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/*

 * Copyright (c) 2002-2006 The TenDRA Project <http://www.tendra.org/>.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 * 1. Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright notice,

 *    this list of conditions and the following disclaimer in the documentation

 *    and/or other materials provided with the distribution.

 * 3. Neither the name of The TenDRA Project nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific, prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS

 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;

 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,

 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR

 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF

 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 * $Id$

 */

/*

    		 Crown Copyright (c) 1997

    This TenDRA(r) Computer Program is subject to Copyright

    owned by the United Kingdom Secretary of State for Defence

    acting through the Defence Evaluation and Research Agency

    (DERA).  It is made available to Recipients with a

    royalty-free licence for its use, reproduction, transfer

    to other parties and amendment for any purpose not excluding

    product development provided that any such use et cetera

    shall be deemed to be acceptance of the following conditions:-

        (1) Its Recipients shall ensure that this Notice is

        reproduced upon any copies or amended versions of it;

        (2) Any amended version of it shall be clearly marked to

        show both the nature of and the organisation responsible

        for the relevant amendment or amendments;

        (3) Its onward transfer from a recipient to another

        party shall be deemed to be that party's acceptance of

        these conditions;

        (4) DERA gives no warranty or assurance as to its

        quality or suitability for any purpose and DERA accepts

        no liability whatsoever in relation to any use to which

        it may be put.

*/

#include "config.h"

#include "c_types.h"

#include "exp_ops.h"

#include "id_ops.h"

#include "off_ops.h"

#include "type_ops.h"

#include "error.h"

#include "catalog.h"

#include "assign.h"

#include "basetype.h"

#include "cast.h"

#include "construct.h"

#include "convert.h"

#include "chktype.h"

#include "expression.h"

#include "identifier.h"

#include "initialise.h"

#include "literal.h"

#include "member.h"

#include "operator.h"

#include "predict.h"

#include "syntax.h"

#include "ustring.h"

/*

    CONVERT BY ASSIGNMENT

    This routine converts the expression a to the type t, as if by

    assignment.  The cases where t is a class type or a reference are

    handled elsewhere.

*/

EXP

convert_assign(TYPE t, EXP a, ERROR *err)

{

	EXP e = cast_exp(t, a, err, CAST_IMPLICIT);

	return (e);

}

/*

    CONVERT TO A CLASS TYPE BY ASSIGNMENT

    This routine converts the expression a to the class t, as if by

    assignment.  The constructors of t are ignored, only base class

    conversions and conversion operators being considered.

*/

EXP

convert_class(TYPE t, EXP a, ERROR *err)

{

	EXP e;

	TYPE s = DEREF_type(exp_type(a));

	if (IS_type_compound(s)) {

		e = cast_class_class(t, a, err, CAST_IMPLICIT, 0);

		if (!IS_NULL_exp(e)) {

			return (e);

		}

	}

	e = convert_conv(t, a, err, CAST_IMPLICIT);

	return (e);

}

/*

    CONSTRUCT A POSTFIX EXPRESSION

    This routine constructs the expressions 'a++' and 'a--'.  Note that

    in this and other assignment expressions, a cannot have array type,

    so that no bounds checks are appropriate.  The result is an rvalue.

*/

EXP

make_postfix_exp(int op, EXP a)

{

	EXP e;

	TYPE ta;

	ERROR err;

	unsigned ca;

	/* An assignment is a side effect */

	no_side_effects++;

	/* Allow for reference conversions */

	a = convert_reference(a, REF_NORMAL);

	ta = DEREF_type(exp_type(a));

	ca = type_category(&ta);

	/* Check for overloading */

#if LANGUAGE_CPP

	if (IS_TYPE_OVERLOAD(ca)) {

		if (overload_depth == 0) {

			/* Overloads as 'operator op ( a, 0 )' */

			EXP b = make_null_exp(type_sint);

			e = binary_overload(op, a, b);

			return (e);

		}

		if (IS_TYPE_CLASS(ca)) {

			goto error_lab;

		}

	}

#else

	if (IS_TYPE_CLASS(ca)) {

		goto error_lab;

	}

#endif

	/* Operand should be a modifiable lvalue */

	err = check_modifiable(ta, a);

	if (!IS_NULL_err(err)) {

		err = concat_error(err, ERR_expr_post_incr_mod(op));

		report(crt_loc, err);

		err = NULL_err;

	}

	/* Operand can be arithmetic ... */

	if (IS_TYPE_ARITH(ca)) {

		EXP b;

		TYPE t;

		TYPE tb;

		OFFSET off = NULL_off;

		/* Allow for bitfields */

		if (IS_TYPE_BITF(ca)) {

			off = decons_bitf_exp(&a);

		}

		/* Form the result */

		MAKE_exp_dummy(ta, a, LINK_NONE, off, 0, a);

		b = convert_lvalue(a);

		tb = DEREF_type(exp_type(b));

		t = promote_type(tb);

		if (IS_NULL_off(off)) {

			MAKE_exp_dummy(tb, b, LINK_NONE, NULL_off, 0, b);

			e = convert_promote(t, b);

		} else {

			b = convert_promote(t, b);

			MAKE_exp_dummy(t, b, LINK_NONE, NULL_off, 0, b);

			e = b;

			tb = t;

		}

		if (check_int_type(ta, btype_bool)) {

			/* Booleans are weird */

			unsigned v = BOOL_TRUE;

			if (op == lex_plus_Hplus) {

				report(crt_loc,

				       ERR_expr_post_incr_bool_inc(op, ta));

			} else {

				report(crt_loc,

				       ERR_expr_post_incr_bool_dec(op, ta));

				v = BOOL_FALSE;

			}

			e = make_bool_exp(v, exp_int_lit_tag);

		} else {

			/* Other types are simple */

			EXP c = make_unit_exp(t);

			if (op == lex_plus_Hplus) {

				MAKE_exp_plus(t, e, c, e);

			} else {

				MAKE_exp_minus(t, e, c, e);

			}

			e = convert_assign(ta, e, &err);

			if (!IS_NULL_err(err)) {

				err = concat_warning(err, ERR_expr_ass_conv());

				report(crt_loc, err);

			}

		}

		MAKE_exp_postinc(tb, a, b, e, e);

		return (e);

	}

	/* ... or pointer ... */

	if (IS_TYPE_PTR(ca)) {

		/* Pointer must be to complete object type */

		EXP b;

		OFFSET off;

		TYPE t = check_pointer(ta, &err);

		if (!IS_NULL_err(err)) {

			err = concat_error(err, ERR_expr_post_incr_incompl(op));

			report(crt_loc, err);

		}

		if (IS_type_top_etc(t)) {

			t = type_char;

		}

		/* Create the identities */

		MAKE_exp_dummy(ta, a, LINK_NONE, NULL_off, 0, a);

		b = convert_lvalue(a);

		ta = DEREF_type(exp_type(b));

		MAKE_exp_dummy(ta, b, LINK_NONE, NULL_off, 0, b);

		/* Form the result */

		MAKE_off_type(t, off);

		if (op == lex_minus_Hminus) {

			MAKE_off_negate(off, off);

		}

		e = make_add_ptr(ta, b, off);

		MAKE_exp_postinc(ta, a, b, e, e);

		return (e);

	}

	/* ... and nothing else */

error_lab:

	if (!IS_TYPE_ERROR(ca)) {

		report(crt_loc, ERR_expr_post_incr_op(op, ta));

	}

	e = make_error_exp(0);

	return (e);

}

/*

    CREATE A PRE-INCREMENT EXPRESSION

    This routine creates a pre-increment or assignment expression for

    the expression a of type t given by the operation b.  If a is a

    bitfield then off gives the bitfield offset.  The result is an

    lvalue in C++, but an rvalue in C.  There is a slight problem in the

    latter case when t is a bitfield: the value is not b, but

    convert_bitfield ( b ).  This conversion is left implicit, and is

    only made explicit in the TDF output routines.

*/

static EXP

make_preinc_exp(TYPE t, EXP a, EXP b, OFFSET off, int op)

{

	EXP e;

#if LANGUAGE_C

	t = rvalue_type(t);

#endif

	if (IS_NULL_off(off)) {

		/* Simple case */

		if (op == lex_assign) {

			MAKE_exp_assign(t, a, b, e);

		} else {

			MAKE_exp_preinc(t, a, b, op, e);

		}

	} else {

		/* Bitfield case */

#if LANGUAGE_C

		MAKE_exp_preinc(t, a, b, op, e);

		t = promote_type(t);

#else

		TYPE p;

		TYPE s = find_bitfield_type(t);

		MAKE_type_ptr(cv_none, s, p);

		s = lvalue_type(s);

		MAKE_exp_preinc(s, a, b, op, e);

		MAKE_exp_address(p, e, e);

		MAKE_exp_add_ptr(p, e, off, 0, e);

		MAKE_exp_indir(t, e, e);

#endif

	}

#if LANGUAGE_C

	MAKE_exp_contents(t, e, e);

#endif

	return (e);

}

/*

    CONSTRUCT A PREFIX EXPRESSION

    This routine constructs the expressions '++a' and '--a'.  The result is

    an lvalue in C++ but an rvalue in C.

*/

EXP

make_prefix_exp(int op, EXP a)

{

	EXP e;

	TYPE ta;

	ERROR err;

	unsigned ca;

	/* An assignment is a side effect */

	no_side_effects++;

	/* Allow for reference conversions */

	a = convert_reference(a, REF_NORMAL);

	ta = DEREF_type(exp_type(a));

	ca = type_category(&ta);

	/* Check for overloading */

#if LANGUAGE_CPP

	if (IS_TYPE_OVERLOAD(ca)) {

		if (overload_depth == 0) {

			/* Overloads as 'operator op ( a )' */

			e = unary_overload(op, a);

			return (e);

		}

		if (IS_TYPE_CLASS(ca)) {

			goto error_lab;

		}

	}

#else

	if (IS_TYPE_CLASS(ca)) {

		goto error_lab;

	}

#endif

	/* Operand should be a modifiable lvalue */

	err = check_modifiable(ta, a);

	if (!IS_NULL_err(err)) {

		err = concat_error(err, ERR_expr_pre_incr_mod(op));

		report(crt_loc, err);

		err = NULL_err;

	}

	/* Operand can be arithmetic ... */

	if (IS_TYPE_ARITH(ca)) {

		EXP c;

		TYPE t;

		OFFSET off = NULL_off;

		/* Booleans are weird */

		if (check_int_type(ta, btype_bool)) {

			unsigned v = BOOL_TRUE;

			if (op == lex_plus_Hplus) {

				report(crt_loc,

				       ERR_expr_pre_incr_bool_inc(op, ta));

			} else {

				report(crt_loc,

				       ERR_expr_pre_incr_bool_dec(op, ta));

				v = BOOL_FALSE;

			}

			c = make_bool_exp(v, exp_int_lit_tag);

			e = make_preinc_exp(ta, a, c, NULL_off, lex_assign);

			return (e);

		}

		/* Allow for bitfields */

		if (IS_TYPE_BITF(ca)) {

			off = decons_bitf_exp(&a);

		}

		/* Form the result */

		MAKE_exp_dummy(ta, a, LINK_NONE, off, 0, a);

		e = convert_lvalue(a);

		t = DEREF_type(exp_type(e));

		t = promote_type(t);

		e = convert_promote(t, e);

		c = make_unit_exp(t);

		if (op == lex_plus_Hplus) {

			MAKE_exp_plus(t, e, c, e);

		} else {

			MAKE_exp_minus(t, e, c, e);

		}

		e = convert_assign(ta, e, &err);

		if (!IS_NULL_err(err)) {

			err = concat_warning(err, ERR_expr_ass_conv());

			report(crt_loc, err);

		}

		e = make_preinc_exp(ta, a, e, off, op);

		return (e);

	}

	/* ... or pointer ... */

	if (IS_TYPE_PTR(ca)) {

		/* Pointer must be to complete object type */

		OFFSET off;

		TYPE t = check_pointer(ta, &err);

		if (!IS_NULL_err(err)) {

			err = concat_error(err, ERR_expr_pre_incr_incompl(op));

			report(crt_loc, err);

		}

		if (IS_type_top_etc(t)) {

			t = type_char;

		}

		/* Form the result */

		MAKE_exp_dummy(ta, a, LINK_NONE, NULL_off, 0, a);

		e = convert_lvalue(a);

		if (!IS_type_ptr(ta)) {

			ta = DEREF_type(exp_type(e));

		}

		MAKE_off_type(t, off);

		if (op == lex_minus_Hminus) {

			MAKE_off_negate(off, off);

		}

		e = make_add_ptr(ta, e, off);

		e = make_preinc_exp(ta, a, e, NULL_off, op);

		return (e);

	}

	/* ... and nothing else */

error_lab:

	if (!IS_TYPE_ERROR(ca)) {

		report(crt_loc, ERR_expr_pre_incr_op(op, ta));

	}

	e = make_error_exp(LANGUAGE_CPP);

	return (e);

}

/*

    CONSTRUCT AN ASSIGNMENT EXPRESSION

    This routine constructs the expression 'a = b'.  If c is true then

    assignment of classes is done directly rather than via an assignment

    operator.  The result is an lvalue in C++ but an rvalue in C.

*/

EXP

make_assign_exp(EXP a, EXP b, int c)

{

	EXP e;

	ERROR err;

	TYPE ta, tb;

	unsigned ca, cb;

	int to_class = 0;

	int op = lex_assign;

	OFFSET off = NULL_off;

	/* An assignment is a side effect */

	no_side_effects++;

	/* Apply reference conversion on first operand */

	a = convert_reference(a, REF_NORMAL);

	ta = DEREF_type(exp_type(a));

	ca = type_category(&ta);

	/* Apply reference conversion on second operand */

	b = convert_reference(b, REF_ASSIGN);

	tb = DEREF_type(exp_type(b));

	cb = type_category(&tb);

	/* Check for template parameters */

#if LANGUAGE_CPP

	if (IS_TYPE_TEMPL(ca) || IS_TYPE_TEMPL(cb)) {

		if (overload_depth == 0) {

			e = binary_overload(op, a, b);

			return (e);

		}

	}

#endif

	/* Check for overloading (classes only) */

	if (IS_TYPE_CLASS(ca)) {

#if LANGUAGE_CPP

		if (c == 0) {

			if (overload_depth == 0) {

				e = binary_overload(op, a, b);

				return (e);

			}

			if (!IS_TYPE_ERROR(cb)) {

				/* Find reason for failure */

				err = check_incomplete(ta);

				if (IS_NULL_err(err) && IS_type_compound(ta)) {

					CLASS_TYPE ct;

					IDENTIFIER id;

					ct = DEREF_ctype(type_compound_defn(ta));

					id = find_operator(ct, op);

					if (!IS_NULL_id(id)) {

						err = ERR_over_match_viable_none(id);

					}

				}

				err = concat_error(err, ERR_expr_ass_op(op, ta, tb));

				report(crt_loc, err);

			}

			e = make_error_exp(LANGUAGE_CPP);

			return (e);

		}

#else

		UNUSED(c);

		UNUSED(cb);

#endif

		to_class = 1;

	}

	/* First operand should be a modifiable lvalue */

	err = check_modifiable(ta, a);

	if (!IS_NULL_err(err)) {

		err = concat_error(err, ERR_expr_ass_mod(op));

		report(crt_loc, err);

	}

	/* Do operand conversion */

	err = NULL_err;

	if (to_class) {

		b = convert_none(b);

		b = convert_class(ta, b, &err);

		b = remove_temporary(b, a);

	} else {

		b = convert_assign(ta, b, &err);

	}

	if (!IS_NULL_err(err)) {

		err = concat_warning(err, ERR_expr_ass_conv());

		report(crt_loc, err);

	}

	/* Construct the result */

	if (IS_type_bitfield(ta)) {

		off = decons_bitf_exp(&a);

		MAKE_exp_dummy(ta, a, LINK_NONE, off, 0, a);

	}

	e = make_preinc_exp(ta, a, b, off, op);

	return (e);

}

/*

    CONSTRUCT A BECOMES EXPRESSION

    This routine constructs the expression 'a op b' where op is one of the

    assignment operators, '*=', '/=' etc.  The result is an lvalue in

    C++, but an rvalue in C.

*/

EXP

make_become_exp(int op, EXP a, EXP b)

{

	EXP e;

	EXP d;

	TYPE td;

	ERROR err;

	TYPE ta, tb;

	unsigned tag;

	unsigned ca, cb;

	OFFSET off = NULL_off;

	/* An assignment is a side effect */

	no_side_effects++;

	/* Apply reference conversion on first operand */

	a = convert_reference(a, REF_NORMAL);

	ta = DEREF_type(exp_type(a));

	ca = type_category(&ta);

	/* Apply reference conversion on second operand */

	b = convert_reference(b, REF_NORMAL);

	tb = DEREF_type(exp_type(b));

	cb = type_category(&tb);

	/* Allow for overloading */

#if LANGUAGE_CPP

	if (IS_TYPE_OVERLOAD(ca) || IS_TYPE_OVERLOAD(cb)) {

		if (overload_depth == 0) {

			e = binary_overload(op, a, b);

			return (e);

		}

		if (IS_TYPE_CLASS(ca)) {

			goto error_lab;

		}

	}

#else

	if (IS_TYPE_CLASS(ca)) {

		goto error_lab;

	}

#endif

	/* First operand should be a modifiable lvalue */

	err = check_modifiable(ta, a);

	if (!IS_NULL_err(err)) {

		err = concat_error(err, ERR_expr_ass_mod(op));

		report(crt_loc, err);

		err = NULL_err;

	}

	/* Allow for bitfields */

	if (IS_TYPE_BITF(ca)) {

		off = decons_bitf_exp(&a);

	}

	/* Introduce identity for assignment variable */

	td = ta;

	MAKE_exp_dummy(td, a, LINK_NONE, off, 0, d);

	a = convert_lvalue(d);

	ta = DEREF_type(exp_type(a));

	ca = type_category(&ta);

	/* Do lvalue conversions */

	if (IS_TYPE_ADDRESS(cb)) {

		b = convert_lvalue(b);

		tb = DEREF_type(exp_type(b));

		cb = type_category(&tb);

	}

	/* Weed out booleans immediately */

	if (IS_TYPE_INT(ca) && check_int_type(ta, btype_bool)) {

		report(crt_loc, ERR_expr_ass_op(op, ta, tb));

		e = make_error_exp(LANGUAGE_CPP);

		return (e);

	}

	/* Find the operation type */

	switch (op) {

	case lex_and_Heq_H1:

		tag = exp_and_tag;

		goto integral_lab;

	case lex_div_Heq:

		tag = exp_div_tag;

		goto arithmetic_lab;

	case lex_lshift_Heq:

		tag = exp_lshift_tag;

		goto shift_lab;

	case lex_minus_Heq:

		tag = exp_minus_tag;

		goto pointer_lab;

	case lex_or_Heq_H1:

		tag = exp_or_tag;

		goto integral_lab;

	case lex_plus_Heq:

		tag = exp_plus_tag;

		goto pointer_lab;

	case lex_rem_Heq:

		tag = exp_rem_tag;

		goto integral_lab;

	case lex_rshift_Heq:

		tag = exp_rshift_tag;

		goto shift_lab;

	case lex_star_Heq:

		tag = exp_mult_tag;

		goto arithmetic_lab;

	case lex_xor_Heq_H1:

		tag = exp_xor_tag;

		goto integral_lab;

	default:

		goto error_lab;

	}

integral_lab:

	/* Integral operations */

	if (IS_TYPE_INT(ca) && IS_TYPE_INT(cb)) {

		TYPE t = arith_type(ta, tb, a, b);

		a = convert_arith(t, a, op, 1);

		b = convert_arith(t, b, op, 2);

		if (op == lex_rem_Heq) {

			IGNORE check_div_exp(op, a, b);

		}

		MAKE_exp_plus_etc(tag, t, a, b, e);

		e = convert_assign(td, e, &err);

		if (!IS_NULL_err(err)) {

			err = concat_warning(err, ERR_expr_ass_conv());

			report(crt_loc, err);

		}

		e = make_preinc_exp(td, d, e, off, op);

		return (e);

	}

	goto error_lab;

arithmetic_lab:

	/* Arithmetic operations */

	if (IS_TYPE_ARITH(ca) && IS_TYPE_ARITH(cb)) {

		TYPE t = arith_type(ta, tb, a, b);

		a = convert_arith(t, a, op, 1);

		b = convert_arith(t, b, op, 2);

		if (op == lex_div_Heq) {

			IGNORE check_div_exp(op, a, b);

		}

		MAKE_exp_plus_etc(tag, t, a, b, e);

		e = convert_assign(td, e, &err);

		if (!IS_NULL_err(err)) {

			err = concat_warning(err, ERR_expr_ass_conv());

			report(crt_loc, err);

		}

		e = make_preinc_exp(td, d, e, off, op);

		return (e);

	}

	goto error_lab;

shift_lab:

	/* Shift operations */

	if (IS_TYPE_INT(ca) && IS_TYPE_INT(cb)) {

		TYPE pta = promote_type(ta);

		TYPE ptb = promote_type(tb);

		a = convert_promote(pta, a);

		b = convert_promote(ptb, b);

		IGNORE check_shift_exp(op, pta, a, b);

		MAKE_exp_plus_etc(tag, pta, a, b, e);

		e = convert_assign(td, e, &err);

		if (!IS_NULL_err(err)) {

			err = concat_warning(err, ERR_expr_ass_conv());

			report(crt_loc, err);

		}

		e = make_preinc_exp(td, d, e, off, op);

		return (e);

	}

	goto error_lab;

pointer_lab:

	/* Pointer or arithmetic operations */

	if (IS_TYPE_PTR(ca) && IS_TYPE_INT(cb)) {

		OFFSET off1;

		int neg = 0;

		TYPE t = check_pointer(ta, &err);

		if (!IS_NULL_err(err)) {

			err = concat_error(err, ERR_expr_ass_incompl(op));

			report(crt_loc, err);

		}

		if (op == lex_minus_Heq) {

			neg = 1;

		}

		off1 = make_off_mult(t, b, neg);

		e = make_add_ptr(ta, a, off1);

		e = make_preinc_exp(td, d, e, NULL_off, op);

		return (e);

	}

	goto arithmetic_lab;

error_lab:

	/* Bad operations */

	if (!IS_TYPE_ERROR(ca) && !IS_TYPE_ERROR(cb)) {

		report(crt_loc, ERR_expr_ass_op(op, ta, tb));

	}

	e = make_error_exp(LANGUAGE_CPP);

	return (e);

}