1 /*****************************************************************************/
5 /* Parse assignments */
9 /* (C) 2002 Ullrich von Bassewitz */
11 /* D-70597 Stuttgart */
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 /*****************************************************************************/
42 #include "assignment.h"
46 /*****************************************************************************/
48 /*****************************************************************************/
52 void Assignment (ExprDesc* lval)
53 /* Parse an assignment */
57 type* ltype = lval->Type;
60 /* Check for assignment to const */
61 if (IsQualConst (ltype)) {
62 Error ("Assignment to const");
65 /* cc65 does not have full support for handling structs by value. Since
66 * assigning structs is one of the more useful operations from this
67 * family, allow it here.
69 if (IsClassStruct (ltype)) {
71 /* Get the size of the left hand side. */
72 unsigned Size = SizeOf (ltype);
74 /* If the size is that of a basic type (char, int, long), we will copy
75 * the struct using the primary register, otherwise we use memcpy. In
76 * the former case, push the address only if really needed.
81 case SIZEOF_CHAR: stype = type_uchar; break;
82 case SIZEOF_INT: stype = type_uint; break;
83 case SIZEOF_LONG: stype = type_ulong; break;
84 default: stype = ltype; UseReg = 0; break;
90 g_push (CF_PTR | CF_UNSIGNED, 0);
93 /* Get the expression on the right of the '=' into the primary */
96 /* Check for equality of the structs */
97 if (TypeCmp (ltype, lval2.Type) < TC_STRICT_COMPATIBLE) {
98 Error ("Incompatible types");
101 /* Check if the right hand side is an lvalue */
103 /* We have an lvalue. Do we copy using the primary? */
105 /* Just use the replacement type */
108 /* Load the value into the primary */
109 exprhs (CF_FORCECHAR, k, &lval2);
111 /* Store it into the new location */
116 /* We will use memcpy. Push the address of the rhs */
117 exprhs (0, 0, &lval2);
119 /* Push the address (or whatever is in ax in case of errors) */
120 g_push (CF_PTR | CF_UNSIGNED, 0);
122 /* Load the size of the struct into the primary */
123 g_getimmed (CF_INT | CF_UNSIGNED | CF_CONST, CheckedSizeOf (ltype), 0);
125 /* Call the memcpy function */
126 g_call (CF_FIXARGC, "memcpy", 4);
131 /* We have an rvalue. This can only happen if a function returns
132 * a struct, since there is no other way to generate an expression
133 * that as a struct as an rvalue result. We allow only 1, 2, and 4
134 * byte sized structs and do direct assignment.
140 /* Print a diagnostic */
141 Error ("Structs of this size are not supported");
142 /* Adjust the stack so we won't run in an internal error later */
150 /* Get the address on stack if needed */
153 /* Get the expression on the right of the '=' into the primary */
154 if (evalexpr (CF_NONE, hie1, &lval2) == 0) {
155 /* Constant expression. Adjust the types */
156 assignadjust (ltype, &lval2);
157 /* Put the value into the primary register */
158 exprhs (CF_NONE, 0, &lval2);
160 /* Expression is not constant and already in the primary */
161 assignadjust (ltype, &lval2);
164 /* Generate a store instruction */
169 /* Value is still in primary */
170 lval->Flags = E_MEXPR;