ref: fca65d578482bb75a341943d97153e8b5f87a457
dir: /expr.c/
#include <stdint.h> #include <stdio.h> #include "cc.h" #define SWAP(x1, x2, t) (t = x1, x1 = x2, x2 = t) Node *expr(void); static Node * primary(void) { Node *np; Symbol *sym; switch (yytoken) { case IDEN: if ((sym = yylval.sym) == NULL) error("'%s' undeclared", yytext); np = node(emitsym, sym->type, SYM(sym), 0); np->b.lvalue = 1; next(); break; case CONSTANT: next(); /* TODO: do something */ break; case '(': next(); np = expr(); expect(')'); break; default: error("unexpected '%s'", yytext); } return np; } void intconv(Node **np1, Node **np2) { } void floatconv(Node **np1, Node **np2) { } static Node * arithmetic(char op, Node *np1, Node *np2) { Node *naux; Type *tp1, *tp2, *tp3; uint8_t t1, t2, taux, lvalue = 0; tp1 = UNQUAL(np1->type), tp2 = UNQUAL(np2->type); t1 = tp1->op, t2 = tp2->op; switch (t1) { case INT: switch (t2) { case INT: if (tp1 != tp2) intconv(&np1, &np2); break; case FLOAT: SWAP(np1, np2, naux); goto int_float; case PTR: case ARY: SWAP(np1, np2, naux); SWAP(t1, t2, taux); goto pointer; default: goto incorrect; } break; case FLOAT: switch (t2) { case FLOAT: if (tp1 != tp2) floatconv(&np1, &np2); break; case INT: int_float: np2 = castcode(np2, np1->type); break; default: goto incorrect; } break; case PTR: case ARY: pointer: if (!tp1->defined) goto nocomplete; if (op != OADD && op != OSUB) goto incorrect; tp3 = tp1->type; if (t1 == ARY) tp1 = mktype(tp1->type, PTR, NULL, 0); if (t2 != INT) goto incorrect; np2 = bincode(OMUL, tp1, castcode(np2, tp1), sizeofcode(tp3)); lvalue = 1; break; default: goto incorrect; } np1 = bincode(op, tp1, np1, np2); np1->b.lvalue = lvalue; return np1; nocomplete: error("invalid use of indefined type"); incorrect: error("incorrect arithmetic operands"); } static Node * array(Node *np1, Node *np2) { Type *tp; uint8_t t1, t2; char *err; t1 = BTYPE(np1->type); t2 = BTYPE(np2->type); if (!isaddr(t1) && !isaddr(t2)) goto bad_vector; if (t1 != INT && t2 != INT) goto bad_subs; np1 = arithmetic(OADD, np1, np2); return unarycode(OARY, np1->type->type , np1); bad_vector: err = "subscripted value is neither array nor pointer nor vector"; goto error; bad_subs: err = "array subscript is not an integer"; error: error(err); } static Node * incdec(Node *np, char op) { Type *tp; char *err; if (!np->b.lvalue) goto nolvalue; tp = UNQUAL(np->type); if (isconst(np->type->op)) goto const_mod; switch (tp->op) { case PTR: if (!tp->type->defined) goto nocomplete; case INT: case FLOAT: np = unarycode(op, np->type, np); np->b.lvalue = 0; return np; default: goto bad_type; } nolvalue: err = "lvalue required in operation"; goto error; nocomplete: err = "invalid use of indefined type"; goto error; bad_type: err = "incorrect type in arithmetic operation"; goto error; const_mod: err = "const value modified"; error: error(err); } static Node * postfix(void) { Node *np1, *np2; np1 = primary(); for (;;) { switch (yytoken) { case '[': next(); np2 = expr(); np1 = array(np1, np2); expect(']'); break; case DEC: case INC: np1 = incdec(np1, (yytoken == INC) ? OPINC : OPDEC); next(); break; default: return np1; } } } static Node * unary(void) { Node *np; switch (yytoken) { case INC: case DEC: np = incdec(unary(), (yytoken == INC) ? OINC : ODEC); next(); break; default: return postfix(); } } static struct node * cast(void) { Type *tp; Node *np1, *np2; extern Type *typename(void); if (yytoken == '(') { switch(ahead()) { case TQUALIFIER: case TYPE: next(); tp = typename(); expect(')'); np1 = cast(); np2 = castcode(np1, tp); np2->b.lvalue = np1->b.lvalue; return np1; default: break; } } return unary(); } Node * expr(void) { Node *np; do np = cast(); while (yytoken == ','); return np; }