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Diffstat (limited to 'gcc/ada/gcc-interface/utils2.c')
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diff --git a/gcc/ada/gcc-interface/utils2.c b/gcc/ada/gcc-interface/utils2.c new file mode 100644 index 0000000..300fbd3 --- /dev/null +++ b/gcc/ada/gcc-interface/utils2.c @@ -0,0 +1,2219 @@ +/**************************************************************************** + * * + * GNAT COMPILER COMPONENTS * + * * + * U T I L S 2 * + * * + * C Implementation File * + * * + * Copyright (C) 1992-2008, 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 "tm.h" +#include "tree.h" +#include "rtl.h" +#include "ggc.h" +#include "flags.h" +#include "output.h" +#include "ada.h" +#include "types.h" +#include "atree.h" +#include "stringt.h" +#include "namet.h" +#include "uintp.h" +#include "fe.h" +#include "elists.h" +#include "nlists.h" +#include "sinfo.h" +#include "einfo.h" +#include "ada-tree.h" +#include "gigi.h" + +static tree find_common_type (tree, tree); +static bool contains_save_expr_p (tree); +static tree contains_null_expr (tree); +static tree compare_arrays (tree, tree, tree); +static tree nonbinary_modular_operation (enum tree_code, tree, tree, tree); +static tree build_simple_component_ref (tree, tree, tree, bool); + +/* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical + operation. + + This preparation consists of taking the ordinary representation of + an expression expr and producing a valid tree boolean expression + describing whether expr is nonzero. We could simply always do + + build_binary_op (NE_EXPR, expr, integer_zero_node, 1), + + but we optimize comparisons, &&, ||, and !. + + The resulting type should always be the same as the input type. + This function is simpler than the corresponding C version since + the only possible operands will be things of Boolean type. */ + +tree +gnat_truthvalue_conversion (tree expr) +{ + tree type = TREE_TYPE (expr); + + switch (TREE_CODE (expr)) + { + case EQ_EXPR: case NE_EXPR: case LE_EXPR: case GE_EXPR: + case LT_EXPR: case GT_EXPR: + case TRUTH_ANDIF_EXPR: + case TRUTH_ORIF_EXPR: + case TRUTH_AND_EXPR: + case TRUTH_OR_EXPR: + case TRUTH_XOR_EXPR: + case ERROR_MARK: + return expr; + + case INTEGER_CST: + return (integer_zerop (expr) + ? build_int_cst (type, 0) + : build_int_cst (type, 1)); + + case REAL_CST: + return (real_zerop (expr) + ? fold_convert (type, integer_zero_node) + : fold_convert (type, integer_one_node)); + + case COND_EXPR: + /* Distribute the conversion into the arms of a COND_EXPR. */ + { + tree arg1 = gnat_truthvalue_conversion (TREE_OPERAND (expr, 1)); + tree arg2 = gnat_truthvalue_conversion (TREE_OPERAND (expr, 2)); + return fold_build3 (COND_EXPR, type, TREE_OPERAND (expr, 0), + arg1, arg2); + } + + default: + return build_binary_op (NE_EXPR, type, expr, + fold_convert (type, integer_zero_node)); + } +} + +/* 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 that address is aligned. Return that alignment + in bits. If we don't know anything about the alignment, 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 it's second operand. */ + this_alignment = known_alignment (TREE_OPERAND (exp, 1)); + break; + + case PLUS_EXPR: + case MINUS_EXPR: + /* If two address 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: + lhs = known_alignment (TREE_OPERAND (exp, 0)); + rhs = known_alignment (TREE_OPERAND (exp, 1)); + /* If we don't know the alignment of the offset, we assume that + of the base. */ + 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 smallest 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 = MIN (BITS_PER_UNIT * (c & -c), BIGGEST_ALIGNMENT); + } + 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: + this_alignment = expr_align (TREE_OPERAND (exp, 0)); + break; + + 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)))) + 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 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. */ + + /* We must prevent writing more than what the target may hold if this is for + an assignment and the case of tagged types is handled in build_binary_op + so 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 assignments. */ + if (TREE_CONSTANT (TYPE_SIZE (t1)) + && (!TREE_CONSTANT (TYPE_SIZE (t2)) + || !tree_int_cst_lt (TYPE_SIZE (t2), TYPE_SIZE (t1)))) + return t1; + + /* Otherwise, if the lhs type is non-BLKmode, use it. 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) + 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; +} + +/* See if EXP contains a SAVE_EXPR in a position where we would + normally put it. + + ??? This is a real kludge, but is probably the best approach short + of some very general solution. */ + +static bool +contains_save_expr_p (tree exp) +{ + switch (TREE_CODE (exp)) + { + case SAVE_EXPR: + return true; + + case ADDR_EXPR: case INDIRECT_REF: + case COMPONENT_REF: + CASE_CONVERT: case VIEW_CONVERT_EXPR: + return contains_save_expr_p (TREE_OPERAND (exp, 0)); + + case CONSTRUCTOR: + { + tree value; + unsigned HOST_WIDE_INT ix; + + FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), ix, value) + if (contains_save_expr_p (value)) + return true; + return false; + } + + default: + return false; + } +} + +/* See if EXP contains a NULL_EXPR in an expression we use for sizes. Return + it if so. This is used to detect types whose sizes involve computations + that are known to raise Constraint_Error. */ + +static tree +contains_null_expr (tree exp) +{ + tree tem; + + if (TREE_CODE (exp) == NULL_EXPR) + return exp; + + switch (TREE_CODE_CLASS (TREE_CODE (exp))) + { + case tcc_unary: + return contains_null_expr (TREE_OPERAND (exp, 0)); + + case tcc_comparison: + case tcc_binary: + tem = contains_null_expr (TREE_OPERAND (exp, 0)); + if (tem) + return tem; + + return contains_null_expr (TREE_OPERAND (exp, 1)); + + case tcc_expression: + switch (TREE_CODE (exp)) + { + case SAVE_EXPR: + return contains_null_expr (TREE_OPERAND (exp, 0)); + + case COND_EXPR: + tem = contains_null_expr (TREE_OPERAND (exp, 0)); + if (tem) + return tem; + + tem = contains_null_expr (TREE_OPERAND (exp, 1)); + if (tem) + return tem; + + return contains_null_expr (TREE_OPERAND (exp, 2)); + + default: + return 0; + } + + default: + return 0; + } +} + +/* Return an expression tree representing an equality comparison of + A1 and A2, two objects of ARRAY_TYPE. The returned expression 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 (tree result_type, tree a1, tree a2) +{ + tree t1 = TREE_TYPE (a1); + tree t2 = TREE_TYPE (a2); + tree result = convert (result_type, integer_one_node); + tree a1_is_null = convert (result_type, integer_zero_node); + tree a2_is_null = convert (result_type, integer_zero_node); + bool length_zero_p = false; + + /* Process each dimension separately and compare the lengths. If any + dimension has a size known to be zero, set SIZE_ZERO_P to 1 to + suppress the comparison of the data. */ + while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE) + { + tree lb1 = TYPE_MIN_VALUE (TYPE_DOMAIN (t1)); + tree ub1 = TYPE_MAX_VALUE (TYPE_DOMAIN (t1)); + tree lb2 = TYPE_MIN_VALUE (TYPE_DOMAIN (t2)); + tree ub2 = TYPE_MAX_VALUE (TYPE_DOMAIN (t2)); + tree bt = get_base_type (TREE_TYPE (lb1)); + tree length1 = fold_build2 (MINUS_EXPR, bt, ub1, lb1); + tree length2 = fold_build2 (MINUS_EXPR, bt, ub2, lb2); + tree nbt; + tree tem; + tree comparison, this_a1_is_null, this_a2_is_null; + + /* If the length of the first array is a constant, swap our operands + unless the length of the second array is the constant zero. + Note that we have set the `length' values to the length - 1. */ + if (TREE_CODE (length1) == INTEGER_CST + && !integer_zerop (fold_build2 (PLUS_EXPR, bt, length2, + convert (bt, integer_one_node)))) + { + 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; + } + + /* If the length of this dimension in the second array is the constant + zero, we can just go inside the original bounds for the first + array and see if last < first. */ + if (integer_zerop (fold_build2 (PLUS_EXPR, bt, length2, + convert (bt, integer_one_node)))) + { + tree ub = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1))); + tree lb = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1))); + + comparison = build_binary_op (LT_EXPR, result_type, ub, lb); + comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1); + length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1); + + length_zero_p = true; + this_a1_is_null = comparison; + this_a2_is_null = convert (result_type, integer_one_node); + } + + /* If the length is some other constant value, we know that the + this dimension in the first array cannot be superflat, so we + can just use its length from the actual stored bounds. */ + else if (TREE_CODE (length2) == INTEGER_CST) + { + ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1))); + lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1))); + ub2 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2))); + lb2 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2))); + nbt = get_base_type (TREE_TYPE (ub1)); + + comparison + = build_binary_op (EQ_EXPR, result_type, + build_binary_op (MINUS_EXPR, nbt, ub1, lb1), + build_binary_op (MINUS_EXPR, nbt, ub2, lb2)); + + /* Note that we know that UB2 and LB2 are constant and hence + cannot contain a PLACEHOLDER_EXPR. */ + + comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1); + length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1); + + this_a1_is_null = build_binary_op (LT_EXPR, result_type, ub1, lb1); + this_a2_is_null = convert (result_type, integer_zero_node); + } + + /* Otherwise compare the computed lengths. */ + else + { + length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1); + length2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length2, a2); + + comparison + = build_binary_op (EQ_EXPR, result_type, length1, length2); + + this_a1_is_null + = build_binary_op (LT_EXPR, result_type, length1, + convert (bt, integer_zero_node)); + this_a2_is_null + = build_binary_op (LT_EXPR, result_type, length2, + convert (bt, integer_zero_node)); + } + + 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 size of some bound 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)); + + if (type) + a1 = convert (type, a1), a2 = convert (type, a2); + + result = build_binary_op (TRUTH_ANDIF_EXPR, result_type, result, + fold_build2 (EQ_EXPR, result_type, a1, a2)); + + } + + /* 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 either operand contains SAVE_EXPRs, they have to be evaluated before + starting the comparison above since the place it would be otherwise + evaluated would be wrong. */ + + if (contains_save_expr_p (a1)) + result = build2 (COMPOUND_EXPR, result_type, a1, result); + + if (contains_save_expr_p (a2)) + result = build2 (COMPOUND_EXPR, result_type, a2, result); + + return result; +} + +/* 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 node so we ensure it can be modified to make it modular. */ + op_type = copy_node (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) + { + tree div_type = copy_node (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 = save_expr (result); + result = fold_build3 (COND_EXPR, op_type, + fold_build2 (LT_EXPR, integer_type_node, result, + convert (op_type, integer_zero_node)), + fold_build2 (PLUS_EXPR, op_type, result, modulus), + result); + } + + /* For the other operations, subtract the modulus if we are >= it. */ + else + { + result = save_expr (result); + result = fold_build3 (COND_EXPR, op_type, + fold_build2 (GE_EXPR, integer_type_node, + result, modulus), + fold_build2 (MINUS_EXPR, op_type, + result, modulus), + result); + } + + return convert (type, result); +} + +/* 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 MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0 + in which case the type to be used will be derived from the operands. + + 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) +{ + 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 + && !AGGREGATE_TYPE_P (operation_type) + && TYPE_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 MODIFY_EXPR: + /* 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 array and 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 (TREE_TYPE + (TREE_OPERAND (left_operand, 0))) + || POINTER_TYPE_P (TREE_TYPE + (TREE_OPERAND (left_operand, 0))))) + || (((TREE_CODE (left_type) == RECORD_TYPE + && !TYPE_JUSTIFIED_MODULAR_P (left_type)) + || TREE_CODE (left_type) == ARRAY_TYPE) + && ((TREE_CODE (TREE_TYPE + (TREE_OPERAND (left_operand, 0))) + == RECORD_TYPE) + || (TREE_CODE (TREE_TYPE + (TREE_OPERAND (left_operand, 0))) + == ARRAY_TYPE)) + && (TYPE_MODE (right_type) == BLKmode + || (TYPE_MODE (left_type) + == TYPE_MODE (TREE_TYPE + (TREE_OPERAND + (left_operand, 0)))))))) + { + 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 that is assigned a constructor, in order to + avoid putting a VIEW_CONVERT_EXPR on the LHS. But don't do this if + we wouldn't have actually copied anything. */ + else if (TREE_CODE (left_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (left_type) + && TREE_CONSTANT (TYPE_SIZE (left_type)) + && ((TREE_CODE (right_operand) == COMPONENT_REF + && TREE_CODE (TREE_TYPE (TREE_OPERAND (right_operand, 0))) + == RECORD_TYPE + && TYPE_IS_PADDING_P + (TREE_TYPE (TREE_OPERAND (right_operand, 0))) + && gnat_types_compatible_p + (left_type, + TREE_TYPE (TREE_OPERAND (right_operand, 0)))) + || TREE_CODE (right_operand) == CONSTRUCTOR) + && !integer_zerop (TYPE_SIZE (right_type))) + operation_type = left_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 if (!operation_type) + 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 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 (TREE_TYPE + (TREE_OPERAND (result, 0)))) + && (TYPE_MODE (TREE_TYPE + (TREE_OPERAND (result, 0))) + == TYPE_MODE (restype))) + || 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 + || 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); + } + + /* Then convert the right operand to its base type. This will + prevent unneeded signedness conversions when sizetype is wider than + integer. */ + right_operand = convert (right_base_type, right_operand); + right_operand = convert (TYPE_DOMAIN (left_type), right_operand); + + if (!TREE_CONSTANT (right_operand) + || !TREE_CONSTANT (TYPE_MIN_VALUE (right_type))) + gnat_mark_addressable (left_operand); + + modulus = NULL_TREE; + break; + + case GE_EXPR: + case LE_EXPR: + case GT_EXPR: + case LT_EXPR: + gcc_assert (!POINTER_TYPE_P (left_type)); + + /* ... fall through ... */ + + case EQ_EXPR: + case NE_EXPR: + /* 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 (result_type, left_operand, right_operand); + + if (op_code == NE_EXPR) + result = invert_truthvalue (result); + else + gcc_assert (op_code == EQ_EXPR); + + return result; + } + + /* Otherwise, the base types must be the same unless the objects are + fat pointers or records. If we have records, use the best type and + convert both operands to that type. */ + if (left_base_type != right_base_type) + { + if (TYPE_FAT_POINTER_P (left_base_type) + && TYPE_FAT_POINTER_P (right_base_type) + && TYPE_MAIN_VARIANT (left_base_type) + == TYPE_MAIN_VARIANT (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 these are permitted to be the same is if both + types have the same name. In that case, one of them must + not be self-referential. Use that one as the best type. + Even better is if one is of 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); + } + + /* If we are comparing a fat pointer against zero, we need to + just compare the data pointer. */ + else if (TYPE_FAT_POINTER_P (left_base_type) + && TREE_CODE (right_operand) == CONSTRUCTOR + && integer_zerop (VEC_index (constructor_elt, + CONSTRUCTOR_ELTS (right_operand), + 0) + ->value)) + { + right_operand = build_component_ref (left_operand, NULL_TREE, + TYPE_FIELDS (left_base_type), + false); + left_operand = convert (TREE_TYPE (right_operand), + integer_zero_node); + } + else + { + left_operand = convert (left_base_type, left_operand); + right_operand = convert (right_base_type, right_operand); + } + + modulus = NULL_TREE; + break; + + case PREINCREMENT_EXPR: + case PREDECREMENT_EXPR: + case POSTINCREMENT_EXPR: + case POSTDECREMENT_EXPR: + /* In these, the result type and the left operand type should be the + same. Do the operation in the base type of those and convert the + right operand (which is an integer) to that type. + + Note that these operations are only used in loop control where + we guarantee that no overflow can occur. So nothing special need + be done for modular types. */ + + gcc_assert (left_type == result_type); + operation_type = get_base_type (result_type); + left_operand = convert (operation_type, left_operand); + right_operand = convert (operation_type, right_operand); + has_side_effects = true; + 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 TRUTH_ANDIF_EXPR: + case TRUTH_ORIF_EXPR: + case TRUTH_AND_EXPR: + case TRUTH_OR_EXPR: + case TRUTH_XOR_EXPR: + left_operand = gnat_truthvalue_conversion (left_operand); + right_operand = gnat_truthvalue_conversion (right_operand); + goto common; + + 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; + + 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 = fold (build4 (op_code, operation_type, left_operand, + right_operand, NULL_TREE, NULL_TREE)); + else + result + = fold_build2 (op_code, operation_type, left_operand, right_operand); + + TREE_SIDE_EFFECTS (result) |= has_side_effects; + TREE_CONSTANT (result) + |= (TREE_CONSTANT (left_operand) & TREE_CONSTANT (right_operand) + && op_code != ARRAY_REF && op_code != ARRAY_RANGE_REF); + + if ((op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF) + && TYPE_VOLATILE (operation_type)) + TREE_THIS_VOLATILE (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) + result = fold_build2 (FLOOR_MOD_EXPR, operation_type, result, + convert (operation_type, 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; + bool 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 + && !AGGREGATE_TYPE_P (operation_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_assert (result_type == base_type); + result = invert_truthvalue (gnat_truthvalue_conversion (operand)); + 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 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) + { + HOST_WIDE_INT bitsize; + HOST_WIDE_INT bitpos; + tree offset, inner; + enum machine_mode mode; + int unsignedp, volatilep; + + inner = get_inner_reference (operand, &bitsize, &bitpos, &offset, + &mode, &unsignedp, &volatilep, + false); + + /* 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 (TREE_CODE (TREE_TYPE (inner)) == RECORD_TYPE + && TYPE_IS_PADDING_P (TREE_TYPE (inner)) + && (CONTAINS_PLACEHOLDER_P + (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS + (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; + + if (bitpos % BITS_PER_UNIT != 0) + post_error + ("taking address of object not aligned on storage unit?", + error_gnat_node); + + offset = size_binop (PLUS_EXPR, offset, + size_int (bitpos / BITS_PER_UNIT)); + + /* Take the address of INNER, convert the offset to void *, and + add then. It will later be converted to the desired result + type, if any. */ + inner = build_unary_op (ADDR_EXPR, NULL_TREE, inner); + inner = convert (ptr_void_type_node, inner); + result = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node, + inner, offset); + result = convert (build_pointer_type (TREE_TYPE (operand)), + result); + 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 (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type)) + { + result = (VEC_index (constructor_elt, + CONSTRUCTOR_ELTS (operand), + 0) + ->value); + + result = convert (build_pointer_type (TREE_TYPE (operand)), + build_unary_op (ADDR_EXPR, NULL_TREE, result)); + 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 is + contains a template, take the address of the template. */ + if (TREE_CODE (type) == RECORD_TYPE + && 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); + } + + if (type != error_mark_node) + operation_type = build_pointer_type (type); + + gnat_mark_addressable (operand); + result = fold_build1 (ADDR_EXPR, operation_type, operand); + } + + TREE_CONSTANT (result) = staticp (operand) || TREE_CONSTANT (operand); + break; + + case INDIRECT_REF: + /* If we want to refer to an entire unconstrained array, + make up an expression to do so. This will never survive to + the backend. If TYPE is a thin pointer, first convert the + operand to a fat pointer. */ + if (TYPE_THIN_POINTER_P (type) + && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))) + { + operand + = convert (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))), + operand); + type = TREE_TYPE (operand); + } + + if (TYPE_FAT_POINTER_P (type)) + { + result = build1 (UNCONSTRAINED_ARRAY_REF, + TYPE_UNCONSTRAINED_ARRAY (type), operand); + TREE_READONLY (result) = TREE_STATIC (result) + = TYPE_READONLY (TYPE_UNCONSTRAINED_ARRAY (type)); + } + else if (TREE_CODE (operand) == ADDR_EXPR) + result = TREE_OPERAND (operand, 0); + + else + { + result = fold_build1 (op_code, TREE_TYPE (type), operand); + TREE_READONLY (result) = TYPE_READONLY (TREE_TYPE (type)); + } + + side_effects + = (!TYPE_FAT_POINTER_P (type) && TYPE_VOLATILE (TREE_TYPE (type))); + 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, + convert (operation_type, + integer_one_node)))) + 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, + integer_type_node, + operand, + convert + (operation_type, + integer_zero_node)), + 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, + convert (operation_type, + integer_one_node)); + + 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 (side_effects) + { + TREE_SIDE_EFFECTS (result) = 1; + if (TREE_CODE (result) == INDIRECT_REF) + TREE_THIS_VOLATILE (result) = TYPE_VOLATILE (TREE_TYPE (result)); + } + + 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) +{ + tree result; + bool addr_p = false; + + /* The front-end verifies 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 our result. */ + if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE + || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type))) + { + addr_p = true; + 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); + } + + result = fold_build3 (COND_EXPR, result_type, condition_operand, + true_operand, false_operand); + + /* If either operand is a SAVE_EXPR (possibly surrounded by + arithmetic, make sure it gets done. */ + true_operand = skip_simple_arithmetic (true_operand); + false_operand = skip_simple_arithmetic (false_operand); + + if (TREE_CODE (true_operand) == SAVE_EXPR) + result = build2 (COMPOUND_EXPR, result_type, true_operand, result); + + if (TREE_CODE (false_operand) == SAVE_EXPR) + result = build2 (COMPOUND_EXPR, result_type, false_operand, result); + + /* ??? Seems the code above is wrong, as it may move ahead of the COND + SAVE_EXPRs with side effects and not shared by both arms. */ + + if (addr_p) + result = build_unary_op (INDIRECT_REF, NULL_TREE, result); + + return result; +} + +/* Similar, but for RETURN_EXPR. If RESULT_DECL is non-zero, build + a RETURN_EXPR around the assignment of RET_VAL to RESULT_DECL. + If RESULT_DECL is zero, build a bare RETURN_EXPR. */ + +tree +build_return_expr (tree result_decl, tree ret_val) +{ + tree result_expr; + + if (result_decl) + { + /* The gimplifier explicitly enforces the following invariant: + + RETURN_EXPR + | + MODIFY_EXPR + / \ + / \ + RESULT_DECL ... + + As a consequence, type-homogeneity dictates that we use the type + of the RESULT_DECL as the operation type. */ + + tree operation_type = TREE_TYPE (result_decl); + + /* Convert the right operand to the operation type. Note that + it's the same transformation as in the MODIFY_EXPR case of + build_binary_op with the additional guarantee that the type + cannot involve a placeholder, since otherwise the function + would use the "target pointer" return mechanism. */ + + if (operation_type != TREE_TYPE (ret_val)) + ret_val = convert (operation_type, ret_val); + + result_expr + = build2 (MODIFY_EXPR, operation_type, result_decl, ret_val); + } + else + result_expr = NULL_TREE; + + return build1 (RETURN_EXPR, void_type_node, result_expr); +} + +/* Build a CALL_EXPR to call FUNDECL with one argument, ARG. Return + the CALL_EXPR. */ + +tree +build_call_1_expr (tree fundecl, tree arg) +{ + tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)), + build_unary_op (ADDR_EXPR, NULL_TREE, fundecl), + 1, arg); + TREE_SIDE_EFFECTS (call) = 1; + return call; +} + +/* Build a CALL_EXPR to call FUNDECL with two arguments, ARG1 & ARG2. Return + the CALL_EXPR. */ + +tree +build_call_2_expr (tree fundecl, tree arg1, tree arg2) +{ + tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)), + build_unary_op (ADDR_EXPR, NULL_TREE, fundecl), + 2, arg1, arg2); + TREE_SIDE_EFFECTS (call) = 1; + return call; +} + +/* Likewise to call FUNDECL with no arguments. */ + +tree +build_call_0_expr (tree fundecl) +{ + /* We rely on build_call_nary to compute TREE_SIDE_EFFECTS. This makes + it possible to propagate DECL_IS_PURE on parameterless functions. */ + tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)), + build_unary_op (ADDR_EXPR, NULL_TREE, fundecl), + 0); + return call; +} + +/* Call a function that raises an exception and pass the line number and file + name, if requested. MSG says which exception function to call. + + GNAT_NODE is the gnat node conveying the source location for which the + error should be signaled, or Empty in which case the error is signaled on + the current ref_file_name/input_line. + + KIND says which kind of exception this is for + (N_Raise_{Constraint,Storage,Program}_Error). */ + +tree +build_call_raise (int msg, Node_Id gnat_node, char kind) +{ + tree fndecl = gnat_raise_decls[msg]; + tree label = get_exception_label (kind); + tree filename; + int line_number; + const char *str; + int len; + + /* If this is to be done as a goto, handle that case. */ + if (label) + { + Entity_Id local_raise = Get_Local_Raise_Call_Entity (); + tree gnu_result = build1 (GOTO_EXPR, void_type_node, label); + + /* If Local_Raise is present, generate + Local_Raise (exception'Identity); */ + if (Present (local_raise)) + { + tree gnu_local_raise + = gnat_to_gnu_entity (local_raise, NULL_TREE, 0); + tree gnu_exception_entity + = gnat_to_gnu_entity (Get_RT_Exception_Entity (msg), NULL_TREE, 0); + tree gnu_call + = build_call_1_expr (gnu_local_raise, + build_unary_op (ADDR_EXPR, NULL_TREE, + gnu_exception_entity)); + + gnu_result = build2 (COMPOUND_EXPR, void_type_node, + gnu_call, gnu_result);} + + return gnu_result; + } + + str + = (Debug_Flag_NN || Exception_Locations_Suppressed) + ? "" + : (gnat_node != Empty && Sloc (gnat_node) != No_Location) + ? IDENTIFIER_POINTER + (get_identifier (Get_Name_String + (Debug_Source_Name + (Get_Source_File_Index (Sloc (gnat_node)))))) + : ref_filename; + + len = strlen (str) + 1; + filename = build_string (len, str); + line_number + = (gnat_node != Empty && Sloc (gnat_node) != No_Location) + ? Get_Logical_Line_Number (Sloc(gnat_node)) : input_line; + + TREE_TYPE (filename) + = build_array_type (char_type_node, + build_index_type (build_int_cst (NULL_TREE, len))); + + return + build_call_2_expr (fndecl, + build1 (ADDR_EXPR, build_pointer_type (char_type_node), + filename), + build_int_cst (NULL_TREE, line_number)); +} + +/* 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_tree const elmt1 = * (const_tree const *) rt1; + const_tree const elmt2 = * (const_tree const *) rt2; + const_tree const field1 = TREE_PURPOSE (elmt1); + const_tree const field2 = TREE_PURPOSE (elmt2); + 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 list is LIST. */ + +tree +gnat_build_constructor (tree type, tree list) +{ + tree elmt; + int n_elmts; + bool allconstant = (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST); + bool side_effects = false; + tree result; + + /* 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 (n_elmts = 0, elmt = list; elmt; elmt = TREE_CHAIN (elmt), n_elmts ++) + { + if (!TREE_CONSTANT (TREE_VALUE (elmt)) + || (TREE_CODE (type) == RECORD_TYPE + && DECL_BIT_FIELD (TREE_PURPOSE (elmt)) + && TREE_CODE (TREE_VALUE (elmt)) != INTEGER_CST) + || !initializer_constant_valid_p (TREE_VALUE (elmt), + TREE_TYPE (TREE_VALUE (elmt)))) + allconstant = false; + + if (TREE_SIDE_EFFECTS (TREE_VALUE (elmt))) + side_effects = true; + + /* Propagate an NULL_EXPR from the size of the type. We won't ever + be executing the code we generate here in that case, but handle it + specially to avoid the compiler blowing up. */ + if (TREE_CODE (type) == RECORD_TYPE + && (0 != (result + = contains_null_expr (DECL_SIZE (TREE_PURPOSE (elmt)))))) + return build1 (NULL_EXPR, type, TREE_OPERAND (result, 0)); + } + + /* 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) + { + /* Fill an array with an element tree per index, and ask qsort to order + them according to what a bitpos comparison function says. */ + tree *gnu_arr = (tree *) alloca (sizeof (tree) * n_elmts); + int i; + + for (i = 0, elmt = list; elmt; elmt = TREE_CHAIN (elmt), i++) + gnu_arr[i] = elmt; + + qsort (gnu_arr, n_elmts, sizeof (tree), compare_elmt_bitpos); + + /* Then reconstruct the list from the sorted array contents. */ + list = NULL_TREE; + for (i = n_elmts - 1; i >= 0; i--) + { + TREE_CHAIN (gnu_arr[i]) = list; + list = gnu_arr[i]; + } + } + + result = build_constructor_from_list (type, list); + TREE_CONSTANT (result) = TREE_STATIC (result) = allconstant; + TREE_SIDE_EFFECTS (result) = side_effects; + TREE_READONLY (result) = TYPE_READONLY (type) || allconstant; + return result; +} + +/* Return a COMPONENT_REF to access a field that is given by COMPONENT, + an IDENTIFIER_NODE giving the name of the field, or FIELD, a FIELD_DECL, + for the field. Don't fold the result if NO_FOLD_P is true. + + We also handle the fact that we might have been passed a pointer to the + actual record and know how to look for fields in variant parts. */ + +static tree +build_simple_component_ref (tree record_variable, tree component, + tree field, bool no_fold_p) +{ + tree record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_variable)); + tree ref, inner_variable; + + gcc_assert ((TREE_CODE (record_type) == RECORD_TYPE + || TREE_CODE (record_type) == UNION_TYPE + || TREE_CODE (record_type) == QUAL_UNION_TYPE) + && TYPE_SIZE (record_type) + && (component != 0) != (field != 0)); + + /* If no field was specified, look for a field with the specified name + in the current record only. */ + if (!field) + for (field = TYPE_FIELDS (record_type); field; + field = TREE_CHAIN (field)) + if (DECL_NAME (field) == component) + break; + + if (!field) + return NULL_TREE; + + /* If this field is not in the specified record, see if we can find + something in the record whose original field is the same as this one. */ + if (DECL_CONTEXT (field) != record_type) + /* Check if there is a field with name COMPONENT in the record. */ + { + tree new_field; + + /* First loop thru normal components. */ + + for (new_field = TYPE_FIELDS (record_type); new_field; + new_field = TREE_CHAIN (new_field)) + if (field == new_field + || DECL_ORIGINAL_FIELD (new_field) == field + || new_field == DECL_ORIGINAL_FIELD (field) + || (DECL_ORIGINAL_FIELD (field) + && (DECL_ORIGINAL_FIELD (field) + == DECL_ORIGINAL_FIELD (new_field)))) + break; + + /* Next, loop thru DECL_INTERNAL_P components if we haven't found + the component in the first search. Doing this search in 2 steps + is required to avoiding hidden homonymous fields in the + _Parent field. */ + + if (!new_field) + for (new_field = TYPE_FIELDS (record_type); new_field; + new_field = TREE_CHAIN (new_field)) + if (DECL_INTERNAL_P (new_field)) + { + tree field_ref + = build_simple_component_ref (record_variable, + NULL_TREE, new_field, no_fold_p); + ref = build_simple_component_ref (field_ref, NULL_TREE, field, + no_fold_p); + + if (ref) + return ref; + } + + field = new_field; + } + + if (!field) + return NULL_TREE; + + /* If the field's offset has overflowed, do not attempt 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 NULL_TREE; + + /* Look through conversion between type variants. Note that this + is transparent as far as the field is concerned. */ + if (TREE_CODE (record_variable) == VIEW_CONVERT_EXPR + && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (record_variable, 0))) + == record_type) + inner_variable = TREE_OPERAND (record_variable, 0); + else + inner_variable = record_variable; + + ref = build3 (COMPONENT_REF, TREE_TYPE (field), inner_variable, field, + NULL_TREE); + + if (TREE_READONLY (record_variable) || TREE_READONLY (field)) + TREE_READONLY (ref) = 1; + if (TREE_THIS_VOLATILE (record_variable) || TREE_THIS_VOLATILE (field) + || TYPE_VOLATILE (record_type)) + TREE_THIS_VOLATILE (ref) = 1; + + if (no_fold_p) + 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. */ + else if (TREE_CODE (record_variable) == CONSTRUCTOR + && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (record_variable))) + { + VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (record_variable); + unsigned HOST_WIDE_INT idx; + tree index, value; + FOR_EACH_CONSTRUCTOR_ELT (elts, idx, index, value) + if (index == field) + return value; + return ref; + } + + else + return fold (ref); +} + +/* Like build_simple_component_ref, except that we give an error if the + reference could not be found. */ + +tree +build_component_ref (tree record_variable, tree component, + tree field, bool no_fold_p) +{ + tree ref = build_simple_component_ref (record_variable, component, field, + no_fold_p); + + if (ref) + return ref; + + /* If FIELD was specified, assume this is an invalid user field so + raise constraint error. Otherwise, we can't find the type to return, so + abort. */ + gcc_assert (field); + return build1 (NULL_EXPR, TREE_TYPE (field), + build_call_raise (CE_Discriminant_Check_Failed, Empty, + N_Raise_Constraint_Error)); +} + +/* 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 size of the object in bytes and ALIGN is the alignment in + bits. GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the + storage pool to use. If not preset, malloc and free will be used except + if GNAT_PROC is the "fake" value of -1, in which case we allocate the + object dynamically on the stack frame. */ + +tree +build_call_alloc_dealloc (tree gnu_obj, tree gnu_size, unsigned align, + Entity_Id gnat_proc, Entity_Id gnat_pool, + Node_Id gnat_node) +{ + tree gnu_align = size_int (align / BITS_PER_UNIT); + + gnu_size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_size, gnu_obj); + + if (Present (gnat_proc)) + { + /* The storage pools are obviously always tagged types, but the + secondary stack uses the same mechanism and is not tagged */ + if (Is_Tagged_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_proc = gnat_to_gnu (gnat_proc); + tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc); + tree gnu_pool = gnat_to_gnu (gnat_pool); + tree gnu_pool_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_pool); + tree gnu_call; + + 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_nary (TREE_TYPE (TREE_TYPE (gnu_proc)), + gnu_proc_addr, 4, gnu_pool_addr, + gnu_obj, gnu_size, gnu_align); + else + gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)), + gnu_proc_addr, 3, gnu_pool_addr, + gnu_size, gnu_align); + TREE_SIDE_EFFECTS (gnu_call) = 1; + return gnu_call; + } + + /* 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); + tree gnu_proc = gnat_to_gnu (gnat_proc); + tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc); + tree gnu_call; + + 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_nary (TREE_TYPE (TREE_TYPE (gnu_proc)), + gnu_proc_addr, 2, gnu_obj, gnu_size); + else + gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)), + gnu_proc_addr, 1, gnu_size); + TREE_SIDE_EFFECTS (gnu_call) = 1; + return gnu_call; + } + } + + else if (gnu_obj) + return build_call_1_expr (free_decl, gnu_obj); + + /* ??? For now, disable variable-sized allocators in the stack since + we can't yet gimplify an ALLOCATE_EXPR. */ + else if (gnat_pool == -1 + && TREE_CODE (gnu_size) == INTEGER_CST && !flag_stack_check) + { + /* If the size is a constant, we can put it in the fixed portion of + the stack frame to avoid the need to adjust the stack pointer. */ + if (TREE_CODE (gnu_size) == INTEGER_CST && !flag_stack_check) + { + tree gnu_range + = build_range_type (NULL_TREE, size_one_node, gnu_size); + tree gnu_array_type = build_array_type (char_type_node, gnu_range); + tree gnu_decl + = create_var_decl (get_identifier ("RETVAL"), NULL_TREE, + gnu_array_type, NULL_TREE, false, false, false, + false, NULL, gnat_node); + + return convert (ptr_void_type_node, + build_unary_op (ADDR_EXPR, NULL_TREE, gnu_decl)); + } + else + gcc_unreachable (); +#if 0 + return build2 (ALLOCATE_EXPR, ptr_void_type_node, gnu_size, gnu_align); +#endif + } + else + { + if (Nkind (gnat_node) != N_Allocator || !Comes_From_Source (gnat_node)) + Check_No_Implicit_Heap_Alloc (gnat_node); + + /* If the allocator size is 32bits but the pointer size is 64bits then + allocate 32bit memory (sometimes necessary on 64bit VMS). Otherwise + default to standard malloc. */ + if (UI_To_Int (Esize (Etype (gnat_node))) == 32 && POINTER_SIZE == 64) + return build_call_1_expr (malloc32_decl, gnu_size); + else + return build_call_1_expr (malloc_decl, gnu_size); + } +} + +/* Build a GCC tree to correspond 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 type of pointer. Return the tree. + 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 violations 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 = TYPE_SIZE_UNIT (type); + tree result; + unsigned int default_allocator_alignment + = get_target_default_allocator_alignment () * BITS_PER_UNIT; + + /* 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 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_FAT_OR_THIN_POINTER_P (result_type)) + { + tree storage_type + = build_unc_object_type_from_ptr (result_type, type, + get_identifier ("ALLOC")); + tree template_type = TREE_TYPE (TYPE_FIELDS (storage_type)); + tree storage_ptr_type = build_pointer_type (storage_type); + tree storage; + tree template_cons = NULL_TREE; + + size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (storage_type), + init); + + /* If the size overflows, pass -1 so the allocator will raise + storage error. */ + if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size)) + size = ssize_int (-1); + + storage = build_call_alloc_dealloc (NULL_TREE, size, + TYPE_ALIGN (storage_type), + gnat_proc, gnat_pool, gnat_node); + storage = convert (storage_ptr_type, protect_multiple_eval (storage)); + + if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type)) + { + type = TREE_TYPE (TYPE_FIELDS (type)); + + if (init) + init = convert (type, init); + } + + /* If there is an initializing expression, 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) + { + template_cons = tree_cons (TREE_CHAIN (TYPE_FIELDS (storage_type)), + init, NULL_TREE); + template_cons = tree_cons (TYPE_FIELDS (storage_type), + build_template (template_type, type, + init), + template_cons); + + return convert + (result_type, + build2 (COMPOUND_EXPR, storage_ptr_type, + build_binary_op + (MODIFY_EXPR, storage_type, + build_unary_op (INDIRECT_REF, NULL_TREE, + convert (storage_ptr_type, storage)), + gnat_build_constructor (storage_type, template_cons)), + convert (storage_ptr_type, storage))); + } + else + return build2 + (COMPOUND_EXPR, result_type, + build_binary_op + (MODIFY_EXPR, template_type, + build_component_ref + (build_unary_op (INDIRECT_REF, NULL_TREE, + convert (storage_ptr_type, storage)), + NULL_TREE, TYPE_FIELDS (storage_type), 0), + build_template (template_type, type, NULL_TREE)), + convert (result_type, convert (storage_ptr_type, storage))); + } + + /* 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 use + the maximum size. */ + if (CONTAINS_PLACEHOLDER_P (size)) + { + if (!ignore_init_type && init) + size = substitute_placeholder_in_expr (size, init); + else + size = max_size (size, true); + } + + /* If the size overflows, pass -1 so the allocator will raise + storage error. */ + if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size)) + size = ssize_int (-1); + + /* If this is in the default storage pool and the type alignment is larger + than what the default allocator supports, make an "aligning" record type + with room to store a pointer before the field, allocate an object of that + type, store the system's allocator return value just in front of the + field and return the field's address. */ + + if (No (gnat_proc) && TYPE_ALIGN (type) > default_allocator_alignment) + { + /* Construct the aligning type with enough room for a pointer ahead + of the field, then allocate. */ + tree record_type + = make_aligning_type (type, TYPE_ALIGN (type), size, + default_allocator_alignment, + POINTER_SIZE / BITS_PER_UNIT); + + tree record, record_addr; + + record_addr + = build_call_alloc_dealloc (NULL_TREE, TYPE_SIZE_UNIT (record_type), + default_allocator_alignment, Empty, Empty, + gnat_node); + + record_addr + = convert (build_pointer_type (record_type), + save_expr (record_addr)); + + record = build_unary_op (INDIRECT_REF, NULL_TREE, record_addr); + + /* Our RESULT (the Ada allocator's value) is the super-aligned address + of the internal record field ... */ + result + = build_unary_op (ADDR_EXPR, NULL_TREE, + build_component_ref + (record, NULL_TREE, TYPE_FIELDS (record_type), 0)); + result = convert (result_type, result); + + /* ... with the system allocator's return value stored just in + front. */ + { + tree ptr_addr + = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node, + convert (ptr_void_type_node, result), + size_int (-POINTER_SIZE/BITS_PER_UNIT)); + + tree ptr_ref + = convert (build_pointer_type (ptr_void_type_node), ptr_addr); + + result + = build2 (COMPOUND_EXPR, TREE_TYPE (result), + build_binary_op (MODIFY_EXPR, NULL_TREE, + build_unary_op (INDIRECT_REF, NULL_TREE, + ptr_ref), + convert (ptr_void_type_node, + record_addr)), + result); + } + } + else + result = convert (result_type, + build_call_alloc_dealloc (NULL_TREE, size, + TYPE_ALIGN (type), + gnat_proc, + gnat_pool, + gnat_node)); + + /* If we have an initial value, put the new address into a SAVE_EXPR, assign + the value, and return the address. Do this with a COMPOUND_EXPR. */ + + if (init) + { + result = save_expr (result); + result + = build2 (COMPOUND_EXPR, TREE_TYPE (result), + build_binary_op + (MODIFY_EXPR, NULL_TREE, + build_unary_op (INDIRECT_REF, + TREE_TYPE (TREE_TYPE (result)), result), + init), + result); + } + + return convert (result_type, result); +} + +/* Fill in a VMS descriptor for EXPR and return a constructor for it. + GNAT_FORMAL is how we find the descriptor record. */ + +tree +fill_vms_descriptor (tree expr, Entity_Id gnat_formal) +{ + tree record_type = TREE_TYPE (TREE_TYPE (get_gnu_tree (gnat_formal))); + tree field; + tree const_list = NULL_TREE; + + expr = maybe_unconstrained_array (expr); + gnat_mark_addressable (expr); + + for (field = TYPE_FIELDS (record_type); field; field = TREE_CHAIN (field)) + const_list + = tree_cons (field, + convert (TREE_TYPE (field), + SUBSTITUTE_PLACEHOLDER_IN_EXPR + (DECL_INITIAL (field), expr)), + const_list); + + return gnat_build_constructor (record_type, nreverse (const_list)); +} + +/* Indicate that we need to make the address of EXPR_NODE and it therefore + should not be allocated in a register. Returns true if successful. */ + +bool +gnat_mark_addressable (tree expr_node) +{ + while (1) + switch (TREE_CODE (expr_node)) + { + 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: + expr_node = TREE_OPERAND (expr_node, 0); + break; + + case CONSTRUCTOR: + TREE_ADDRESSABLE (expr_node) = 1; + return true; + + case VAR_DECL: + case PARM_DECL: + case RESULT_DECL: + TREE_ADDRESSABLE (expr_node) = 1; + return true; + + case FUNCTION_DECL: + TREE_ADDRESSABLE (expr_node) = 1; + return true; + + case CONST_DECL: + return (DECL_CONST_CORRESPONDING_VAR (expr_node) + && (gnat_mark_addressable + (DECL_CONST_CORRESPONDING_VAR (expr_node)))); + default: + return true; + } +} |