mirror of
https://github.com/cc65/cc65.git
synced 2024-06-09 22:29:35 +00:00
175 lines
6.6 KiB
C
175 lines
6.6 KiB
C
|
/*****************************************************************************/
|
||
|
/* */
|
||
|
/* assignment.c */
|
||
|
/* */
|
||
|
/* Parse assignments */
|
||
|
/* */
|
||
|
/* */
|
||
|
/* */
|
||
|
/* (C) 2002 Ullrich von Bassewitz */
|
||
|
/* Wacholderweg 14 */
|
||
|
/* D-70597 Stuttgart */
|
||
|
/* EMail: uz@cc65.org */
|
||
|
/* */
|
||
|
/* */
|
||
|
/* This software is provided 'as-is', without any expressed or implied */
|
||
|
/* warranty. In no event will the authors be held liable for any damages */
|
||
|
/* arising from the use of this software. */
|
||
|
/* */
|
||
|
/* Permission is granted to anyone to use this software for any purpose, */
|
||
|
/* including commercial applications, and to alter it and redistribute it */
|
||
|
/* freely, subject to the following restrictions: */
|
||
|
/* */
|
||
|
/* 1. The origin of this software must not be misrepresented; you must not */
|
||
|
/* claim that you wrote the original software. If you use this software */
|
||
|
/* in a product, an acknowledgment in the product documentation would be */
|
||
|
/* appreciated but is not required. */
|
||
|
/* 2. Altered source versions must be plainly marked as such, and must not */
|
||
|
/* be misrepresented as being the original software. */
|
||
|
/* 3. This notice may not be removed or altered from any source */
|
||
|
/* distribution. */
|
||
|
/* */
|
||
|
/*****************************************************************************/
|
||
|
|
||
|
|
||
|
|
||
|
/* cc65 */
|
||
|
#include "codegen.h"
|
||
|
#include "datatype.h"
|
||
|
#include "error.h"
|
||
|
#include "expr.h"
|
||
|
#include "typecmp.h"
|
||
|
#include "assignment.h"
|
||
|
|
||
|
|
||
|
|
||
|
/*****************************************************************************/
|
||
|
/* Code */
|
||
|
/*****************************************************************************/
|
||
|
|
||
|
|
||
|
|
||
|
void Assignment (ExprDesc* lval)
|
||
|
/* Parse an assignment */
|
||
|
{
|
||
|
int k;
|
||
|
ExprDesc lval2;
|
||
|
type* ltype = lval->Type;
|
||
|
|
||
|
|
||
|
/* Check for assignment to const */
|
||
|
if (IsQualConst (ltype)) {
|
||
|
Error ("Assignment to const");
|
||
|
}
|
||
|
|
||
|
/* cc65 does not have full support for handling structs by value. Since
|
||
|
* assigning structs is one of the more useful operations from this
|
||
|
* family, allow it here.
|
||
|
*/
|
||
|
if (IsClassStruct (ltype)) {
|
||
|
|
||
|
/* Get the size of the left hand side. */
|
||
|
unsigned Size = SizeOf (ltype);
|
||
|
|
||
|
/* If the size is that of a basic type (char, int, long), we will copy
|
||
|
* the struct using the primary register, otherwise we use memcpy. In
|
||
|
* the former case, push the address only if really needed.
|
||
|
*/
|
||
|
int UseReg = 1;
|
||
|
type* stype;
|
||
|
switch (Size) {
|
||
|
case SIZEOF_CHAR: stype = type_uchar; break;
|
||
|
case SIZEOF_INT: stype = type_uint; break;
|
||
|
case SIZEOF_LONG: stype = type_ulong; break;
|
||
|
default: stype = ltype; UseReg = 0; break;
|
||
|
}
|
||
|
if (UseReg) {
|
||
|
PushAddr (lval);
|
||
|
} else {
|
||
|
exprhs (0, 0, lval);
|
||
|
g_push (CF_PTR | CF_UNSIGNED, 0);
|
||
|
}
|
||
|
|
||
|
/* Get the expression on the right of the '=' into the primary */
|
||
|
k = hie1 (&lval2);
|
||
|
|
||
|
/* Check for equality of the structs */
|
||
|
if (TypeCmp (ltype, lval2.Type) < TC_STRICT_COMPATIBLE) {
|
||
|
Error ("Incompatible types");
|
||
|
}
|
||
|
|
||
|
/* Check if the right hand side is an lvalue */
|
||
|
if (k) {
|
||
|
/* We have an lvalue. Do we copy using the primary? */
|
||
|
if (UseReg) {
|
||
|
/* Just use the replacement type */
|
||
|
lval2.Type = stype;
|
||
|
|
||
|
/* Load the value into the primary */
|
||
|
exprhs (CF_FORCECHAR, k, &lval2);
|
||
|
|
||
|
/* Store it into the new location */
|
||
|
Store (lval, stype);
|
||
|
|
||
|
} else {
|
||
|
|
||
|
/* We will use memcpy. Push the address of the rhs */
|
||
|
exprhs (0, 0, &lval2);
|
||
|
|
||
|
/* Push the address (or whatever is in ax in case of errors) */
|
||
|
g_push (CF_PTR | CF_UNSIGNED, 0);
|
||
|
|
||
|
/* Load the size of the struct into the primary */
|
||
|
g_getimmed (CF_INT | CF_UNSIGNED | CF_CONST, CheckedSizeOf (ltype), 0);
|
||
|
|
||
|
/* Call the memcpy function */
|
||
|
g_call (CF_FIXARGC, "memcpy", 4);
|
||
|
}
|
||
|
|
||
|
} else {
|
||
|
|
||
|
/* We have an rvalue. This can only happen if a function returns
|
||
|
* a struct, since there is no other way to generate an expression
|
||
|
* that as a struct as an rvalue result. We allow only 1, 2, and 4
|
||
|
* byte sized structs and do direct assignment.
|
||
|
*/
|
||
|
if (UseReg) {
|
||
|
/* Do the store */
|
||
|
Store (lval, stype);
|
||
|
} else {
|
||
|
/* Print a diagnostic */
|
||
|
Error ("Structs of this size are not supported");
|
||
|
/* Adjust the stack so we won't run in an internal error later */
|
||
|
pop (CF_PTR);
|
||
|
}
|
||
|
|
||
|
}
|
||
|
|
||
|
} else {
|
||
|
|
||
|
/* Get the address on stack if needed */
|
||
|
PushAddr (lval);
|
||
|
|
||
|
/* Get the expression on the right of the '=' into the primary */
|
||
|
if (evalexpr (CF_NONE, hie1, &lval2) == 0) {
|
||
|
/* Constant expression. Adjust the types */
|
||
|
assignadjust (ltype, &lval2);
|
||
|
/* Put the value into the primary register */
|
||
|
exprhs (CF_NONE, 0, &lval2);
|
||
|
} else {
|
||
|
/* Expression is not constant and already in the primary */
|
||
|
assignadjust (ltype, &lval2);
|
||
|
}
|
||
|
|
||
|
/* Generate a store instruction */
|
||
|
Store (lval, 0);
|
||
|
|
||
|
}
|
||
|
|
||
|
/* Value is still in primary */
|
||
|
lval->Flags = E_MEXPR;
|
||
|
}
|
||
|
|
||
|
|
||
|
|