGE_EXPR: |
| case UNEQ_EXPR: |
| case LTGT_EXPR: |
| case RANGE_EXPR: |
| case COMPLEX_EXPR: |
| r = eval_binary_expression (ctx, t, lval, non_constant_p, overflow_p); |
| break; |
| |
| /* fold can introduce non-IF versions of these; still treat them as |
| short-circuiting. */ |
| case TRUTH_AND_EXPR: |
| case TRUTH_ANDIF_EXPR: |
| r = eval_logical_expression (ctx, t, boolean_false_node, |
| boolean_true_node, lval, non_constant_p, |
| overflow_p); |
| break; |
| |
| case TRUTH_OR_EXPR: |
| case TRUTH_ORIF_EXPR: |
| r = eval_logical_expression (ctx, t, boolean_true_node, |
| boolean_false_node, lval, non_constant_p, |
| overflow_p); |
| break; |
| |
| case TARGET_EXPR: { |
| tree type = TREE_TYPE (t); |
| |
| if (!literal_type_p (type)) |
| { |
| if (!ctx->quiet) |
| { |
| auto_diagnostic_group d; |
| error ("temporary of non-literal type %qT in a " |
| "constant expression", |
| type); |
| explain_non_literal_class (type); |
| } |
| *non_constant_p = true; |
| break; |
| } |
| gcc_checking_assert (!TARGET_EXPR_DIRECT_INIT_P (t)); |
| /* Avoid evaluating a TARGET_EXPR more than once. */ |
| tree slot = TARGET_EXPR_SLOT (t); |
| if (tree *p = ctx->global->values.get (slot)) |
| { |
| if (lval) |
| return slot; |
| r = *p; |
| break; |
| } |
| if ((AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type))) |
| { |
| /* We're being expanded without an explicit target, so start |
| initializing a new object; expansion with an explicit target |
| strips the TARGET_EXPR before we get here. */ |
| new_ctx = *ctx; |
| /* Link CTX to NEW_CTX so that lookup_placeholder can resolve |
| any PLACEHOLDER_EXPR within the initializer that refers to the |
| former object under construction. */ |
| new_ctx.parent = ctx; |
| new_ctx.ctor = build_constructor (type, NULL); |
| CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; |
| new_ctx.object = slot; |
| ctx->global->values.put (new_ctx.object, new_ctx.ctor); |
| ctx = &new_ctx; |
| } |
| /* Pass false for 'lval' because this indicates |
| initialization of a temporary. */ |
| r = eval_constant_expression (ctx, TREE_OPERAND (t, 1), false, |
| non_constant_p, overflow_p); |
| if (*non_constant_p) |
| break; |
| /* Adjust the type of the result to the type of the temporary. */ |
| r = adjust_temp_type (type, r); |
| if (TARGET_EXPR_CLEANUP (t) && !CLEANUP_EH_ONLY (t)) |
| ctx->global->cleanups->safe_push (TARGET_EXPR_CLEANUP (t)); |
| r = unshare_constructor (r); |
| ctx->global->values.put (slot, r); |
| if (ctx->save_exprs) |
| ctx->save_exprs->safe_push (slot); |
| if (lval) |
| return slot; |
| } |
| break; |
| |
| case CALL_EXPR: |
| r = eval_call_expression (ctx, t, lval, non_constant_p, overflow_p); |
| break; |
| |
| case RETURN_EXPR: |
| if (TREE_OPERAND (t, 0) != NULL_TREE) |
| r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, |
| non_constant_p, overflow_p); |
| /* FALLTHRU */ |
| case BREAK_STMT: |
| case CONTINUE_STMT: |
| if (jump_target) |
| *jump_target = t; |
| else |
| { |
| /* Can happen with ({ return true; }) && false; passed to |
| maybe_constant_value. There is nothing to jump over in this |
| case, and the bug will be diagnosed later. */ |
| gcc_assert (ctx->quiet); |
| *non_constant_p = true; |
| } |
| break; |
| |
| case DECL_EXPR: { |
| r = DECL_EXPR_DECL (t); |
| |
| if (AGGREGATE_TYPE_P (TREE_TYPE (r)) || VECTOR_TYPE_P (TREE_TYPE (r))) |
| { |
| new_ctx = *ctx; |
| new_ctx.object = r; |
| new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL); |
| CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; |
| ctx->global->values.put (r, new_ctx.ctor); |
| ctx = &new_ctx; |
| } |
| |
| if (tree init = DECL_INITIAL (r)) |
| { |
| init = eval_constant_expression (ctx, init, false, non_constant_p, |
| overflow_p); |
| /* Don't share a CONSTRUCTOR that might be changed. */ |
| init = unshare_constructor (init); |
| /* Remember that a constant object's constructor has already |
| run. */ |
| if (CLASS_TYPE_P (TREE_TYPE (r)) && RS_TYPE_CONST_P (TREE_TYPE (r))) |
| TREE_READONLY (init) = true; |
| ctx->global->values.put (r, init); |
| } |
| else if (ctx == &new_ctx) |
| /* We gave it a CONSTRUCTOR above. */; |
| else |
| ctx->global->values.put (r, NULL_TREE); |
| } |
| break; |
| |
| /* These differ from cxx_eval_unary_expression in that this doesn't |
| check for a constant operand or result; an address can be |
| constant without its operand being, and vice versa. */ |
| case MEM_REF: |
| case INDIRECT_REF: |
| r = rs_eval_indirect_ref (ctx, t, lval, non_constant_p, overflow_p); |
| break; |
| |
| case VEC_PERM_EXPR: |
| r = cxx_eval_trinary_expression (ctx, t, lval, non_constant_p, |
| overflow_p); |
| break; |
| |
| case PAREN_EXPR: |
| gcc_assert (!REF_PARENTHESIZED_P (t)); |
| /* A PAREN_EXPR resulting from __builtin_assoc_barrier has no effect in |
| constant expressions since it's unaffected by -fassociative-math. */ |
| r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, |
| non_constant_p, overflow_p); |
| break; |
| |
| case MODIFY_EXPR: |
| r = eval_store_expression (ctx, t, false, non_constant_p, overflow_p); |
| break; |
| |
| case STATEMENT_LIST: |
| new_ctx = *ctx; |
| new_ctx.ctor = new_ctx.object = NULL_TREE; |
| return eval_statement_list (&new_ctx, t, non_constant_p, overflow_p, |
| jump_target); |
| |
| case BIND_EXPR: |
| return eval_constant_expression (ctx, BIND_EXPR_BODY (t), lval, |
| non_constant_p, overflow_p, jump_target); |
| |
| case OBJ_TYPE_REF: |
| /* Virtual function lookup. We don't need to do anything fancy. */ |
| return eval_constant_expression (ctx, OBJ_TYPE_REF_EXPR (t), lval, |
| non_constant_p, overflow_p); |
| |
| case EXIT_EXPR: { |
| tree cond = TREE_OPERAND (t, 0); |
| cond = eval_constant_expression (ctx, cond, /*lval*/ false, |
| non_constant_p, overflow_p); |
| VERIFY_CONSTANT (cond); |
| if (integer_nonzerop (cond)) |
| *jump_target = t; |
| } |
| break; |
| |
| case RESULT_DECL: |
| if (lval) |
| return t; |
| /* We ask for an rvalue for the RESULT_DECL when indirecting |
| through an invisible reference, or in named return value |
| optimization. */ |
| if (tree *p = ctx->global->values.get (t)) |
| return *p; |
| else |
| { |
| if (!ctx->quiet) |
| error ("%qE is not a constant expression", t); |
| *non_constant_p = true; |
| } |
| break; |
| |
| case SAVE_EXPR: |
| /* Avoid evaluating a SAVE_EXPR more than once. */ |
| if (tree *p = ctx->global->values.get (t)) |
| r = *p; |
| else |
| { |
| r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), false, |
| non_constant_p, overflow_p); |
| if (*non_constant_p) |
| break; |
| ctx->global->values.put (t, r); |
| if (ctx->save_exprs) |
| ctx->save_exprs->safe_push (t); |
| } |
| break; |
| |
| case ADDR_EXPR: { |
| tree oldop = TREE_OPERAND (t, 0); |
| tree op = eval_constant_expression (ctx, oldop, |
| /*lval*/ true, non_constant_p, |
| overflow_p); |
| /* Don't VERIFY_CONSTANT here. */ |
| if (*non_constant_p) |
| return t; |
| /* This function does more aggressive folding than fold itself. */ |
| r = build_fold_addr_expr_with_type (op, TREE_TYPE (t)); |
| if (TREE_CODE (r) == ADDR_EXPR && TREE_OPERAND (r, 0) == oldop) |
| { |
| ggc_free (r); |
| return t; |
| } |
| break; |
| } |
| |
| case COMPOUND_EXPR: { |
| /* check_return_expr sometimes wraps a TARGET_EXPR in a |
| COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR |
| introduced by build_call_a. */ |
| tree op0 = TREE_OPERAND (t, 0); |
| tree op1 = TREE_OPERAND (t, 1); |
| STRIP_NOPS (op1); |
| if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) |
| || TREE_CODE (op1) == EMPTY_CLASS_EXPR) |
| r = eval_constant_expression (ctx, op0, lval, non_constant_p, |
| overflow_p, jump_target); |
| else |
| { |
| /* Check that the LHS is constant and then discard it. */ |
| eval_constant_expression (ctx, op0, true, non_constant_p, |
| overflow_p, jump_target); |
| if (*non_constant_p) |
| return t; |
| op1 = TREE_OPERAND (t, 1); |
| r = eval_constant_expression (ctx, op1, lval, non_constant_p, |
| overflow_p, jump_target); |
| } |
| } |
| break; |
| |
| case REALPART_EXPR: |
| case IMAGPART_EXPR: |
| if (lval) |
| { |
| r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, |
| non_constant_p, overflow_p); |
| if (r == error_mark_node) |
| ; |
| else if (r == TREE_OPERAND (t, 0)) |
| r = t; |
| else |
| r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), r); |
| break; |
| } |
| /* FALLTHRU */ |
| case CONJ_EXPR: |
| case FIX_TRUNC_EXPR: |
| case FLOAT_EXPR: |
| case NEGATE_EXPR: |
| case ABS_EXPR: |
| case ABSU_EXPR: |
| case BIT_NOT_EXPR: |
| case TRUTH_NOT_EXPR: |
| case FIXED_CONVERT_EXPR: |
| r = eval_unary_expression (ctx, t, lval, non_constant_p, overflow_p); |
| break; |
| |
| case LOOP_EXPR: |
| case WHILE_STMT: |
| case FOR_STMT: |
| eval_loop_expr (ctx, t, non_constant_p, overflow_p, jump_target); |
| break; |
| |
| case SWITCH_EXPR: |
| case SWITCH_STMT: |
| eval_switch_expr (ctx, t, non_constant_p, overflow_p, jump_target); |
| break; |
| |
| case ARRAY_REF: |
| r = eval_array_reference (ctx, t, lval, non_constant_p, overflow_p); |
| break; |
| |
| case COMPONENT_REF: |
| if (is_overloaded_fn (t)) |
| { |
| /* We can only get here in checking mode via |
| build_non_dependent_expr, because any expression that |
| calls or takes the address of the function will have |
| pulled a FUNCTION_DECL out of the COMPONENT_REF. */ |
| gcc_checking_assert (ctx->quiet || errorcount); |
| *non_constant_p = true; |
| return t; |
| } |
| r = eval_component_reference (ctx, t, lval, non_constant_p, overflow_p); |
| break; |
| |
| case BIT_FIELD_REF: |
| r = eval_bit_field_ref (ctx, t, lval, non_constant_p, overflow_p); |
| break; |
| |
| case COND_EXPR: |
| case IF_STMT: // comes from cp-tree.def |
| if (jump_target && *jump_target) |
| { |
| tree orig_jump = *jump_target; |
| tree arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 1)) |
| ? TREE_OPERAND (t, 1) |
| : void_node); |
| /* When jumping to a label, the label might be either in the |
| then or else blocks, so process then block first in skipping |
| mode first, and if we are still in the skipping mode at its end, |
| process the else block too. */ |
| r = eval_constant_expression (ctx, arg, lval, non_constant_p, |
| overflow_p, jump_target); |
| /* It's possible that we found the label in the then block. But |
| it could have been followed by another jumping statement, e.g. |
| say we're looking for case 1: |
| if (cond) |
| { |
| // skipped statements |
| case 1:; // clears up *jump_target |
| return 1; // and sets it to a RETURN_EXPR |
| } |
| else { ... } |
| in which case we need not go looking to the else block. |
| (goto is not allowed in a constexpr function.) */ |
| if (*jump_target == orig_jump) |
| { |
| arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 2)) |
| ? TREE_OPERAND (t, 2) |
| : void_node); |
| r = eval_constant_expression (ctx, arg, lval, non_constant_p, |
| overflow_p, jump_target); |
| } |
| break; |
| } |
| r = eval_conditional_expression (ctx, t, lval, non_constant_p, overflow_p, |
| jump_target); |
| break; |
| |
| case VEC_COND_EXPR: |
| r = eval_vector_conditional_expression (ctx, t, non_constant_p, |
| overflow_p); |
| break; |
| |
| case TRY_CATCH_EXPR: |
| if (TREE_OPERAND (t, 0) == NULL_TREE) |
| { |
| r = void_node; |
| break; |
| } |
| r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, |
| non_constant_p, overflow_p, jump_target); |
| break; |
| |
| case CLEANUP_POINT_EXPR: { |
| auto_vec<tree, 2> cleanups; |
| vec<tree> *prev_cleanups = ctx->global->cleanups; |
| ctx->global->cleanups = &cleanups; |
| r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, |
| non_constant_p, overflow_p, jump_target); |
| ctx->global->cleanups = prev_cleanups; |
| unsigned int i; |
| tree cleanup; |
| /* Evaluate the cleanups. */ |
| FOR_EACH_VEC_ELT_REVERSE (cleanups, i, cleanup) |
| eval_constant_expression (ctx, cleanup, false, non_constant_p, |
| overflow_p); |
| } |
| break; |
| |
| case TRY_FINALLY_EXPR: |
| r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, |
| non_constant_p, overflow_p, jump_target); |
| if (!*non_constant_p) |
| /* Also evaluate the cleanup. */ |
| eval_constant_expression (ctx, TREE_OPERAND (t, 1), true, |
| non_constant_p, overflow_p); |
| break; |
| |
| case CONSTRUCTOR: |
| if (TREE_CONSTANT (t) && reduced_constant_expression_p (t)) |
| { |
| /* Don't re-process a constant CONSTRUCTOR, but do fold it to |
| VECTOR_CST if applicable. */ |
| verify_constructor_flags (t); |
| if (TREE_CONSTANT (t)) |
| return fold (t); |
| } |
| r = eval_bare_aggregate (ctx, t, lval, non_constant_p, overflow_p); |
| break; |
| |
| /* FALLTHROUGH. */ |
| case NOP_EXPR: |
| case CONVERT_EXPR: |
| case VIEW_CONVERT_EXPR: { |
| tree oldop = TREE_OPERAND (t, 0); |
| |
| tree op = eval_constant_expression (ctx, oldop, lval, non_constant_p, |
| overflow_p); |
| if (*non_constant_p) |
| return t; |
| tree type = TREE_TYPE (t); |
| |
| if (VOID_TYPE_P (type)) |
| return void_node; |
| |
| if (TREE_CODE (t) == CONVERT_EXPR && ARITHMETIC_TYPE_P (type) |
| && INDIRECT_TYPE_P (TREE_TYPE (op)) && ctx->manifestly_const_eval) |
| { |
| if (!ctx->quiet) |
| error_at (loc, |
| "conversion from pointer type %qT to arithmetic type " |
| "%qT in a constant expression", |
| TREE_TYPE (op), type); |
| *non_constant_p = true; |
| return t; |
| } |
| |
| if (TYPE_PTROB_P (type) && TYPE_PTR_P (TREE_TYPE (op)) |
| && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (op)))) |
| { |
| /* Likewise, don't error when casting from void* when OP is |
| &heap uninit and similar. */ |
| tree sop = tree_strip_nop_conversions (op); |
| if (TREE_CODE (sop) == ADDR_EXPR && VAR_P (TREE_OPERAND (sop, 0)) |
| && DECL_ARTIFICIAL (TREE_OPERAND (sop, 0))) |
| /* OK */; |
| else |
| { |
| if (!ctx->quiet) |
| error_at (loc, "cast from %qT is not allowed", |
| TREE_TYPE (op)); |
| *non_constant_p = true; |
| return t; |
| } |
| } |
| |
| if (INDIRECT_TYPE_P (type) && TREE_CODE (op) == INTEGER_CST) |
| { |
| if (integer_zerop (op)) |
| { |
| if (TYPE_REF_P (type)) |
| { |
| if (!ctx->quiet) |
| error_at (loc, "dereferencing a null pointer"); |
| *non_constant_p = true; |
| return t; |
| } |
| } |
| else |
| { |
| /* This detects for example: |
| reinterpret_cast<void*>(sizeof 0) |
| */ |
| if (!ctx->quiet) |
| error_at (loc, |
| "%<reinterpret_cast<%T>(%E)%> is not " |
| "a constant expression", |
| type, op); |
| *non_constant_p = true; |
| return t; |
| } |
| } |
| |
| if (INDIRECT_TYPE_P (type) && TREE_CODE (op) == NOP_EXPR |
| && TREE_TYPE (op) == ptr_type_node |
| && TREE_CODE (TREE_OPERAND (op, 0)) == ADDR_EXPR |
| && VAR_P (TREE_OPERAND (TREE_OPERAND (op, 0), 0)) |
| && (DECL_NAME (TREE_OPERAND (TREE_OPERAND (op, 0), 0)) |
| == heap_uninit_identifier |
| || DECL_NAME (TREE_OPERAND (TREE_OPERAND (op, 0), 0)) |
| == heap_vec_uninit_identifier)) |
| { |
| tree var = TREE_OPERAND (TREE_OPERAND (op, 0), 0); |
| tree var_size = TYPE_SIZE_UNIT (TREE_TYPE (var)); |
| tree elt_type = TREE_TYPE (type); |
| tree cookie_size = NULL_TREE; |
| if (TREE_CODE (elt_type) == RECORD_TYPE |
| && TYPE_NAME (elt_type) == heap_identifier) |
| { |
| tree fld1 = TYPE_FIELDS (elt_type); |
| tree fld2 = DECL_CHAIN (fld1); |
| elt_type = TREE_TYPE (TREE_TYPE (fld2)); |
| cookie_size = TYPE_SIZE_UNIT (TREE_TYPE (fld1)); |
| } |
| DECL_NAME (var) = (DECL_NAME (var) == heap_uninit_identifier |
| ? heap_identifier |
| : heap_vec_identifier); |
| TREE_TYPE (var) |
| = build_new_constexpr_heap_type (elt_type, cookie_size, var_size); |
| TREE_TYPE (TREE_OPERAND (op, 0)) |
| = build_pointer_type (TREE_TYPE (var)); |
| } |
| |
| if (op == oldop) |
| /* We didn't fold at the top so we could check for ptr-int |
| conversion. */ |
| return fold (t); |
| |
| tree sop; |
| |
| /* Handle an array's bounds having been deduced after we built |
| the wrapping expression. */ |
| if (same_type_ignoring_tlq_and_bounds_p (type, TREE_TYPE (op))) |
| r = op; |
| else if (sop = tree_strip_nop_conversions (op), |
| sop != op |
| && (same_type_ignoring_tlq_and_bounds_p (type, |
| TREE_TYPE (sop)))) |
| r = sop; |
| else |
| r = fold_build1 (tcode, type, op); |
| |
| /* Conversion of an out-of-range value has implementation-defined |
| behavior; the language considers it different from arithmetic |
| overflow, which is undefined. */ |
| if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op)) |
| TREE_OVERFLOW (r) = false; |
| } |
| break; |
| |
| case PLACEHOLDER_EXPR: |
| /* Use of the value or address of the current object. */ |
| if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t))) |
| { |
| if (TREE_CODE (ctor) == CONSTRUCTOR) |
| return ctor; |
| else |
| return eval_constant_expression (ctx, ctor, lval, non_constant_p, |
| overflow_p); |
| } |
| /* A placeholder without a referent. We can get here when |
| checking whether NSDMIs are noexcept, or in massage_init_elt; |
| just say it's non-constant for now. */ |
| gcc_assert (ctx->quiet); |
| *non_constant_p = true; |
| break; |
| |
| case ANNOTATE_EXPR: |
| r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, |
| non_constant_p, overflow_p, jump_target); |
| break; |
| |
| case ASM_EXPR: |
| if (!ctx->quiet) |
| inline_asm_in_constexpr_error (loc); |
| *non_constant_p = true; |
| return t; |
| |
| default: |
| break; |
| } |
| |
| return r; |
| } |
| |
| /* Complain about a const object OBJ being modified in a constant expression. |
| EXPR is the MODIFY_EXPR expression performing the modification. */ |
| |
| static void |
| modifying_const_object_error (tree expr, tree obj) |
| { |
| location_t loc = EXPR_LOCATION (expr); |
| auto_diagnostic_group d; |
| error_at (loc, |
| "modifying a const object %qE is not allowed in " |
| "a constant expression", |
| TREE_OPERAND (expr, 0)); |
| inform (location_of (obj), "originally declared %<const%> here"); |
| } |
| |
| /* Return true iff DECL is an empty field, either for an empty base or a |
| [[no_unique_address]] data member. */ |
| |
| bool |
| is_empty_field (tree decl) |
| { |
| if (!decl || TREE_CODE (decl) != FIELD_DECL) |
| return false; |
| |
| bool r = is_empty_class (TREE_TYPE (decl)); |
| |
| /* Empty fields should have size zero. */ |
| gcc_checking_assert (!r || integer_zerop (DECL_SIZE (decl))); |
| |
| return r; |
| } |
| |
| static tree |
| eval_store_expression (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| constexpr_ctx new_ctx = *ctx; |
| |
| tree init = TREE_OPERAND (t, 1); |
| if (TREE_CLOBBER_P (init)) |
| /* Just ignore clobbers. */ |
| return void_node; |
| |
| /* First we figure out where we're storing to. */ |
| tree target = TREE_OPERAND (t, 0); |
| |
| tree type = TREE_TYPE (target); |
| bool preeval = SCALAR_TYPE_P (type) || TREE_CODE (t) == MODIFY_EXPR; |
| if (preeval) |
| { |
| /* Evaluate the value to be stored without knowing what object it will be |
| stored in, so that any side-effects happen first. */ |
| if (!SCALAR_TYPE_P (type)) |
| new_ctx.ctor = new_ctx.object = NULL_TREE; |
| init = eval_constant_expression (&new_ctx, init, false, non_constant_p, |
| overflow_p); |
| if (*non_constant_p) |
| return t; |
| } |
| |
| bool evaluated = false; |
| if (lval) |
| { |
| /* If we want to return a reference to the target, we need to evaluate it |
| as a whole; otherwise, only evaluate the innermost piece to avoid |
| building up unnecessary *_REFs. */ |
| target = eval_constant_expression (ctx, target, true, non_constant_p, |
| overflow_p); |
| evaluated = true; |
| if (*non_constant_p) |
| return t; |
| } |
| |
| /* Find the underlying variable. */ |
| releasing_vec refs; |
| tree object = NULL_TREE; |
| /* If we're modifying a const object, save it. */ |
| tree const_object_being_modified = NULL_TREE; |
| // bool mutable_p = false; |
| for (tree probe = target; object == NULL_TREE;) |
| { |
| switch (TREE_CODE (probe)) |
| { |
| case BIT_FIELD_REF: |
| case COMPONENT_REF: |
| case ARRAY_REF: { |
| tree ob = TREE_OPERAND (probe, 0); |
| tree elt = TREE_OPERAND (probe, 1); |
| if (TREE_CODE (elt) == FIELD_DECL /*&& DECL_MUTABLE_P (elt)*/) |
| { |
| // mutable_p = true; |
| } |
| if (TREE_CODE (probe) == ARRAY_REF) |
| { |
| // TODO |
| rust_unreachable (); |
| // elt = eval_and_check_array_index (ctx, probe, false, |
| // non_constant_p, overflow_p); |
| if (*non_constant_p) |
| return t; |
| } |
| /* We don't check modifying_const_object_p for ARRAY_REFs. Given |
| "int a[10]", an ARRAY_REF "a[2]" can be "const int", even though |
| the array isn't const. Instead, check "a" in the next iteration; |
| that will detect modifying "const int a[10]". */ |
| // else if (evaluated |
| // && modifying_const_object_p (TREE_CODE (t), probe, |
| // mutable_p) |
| // && const_object_being_modified == NULL_TREE) |
| // const_object_being_modified = probe; |
| vec_safe_push (refs, elt); |
| vec_safe_push (refs, TREE_TYPE (probe)); |
| probe = ob; |
| } |
| break; |
| |
| default: |
| if (evaluated) |
| object = probe; |
| else |
| { |
| probe = eval_constant_expression (ctx, probe, true, |
| non_constant_p, overflow_p); |
| evaluated = true; |
| if (*non_constant_p) |
| return t; |
| } |
| break; |
| } |
| } |
| |
| // if (modifying_const_object_p (TREE_CODE (t), object, mutable_p) |
| // && const_object_being_modified == NULL_TREE) |
| // const_object_being_modified = object; |
| |
| /* And then find/build up our initializer for the path to the subobject |
| we're initializing. */ |
| tree *valp; |
| if (DECL_P (object)) |
| valp = ctx->global->values.get (object); |
| else |
| valp = NULL; |
| if (!valp) |
| { |
| /* A constant-expression cannot modify objects from outside the |
| constant-expression. */ |
| if (!ctx->quiet) |
| error ("modification of %qE is not a constant expression", object); |
| *non_constant_p = true; |
| return t; |
| } |
| type = TREE_TYPE (object); |
| bool no_zero_init = true; |
| |
| releasing_vec ctors, indexes; |
| auto_vec<int> index_pos_hints; |
| bool activated_union_member_p = false; |
| while (!refs->is_empty ()) |
| { |
| if (*valp == NULL_TREE) |
| { |
| *valp = build_constructor (type, NULL); |
| CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
| } |
| else if (TREE_CODE (*valp) == STRING_CST) |
| { |
| /* An array was initialized with a string constant, and now |
| we're writing into one of its elements. Explode the |
| single initialization into a set of element |
| initializations. */ |
| gcc_assert (TREE_CODE (type) == ARRAY_TYPE); |
| |
| tree string = *valp; |
| tree elt_type = TREE_TYPE (type); |
| unsigned chars_per_elt |
| = (TYPE_PRECISION (elt_type) / TYPE_PRECISION (char_type_node)); |
| unsigned num_elts = TREE_STRING_LENGTH (string) / chars_per_elt; |
| tree ary_ctor = build_constructor (type, NULL); |
| |
| vec_safe_reserve (CONSTRUCTOR_ELTS (ary_ctor), num_elts); |
| for (unsigned ix = 0; ix != num_elts; ix++) |
| { |
| constructor_elt elt |
| = {build_int_cst (size_type_node, ix), |
| extract_string_elt (string, chars_per_elt, ix)}; |
| CONSTRUCTOR_ELTS (ary_ctor)->quick_push (elt); |
| } |
| |
| *valp = ary_ctor; |
| } |
| |
| /* If the value of object is already zero-initialized, any new ctors for |
| subobjects will also be zero-initialized. */ |
| no_zero_init = CONSTRUCTOR_NO_CLEARING (*valp); |
| |
| enum tree_code code = TREE_CODE (type); |
| type = refs->pop (); |
| tree index = refs->pop (); |
| |
| if (code == RECORD_TYPE && is_empty_field (index)) |
| /* Don't build a sub-CONSTRUCTOR for an empty base or field, as they |
| have no data and might have an offset lower than previously declared |
| fields, which confuses the middle-end. The code below will notice |
| that we don't have a CONSTRUCTOR for our inner target and just |
| return init. */ |
| break; |
| |
| if (code == UNION_TYPE && CONSTRUCTOR_NELTS (*valp) |
| && CONSTRUCTOR_ELT (*valp, 0)->index != index) |
| { |
| if (TREE_CODE (t) == MODIFY_EXPR && CONSTRUCTOR_NO_CLEARING (*valp)) |
| { |
| /* Diagnose changing the active union member while the union |
| is in the process of being initialized. */ |
| if (!ctx->quiet) |
| error_at (EXPR_LOCATION (t), |
| "change of the active member of a union " |
| "from %qD to %qD during initialization", |
| CONSTRUCTOR_ELT (*valp, 0)->index, index); |
| *non_constant_p = true; |
| } |
| no_zero_init = true; |
| } |
| |
| vec_safe_push (ctors, *valp); |
| vec_safe_push (indexes, index); |
| |
| constructor_elt *cep = get_or_insert_ctor_field (*valp, index); |
| index_pos_hints.safe_push (cep - CONSTRUCTOR_ELTS (*valp)->begin ()); |
| |
| if (code == UNION_TYPE) |
| activated_union_member_p = true; |
| |
| valp = &cep->value; |
| } |
| |
| /* Detect modifying a constant object in constexpr evaluation. |
| We have found a const object that is being modified. Figure out |
| if we need to issue an error. Consider |
| |
| struct A { |
| int n; |
| constexpr A() : n(1) { n = 2; } // #1 |
| }; |
| struct B { |
| const A a; |
| constexpr B() { a.n = 3; } // #2 |
| }; |
| constexpr B b{}; |
| |
| #1 is OK, since we're modifying an object under construction, but |
| #2 is wrong, since "a" is const and has been fully constructed. |
| To track it, we use the TREE_READONLY bit in the object's CONSTRUCTOR |
| which means that the object is read-only. For the example above, the |
| *ctors stack at the point of #2 will look like: |
| |
| ctors[0] = {.a={.n=2}} TREE_READONLY = 0 |
| ctors[1] = {.n=2} TREE_READONLY = 1 |
| |
| and we're modifying "b.a", so we search the stack and see if the |
| constructor for "b.a" has already run. */ |
| if (const_object_being_modified) |
| { |
| bool fail = false; |
| tree const_objtype |
| = strip_array_types (TREE_TYPE (const_object_being_modified)); |
| if (!CLASS_TYPE_P (const_objtype)) |
| fail = true; |
| else |
| { |
| /* [class.ctor]p5 "A constructor can be invoked for a const, |
| volatile, or const volatile object. const and volatile |
| semantics are not applied on an object under construction. |
| They come into effect when the constructor for the most |
| derived object ends." */ |
| for (tree elt : *ctors) |
| if (same_type_ignoring_top_level_qualifiers_p ( |
| TREE_TYPE (const_object_being_modified), TREE_TYPE (elt))) |
| { |
| fail = TREE_READONLY (elt); |
| break; |
| } |
| } |
| if (fail) |
| { |
| if (!ctx->quiet) |
| modifying_const_object_error (t, const_object_being_modified); |
| *non_constant_p = true; |
| return t; |
| } |
| } |
| |
| if (!preeval) |
| { |
| /* We're handling an INIT_EXPR of class type, so the value of the |
| initializer can depend on the object it's initializing. */ |
| |
| /* Create a new CONSTRUCTOR in case evaluation of the initializer |
| wants to modify it. */ |
| if (*valp == NULL_TREE) |
| { |
| *valp = build_constructor (type, NULL); |
| CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
| } |
| new_ctx.ctor = *valp; |
| new_ctx.object = target; |
| /* Avoid temporary materialization when initializing from a TARGET_EXPR. |
| We don't need to mess with AGGR_EXPR_SLOT/VEC_INIT_EXPR_SLOT because |
| expansion of those trees uses ctx instead. */ |
| if (TREE_CODE (init) == TARGET_EXPR) |
| if (tree tinit = TARGET_EXPR_INITIAL (init)) |
| init = tinit; |
| init = eval_constant_expression (&new_ctx, init, false, non_constant_p, |
| overflow_p); |
| /* The hash table might have moved since the get earlier, and the |
| initializer might have mutated the underlying CONSTRUCTORs, so we must |
| recompute VALP. */ |
| valp = ctx->global->values.get (object); |
| for (unsigned i = 0; i < vec_safe_length (indexes); i++) |
| { |
| constructor_elt *cep |
| = get_or_insert_ctor_field (*valp, indexes[i], index_pos_hints[i]); |
| valp = &cep->value; |
| } |
| } |
| |
| /* Don't share a CONSTRUCTOR that might be changed later. */ |
| init = unshare_constructor (init); |
| |
| if (*valp && TREE_CODE (*valp) == CONSTRUCTOR |
| && TREE_CODE (init) == CONSTRUCTOR) |
| { |
| /* An outer ctx->ctor might be pointing to *valp, so replace |
| its contents. */ |
| if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (init), |
| TREE_TYPE (*valp))) |
| { |
| /* For initialization of an empty base, the original target will be |
| *(base*)this, evaluation of which resolves to the object |
| argument, which has the derived type rather than the base type. In |
| this situation, just evaluate the initializer and return, since |
| there's no actual data to store. */ |
| gcc_assert (is_empty_class (TREE_TYPE (init))); |
| return lval ? target : init; |
| } |
| CONSTRUCTOR_ELTS (*valp) = CONSTRUCTOR_ELTS (init); |
| TREE_CONSTANT (*valp) = TREE_CONSTANT (init); |
| TREE_SIDE_EFFECTS (*valp) = TREE_SIDE_EFFECTS (init); |
| CONSTRUCTOR_NO_CLEARING (*valp) = CONSTRUCTOR_NO_CLEARING (init); |
| } |
| // else if (TREE_CODE (init) == CONSTRUCTOR |
| // && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (init), |
| // type)) |
| // { |
| // /* See above on initialization of empty bases. */ |
| // // gcc_assert (is_empty_class (TREE_TYPE (init)) && !lval); |
| // return init; |
| // } |
| else |
| *valp = init; |
| |
| /* After initialization, 'const' semantics apply to the value of the |
| object. Make a note of this fact by marking the CONSTRUCTOR |
| TREE_READONLY. */ |
| if (TREE_CODE (t) == INIT_EXPR && TREE_CODE (*valp) == CONSTRUCTOR |
| && TYPE_READONLY (type)) |
| { |
| // this vs self? can rust's self be anything other than self or &self in |
| // constexpr mode? if (INDIRECT_REF_P (target) |
| // && (is_this_parameter ( |
| // tree_strip_nop_conversions (TREE_OPERAND (target, 0))))) |
| /* We've just initialized '*this' (perhaps via the target |
| constructor of a delegating constructor). Leave it up to the |
| caller that set 'this' to set TREE_READONLY appropriately. */ |
| // gcc_checking_assert ( |
| // same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (target), |
| // type)); |
| // else |
| // TREE_READONLY (*valp) = true; |
| } |
| |
| /* Update TREE_CONSTANT and TREE_SIDE_EFFECTS on enclosing |
| CONSTRUCTORs, if any. */ |
| bool c = TREE_CONSTANT (init); |
| bool s = TREE_SIDE_EFFECTS (init); |
| if (!c || s || activated_union_member_p) |
| for (tree elt : *ctors) |
| { |
| if (!c) |
| TREE_CONSTANT (elt) = false; |
| if (s) |
| TREE_SIDE_EFFECTS (elt) = true; |
| /* Clear CONSTRUCTOR_NO_CLEARING since we've activated a member of |
| this union. */ |
| if (TREE_CODE (TREE_TYPE (elt)) == UNION_TYPE) |
| CONSTRUCTOR_NO_CLEARING (elt) = false; |
| } |
| |
| if (*non_constant_p) |
| return t; |
| else if (lval) |
| return target; |
| else |
| return init; |
| } |
| |
| /* Subroutine of cxx_eval_constant_expression. |
| Like cxx_eval_unary_expression, except for binary expressions. */ |
| static tree |
| eval_binary_expression (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| tree orig_lhs = TREE_OPERAND (t, 0); |
| tree orig_rhs = TREE_OPERAND (t, 1); |
| tree lhs, rhs; |
| |
| lhs = eval_constant_expression (ctx, orig_lhs, lval, non_constant_p, |
| overflow_p); |
| rhs = eval_constant_expression (ctx, orig_rhs, lval, non_constant_p, |
| overflow_p); |
| |
| location_t loc = EXPR_LOCATION (t); |
| enum tree_code code = TREE_CODE (t); |
| tree type = TREE_TYPE (t); |
| |
| return fold_binary_loc (loc, code, type, lhs, rhs); |
| } |
| |
| /* Helper function of cxx_bind_parameters_in_call. Return non-NULL |
| if *TP is address of a static variable (or part of it) currently being |
| constructed or of a heap artificial variable. */ |
| |
| static tree |
| addr_of_non_const_var (tree *tp, int *walk_subtrees, void *data) |
| { |
| if (TREE_CODE (*tp) == ADDR_EXPR) |
| if (tree var = get_base_address (TREE_OPERAND (*tp, 0))) |
| if (VAR_P (var) && TREE_STATIC (var)) |
| { |
| if (DECL_NAME (var) == heap_uninit_identifier |
| || DECL_NAME (var) == heap_identifier |
| || DECL_NAME (var) == heap_vec_uninit_identifier |
| || DECL_NAME (var) == heap_vec_identifier) |
| return var; |
| |
| constexpr_global_ctx *global = (constexpr_global_ctx *) data; |
| if (global->values.get (var)) |
| return var; |
| } |
| if (TYPE_P (*tp)) |
| *walk_subtrees = false; |
| return NULL_TREE; |
| } |
| |
| /* Subroutine of cxx_eval_call_expression. |
| We are processing a call expression (either CALL_EXPR or |
| AGGR_INIT_EXPR) in the context of CTX. Evaluate |
| all arguments and bind their values to correspondings |
| parameters, making up the NEW_CALL context. */ |
| |
| static tree |
| rs_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, tree fun, |
| bool *non_constant_p, bool *overflow_p, |
| bool *non_constant_args) |
| { |
| const int nargs = call_expr_nargs (t); |
| tree parms = DECL_ARGUMENTS (fun); |
| int i; |
| /* We don't record ellipsis args below. */ |
| int nparms = list_length (parms); |
| int nbinds = nargs < nparms ? nargs : nparms; |
| tree binds = make_tree_vec (nbinds); |
| for (i = 0; i < nargs; ++i) |
| { |
| tree x, arg; |
| tree type = parms ? TREE_TYPE (parms) : void_type_node; |
| if (parms && DECL_BY_REFERENCE (parms)) |
| type = TREE_TYPE (type); |
| x = CALL_EXPR_ARG (t, i); |
| |
| if (TREE_ADDRESSABLE (type)) |
| /* Undo convert_for_arg_passing work here. */ |
| x = convert_from_reference (x); |
| /* Normally we would strip a TARGET_EXPR in an initialization context |
| such as this, but here we do the elision differently: we keep the |
| TARGET_EXPR, and use its CONSTRUCTOR as the value of the parm. */ |
| arg = eval_constant_expression (ctx, x, /*lval=*/false, non_constant_p, |
| overflow_p); |
| /* Don't VERIFY_CONSTANT here. */ |
| if (*non_constant_p && ctx->quiet) |
| break; |
| /* Just discard ellipsis args after checking their constantitude. */ |
| if (!parms) |
| continue; |
| |
| if (!*non_constant_p) |
| { |
| /* Make sure the binding has the same type as the parm. But |
| only for constant args. */ |
| if (!TYPE_REF_P (type)) |
| arg = adjust_temp_type (type, arg); |
| if (!TREE_CONSTANT (arg)) |
| *non_constant_args = true; |
| else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) |
| /* The destructor needs to see any modifications the callee makes |
| to the argument. */ |
| *non_constant_args = true; |
| /* If arg is or contains address of a heap artificial variable or |
| of a static variable being constructed, avoid caching the |
| function call, as those variables might be modified by the |
| function, or might be modified by the callers in between |
| the cached function and just read by the function. */ |
| else if (!*non_constant_args |
| && rs_walk_tree (&arg, addr_of_non_const_var, ctx->global, |
| NULL)) |
| *non_constant_args = true; |
| |
| // /* For virtual calls, adjust the this argument, so that it is |
| // the object on which the method is called, rather than |
| // one of its bases. */ |
| // if (i == 0 && DECL_VIRTUAL_P (fun)) |
| // { |
| // tree addr = arg; |
| // STRIP_NOPS (addr); |
| // if (TREE_CODE (addr) == ADDR_EXPR) |
| // { |
| // tree obj = TREE_OPERAND (addr, 0); |
| // while (TREE_CODE (obj) == COMPONENT_REF |
| // && DECL_FIELD_IS_BASE (TREE_OPERAND (obj, 1)) |
| // && !same_type_ignoring_top_level_qualifiers_p ( |
| // TREE_TYPE (obj), DECL_CONTEXT (fun))) |
| // obj = TREE_OPERAND (obj, 0); |
| // if (obj != TREE_OPERAND (addr, 0)) |
| // arg = build_fold_addr_expr_with_type (obj, TREE_TYPE |
| // (arg)); |
| // } |
| // } |
| TREE_VEC_ELT (binds, i) = arg; |
| } |
| parms = TREE_CHAIN (parms); |
| } |
| |
| return binds; |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_builtin_function_call |
| |
| /* Attempt to evaluate T which represents a call to a builtin function. |
| We assume here that all builtin functions evaluate to scalar types |
| represented by _CST nodes. */ |
| |
| static tree |
| eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun, |
| bool lval, bool *non_constant_p, bool *overflow_p) |
| { |
| const int nargs = call_expr_nargs (t); |
| tree *args = (tree *) alloca (nargs * sizeof (tree)); |
| tree new_call; |
| int i; |
| |
| /* Don't fold __builtin_constant_p within a constexpr function. */ |
| bool bi_const_p = DECL_IS_BUILTIN_CONSTANT_P (fun); |
| |
| /* If we aren't requiring a constant expression, defer __builtin_constant_p |
| in a constexpr function until we have values for the parameters. */ |
| if (bi_const_p && !ctx->manifestly_const_eval && current_function_decl |
| && DECL_DECLARED_CONSTEXPR_P (current_function_decl)) |
| { |
| *non_constant_p = true; |
| return t; |
| } |
| |
| /* For __builtin_is_constant_evaluated, defer it if not |
| ctx->manifestly_const_eval (as sometimes we try to constant evaluate |
| without manifestly_const_eval even expressions or parts thereof which |
| will later be manifestly const_eval evaluated), otherwise fold it to |
| true. */ |
| if (fndecl_built_in_p (fun, CP_BUILT_IN_IS_CONSTANT_EVALUATED, |
| BUILT_IN_FRONTEND)) |
| { |
| if (!ctx->manifestly_const_eval) |
| { |
| *non_constant_p = true; |
| return t; |
| } |
| return boolean_true_node; |
| } |
| |
| if (fndecl_built_in_p (fun, CP_BUILT_IN_SOURCE_LOCATION, BUILT_IN_FRONTEND)) |
| { |
| temp_override<tree> ovr (current_function_decl); |
| if (ctx->call && ctx->call->fundef) |
| current_function_decl = ctx->call->fundef->decl; |
| return fold_builtin_source_location (EXPR_LOCATION (t)); |
| } |
| |
| int strops = 0; |
| int strret = 0; |
| if (fndecl_built_in_p (fun, BUILT_IN_NORMAL)) |
| switch (DECL_FUNCTION_CODE (fun)) |
| { |
| case BUILT_IN_STRLEN: |
| case BUILT_IN_STRNLEN: |
| strops = 1; |
| break; |
| case BUILT_IN_MEMCHR: |
| case BUILT_IN_STRCHR: |
| case BUILT_IN_STRRCHR: |
| strops = 1; |
| strret = 1; |
| break; |
| case BUILT_IN_MEMCMP: |
| case BUILT_IN_STRCMP: |
| strops = 2; |
| break; |
| case BUILT_IN_STRSTR: |
| strops = 2; |
| strret = 1; |
| break; |
| case BUILT_IN_ASAN_POINTER_COMPARE: |
| case BUILT_IN_ASAN_POINTER_SUBTRACT: |
| /* These builtins shall be ignored during constant expression |
| evaluation. */ |
| return void_node; |
| default: |
| break; |
| } |
| |
| /* Be permissive for arguments to built-ins; __builtin_constant_p should |
| return constant false for a non-constant argument. */ |
| constexpr_ctx new_ctx = *ctx; |
| new_ctx.quiet = true; |
| for (i = 0; i < nargs; ++i) |
| { |
| tree arg = CALL_EXPR_ARG (t, i); |
| tree oarg = arg; |
| |
| /* To handle string built-ins we need to pass ADDR_EXPR<STRING_CST> since |
| expand_builtin doesn't know how to look in the values table. */ |
| bool strop = i < strops; |
| if (strop) |
| { |
| STRIP_NOPS (arg); |
| if (TREE_CODE (arg) == ADDR_EXPR) |
| arg = TREE_OPERAND (arg, 0); |
| else |
| strop = false; |
| } |
| |
| /* If builtin_valid_in_constant_expr_p is true, |
| potential_constant_expression_1 has not recursed into the arguments |
| of the builtin, verify it here. */ |
| if (!builtin_valid_in_constant_expr_p (fun) |
| || potential_constant_expression (arg)) |
| { |
| bool dummy1 = false, dummy2 = false; |
| arg |
| = eval_constant_expression (&new_ctx, arg, false, &dummy1, &dummy2); |
| } |
| |
| if (bi_const_p) |
| /* For __builtin_constant_p, fold all expressions with constant values |
| even if they aren't C++ constant-expressions. */ |
| arg = cp_fold_rvalue (arg); |
| else if (strop) |
| { |
| if (TREE_CODE (arg) == CONSTRUCTOR) |
| arg = braced_lists_to_strings (TREE_TYPE (arg), arg); |
| if (TREE_CODE (arg) == STRING_CST) |
| arg = build_address (arg); |
| else |
| arg = oarg; |
| } |
| |
| args[i] = arg; |
| } |
| |
| bool save_ffbcp = force_folding_builtin_constant_p; |
| force_folding_builtin_constant_p |= ctx->manifestly_const_eval; |
| tree save_cur_fn = current_function_decl; |
| /* Return name of ctx->call->fundef->decl for __builtin_FUNCTION (). */ |
| if (fndecl_built_in_p (fun, BUILT_IN_FUNCTION) && ctx->call |
| && ctx->call->fundef) |
| current_function_decl = ctx->call->fundef->decl; |
| if (fndecl_built_in_p (fun, |
| CP_BUILT_IN_IS_POINTER_INTERCONVERTIBLE_WITH_CLASS, |
| BUILT_IN_FRONTEND)) |
| { |
| location_t loc = EXPR_LOCATION (t); |
| if (nargs >= 1) |
| VERIFY_CONSTANT (args[0]); |
| new_call |
| = fold_builtin_is_pointer_inverconvertible_with_class (loc, nargs, |
| args); |
| } |
| else if (fndecl_built_in_p (fun, CP_BUILT_IN_IS_CORRESPONDING_MEMBER, |
| BUILT_IN_FRONTEND)) |
| { |
| location_t loc = EXPR_LOCATION (t); |
| if (nargs >= 2) |
| { |
| VERIFY_CONSTANT (args[0]); |
| VERIFY_CONSTANT (args[1]); |
| } |
| new_call = fold_builtin_is_corresponding_member (loc, nargs, args); |
| } |
| else |
| new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t), |
| CALL_EXPR_FN (t), nargs, args); |
| current_function_decl = save_cur_fn; |
| force_folding_builtin_constant_p = save_ffbcp; |
| if (new_call == NULL) |
| { |
| if (!*non_constant_p && !ctx->quiet) |
| { |
| /* Do not allow__builtin_unreachable in constexpr function. |
| The __builtin_unreachable call with BUILTINS_LOCATION |
| comes from cp_maybe_instrument_return. */ |
| if (fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE) |
| && EXPR_LOCATION (t) == BUILTINS_LOCATION) |
| error ("%<constexpr%> call flows off the end of the function"); |
| else |
| { |
| new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t), |
| CALL_EXPR_FN (t), nargs, args); |
| error ("%q+E is not a constant expression", new_call); |
| } |
| } |
| *non_constant_p = true; |
| return t; |
| } |
| |
| if (!potential_constant_expression (new_call)) |
| { |
| if (!*non_constant_p && !ctx->quiet) |
| error ("%q+E is not a constant expression", new_call); |
| *non_constant_p = true; |
| return t; |
| } |
| |
| if (strret) |
| { |
| /* memchr returns a pointer into the first argument, but we replaced the |
| argument above with a STRING_CST; put it back it now. */ |
| tree op = CALL_EXPR_ARG (t, strret - 1); |
| STRIP_NOPS (new_call); |
| if (TREE_CODE (new_call) == POINTER_PLUS_EXPR) |
| TREE_OPERAND (new_call, 0) = op; |
| else if (TREE_CODE (new_call) == ADDR_EXPR) |
| new_call = op; |
| } |
| |
| return eval_constant_expression (&new_ctx, new_call, lval, non_constant_p, |
| overflow_p); |
| } |
| |
| // Subroutine of cxx_eval_constant_expression. |
| // Evaluate the call expression tree T in the context of OLD_CALL expression |
| // evaluation. |
| static tree |
| eval_call_expression (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| location_t loc = EXPR_LOCATION (t); |
| tree fun = get_function_named_in_call (t); |
| rust_constexpr_call new_call |
| = {NULL, NULL, NULL, 0, ctx->manifestly_const_eval}; |
| int depth_ok; |
| |
| if (fun == NULL_TREE) |
| { |
| // return cxx_eval_internal_function (ctx, t, lval, |
| // non_constant_p, overflow_p); |
| rust_unreachable (); |
| return error_mark_node; |
| } |
| |
| if (TREE_CODE (fun) != FUNCTION_DECL) |
| { |
| if (!ctx->quiet && !*non_constant_p) |
| error_at (loc, |
| "expression %qE does not designate a %<constexpr%> " |
| "function", |
| fun); |
| *non_constant_p = true; |
| return t; |
| } |
| |
| if (fndecl_built_in_p (fun)) |
| return eval_builtin_function_call (ctx, t, fun, lval, non_constant_p, |
| overflow_p); |
| |
| bool non_constant_args = false; |
| new_call.bindings |
| = rs_bind_parameters_in_call (ctx, t, fun, non_constant_p, overflow_p, |
| &non_constant_args); |
| |
| /* We build up the bindings list before we know whether we already have this |
| call cached. If we don't end up saving these bindings, ggc_free them when |
| this function exits. */ |
| class free_bindings |
| { |
| tree *bindings; |
| |
| public: |
| free_bindings (tree &b) : bindings (&b) {} |
| ~free_bindings () |
| { |
| if (bindings) |
| ggc_free (*bindings); |
| } |
| void preserve () { bindings = NULL; } |
| } fb (new_call.bindings); |
| |
| if (*non_constant_p) |
| return t; |
| |
| /* If in direct recursive call, optimize definition search. */ |
| if (ctx && ctx->call && ctx->call->fundef && ctx->call->fundef->decl == fun) |
| new_call.fundef = ctx->call->fundef; |
| else |
| { |
| new_call.fundef = retrieve_constexpr_fundef (fun); |
| if (new_call.fundef == NULL || new_call.fundef->body == NULL |
| || new_call.fundef->result == error_mark_node |
| || fun == current_function_decl) |
| { |
| if (!ctx->quiet) |
| { |
| /* We need to check for current_function_decl here in case we're |
| being called during cp_fold_function, because at that point |
| DECL_INITIAL is set properly and we have a fundef but we |
| haven't lowered invisirefs yet (c++/70344). */ |
| if (DECL_INITIAL (fun) == error_mark_node |
| || fun == current_function_decl) |
| error_at (loc, |
| "%qD called in a constant expression before its " |
| "definition is complete", |
| fun); |
| else if (DECL_INITIAL (fun)) |
| { |
| // /* The definition of fun was somehow unsuitable. But |
| // pretend |
| // that lambda static thunks don't exist. */ |
| // if (!lambda_static_thunk_p (fun)) |
| // error_at (loc, "%qD called in a constant expression", |
| // fun); |
| explain_invalid_constexpr_fn (fun); |
| } |
| else |
| error_at (loc, "%qD used before its definition", fun); |
| } |
| *non_constant_p = true; |
| return t; |
| } |
| } |
| |
| depth_ok = push_cx_call_context (t); |
| |
| tree result = NULL_TREE; |
| rust_constexpr_call *entry = NULL; |
| if (depth_ok && !non_constant_args && ctx->strict) |
| { |
| new_call.hash = rust_constexpr_fundef_hasher::hash (new_call.fundef); |
| new_call.hash = iterative_hash_object (new_call.bindings, new_call.hash); |
| new_call.hash |
| = iterative_hash_object (ctx->manifestly_const_eval, new_call.hash); |
| |
| /* If we have seen this call before, we are done. */ |
| maybe_initialize_constexpr_call_table (); |
| rust_constexpr_call **slot |
| = constexpr_call_table->find_slot (&new_call, INSERT); |
| entry = *slot; |
| if (entry == NULL) |
| { |
| /* Only cache up to constexpr_cache_depth to limit memory use. */ |
| if (depth_ok < constexpr_cache_depth) |
| { |
| /* We need to keep a pointer to the entry, not just the slot, as |
| the slot can move during evaluation of the body. */ |
| *slot = entry = ggc_alloc<rust_constexpr_call> (); |
| *entry = new_call; |
| fb.preserve (); |
| } |
| } |
| /* Calls that are in progress have their result set to NULL, so that we |
| can detect circular dependencies. Now that we only cache up to |
| constexpr_cache_depth this won't catch circular dependencies that |
| start deeper, but they'll hit the recursion or ops limit. */ |
| else if (entry->result == NULL) |
| { |
| if (!ctx->quiet) |
| error ("call has circular dependency"); |
| *non_constant_p = true; |
| entry->result = result = error_mark_node; |
| } |
| else |
| result = entry->result; |
| } |
| |
| if (!depth_ok) |
| { |
| if (!ctx->quiet) |
| error ("%<constexpr%> evaluation depth exceeds maximum of %d (use " |
| "%<-fconstexpr-depth=%> to increase the maximum)", |
| max_constexpr_depth); |
| *non_constant_p = true; |
| result = error_mark_node; |
| } |
| else |
| { |
| bool cacheable = true; |
| if (result && result != error_mark_node) |
| /* OK */; |
| else if (!DECL_SAVED_TREE (fun)) |
| { |
| /* When at_eof >= 2, cgraph has started throwing away |
| DECL_SAVED_TREE, so fail quietly. FIXME we get here because of |
| late code generation for VEC_INIT_EXPR, which needs to be |
| completely reconsidered. */ |
| // gcc_assert (at_eof >= 2 && ctx->quiet); |
| *non_constant_p = true; |
| } |
| else if (tree copy = get_fundef_copy (new_call.fundef)) |
| { |
| tree body, parms, res; |
| releasing_vec ctors; |
| |
| /* Reuse or create a new unshared copy of this function's body. */ |
| body = TREE_PURPOSE (copy); |
| parms = TREE_VALUE (copy); |
| res = TREE_TYPE (copy); |
| |
| /* Associate the bindings with the remapped parms. */ |
| tree bound = new_call.bindings; |
| tree remapped = parms; |
| for (int i = 0; i < TREE_VEC_LENGTH (bound); ++i) |
| { |
| tree arg = TREE_VEC_ELT (bound, i); |
| if (entry) |
| { |
| /* Unshare args going into the hash table to separate them |
| from the caller's context, for better GC and to avoid |
| problems with verify_gimple. */ |
| arg = unshare_expr_without_location (arg); |
| TREE_VEC_ELT (bound, i) = arg; |
| |
| /* And then unshare again so the callee doesn't change the |
| argument values in the hash table. XXX Could we unshare |
| lazily in cxx_eval_store_expression? */ |
| arg = unshare_constructor (arg); |
| if (TREE_CODE (arg) == CONSTRUCTOR) |
| vec_safe_push (ctors, arg); |
| } |
| |
| ctx->global->values.put (remapped, arg); |
| remapped = DECL_CHAIN (remapped); |
| } |
| /* Add the RESULT_DECL to the values map, too. */ |
| gcc_assert (!DECL_BY_REFERENCE (res)); |
| ctx->global->values.put (res, NULL_TREE); |
| |
| /* Track the callee's evaluated SAVE_EXPRs and TARGET_EXPRs so that |
| we can forget their values after the call. */ |
| constexpr_ctx ctx_with_save_exprs = *ctx; |
| auto_vec<tree, 10> save_exprs; |
| ctx_with_save_exprs.save_exprs = &save_exprs; |
| ctx_with_save_exprs.call = &new_call; |
| unsigned save_heap_alloc_count = ctx->global->heap_vars.length (); |
| unsigned save_heap_dealloc_count = ctx->global->heap_dealloc_count; |
| |
| tree jump_target = NULL_TREE; |
| eval_constant_expression (&ctx_with_save_exprs, body, lval, |
| non_constant_p, overflow_p, &jump_target); |
| |
| if (VOID_TYPE_P (TREE_TYPE (res))) |
| result = void_node; |
| else |
| { |
| result = *ctx->global->values.get (res); |
| if (result == NULL_TREE && !*non_constant_p) |
| { |
| if (!ctx->quiet) |
| error ("%<constexpr%> call flows off the end " |
| "of the function"); |
| *non_constant_p = true; |
| } |
| } |
| |
| /* Forget the saved values of the callee's SAVE_EXPRs and |
| TARGET_EXPRs. */ |
| for (tree save_expr : save_exprs) |
| ctx->global->values.remove (save_expr); |
| |
| /* Remove the parms/result from the values map. Is it worth |
| bothering to do this when the map itself is only live for |
| one constexpr evaluation? If so, maybe also clear out |
| other vars from call, maybe in BIND_EXPR handling? */ |
| ctx->global->values.remove (res); |
| for (tree parm = parms; parm; parm = TREE_CHAIN (parm)) |
| ctx->global->values.remove (parm); |
| |
| /* Make the unshared function copy we used available for re-use. */ |
| save_fundef_copy (fun, copy); |
| |
| /* If the call allocated some heap object that hasn't been |
| deallocated during the call, or if it deallocated some heap |
| object it has not allocated, the call isn't really stateless |
| for the constexpr evaluation and should not be cached. |
| It is fine if the call allocates something and deallocates it |
| too. */ |
| if (entry |
| && (save_heap_alloc_count != ctx->global->heap_vars.length () |
| || (save_heap_dealloc_count |
| != ctx->global->heap_dealloc_count))) |
| { |
| tree heap_var; |
| unsigned int i; |
| if ((ctx->global->heap_vars.length () |
| - ctx->global->heap_dealloc_count) |
| != save_heap_alloc_count - save_heap_dealloc_count) |
| cacheable = false; |
| else |
| FOR_EACH_VEC_ELT_FROM (ctx->global->heap_vars, i, heap_var, |
| save_heap_alloc_count) |
| if (DECL_NAME (heap_var) != heap_deleted_identifier) |
| { |
| cacheable = false; |
| break; |
| } |
| } |
| } |
| else |
| /* Couldn't get a function copy to evaluate. */ |
| *non_constant_p = true; |
| |
| if (result == error_mark_node) |
| *non_constant_p = true; |
| if (*non_constant_p || *overflow_p) |
| result = error_mark_node; |
| else if (!result) |
| result = void_node; |
| if (entry) |
| entry->result = cacheable ? result : error_mark_node; |
| } |
| |
| pop_cx_call_context (); |
| return result; |
| } |
| |
| /* Subroutine of build_data_member_initialization. MEMBER is a COMPONENT_REF |
| for a member of an anonymous aggregate, INIT is the initializer for that |
| member, and VEC_OUTER is the vector of constructor elements for the class |
| whose constructor we are processing. Add the initializer to the vector |
| and return true to indicate success. */ |
| |
| // static bool |
| // build_anon_member_initialization (tree member, tree init, |
| // vec<constructor_elt, va_gc> **vec_outer) |
| // { |
| // /* MEMBER presents the relevant fields from the inside out, but we need |
| // to build up the initializer from the outside in so that we can reuse |
| // previously built CONSTRUCTORs if this is, say, the second field in an |
| // anonymous struct. So we use a vec as a stack. */ |
| // auto_vec<tree, 2> fields; |
| // do |
| // { |
| // fields.safe_push (TREE_OPERAND (member, 1)); |
| // member = TREE_OPERAND (member, 0); |
| // } while (ANON_AGGR_TYPE_P (TREE_TYPE (member)) |
| // && TREE_CODE (member) == COMPONENT_REF); |
| // |
| // /* VEC has the constructor elements vector for the context of FIELD. |
| // If FIELD is an anonymous aggregate, we will push inside it. */ |
| // vec<constructor_elt, va_gc> **vec = vec_outer; |
| // tree field; |
| // while (field = fields.pop (), ANON_AGGR_TYPE_P (TREE_TYPE (field))) |
| // { |
| // tree ctor; |
| // /* If there is already an outer constructor entry for the anonymous |
| // aggregate FIELD, use it; otherwise, insert one. */ |
| // if (vec_safe_is_empty (*vec) || (*vec)->last ().index != field) |
| // { |
| // ctor = build_constructor (TREE_TYPE (field), NULL); |
| // CONSTRUCTOR_APPEND_ELT (*vec, field, ctor); |
| // } |
| // else |
| // ctor = (*vec)->last ().value; |
| // vec = &CONSTRUCTOR_ELTS (ctor); |
| // } |
| // |
| // /* Now we're at the innermost field, the one that isn't an anonymous |
| // aggregate. Add its initializer to the CONSTRUCTOR and we're done. */ |
| // gcc_assert (fields.is_empty ()); |
| // CONSTRUCTOR_APPEND_ELT (*vec, field, init); |
| // |
| // return true; |
| // } |
| |
| ///* V is a vector of constructor elements built up for the base and member |
| // initializers of a constructor for TYPE. They need to be in increasing |
| // offset order, which they might not be yet if TYPE has a primary base |
| // which is not first in the base-clause or a vptr and at least one base |
| // all of which are non-primary. */ |
| // |
| // static vec<constructor_elt, va_gc> * |
| // sort_constexpr_mem_initializers (tree type, vec<constructor_elt, va_gc> *v) |
| //{ |
| // tree pri = CLASSTYPE_PRIMARY_BINFO (type); |
| // tree field_type; |
| // unsigned i; |
| // constructor_elt *ce; |
| // |
| // if (pri) |
| // field_type = BINFO_TYPE (pri); |
| // else if (TYPE_CONTAINS_VPTR_P (type)) |
| // field_type = vtbl_ptr_type_node; |
| // else |
| // return v; |
| // |
| // /* Find the element for the primary base or vptr and move it to the |
| // beginning of the vec. */ |
| // for (i = 0; vec_safe_iterate (v, i, &ce); ++i) |
| // if (TREE_TYPE (ce->index) == field_type) |
| // break; |
| // |
| // if (i > 0 && i < vec_safe_length (v)) |
| // { |
| // vec<constructor_elt, va_gc> &vref = *v; |
| // constructor_elt elt = vref[i]; |
| // for (; i > 0; --i) |
| // vref[i] = vref[i - 1]; |
| // vref[0] = elt; |
| // } |
| // |
| // return v; |
| //} |
| |
| /* Subroutine of build_constexpr_constructor_member_initializers. |
| The expression tree T represents a data member initialization |
| in a (constexpr) constructor definition. Build a pairing of |
| the data member with its initializer, and prepend that pair |
| to the existing initialization pair INITS. */ |
| |
| static bool |
| build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec) |
| { |
| tree member; |
| if (TREE_CODE (t) == CLEANUP_POINT_EXPR) |
| t = TREE_OPERAND (t, 0); |
| if (TREE_CODE (t) == EXPR_STMT) |
| t = TREE_OPERAND (t, 0); |
| if (t == error_mark_node) |
| return false; |
| if (TREE_CODE (t) == STATEMENT_LIST) |
| { |
| for (tree stmt : tsi_range (t)) |
| if (!build_data_member_initialization (stmt, vec)) |
| return false; |
| return true; |
| } |
| if (TREE_CODE (t) == CONVERT_EXPR) |
| t = TREE_OPERAND (t, 0); |
| if (TREE_CODE (t) == INIT_EXPR |
| /* vptr initialization shows up as a MODIFY_EXPR. In C++14 we only |
| use what this function builds for cx_check_missing_mem_inits, and |
| assignment in the ctor body doesn't count. */ |
| || (TREE_CODE (t) == MODIFY_EXPR)) |
| { |
| member = TREE_OPERAND (t, 0); |
| // Faisal: not sure if we need to port over break_out_target_exprs |
| // if not, then not sure how to handle init in this case |
| // init = break_out_target_exprs (TREE_OPERAND (t, 1)); |
| } |
| else if (TREE_CODE (t) == CALL_EXPR) |
| { |
| tree fn = get_callee_fndecl (t); |
| if (!fn || !DECL_CONSTRUCTOR_P (fn)) |
| /* We're only interested in calls to subobject constructors. */ |
| return true; |
| member = CALL_EXPR_ARG (t, 0); |
| /* We don't use build_cplus_new here because it complains about |
| abstract bases. Leaving the call unwrapped means that it has the |
| wrong type, but cxx_eval_constant_expression doesn't care. */ |
| // Faisal: not sure if we need to port over break_out_target_exprs |
| // if not, then not sure how to handle init in this case |
| // init = break_out_target_exprs (t); |
| } |
| else if (TREE_CODE (t) == BIND_EXPR) |
| return build_data_member_initialization (BIND_EXPR_BODY (t), vec); |
| else |
| /* Don't add anything else to the CONSTRUCTOR. */ |
| return true; |
| if (INDIRECT_REF_P (member)) |
| member = TREE_OPERAND (member, 0); |
| if (TREE_CODE (member) == NOP_EXPR) |
| { |
| tree op = member; |
| STRIP_NOPS (op); |
| if (TREE_CODE (op) == ADDR_EXPR) |
| { |
| gcc_assert (same_type_ignoring_top_level_qualifiers_p ( |
| TREE_TYPE (TREE_TYPE (op)), TREE_TYPE (TREE_TYPE (member)))); |
| /* Initializing a cv-qualified member; we need to look through |
| the const_cast. */ |
| member = op; |
| } |
| else if (op == current_class_ptr |
| && (same_type_ignoring_top_level_qualifiers_p ( |
| TREE_TYPE (TREE_TYPE (member)), current_class_type))) |
| /* Delegating constructor. */ |
| member = op; |
| else |
| { |
| /* This is an initializer for an empty base; keep it for now so |
| we can check it in cxx_eval_bare_aggregate. */ |
| gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (member)))); |
| } |
| } |
| if (TREE_CODE (member) == ADDR_EXPR) |
| member = TREE_OPERAND (member, 0); |
| if (TREE_CODE (member) == COMPONENT_REF) |
| { |
| tree aggr = TREE_OPERAND (member, 0); |
| if (TREE_CODE (aggr) == VAR_DECL) |
| /* Initializing a local variable, don't add anything. */ |
| return true; |
| if (TREE_CODE (aggr) != COMPONENT_REF) |
| /* Normal member initialization. */ |
| member = TREE_OPERAND (member, 1); |
| else if (ANON_AGGR_TYPE_P (TREE_TYPE (aggr))) |
| /* Initializing a member of an anonymous union. */ |
| rust_sorry_at (UNDEF_LOCATION, |
| "cannot handle value initialization yet"); |
| // return build_anon_member_initialization (member, init, vec); |
| else |
| /* We're initializing a vtable pointer in a base. Leave it as |
| COMPONENT_REF so we remember the path to get to the vfield. */ |
| gcc_assert (TREE_TYPE (member) == vtbl_ptr_type_node); |
| } |
| |
| /* Value-initialization can produce multiple initializers for the |
| same field; use the last one. */ |
| if (!vec_safe_is_empty (*vec) && (*vec)->last ().index == member) |
| rust_sorry_at (UNDEF_LOCATION, "cannot handle value initialization yet"); |
| // (*vec)->last ().value = init; |
| else |
| rust_sorry_at (UNDEF_LOCATION, "cannot handle value initialization yet"); |
| // CONSTRUCTOR_APPEND_ELT (*vec, member, init); |
| return true; |
| } |
| |
| ///* Build compile-time evalable representations of member-initializer list |
| // for a constexpr constructor. */ |
| // |
| // static tree |
| // build_constexpr_constructor_member_initializers (tree type, tree body) |
| //{ |
| // vec<constructor_elt, va_gc> *vec = NULL; |
| // bool ok = true; |
| // while (true) |
| // switch (TREE_CODE (body)) |
| // { |
| // case STATEMENT_LIST: |
| // for (tree stmt : tsi_range (body)) |
| // { |
| // body = stmt; |
| // if (TREE_CODE (body) == BIND_EXPR) |
| // break; |
| // } |
| // break; |
| // |
| // case BIND_EXPR: |
| // body = BIND_EXPR_BODY (body); |
| // goto found; |
| // |
| // default: |
| // rust_unreachable (); |
| // } |
| // found: |
| // |
| // if (TREE_CODE (body) == CLEANUP_POINT_EXPR) |
| // { |
| // body = TREE_OPERAND (body, 0); |
| // if (TREE_CODE (body) == EXPR_STMT) |
| // body = TREE_OPERAND (body, 0); |
| // if (TREE_CODE (body) == INIT_EXPR |
| // && (same_type_ignoring_top_level_qualifiers_p ( |
| // TREE_TYPE (TREE_OPERAND (body, 0)), current_class_type))) |
| // { |
| // /* Trivial copy. */ |
| // return TREE_OPERAND (body, 1); |
| // } |
| // ok = build_data_member_initialization (body, &vec); |
| // } |
| // else if (TREE_CODE (body) == STATEMENT_LIST) |
| // { |
| // for (tree stmt : tsi_range (body)) |
| // { |
| // ok = build_data_member_initialization (stmt, &vec); |
| // if (!ok) |
| // break; |
| // } |
| // } |
| // else if (EXPR_P (body)) |
| // ok = build_data_member_initialization (body, &vec); |
| // else |
| // gcc_assert (errorcount > 0); |
| // if (ok) |
| // { |
| // if (vec_safe_length (vec) > 0) |
| // { |
| // /* In a delegating constructor, return the target. */ |
| // constructor_elt *ce = &(*vec)[0]; |
| // if (ce->index == current_class_ptr) |
| // { |
| // body = ce->value; |
| // vec_free (vec); |
| // return body; |
| // } |
| // } |
| // vec = sort_constexpr_mem_initializers (type, vec); |
| // return build_constructor (type, vec); |
| // } |
| // else |
| // return error_mark_node; |
| //} |
| |
| // Subroutine of check_constexpr_fundef. BODY is the body of a function |
| // declared to be constexpr, or a sub-statement thereof. Returns the |
| // return value if suitable, error_mark_node for a statement not allowed in |
| // a constexpr function, or NULL_TREE if no return value was found. |
| static tree |
| constexpr_fn_retval (const constexpr_ctx *ctx, tree body) |
| { |
| switch (TREE_CODE (body)) |
| { |
| case STATEMENT_LIST: { |
| tree expr = NULL_TREE; |
| for (tree stmt : tsi_range (body)) |
| { |
| tree s = constexpr_fn_retval (ctx, stmt); |
| if (s == error_mark_node) |
| return error_mark_node; |
| else if (s == NULL_TREE) |
| /* Keep iterating. */; |
| else if (expr) |
| /* Multiple return statements. */ |
| return error_mark_node; |
| else |
| expr = s; |
| } |
| return expr; |
| } |
| |
| case RETURN_EXPR: { |
| bool non_constant_p = false; |
| bool overflow_p = false; |
| return eval_constant_expression (ctx, body, false, &non_constant_p, |
| &overflow_p); |
| } |
| case DECL_EXPR: { |
| tree decl = DECL_EXPR_DECL (body); |
| if (TREE_CODE (decl) == USING_DECL |
| /* Accept __func__, __FUNCTION__, and __PRETTY_FUNCTION__. */ |
| || DECL_ARTIFICIAL (decl)) |
| return NULL_TREE; |
| return error_mark_node; |
| } |
| |
| case CLEANUP_POINT_EXPR: |
| return constexpr_fn_retval (ctx, TREE_OPERAND (body, 0)); |
| |
| case BIND_EXPR: { |
| tree b = BIND_EXPR_BODY (body); |
| return constexpr_fn_retval (ctx, b); |
| } |
| break; |
| |
| default: |
| return error_mark_node; |
| } |
| return error_mark_node; |
| } |
| |
| // Taken from cp/constexpr.cc |
| // |
| // If DECL is a scalar enumeration constant or variable with a |
| // constant initializer, return the initializer (or, its initializers, |
| // recursively); otherwise, return DECL. If STRICT_P, the |
| // initializer is only returned if DECL is a |
| // constant-expression. If RETURN_AGGREGATE_CST_OK_P, it is ok to |
| // return an aggregate constant. If UNSHARE_P, return an unshared |
| // copy of the initializer. |
| static tree |
| constant_value_1 (tree decl, bool, bool, bool unshare_p) |
| { |
| while (TREE_CODE (decl) == CONST_DECL) |
| { |
| tree init; |
| /* If DECL is a static data member in a template |
| specialization, we must instantiate it here. The |
| initializer for the static data member is not processed |
| until needed; we need it now. */ |
| |
| init = DECL_INITIAL (decl); |
| if (init == error_mark_node) |
| { |
| if (TREE_CODE (decl) == CONST_DECL) |
| /* Treat the error as a constant to avoid cascading errors on |
| excessively recursive template instantiation (c++/9335). */ |
| return init; |
| else |
| return decl; |
| } |
| |
| decl = init; |
| } |
| return unshare_p ? unshare_expr (decl) : decl; |
| } |
| |
| // A more relaxed version of decl_really_constant_value, used by the |
| // common C/C++ code. |
| tree |
| decl_constant_value (tree decl, bool unshare_p) |
| { |
| return constant_value_1 (decl, /*strict_p=*/false, |
| /*return_aggregate_cst_ok_p=*/true, |
| /*unshare_p=*/unshare_p); |
| } |
| |
| static void |
| non_const_var_error (location_t loc, tree r) |
| { |
| error_at (loc, |
| "the value of %qD is not usable in a constant " |
| "expression", |
| r); |
| /* Avoid error cascade. */ |
| if (DECL_INITIAL (r) == error_mark_node) |
| return; |
| |
| // more in cp/constexpr.cc |
| } |
| |
| static tree |
| get_callee (tree call) |
| { |
| if (call == NULL_TREE) |
| return call; |
| else if (TREE_CODE (call) == CALL_EXPR) |
| return CALL_EXPR_FN (call); |
| |
| return NULL_TREE; |
| } |
| |
| // We have an expression tree T that represents a call, either CALL_EXPR |
| // or AGGR_INIT_EXPR. If the call is lexically to a named function, |
| // return the _DECL for that function. |
| static tree |
| get_function_named_in_call (tree t) |
| { |
| tree fun = get_callee (t); |
| if (fun && TREE_CODE (fun) == ADDR_EXPR |
| && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) |
| fun = TREE_OPERAND (fun, 0); |
| return fun; |
| } |
| |
| // forked from gcc/cp/constexpr.cc maybe_constexpr_fn |
| |
| /* True if a function might be declared constexpr */ |
| |
| bool |
| maybe_constexpr_fn (tree t) |
| { |
| return (DECL_DECLARED_CONSTEXPR_P (t)); |
| } |
| |
| // forked from gcc/cp/constexpr.cc var_in_maybe_constexpr_fn |
| |
| /* True if T was declared in a function that might be constexpr: either a |
| function that was declared constexpr. */ |
| |
| bool |
| var_in_maybe_constexpr_fn (tree t) |
| { |
| return (DECL_FUNCTION_SCOPE_P (t) && maybe_constexpr_fn (DECL_CONTEXT (t))); |
| } |
| |
| /* P0859: A function is needed for constant evaluation if it is a constexpr |
| function that is named by an expression ([basic.def.odr]) that is |
| potentially constant evaluated. |
| |
| So we need to instantiate any constexpr functions mentioned by the |
| expression even if the definition isn't needed for evaluating the |
| expression. */ |
| |
| static tree |
| instantiate_cx_fn_r (tree *tp, int *walk_subtrees, void * /*data*/) |
| { |
| if (TREE_CODE (*tp) == CALL_EXPR) |
| { |
| if (EXPR_HAS_LOCATION (*tp)) |
| input_location = EXPR_LOCATION (*tp); |
| } |
| |
| if (!EXPR_P (*tp)) |
| *walk_subtrees = 0; |
| |
| return NULL_TREE; |
| } |
| |
| static void |
| instantiate_constexpr_fns (tree t) |
| { |
| location_t loc = input_location; |
| rs_walk_tree_without_duplicates (&t, instantiate_cx_fn_r, NULL); |
| input_location = loc; |
| } |
| |
| /* Returns less than, equal to, or greater than zero if KEY is found to be |
| less than, to match, or to be greater than the constructor_elt's INDEX. */ |
| |
| static int |
| array_index_cmp (tree key, tree index) |
| { |
| gcc_assert (TREE_CODE (key) == INTEGER_CST); |
| |
| switch (TREE_CODE (index)) |
| { |
| case INTEGER_CST: |
| return tree_int_cst_compare (key, index); |
| case RANGE_EXPR: { |
| tree lo = TREE_OPERAND (index, 0); |
| tree hi = TREE_OPERAND (index, 1); |
| if (tree_int_cst_lt (key, lo)) |
| return -1; |
| else if (tree_int_cst_lt (hi, key)) |
| return 1; |
| else |
| return 0; |
| } |
| default: |
| rust_unreachable (); |
| } |
| } |
| |
| /* If T is a CONSTRUCTOR, return an unshared copy of T and any |
| sub-CONSTRUCTORs. Otherwise return T. |
| |
| We use this whenever we initialize an object as a whole, whether it's a |
| parameter, a local variable, or a subobject, so that subsequent |
| modifications don't affect other places where it was used. */ |
| |
| tree |
| unshare_constructor (tree t MEM_STAT_DECL) |
| { |
| if (!t || TREE_CODE (t) != CONSTRUCTOR) |
| return t; |
| auto_vec<tree *, 4> ptrs; |
| ptrs.safe_push (&t); |
| while (!ptrs.is_empty ()) |
| { |
| tree *p = ptrs.pop (); |
| tree n = copy_node (*p PASS_MEM_STAT); |
| CONSTRUCTOR_ELTS (n) |
| = vec_safe_copy (CONSTRUCTOR_ELTS (*p) PASS_MEM_STAT); |
| *p = n; |
| vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (n); |
| constructor_elt *ce; |
| for (HOST_WIDE_INT i = 0; vec_safe_iterate (v, i, &ce); ++i) |
| if (ce->value && TREE_CODE (ce->value) == CONSTRUCTOR) |
| ptrs.safe_push (&ce->value); |
| } |
| return t; |
| } |
| |
| /* Returns the index of the constructor_elt of ARY which matches DINDEX, or -1 |
| if none. If INSERT is true, insert a matching element rather than fail. */ |
| |
| static HOST_WIDE_INT |
| find_array_ctor_elt (tree ary, tree dindex, bool insert) |
| { |
| if (tree_int_cst_sgn (dindex) < 0) |
| return -1; |
| |
| unsigned HOST_WIDE_INT i = tree_to_uhwi (dindex); |
| vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ary); |
| unsigned HOST_WIDE_INT len = vec_safe_length (elts); |
| |
| unsigned HOST_WIDE_INT end = len; |
| unsigned HOST_WIDE_INT begin = 0; |
| |
| /* If the last element of the CONSTRUCTOR has its own index, we can assume |
| that the same is true of the other elements and index directly. */ |
| if (end > 0) |
| { |
| tree cindex = (*elts)[end - 1].index; |
| if (cindex == NULL_TREE) |
| { |
| /* Verify that if the last index is missing, all indexes |
| are missing. */ |
| if (flag_checking) |
| for (unsigned int j = 0; j < len - 1; ++j) |
| gcc_assert ((*elts)[j].index == NULL_TREE); |
| if (i < end) |
| return i; |
| else |
| { |
| begin = end; |
| if (i == end) |
| /* If the element is to be added right at the end, |
| make sure it is added with cleared index too. */ |
| dindex = NULL_TREE; |
| else if (insert) |
| /* Otherwise, in order not to break the assumption |
| that CONSTRUCTOR either has all indexes or none, |
| we need to add indexes to all elements. */ |
| for (unsigned int j = 0; j < len; ++j) |
| (*elts)[j].index = build_int_cst (TREE_TYPE (dindex), j); |
| } |
| } |
| else if (TREE_CODE (cindex) == INTEGER_CST |
| && compare_tree_int (cindex, end - 1) == 0) |
| { |
| if (i < end) |
| return i; |
| else |
| begin = end; |
| } |
| } |
| |
| /* Otherwise, find a matching index by means of a binary search. */ |
| while (begin != end) |
| { |
| unsigned HOST_WIDE_INT middle = (begin + end) / 2; |
| constructor_elt &elt = (*elts)[middle]; |
| tree idx = elt.index; |
| |
| int cmp = array_index_cmp (dindex, idx); |
| if (cmp < 0) |
| end = middle; |
| else if (cmp > 0) |
| begin = middle + 1; |
| else |
| { |
| if (insert && TREE_CODE (idx) == RANGE_EXPR) |
| { |
| /* We need to split the range. */ |
| constructor_elt e; |
| tree lo = TREE_OPERAND (idx, 0); |
| tree hi = TREE_OPERAND (idx, 1); |
| tree value = elt.value; |
| dindex = fold_convert (sizetype, dindex); |
| if (tree_int_cst_lt (lo, dindex)) |
| { |
| /* There are still some lower elts; shorten the range. */ |
| tree new_hi |
| = int_const_binop (MINUS_EXPR, dindex, size_one_node); |
| if (tree_int_cst_equal (lo, new_hi)) |
| /* Only one element left, no longer a range. */ |
| elt.index = lo; |
| else |
| TREE_OPERAND (idx, 1) = new_hi; |
| /* Append the element we want to insert. */ |
| ++middle; |
| e.index = dindex; |
| e.value = unshare_constructor (value); |
| vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle, e); |
| } |
| else |
| /* No lower elts, the range elt is now ours. */ |
| elt.index = dindex; |
| |
| if (tree_int_cst_lt (dindex, hi)) |
| { |
| /* There are still some higher elts; append a range. */ |
| tree new_lo |
| = int_const_binop (PLUS_EXPR, dindex, size_one_node); |
| if (tree_int_cst_equal (new_lo, hi)) |
| e.index = hi; |
| else |
| e.index = build2 (RANGE_EXPR, sizetype, new_lo, hi); |
| e.value = unshare_constructor (value); |
| vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle + 1, e); |
| } |
| } |
| return middle; |
| } |
| } |
| |
| if (insert) |
| { |
| constructor_elt e = {dindex, NULL_TREE}; |
| vec_safe_insert (CONSTRUCTOR_ELTS (ary), end, e); |
| return end; |
| } |
| |
| return -1; |
| } |
| |
| /* Some expressions may have constant operands but are not constant |
| themselves, such as 1/0. Call this function to check for that |
| condition. |
| |
| We only call this in places that require an arithmetic constant, not in |
| places where we might have a non-constant expression that can be a |
| component of a constant expression, such as the address of a constexpr |
| variable that might be dereferenced later. */ |
| |
| static bool |
| verify_constant (tree t, bool allow_non_constant, bool *non_constant_p, |
| bool *overflow_p) |
| { |
| if (!*non_constant_p && !reduced_constant_expression_p (t) && t != void_node) |
| { |
| if (!allow_non_constant) |
| error ("%q+E is not a constant expression", t); |
| *non_constant_p = true; |
| } |
| if (TREE_OVERFLOW_P (t)) |
| { |
| if (!allow_non_constant) |
| { |
| permerror (input_location, "overflow in constant expression"); |
| /* If we're being permissive (and are in an enforcing |
| context), ignore the overflow. */ |
| if (flag_permissive) |
| return *non_constant_p; |
| } |
| *overflow_p = true; |
| } |
| return *non_constant_p; |
| } |
| |
| // forked from gcc/cp/constexpr.cc find_heap_var_refs |
| |
| /* Look for heap variables in the expression *TP. */ |
| |
| static tree |
| find_heap_var_refs (tree *tp, int *walk_subtrees, void * /*data*/) |
| { |
| if (VAR_P (*tp) |
| && (DECL_NAME (*tp) == heap_uninit_identifier |
| || DECL_NAME (*tp) == heap_identifier |
| || DECL_NAME (*tp) == heap_vec_uninit_identifier |
| || DECL_NAME (*tp) == heap_vec_identifier |
| || DECL_NAME (*tp) == heap_deleted_identifier)) |
| return *tp; |
| |
| if (TYPE_P (*tp)) |
| *walk_subtrees = 0; |
| return NULL_TREE; |
| } |
| |
| // forked from gcc/cp/constexpr.cc find_immediate_fndecl |
| |
| /* Find immediate function decls in *TP if any. */ |
| |
| static tree |
| find_immediate_fndecl (tree *tp, int * /*walk_subtrees*/, void * /*data*/) |
| { |
| if (TREE_CODE (*tp) == FUNCTION_DECL && DECL_IMMEDIATE_FUNCTION_P (*tp)) |
| return *tp; |
| if (TREE_CODE (*tp) == PTRMEM_CST |
| && TREE_CODE (PTRMEM_CST_MEMBER (*tp)) == FUNCTION_DECL |
| && DECL_IMMEDIATE_FUNCTION_P (PTRMEM_CST_MEMBER (*tp))) |
| return PTRMEM_CST_MEMBER (*tp); |
| return NULL_TREE; |
| } |
| |
| // forked in gcc/cp/constexpr.cc diag_array_subscript |
| |
| /* Under the control of CTX, issue a detailed diagnostic for |
| an out-of-bounds subscript INDEX into the expression ARRAY. */ |
| |
| static void |
| diag_array_subscript (location_t loc, const constexpr_ctx *ctx, tree array, |
| tree index) |
| { |
| if (!ctx->quiet) |
| { |
| tree arraytype = TREE_TYPE (array); |
| |
| /* Convert the unsigned array subscript to a signed integer to avoid |
| printing huge numbers for small negative values. */ |
| tree sidx = fold_convert (ssizetype, index); |
| STRIP_ANY_LOCATION_WRAPPER (array); |
| if (DECL_P (array)) |
| { |
| if (TYPE_DOMAIN (arraytype)) |
| error_at (loc, |
| "array subscript value %qE is outside the bounds " |
| "of array %qD of type %qT", |
| sidx, array, arraytype); |
| else |
| error_at (loc, |
| "nonzero array subscript %qE is used with array %qD of " |
| "type %qT with unknown bounds", |
| sidx, array, arraytype); |
| inform (DECL_SOURCE_LOCATION (array), "declared here"); |
| } |
| else if (TYPE_DOMAIN (arraytype)) |
| error_at (loc, |
| "array subscript value %qE is outside the bounds " |
| "of array type %qT", |
| sidx, arraytype); |
| else |
| error_at (loc, |
| "nonzero array subscript %qE is used with array of type %qT " |
| "with unknown bounds", |
| sidx, arraytype); |
| } |
| } |
| |
| // forked from gcc/cp/constexpr.cc get_array_or_vector_nelts |
| |
| /* Return the number of elements for TYPE (which is an ARRAY_TYPE or |
| a VECTOR_TYPE). */ |
| |
| static tree |
| get_array_or_vector_nelts (const constexpr_ctx *ctx, tree type, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| tree nelts; |
| if (TREE_CODE (type) == ARRAY_TYPE) |
| { |
| if (TYPE_DOMAIN (type)) |
| nelts = array_type_nelts_top (type); |
| else |
| nelts = size_zero_node; |
| } |
| else if (VECTOR_TYPE_P (type)) |
| nelts = size_int (TYPE_VECTOR_SUBPARTS (type)); |
| else |
| rust_unreachable (); |
| |
| /* For VLAs, the number of elements won't be an integer constant. */ |
| nelts |
| = eval_constant_expression (ctx, nelts, false, non_constant_p, overflow_p); |
| return nelts; |
| } |
| |
| // forked from gcc/cp/constexpr.cc eval_and_check_array_index |
| |
| /* Subroutine of cxx_eval_array_reference. T is an ARRAY_REF; evaluate the |
| subscript, diagnose any problems with it, and return the result. */ |
| |
| static tree |
| eval_and_check_array_index (const constexpr_ctx *ctx, tree t, |
| bool allow_one_past, bool *non_constant_p, |
| bool *overflow_p) |
| { |
| location_t loc = rs_expr_loc_or_input_loc (t); |
| tree ary = TREE_OPERAND (t, 0); |
| t = TREE_OPERAND (t, 1); |
| tree index = eval_constant_expression (ctx, t, allow_one_past, non_constant_p, |
| overflow_p); |
| VERIFY_CONSTANT (index); |
| |
| if (!tree_fits_shwi_p (index) || tree_int_cst_sgn (index) < 0) |
| { |
| diag_array_subscript (loc, ctx, ary, index); |
| *non_constant_p = true; |
| return t; |
| } |
| |
| tree nelts = get_array_or_vector_nelts (ctx, TREE_TYPE (ary), non_constant_p, |
| overflow_p); |
| VERIFY_CONSTANT (nelts); |
| if (allow_one_past ? !tree_int_cst_le (index, nelts) |
| : !tree_int_cst_lt (index, nelts)) |
| { |
| diag_array_subscript (loc, ctx, ary, index); |
| *non_constant_p = true; |
| return t; |
| } |
| |
| return index; |
| } |
| |
| // forked from gcc/cp/constexpr.cc extract_string_elt |
| |
| /* Extract element INDEX consisting of CHARS_PER_ELT chars from |
| STRING_CST STRING. */ |
| |
| static tree |
| extract_string_elt (tree string, unsigned chars_per_elt, unsigned index) |
| { |
| tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (string))); |
| tree r; |
| |
| if (chars_per_elt == 1) |
| r = build_int_cst (type, TREE_STRING_POINTER (string)[index]); |
| else |
| { |
| const unsigned char *ptr |
| = ((const unsigned char *) TREE_STRING_POINTER (string) |
| + index * chars_per_elt); |
| r = native_interpret_expr (type, ptr, chars_per_elt); |
| } |
| return r; |
| } |
| |
| /* Check whether the parameter and return types of FUN are valid for a |
| constexpr function, and complain if COMPLAIN. */ |
| |
| bool |
| is_valid_constexpr_fn (tree fun, bool complain) |
| { |
| bool ret = true; |
| |
| for (tree parm = FUNCTION_FIRST_USER_PARM (fun); parm != NULL_TREE; |
| parm = TREE_CHAIN (parm)) |
| if (!literal_type_p (TREE_TYPE (parm))) |
| { |
| ret = false; |
| if (complain) |
| { |
| // auto_diagnostic_group d; |
| // error ("invalid type for parameter %d of %<constexpr%> " |
| // "function %q+#D", |
| // DECL_PARM_INDEX (parm), fun); |
| location_t locus = DECL_SOURCE_LOCATION (fun); |
| rust_error_at ( |
| locus, "invalid type for parameter %d of %<constexpr%> function", |
| DECL_PARM_INDEX (parm)); |
| } |
| } |
| |
| return ret; |
| } |
| |
| void |
| explain_invalid_constexpr_fn (tree fun) |
| { |
| static hash_set<tree> *diagnosed; |
| // tree body; |
| |
| if (diagnosed == NULL) |
| diagnosed = new hash_set<tree>; |
| if (diagnosed->add (fun)) |
| /* Already explained. */ |
| return; |
| |
| iloc_sentinel ils = input_location; |
| // if (!lambda_static_thunk_p (fun)) |
| // { |
| // /* Diagnostics should completely ignore the static thunk, so leave |
| // input_location set to our caller's location. */ |
| // input_location = DECL_SOURCE_LOCATION (fun); |
| // inform (input_location, |
| // "%qD is not usable as a %<constexpr%> function because:", |
| // fun); |
| // } |
| |
| /* First check the declaration. */ |
| if (is_valid_constexpr_fn (fun, true)) |
| { |
| // /* Then if it's OK, the body. */ |
| // if (!DECL_DECLARED_CONSTEXPR_P (fun)) |
| // explain_implicit_non_constexpr (fun); |
| // else |
| // { |
| // if (constexpr_fundef *fd = retrieve_constexpr_fundef (fun)) |
| // body = fd->body; |
| // else |
| // body = DECL_SAVED_TREE (fun); |
| // body = massage_constexpr_body (fun, body); |
| // require_potential_rvalue_constant_expression (body); |
| // } |
| } |
| } |
| |
| /* BODY is a validated and massaged definition of a constexpr |
| function. Register it in the hash table. */ |
| |
| void |
| register_constexpr_fundef (const rust_constexpr_fundef &value) |
| { |
| /* Create the constexpr function table if necessary. */ |
| if (constexpr_fundef_table == NULL) |
| constexpr_fundef_table |
| = hash_table<rust_constexpr_fundef_hasher>::create_ggc (101); |
| |
| rust_constexpr_fundef **slot = constexpr_fundef_table->find_slot ( |
| const_cast<rust_constexpr_fundef *> (&value), INSERT); |
| |
| gcc_assert (*slot == NULL); |
| *slot = ggc_alloc<rust_constexpr_fundef> (); |
| **slot = value; |
| } |
| |
| /* We are processing the definition of the constexpr function FUN. |
| Check that its body fulfills the apropriate requirements and |
| enter it in the constexpr function definition table. */ |
| |
| void |
| maybe_save_constexpr_fundef (tree fun) |
| { |
| // FIXME |
| |
| rust_constexpr_fundef entry = {fun, NULL_TREE, NULL_TREE, NULL_TREE}; |
| bool clear_ctx = false; |
| if (DECL_RESULT (fun) && DECL_CONTEXT (DECL_RESULT (fun)) == NULL_TREE) |
| { |
| clear_ctx = true; |
| DECL_CONTEXT (DECL_RESULT (fun)) = fun; |
| } |
| tree saved_fn = current_function_decl; |
| current_function_decl = fun; |
| entry.body = copy_fn (entry.decl, entry.parms, entry.result); |
| current_function_decl = saved_fn; |
| if (clear_ctx) |
| DECL_CONTEXT (DECL_RESULT (entry.decl)) = NULL_TREE; |
| |
| register_constexpr_fundef (entry); |
| } |
| |
| /* Evaluate a STATEMENT_LIST for side-effects. Handles various jump |
| semantics, for switch, break, continue, and return. */ |
| |
| static tree |
| eval_statement_list (const constexpr_ctx *ctx, tree t, bool *non_constant_p, |
| bool *overflow_p, tree *jump_target) |
| { |
| tree local_target; |
| /* In a statement-expression we want to return the last value. |
| For empty statement expression return void_node. */ |
| tree r = void_node; |
| if (!jump_target) |
| { |
| local_target = NULL_TREE; |
| jump_target = &local_target; |
| } |
| for (tree stmt : tsi_range (t)) |
| { |
| /* We've found a continue, so skip everything until we reach |
| the label its jumping to. */ |
| if (continues (jump_target)) |
| { |
| if (label_matches (ctx, jump_target, stmt)) |
| /* Found it. */ |
| *jump_target = NULL_TREE; |
| else |
| continue; |
| } |
| if (TREE_CODE (stmt) == DEBUG_BEGIN_STMT) |
| continue; |
| r = eval_constant_expression (ctx, stmt, false, non_constant_p, |
| overflow_p, jump_target); |
| if (*non_constant_p) |
| break; |
| if (returns (jump_target) || breaks (jump_target)) |
| break; |
| } |
| if (*jump_target && jump_target == &local_target) |
| { |
| /* We aren't communicating the jump to our caller, so give up. We don't |
| need to support evaluation of jumps out of statement-exprs. */ |
| if (!ctx->quiet) |
| error_at (EXPR_LOCATION (r), "statement is not a constant expression"); |
| *non_constant_p = true; |
| } |
| return r; |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_conditional_expression |
| |
| /* Subroutine of cxx_eval_constant_expression. |
| Attempt to evaluate condition expressions. Dead branches are not |
| looked into. */ |
| |
| static tree |
| eval_conditional_expression (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p, |
| tree *jump_target) |
| { |
| tree val |
| = eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
| /*lval*/ false, non_constant_p, overflow_p); |
| VERIFY_CONSTANT (val); |
| if (TREE_CODE (t) == IF_STMT && IF_STMT_CONSTEVAL_P (t)) |
| { |
| /* Evaluate the condition as if it was |
| if (__builtin_is_constant_evaluated ()), i.e. defer it if not |
| ctx->manifestly_const_eval (as sometimes we try to constant evaluate |
| without manifestly_const_eval even expressions or parts thereof which |
| will later be manifestly const_eval evaluated), otherwise fold it to |
| true. */ |
| if (ctx->manifestly_const_eval) |
| val = boolean_true_node; |
| else |
| { |
| *non_constant_p = true; |
| return t; |
| } |
| } |
| /* Don't VERIFY_CONSTANT the other operands. */ |
| if (integer_zerop (val)) |
| val = TREE_OPERAND (t, 2); |
| else |
| val = TREE_OPERAND (t, 1); |
| if (/*TREE_CODE (t) == IF_STMT && */ !val) |
| val = void_node; |
| return eval_constant_expression (ctx, val, lval, non_constant_p, overflow_p, |
| jump_target); |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_bit_field_ref |
| |
| /* Subroutine of cxx_eval_constant_expression. |
| Attempt to reduce a field access of a value of class type that is |
| expressed as a BIT_FIELD_REF. */ |
| |
| static tree |
| eval_bit_field_ref (const constexpr_ctx *ctx, tree t, bool lval, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| tree orig_whole = TREE_OPERAND (t, 0); |
| tree retval, fldval, utype, mask; |
| bool fld_seen = false; |
| HOST_WIDE_INT istart, isize; |
| tree whole = eval_constant_expression (ctx, orig_whole, lval, non_constant_p, |
| overflow_p); |
| tree start, field, value; |
| unsigned HOST_WIDE_INT i; |
| |
| if (whole == orig_whole) |
| return t; |
| /* Don't VERIFY_CONSTANT here; we only want to check that we got a |
| CONSTRUCTOR. */ |
| if (!*non_constant_p && TREE_CODE (whole) != VECTOR_CST |
| && TREE_CODE (whole) != CONSTRUCTOR) |
| { |
| if (!ctx->quiet) |
| error ("%qE is not a constant expression", orig_whole); |
| *non_constant_p = true; |
| } |
| if (*non_constant_p) |
| return t; |
| |
| if (TREE_CODE (whole) == VECTOR_CST) |
| return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole, |
| TREE_OPERAND (t, 1), TREE_OPERAND (t, 2)); |
| |
| start = TREE_OPERAND (t, 2); |
| istart = tree_to_shwi (start); |
| isize = tree_to_shwi (TREE_OPERAND (t, 1)); |
| utype = TREE_TYPE (t); |
| if (!TYPE_UNSIGNED (utype)) |
| utype = build_nonstandard_integer_type (TYPE_PRECISION (utype), 1); |
| retval = build_int_cst (utype, 0); |
| FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) |
| { |
| tree bitpos = bit_position (field); |
| STRIP_ANY_LOCATION_WRAPPER (value); |
| if (bitpos == start && DECL_SIZE (field) == TREE_OPERAND (t, 1)) |
| return value; |
| if (TREE_CODE (TREE_TYPE (field)) == INTEGER_TYPE |
| && TREE_CODE (value) == INTEGER_CST && tree_fits_shwi_p (bitpos) |
| && tree_fits_shwi_p (DECL_SIZE (field))) |
| { |
| HOST_WIDE_INT bit = tree_to_shwi (bitpos); |
| HOST_WIDE_INT sz = tree_to_shwi (DECL_SIZE (field)); |
| HOST_WIDE_INT shift; |
| if (bit >= istart && bit + sz <= istart + isize) |
| { |
| fldval = fold_convert (utype, value); |
| mask = build_int_cst_type (utype, -1); |
| mask = fold_build2 (LSHIFT_EXPR, utype, mask, |
| size_int (TYPE_PRECISION (utype) - sz)); |
| mask = fold_build2 (RSHIFT_EXPR, utype, mask, |
| size_int (TYPE_PRECISION (utype) - sz)); |
| fldval = fold_build2 (BIT_AND_EXPR, utype, fldval, mask); |
| shift = bit - istart; |
| if (BYTES_BIG_ENDIAN) |
| shift = TYPE_PRECISION (utype) - shift - sz; |
| fldval |
| = fold_build2 (LSHIFT_EXPR, utype, fldval, size_int (shift)); |
| retval = fold_build2 (BIT_IOR_EXPR, utype, retval, fldval); |
| fld_seen = true; |
| } |
| } |
| } |
| if (fld_seen) |
| return fold_convert (TREE_TYPE (t), retval); |
| rust_unreachable (); |
| return error_mark_node; |
| } |
| |
| // forked from gcc/cp/constexpr.cc returns |
| |
| /* Predicates for the meaning of *jump_target. */ |
| |
| static bool |
| returns (tree *jump_target) |
| { |
| return *jump_target |
| && (TREE_CODE (*jump_target) == RETURN_EXPR |
| || (TREE_CODE (*jump_target) == LABEL_DECL |
| && LABEL_DECL_CDTOR (*jump_target))); |
| } |
| |
| // forked from gcc/cp/constexpr.cc breaks |
| |
| static bool |
| breaks (tree *jump_target) |
| { |
| return *jump_target |
| && ((TREE_CODE (*jump_target) == LABEL_DECL |
| && LABEL_DECL_BREAK (*jump_target)) |
| || TREE_CODE (*jump_target) == BREAK_STMT |
| || TREE_CODE (*jump_target) == EXIT_EXPR); |
| } |
| |
| // forked from gcc/cp/constexpr.cc continues |
| |
| static bool |
| continues (tree *jump_target) |
| { |
| return *jump_target |
| && ((TREE_CODE (*jump_target) == LABEL_DECL |
| && LABEL_DECL_CONTINUE (*jump_target)) |
| || TREE_CODE (*jump_target) == CONTINUE_STMT); |
| } |
| |
| // forked from gcc/cp/constexpr.cc switches |
| |
| static bool |
| switches (tree *jump_target) |
| { |
| return *jump_target && TREE_CODE (*jump_target) == INTEGER_CST; |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_loop_expr |
| |
| /* Evaluate a LOOP_EXPR for side-effects. Handles break and return |
| semantics; continue semantics are covered by cxx_eval_statement_list. */ |
| |
| static tree |
| eval_loop_expr (const constexpr_ctx *ctx, tree t, bool *non_constant_p, |
| bool *overflow_p, tree *jump_target) |
| { |
| constexpr_ctx new_ctx = *ctx; |
| tree local_target; |
| if (!jump_target) |
| { |
| local_target = NULL_TREE; |
| jump_target = &local_target; |
| } |
| |
| tree body, cond = NULL_TREE, expr = NULL_TREE; |
| int count = 0; |
| switch (TREE_CODE (t)) |
| { |
| case LOOP_EXPR: |
| body = LOOP_EXPR_BODY (t); |
| break; |
| case WHILE_STMT: |
| body = WHILE_BODY (t); |
| cond = WHILE_COND (t); |
| count = -1; |
| break; |
| case FOR_STMT: |
| if (FOR_INIT_STMT (t)) |
| eval_constant_expression (ctx, FOR_INIT_STMT (t), /*lval*/ false, |
| non_constant_p, overflow_p, jump_target); |
| if (*non_constant_p) |
| return NULL_TREE; |
| body = FOR_BODY (t); |
| cond = FOR_COND (t); |
| expr = FOR_EXPR (t); |
| count = -1; |
| break; |
| default: |
| rust_unreachable (); |
| } |
| auto_vec<tree, 10> save_exprs; |
| new_ctx.save_exprs = &save_exprs; |
| do |
| { |
| if (count != -1) |
| { |
| if (body) |
| eval_constant_expression (&new_ctx, body, /*lval*/ false, |
| non_constant_p, overflow_p, jump_target); |
| if (breaks (jump_target)) |
| { |
| *jump_target = NULL_TREE; |
| break; |
| } |
| |
| if (TREE_CODE (t) != LOOP_EXPR && continues (jump_target)) |
| *jump_target = NULL_TREE; |
| |
| if (expr) |
| eval_constant_expression (&new_ctx, expr, /*lval*/ false, |
| non_constant_p, overflow_p, jump_target); |
| } |
| |
| if (cond) |
| { |
| tree res = eval_constant_expression (&new_ctx, cond, /*lval*/ false, |
| non_constant_p, overflow_p, |
| jump_target); |
| if (res) |
| { |
| if (verify_constant (res, ctx->quiet, non_constant_p, overflow_p)) |
| break; |
| if (integer_zerop (res)) |
| break; |
| } |
| else |
| gcc_assert (*jump_target); |
| } |
| |
| /* Forget saved values of SAVE_EXPRs and TARGET_EXPRs. */ |
| for (tree save_expr : save_exprs) |
| ctx->global->values.remove (save_expr); |
| save_exprs.truncate (0); |
| |
| if (++count >= constexpr_loop_limit) |
| { |
| if (!ctx->quiet) |
| error_at (rs_expr_loc_or_input_loc (t), |
| "%<constexpr%> loop iteration count exceeds limit of %d " |
| "(use %<-fconstexpr-loop-limit=%> to increase the limit)", |
| constexpr_loop_limit); |
| *non_constant_p = true; |
| break; |
| } |
| } |
| while (!returns (jump_target) && !breaks (jump_target) |
| && !continues (jump_target) && (!switches (jump_target) || count == 0) |
| && !*non_constant_p); |
| |
| /* Forget saved values of SAVE_EXPRs and TARGET_EXPRs. */ |
| for (tree save_expr : save_exprs) |
| ctx->global->values.remove (save_expr); |
| |
| return NULL_TREE; |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_switch_expr |
| |
| /* Evaluate a SWITCH_EXPR for side-effects. Handles switch and break jump |
| semantics. */ |
| |
| static tree |
| eval_switch_expr (const constexpr_ctx *ctx, tree t, bool *non_constant_p, |
| bool *overflow_p, tree *jump_target) |
| { |
| tree cond |
| = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_COND (t) : SWITCH_COND (t); |
| cond |
| = eval_constant_expression (ctx, cond, false, non_constant_p, overflow_p); |
| VERIFY_CONSTANT (cond); |
| *jump_target = cond; |
| |
| tree body |
| = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_BODY (t) : SWITCH_BODY (t); |
| constexpr_ctx new_ctx = *ctx; |
| constexpr_switch_state css = css_default_not_seen; |
| new_ctx.css_state = &css; |
| eval_constant_expression (&new_ctx, body, false, non_constant_p, overflow_p, |
| jump_target); |
| if (switches (jump_target) && css == css_default_seen) |
| { |
| /* If the SWITCH_EXPR body has default: label, process it once again, |
| this time instructing label_matches to return true for default: |
| label on switches (jump_target). */ |
| css = css_default_processing; |
| eval_constant_expression (&new_ctx, body, false, non_constant_p, |
| overflow_p, jump_target); |
| } |
| if (breaks (jump_target) || switches (jump_target)) |
| *jump_target = NULL_TREE; |
| return NULL_TREE; |
| } |
| |
| // forked from gcc/cp/constexpr.cc eval_unary_expression |
| |
| /* Subroutine of cxx_eval_constant_expression. |
| Attempt to reduce the unary expression tree T to a compile time value. |
| If successful, return the value. Otherwise issue a diagnostic |
| and return error_mark_node. */ |
| |
| static tree |
| eval_unary_expression (const constexpr_ctx *ctx, tree t, bool /*lval*/, |
| bool *non_constant_p, bool *overflow_p) |
| { |
| tree r; |
| tree orig_arg = TREE_OPERAND (t, 0); |
| tree arg = eval_constant_expression (ctx, orig_arg, /*lval*/ false, |
| non_constant_p, overflow_p); |
| VERIFY_CONSTANT (arg); |
| location_t loc = EXPR_LOCATION (t); |
| enum tree_code code = TREE_CODE (t); |
| tree type = TREE_TYPE (t); |
| r = fold_unary_loc (loc, code, type, arg); |
| if (r == NULL_TREE) |
| { |
| if (arg == orig_arg) |
| r = t; |
| else |
| r = build1_loc (loc, code, type, arg); |
| } |
| VERIFY_CONSTANT (r); |
| return r; |
| } |
| |
| // forked from gcc/cp/constexpr.cc cxx_eval_outermost_constant_expr |
| |
| /* ALLOW_NON_CONSTANT is false if T is required to be a constant expression. |
| STRICT has the same sense as for constant_value_1: true if we only allow |
| conforming C++ constant expressions, or false if we want a constant value |
| even if it doesn't conform. |
| MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
| per P0595 even when ALLOW_NON_CONSTANT is true. |
| CONSTEXPR_DTOR is true when evaluating the dtor of a constexpr variable. |
| OBJECT must be non-NULL in that case. */ |
| |
| static tree |
| cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, |
| bool strict = true, |
| bool manifestly_const_eval = false, |
| bool constexpr_dtor = false, |
| tree object = NULL_TREE) |
| { |
| auto_timevar time (TV_CONSTEXPR); |
| |
| bool non_constant_p = false; |
| bool overflow_p = false; |
| |
| if (BRACE_ENCLOSED_INITIALIZER_P (t)) |
| { |
| gcc_checking_assert (allow_non_constant); |
| return t; |
| } |
| |
| constexpr_global_ctx global_ctx; |
| constexpr_ctx ctx |
| = {&global_ctx, NULL, |
| NULL, NULL, |
| NULL, NULL, |
| NULL, allow_non_constant, |
| strict, manifestly_const_eval || !allow_non_constant}; |
| |
| /* Turn off -frounding-math for manifestly constant evaluation. */ |
| warning_sentinel rm (flag_rounding_math, ctx.manifestly_const_eval); |
| tree type = initialized_type (t); |
| tree r = t; |
| bool is_consteval = false; |
| if (VOID_TYPE_P (type)) |
| { |
| if (constexpr_dtor) |
| /* Used for destructors of array elements. */ |
| type = TREE_TYPE (object); |
| else |
| { |
| if (TREE_CODE (t) != CALL_EXPR) |
| return t; |
| /* Calls to immediate functions returning void need to be |
| evaluated. */ |
| tree fndecl = rs_get_callee_fndecl_nofold (t); |
| if (fndecl == NULL_TREE || !DECL_IMMEDIATE_FUNCTION_P (fndecl)) |
| return t; |
| else |
| is_consteval = true; |
| } |
| } |
| else if ((TREE_CODE (t) == CALL_EXPR || TREE_CODE (t) == TARGET_EXPR)) |
| { |
| /* For non-concept checks, determine if it is consteval. */ |
| tree x = t; |
| if (TREE_CODE (x) == TARGET_EXPR) |
| x = TARGET_EXPR_INITIAL (x); |
| tree fndecl = rs_get_callee_fndecl_nofold (x); |
| if (fndecl && DECL_IMMEDIATE_FUNCTION_P (fndecl)) |
| is_consteval = true; |
| } |
| if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) |
| { |
| /* In C++14 an NSDMI can participate in aggregate initialization, |
| and can refer to the address of the object being initialized, so |
| we need to pass in the relevant VAR_DECL if we want to do the |
| evaluation in a single pass. The evaluation will dynamically |
| update ctx.values for the VAR_DECL. We use the same strategy |
| for C++11 constexpr constructors that refer to the object being |
| initialized. */ |
| if (constexpr_dtor) |
| { |
| gcc_assert (object && VAR_P (object)); |
| gcc_assert (DECL_DECLARED_CONSTEXPR_P (object)); |
| gcc_assert (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object)); |
| if (error_operand_p (DECL_INITIAL (object))) |
| return t; |
| ctx.ctor = unshare_expr (DECL_INITIAL (object)); |
| TREE_READONLY (ctx.ctor) = false; |
| /* Temporarily force decl_really_constant_value to return false |
| for it, we want to use ctx.ctor for the current value instead. */ |
| DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object) = false; |
| } |
| else |
| { |
| ctx.ctor = build_constructor (type, NULL); |
| CONSTRUCTOR_NO_CLEARING (ctx.ctor) = true; |
| } |
| if (!object) |
| { |
| if (TREE_CODE (t) == TARGET_EXPR) |
| object = TARGET_EXPR_SLOT (t); |
| } |
| ctx.object = object; |
| if (object) |
| gcc_assert ( |
| same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (object))); |
| if (object && DECL_P (object)) |
| global_ctx.values.put (object, ctx.ctor); |
| if (TREE_CODE (r) == TARGET_EXPR) |
| /* Avoid creating another CONSTRUCTOR when we expand the |
| TARGET_EXPR. */ |
| r = TARGET_EXPR_INITIAL (r); |
| } |
| |
| auto_vec<tree, 16> cleanups; |
| global_ctx.cleanups = &cleanups; |
| |
| if (manifestly_const_eval) |
| instantiate_constexpr_fns (r); |
| r = eval_constant_expression (&ctx, r, false, &non_constant_p, &overflow_p); |
| |
| if (!constexpr_dtor) |
| verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p); |
| else |
| DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object) = true; |
| |
| unsigned int i; |
| tree cleanup; |
| /* Evaluate the cleanups. */ |
| FOR_EACH_VEC_ELT_REVERSE (cleanups, i, cleanup) |
| eval_constant_expression (&ctx, cleanup, false, &non_constant_p, |
| &overflow_p); |
| |
| /* Mutable logic is a bit tricky: we want to allow initialization of |
| constexpr variables with mutable members, but we can't copy those |
| members to another constexpr variable. */ |
| if (TREE_CODE (r) == CONSTRUCTOR && CONSTRUCTOR_MUTABLE_POISON (r)) |
| { |
| if (!allow_non_constant) |
| error ("%qE is not a constant expression because it refers to " |
| "mutable subobjects of %qT", |
| t, type); |
| non_constant_p = true; |
| } |
| |
| if (TREE_CODE (r) == CONSTRUCTOR && CONSTRUCTOR_NO_CLEARING (r)) |
| { |
| if (!allow_non_constant) |
| error ("%qE is not a constant expression because it refers to " |
| "an incompletely initialized variable", |
| t); |
| TREE_CONSTANT (r) = false; |
| non_constant_p = true; |
| } |
| |
| if (!global_ctx.heap_vars.is_empty ()) |
| { |
| tree heap_var |
| = rs_walk_tree_without_duplicates (&r, find_heap_var_refs, NULL); |
| unsigned int i; |
| if (heap_var) |
| { |
| if (!allow_non_constant && !non_constant_p) |
| error_at (DECL_SOURCE_LOCATION (heap_var), |
| "%qE is not a constant expression because it refers to " |
| "a result of %<operator new%>", |
| t); |
| r = t; |
| non_constant_p = true; |
| } |
| FOR_EACH_VEC_ELT (global_ctx.heap_vars, i, heap_var) |
| { |
| if (DECL_NAME (heap_var) != heap_deleted_identifier) |
| { |
| if (!allow_non_constant && !non_constant_p) |
| error_at (DECL_SOURCE_LOCATION (heap_var), |
| "%qE is not a constant expression because allocated " |
| "storage has not been deallocated", |
| t); |
| r = t; |
| non_constant_p = true; |
| } |
| varpool_node::get (heap_var)->remove (); |
| } |
| } |
| |
| /* Check that immediate invocation does not return an expression referencing |
| any immediate function decls. */ |
| if (is_consteval || in_immediate_context ()) |
| if (tree immediate_fndecl |
| = rs_walk_tree_without_duplicates (&r, find_immediate_fndecl, NULL)) |
| { |
| if (!allow_non_constant && !non_constant_p) |
| error_at (rs_expr_loc_or_input_loc (t), |
| "immediate evaluation returns address of immediate " |
| "function %qD", |
| immediate_fndecl); |
| r = t; |
| non_constant_p = true; |
| } |
| |
| if (non_constant_p) |
| /* If we saw something bad, go back to our argument. The wrapping below is |
| only for the cases of TREE_CONSTANT argument or overflow. */ |
| r = t; |
| |
| if (!non_constant_p && overflow_p) |
| non_constant_p = true; |
| |
| /* Unshare the result. */ |
| bool should_unshare = true; |
| if (r == t || (TREE_CODE (t) == TARGET_EXPR && TARGET_EXPR_INITIAL (t) == r)) |
| should_unshare = false; |
| |
| if (non_constant_p && !allow_non_constant) |
| return error_mark_node; |
| else if (constexpr_dtor) |
| return r; |
| else if (non_constant_p && TREE_CONSTANT (r)) |
| { |
| /* This isn't actually constant, so unset TREE_CONSTANT. |
| Don't clear TREE_CONSTANT on ADDR_EXPR, as the middle-end requires |
| it to be set if it is invariant address, even when it is not |
| a valid C++ constant expression. Wrap it with a NOP_EXPR |
| instead. */ |
| if (EXPR_P (r) && TREE_CODE (r) != ADDR_EXPR) |
| r = copy_node (r); |
| else if (TREE_CODE (r) == CONSTRUCTOR) |
| r = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (r), r); |
| else |
| r = build_nop (TREE_TYPE (r), r); |
| TREE_CONSTANT (r) = false; |
| } |
| else if (non_constant_p) |
| return t; |
| |
| if (should_unshare) |
| r = unshare_expr (r); |
| |
| if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r))) |
| { |
| r = adjust_temp_type (type, r); |
| if (TREE_CODE (t) == TARGET_EXPR && TARGET_EXPR_INITIAL (t) == r) |
| return t; |
| } |
| |
| /* Remember the original location if that wouldn't need a wrapper. */ |
| if (location_t loc = EXPR_LOCATION (t)) |
| protected_set_expr_location (r, loc); |
| |
| return r; |
| } |
| |
| /* Like is_constant_expression, but allow const variables that are not allowed |
| under constexpr rules. */ |
| |
| bool |
| is_static_init_expression (tree t) |
| { |
| return potential_constant_expression_1 (t, false, false, true, tf_none); |
| } |
| |
| /* Like potential_constant_expression, but don't consider possible constexpr |
| substitution of the current function. That is, PARM_DECL qualifies under |
| potential_constant_expression, but not here. |
| |
| This is basically what you can check when any actual constant values might |
| be value-dependent. */ |
| |
| bool |
| is_constant_expression (tree t) |
| { |
| return potential_constant_expression_1 (t, false, true, true, tf_none); |
| } |
| |
| /* Returns true if T is a potential static initializer expression that is not |
| instantiation-dependent. */ |
| |
| bool |
| is_nondependent_static_init_expression (tree t) |
| { |
| return (!type_unknown_p (t) && is_static_init_expression (t)); |
| } |
| |
| /* Like maybe_constant_value, but returns a CONSTRUCTOR directly, rather |
| than wrapped in a TARGET_EXPR. |
| ALLOW_NON_CONSTANT is false if T is required to be a constant expression. |
| MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
| per P0595 even when ALLOW_NON_CONSTANT is true. */ |
| |
| static tree |
| maybe_constant_init_1 (tree t, tree decl, bool allow_non_constant, |
| bool manifestly_const_eval) |
| { |
| if (!t) |
| return t; |
| if (TREE_CODE (t) == EXPR_STMT) |
| t = TREE_OPERAND (t, 0); |
| if (TREE_CODE (t) == CONVERT_EXPR && VOID_TYPE_P (TREE_TYPE (t))) |
| t = TREE_OPERAND (t, 0); |
| if (TREE_CODE (t) == INIT_EXPR) |
| t = TREE_OPERAND (t, 1); |
| if (TREE_CODE (t) == TARGET_EXPR) |
| t = TARGET_EXPR_INITIAL (t); |
| if (!is_nondependent_static_init_expression (t)) |
| /* Don't try to evaluate it. */; |
| else if (CONSTANT_CLASS_P (t) && allow_non_constant) |
| /* No evaluation needed. */; |
| else |
| t = cxx_eval_outermost_constant_expr (t, allow_non_constant, |
| /*strict*/ false, |
| manifestly_const_eval, false, decl); |
| if (TREE_CODE (t) == TARGET_EXPR) |
| { |
| tree init = TARGET_EXPR_INITIAL (t); |
| if (TREE_CODE (init) == CONSTRUCTOR) |
| t = init; |
| } |
| return t; |
| } |
| |
| /* Wrapper for maybe_constant_init_1 which permits non constants. */ |
| |
| tree |
| maybe_constant_init (tree t, tree decl, bool manifestly_const_eval) |
| { |
| return maybe_constant_init_1 (t, decl, true, manifestly_const_eval); |
| } |
| |
| /* Returns true if T is a potential constant expression that is not |
| instantiation-dependent, and therefore a candidate for constant folding even |
| in a template. */ |
| |
| bool |
| is_nondependent_constant_expression (tree t) |
| { |
| return (!type_unknown_p (t) && is_constant_expression (t) |
| && !instantiation_dependent_expression_p (t)); |
| } |
| |
| // forked from gcc/cp/parser.cc cp_unevaluated_operand |
| |
| /* Nonzero if we are parsing an unevaluated operand: an operand to |
| sizeof, typeof, or alignof. */ |
| int cp_unevaluated_operand; |
| |
| // forked from gcc/cp/constexpr.cc cv_cache |
| |
| /* If T is a constant expression, returns its reduced value. |
| Otherwise, if T does not have TREE_CONSTANT set, returns T. |
| Otherwise, returns a version of T without TREE_CONSTANT. |
| MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated |
| as per P0595. */ |
| |
| static GTY ((deletable)) hash_map<tree, tree> *cv_cache; |
| |
| // forked from gcc/cp/constexpr.cc maybe_constant_value |
| |
| tree |
| maybe_constant_value (tree t, tree decl, bool manifestly_const_eval) |
| { |
| tree r; |
| |
| if (!is_nondependent_constant_expression (t)) |
| { |
| if (TREE_OVERFLOW_P (t)) |
| { |
| t = build_nop (TREE_TYPE (t), t); |
| TREE_CONSTANT (t) = false; |
| } |
| return t; |
| } |
| else if (CONSTANT_CLASS_P (t)) |
| /* No caching or evaluation needed. */ |
| return t; |
| |
| if (manifestly_const_eval) |
| return cxx_eval_outermost_constant_expr (t, true, true, true, false, decl); |
| |
| if (cv_cache == NULL) |
| cv_cache = hash_map<tree, tree>::create_ggc (101); |
| if (tree *cached = cv_cache->get (t)) |
| { |
| r = *cached; |
| if (r != t) |
| { |
| // Faisal: commenting this out as not sure if it's needed and it's |
| // huge r = break_out_target_exprs (r, /*clear_loc*/true); |
| protected_set_expr_location (r, EXPR_LOCATION (t)); |
| } |
| return r; |
| } |
| |
| /* Don't evaluate an unevaluated operand. */ |
| if (cp_unevaluated_operand) |
| return t; |
| |
| uid_sensitive_constexpr_evaluation_checker c; |
| r = cxx_eval_outermost_constant_expr (t, true, true, false, false, decl); |
| gcc_checking_assert ( |
| r == t || CONVERT_EXPR_P (t) || TREE_CODE (t) == VIEW_CONVERT_EXPR |
| || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) || !rs_tree_equal (r, t)); |
| if (!c.evaluation_restricted_p ()) |
| cv_cache->put (t, r); |
| return r; |
| } |
| |
| // forked from gcc/cp/constexpr.cc |
| |
| bool |
| potential_constant_expression (tree t) |
| { |
| return potential_constant_expression_1 (t, false, true, false, tf_none); |
| } |
| |
| /* Data structure for passing data from potential_constant_expression_1 |
| to check_for_return_continue via cp_walk_tree. */ |
| struct check_for_return_continue_data |
| { |
| hash_set<tree> *pset; |
| tree continue_stmt; |
| tree break_stmt; |
| }; |
| |
| /* Helper function for potential_constant_expression_1 SWITCH_STMT handling, |
| called through cp_walk_tree. Return the first RETURN_EXPR found, or note |
| the first CONTINUE_STMT and/or BREAK_STMT if RETURN_EXPR is not found. */ |
| static tree |
| check_for_return_continue (tree *tp, int *walk_subtrees, void *data) |
| { |
| tree t = *tp, s, b; |
| check_for_return_continue_data *d = (check_for_return_continue_data *) data; |
| switch (TREE_CODE (t)) |
| { |
| case RETURN_EXPR: |
| return t; |
| |
| case CONTINUE_STMT: |
| if (d->continue_stmt == NULL_TREE) |
| d->continue_stmt = t; |
| break; |
| |
| case BREAK_STMT: |
| if (d->break_stmt == NULL_TREE) |
| d->break_stmt = t; |
| break; |
| |
| #define RECUR(x) \ |
| if (tree r = rs_walk_tree (&x, check_for_return_continue, data, d->pset)) \ |
| return r |
| |
| /* For loops, walk subtrees manually, so that continue stmts found |
| inside of the bodies of the loops are ignored. */ |
| |
| case WHILE_STMT: |
| *walk_subtrees = 0; |
| RECUR (WHILE_COND (t)); |
| s = d->continue_stmt; |
| b = d->break_stmt; |
| RECUR (WHILE_BODY (t)); |
| d->continue_stmt = s; |
| d->break_stmt = b; |
| break; |
| |
| case FOR_STMT: |
| *walk_subtrees = 0; |
| RECUR (FOR_INIT_STMT (t)); |
| RECUR (FOR_COND (t)); |
| RECUR (FOR_EXPR (t)); |
| s = d->continue_stmt; |
| b = d->break_stmt; |
| RECUR (FOR_BODY (t)); |
| d->continue_stmt = s; |
| d->break_stmt = b; |
| break; |
| |
| case RANGE_FOR_STMT: |
| *walk_subtrees = 0; |
| RECUR (RANGE_FOR_EXPR (t)); |
| s = d->continue_stmt; |
| b = d->break_stmt; |
| RECUR (RANGE_FOR_BODY (t)); |
| d->continue_stmt = s; |
| d->break_stmt = b; |
| break; |
| |
| case SWITCH_STMT: |
| *walk_subtrees = 0; |
| RECUR (SWITCH_STMT_COND (t)); |
| b = d->break_stmt; |
| RECUR (SWITCH_STMT_BODY (t)); |
| d->break_stmt = b; |
| break; |
| #undef RECUR |
| |
| case STATEMENT_LIST: |
| case CONSTRUCTOR: |
| break; |
| |
| default: |
| if (!EXPR_P (t)) |
| *walk_subtrees = 0; |
| break; |
| } |
| |
| return NULL_TREE; |
| } |
| |
| /* Returns the namespace that contains DECL, whether directly or |
| indirectly. */ |
| |
| tree |
| decl_namespace_context (tree decl) |
| { |
| while (1) |
| { |
| if (TREE_CODE (decl) == NAMESPACE_DECL) |
| return decl; |
| else if (TYPE_P (decl)) |
| decl = CP_DECL_CONTEXT (TYPE_MAIN_DECL (decl)); |
| else |
| decl = CP_DECL_CONTEXT (decl); |
| } |
| } |
| |
| /* Returns true if DECL is in the std namespace. */ |
| |
| bool |
| decl_in_std_namespace_p (tree decl) |
| { |
| while (decl) |
| { |
| decl = decl_namespace_context (decl); |
| if (DECL_NAMESPACE_STD_P (decl)) |
| return true; |
| /* Allow inline namespaces inside of std namespace, e.g. with |
| --enable-symvers=gnu-versioned-namespace std::forward would be |
| actually std::_8::forward. */ |
| if (!DECL_NAMESPACE_INLINE_P (decl)) |
| return false; |
| decl = CP_DECL_CONTEXT (decl); |
| } |
| return false; |
| } |
| |
| /* Return true if FNDECL is std::construct_at. */ |
| |
| static inline bool |
| is_std_construct_at (tree fndecl) |
| { |
| if (!decl_in_std_namespace_p (fndecl)) |
| return false; |
| |
| tree name = DECL_NAME (fndecl); |
| return name && id_equal (name, "construct_at"); |
| } |
| |
| /* Return true if FNDECL is __dynamic_cast. */ |
| |
| static inline bool |
| cxx_dynamic_cast_fn_p (tree fndecl) |
| { |
| return (id_equal (DECL_NAME (fndecl), "__dynamic_cast") |
| && CP_DECL_CONTEXT (fndecl) == global_namespace); |
| } |
| |
| /* Return true if FNDECL is std::allocator<T>::{,de}allocate. */ |
| |
| static inline bool |
| is_std_allocator_allocate (tree fndecl) |
| { |
| tree name = DECL_NAME (fndecl); |
| if (name == NULL_TREE |
| || !(id_equal (name, "allocate") || id_equal (name, "deallocate"))) |
| return false; |
| |
| tree ctx = DECL_CONTEXT (fndecl); |
| if (ctx == NULL_TREE || !CLASS_TYPE_P (ctx) || !TYPE_MAIN_DECL (ctx)) |
| return false; |
| |
| tree decl = TYPE_MAIN_DECL (ctx); |
| name = DECL_NAME (decl); |
| if (name == NULL_TREE || !id_equal (name, "allocator")) |
| return false; |
| |
| return decl_in_std_namespace_p (decl); |
| } |
| |
| /* Overload for the above taking rust_constexpr_call*. */ |
| |
| static inline bool |
| is_std_allocator_allocate (const rust_constexpr_call *call) |
| { |
| return (call && call->fundef |
| && is_std_allocator_allocate (call->fundef->decl)); |
| } |
| |
| /* Return true if T denotes a potentially constant expression. Issue |
| diagnostic as appropriate under control of FLAGS. If WANT_RVAL is true, |
| an lvalue-rvalue conversion is implied. If NOW is true, we want to |
| consider the expression in the current context, independent of constexpr |
| substitution. |
| |
| C++0x [expr.const] used to say |
| |
| 6 An expression is a potential constant expression if it is |
| a constant expression where all occurrences of function |
| parameters are replaced by arbitrary constant expressions |
| of the appropriate type. |
| |
| 2 A conditional expression is a constant expression unless it |
| involves one of the following as a potentially evaluated |
| subexpression (3.2), but subexpressions of logical AND (5.14), |
| logical OR (5.15), and conditional (5.16) operations that are |
| not evaluated are not considered. */ |
| |
| static bool |
| potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, |
| tsubst_flags_t flags, tree *jump_target) |
| { |
| #define RECUR(T, RV) \ |
| potential_constant_expression_1 ((T), (RV), strict, now, flags, jump_target) |
| |
| enum |
| { |
| any = false, |
| rval = true |
| }; |
| int i; |
| tree tmp; |
| |
| if (t == error_mark_node) |
| return false; |
| if (t == NULL_TREE) |
| return true; |
| location_t loc = rs_expr_loc_or_input_loc (t); |
| |
| if (*jump_target) |
| /* If we are jumping, ignore everything. This is simpler than the |
| cxx_eval_constant_expression handling because we only need to be |
| conservatively correct, and we don't necessarily have a constant value |
| available, so we don't bother with switch tracking. */ |
| return true; |
| |
| if (TREE_THIS_VOLATILE (t) && want_rval) |
| { |
| if (flags & tf_error) |
| error_at (loc, |
| "lvalue-to-rvalue conversion of a volatile lvalue " |
| "%qE with type %qT", |
| t, TREE_TYPE (t)); |
| return false; |
| } |
| if (CONSTANT_CLASS_P (t)) |
| return true; |
| if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED) |
| && TREE_TYPE (t) == error_mark_node) |
| return false; |
| |
| switch (TREE_CODE (t)) |
| { |
| case FUNCTION_DECL: |
| case OVERLOAD: |
| case LABEL_DECL: |
| case CASE_LABEL_EXPR: |
| case PREDICT_EXPR: |
| case CONST_DECL: |
| case IDENTIFIER_NODE: |
| /* We can see a FIELD_DECL in a pointer-to-member expression. */ |
| case FIELD_DECL: |
| case RESULT_DECL: |
| case PLACEHOLDER_EXPR: |
| case STATIC_ASSERT: |
| return true; |
| |
| case RETURN_EXPR: |
| if (!RECUR (TREE_OPERAND (t, 0), any)) |
| return false; |
| /* FALLTHROUGH */ |
| |
| case BREAK_STMT: |
| case CONTINUE_STMT: |
| *jump_target = t; |
| return true; |
| |
| case PARM_DECL: |
| if (now && want_rval) |
| { |
| tree type = TREE_TYPE (t); |
| if (is_really_empty_class (type, /*ignore_vptr*/ false)) |
| /* An empty class has no data to read. */ |
| return true; |
| if (flags & tf_error) |
| error ("%qE is not a constant expression", t); |
| return false; |
| } |
| return true; |
| |
| case CALL_EXPR: |
| /* -- an invocation of a function other than a constexpr function |
| or a constexpr constructor. */ |
| { |
| tree fun = get_function_named_in_call (t); |
| const int nargs = call_expr_nargs (t); |
| i = 0; |
| |
| if (fun == NULL_TREE) |
| { |
| /* Reset to allow the function to continue past the end |
| of the block below. Otherwise return early. */ |
| bool bail = true; |
| |
| if (TREE_CODE (t) == CALL_EXPR && CALL_EXPR_FN (t) == NULL_TREE) |
| switch (CALL_EXPR_IFN (t)) |
| { |
| /* These should be ignored, they are optimized away from |
| constexpr functions. */ |
| case IFN_UBSAN_NULL: |
| case IFN_UBSAN_BOUNDS: |
| case IFN_UBSAN_VPTR: |
| case IFN_FALLTHROUGH: |
| return true; |
| |
| case IFN_ADD_OVERFLOW: |
| case IFN_SUB_OVERFLOW: |
| case IFN_MUL_OVERFLOW: |
| case IFN_LAUNDER: |
| case IFN_VEC_CONVERT: |
| bail = false; |
| break; |
| |
| default: |
| break; |
| } |
| |
| if (bail) |
| { |
| /* fold_call_expr can't do anything with IFN calls. */ |
| if (flags & tf_error) |
| error_at (loc, "call to internal function %qE", t); |
| return false; |
| } |
| } |
| |
| if (fun && is_overloaded_fn (fun)) |
| { |
| if (TREE_CODE (fun) == FUNCTION_DECL) |
| { |
| if (builtin_valid_in_constant_expr_p (fun)) |
| return true; |
| if (!maybe_constexpr_fn (fun) |
| /* Allow any built-in function; if the expansion |
| isn't constant, we'll deal with that then. */ |
| && !fndecl_built_in_p (fun) |
| /* In C++20, replaceable global allocation functions |
| are constant expressions. */ |
| && (/* !cxx_replaceable_global_alloc_fn (fun) |
| ||*/ TREE_CODE (t) != CALL_EXPR |
| || (!CALL_FROM_NEW_OR_DELETE_P (t) |
| && (current_function_decl == NULL_TREE |
| /*|| !is_std_allocator_allocate(current_function_decl)*/))) |
| /* Allow placement new in std::construct_at. */ |
| && (/*!cxx_placement_new_fn (fun) |
| ||*/ TREE_CODE (t) != CALL_EXPR |
| || current_function_decl == NULL_TREE |
| /*|| !is_std_construct_at (current_function_decl)*/) |
| /* && !cxx_dynamic_cast_fn_p (fun)*/) |
| { |
| if (flags & tf_error) |
| { |
| error_at (loc, "call to non-%<constexpr%> function %qD", |
| fun); |
| explain_invalid_constexpr_fn (fun); |
| } |
| return false; |
| } |
| /* A call to a non-static member function takes the address |
| of the object as the first argument. But in a constant |
| expression the address will be folded away, so look |
| through it now. */ |
| if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) |
| && !DECL_CONSTRUCTOR_P (fun)) |
| { |
| tree x = CALL_EXPR_ARG (t, 0); |
| |
| /* Don't require an immediately constant value, as |
| constexpr substitution might not use the value. */ |
| bool sub_now = false; |
| if (!potential_constant_expression_1 (x, rval, strict, |
| sub_now, flags, |
| jump_target)) |
| return false; |
| i = 1; |
| } |
| } |
| else |
| { |
| if (!RECUR (fun, true)) |
| return false; |
| fun = get_first_fn (fun); |
| } |
| fun = DECL_ORIGIN (fun); |
| } |
| else if (fun) |
| { |
| if (RECUR (fun, rval)) |
| /* Might end up being a constant function pointer. */; |
| else |
| return false; |
| } |
| for (; i < nargs; ++i) |
| { |
| tree x = CALL_EXPR_ARG (t, i); |
| /* In a template, reference arguments haven't been converted to |
| REFERENCE_TYPE and we might not even know if the parameter |
| is a reference, so accept lvalue constants too. */ |
| bool rv = rval; |
| /* Don't require an immediately constant value, as constexpr |
| substitution might not use the value of the argument. */ |
| bool sub_now = false; |
| if (!potential_constant_expression_1 (x, rv, strict, sub_now, flags, |
| jump_target)) |
| return false; |
| } |
| return true; |
| } |
| |
| case NON_LVALUE_EXPR: |
| /* -- an lvalue-to-rvalue conversion (4.1) unless it is applied to |
| -- an lvalue of integral type that refers to a non-volatile |
| const variable or static data member initialized with |
| constant expressions, or |
| |
| -- an lvalue of literal type that refers to non-volatile |
| object defined with constexpr, or that refers to a |
| sub-object of such an object; */ |
| return RECUR (TREE_OPERAND (t, 0), rval); |
| |
| case VAR_DECL: |
| if (DECL_HAS_VALUE_EXPR_P (t)) |
| { |
| return RECUR (DECL_VALUE_EXPR (t), rval); |
| } |
| if (want_rval && !var_in_maybe_constexpr_fn (t) |
| && !decl_maybe_constant_var_p (t) |
| && (strict || !RS_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t)) |
| || (DECL_INITIAL (t) |
| && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t))) |
| && COMPLETE_TYPE_P (TREE_TYPE (t)) |
| && !is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/ false)) |
| { |
| if (flags & tf_error) |
| non_const_var_error (loc, t); |
| return false; |
| } |
| return true; |
| |
| /* FALLTHRU */ |
| case NOP_EXPR: |
| case CONVERT_EXPR: |
| case VIEW_CONVERT_EXPR: |
| /* -- a reinterpret_cast. FIXME not implemented, and this rule |
| may change to something more specific to type-punning (DR 1312). */ |
| { |
| tree from = TREE_OPERAND (t, 0); |
| if (location_wrapper_p (t)) |
| return (RECUR (from, want_rval)); |
| if (INDIRECT_TYPE_P (TREE_TYPE (t))) |
| { |
| STRIP_ANY_LOCATION_WRAPPER (from); |
| if (TREE_CODE (from) == INTEGER_CST && !integer_zerop (from)) |
| { |
| if (flags & tf_error) |
| error_at (loc, |
| "%<reinterpret_cast%> from integer to pointer"); |
| return false; |
| } |
| } |
| return (RECUR (from, TREE_CODE (t) != VIEW_CONVERT_EXPR)); |
| } |
| |
| case ADDR_EXPR: |
| /* -- a unary operator & that is applied to an lvalue that |
| designates an object with thread or automatic storage |
| duration; */ |
| t = TREE_OPERAND (t, 0); |
| |
| if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t)) |
| /* A pointer-to-member constant. */ |
| return true; |
| |
| // handle_addr_expr: |
| #if 0 |
| /* FIXME adjust when issue 1197 is fully resolved. For now don't do |
| any checking here, as we might dereference the pointer later. If |
| we remove this code, also remove check_automatic_or_tls. */ |
| i = check_automatic_or_tls (t); |
| if (i == ck_ok) |
| return true; |
| if (i == ck_bad) |
| { |
| if (flags & tf_error) |
| error ("address-of an object %qE with thread local or " |
| "automatic storage is not a constant expression", t); |
| return false; |
| } |
| #endif |
| return RECUR (t, any); |
| |
| case COMPONENT_REF: |
| /* -- a class member access unless its postfix-expression is |
| of literal type or of pointer to literal type. */ |
| /* This test would be redundant, as it follows from the |
| postfix-expression being a potential constant expression. */ |
| if (type_unknown_p (t)) |
| return true; |
| if (is_overloaded_fn (t)) |
| /* In a template, a COMPONENT_REF of a function expresses ob.fn(), |
| which uses ob as an lvalue. */ |
| want_rval = false; |
| gcc_fallthrough (); |
| |
| case REALPART_EXPR: |
| case IMAGPART_EXPR: |
| case BIT_FIELD_REF: |
| return RECUR (TREE_OPERAND (t, 0), want_rval); |
| |
| case INDIRECT_REF: { |
| tree x = TREE_OPERAND (t, 0); |
| STRIP_NOPS (x); |
| return RECUR (x, rval); |
| } |
| |
| case STATEMENT_LIST: |
| for (tree stmt : tsi_range (t)) |
| if (!RECUR (stmt, any)) |
| return false; |
| return true; |
| |
| case MODIFY_EXPR: |
| if (!RECUR (TREE_OPERAND (t, 0), any)) |
| return false; |
| /* Just ignore clobbers. */ |
| if (TREE_CLOBBER_P (TREE_OPERAND (t, 1))) |
| return true; |
| if (!RECUR (TREE_OPERAND (t, 1), rval)) |
| return false; |
| return true; |
| |
| case FOR_STMT: |
| if (!RECUR (FOR_INIT_STMT (t), any)) |
| return false; |
| tmp = FOR_COND (t); |
| if (!RECUR (tmp, rval)) |
| return false; |
| if (tmp) |
| { |
| tmp = cxx_eval_outermost_constant_expr (tmp, true); |
| /* If we couldn't evaluate the condition, it might not ever be |
| true. */ |
| if (!integer_onep (tmp)) |
| { |
| /* Before returning true, check if the for body can contain |
| a return. */ |
| hash_set<tree> pset; |
| check_for_return_continue_data data |
| = {&pset, NULL_TREE, NULL_TREE}; |
| if (tree ret_expr |
| = rs_walk_tree (&FOR_BODY (t), check_for_return_continue, |
| &data, &pset)) |
| *jump_target = ret_expr; |
| return true; |
| } |
| } |
| if (!RECUR (FOR_EXPR (t), any)) |
| return false; |
| if (!RECUR (FOR_BODY (t), any)) |
| return false; |
| if (breaks (jump_target) || continues (jump_target)) |
| *jump_target = NULL_TREE; |
| return true; |
| |
| case WHILE_STMT: |
| tmp = WHILE_COND (t); |
| if (!RECUR (tmp, rval)) |
| return false; |
| |
| tmp = cxx_eval_outermost_constant_expr (tmp, true); |
| /* If we couldn't evaluate the condition, it might not ever be true. */ |
| if (!integer_onep (tmp)) |
| { |
| /* Before returning true, check if the while body can contain |
| a return. */ |
| hash_set<tree> pset; |
| check_for_return_continue_data data = {&pset, NULL_TREE, NULL_TREE}; |
| if (tree ret_expr |
| = rs_walk_tree (&WHILE_BODY (t), check_for_return_continue, &data, |
| &pset)) |
| *jump_target = ret_expr; |
| return true; |
| } |
| if (!RECUR (WHILE_BODY (t), any)) |
| return false; |
| if (breaks (jump_target) || continues (jump_target)) |
| *jump_target = NULL_TREE; |
| return true; |
| |
| case SWITCH_STMT: |
| if (!RECUR (SWITCH_STMT_COND (t), rval)) |
| return false; |
| /* FIXME we don't check SWITCH_STMT_BODY currently, because even |
| unreachable labels would be checked and it is enough if there is |
| a single switch cond value for which it is a valid constant |
| expression. We need to check if there are any RETURN_EXPRs |
| or CONTINUE_STMTs inside of the body though, as in that case |
| we need to set *jump_target. */ |
| else |
| { |
| hash_set<tree> pset; |
| check_for_return_continue_data data = {&pset, NULL_TREE, NULL_TREE}; |
| if (tree ret_expr |
| = rs_walk_tree (&SWITCH_STMT_BODY (t), check_for_return_continue, |
| &data, &pset)) |
| /* The switch might return. */ |
| *jump_target = ret_expr; |
| else if (data.continue_stmt) |
| /* The switch can't return, but might continue. */ |
| *jump_target = data.continue_stmt; |
| } |
| return true; |
| |
| case DYNAMIC_CAST_EXPR: |
| case PSEUDO_DTOR_EXPR: |
| case NEW_EXPR: |
| case VEC_NEW_EXPR: |
| case DELETE_EXPR: |
| case VEC_DELETE_EXPR: |
| case THROW_EXPR: |
| case OMP_PARALLEL: |
| case OMP_TASK: |
| case OMP_FOR: |
| case OMP_SIMD: |
| case OMP_DISTRIBUTE: |
| case OMP_TASKLOOP: |
| case OMP_LOOP: |
| case OMP_TEAMS: |
| case OMP_TARGET_DATA: |
| case OMP_TARGET: |
| case OMP_SECTIONS: |
| case OMP_ORDERED: |
| case OMP_CRITICAL: |
| case OMP_SINGLE: |
| case OMP_SECTION: |
| case OMP_MASTER: |
| case OMP_MASKED: |
| case OMP_TASKGROUP: |
| case OMP_TARGET_UPDATE: |
| case OMP_TARGET_ENTER_DATA: |
| case OMP_TARGET_EXIT_DATA: |
| case OMP_ATOMIC: |
| case OMP_ATOMIC_READ: |
| case OMP_ATOMIC_CAPTURE_OLD: |
| case OMP_ATOMIC_CAPTURE_NEW: |
| case OMP_DEPOBJ: |
| case OACC_PARALLEL: |
| case OACC_KERNELS: |
| case OACC_SERIAL: |
| case OACC_DATA: |
| case OACC_HOST_DATA: |
| case OACC_LOOP: |
| case OACC_CACHE: |
| case OACC_DECLARE: |
| case OACC_ENTER_DATA: |
| case OACC_EXIT_DATA: |
| case OACC_UPDATE: |
| /* GCC internal stuff. */ |
| case VA_ARG_EXPR: |
| case TRANSACTION_EXPR: |
| case AT_ENCODE_EXPR: |
| |
| if (flags & tf_error) |
| error_at (loc, "expression %qE is not a constant expression", t); |
| return false; |
| |
| case ASM_EXPR: |
| if (flags & tf_error) |
| inline_asm_in_constexpr_error (loc); |
| return false; |
| |
| case OBJ_TYPE_REF: |
| return true; |
| |
| case POINTER_DIFF_EXPR: |
| case MINUS_EXPR: |
| want_rval = true; |
| goto binary; |
| |
| case LT_EXPR: |
| case LE_EXPR: |
| case GT_EXPR: |
| case GE_EXPR: |
| case EQ_EXPR: |
| case NE_EXPR: |
| case SPACESHIP_EXPR: |
| want_rval = true; |
| goto binary; |
| |
| case PREINCREMENT_EXPR: |
| case POSTINCREMENT_EXPR: |
| case PREDECREMENT_EXPR: |
| case POSTDECREMENT_EXPR: |
| goto unary; |
| |
| case BIT_NOT_EXPR: |
| /* A destructor. */ |
| if (TYPE_P (TREE_OPERAND (t, 0))) |
| return true; |
| /* fall through. */ |
| |
| case CONJ_EXPR: |
| case SAVE_EXPR: |
| case FIX_TRUNC_EXPR: |
| case FLOAT_EXPR: |
| case NEGATE_EXPR: |
| case ABS_EXPR: |
| case ABSU_EXPR: |
| case TRUTH_NOT_EXPR: |
| case FIXED_CONVERT_EXPR: |
| case UNARY_PLUS_EXPR: |
| case UNARY_LEFT_FOLD_EXPR: |
| case UNARY_RIGHT_FOLD_EXPR: |
| unary: |
| return RECUR (TREE_OPERAND (t, 0), rval); |
| |
| case BIND_EXPR: |
| return RECUR (BIND_EXPR_BODY (t), want_rval); |
| |
| case CLEANUP_POINT_EXPR: |
| case EXPR_STMT: |
| case PAREN_EXPR: |
| /* For convenience. */ |
| case LOOP_EXPR: |
| case EXIT_EXPR: |
| return RECUR (TREE_OPERAND (t, 0), want_rval); |
| |
| case DECL_EXPR: |
| tmp = DECL_EXPR_DECL (t); |
| if (VAR_P (tmp) && !DECL_ARTIFICIAL (tmp)) |
| { |
| if (RS_DECL_THREAD_LOCAL_P (tmp)) |
| { |
| if (flags & tf_error) |
| error_at (DECL_SOURCE_LOCATION (tmp), |
| "%qD declared " |
| "%<thread_local%> in %<constexpr%> context", |
| tmp); |
| return false; |
| } |
| else if (TREE_STATIC (tmp)) |
| { |
| if (flags & tf_error) |
| error_at (DECL_SOURCE_LOCATION (tmp), |
| "%qD declared " |
| "%<static%> in %<constexpr%> context", |
| tmp); |
| return false; |
| } |
| else if (!check_for_uninitialized_const_var ( |
| tmp, /*constexpr_context_p=*/true, flags)) |
| return false; |
| } |
| return RECUR (tmp, want_rval); |
| |
| case TRY_FINALLY_EXPR: |
| return (RECUR (TREE_OPERAND (t, 0), want_rval) |
| && RECUR (TREE_OPERAND (t, 1), any)); |
| |
| case SCOPE_REF: |
| return RECUR (TREE_OPERAND (t, 1), want_rval); |
| |
| case TARGET_EXPR: |
| if (!TARGET_EXPR_DIRECT_INIT_P (t) && !literal_type_p (TREE_TYPE (t))) |
| { |
| if (flags & tf_error) |
| { |
| auto_diagnostic_group d; |
| error_at (loc, |
| "temporary of non-literal type %qT in a " |
| "constant expression", |
| TREE_TYPE (t)); |
| explain_non_literal_class (TREE_TYPE (t)); |
| } |
| return false; |
| } |
| /* FALLTHRU */ |
| case INIT_EXPR: |
| return RECUR (TREE_OPERAND (t, 1), rval); |
| |
| case CONSTRUCTOR: { |
| vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); |
| constructor_elt *ce; |
| for (i = 0; vec_safe_iterate (v, i, &ce); ++i) |
| if (!RECUR (ce->value, want_rval)) |
| return false; |
| return true; |
| } |
| |
| case TREE_LIST: { |
| gcc_assert (TREE_PURPOSE (t) == NULL_TREE || DECL_P (TREE_PURPOSE (t))); |
| if (!RECUR (TREE_VALUE (t), want_rval)) |
| return false; |
| if (TREE_CHAIN (t) == NULL_TREE) |
| return true; |
| return RECUR (TREE_CHAIN (t), want_rval); |
| } |
| |
| case TRUNC_DIV_EXPR: |
| case CEIL_DIV_EXPR: |
| case FLOOR_DIV_EXPR: |
| case ROUND_DIV_EXPR: |
| case TRUNC_MOD_EXPR: |
| case CEIL_MOD_EXPR: |
| case ROUND_MOD_EXPR: { |
| tree denom = TREE_OPERAND (t, 1); |
| if (!RECUR (denom, rval)) |
| return false; |
| /* We can't call cxx_eval_outermost_constant_expr on an expression |
| that hasn't been through instantiate_non_dependent_expr yet. */ |
| denom = cxx_eval_outermost_constant_expr (denom, true); |
| if (integer_zerop (denom)) |
| { |
| if (flags & tf_error) |
| error ("division by zero is not a constant expression"); |
| return false; |
| } |
| else |
| { |
| want_rval = true; |
| return RECUR (TREE_OPERAND (t, 0), want_rval); |
| } |
| } |
| |
| case COMPOUND_EXPR: { |
| /* check_return_expr sometimes wraps a TARGET_EXPR in a |
| COMPOUND_EXPR; don't get confused. */ |
| tree op0 = TREE_OPERAND (t, 0); |
| tree op1 = TREE_OPERAND (t, 1); |
| STRIP_NOPS (op1); |
| if (TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) |
| return RECUR (op0, want_rval); |
| else |
| goto binary; |
| } |
| |
| /* If the first operand is the non-short-circuit constant, look at |
| the second operand; otherwise we only care about the first one for |
| potentiality. */ |
| case TRUTH_AND_EXPR: |
| case TRUTH_ANDIF_EXPR: |
| tmp = boolean_true_node; |
| goto truth; |
| case TRUTH_OR_EXPR: |
| case TRUTH_ORIF_EXPR: |
| tmp = boolean_false_node; |
| truth : { |
| tree op0 = TREE_OPERAND (t, 0); |
| tree op1 = TREE_OPERAND (t, 1); |
| if (!RECUR (op0, rval)) |
| return false; |
| if (!(flags & tf_error) && RECUR (op1, rval)) |
| /* When quiet, try to avoid expensive trial evaluation by first |
| checking potentiality of the second operand. */ |
| return true; |
| op0 = cxx_eval_outermost_constant_expr (op0, true); |
| if (tree_int_cst_equal (op0, tmp)) |
| return (flags & tf_error) ? RECUR (op1, rval) : false; |
| else |
| return true; |
| } |
| |
| case PLUS_EXPR: |
| case MULT_EXPR: |
| case POINTER_PLUS_EXPR: |
| case RDIV_EXPR: |
| case EXACT_DIV_EXPR: |
| case MIN_EXPR: |
| case MAX_EXPR: |
| case LSHIFT_EXPR: |
| case RSHIFT_EXPR: |
| case LROTATE_EXPR: |
| case RROTATE_EXPR: |
| case BIT_IOR_EXPR: |
| case BIT_XOR_EXPR: |
| case BIT_AND_EXPR: |
| case TRUTH_XOR_EXPR: |
| case UNORDERED_EXPR: |
| case ORDERED_EXPR: |
| case UNLT_EXPR: |
| case UNLE_EXPR: |
| case UNGT_EXPR: |
| case UNGE_EXPR: |
| case UNEQ_EXPR: |
| case LTGT_EXPR: |
| case RANGE_EXPR: |
| case COMPLEX_EXPR: |
| want_rval = true; |
| /* Fall through. */ |
| case ARRAY_REF: |
| case ARRAY_RANGE_REF: |
| case MEMBER_REF: |
| case DOTSTAR_EXPR: |
| case MEM_REF: |
| case BINARY_LEFT_FOLD_EXPR: |
| case BINARY_RIGHT_FOLD_EXPR: |
| binary: |
| for (i = 0; i < 2; ++i) |
| if (!RECUR (TREE_OPERAND (t, i), want_rval)) |
| return false; |
| return true; |
| |
| case VEC_PERM_EXPR: |
| for (i = 0; i < 3; ++i) |
| if (!RECUR (TREE_OPERAND (t, i), true)) |
| return false; |
| return true; |
| |
| case COND_EXPR: |
| if (COND_EXPR_IS_VEC_DELETE (t)) |
| { |
| if (flags & tf_error) |
| error_at (loc, "%<delete[]%> is not a constant expression"); |
| return false; |
| } |
| /* Fall through. */ |
| case IF_STMT: |
| case VEC_COND_EXPR: |
| /* If the condition is a known constant, we know which of the legs we |
| care about; otherwise we only require that the condition and |
| either of the legs be potentially constant. */ |
| tmp = TREE_OPERAND (t, 0); |
| if (!RECUR (tmp, rval)) |
| return false; |
| |
| tmp = cxx_eval_outermost_constant_expr (tmp, true); |
| /* potential_constant_expression* isn't told if it is called for |
| manifestly_const_eval or not, so for consteval if always |
| process both branches as if the condition is not a known |
| constant. */ |
| if (TREE_CODE (t) != IF_STMT || !IF_STMT_CONSTEVAL_P (t)) |
| { |
| if (integer_zerop (tmp)) |
| return RECUR (TREE_OPERAND (t, 2), want_rval); |
| else if (TREE_CODE (tmp) == INTEGER_CST) |
| return RECUR (TREE_OPERAND (t, 1), want_rval); |
| } |
| tmp = *jump_target; |
| for (i = 1; i < 3; ++i) |
| { |
| tree this_jump_target = tmp; |
| if (potential_constant_expression_1 (TREE_OPERAND (t, i), want_rval, |
| strict, now, tf_none, |
| &this_jump_target)) |
| { |
| if (returns (&this_jump_target)) |
| *jump_target = this_jump_target; |
| else if (!returns (jump_target)) |
| { |
| if (breaks (&this_jump_target) |
| || continues (&this_jump_target)) |
| *jump_target = this_jump_target; |
| if (i == 1) |
| { |
| /* If the then branch is potentially constant, but |
| does not return, check if the else branch |
| couldn't return, break or continue. */ |
| hash_set<tree> pset; |
| check_for_return_continue_data data |
| = {&pset, NULL_TREE, NULL_TREE}; |
| if (tree ret_expr |
| = rs_walk_tree (&TREE_OPERAND (t, 2), |
| check_for_return_continue, &data, |
| &pset)) |
| *jump_target = ret_expr; |
| else if (*jump_target == NULL_TREE) |
| { |
| if (data.continue_stmt) |
| *jump_target = data.continue_stmt; |
| else if (data.break_stmt) |
| *jump_target = data.break_stmt; |
| } |
| } |
| } |
| return true; |
| } |
| } |
| if (flags & tf_error) |
| error_at (loc, "expression %qE is not a constant expression", t); |
| return false; |
| |
| case TYPE_DECL: |
| /* We can see these in statement-expressions. */ |
| return true; |
| |
| case LABEL_EXPR: |
| t = LABEL_EXPR_LABEL (t); |
| if (DECL_ARTIFICIAL (t)) |
| return true; |
| else if (flags & tf_error) |
| error_at (loc, "label definition in %<constexpr%> function only " |
| "available with %<-std=c++2b%> or %<-std=gnu++2b%>"); |
| return false; |
| |
| case ANNOTATE_EXPR: |
| return RECUR (TREE_OPERAND (t, 0), rval); |
| |
| case BIT_CAST_EXPR: |
| return RECUR (TREE_OPERAND (t, 0), rval); |
| |
| default: |
| sorry ("unexpected AST of kind %s", get_tree_code_name (TREE_CODE (t))); |
| rust_unreachable (); |
| return false; |
| } |
| #undef RECUR |
| } |
| |
| bool |
| potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, |
| tsubst_flags_t flags) |
| { |
| if (flags & tf_error) |
| { |
| /* Check potentiality quietly first, as that could be performed more |
| efficiently in some cases (currently only for TRUTH_*_EXPR). If |
| that fails, replay the check noisily to give errors. */ |
| flags &= ~tf_error; |
| if (potential_constant_expression_1 (t, want_rval, strict, now, flags)) |
| return true; |
| flags |= tf_error; |
| } |
| |
| tree target = NULL_TREE; |
| return potential_constant_expression_1 (t, want_rval, strict, now, flags, |
| &target); |
| } |
| |
| // forked from gcc/cp/constexpr.cc fold_non_dependent_init |
| |
| /* Like maybe_constant_init but first fully instantiate the argument. */ |
| |
| tree |
| fold_non_dependent_init (tree t, tsubst_flags_t /*=tf_warning_or_error*/, |
| bool manifestly_const_eval /*=false*/, |
| tree object /* = NULL_TREE */) |
| { |
| if (t == NULL_TREE) |
| return NULL_TREE; |
| |
| return maybe_constant_init (t, object, manifestly_const_eval); |
| } |
| |
| } // namespace Compile |
| } // namespace Rust |
| |
| using namespace Rust::Compile; |
| |
| #include "gt-rust-rust-constexpr.h" |