/**
加减类表达式
<additive_expression>::=<multiplicative_expression>
{<TK_PLUS><multiplicative_expression>
|<TK_MINUS><multiplicative_expression>}
*/
void additive_expression(){
multiplicative_expression();
while(TK_PLUS == token || TK_MINUS == token){
get_token();
multiplicative_expression();
}
}
struct Symbol* additive_expression(struct AdditiveExpression* node)
{
if (node->type == 0)
return multiplicative_expression(node->multiplicativeExpression);
struct Symbol* symbol1 = load_symbol(additive_expression(node->additiveExpression));
struct Symbol* symbol2 = load_symbol(multiplicative_expression(node->multiplicativeExpression));
return additive_symbol(symbol1, symbol2, node->type);
}
Expression *ExpressionBuilder::multiplicative_expression()
{
Expression *value = unary_expression();
switch (next()) {
case '*':
return createBinaryExpression('*', value, multiplicative_expression());
case '%':
return createBinaryExpression('%', value, multiplicative_expression());
case '/':
return createBinaryExpression('/', value, multiplicative_expression());
default:
prev();
return value;
};
}
int additive_expression(void) {
if( multiplicative_expression() ) {
} else if( additive_expression() ) {
switch( lookaheadT.type ) {
case PLUS:
match(PLUS);
break;
case MINUS:
match(MINUS);
break;
}
multiplicative_expression();
} else {
abort();
}
}
// Parse an additive expression.
//
// additive-expression:
// multiplicative-expression:
// additive-expression '+' multiplicative-expression
// additive-expression '-' multiplicative-expression
Expr&
Parser::additive_expression()
{
Expr* e1 = &multiplicative_expression();
while (true) {
if (Token tok = match_if(tk::plus_tok)) {
Expr& e2 = multiplicative_expression();
e1 = &on_add_expression(tok, *e1, e2);
} else if (Token tok = match_if(tk::minus_tok)) {
Expr& e2 = unary_expression();
e1 = &on_sub_expression(tok, *e1, e2);
} else {
break;
}
}
return *e1;
}
struct Symbol* multiplicative_expression(struct MultiplicativeExpression* node)
{
if (node->type == 0)
return cast_expression(node->castExpression);
struct Symbol* symbol1 = load_symbol(multiplicative_expression(node->multiplicativeExpression));
struct Symbol* symbol2 = load_symbol(cast_expression(node->castExpression));
return multiplicative_symbol(symbol1, symbol2, node->type);
}
static struct block *additive_expression(struct block *block)
{
struct var value;
block = multiplicative_expression(block);
while (1) {
value = block->expr;
if (peek().token == '+') {
consume('+');
block = multiplicative_expression(block);
block->expr = eval_expr(block, IR_OP_ADD, value, block->expr);
} else if (peek().token == '-') {
consume('-');
block = multiplicative_expression(block);
block->expr = eval_expr(block, IR_OP_SUB, value, block->expr);
} else break;
}
return block;
}
int PP_Expression::multiplicative_expression()
{
int value = unary_expression();
switch (next()) {
case PP_STAR:
return value * multiplicative_expression();
case PP_PERCENT:
{
int remainder = multiplicative_expression();
return remainder ? value % remainder : 0;
}
case PP_SLASH:
{
int div = multiplicative_expression();
return div ? value / div : 0;
}
default:
prev();
return value;
};
}
int PP_Expression::additive_expression()
{
int value = multiplicative_expression();
switch (next()) {
case PP_PLUS:
return value + additive_expression();
case PP_MINUS:
return value - additive_expression();
default:
prev();
return value;
}
}
Expression *ExpressionBuilder::additive_expression()
{
Expression *value = multiplicative_expression();
switch (next()) {
case '+':
return createBinaryExpression('+', value, additive_expression());
case '-':
return createBinaryExpression('-', value, additive_expression());
default:
prev();
return value;
}
}
int multiplicative_expression(void) {
if( cast_expression() ) {
} else if ( multiplicative_expression() ) {
switch( lookaheadT.type ) {
case ASTERIX:
match(ASTERIX);
break;
case FSLASH:
match(FSLASH);
break;
case PERCENT:
match(PERCENT);
break;
}
cast_expression();
} else {
abort();
}
}