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Diffstat (limited to 'gcc/ada/gcc-interface/utils2.c')
| -rw-r--r-- | gcc/ada/gcc-interface/utils2.c | 3050 |
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diff --git a/gcc/ada/gcc-interface/utils2.c b/gcc/ada/gcc-interface/utils2.c deleted file mode 100644 index b651d48..0000000 --- a/gcc/ada/gcc-interface/utils2.c +++ /dev/null @@ -1,3050 +0,0 @@ -/**************************************************************************** - * * - * GNAT COMPILER COMPONENTS * - * * - * U T I L S 2 * - * * - * C Implementation File * - * * - * Copyright (C) 1992-2022, Free Software Foundation, Inc. * - * * - * GNAT is free software; you can redistribute it and/or modify it under * - * terms of the GNU General Public License as published by the Free Soft- * - * ware Foundation; either version 3, or (at your option) any later ver- * - * sion. GNAT is distributed in the hope that it will be useful, but WITH- * - * OUT 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/>. * - * * - * GNAT was originally developed by the GNAT team at New York University. * - * Extensive contributions were provided by Ada Core Technologies Inc. * - * * - ****************************************************************************/ - -#include "config.h" -#include "system.h" -#include "coretypes.h" -#include "memmodel.h" -#include "tm.h" -#include "vec.h" -#include "alias.h" -#include "tree.h" -#include "inchash.h" -#include "builtins.h" -#include "fold-const.h" -#include "stor-layout.h" -#include "stringpool.h" -#include "varasm.h" -#include "flags.h" -#include "toplev.h" -#include "ggc.h" -#include "tree-inline.h" - -#include "ada.h" -#include "types.h" -#include "atree.h" -#include "elists.h" -#include "namet.h" -#include "nlists.h" -#include "snames.h" -#include "stringt.h" -#include "uintp.h" -#include "fe.h" -#include "sinfo.h" -#include "einfo.h" -#include "ada-tree.h" -#include "gigi.h" - -/* Return the base type of TYPE. */ - -tree -get_base_type (tree type) -{ - if (TREE_CODE (type) == RECORD_TYPE - && TYPE_JUSTIFIED_MODULAR_P (type)) - type = TREE_TYPE (TYPE_FIELDS (type)); - - while (TREE_TYPE (type) - && (TREE_CODE (type) == INTEGER_TYPE - || TREE_CODE (type) == REAL_TYPE)) - type = TREE_TYPE (type); - - return type; -} - -/* EXP is a GCC tree representing an address. See if we can find how strictly - the object at this address is aligned and, if so, return the alignment of - the object in bits. Otherwise return 0. */ - -unsigned int -known_alignment (tree exp) -{ - unsigned int this_alignment; - unsigned int lhs, rhs; - - switch (TREE_CODE (exp)) - { - CASE_CONVERT: - case VIEW_CONVERT_EXPR: - case NON_LVALUE_EXPR: - /* Conversions between pointers and integers don't change the alignment - of the underlying object. */ - this_alignment = known_alignment (TREE_OPERAND (exp, 0)); - break; - - case COMPOUND_EXPR: - /* The value of a COMPOUND_EXPR is that of its second operand. */ - this_alignment = known_alignment (TREE_OPERAND (exp, 1)); - break; - - case PLUS_EXPR: - case MINUS_EXPR: - /* If two addresses are added, the alignment of the result is the - minimum of the two alignments. */ - lhs = known_alignment (TREE_OPERAND (exp, 0)); - rhs = known_alignment (TREE_OPERAND (exp, 1)); - this_alignment = MIN (lhs, rhs); - break; - - case POINTER_PLUS_EXPR: - /* If this is the pattern built for aligning types, decode it. */ - if (TREE_CODE (TREE_OPERAND (exp, 1)) == BIT_AND_EXPR - && TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 1), 0)) == NEGATE_EXPR) - { - tree op = TREE_OPERAND (TREE_OPERAND (exp, 1), 1); - return - known_alignment (fold_build1 (BIT_NOT_EXPR, TREE_TYPE (op), op)); - } - - /* If we don't know the alignment of the offset, we assume that - of the base. */ - lhs = known_alignment (TREE_OPERAND (exp, 0)); - rhs = known_alignment (TREE_OPERAND (exp, 1)); - - if (rhs == 0) - this_alignment = lhs; - else - this_alignment = MIN (lhs, rhs); - break; - - case COND_EXPR: - /* If there is a choice between two values, use the smaller one. */ - lhs = known_alignment (TREE_OPERAND (exp, 1)); - rhs = known_alignment (TREE_OPERAND (exp, 2)); - this_alignment = MIN (lhs, rhs); - break; - - case INTEGER_CST: - { - unsigned HOST_WIDE_INT c = TREE_INT_CST_LOW (exp); - /* The first part of this represents the lowest bit in the constant, - but it is originally in bytes, not bits. */ - this_alignment = (c & -c) * BITS_PER_UNIT; - } - break; - - case MULT_EXPR: - /* If we know the alignment of just one side, use it. Otherwise, - use the product of the alignments. */ - lhs = known_alignment (TREE_OPERAND (exp, 0)); - rhs = known_alignment (TREE_OPERAND (exp, 1)); - - if (lhs == 0) - this_alignment = rhs; - else if (rhs == 0) - this_alignment = lhs; - else - this_alignment = MIN (lhs * rhs, BIGGEST_ALIGNMENT); - break; - - case BIT_AND_EXPR: - /* A bit-and expression is as aligned as the maximum alignment of the - operands. We typically get here for a complex lhs and a constant - negative power of two on the rhs to force an explicit alignment, so - don't bother looking at the lhs. */ - this_alignment = known_alignment (TREE_OPERAND (exp, 1)); - break; - - case ADDR_EXPR: - if (DECL_P (TREE_OPERAND (exp, 0))) - this_alignment = DECL_ALIGN (TREE_OPERAND (exp, 0)); - else - this_alignment = get_object_alignment (TREE_OPERAND (exp, 0)); - break; - - case CALL_EXPR: - { - tree fndecl = get_callee_fndecl (exp); - if (fndecl == malloc_decl || fndecl == realloc_decl) - return get_target_system_allocator_alignment () * BITS_PER_UNIT; - - tree t = maybe_inline_call_in_expr (exp); - if (t) - return known_alignment (t); - } - - /* ... fall through ... */ - - default: - /* For other pointer expressions, we assume that the pointed-to object - is at least as aligned as the pointed-to type. Beware that we can - have a dummy type here (e.g. a Taft Amendment type), for which the - alignment is meaningless and should be ignored. */ - if (POINTER_TYPE_P (TREE_TYPE (exp)) - && !TYPE_IS_DUMMY_P (TREE_TYPE (TREE_TYPE (exp))) - && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (exp)))) - this_alignment = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))); - else - this_alignment = 0; - break; - } - - return this_alignment; -} - -/* We have a comparison or assignment operation on two types, T1 and T2, which - are either both array types or both record types. T1 is assumed to be for - the left hand side operand, and T2 for the right hand side. Return the - type that both operands should be converted to for the operation, if any. - Otherwise return zero. */ - -static tree -find_common_type (tree t1, tree t2) -{ - /* ??? As of today, various constructs lead to here with types of different - sizes even when both constants (e.g. tagged types, packable vs regular - component types, padded vs unpadded types, ...). While some of these - would better be handled upstream (types should be made consistent before - calling into build_binary_op), some others are really expected and we - have to be careful. */ - - const bool variable_record_on_lhs - = (TREE_CODE (t1) == RECORD_TYPE - && TREE_CODE (t2) == RECORD_TYPE - && get_variant_part (t1) - && !get_variant_part (t2)); - - const bool variable_array_on_lhs - = (TREE_CODE (t1) == ARRAY_TYPE - && TREE_CODE (t2) == ARRAY_TYPE - && !TREE_CONSTANT (TYPE_MIN_VALUE (TYPE_DOMAIN (t1))) - && TREE_CONSTANT (TYPE_MIN_VALUE (TYPE_DOMAIN (t2)))); - - /* We must avoid writing more than what the target can hold if this is for - an assignment and the case of tagged types is handled in build_binary_op - so we use the lhs type if it is known to be smaller or of constant size - and the rhs type is not, whatever the modes. We also force t1 in case of - constant size equality to minimize occurrences of view conversions on the - lhs of an assignment, except for the case of types with a variable part - on the lhs but not on the rhs to make the conversion simpler. */ - if (TREE_CONSTANT (TYPE_SIZE (t1)) - && (!TREE_CONSTANT (TYPE_SIZE (t2)) - || tree_int_cst_lt (TYPE_SIZE (t1), TYPE_SIZE (t2)) - || (TYPE_SIZE (t1) == TYPE_SIZE (t2) - && !variable_record_on_lhs - && !variable_array_on_lhs))) - return t1; - - /* Otherwise, if the lhs type is non-BLKmode, use it, except for the case of - a non-BLKmode rhs and array types with a variable part on the lhs but not - on the rhs to make sure the conversion is preserved during gimplification. - Note that we know that we will not have any alignment problems since, if - we did, the non-BLKmode type could not have been used. */ - if (TYPE_MODE (t1) != BLKmode - && (TYPE_MODE (t2) == BLKmode || !variable_array_on_lhs)) - return t1; - - /* If the rhs type is of constant size, use it whatever the modes. At - this point it is known to be smaller, or of constant size and the - lhs type is not. */ - if (TREE_CONSTANT (TYPE_SIZE (t2))) - return t2; - - /* Otherwise, if the rhs type is non-BLKmode, use it. */ - if (TYPE_MODE (t2) != BLKmode) - return t2; - - /* In this case, both types have variable size and BLKmode. It's - probably best to leave the "type mismatch" because changing it - could cause a bad self-referential reference. */ - return NULL_TREE; -} - -/* Return an expression tree representing an equality comparison of A1 and A2, - two objects of type ARRAY_TYPE. The result should be of type RESULT_TYPE. - - Two arrays are equal in one of two ways: (1) if both have zero length in - some dimension (not necessarily the same dimension) or (2) if the lengths - in each dimension are equal and the data is equal. We perform the length - tests in as efficient a manner as possible. */ - -static tree -compare_arrays (location_t loc, tree result_type, tree a1, tree a2) -{ - tree result = convert (result_type, boolean_true_node); - tree a1_is_null = convert (result_type, boolean_false_node); - tree a2_is_null = convert (result_type, boolean_false_node); - tree t1 = TREE_TYPE (a1); - tree t2 = TREE_TYPE (a2); - bool a1_side_effects_p = TREE_SIDE_EFFECTS (a1); - bool a2_side_effects_p = TREE_SIDE_EFFECTS (a2); - bool length_zero_p = false; - - /* If the operands have side-effects, they need to be evaluated only once - in spite of the multiple references in the comparison. */ - if (a1_side_effects_p) - a1 = gnat_protect_expr (a1); - - if (a2_side_effects_p) - a2 = gnat_protect_expr (a2); - - /* Process each dimension separately and compare the lengths. If any - dimension has a length known to be zero, set LENGTH_ZERO_P to true - in order to suppress the comparison of the data at the end. */ - while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE) - { - tree dom1 = TYPE_DOMAIN (t1); - tree dom2 = TYPE_DOMAIN (t2); - tree length1 = size_binop (PLUS_EXPR, - size_binop (MINUS_EXPR, - TYPE_MAX_VALUE (dom1), - TYPE_MIN_VALUE (dom1)), - size_one_node); - tree length2 = size_binop (PLUS_EXPR, - size_binop (MINUS_EXPR, - TYPE_MAX_VALUE (dom2), - TYPE_MIN_VALUE (dom2)), - size_one_node); - tree ind1 = TYPE_INDEX_TYPE (dom1); - tree ind2 = TYPE_INDEX_TYPE (dom2); - tree base_type = maybe_character_type (get_base_type (ind1)); - tree lb1 = convert (base_type, TYPE_MIN_VALUE (ind1)); - tree ub1 = convert (base_type, TYPE_MAX_VALUE (ind1)); - tree lb2 = convert (base_type, TYPE_MIN_VALUE (ind2)); - tree ub2 = convert (base_type, TYPE_MAX_VALUE (ind2)); - tree comparison, this_a1_is_null, this_a2_is_null; - - /* If the length of the first array is a constant and that of the second - array is not, swap our operands to have the constant second. */ - if (TREE_CODE (length1) == INTEGER_CST - && TREE_CODE (length2) != INTEGER_CST) - { - tree tem; - bool btem; - - tem = a1, a1 = a2, a2 = tem; - tem = t1, t1 = t2, t2 = tem; - tem = lb1, lb1 = lb2, lb2 = tem; - tem = ub1, ub1 = ub2, ub2 = tem; - tem = length1, length1 = length2, length2 = tem; - tem = a1_is_null, a1_is_null = a2_is_null, a2_is_null = tem; - btem = a1_side_effects_p, a1_side_effects_p = a2_side_effects_p, - a2_side_effects_p = btem; - } - - /* If the length of the second array is the constant zero, we can just - use the original stored bounds for the first array and see whether - last < first holds. */ - if (integer_zerop (length2)) - { - length_zero_p = true; - - lb1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (lb1, a1); - ub1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (ub1, a1); - - comparison = fold_build2_loc (loc, LT_EXPR, result_type, ub1, lb1); - if (EXPR_P (comparison)) - SET_EXPR_LOCATION (comparison, loc); - - this_a1_is_null = comparison; - this_a2_is_null = convert (result_type, boolean_true_node); - } - - /* Otherwise, if the length is some other constant value, we know that - this dimension in the second array cannot be superflat, so we can - just use its length computed from the actual stored bounds. */ - else if (TREE_CODE (length2) == INTEGER_CST) - { - /* Note that we know that LB2 and UB2 are constant and hence - cannot contain a PLACEHOLDER_EXPR. */ - lb1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (lb1, a1); - ub1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (ub1, a1); - - comparison - = fold_build2_loc (loc, EQ_EXPR, result_type, - build_binary_op (MINUS_EXPR, base_type, - ub1, lb1), - build_binary_op (MINUS_EXPR, base_type, - ub2, lb2)); - if (EXPR_P (comparison)) - SET_EXPR_LOCATION (comparison, loc); - - this_a1_is_null - = fold_build2_loc (loc, LT_EXPR, result_type, ub1, lb1); - - this_a2_is_null = convert (result_type, boolean_false_node); - } - - /* Otherwise, compare the computed lengths. */ - else - { - length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1); - length2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length2, a2); - - comparison - = fold_build2_loc (loc, EQ_EXPR, result_type, length1, length2); - if (EXPR_P (comparison)) - SET_EXPR_LOCATION (comparison, loc); - - lb1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (lb1, a1); - ub1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (ub1, a1); - - this_a1_is_null - = fold_build2_loc (loc, LT_EXPR, result_type, ub1, lb1); - - lb2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (lb2, a2); - ub2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (ub2, a2); - - this_a2_is_null - = fold_build2_loc (loc, LT_EXPR, result_type, ub2, lb2); - } - - /* Append expressions for this dimension to the final expressions. */ - result = build_binary_op (TRUTH_ANDIF_EXPR, result_type, - result, comparison); - - a1_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type, - this_a1_is_null, a1_is_null); - - a2_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type, - this_a2_is_null, a2_is_null); - - t1 = TREE_TYPE (t1); - t2 = TREE_TYPE (t2); - } - - /* Unless the length of some dimension is known to be zero, compare the - data in the array. */ - if (!length_zero_p) - { - tree type = find_common_type (TREE_TYPE (a1), TREE_TYPE (a2)); - tree comparison; - - if (type) - { - a1 = convert (type, a1), - a2 = convert (type, a2); - } - - comparison = fold_build2_loc (loc, EQ_EXPR, result_type, a1, a2); - - result - = build_binary_op (TRUTH_ANDIF_EXPR, result_type, result, comparison); - } - - /* The result is also true if both sizes are zero. */ - result = build_binary_op (TRUTH_ORIF_EXPR, result_type, - build_binary_op (TRUTH_ANDIF_EXPR, result_type, - a1_is_null, a2_is_null), - result); - - /* If the operands have side-effects, they need to be evaluated before - doing the tests above since the place they otherwise would end up - being evaluated at run time could be wrong. */ - if (a1_side_effects_p) - result = build2 (COMPOUND_EXPR, result_type, a1, result); - - if (a2_side_effects_p) - result = build2 (COMPOUND_EXPR, result_type, a2, result); - - return result; -} - -/* Return an expression tree representing an equality comparison of P1 and P2, - two objects of fat pointer type. The result should be of type RESULT_TYPE. - - Two fat pointers are equal in one of two ways: (1) if both have a null - pointer to the array or (2) if they contain the same couple of pointers. - We perform the comparison in as efficient a manner as possible. */ - -static tree -compare_fat_pointers (location_t loc, tree result_type, tree p1, tree p2) -{ - tree p1_array, p2_array, p1_bounds, p2_bounds, same_array, same_bounds; - tree p1_array_is_null, p2_array_is_null; - - /* If either operand has side-effects, they have to be evaluated only once - in spite of the multiple references to the operand in the comparison. */ - p1 = gnat_protect_expr (p1); - p2 = gnat_protect_expr (p2); - - /* The constant folder doesn't fold fat pointer types so we do it here. */ - if (TREE_CODE (p1) == CONSTRUCTOR) - p1_array = CONSTRUCTOR_ELT (p1, 0)->value; - else - p1_array = build_component_ref (p1, TYPE_FIELDS (TREE_TYPE (p1)), true); - - p1_array_is_null - = fold_build2_loc (loc, EQ_EXPR, result_type, p1_array, - fold_convert_loc (loc, TREE_TYPE (p1_array), - null_pointer_node)); - - if (TREE_CODE (p2) == CONSTRUCTOR) - p2_array = CONSTRUCTOR_ELT (p2, 0)->value; - else - p2_array = build_component_ref (p2, TYPE_FIELDS (TREE_TYPE (p2)), true); - - p2_array_is_null - = fold_build2_loc (loc, EQ_EXPR, result_type, p2_array, - fold_convert_loc (loc, TREE_TYPE (p2_array), - null_pointer_node)); - - /* If one of the pointers to the array is null, just compare the other. */ - if (integer_zerop (p1_array)) - return p2_array_is_null; - else if (integer_zerop (p2_array)) - return p1_array_is_null; - - /* Otherwise, do the fully-fledged comparison. */ - same_array - = fold_build2_loc (loc, EQ_EXPR, result_type, p1_array, p2_array); - - if (TREE_CODE (p1) == CONSTRUCTOR) - p1_bounds = CONSTRUCTOR_ELT (p1, 1)->value; - else - p1_bounds - = build_component_ref (p1, DECL_CHAIN (TYPE_FIELDS (TREE_TYPE (p1))), - true); - - if (TREE_CODE (p2) == CONSTRUCTOR) - p2_bounds = CONSTRUCTOR_ELT (p2, 1)->value; - else - p2_bounds - = build_component_ref (p2, DECL_CHAIN (TYPE_FIELDS (TREE_TYPE (p2))), - true); - - same_bounds - = fold_build2_loc (loc, EQ_EXPR, result_type, p1_bounds, p2_bounds); - - /* P1_ARRAY == P2_ARRAY && (P1_ARRAY == NULL || P1_BOUNDS == P2_BOUNDS). */ - return build_binary_op (TRUTH_ANDIF_EXPR, result_type, same_array, - build_binary_op (TRUTH_ORIF_EXPR, result_type, - p1_array_is_null, same_bounds)); -} - -/* Compute the result of applying OP_CODE to LHS and RHS, where both are of - type TYPE. We know that TYPE is a modular type with a nonbinary - modulus. */ - -static tree -nonbinary_modular_operation (enum tree_code op_code, tree type, tree lhs, - tree rhs) -{ - tree modulus = TYPE_MODULUS (type); - unsigned int needed_precision = tree_floor_log2 (modulus) + 1; - unsigned int precision; - bool unsignedp = true; - tree op_type = type; - tree result; - - /* If this is an addition of a constant, convert it to a subtraction - of a constant since we can do that faster. */ - if (op_code == PLUS_EXPR && TREE_CODE (rhs) == INTEGER_CST) - { - rhs = fold_build2 (MINUS_EXPR, type, modulus, rhs); - op_code = MINUS_EXPR; - } - - /* For the logical operations, we only need PRECISION bits. For - addition and subtraction, we need one more and for multiplication we - need twice as many. But we never want to make a size smaller than - our size. */ - if (op_code == PLUS_EXPR || op_code == MINUS_EXPR) - needed_precision += 1; - else if (op_code == MULT_EXPR) - needed_precision *= 2; - - precision = MAX (needed_precision, TYPE_PRECISION (op_type)); - - /* Unsigned will do for everything but subtraction. */ - if (op_code == MINUS_EXPR) - unsignedp = false; - - /* If our type is the wrong signedness or isn't wide enough, make a new - type and convert both our operands to it. */ - if (TYPE_PRECISION (op_type) < precision - || TYPE_UNSIGNED (op_type) != unsignedp) - { - /* Copy the type so we ensure it can be modified to make it modular. */ - op_type = copy_type (gnat_type_for_size (precision, unsignedp)); - modulus = convert (op_type, modulus); - SET_TYPE_MODULUS (op_type, modulus); - TYPE_MODULAR_P (op_type) = 1; - lhs = convert (op_type, lhs); - rhs = convert (op_type, rhs); - } - - /* Do the operation, then we'll fix it up. */ - result = fold_build2 (op_code, op_type, lhs, rhs); - - /* For multiplication, we have no choice but to do a full modulus - operation. However, we want to do this in the narrowest - possible size. */ - if (op_code == MULT_EXPR) - { - /* Copy the type so we ensure it can be modified to make it modular. */ - tree div_type = copy_type (gnat_type_for_size (needed_precision, 1)); - modulus = convert (div_type, modulus); - SET_TYPE_MODULUS (div_type, modulus); - TYPE_MODULAR_P (div_type) = 1; - result = convert (op_type, - fold_build2 (TRUNC_MOD_EXPR, div_type, - convert (div_type, result), modulus)); - } - - /* For subtraction, add the modulus back if we are negative. */ - else if (op_code == MINUS_EXPR) - { - result = gnat_protect_expr (result); - result = fold_build3 (COND_EXPR, op_type, - fold_build2 (LT_EXPR, boolean_type_node, result, - build_int_cst (op_type, 0)), - fold_build2 (PLUS_EXPR, op_type, result, modulus), - result); - } - - /* For the other operations, subtract the modulus if we are >= it. */ - else - { - result = gnat_protect_expr (result); - result = fold_build3 (COND_EXPR, op_type, - fold_build2 (GE_EXPR, boolean_type_node, - result, modulus), - fold_build2 (MINUS_EXPR, op_type, - result, modulus), - result); - } - - return convert (type, result); -} - -/* This page contains routines that implement the Ada semantics with regard - to atomic objects. They are fully piggybacked on the middle-end support - for atomic loads and stores. - - *** Memory barriers and volatile objects *** - - We implement the weakened form of the C.6(16) clause that was introduced - in Ada 2012 (AI05-117). Earlier forms of this clause wouldn't have been - implementable without significant performance hits on modern platforms. - - We also take advantage of the requirements imposed on shared variables by - 9.10 (conditions for sequential actions) to have non-erroneous execution - and consider that C.6(16) and C.6(17) only prescribe an uniform order of - volatile updates with regard to sequential actions, i.e. with regard to - reads or updates of atomic objects. - - As such, an update of an atomic object by a task requires that all earlier - accesses to volatile objects have completed. Similarly, later accesses to - volatile objects cannot be reordered before the update of the atomic object. - So, memory barriers both before and after the atomic update are needed. - - For a read of an atomic object, to avoid seeing writes of volatile objects - by a task earlier than by the other tasks, a memory barrier is needed before - the atomic read. Finally, to avoid reordering later reads or updates of - volatile objects to before the atomic read, a barrier is needed after the - atomic read. - - So, memory barriers are needed before and after atomic reads and updates. - And, in order to simplify the implementation, we use full memory barriers - in all cases, i.e. we enforce sequential consistency for atomic accesses. */ - -/* Return the size of TYPE, which must be a positive power of 2. */ - -unsigned int -resolve_atomic_size (tree type) -{ - unsigned HOST_WIDE_INT size = tree_to_uhwi (TYPE_SIZE_UNIT (type)); - - if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16) - return size; - - /* We shouldn't reach here without having already detected that the size - isn't compatible with an atomic access. */ - gcc_assert (Serious_Errors_Detected); - - return 0; -} - -/* Build an atomic load for the underlying atomic object in SRC. SYNC is - true if the load requires synchronization. */ - -tree -build_atomic_load (tree src, bool sync) -{ - tree ptr_type - = build_pointer_type - (build_qualified_type (void_type_node, - TYPE_QUAL_ATOMIC | TYPE_QUAL_VOLATILE)); - tree mem_model - = build_int_cst (integer_type_node, - sync ? MEMMODEL_SEQ_CST : MEMMODEL_RELAXED); - tree orig_src = src; - tree t, addr, val; - unsigned int size; - int fncode; - - /* Remove conversions to get the address of the underlying object. */ - src = remove_conversions (src, false); - size = resolve_atomic_size (TREE_TYPE (src)); - if (size == 0) - return orig_src; - - fncode = (int) BUILT_IN_ATOMIC_LOAD_N + exact_log2 (size) + 1; - t = builtin_decl_implicit ((enum built_in_function) fncode); - - addr = build_unary_op (ADDR_EXPR, ptr_type, src); - val = build_call_expr (t, 2, addr, mem_model); - - /* First reinterpret the loaded bits in the original type of the load, - then convert to the expected result type. */ - t = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (src), val); - return convert (TREE_TYPE (orig_src), t); -} - -/* Build an atomic store from SRC to the underlying atomic object in DEST. - SYNC is true if the store requires synchronization. */ - -tree -build_atomic_store (tree dest, tree src, bool sync) -{ - tree ptr_type - = build_pointer_type - (build_qualified_type (void_type_node, - TYPE_QUAL_ATOMIC | TYPE_QUAL_VOLATILE)); - tree mem_model - = build_int_cst (integer_type_node, - sync ? MEMMODEL_SEQ_CST : MEMMODEL_RELAXED); - tree orig_dest = dest; - tree t, int_type, addr; - unsigned int size; - int fncode; - - /* Remove conversions to get the address of the underlying object. */ - dest = remove_conversions (dest, false); - size = resolve_atomic_size (TREE_TYPE (dest)); - if (size == 0) - return build_binary_op (MODIFY_EXPR, NULL_TREE, orig_dest, src); - - fncode = (int) BUILT_IN_ATOMIC_STORE_N + exact_log2 (size) + 1; - t = builtin_decl_implicit ((enum built_in_function) fncode); - int_type = gnat_type_for_size (BITS_PER_UNIT * size, 1); - - /* First convert the bits to be stored to the original type of the store, - then reinterpret them in the effective type. But if the original type - is a padded type with the same size, convert to the inner type instead, - as we don't want to artificially introduce a CONSTRUCTOR here. */ - if (TYPE_IS_PADDING_P (TREE_TYPE (dest)) - && TYPE_SIZE (TREE_TYPE (dest)) - == TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (dest))))) - src = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (dest))), src); - else - src = convert (TREE_TYPE (dest), src); - src = fold_build1 (VIEW_CONVERT_EXPR, int_type, src); - addr = build_unary_op (ADDR_EXPR, ptr_type, dest); - - return build_call_expr (t, 3, addr, src, mem_model); -} - -/* Build a load-modify-store sequence from SRC to DEST. GNAT_NODE is used for - the location of the sequence. Note that, even though the load and the store - are both atomic, the sequence itself is not atomic. */ - -tree -build_load_modify_store (tree dest, tree src, Node_Id gnat_node) -{ - /* We will be modifying DEST below so we build a copy. */ - dest = copy_node (dest); - tree ref = dest; - - while (handled_component_p (ref)) - { - /* The load should already have been generated during the translation - of the GNAT destination tree; find it out in the GNU tree. */ - if (TREE_CODE (TREE_OPERAND (ref, 0)) == VIEW_CONVERT_EXPR) - { - tree op = TREE_OPERAND (TREE_OPERAND (ref, 0), 0); - if (TREE_CODE (op) == CALL_EXPR && call_is_atomic_load (op)) - { - tree type = TREE_TYPE (TREE_OPERAND (ref, 0)); - tree t = CALL_EXPR_ARG (op, 0); - tree obj, temp, stmt; - - /* Find out the loaded object. */ - if (TREE_CODE (t) == NOP_EXPR) - t = TREE_OPERAND (t, 0); - if (TREE_CODE (t) == ADDR_EXPR) - obj = TREE_OPERAND (t, 0); - else - obj = build1 (INDIRECT_REF, type, t); - - /* Drop atomic and volatile qualifiers for the temporary. */ - type = TYPE_MAIN_VARIANT (type); - - /* And drop BLKmode, if need be, to put it into a register. */ - if (TYPE_MODE (type) == BLKmode) - { - unsigned int size = tree_to_uhwi (TYPE_SIZE (type)); - type = copy_type (type); - machine_mode mode = int_mode_for_size (size, 0).else_blk (); - SET_TYPE_MODE (type, mode); - } - - /* Create the temporary by inserting a SAVE_EXPR. */ - temp = build1 (SAVE_EXPR, type, - build1 (VIEW_CONVERT_EXPR, type, op)); - TREE_OPERAND (ref, 0) = temp; - - start_stmt_group (); - - /* Build the modify of the temporary. */ - stmt = build_binary_op (MODIFY_EXPR, NULL_TREE, dest, src); - add_stmt_with_node (stmt, gnat_node); - - /* Build the store to the object. */ - stmt = build_atomic_store (obj, temp, false); - add_stmt_with_node (stmt, gnat_node); - - return end_stmt_group (); - } - } - - TREE_OPERAND (ref, 0) = copy_node (TREE_OPERAND (ref, 0)); - ref = TREE_OPERAND (ref, 0); - } - - /* Something went wrong earlier if we have not found the atomic load. */ - gcc_unreachable (); -} - -/* Make a binary operation of kind OP_CODE. RESULT_TYPE is the type - desired for the result. Usually the operation is to be performed - in that type. For INIT_EXPR and MODIFY_EXPR, RESULT_TYPE must be - NULL_TREE. For ARRAY_REF, RESULT_TYPE may be NULL_TREE, in which - case the type to be used will be derived from the operands. - Don't fold the result if NO_FOLD is true. - - This function is very much unlike the ones for C and C++ since we - have already done any type conversion and matching required. All we - have to do here is validate the work done by SEM and handle subtypes. */ - -tree -build_binary_op (enum tree_code op_code, tree result_type, - tree left_operand, tree right_operand, - bool no_fold) -{ - tree left_type = TREE_TYPE (left_operand); - tree right_type = TREE_TYPE (right_operand); - tree left_base_type = get_base_type (left_type); - tree right_base_type = get_base_type (right_type); - tree operation_type = result_type; - tree best_type = NULL_TREE; - tree modulus, result; - bool has_side_effects = false; - - if (operation_type - && TREE_CODE (operation_type) == RECORD_TYPE - && TYPE_JUSTIFIED_MODULAR_P (operation_type)) - operation_type = TREE_TYPE (TYPE_FIELDS (operation_type)); - - if (operation_type && TYPE_IS_EXTRA_SUBTYPE_P (operation_type)) - operation_type = get_base_type (operation_type); - - modulus = (operation_type - && TREE_CODE (operation_type) == INTEGER_TYPE - && TYPE_MODULAR_P (operation_type) - ? TYPE_MODULUS (operation_type) : NULL_TREE); - - switch (op_code) - { - case INIT_EXPR: - case MODIFY_EXPR: - gcc_checking_assert (!result_type); - - /* If there were integral or pointer conversions on the LHS, remove - them; we'll be putting them back below if needed. Likewise for - conversions between record types, except for justified modular types. - But don't do this if the right operand is not BLKmode (for packed - arrays) unless we are not changing the mode. */ - while ((CONVERT_EXPR_P (left_operand) - || TREE_CODE (left_operand) == VIEW_CONVERT_EXPR) - && (((INTEGRAL_TYPE_P (left_type) - || POINTER_TYPE_P (left_type)) - && (INTEGRAL_TYPE_P (operand_type (left_operand)) - || POINTER_TYPE_P (operand_type (left_operand)))) - || (TREE_CODE (left_type) == RECORD_TYPE - && !TYPE_JUSTIFIED_MODULAR_P (left_type) - && TREE_CODE (operand_type (left_operand)) == RECORD_TYPE - && (TYPE_MODE (right_type) == BLKmode - || TYPE_MODE (left_type) - == TYPE_MODE (operand_type (left_operand)))))) - { - left_operand = TREE_OPERAND (left_operand, 0); - left_type = TREE_TYPE (left_operand); - } - - /* If a class-wide type may be involved, force use of the RHS type. */ - if ((TREE_CODE (right_type) == RECORD_TYPE - || TREE_CODE (right_type) == UNION_TYPE) - && TYPE_ALIGN_OK (right_type)) - operation_type = right_type; - - /* If we are copying between padded objects with compatible types, use - the padded view of the objects, this is very likely more efficient. - Likewise for a padded object that is assigned a constructor, if we - can convert the constructor to the inner type, to avoid putting a - VIEW_CONVERT_EXPR on the LHS. But don't do so if we wouldn't have - actually copied anything. */ - else if (TYPE_IS_PADDING_P (left_type) - && TREE_CONSTANT (TYPE_SIZE (left_type)) - && ((TREE_CODE (right_operand) == COMPONENT_REF - && TYPE_MAIN_VARIANT (left_type) - == TYPE_MAIN_VARIANT (operand_type (right_operand))) - || (TREE_CODE (right_operand) == CONSTRUCTOR - && !CONTAINS_PLACEHOLDER_P - (DECL_SIZE (TYPE_FIELDS (left_type))))) - && !integer_zerop (TYPE_SIZE (right_type))) - { - /* We make an exception for a BLKmode type padding a non-BLKmode - inner type and do the conversion of the LHS right away, since - unchecked_convert wouldn't do it properly. */ - if (TYPE_MODE (left_type) == BLKmode - && TYPE_MODE (right_type) != BLKmode - && TREE_CODE (right_operand) != CONSTRUCTOR) - { - operation_type = right_type; - left_operand = convert (operation_type, left_operand); - left_type = operation_type; - } - else - operation_type = left_type; - } - - /* If we have a call to a function that returns with variable size, use - the RHS type in case we want to use the return slot optimization. */ - else if (TREE_CODE (right_operand) == CALL_EXPR - && return_type_with_variable_size_p (right_type)) - operation_type = right_type; - - /* Find the best type to use for copying between aggregate types. */ - else if (((TREE_CODE (left_type) == ARRAY_TYPE - && TREE_CODE (right_type) == ARRAY_TYPE) - || (TREE_CODE (left_type) == RECORD_TYPE - && TREE_CODE (right_type) == RECORD_TYPE)) - && (best_type = find_common_type (left_type, right_type))) - operation_type = best_type; - - /* Otherwise use the LHS type. */ - else - operation_type = left_type; - - /* Ensure everything on the LHS is valid. If we have a field reference, - strip anything that get_inner_reference can handle. Then remove any - conversions between types having the same code and mode. And mark - VIEW_CONVERT_EXPRs with TREE_ADDRESSABLE. When done, we must have - either an INDIRECT_REF, a NULL_EXPR, a SAVE_EXPR or a DECL node. */ - result = left_operand; - while (true) - { - tree restype = TREE_TYPE (result); - - if (TREE_CODE (result) == COMPONENT_REF - || TREE_CODE (result) == ARRAY_REF - || TREE_CODE (result) == ARRAY_RANGE_REF) - while (handled_component_p (result)) - result = TREE_OPERAND (result, 0); - - else if (TREE_CODE (result) == REALPART_EXPR - || TREE_CODE (result) == IMAGPART_EXPR - || (CONVERT_EXPR_P (result) - && (((TREE_CODE (restype) - == TREE_CODE (operand_type (result)) - && TYPE_MODE (restype) - == TYPE_MODE (operand_type (result)))) - || TYPE_ALIGN_OK (restype)))) - result = TREE_OPERAND (result, 0); - - else if (TREE_CODE (result) == VIEW_CONVERT_EXPR) - { - TREE_ADDRESSABLE (result) = 1; - result = TREE_OPERAND (result, 0); - } - - else - break; - } - - gcc_assert (TREE_CODE (result) == INDIRECT_REF - || TREE_CODE (result) == NULL_EXPR - || TREE_CODE (result) == SAVE_EXPR - || DECL_P (result)); - - /* Convert the right operand to the operation type unless it is - either already of the correct type or if the type involves a - placeholder, since the RHS may not have the same record type. */ - if (operation_type != right_type - && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (operation_type))) - { - right_operand = convert (operation_type, right_operand); - right_type = operation_type; - } - - /* If the left operand is not of the same type as the operation - type, wrap it up in a VIEW_CONVERT_EXPR. */ - if (left_type != operation_type) - left_operand = unchecked_convert (operation_type, left_operand, false); - - has_side_effects = true; - modulus = NULL_TREE; - break; - - case ARRAY_REF: - if (!operation_type) - operation_type = TREE_TYPE (left_type); - - /* ... fall through ... */ - - case ARRAY_RANGE_REF: - /* First look through conversion between type variants. Note that - this changes neither the operation type nor the type domain. */ - if (TREE_CODE (left_operand) == VIEW_CONVERT_EXPR - && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (left_operand, 0))) - == TYPE_MAIN_VARIANT (left_type)) - { - left_operand = TREE_OPERAND (left_operand, 0); - left_type = TREE_TYPE (left_operand); - } - - /* For a range, make sure the element type is consistent. */ - if (op_code == ARRAY_RANGE_REF - && TREE_TYPE (operation_type) != TREE_TYPE (left_type)) - { - operation_type - = build_nonshared_array_type (TREE_TYPE (left_type), - TYPE_DOMAIN (operation_type)); - /* Declare it now since it will never be declared otherwise. This - is necessary to ensure that its subtrees are properly marked. */ - create_type_decl (TYPE_NAME (operation_type), operation_type, true, - false, Empty); - } - - /* Then convert the right operand to its base type. This will prevent - unneeded sign conversions when sizetype is wider than integer. */ - right_operand = convert (right_base_type, right_operand); - right_operand = convert_to_index_type (right_operand); - modulus = NULL_TREE; - break; - - case TRUTH_ANDIF_EXPR: - case TRUTH_ORIF_EXPR: - case TRUTH_AND_EXPR: - case TRUTH_OR_EXPR: - case TRUTH_XOR_EXPR: - gcc_checking_assert - (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE); - operation_type = left_base_type; - left_operand = convert (operation_type, left_operand); - right_operand = convert (operation_type, right_operand); - break; - - case GE_EXPR: - case LE_EXPR: - case GT_EXPR: - case LT_EXPR: - case EQ_EXPR: - case NE_EXPR: - gcc_checking_assert - (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE); - /* If either operand is a NULL_EXPR, just return a new one. */ - if (TREE_CODE (left_operand) == NULL_EXPR) - return build2 (op_code, result_type, - build1 (NULL_EXPR, integer_type_node, - TREE_OPERAND (left_operand, 0)), - integer_zero_node); - - else if (TREE_CODE (right_operand) == NULL_EXPR) - return build2 (op_code, result_type, - build1 (NULL_EXPR, integer_type_node, - TREE_OPERAND (right_operand, 0)), - integer_zero_node); - - /* If either object is a justified modular types, get the - fields from within. */ - if (TREE_CODE (left_type) == RECORD_TYPE - && TYPE_JUSTIFIED_MODULAR_P (left_type)) - { - left_operand = convert (TREE_TYPE (TYPE_FIELDS (left_type)), - left_operand); - left_type = TREE_TYPE (left_operand); - left_base_type = get_base_type (left_type); - } - - if (TREE_CODE (right_type) == RECORD_TYPE - && TYPE_JUSTIFIED_MODULAR_P (right_type)) - { - right_operand = convert (TREE_TYPE (TYPE_FIELDS (right_type)), - right_operand); - right_type = TREE_TYPE (right_operand); - right_base_type = get_base_type (right_type); - } - - /* If both objects are arrays, compare them specially. */ - if ((TREE_CODE (left_type) == ARRAY_TYPE - || (TREE_CODE (left_type) == INTEGER_TYPE - && TYPE_HAS_ACTUAL_BOUNDS_P (left_type))) - && (TREE_CODE (right_type) == ARRAY_TYPE - || (TREE_CODE (right_type) == INTEGER_TYPE - && TYPE_HAS_ACTUAL_BOUNDS_P (right_type)))) - { - result = compare_arrays (input_location, - result_type, left_operand, right_operand); - if (op_code == NE_EXPR) - result = invert_truthvalue_loc (EXPR_LOCATION (result), result); - else - gcc_assert (op_code == EQ_EXPR); - - return result; - } - - /* Otherwise, the base types must be the same, unless they are both (fat) - pointer types or record types. In the latter case, use the best type - and convert both operands to that type. */ - if (left_base_type != right_base_type) - { - if (TYPE_IS_FAT_POINTER_P (left_base_type) - && TYPE_IS_FAT_POINTER_P (right_base_type)) - { - gcc_assert (TYPE_MAIN_VARIANT (left_base_type) - == TYPE_MAIN_VARIANT (right_base_type)); - best_type = left_base_type; - } - - else if (POINTER_TYPE_P (left_base_type) - && POINTER_TYPE_P (right_base_type)) - { - /* Anonymous access types in Ada 2005 can point to different - members of a tagged type hierarchy. */ - gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (left_base_type)) - == TYPE_MAIN_VARIANT (TREE_TYPE (right_base_type)) - || (TYPE_ALIGN_OK (TREE_TYPE (left_base_type)) - && TYPE_ALIGN_OK (TREE_TYPE (right_base_type)))); - best_type = left_base_type; - } - - else if (TREE_CODE (left_base_type) == RECORD_TYPE - && TREE_CODE (right_base_type) == RECORD_TYPE) - { - /* The only way this is permitted is if both types have the same - name. In that case, one of them must not be self-referential. - Use it as the best type. Even better with a fixed size. */ - gcc_assert (TYPE_NAME (left_base_type) - && TYPE_NAME (left_base_type) - == TYPE_NAME (right_base_type)); - - if (TREE_CONSTANT (TYPE_SIZE (left_base_type))) - best_type = left_base_type; - else if (TREE_CONSTANT (TYPE_SIZE (right_base_type))) - best_type = right_base_type; - else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (left_base_type))) - best_type = left_base_type; - else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (right_base_type))) - best_type = right_base_type; - else - gcc_unreachable (); - } - - else - gcc_unreachable (); - - left_operand = convert (best_type, left_operand); - right_operand = convert (best_type, right_operand); - } - else - { - left_operand = convert (left_base_type, left_operand); - right_operand = convert (right_base_type, right_operand); - } - - /* If both objects are fat pointers, compare them specially. */ - if (TYPE_IS_FAT_POINTER_P (left_base_type)) - { - result - = compare_fat_pointers (input_location, - result_type, left_operand, right_operand); - if (op_code == NE_EXPR) - result = invert_truthvalue_loc (EXPR_LOCATION (result), result); - else - gcc_assert (op_code == EQ_EXPR); - - return result; - } - - modulus = NULL_TREE; - break; - - case LSHIFT_EXPR: - case RSHIFT_EXPR: - case LROTATE_EXPR: - case RROTATE_EXPR: - /* The RHS of a shift can be any type. Also, ignore any modulus - (we used to abort, but this is needed for unchecked conversion - to modular types). Otherwise, processing is the same as normal. */ - gcc_assert (operation_type == left_base_type); - modulus = NULL_TREE; - left_operand = convert (operation_type, left_operand); - break; - - case BIT_AND_EXPR: - case BIT_IOR_EXPR: - case BIT_XOR_EXPR: - /* For binary modulus, if the inputs are in range, so are the - outputs. */ - if (modulus && integer_pow2p (modulus)) - modulus = NULL_TREE; - goto common; - - case COMPLEX_EXPR: - gcc_assert (TREE_TYPE (result_type) == left_base_type - && TREE_TYPE (result_type) == right_base_type); - left_operand = convert (left_base_type, left_operand); - right_operand = convert (right_base_type, right_operand); - break; - - case TRUNC_DIV_EXPR: case TRUNC_MOD_EXPR: - case CEIL_DIV_EXPR: case CEIL_MOD_EXPR: - case FLOOR_DIV_EXPR: case FLOOR_MOD_EXPR: - case ROUND_DIV_EXPR: case ROUND_MOD_EXPR: - /* These always produce results lower than either operand. */ - modulus = NULL_TREE; - goto common; - - case POINTER_PLUS_EXPR: - gcc_assert (operation_type == left_base_type - && sizetype == right_base_type); - left_operand = convert (operation_type, left_operand); - right_operand = convert (sizetype, right_operand); - break; - - case PLUS_NOMOD_EXPR: - case MINUS_NOMOD_EXPR: - if (op_code == PLUS_NOMOD_EXPR) - op_code = PLUS_EXPR; - else - op_code = MINUS_EXPR; - modulus = NULL_TREE; - - /* ... fall through ... */ - - case PLUS_EXPR: - case MINUS_EXPR: - /* Avoid doing arithmetics in ENUMERAL_TYPE or BOOLEAN_TYPE like the - other compilers. Contrary to C, Ada doesn't allow arithmetics in - these types but can generate addition/subtraction for Succ/Pred. */ - if (operation_type - && (TREE_CODE (operation_type) == ENUMERAL_TYPE - || TREE_CODE (operation_type) == BOOLEAN_TYPE)) - operation_type = left_base_type = right_base_type - = gnat_type_for_mode (TYPE_MODE (operation_type), - TYPE_UNSIGNED (operation_type)); - - /* ... fall through ... */ - - default: - common: - /* The result type should be the same as the base types of the - both operands (and they should be the same). Convert - everything to the result type. */ - - gcc_assert (operation_type == left_base_type - && left_base_type == right_base_type); - left_operand = convert (operation_type, left_operand); - right_operand = convert (operation_type, right_operand); - } - - if (modulus && !integer_pow2p (modulus)) - { - result = nonbinary_modular_operation (op_code, operation_type, - left_operand, right_operand); - modulus = NULL_TREE; - } - /* If either operand is a NULL_EXPR, just return a new one. */ - else if (TREE_CODE (left_operand) == NULL_EXPR) - return build1 (NULL_EXPR, operation_type, TREE_OPERAND (left_operand, 0)); - else if (TREE_CODE (right_operand) == NULL_EXPR) - return build1 (NULL_EXPR, operation_type, TREE_OPERAND (right_operand, 0)); - else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF) - { - result = build4 (op_code, operation_type, left_operand, right_operand, - NULL_TREE, NULL_TREE); - if (!no_fold) - result = fold (result); - } - else if (op_code == INIT_EXPR || op_code == MODIFY_EXPR) - result = build2 (op_code, void_type_node, left_operand, right_operand); - else if (no_fold) - result = build2 (op_code, operation_type, left_operand, right_operand); - else - result - = fold_build2 (op_code, operation_type, left_operand, right_operand); - - if (TREE_CONSTANT (result)) - ; - else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF) - { - if (TYPE_VOLATILE (operation_type)) - TREE_THIS_VOLATILE (result) = 1; - } - else if (TREE_CONSTANT (left_operand) && TREE_CONSTANT (right_operand)) - TREE_CONSTANT (result) = 1; - - if (has_side_effects) - TREE_SIDE_EFFECTS (result) = 1; - - /* If we are working with modular types, perform the MOD operation - if something above hasn't eliminated the need for it. */ - if (modulus) - { - modulus = convert (operation_type, modulus); - if (no_fold) - result = build2 (FLOOR_MOD_EXPR, operation_type, result, modulus); - else - result = fold_build2 (FLOOR_MOD_EXPR, operation_type, result, modulus); - } - - if (result_type && result_type != operation_type) - result = convert (result_type, result); - - return result; -} - -/* Similar, but for unary operations. */ - -tree -build_unary_op (enum tree_code op_code, tree result_type, tree operand) -{ - tree type = TREE_TYPE (operand); - tree base_type = get_base_type (type); - tree operation_type = result_type; - tree result; - - if (operation_type - && TREE_CODE (operation_type) == RECORD_TYPE - && TYPE_JUSTIFIED_MODULAR_P (operation_type)) - operation_type = TREE_TYPE (TYPE_FIELDS (operation_type)); - - if (operation_type - && TREE_CODE (operation_type) == INTEGER_TYPE - && TYPE_EXTRA_SUBTYPE_P (operation_type)) - operation_type = get_base_type (operation_type); - - switch (op_code) - { - case REALPART_EXPR: - case IMAGPART_EXPR: - if (!operation_type) - result_type = operation_type = TREE_TYPE (type); - else - gcc_assert (result_type == TREE_TYPE (type)); - - result = fold_build1 (op_code, operation_type, operand); - break; - - case TRUTH_NOT_EXPR: - gcc_checking_assert - (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE); - result = invert_truthvalue_loc (EXPR_LOCATION (operand), operand); - /* When not optimizing, fold the result as invert_truthvalue_loc - doesn't fold the result of comparisons. This is intended to undo - the trick used for boolean rvalues in gnat_to_gnu. */ - if (!optimize) - result = fold (result); - break; - - case ATTR_ADDR_EXPR: - case ADDR_EXPR: - switch (TREE_CODE (operand)) - { - case INDIRECT_REF: - case UNCONSTRAINED_ARRAY_REF: - result = TREE_OPERAND (operand, 0); - - /* Make sure the type here is a pointer, not a reference. - GCC wants pointer types for function addresses. */ - if (!result_type) - result_type = build_pointer_type (type); - - /* If the underlying object can alias everything, propagate the - property since we are effectively retrieving the object. */ - if (POINTER_TYPE_P (TREE_TYPE (result)) - && TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (result))) - { - if (TREE_CODE (result_type) == POINTER_TYPE - && !TYPE_REF_CAN_ALIAS_ALL (result_type)) - result_type - = build_pointer_type_for_mode (TREE_TYPE (result_type), - TYPE_MODE (result_type), - true); - else if (TREE_CODE (result_type) == REFERENCE_TYPE - && !TYPE_REF_CAN_ALIAS_ALL (result_type)) - result_type - = build_reference_type_for_mode (TREE_TYPE (result_type), - TYPE_MODE (result_type), - true); - } - break; - - case NULL_EXPR: - result = operand; - TREE_TYPE (result) = type = build_pointer_type (type); - break; - - case COMPOUND_EXPR: - /* Fold a compound expression if it has unconstrained array type - since the middle-end cannot handle it. But we don't it in the - general case because it may introduce aliasing issues if the - first operand is an indirect assignment and the second operand - the corresponding address, e.g. for an allocator. However do - it for a return value to expose it for later recognition. */ - if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE - || (TREE_CODE (TREE_OPERAND (operand, 1)) == VAR_DECL - && DECL_RETURN_VALUE_P (TREE_OPERAND (operand, 1)))) - { - result = build_unary_op (ADDR_EXPR, result_type, - TREE_OPERAND (operand, 1)); - result = build2 (COMPOUND_EXPR, TREE_TYPE (result), - TREE_OPERAND (operand, 0), result); - break; - } - goto common; - - case ARRAY_REF: - case ARRAY_RANGE_REF: - case COMPONENT_REF: - case BIT_FIELD_REF: - /* If this is for 'Address, find the address of the prefix and add - the offset to the field. Otherwise, do this the normal way. */ - if (op_code == ATTR_ADDR_EXPR) - { - poly_int64 bitsize; - poly_int64 bitpos; - tree offset, inner; - machine_mode mode; - int unsignedp, reversep, volatilep; - - inner = get_inner_reference (operand, &bitsize, &bitpos, &offset, - &mode, &unsignedp, &reversep, - &volatilep); - - /* If INNER is a padding type whose field has a self-referential - size, convert to that inner type. We know the offset is zero - and we need to have that type visible. */ - if (type_is_padding_self_referential (TREE_TYPE (inner))) - inner = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (inner))), - inner); - - /* Compute the offset as a byte offset from INNER. */ - if (!offset) - offset = size_zero_node; - - offset - = size_binop (PLUS_EXPR, offset, - size_int (bits_to_bytes_round_down (bitpos))); - - /* Take the address of INNER, convert it to a pointer to our type - and add the offset. */ - inner = build_unary_op (ADDR_EXPR, - build_pointer_type (TREE_TYPE (operand)), - inner); - result = build_binary_op (POINTER_PLUS_EXPR, TREE_TYPE (inner), - inner, offset); - break; - } - goto common; - - case CONSTRUCTOR: - /* If this is just a constructor for a padded record, we can - just take the address of the single field and convert it to - a pointer to our type. */ - if (TYPE_IS_PADDING_P (type)) - { - result - = build_unary_op (ADDR_EXPR, - build_pointer_type (TREE_TYPE (operand)), - CONSTRUCTOR_ELT (operand, 0)->value); - break; - } - goto common; - - case NOP_EXPR: - if (AGGREGATE_TYPE_P (type) - && AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (operand, 0)))) - return build_unary_op (ADDR_EXPR, result_type, - TREE_OPERAND (operand, 0)); - - /* ... fallthru ... */ - - case VIEW_CONVERT_EXPR: - /* If this just a variant conversion or if the conversion doesn't - change the mode, get the result type from this type and go down. - This is needed for conversions of CONST_DECLs, to eventually get - to the address of their CORRESPONDING_VARs. */ - if ((TYPE_MAIN_VARIANT (type) - == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (operand, 0)))) - || (TYPE_MODE (type) != BLKmode - && (TYPE_MODE (type) - == TYPE_MODE (TREE_TYPE (TREE_OPERAND (operand, 0)))))) - return build_unary_op (ADDR_EXPR, - (result_type ? result_type - : build_pointer_type (type)), - TREE_OPERAND (operand, 0)); - goto common; - - case CONST_DECL: - operand = DECL_CONST_CORRESPONDING_VAR (operand); - - /* ... fall through ... */ - - default: - common: - - /* If we are taking the address of a padded record whose field - contains a template, take the address of the field. */ - if (TYPE_IS_PADDING_P (type) - && TREE_CODE (TREE_TYPE (TYPE_FIELDS (type))) == RECORD_TYPE - && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (TYPE_FIELDS (type)))) - { - type = TREE_TYPE (TYPE_FIELDS (type)); - operand = convert (type, operand); - } - - gnat_mark_addressable (operand); - result = build_fold_addr_expr (operand); - } - - if (TREE_CONSTANT (operand) || staticp (operand)) - TREE_CONSTANT (result) = 1; - - break; - - case INDIRECT_REF: - { - tree t = remove_conversions (operand, false); - bool can_never_be_null = DECL_P (t) && DECL_CAN_NEVER_BE_NULL_P (t); - - /* If TYPE is a thin pointer, either first retrieve the base if this - is an expression with an offset built for the initialization of an - object with an unconstrained nominal subtype, or else convert to - the fat pointer. */ - if (TYPE_IS_THIN_POINTER_P (type)) - { - tree rec_type = TREE_TYPE (type); - - if (TREE_CODE (operand) == POINTER_PLUS_EXPR - && TREE_OPERAND (operand, 1) - == byte_position (DECL_CHAIN (TYPE_FIELDS (rec_type))) - && TREE_CODE (TREE_OPERAND (operand, 0)) == NOP_EXPR) - { - operand = TREE_OPERAND (TREE_OPERAND (operand, 0), 0); - type = TREE_TYPE (operand); - } - else if (TYPE_UNCONSTRAINED_ARRAY (rec_type)) - { - operand - = convert (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (rec_type)), - operand); - type = TREE_TYPE (operand); - } - } - - /* If we want to refer to an unconstrained array, use the appropriate - expression. But this will never survive down to the back-end. */ - if (TYPE_IS_FAT_POINTER_P (type)) - { - result = build1 (UNCONSTRAINED_ARRAY_REF, - TYPE_UNCONSTRAINED_ARRAY (type), operand); - TREE_READONLY (result) - = TYPE_READONLY (TYPE_UNCONSTRAINED_ARRAY (type)); - } - - /* If we are dereferencing an ADDR_EXPR, return its operand. */ - else if (TREE_CODE (operand) == ADDR_EXPR) - result = TREE_OPERAND (operand, 0); - - /* Otherwise, build and fold the indirect reference. */ - else - { - result = build_fold_indirect_ref (operand); - TREE_READONLY (result) = TYPE_READONLY (TREE_TYPE (type)); - } - - if (!TYPE_IS_FAT_POINTER_P (type) && TYPE_VOLATILE (TREE_TYPE (type))) - { - TREE_SIDE_EFFECTS (result) = 1; - if (TREE_CODE (result) == INDIRECT_REF) - TREE_THIS_VOLATILE (result) = TYPE_VOLATILE (TREE_TYPE (result)); - } - - if ((TREE_CODE (result) == INDIRECT_REF - || TREE_CODE (result) == UNCONSTRAINED_ARRAY_REF) - && can_never_be_null) - TREE_THIS_NOTRAP (result) = 1; - - break; - } - - case NEGATE_EXPR: - case BIT_NOT_EXPR: - { - tree modulus = ((operation_type - && TREE_CODE (operation_type) == INTEGER_TYPE - && TYPE_MODULAR_P (operation_type)) - ? TYPE_MODULUS (operation_type) : NULL_TREE); - int mod_pow2 = modulus && integer_pow2p (modulus); - - /* If this is a modular type, there are various possibilities - depending on the operation and whether the modulus is a - power of two or not. */ - - if (modulus) - { - gcc_assert (operation_type == base_type); - operand = convert (operation_type, operand); - - /* The fastest in the negate case for binary modulus is - the straightforward code; the TRUNC_MOD_EXPR below - is an AND operation. */ - if (op_code == NEGATE_EXPR && mod_pow2) - result = fold_build2 (TRUNC_MOD_EXPR, operation_type, - fold_build1 (NEGATE_EXPR, operation_type, - operand), - modulus); - - /* For nonbinary negate case, return zero for zero operand, - else return the modulus minus the operand. If the modulus - is a power of two minus one, we can do the subtraction - as an XOR since it is equivalent and faster on most machines. */ - else if (op_code == NEGATE_EXPR && !mod_pow2) - { - if (integer_pow2p (fold_build2 (PLUS_EXPR, operation_type, - modulus, - build_int_cst (operation_type, - 1)))) - result = fold_build2 (BIT_XOR_EXPR, operation_type, - operand, modulus); - else - result = fold_build2 (MINUS_EXPR, operation_type, - modulus, operand); - - result = fold_build3 (COND_EXPR, operation_type, - fold_build2 (NE_EXPR, - boolean_type_node, - operand, - build_int_cst - (operation_type, 0)), - result, operand); - } - else - { - /* For the NOT cases, we need a constant equal to - the modulus minus one. For a binary modulus, we - XOR against the constant and subtract the operand from - that constant for nonbinary modulus. */ - - tree cnst = fold_build2 (MINUS_EXPR, operation_type, modulus, - build_int_cst (operation_type, 1)); - - if (mod_pow2) - result = fold_build2 (BIT_XOR_EXPR, operation_type, - operand, cnst); - else - result = fold_build2 (MINUS_EXPR, operation_type, - cnst, operand); - } - - break; - } - } - - /* ... fall through ... */ - - default: - gcc_assert (operation_type == base_type); - result = fold_build1 (op_code, operation_type, - convert (operation_type, operand)); - } - - if (result_type && TREE_TYPE (result) != result_type) - result = convert (result_type, result); - - return result; -} - -/* Similar, but for COND_EXPR. */ - -tree -build_cond_expr (tree result_type, tree condition_operand, - tree true_operand, tree false_operand) -{ - bool addr_p = false; - tree result; - - /* The front-end verified that result, true and false operands have - same base type. Convert everything to the result type. */ - true_operand = convert (result_type, true_operand); - false_operand = convert (result_type, false_operand); - - /* If the result type is unconstrained, take the address of the operands and - then dereference the result. Likewise if the result type is passed by - reference, because creating a temporary of this type is not allowed. */ - if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE - || TYPE_IS_BY_REFERENCE_P (result_type) - || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type))) - { - result_type = build_pointer_type (result_type); - true_operand = build_unary_op (ADDR_EXPR, result_type, true_operand); - false_operand = build_unary_op (ADDR_EXPR, result_type, false_operand); - addr_p = true; - } - - result = fold_build3 (COND_EXPR, result_type, condition_operand, - true_operand, false_operand); - - /* If we have a common SAVE_EXPR (possibly surrounded by arithmetics) - in both arms, make sure it gets evaluated by moving it ahead of the - conditional expression. This is necessary because it is evaluated - in only one place at run time and would otherwise be uninitialized - in one of the arms. */ - true_operand = skip_simple_arithmetic (true_operand); - false_operand = skip_simple_arithmetic (false_operand); - - if (true_operand == false_operand && TREE_CODE (true_operand) == SAVE_EXPR) - result = build2 (COMPOUND_EXPR, result_type, true_operand, result); - - if (addr_p) - result = build_unary_op (INDIRECT_REF, NULL_TREE, result); - - return result; -} - -/* Similar, but for COMPOUND_EXPR. */ - -tree -build_compound_expr (tree result_type, tree stmt_operand, tree expr_operand) -{ - bool addr_p = false; - tree result; - - /* If the result type is unconstrained, take the address of the operand and - then dereference the result. Likewise if the result type is passed by - reference, but this is natively handled in the gimplifier. */ - if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE - || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type))) - { - result_type = build_pointer_type (result_type); - expr_operand = build_unary_op (ADDR_EXPR, result_type, expr_operand); - addr_p = true; - } - - result = fold_build2 (COMPOUND_EXPR, result_type, stmt_operand, - expr_operand); - - if (addr_p) - result = build_unary_op (INDIRECT_REF, NULL_TREE, result); - - return result; -} - -/* Conveniently construct a function call expression. FNDECL names the - function to be called, N is the number of arguments, and the "..." - parameters are the argument expressions. Unlike build_call_expr - this doesn't fold the call, hence it will always return a CALL_EXPR. */ - -tree -build_call_n_expr (tree fndecl, int n, ...) -{ - va_list ap; - tree fntype = TREE_TYPE (fndecl); - tree fn = build1 (ADDR_EXPR, build_pointer_type (fntype), fndecl); - - va_start (ap, n); - fn = build_call_valist (TREE_TYPE (fntype), fn, n, ap); - va_end (ap); - return fn; -} - -/* Build a goto to LABEL for a raise, with an optional call to Local_Raise. - MSG gives the exception's identity for the call to Local_Raise, if any. */ - -static tree -build_goto_raise (Entity_Id gnat_label, int msg) -{ - tree gnu_label = gnat_to_gnu_entity (gnat_label, NULL_TREE, false); - tree gnu_result = build1 (GOTO_EXPR, void_type_node, gnu_label); - Entity_Id local_raise = Get_Local_Raise_Call_Entity (); - - /* If Local_Raise is present, build Local_Raise (Exception'Identity). */ - if (Present (local_raise)) - { - tree gnu_local_raise - = gnat_to_gnu_entity (local_raise, NULL_TREE, false); - tree gnu_exception_entity - = gnat_to_gnu_entity (Get_RT_Exception_Entity (msg), NULL_TREE, false); - tree gnu_call - = build_call_n_expr (gnu_local_raise, 1, - build_unary_op (ADDR_EXPR, NULL_TREE, - gnu_exception_entity)); - gnu_result - = build2 (COMPOUND_EXPR, void_type_node, gnu_call, gnu_result); - } - - TREE_USED (gnu_label) = 1; - return gnu_result; -} - -/* Expand the SLOC of GNAT_NODE, if present, into tree location information - pointed to by FILENAME, LINE and COL. Fall back to the current location - if GNAT_NODE is absent or has no SLOC. */ - -static void -expand_sloc (Node_Id gnat_node, tree *filename, tree *line, tree *col) -{ - const char *str; - int line_number, column_number; - - if (Debug_Flag_NN || Exception_Locations_Suppressed) - { - str = ""; - line_number = 0; - column_number = 0; - } - else if (Present (gnat_node) && Sloc (gnat_node) != No_Location) - { - str = Get_Name_String - (Debug_Source_Name (Get_Source_File_Index (Sloc (gnat_node)))); - line_number = Get_Logical_Line_Number (Sloc (gnat_node)); - column_number = Get_Column_Number (Sloc (gnat_node)); - } - else - { - str = lbasename (LOCATION_FILE (input_location)); - line_number = LOCATION_LINE (input_location); - column_number = LOCATION_COLUMN (input_location); - } - - const int len = strlen (str); - *filename = build_string (len, str); - TREE_TYPE (*filename) = build_array_type (char_type_node, - build_index_type (size_int (len))); - *line = build_int_cst (NULL_TREE, line_number); - if (col) - *col = build_int_cst (NULL_TREE, column_number); -} - -/* Build a call to a function that raises an exception and passes file name - and line number, if requested. MSG says which exception function to call. - GNAT_NODE is the node conveying the source location for which the error - should be signaled, or Empty in which case the error is signaled for the - current location. KIND says which kind of exception node this is for, - among N_Raise_{Constraint,Storage,Program}_Error. */ - -tree -build_call_raise (int msg, Node_Id gnat_node, char kind) -{ - Entity_Id gnat_label = get_exception_label (kind); - tree fndecl = gnat_raise_decls[msg]; - tree filename, line; - - /* If this is to be done as a goto, handle that case. */ - if (Present (gnat_label)) - return build_goto_raise (gnat_label, msg); - - expand_sloc (gnat_node, &filename, &line, NULL); - - return - build_call_n_expr (fndecl, 2, - build1 (ADDR_EXPR, - build_pointer_type (char_type_node), - filename), - line); -} - -/* Similar to build_call_raise, with extra information about the column - where the check failed. */ - -tree -build_call_raise_column (int msg, Node_Id gnat_node, char kind) -{ - Entity_Id gnat_label = get_exception_label (kind); - tree fndecl = gnat_raise_decls_ext[msg]; - tree filename, line, col; - - /* If this is to be done as a goto, handle that case. */ - if (Present (gnat_label)) - return build_goto_raise (gnat_label, msg); - - expand_sloc (gnat_node, &filename, &line, &col); - - return - build_call_n_expr (fndecl, 3, - build1 (ADDR_EXPR, - build_pointer_type (char_type_node), - filename), - line, col); -} - -/* Similar to build_call_raise_column, for an index or range check exception , - with extra information of the form "INDEX out of range FIRST..LAST". */ - -tree -build_call_raise_range (int msg, Node_Id gnat_node, char kind, - tree index, tree first, tree last) -{ - Entity_Id gnat_label = get_exception_label (kind); - tree fndecl = gnat_raise_decls_ext[msg]; - tree filename, line, col; - - /* If this is to be done as a goto, handle that case. */ - if (Present (gnat_label)) - return build_goto_raise (gnat_label, msg); - - expand_sloc (gnat_node, &filename, &line, &col); - - return - build_call_n_expr (fndecl, 6, - build1 (ADDR_EXPR, - build_pointer_type (char_type_node), - filename), - line, col, - convert (integer_type_node, index), - convert (integer_type_node, first), - convert (integer_type_node, last)); -} - -/* qsort comparer for the bit positions of two constructor elements - for record components. */ - -static int -compare_elmt_bitpos (const PTR rt1, const PTR rt2) -{ - const constructor_elt * const elmt1 = (const constructor_elt *) rt1; - const constructor_elt * const elmt2 = (const constructor_elt *) rt2; - const_tree const field1 = elmt1->index; - const_tree const field2 = elmt2->index; - const int ret - = tree_int_cst_compare (bit_position (field1), bit_position (field2)); - - return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2)); -} - -/* Return a CONSTRUCTOR of TYPE whose elements are V. */ - -tree -gnat_build_constructor (tree type, vec<constructor_elt, va_gc> *v) -{ - bool allconstant = (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST); - bool read_only = true; - bool side_effects = false; - tree result, obj, val; - unsigned int n_elmts; - - /* Scan the elements to see if they are all constant or if any has side - effects, to let us set global flags on the resulting constructor. Count - the elements along the way for possible sorting purposes below. */ - FOR_EACH_CONSTRUCTOR_ELT (v, n_elmts, obj, val) - { - /* The predicate must be in keeping with output_constructor and, unlike - initializer_constant_valid_p, we accept "&{...}" because we'll put - the CONSTRUCTOR into the constant pool during gimplification. */ - if ((!TREE_CONSTANT (val) && !TREE_STATIC (val)) - || (TREE_CODE (type) == RECORD_TYPE - && CONSTRUCTOR_BITFIELD_P (obj) - && !initializer_constant_valid_for_bitfield_p (val)) - || (!initializer_constant_valid_p (val, - TREE_TYPE (val), - TYPE_REVERSE_STORAGE_ORDER (type)) - && !(TREE_CODE (val) == ADDR_EXPR - && TREE_CODE (TREE_OPERAND (val, 0)) == CONSTRUCTOR - && TREE_CONSTANT (TREE_OPERAND (val, 0))))) - allconstant = false; - - if (!TREE_READONLY (val)) - read_only = false; - - if (TREE_SIDE_EFFECTS (val)) - side_effects = true; - } - - /* For record types with constant components only, sort field list - by increasing bit position. This is necessary to ensure the - constructor can be output as static data. */ - if (allconstant && TREE_CODE (type) == RECORD_TYPE && n_elmts > 1) - v->qsort (compare_elmt_bitpos); - - result = build_constructor (type, v); - CONSTRUCTOR_NO_CLEARING (result) = 1; - TREE_CONSTANT (result) = TREE_STATIC (result) = allconstant; - TREE_SIDE_EFFECTS (result) = side_effects; - TREE_READONLY (result) = TYPE_READONLY (type) || read_only || allconstant; - return result; -} - -/* Return a COMPONENT_REF to access FIELD in RECORD, or NULL_TREE if the field - is not found in the record. Don't fold the result if NO_FOLD is true. */ - -static tree -build_simple_component_ref (tree record, tree field, bool no_fold) -{ - tree type = TYPE_MAIN_VARIANT (TREE_TYPE (record)); - tree ref; - - /* The failure of this assertion will very likely come from a missing - insertion of an explicit dereference. */ - gcc_assert (RECORD_OR_UNION_TYPE_P (type) && COMPLETE_TYPE_P (type)); - - /* Try to fold a conversion from another record or union type unless the type - contains a placeholder as it might be needed for a later substitution. */ - if (TREE_CODE (record) == VIEW_CONVERT_EXPR - && RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (record, 0))) - && !type_contains_placeholder_p (type)) - { - tree op = TREE_OPERAND (record, 0); - - /* If this is an unpadding operation, convert the underlying object to - the unpadded type directly. */ - if (TYPE_IS_PADDING_P (type) && field == TYPE_FIELDS (type)) - return convert (TREE_TYPE (field), op); - - /* Otherwise try to access FIELD directly in the underlying type, but - make sure that the form of the reference doesn't change too much; - this can happen for an unconstrained bit-packed array type whose - constrained form can be an integer type. */ - ref = build_simple_component_ref (op, field, no_fold); - if (ref && TREE_CODE (TREE_TYPE (ref)) == TREE_CODE (TREE_TYPE (field))) - return ref; - } - - /* If this field is not in the specified record, see if we can find a field - in the specified record whose original field is the same as this one. */ - if (DECL_CONTEXT (field) != type) - { - tree new_field; - - /* First loop through normal components. */ - for (new_field = TYPE_FIELDS (type); - new_field; - new_field = DECL_CHAIN (new_field)) - if (SAME_FIELD_P (field, new_field)) - break; - - /* Next, loop through DECL_INTERNAL_P components if we haven't found the - component in the first search. Doing this search in two steps is - required to avoid hidden homonymous fields in the _Parent field. */ - if (!new_field) - for (new_field = TYPE_FIELDS (type); - new_field; - new_field = DECL_CHAIN (new_field)) - if (DECL_INTERNAL_P (new_field) - && RECORD_OR_UNION_TYPE_P (TREE_TYPE (new_field))) - { - tree field_ref - = build_simple_component_ref (record, new_field, no_fold); - ref = build_simple_component_ref (field_ref, field, no_fold); - if (ref) - return ref; - } - - field = new_field; - } - - if (!field) - return NULL_TREE; - - /* If the field's offset has overflowed, do not try to access it, as doing - so may trigger sanity checks deeper in the back-end. Note that we don't - need to warn since this will be done on trying to declare the object. */ - if (TREE_CODE (DECL_FIELD_OFFSET (field)) == INTEGER_CST - && TREE_OVERFLOW (DECL_FIELD_OFFSET (field))) - return build1 (NULL_EXPR, TREE_TYPE (field), - build_call_raise (SE_Object_Too_Large, Empty, - N_Raise_Storage_Error)); - - ref = build3 (COMPONENT_REF, TREE_TYPE (field), record, field, NULL_TREE); - - if (TREE_READONLY (record) - || TREE_READONLY (field) - || TYPE_READONLY (type)) - TREE_READONLY (ref) = 1; - - if (TREE_THIS_VOLATILE (record) - || TREE_THIS_VOLATILE (field) - || TYPE_VOLATILE (type)) - TREE_THIS_VOLATILE (ref) = 1; - - if (no_fold) - return ref; - - /* The generic folder may punt in this case because the inner array type - can be self-referential, but folding is in fact not problematic. */ - if (TREE_CODE (record) == CONSTRUCTOR - && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (record))) - { - vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (record); - unsigned HOST_WIDE_INT idx; - tree index, value; - FOR_EACH_CONSTRUCTOR_ELT (elts, idx, index, value) - if (index == field) - return value; - return ref; - } - - return fold (ref); -} - -/* Likewise, but return NULL_EXPR and generate a Program_Error if the - field is not found in the record. */ - -tree -build_component_ref (tree record, tree field, bool no_fold) -{ - tree ref = build_simple_component_ref (record, field, no_fold); - if (ref) - return ref; - - /* The missing field should have been detected in the front-end. */ - gigi_checking_assert (false); - - /* Assume this is an invalid user field so raise Program_Error. */ - return build1 (NULL_EXPR, TREE_TYPE (field), - build_call_raise (PE_Explicit_Raise, Empty, - N_Raise_Program_Error)); -} - -/* Helper for build_call_alloc_dealloc, with arguments to be interpreted - identically. Process the case where a GNAT_PROC to call is provided. */ - -static inline tree -build_call_alloc_dealloc_proc (tree gnu_obj, tree gnu_size, tree gnu_type, - Entity_Id gnat_proc, Entity_Id gnat_pool) -{ - tree gnu_proc = gnat_to_gnu (gnat_proc); - tree gnu_call; - - /* A storage pool's underlying type is a record type (for both predefined - storage pools and GNAT simple storage pools). The secondary stack uses - the same mechanism, but its pool object (SS_Pool) is an integer. */ - if (Is_Record_Type (Underlying_Type (Etype (gnat_pool)))) - { - /* The size is the third parameter; the alignment is the - same type. */ - Entity_Id gnat_size_type - = Etype (Next_Formal (Next_Formal (First_Formal (gnat_proc)))); - tree gnu_size_type = gnat_to_gnu_type (gnat_size_type); - - tree gnu_pool = gnat_to_gnu (gnat_pool); - tree gnu_pool_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_pool); - tree gnu_align = size_int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT); - - gnu_size = convert (gnu_size_type, gnu_size); - gnu_align = convert (gnu_size_type, gnu_align); - - /* The first arg is always the address of the storage pool; next - comes the address of the object, for a deallocator, then the - size and alignment. */ - if (gnu_obj) - gnu_call = build_call_n_expr (gnu_proc, 4, gnu_pool_addr, gnu_obj, - gnu_size, gnu_align); - else - gnu_call = build_call_n_expr (gnu_proc, 3, gnu_pool_addr, - gnu_size, gnu_align); - } - - /* Secondary stack case. */ - else - { - /* The size is the second parameter. */ - Entity_Id gnat_size_type - = Etype (Next_Formal (First_Formal (gnat_proc))); - tree gnu_size_type = gnat_to_gnu_type (gnat_size_type); - - gnu_size = convert (gnu_size_type, gnu_size); - - /* The first arg is the address of the object, for a deallocator, - then the size. */ - if (gnu_obj) - gnu_call = build_call_n_expr (gnu_proc, 2, gnu_obj, gnu_size); - else - gnu_call = build_call_n_expr (gnu_proc, 1, gnu_size); - } - - return gnu_call; -} - -/* Helper for build_call_alloc_dealloc, to build and return an allocator for - DATA_SIZE bytes aimed at containing a DATA_TYPE object, using the default - __gnat_malloc allocator. Honor DATA_TYPE alignments greater than what the - latter offers. */ - -static inline tree -maybe_wrap_malloc (tree data_size, tree data_type, Node_Id gnat_node) -{ - /* When the DATA_TYPE alignment is stricter than what malloc offers - (super-aligned case), we allocate an "aligning" wrapper type and return - the address of its single data field with the malloc's return value - stored just in front. */ - - unsigned int data_align = TYPE_ALIGN (data_type); - unsigned int system_allocator_alignment - = get_target_system_allocator_alignment () * BITS_PER_UNIT; - - tree aligning_type - = ((data_align > system_allocator_alignment) - ? make_aligning_type (data_type, data_align, data_size, - system_allocator_alignment, - POINTER_SIZE / BITS_PER_UNIT, - gnat_node) - : NULL_TREE); - - tree size_to_malloc - = aligning_type ? TYPE_SIZE_UNIT (aligning_type) : data_size; - - tree malloc_ptr = build_call_n_expr (malloc_decl, 1, size_to_malloc); - - if (aligning_type) - { - /* Latch malloc's return value and get a pointer to the aligning field - first. */ - tree storage_ptr = gnat_protect_expr (malloc_ptr); - - tree aligning_record_addr - = convert (build_pointer_type (aligning_type), storage_ptr); - - tree aligning_record - = build_unary_op (INDIRECT_REF, NULL_TREE, aligning_record_addr); - - tree aligning_field - = build_component_ref (aligning_record, TYPE_FIELDS (aligning_type), - false); - - tree aligning_field_addr - = build_unary_op (ADDR_EXPR, NULL_TREE, aligning_field); - - /* Then arrange to store the allocator's return value ahead - and return. */ - tree storage_ptr_slot_addr - = build_binary_op (POINTER_PLUS_EXPR, ptr_type_node, - convert (ptr_type_node, aligning_field_addr), - size_int (-(HOST_WIDE_INT) POINTER_SIZE - / BITS_PER_UNIT)); - - tree storage_ptr_slot - = build_unary_op (INDIRECT_REF, NULL_TREE, - convert (build_pointer_type (ptr_type_node), - storage_ptr_slot_addr)); - - return - build2 (COMPOUND_EXPR, TREE_TYPE (aligning_field_addr), - build_binary_op (INIT_EXPR, NULL_TREE, - storage_ptr_slot, storage_ptr), - aligning_field_addr); - } - else - return malloc_ptr; -} - -/* Helper for build_call_alloc_dealloc, to release a DATA_TYPE object - designated by DATA_PTR using the __gnat_free entry point. */ - -static inline tree -maybe_wrap_free (tree data_ptr, tree data_type) -{ - /* In the regular alignment case, we pass the data pointer straight to free. - In the superaligned case, we need to retrieve the initial allocator - return value, stored in front of the data block at allocation time. */ - - unsigned int data_align = TYPE_ALIGN (data_type); - unsigned int system_allocator_alignment - = get_target_system_allocator_alignment () * BITS_PER_UNIT; - - tree free_ptr; - - if (data_align > system_allocator_alignment) - { - /* DATA_FRONT_PTR (void *) - = (void *)DATA_PTR - (void *)sizeof (void *)) */ - tree data_front_ptr - = build_binary_op - (POINTER_PLUS_EXPR, ptr_type_node, - convert (ptr_type_node, data_ptr), - size_int (-(HOST_WIDE_INT) POINTER_SIZE / BITS_PER_UNIT)); - - /* FREE_PTR (void *) = *(void **)DATA_FRONT_PTR */ - free_ptr - = build_unary_op - (INDIRECT_REF, NULL_TREE, - convert (build_pointer_type (ptr_type_node), data_front_ptr)); - } - else - free_ptr = data_ptr; - - return build_call_n_expr (free_decl, 1, free_ptr); -} - -/* Build a GCC tree to call an allocation or deallocation function. - If GNU_OBJ is nonzero, it is an object to deallocate. Otherwise, - generate an allocator. - - GNU_SIZE is the number of bytes to allocate and GNU_TYPE is the contained - object type, used to determine the to-be-honored address alignment. - GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the storage - pool to use. If not present, malloc and free are used. GNAT_NODE is used - to provide an error location for restriction violation messages. */ - -tree -build_call_alloc_dealloc (tree gnu_obj, tree gnu_size, tree gnu_type, - Entity_Id gnat_proc, Entity_Id gnat_pool, - Node_Id gnat_node) -{ - /* Explicit proc to call ? This one is assumed to deal with the type - alignment constraints. */ - if (Present (gnat_proc)) - return build_call_alloc_dealloc_proc (gnu_obj, gnu_size, gnu_type, - gnat_proc, gnat_pool); - - /* Otherwise, object to "free" or "malloc" with possible special processing - for alignments stricter than what the default allocator honors. */ - else if (gnu_obj) - return maybe_wrap_free (gnu_obj, gnu_type); - else - { - /* Assert that we no longer can be called with this special pool. */ - gcc_assert (gnat_pool != -1); - - /* Check that we aren't violating the associated restriction. */ - if (!(Nkind (gnat_node) == N_Allocator && Comes_From_Source (gnat_node))) - { - Check_No_Implicit_Heap_Alloc (gnat_node); - if (Has_Task (Etype (gnat_node))) - Check_No_Implicit_Task_Alloc (gnat_node); - if (Has_Protected (Etype (gnat_node))) - Check_No_Implicit_Protected_Alloc (gnat_node); - } - return maybe_wrap_malloc (gnu_size, gnu_type, gnat_node); - } -} - -/* Build a GCC tree that corresponds to allocating an object of TYPE whose - initial value is INIT, if INIT is nonzero. Convert the expression to - RESULT_TYPE, which must be some pointer type, and return the result. - - GNAT_PROC and GNAT_POOL optionally give the procedure to call and - the storage pool to use. GNAT_NODE is used to provide an error - location for restriction violation messages. If IGNORE_INIT_TYPE is - true, ignore the type of INIT for the purpose of determining the size; - this will cause the maximum size to be allocated if TYPE is of - self-referential size. */ - -tree -build_allocator (tree type, tree init, tree result_type, Entity_Id gnat_proc, - Entity_Id gnat_pool, Node_Id gnat_node, bool ignore_init_type) -{ - tree size, storage, storage_deref, storage_init; - - /* If the initializer, if present, is a NULL_EXPR, just return a new one. */ - if (init && TREE_CODE (init) == NULL_EXPR) - return build1 (NULL_EXPR, result_type, TREE_OPERAND (init, 0)); - - /* If we are just annotating types, also return a NULL_EXPR. */ - else if (type_annotate_only) - return build1 (NULL_EXPR, result_type, - build_call_raise (CE_Range_Check_Failed, gnat_node, - N_Raise_Constraint_Error)); - - /* If the initializer, if present, is a COND_EXPR, deal with each branch. */ - else if (init && TREE_CODE (init) == COND_EXPR) - return build3 (COND_EXPR, result_type, TREE_OPERAND (init, 0), - build_allocator (type, TREE_OPERAND (init, 1), result_type, - gnat_proc, gnat_pool, gnat_node, - ignore_init_type), - build_allocator (type, TREE_OPERAND (init, 2), result_type, - gnat_proc, gnat_pool, gnat_node, - ignore_init_type)); - - /* If RESULT_TYPE is a fat or thin pointer, set SIZE to be the sum of the - sizes of the object and its template. Allocate the whole thing and - fill in the parts that are known. */ - else if (TYPE_IS_FAT_OR_THIN_POINTER_P (result_type)) - { - tree storage_type - = build_unc_object_type_from_ptr (result_type, type, - get_identifier ("ALLOC"), false); - tree template_type = TREE_TYPE (TYPE_FIELDS (storage_type)); - tree storage_ptr_type = build_pointer_type (storage_type); - - size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (storage_type), - init); - - /* If the size overflows, pass -1 so Storage_Error will be raised. */ - if (TREE_CODE (size) == INTEGER_CST && !valid_constant_size_p (size)) - size = size_int (-1); - - storage = build_call_alloc_dealloc (NULL_TREE, size, storage_type, - gnat_proc, gnat_pool, gnat_node); - storage = convert (storage_ptr_type, gnat_protect_expr (storage)); - storage_deref = build_unary_op (INDIRECT_REF, NULL_TREE, storage); - TREE_THIS_NOTRAP (storage_deref) = 1; - - /* If there is an initializing expression, then make a constructor for - the entire object including the bounds and copy it into the object. - If there is no initializing expression, just set the bounds. */ - if (init) - { - vec<constructor_elt, va_gc> *v; - vec_alloc (v, 2); - - CONSTRUCTOR_APPEND_ELT (v, TYPE_FIELDS (storage_type), - build_template (template_type, type, init)); - CONSTRUCTOR_APPEND_ELT (v, DECL_CHAIN (TYPE_FIELDS (storage_type)), - init); - storage_init - = build_binary_op (INIT_EXPR, NULL_TREE, storage_deref, - gnat_build_constructor (storage_type, v)); - } - else - storage_init - = build_binary_op (INIT_EXPR, NULL_TREE, - build_component_ref (storage_deref, - TYPE_FIELDS (storage_type), - false), - build_template (template_type, type, NULL_TREE)); - - return build2 (COMPOUND_EXPR, result_type, - storage_init, convert (result_type, storage)); - } - - size = TYPE_SIZE_UNIT (type); - - /* If we have an initializing expression, see if its size is simpler - than the size from the type. */ - if (!ignore_init_type && init && TYPE_SIZE_UNIT (TREE_TYPE (init)) - && (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (init))) == INTEGER_CST - || CONTAINS_PLACEHOLDER_P (size))) - size = TYPE_SIZE_UNIT (TREE_TYPE (init)); - - /* If the size is still self-referential, reference the initializing - expression, if it is present. If not, this must have been a call - to allocate a library-level object, in which case we just use the - maximum size. */ - if (!ignore_init_type && init) - size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, init); - else if (CONTAINS_PLACEHOLDER_P (size)) - size = max_size (size, true); - - /* If the size overflows, pass -1 so Storage_Error will be raised. */ - if (TREE_CODE (size) == INTEGER_CST && !valid_constant_size_p (size)) - size = size_int (-1); - - storage = convert (result_type, - build_call_alloc_dealloc (NULL_TREE, size, type, - gnat_proc, gnat_pool, - gnat_node)); - - /* If we have an initial value, protect the new address, assign the value - and return the address with a COMPOUND_EXPR. */ - if (init) - { - storage = gnat_protect_expr (storage); - storage_deref = build_unary_op (INDIRECT_REF, NULL_TREE, storage); - TREE_THIS_NOTRAP (storage_deref) = 1; - storage_init - = build_binary_op (INIT_EXPR, NULL_TREE, storage_deref, init); - return build2 (COMPOUND_EXPR, result_type, storage_init, storage); - } - - return storage; -} - -/* Indicate that we need to take the address of T and that it therefore - should not be allocated in a register. Return true if successful. */ - -bool -gnat_mark_addressable (tree t) -{ - while (true) - switch (TREE_CODE (t)) - { - case ADDR_EXPR: - case COMPONENT_REF: - case ARRAY_REF: - case ARRAY_RANGE_REF: - case REALPART_EXPR: - case IMAGPART_EXPR: - case VIEW_CONVERT_EXPR: - case NON_LVALUE_EXPR: - CASE_CONVERT: - t = TREE_OPERAND (t, 0); - break; - - case COMPOUND_EXPR: - t = TREE_OPERAND (t, 1); - break; - - case CONSTRUCTOR: - TREE_ADDRESSABLE (t) = 1; - return true; - - case VAR_DECL: - case PARM_DECL: - case RESULT_DECL: - TREE_ADDRESSABLE (t) = 1; - return true; - - case FUNCTION_DECL: - TREE_ADDRESSABLE (t) = 1; - return true; - - case CONST_DECL: - return DECL_CONST_CORRESPONDING_VAR (t) - && gnat_mark_addressable (DECL_CONST_CORRESPONDING_VAR (t)); - - default: - return true; - } -} - -/* Return true if EXP is a stable expression for the purpose of the functions - below and, therefore, can be returned unmodified by them. We accept things - that are actual constants or that have already been handled. */ - -static bool -gnat_stable_expr_p (tree exp) -{ - enum tree_code code = TREE_CODE (exp); - return TREE_CONSTANT (exp) || code == NULL_EXPR || code == SAVE_EXPR; -} - -/* Save EXP for later use or reuse. This is equivalent to save_expr in tree.c - but we know how to handle our own nodes. */ - -tree -gnat_save_expr (tree exp) -{ - tree type = TREE_TYPE (exp); - enum tree_code code = TREE_CODE (exp); - - if (gnat_stable_expr_p (exp)) - return exp; - - if (code == UNCONSTRAINED_ARRAY_REF) - { - tree t = build1 (code, type, gnat_save_expr (TREE_OPERAND (exp, 0))); - TREE_READONLY (t) = TYPE_READONLY (type); - return t; - } - - /* If this is a COMPONENT_REF of a fat pointer, save the entire fat pointer. - This may be more efficient, but will also allow us to more easily find - the match for the PLACEHOLDER_EXPR. */ - if (code == COMPONENT_REF - && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (exp, 0)))) - return build3 (code, type, gnat_save_expr (TREE_OPERAND (exp, 0)), - TREE_OPERAND (exp, 1), NULL_TREE); - - return save_expr (exp); -} - -/* Protect EXP for immediate reuse. This is a variant of gnat_save_expr that - is optimized under the assumption that EXP's value doesn't change before - its subsequent reuse(s) except through its potential reevaluation. */ - -tree -gnat_protect_expr (tree exp) -{ - tree type = TREE_TYPE (exp); - enum tree_code code = TREE_CODE (exp); - - if (gnat_stable_expr_p (exp)) - return exp; - - /* If EXP has no side effects, we theoretically don't need to do anything. - However, we may be recursively passed more and more complex expressions - involving checks which will be reused multiple times and eventually be - unshared for gimplification; in order to avoid a complexity explosion - at that point, we protect any expressions more complex than a simple - arithmetic expression. */ - if (!TREE_SIDE_EFFECTS (exp)) - { - tree inner = skip_simple_arithmetic (exp); - if (!EXPR_P (inner) || REFERENCE_CLASS_P (inner)) - return exp; - } - - /* If this is a conversion, protect what's inside the conversion. */ - if (code == NON_LVALUE_EXPR - || CONVERT_EXPR_CODE_P (code) - || code == VIEW_CONVERT_EXPR) - return build1 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0))); - - /* If we're indirectly referencing something, we only need to protect the - address since the data itself can't change in these situations. */ - if (code == INDIRECT_REF || code == UNCONSTRAINED_ARRAY_REF) - { - tree t = build1 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0))); - TREE_READONLY (t) = TYPE_READONLY (type); - return t; - } - - /* Likewise if we're indirectly referencing part of something. */ - if (code == COMPONENT_REF - && TREE_CODE (TREE_OPERAND (exp, 0)) == INDIRECT_REF) - return build3 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)), - TREE_OPERAND (exp, 1), NULL_TREE); - - /* If this is a COMPONENT_REF of a fat pointer, save the entire fat pointer. - This may be more efficient, but will also allow us to more easily find - the match for the PLACEHOLDER_EXPR. */ - if (code == COMPONENT_REF - && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (exp, 0)))) - return build3 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)), - TREE_OPERAND (exp, 1), NULL_TREE); - - /* If this is a fat pointer or a scalar, just make a SAVE_EXPR. Likewise - for a CALL_EXPR as large objects are returned via invisible reference - in most ABIs so the temporary will directly be filled by the callee. */ - if (TYPE_IS_FAT_POINTER_P (type) - || !AGGREGATE_TYPE_P (type) - || code == CALL_EXPR) - return save_expr (exp); - - /* Otherwise reference, protect the address and dereference. */ - return - build_unary_op (INDIRECT_REF, type, - save_expr (build_unary_op (ADDR_EXPR, NULL_TREE, exp))); -} - -/* This is equivalent to stabilize_reference_1 in tree.c but we take an extra - argument to force evaluation of everything. */ - -static tree -gnat_stabilize_reference_1 (tree e, void *data) -{ - const bool force = *(bool *)data; - enum tree_code code = TREE_CODE (e); - tree type = TREE_TYPE (e); - tree result; - - if (gnat_stable_expr_p (e)) - return e; - - switch (TREE_CODE_CLASS (code)) - { - case tcc_exceptional: - case tcc_declaration: - case tcc_comparison: - case tcc_expression: - case tcc_reference: - case tcc_vl_exp: - /* If this is a COMPONENT_REF of a fat pointer, save the entire - fat pointer. This may be more efficient, but will also allow - us to more easily find the match for the PLACEHOLDER_EXPR. */ - if (code == COMPONENT_REF - && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (e, 0)))) - result - = build3 (code, type, - gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), data), - TREE_OPERAND (e, 1), NULL_TREE); - /* If the expression has side-effects, then encase it in a SAVE_EXPR - so that it will only be evaluated once. */ - /* The tcc_reference and tcc_comparison classes could be handled as - below, but it is generally faster to only evaluate them once. */ - else if (TREE_SIDE_EFFECTS (e) || force) - return save_expr (e); - else - return e; - break; - - case tcc_binary: - /* Recursively stabilize each operand. */ - result - = build2 (code, type, - gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), data), - gnat_stabilize_reference_1 (TREE_OPERAND (e, 1), data)); - break; - - case tcc_unary: - /* Recursively stabilize each operand. */ - result - = build1 (code, type, - gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), data)); - break; - - default: - gcc_unreachable (); - } - - /* See gnat_rewrite_reference below for the rationale. */ - TREE_READONLY (result) = TREE_READONLY (e); - TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e); - - if (TREE_SIDE_EFFECTS (e)) - TREE_SIDE_EFFECTS (result) = 1; - - return result; -} - -/* This is equivalent to stabilize_reference in tree.c but we know how to - handle our own nodes and we take extra arguments. FORCE says whether to - force evaluation of everything in REF. INIT is set to the first arm of - a COMPOUND_EXPR present in REF, if any. */ - -tree -gnat_stabilize_reference (tree ref, bool force, tree *init) -{ - return - gnat_rewrite_reference (ref, gnat_stabilize_reference_1, &force, init); -} - -/* Rewrite reference REF and call FUNC on each expression within REF in the - process. DATA is passed unmodified to FUNC. INIT is set to the first - arm of a COMPOUND_EXPR present in REF, if any. */ - -tree -gnat_rewrite_reference (tree ref, rewrite_fn func, void *data, tree *init) -{ - tree type = TREE_TYPE (ref); - enum tree_code code = TREE_CODE (ref); - tree result; - - switch (code) - { - case CONST_DECL: - case VAR_DECL: - case PARM_DECL: - case RESULT_DECL: - /* No action is needed in this case. */ - return ref; - - CASE_CONVERT: - case FLOAT_EXPR: - case FIX_TRUNC_EXPR: - case REALPART_EXPR: - case IMAGPART_EXPR: - case VIEW_CONVERT_EXPR: - result - = build1 (code, type, - gnat_rewrite_reference (TREE_OPERAND (ref, 0), func, data, - init)); - break; - - case INDIRECT_REF: - case UNCONSTRAINED_ARRAY_REF: - result = build1 (code, type, func (TREE_OPERAND (ref, 0), data)); - break; - - case COMPONENT_REF: - result = build3 (COMPONENT_REF, type, - gnat_rewrite_reference (TREE_OPERAND (ref, 0), func, - data, init), - TREE_OPERAND (ref, 1), NULL_TREE); - break; - - case BIT_FIELD_REF: - result = build3 (BIT_FIELD_REF, type, - gnat_rewrite_reference (TREE_OPERAND (ref, 0), func, - data, init), - TREE_OPERAND (ref, 1), TREE_OPERAND (ref, 2)); - REF_REVERSE_STORAGE_ORDER (result) = REF_REVERSE_STORAGE_ORDER (ref); - break; - - case ARRAY_REF: - case ARRAY_RANGE_REF: - result - = build4 (code, type, - gnat_rewrite_reference (TREE_OPERAND (ref, 0), func, data, - init), - func (TREE_OPERAND (ref, 1), data), - TREE_OPERAND (ref, 2), NULL_TREE); - break; - - case COMPOUND_EXPR: - gcc_assert (!*init); - *init = TREE_OPERAND (ref, 0); - /* We expect only the pattern built in Call_to_gnu. */ - gcc_assert (DECL_P (TREE_OPERAND (ref, 1)) - || (TREE_CODE (TREE_OPERAND (ref, 1)) == COMPONENT_REF - && DECL_P (TREE_OPERAND (TREE_OPERAND (ref, 1), 0)))); - return TREE_OPERAND (ref, 1); - - case CALL_EXPR: - { - /* This can only be an atomic load. */ - gcc_assert (call_is_atomic_load (ref)); - - /* An atomic load is an INDIRECT_REF of its first argument. */ - tree t = CALL_EXPR_ARG (ref, 0); - if (TREE_CODE (t) == NOP_EXPR) - t = TREE_OPERAND (t, 0); - if (TREE_CODE (t) == ADDR_EXPR) - t = build1 (ADDR_EXPR, TREE_TYPE (t), - gnat_rewrite_reference (TREE_OPERAND (t, 0), func, data, - init)); - else - t = func (t, data); - t = fold_convert (TREE_TYPE (CALL_EXPR_ARG (ref, 0)), t); - - result = build_call_expr (TREE_OPERAND (CALL_EXPR_FN (ref), 0), 2, - t, CALL_EXPR_ARG (ref, 1)); - } - break; - - case ERROR_MARK: - case NULL_EXPR: - return ref; - - default: - gcc_unreachable (); - } - - /* TREE_READONLY and TREE_THIS_VOLATILE set on the initial expression may - not be sustained across some paths, such as the one for INDIRECT_REF. - - Special care should be taken regarding TREE_SIDE_EFFECTS, because some - paths introduce side-effects where there was none initially (e.g. if a - SAVE_EXPR is built) and we also want to keep track of that. */ - TREE_READONLY (result) = TREE_READONLY (ref); - TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref); - - if (TREE_SIDE_EFFECTS (ref)) - TREE_SIDE_EFFECTS (result) = 1; - - if (code == INDIRECT_REF - || code == UNCONSTRAINED_ARRAY_REF - || code == ARRAY_REF - || code == ARRAY_RANGE_REF) - TREE_THIS_NOTRAP (result) = TREE_THIS_NOTRAP (ref); - - return result; -} - -/* This is equivalent to get_inner_reference in expr.c but it returns the - ultimate containing object only if the reference (lvalue) is constant, - i.e. if it doesn't depend on the context in which it is evaluated. */ - -tree -get_inner_constant_reference (tree exp) -{ - while (true) - { - switch (TREE_CODE (exp)) - { - case BIT_FIELD_REF: - break; - - case COMPONENT_REF: - if (!TREE_CONSTANT (DECL_FIELD_OFFSET (TREE_OPERAND (exp, 1)))) - return NULL_TREE; - break; - - case ARRAY_REF: - case ARRAY_RANGE_REF: - { - if (TREE_OPERAND (exp, 2)) - return NULL_TREE; - - tree array_type = TREE_TYPE (TREE_OPERAND (exp, 0)); - if (!TREE_CONSTANT (TREE_OPERAND (exp, 1)) - || !TREE_CONSTANT (TYPE_MIN_VALUE (TYPE_DOMAIN (array_type))) - || !TREE_CONSTANT (TYPE_SIZE_UNIT (TREE_TYPE (array_type)))) - return NULL_TREE; - } - break; - - case REALPART_EXPR: - case IMAGPART_EXPR: - case VIEW_CONVERT_EXPR: - break; - - default: - goto done; - } - - exp = TREE_OPERAND (exp, 0); - } - -done: - return exp; -} - -/* Return true if EXPR is the addition or the subtraction of a constant and, - if so, set *ADD to the addend, *CST to the constant and *MINUS_P to true - if this is a subtraction. */ - -bool -is_simple_additive_expression (tree expr, tree *add, tree *cst, bool *minus_p) -{ - /* Skip overflow checks. */ - if (TREE_CODE (expr) == COND_EXPR - && TREE_CODE (COND_EXPR_THEN (expr)) == COMPOUND_EXPR - && TREE_CODE (TREE_OPERAND (COND_EXPR_THEN (expr), 0)) == CALL_EXPR - && get_callee_fndecl (TREE_OPERAND (COND_EXPR_THEN (expr), 0)) - == gnat_raise_decls[CE_Overflow_Check_Failed]) - expr = COND_EXPR_ELSE (expr); - - if (TREE_CODE (expr) == PLUS_EXPR) - { - if (TREE_CONSTANT (TREE_OPERAND (expr, 0))) - { - *add = TREE_OPERAND (expr, 1); - *cst = TREE_OPERAND (expr, 0); - *minus_p = false; - return true; - } - else if (TREE_CONSTANT (TREE_OPERAND (expr, 1))) - { - *add = TREE_OPERAND (expr, 0); - *cst = TREE_OPERAND (expr, 1); - *minus_p = false; - return true; - } - } - else if (TREE_CODE (expr) == MINUS_EXPR) - { - if (TREE_CONSTANT (TREE_OPERAND (expr, 1))) - { - *add = TREE_OPERAND (expr, 0); - *cst = TREE_OPERAND (expr, 1); - *minus_p = true; - return true; - } - } - - return false; -} - -/* If EXPR is an expression that is invariant in the current function, in the - sense that it can be evaluated anywhere in the function and any number of - times, return EXPR or an equivalent expression. Otherwise return NULL. */ - -tree -gnat_invariant_expr (tree expr) -{ - tree type = TREE_TYPE (expr); - tree add, cst; - bool minus_p; - - expr = remove_conversions (expr, false); - - /* Look through temporaries created to capture values. */ - while ((TREE_CODE (expr) == CONST_DECL - || (TREE_CODE (expr) == VAR_DECL && TREE_READONLY (expr))) - && decl_function_context (expr) == current_function_decl - && DECL_INITIAL (expr)) - { - expr = DECL_INITIAL (expr); - /* Look into CONSTRUCTORs built to initialize padded types. */ - expr = maybe_padded_object (expr); - expr = remove_conversions (expr, false); - } - - /* We are only interested in scalar types at the moment and, even if we may - have gone through padding types in the above loop, we must be back to a - scalar value at this point. */ - if (AGGREGATE_TYPE_P (TREE_TYPE (expr))) - return NULL_TREE; - - if (TREE_CONSTANT (expr)) - return fold_convert (type, expr); - - /* Deal with aligning patterns. */ - if (TREE_CODE (expr) == BIT_AND_EXPR - && TREE_CONSTANT (TREE_OPERAND (expr, 1))) - { - tree op0 = gnat_invariant_expr (TREE_OPERAND (expr, 0)); - if (op0) - return fold_build2 (BIT_AND_EXPR, type, op0, TREE_OPERAND (expr, 1)); - else - return NULL_TREE; - } - - /* Deal with addition or subtraction of constants. */ - if (is_simple_additive_expression (expr, &add, &cst, &minus_p)) - { - add = gnat_invariant_expr (add); - if (add) - return - fold_build2 (minus_p ? MINUS_EXPR : PLUS_EXPR, type, - fold_convert (type, add), fold_convert (type, cst)); - else - return NULL_TREE; - } - - bool invariant_p = false; - tree t = expr; - - while (true) - { - switch (TREE_CODE (t)) - { - case COMPONENT_REF: - invariant_p |= DECL_INVARIANT_P (TREE_OPERAND (t, 1)); - break; - - case ARRAY_REF: - case ARRAY_RANGE_REF: - if (!TREE_CONSTANT (TREE_OPERAND (t, 1)) || TREE_OPERAND (t, 2)) - return NULL_TREE; - break; - - case BIT_FIELD_REF: - case REALPART_EXPR: - case IMAGPART_EXPR: - case VIEW_CONVERT_EXPR: - CASE_CONVERT: - break; - - case INDIRECT_REF: - if ((!invariant_p && !TREE_READONLY (t)) || TREE_SIDE_EFFECTS (t)) - return NULL_TREE; - invariant_p = false; - break; - - default: - goto object; - } - - t = TREE_OPERAND (t, 0); - } - -object: - if (TREE_SIDE_EFFECTS (t)) - return NULL_TREE; - - if (TREE_CODE (t) == CONST_DECL - && (DECL_EXTERNAL (t) - || decl_function_context (t) != current_function_decl)) - return fold_convert (type, expr); - - if (!invariant_p && !TREE_READONLY (t)) - return NULL_TREE; - - if (TREE_CODE (t) == PARM_DECL) - return fold_convert (type, expr); - - if (TREE_CODE (t) == VAR_DECL - && (DECL_EXTERNAL (t) - || decl_function_context (t) != current_function_decl)) - return fold_convert (type, expr); - - return NULL_TREE; -} |