1 /*****************************************************************************/
5 /* Parse assignments */
9 /* (C) 2002-2003 Ullrich von Bassewitz */
10 /* Römerstrasse 52 */
11 /* D-70794 Filderstadt */
12 /* EMail: uz@cc65.org */
15 /* This software is provided 'as-is', without any expressed or implied */
16 /* warranty. In no event will the authors be held liable for any damages */
17 /* arising from the use of this software. */
19 /* Permission is granted to anyone to use this software for any purpose, */
20 /* including commercial applications, and to alter it and redistribute it */
21 /* freely, subject to the following restrictions: */
23 /* 1. The origin of this software must not be misrepresented; you must not */
24 /* claim that you wrote the original software. If you use this software */
25 /* in a product, an acknowledgment in the product documentation would be */
26 /* appreciated but is not required. */
27 /* 2. Altered source versions must be plainly marked as such, and must not */
28 /* be misrepresented as being the original software. */
29 /* 3. This notice may not be removed or altered from any source */
32 /*****************************************************************************/
43 #include "assignment.h"
47 /*****************************************************************************/
49 /*****************************************************************************/
53 int Assignment (ExprDesc* lval)
54 /* Parse an assignment */
58 type* ltype = lval->Type;
61 /* Check for assignment to const */
62 if (IsQualConst (ltype)) {
63 Error ("Assignment to const");
66 /* cc65 does not have full support for handling structs by value. Since
67 * assigning structs is one of the more useful operations from this
68 * family, allow it here.
70 if (IsClassStruct (ltype)) {
72 /* Get the size of the left hand side. */
73 unsigned Size = SizeOf (ltype);
75 /* If the size is that of a basic type (char, int, long), we will copy
76 * the struct using the primary register, otherwise we use memcpy. In
77 * the former case, push the address only if really needed.
82 case SIZEOF_CHAR: stype = type_uchar; break;
83 case SIZEOF_INT: stype = type_uint; break;
84 case SIZEOF_LONG: stype = type_ulong; break;
85 default: stype = ltype; UseReg = 0; break;
90 ExprLoad (0, 0, lval);
91 g_push (CF_PTR | CF_UNSIGNED, 0);
94 /* Get the expression on the right of the '=' into the primary */
97 /* Check for equality of the structs */
98 if (TypeCmp (ltype, lval2.Type) < TC_STRICT_COMPATIBLE) {
99 Error ("Incompatible types");
102 /* Check if the right hand side is an lvalue */
104 /* We have an lvalue. Do we copy using the primary? */
106 /* Just use the replacement type */
109 /* Load the value into the primary */
110 ExprLoad (CF_FORCECHAR, k, &lval2);
112 /* Store it into the new location */
117 /* We will use memcpy. Push the address of the rhs */
118 ExprLoad (0, 0, &lval2);
120 /* Push the address (or whatever is in ax in case of errors) */
121 g_push (CF_PTR | CF_UNSIGNED, 0);
123 /* Load the size of the struct into the primary */
124 g_getimmed (CF_INT | CF_UNSIGNED | CF_CONST, CheckedSizeOf (ltype), 0);
126 /* Call the memcpy function */
127 g_call (CF_FIXARGC, "memcpy", 4);
132 /* We have an rvalue. This can only happen if a function returns
133 * a struct, since there is no other way to generate an expression
134 * that as a struct as an rvalue result. We allow only 1, 2, and 4
135 * byte sized structs and do direct assignment.
141 /* Print a diagnostic */
142 Error ("Structs of this size are not supported");
143 /* Adjust the stack so we won't run in an internal error later */
151 /* Get the address on stack if needed */
154 /* Read the expression on the right side of the '=' */
157 /* Do type conversion if necessary */
158 k = TypeConversion (&lval2, k, ltype);
160 /* If necessary, load the value into the primary register */
161 ExprLoad (CF_NONE, k, &lval2);
163 /* Generate a store instruction */
168 /* Value is still in primary and not an lvalue */
169 lval->Flags = E_MEXPR;