case_equals.c

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/*****************************************************************************
 * ugBASIC - an isomorphic BASIC language compiler for retrocomputers        *
 *****************************************************************************
 * Copyright 2021-2026 Marco Spedaletti (asimov@mclink.it)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *----------------------------------------------------------------------------
 * Concesso in licenza secondo i termini della Licenza Apache, versione 2.0
 * (la "Licenza"); è proibito usare questo file se non in conformità alla
 * Licenza. Una copia della Licenza è disponibile all'indirizzo:
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Se non richiesto dalla legislazione vigente o concordato per iscritto,
 * il software distribuito nei termini della Licenza è distribuito
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/****************************************************************************
 * INCLUDE SECTION 
 ****************************************************************************/
 
#include "../../ugbc.h"
 
/****************************************************************************
 * CODE SECTION 
 ****************************************************************************/
 
/* <usermanual>
@keyword CASE
 
@english
 
The ''CASE'' command is part of ''SELECT...ENDSELECT'' construct. Each ''CASE'' 
represents a possible value of the expression. After each case, you can insert 
the statements that will be executed if the value of the expression matches that case.
The code will be executed up to the ''ENDSELECT'' instruction, another ''CASE''
instruction and, finally, when a ''CASE ELSE'' is matched.
 
@italian
 
Il comando ''CASE'' fa parte del costrutto ''SELECT...ENDSELECT''. Ogni ''CASE'' 
rappresenta un possibile valore dell'espressione. Dopo ogni caso, puoi inserire 
le istruzioni che verranno eseguite se il valore dell'espressione corrisponde 
a quel caso. Il codice verrà eseguito fino all'istruzione ''ENDSELECT'', 
un'altra istruzione ''CASE'' e, infine, quando viene trovato un ''CASE ELSE''.
 
@syntax CASE value
 
@example SELECT CASE answer
@example    CASE 42
@example       PRINT "The answer!"
@example    CASE ELSE
@example       PRINT "I am still thinking..."
@example ENDSELECT
 
@seeAlso SELECT CASE
@seeAlso CASE ELSE
@seeAlso ENDSELECT
 
</usermanual> */
void case_equals_label( Environment * _environment ) {
 
    Conditional * conditional = _environment->conditionals;
 
    if ( ! conditional ) {
        CRITICAL_CASE_WITHOUT_SELECT_CASE();
    }
 
    if ( conditional->type != CT_SELECT_CASE ) {
        CRITICAL_CASE_WITHOUT_SELECT_CASE();
    }
 
    char endselectLabel[MAX_TEMPORARY_STORAGE]; sprintf(endselectLabel, "%sf", conditional->label );
    char elseLabel[MAX_TEMPORARY_STORAGE]; sprintf(elseLabel, "%se%d", conditional->label, conditional->index );
 
    if ( conditional->index > 0 ) {
        cpu_jump( _environment, endselectLabel );
    }
 
    cpu_label( _environment, elseLabel );
 
}

void case_equals_var( Environment * _environment, char * _value ) {
 
    Conditional * conditional = _environment->conditionals;
 
    if ( ! conditional ) {
        CRITICAL_CASE_WITHOUT_SELECT_CASE();
    }
 
    if ( conditional->type != CT_SELECT_CASE ) {
        CRITICAL_CASE_WITHOUT_SELECT_CASE();
    }
 
    Variable * value = variable_retrieve_or_define( _environment, _value, VT_BYTE, 0 );
 
    char thenLabel[MAX_TEMPORARY_STORAGE]; sprintf(thenLabel, "%st%d", conditional->label, conditional->index );
    char elseLabel[MAX_TEMPORARY_STORAGE]; sprintf(elseLabel, "%se%d", conditional->label, conditional->index );
 
    ++conditional->index;
    sprintf(elseLabel, "%se%d", conditional->label, conditional->index );
 
    Variable * result;
    if ( value->initializedByConstant ) {
        result = variable_compare_const( _environment, conditional->expression->name, value->value );
    } else {
        result = variable_compare( _environment, conditional->expression->name, value->name );
    }
 
    cpu_bveq( _environment, result->realName, elseLabel );
 
    cpu_label( _environment, thenLabel );
 
}

void case_equals( Environment * _environment, int _value ) {
 
    Conditional * conditional = _environment->conditionals;
 
    if ( ! conditional ) {
        CRITICAL_CASE_WITHOUT_SELECT_CASE();
    }
 
    if ( conditional->type != CT_SELECT_CASE ) {
        CRITICAL_CASE_WITHOUT_SELECT_CASE();
    }
 
    char thenLabel[MAX_TEMPORARY_STORAGE]; sprintf(thenLabel, "%st%d", conditional->label, conditional->index );
    char elseLabel[MAX_TEMPORARY_STORAGE]; sprintf(elseLabel, "%se%d", conditional->label, conditional->index );
 
    Variable * result = variable_temporary( _environment, VT_BYTE, "(comparing)");
 
    ++conditional->index;
    sprintf(elseLabel, "%se%d", conditional->label, conditional->index );
 
    switch( VT_BITWIDTH( conditional->expression->type ) ) {
        case 8:
            cpu_compare_and_branch_8bit_const( _environment, conditional->expression->realName, _value, elseLabel, 0 );
            break;
        case 16:
            cpu_compare_and_branch_16bit_const( _environment, conditional->expression->realName, _value, elseLabel, 0 );
            break;
        case 32:
            cpu_compare_and_branch_32bit_const( _environment, conditional->expression->realName, _value, elseLabel, 0 );
            break;
        default:
            CRITICAL_CANNOT_COMPARE_WITH_CASE( conditional->expression->name );
    }
 
    cpu_label( _environment, thenLabel );
 
}