ref: a9a164fa5ed865bd5cbb9eac45b7a09b60e09812
dir: /cc1/expr.c/
/* See LICENSE file for copyright and license details. */ static char sccsid[] = "@(#) ./cc1/expr.c"; #include <assert.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <cstd.h> #include "../inc/cc.h" #include "cc1.h" #define XCHG(lp, rp, np) (np = lp, lp = rp, rp = np) static Node *xexpr(void), *xassign(void); int cmpnode(Node *np, TUINT val) { Symbol *sym; Type *tp; TUINT mask, nodeval; if (!np || !(np->flags & NCONST) || !np->sym) return 0; sym = np->sym; tp = sym->type; switch (tp->op) { case PTR: case INT: mask = (val > 1) ? ones(np->type->size) : -1; nodeval = (tp->prop & TSIGNED) ? sym->u.i : sym->u.u; return (nodeval & mask) == (val & mask); case FLOAT: return sym->u.f == val; } return 0; } static Node * promote(Node *np) { Type *tp; Node *new; struct limits *lim, *ilim; tp = np->type; switch (tp->op) { case ENUM: case INT: if (tp->n.rank >= inttype->n.rank) return np; lim = getlimits(tp); ilim = getlimits(inttype); tp = (lim->max.i <= ilim->max.i) ? inttype : uinttype; break; case FLOAT: /* TODO: Add support for C99 float math */ tp = doubletype; break; default: abort(); } if ((new = convert(np, tp, 1)) != NULL) return new; return np; } static void arithconv(Node **p1, Node **p2) { int to = 0, s1, s2; unsigned r1, r2; Type *tp1, *tp2; Node *np1, *np2; struct limits *lp1, *lp2; np1 = promote(*p1); np2 = promote(*p2); tp1 = np1->type; tp2 = np2->type; if (tp1 == tp2) goto set_p1_p2; s1 = (tp1->prop & TSIGNED) != 0; r1 = tp1->n.rank; lp1 = getlimits(tp1); s2 = (tp2->prop & TSIGNED) != 0; r2 = tp2->n.rank; lp2 = getlimits(tp2); if (s1 == s2 || tp1->op == FLOAT || tp2->op == FLOAT) { to = r1 - r2; } else if (!s1) { if (r1 >= r2 || lp1->max.i >= lp2->max.i) to = 1; else to = -1; } else { if (r2 >= r1 || lp2->max.i >= lp1->max.i) to = -1; else to = 1; } if (to > 0) np2 = convert(np2, tp1, 1); else if (to < 0) np1 = convert(np1, tp2, 1); set_p1_p2: *p1 = np1; *p2 = np2; } static int null(Node *np) { if (!(np->flags&NCONST) || np->type != pvoidtype) return 0; return cmpnode(np, 0); } static Node * chkternary(Node *yes, Node *no) { /* * FIXME: * We are ignoring type qualifiers here, * but the standard has strong rules about this. * take a look to 6.5.15 */ if (!eqtype(yes->type, no->type, 1)) { if ((yes->type->prop & TARITH) && (no->type->prop & TARITH)) { arithconv(&yes, &no); } else if (yes->type->op != PTR && no->type->op != PTR) { goto wrong_type; } else { /* convert integer 0 to NULL */ if ((yes->type->prop & TINTEGER) && cmpnode(yes, 0)) yes = convert(yes, pvoidtype, 0); if ((no->type->prop & TINTEGER) && cmpnode(no, 0)) no = convert(no, pvoidtype, 0); /* * At this point the type of both should be * a pointer to something, or we have don't * compatible types */ if (yes->type->op != PTR || no->type->op != PTR) goto wrong_type; /* * If we have a null pointer constant then * convert to the another type */ if (null(yes)) yes = convert(yes, no->type, 0); if (null(no)) no = convert(no, yes->type, 0); if (!eqtype(yes->type, no->type, 1)) goto wrong_type; } } return node(OCOLON, yes->type, yes, no); wrong_type: errorp("type mismatch in conditional expression"); freetree(yes); freetree(no); return constnode(zero); } static void chklvalue(Node *np) { if (!(np->flags & NLVAL)) errorp("lvalue required in operation"); if (np->type == voidtype) errorp("invalid use of void expression"); } Node * decay(Node *np) { Node *new; Type *tp = np->type; switch (tp->op) { case ARY: tp = tp->type; if (np->op == OPTR) { new = np->left; free(np); new->type = mktype(tp, PTR, 0, NULL); return new; } case FTN: new = node(OADDR, mktype(tp, PTR, 0, NULL), np, NULL); if (np->sym && np->sym->flags & (SGLOBAL|SLOCAL|SPRIVATE)) new->flags |= NCONST; return new; default: return np; } } static Node * integerop(int op, Node *lp, Node *rp) { if (!(lp->type->prop & TINTEGER) || !(rp->type->prop & TINTEGER)) error("operator requires integer operands"); arithconv(&lp, &rp); return node(op, lp->type, lp, rp); } static Node * integeruop(int op, Node *np) { if (!(np->type->prop & TINTEGER)) error("unary operator requires integer operand"); np = promote(np); return node(op, np->type, np, NULL); } static Node * numericaluop(int op, Node *np) { if (!(np->type->prop & TARITH)) error("unary operator requires numerical operand"); np = promote(np); return node(op, np->type, np, NULL); } Node * convert(Node *np, Type *newtp, int iscast) { Type *oldtp = np->type; if (eqtype(newtp, oldtp, 0)) return np; switch (oldtp->op) { case ENUM: case INT: case FLOAT: switch (newtp->op) { case PTR: if (oldtp->op == FLOAT || !cmpnode(np, 0) && !iscast) return NULL; /* PASSTHROUGH */ case INT: case FLOAT: case ENUM: break; default: return NULL; } break; case PTR: switch (newtp->op) { case ENUM: case INT: case VOID: if (!iscast) return NULL; break; case PTR: if (eqtype(newtp, oldtp, 1) || iscast || newtp == pvoidtype || oldtp == pvoidtype) { np->type = newtp; return np; } default: return NULL; } break; default: return NULL; } return node(OCAST, newtp, np, NULL); } static Node * parithmetic(int op, Node *lp, Node *rp) { Type *tp; Node *size, *np; if (lp->type->op != PTR) XCHG(lp, rp, np); tp = rp->type; if (tp->op == PTR && !(tp->type->prop & TDEFINED)) goto incomplete; tp = lp->type; if (!(tp->type->prop & TDEFINED)) goto incomplete; size = sizeofnode(tp->type); if (op == OSUB && BTYPE(rp) == PTR) { if ((rp = convert(rp, lp->type, 0)) == NULL) goto incorrect; lp = node(OSUB, pdifftype, lp, rp); return node(ODIV, inttype, lp, size); } if (!(rp->type->prop & TINTEGER)) goto incorrect; rp = convert(promote(rp), sizettype, 0); rp = node(OMUL, sizettype, rp, size); rp = convert(rp, tp, 1); return node(op, tp, lp, rp); incomplete: errorp("invalid use of undefined type"); return lp; incorrect: errorp("incorrect arithmetic operands"); return lp; } static Node * arithmetic(int op, Node *lp, Node *rp) { Type *ltp = lp->type, *rtp = rp->type; if ((ltp->prop & TARITH) && (rtp->prop & TARITH)) { arithconv(&lp, &rp); return node(op, lp->type, lp, rp); } else if ((ltp->op == PTR || rtp->op == PTR)) { switch (op) { case OADD: case OSUB: case OA_ADD: case OA_SUB: case OINC: case ODEC: return parithmetic(op, lp, rp); } } errorp("incorrect arithmetic operands"); } static Node * pcompare(int op, Node *lp, Node *rp) { Node *np; if (lp->type->prop & TINTEGER) XCHG(lp, rp, np); else if (eqtype(lp->type, pvoidtype, 1)) XCHG(lp, rp, np); if ((np = convert(rp, lp->type, 0)) != NULL) rp = np; else errorp("incompatible types in comparison"); return convert(node(op, pvoidtype, lp, rp), inttype, 1); } static Node * compare(int op, Node *lp, Node *rp) { Type *ltp, *rtp; ltp = lp->type; rtp = rp->type; if (ltp->op == PTR || rtp->op == PTR) { return pcompare(op, rp, lp); } else if ((ltp->prop & TARITH) && (rtp->prop & TARITH)) { arithconv(&lp, &rp); return convert(node(op, lp->type, lp, rp), inttype, 1);; } else { errorp("incompatible types in comparison"); freetree(lp); freetree(rp); return constnode(zero); } } int negop(int op) { switch (op) { case OEQ: return ONE; case ONE: return OEQ; case OLT: return OGE; case OGE: return OLT; case OLE: return OGT; case OGT: return OLE; default: abort(); } return op; } static Node * exp2cond(Node *np, int neg) { if (np->type->prop & TAGGREG) { errorp("used struct/union type value where scalar is required"); return constnode(zero); } switch (np->op) { case ONEG: case OOR: case OAND: return (neg) ? node(ONEG, inttype, np, NULL) : np; case OEQ: case ONE: case OLT: case OGE: case OLE: case OGT: if (neg) np->op = negop(np->op); return np; default: return compare((neg) ? OEQ : ONE, np, constnode(zero)); } } static Node * logic(int op, Node *lp, Node *rp) { lp = exp2cond(lp, 0); rp = exp2cond(rp, 0); return node(op, inttype, lp, rp); } static Node * field(Node *np) { Symbol *sym; namespace = np->type->ns; next(); namespace = NS_IDEN; sym = yylval.sym; if (yytoken != IDEN) unexpected(); next(); if (!(np->type->prop & TAGGREG)) { errorp("request for member '%s' in something not a structure or union", yylval.sym->name); goto free_np; } if ((sym->flags & SDECLARED) == 0) { errorp("incorrect field in struct/union"); goto free_np; } np = node(OFIELD, sym->type, np, varnode(sym)); np->flags |= NLVAL; return np; free_np: freetree(np); return constnode(zero); } static Node * content(int op, Node *np) { if (BTYPE(np) != PTR) { errorp("invalid argument of memory indirection"); } else { if (np->op == OADDR) { Node *new = np->left; new->type = np->type->type; free(np); np = new; } else { np = node(op, np->type->type, np, NULL); } np->flags |= NLVAL; } return np; } static Node * array(Node *lp, Node *rp) { Type *tp; Node *np; if (!(lp->type->prop & TINTEGER) && !(rp->type->prop & TINTEGER)) error("array subscript is not an integer"); np = arithmetic(OADD, lp, rp); tp = np->type; if (tp->op != PTR) errorp("subscripted value is neither array nor pointer"); return content(OPTR, np); } static Node * assignop(int op, Node *lp, Node *rp) { if ((rp = convert(rp, lp->type, 0)) == NULL) { errorp("incompatible types when assigning"); return lp; } return node(op, lp->type, lp, rp); } static Node * incdec(Node *np, int op) { Type *tp = np->type; Node *inc; chklvalue(np); np->flags |= NEFFECT; if (!(tp->prop & TDEFINED)) { errorp("invalid use of undefined type"); return np; } else if (tp->op == PTR && !(tp->type->prop & TDEFINED)) { errorp("%s of pointer to an incomplete type", (op == OINC || op == OA_ADD) ? "increment" : "decrement"); return np; } else if (tp->op == PTR || (tp->prop & TARITH)) { inc = constnode(one); } else { errorp("wrong type argument to increment or decrement"); return np; } return arithmetic(op, np, inc); } static Node * address(int op, Node *np) { Node *new; /* * ansi c accepts & applied to a function name, and it generates * a function pointer */ if (np->op == OSYM) { if (np->type->op == FTN) return decay(np); if (np->type->op == ARY) goto dont_check_lvalue; } chklvalue(np); dont_check_lvalue: if (np->sym && (np->sym->flags & SREGISTER)) errorp("address of register variable '%s' requested", yytext); new = node(op, mktype(np->type, PTR, 0, NULL), np, NULL); if (np->sym && np->sym->flags & (SGLOBAL|SLOCAL|SPRIVATE)) new->flags |= NCONST; return new; } static Node * negation(int op, Node *np) { if (!(np->type->prop & TARITH) && np->type->op != PTR) { errorp("invalid argument of unary '!'"); return constnode(zero); } return exp2cond(np, 1); } static Symbol * notdefined(Symbol *sym) { int isdef; if (namespace == NS_CPP && !strcmp(sym->name, "defined")) { disexpand = 1; next(); expect('('); sym = yylval.sym; expect(IDEN); expect(')'); isdef = (sym->flags & SDECLARED) != 0; sym = newsym(NS_IDEN, NULL); sym->type = inttype; sym->flags |= SCONSTANT; sym->u.i = isdef; disexpand = 0; return sym; } errorp("'%s' undeclared", yytext); sym->type = inttype; return install(sym->ns, yylval.sym); } static Symbol * adjstrings(Symbol *sym) { char *s, *t; size_t len, n; Type *tp; tp = sym->type; s = sym->u.s; for (len = strlen(s);; len += n) { next(); if (yytoken != STRING) break; t = yylval.sym->u.s; n = strlen(t); s = xrealloc(s, len + n + 1); memcpy(s+len, t, n); s[len + n] = '\0'; killsym(yylval.sym); } ++len; if (tp->n.elem != len) { sym->type = mktype(chartype, ARY, len, NULL); sym->u.s = s; } return sym; } /************************************************************* * grammar functions * *************************************************************/ static Node * primary(void) { Node *np; Symbol *sym; Node *(*fun)(Symbol *); sym = yylval.sym; switch (yytoken) { case STRING: np = constnode(adjstrings(sym)); sym->flags |= SHASINIT; emit(ODECL, sym); emit(OINIT, np); return varnode(sym); case BUILTIN: fun = sym->u.fun; next(); expect('('); np = (*fun)(sym); expect(')'); /* do not call to next */ return np; case CONSTANT: np = constnode(sym); break; case IDEN: assert((sym->flags & SCONSTANT) == 0); if ((sym->flags & SDECLARED) == 0) { if (namespace == NS_CPP) { np = constnode(zero); break; } sym = notdefined(sym); } sym->flags |= SUSED; np = varnode(sym); break; default: unexpected(); } next(); return np; } static Node * arguments(Node *np) { int toomany, n, op; Node *par = NULL, *arg; Type *argtype, **targs, *tp = np->type, *rettype; if (tp->op == PTR && tp->type->op == FTN) { np = content(OPTR, np); tp = np->type; } if (tp->op != FTN) { targs = (Type *[]) {ellipsistype}; n = 1; rettype = inttype; errorp("function or function pointer expected"); } else { targs = tp->p.pars; n = tp->n.elem; rettype = tp->type; } expect('('); if (yytoken == ')') goto no_pars; toomany = 0; do { arg = xassign(); argtype = *targs; if (argtype == ellipsistype) { n = 0; switch (arg->type->op) { case INT: arg = promote(arg); break; case FLOAT: if (arg->type == floattype) arg = convert(arg, doubletype, 1); break; } par = node(OPAR, arg->type, par, arg); continue; } if (--n < 0) { if (!toomany) errorp("too many arguments in function call"); toomany = 1; continue; } ++targs; if ((arg = convert(arg, argtype, 0)) != NULL) { par = node(OPAR, arg->type, par, arg); continue; } errorp("incompatible type for argument %d in function call", tp->n.elem - n + 1); } while (accept(',')); no_pars: expect(')'); if (n > 0 && *targs != ellipsistype) errorp("too few arguments in function call"); op = (tp->prop&TELLIPSIS) ? OCALLE : OCALL; return node(op, rettype, np, par); } static Node *unary(int); static Type * typeof(Node *np) { Type *tp; if (np == NULL) unexpected(); tp = np->type; freetree(np); return tp; } static Type * sizeexp(void) { Type *tp; expect('('); switch (yytoken) { case TYPE: case TYPEIDEN: tp = typename(); break; default: tp = typeof(unary(0)); break; } expect(')'); return tp; } static Node * postfix(Node *lp) { Node *rp; for (;;) { switch (yytoken) { case '[': case DEC: case INC: case INDIR: case '.': case '(': lp = decay(lp); switch (yytoken) { case '[': next(); rp = xexpr(); expect(']'); lp = array(lp, rp); break; case DEC: case INC: lp = incdec(lp, (yytoken == INC) ? OINC : ODEC); next(); break; case INDIR: lp = content(OPTR, lp); case '.': lp = field(lp); break; case '(': lp = arguments(lp); lp->flags |= NEFFECT; break; } break; default: return lp; } } } static Node *cast(int); static Node * unary(int needdecay) { Node *(*fun)(int, Node *), *np; Symbol *sym; int op; Type *tp; int paren; switch (yytoken) { case '!': op = 0; fun = negation; break; case '+': op = OADD; fun = numericaluop; break; case '-': op = OSNEG; fun = numericaluop; break; case '~': op = OCPL; fun = integeruop; break; case '&': op = OADDR; fun = address; break; case '*': op = OPTR; fun = content; break; case SIZEOF: next(); tp = (yytoken == '(') ? sizeexp() : typeof(unary(0)); if (!(tp->prop & TDEFINED)) errorp("sizeof applied to an incomplete type"); return sizeofnode(tp); case INC: case DEC: op = (yytoken == INC) ? OA_ADD : OA_SUB; next(); np = incdec(unary(1), op); goto chk_decay; case IDEN: case TYPEIDEN: if (lexmode != CPPMODE || strcmp(yylval.sym->name, "defined")) goto call_postfix; disexpand = 1; next(); paren = accept('('); if (yytoken != IDEN && yytoken != TYPEIDEN) cpperror("operator 'defined' requires an identifier"); if (yytoken == TYPEIDEN || !(yylval.sym->flags & SDECLARED)) sym = zero; else sym = one; disexpand = 0; next(); if (paren) expect(')'); return constnode(sym); default: call_postfix: np = postfix(primary()); goto chk_decay; } next(); np = (*fun)(op, cast(op != OADDR)); chk_decay: if (needdecay) np = decay(np); return np; } static Node * cast(int needdecay) { Node *lp, *rp; Type *tp; static int nested; if (!accept('(')) return unary(needdecay); switch (yytoken) { case TQUALIFIER: case TYPE: case TYPEIDEN: tp = typename(); expect(')'); if (yytoken == '{') return initlist(tp); switch (tp->op) { case ARY: error("cast specifies an array type"); default: lp = cast(needdecay); if ((rp = convert(lp, tp, 1)) == NULL) error("bad type conversion requested"); rp->flags &= ~NLVAL; rp->flags |= lp->flags & NLVAL; } break; default: if (nested == NR_SUBEXPR) error("too many expressions nested by parentheses"); ++nested; rp = xexpr(); --nested; expect(')'); rp = postfix(rp); break; } return rp; } static Node * mul(void) { Node *np, *(*fun)(int, Node *, Node *); int op; np = cast(1); for (;;) { switch (yytoken) { case '*': op = OMUL; fun = arithmetic; break; case '/': op = ODIV; fun = arithmetic; break; case '%': op = OMOD; fun = integerop; break; default: return np; } next(); np = (*fun)(op, np, cast(1)); } } static Node * add(void) { int op; Node *np; np = mul(); for (;;) { switch (yytoken) { case '+': op = OADD; break; case '-': op = OSUB; break; default: return np; } next(); np = arithmetic(op, np, mul()); } } static Node * shift(void) { int op; Node *np; np = add(); for (;;) { switch (yytoken) { case SHL: op = OSHL; break; case SHR: op = OSHR; break; default: return np; } next(); np = integerop(op, np, add()); } } static Node * relational(void) { int op; Node *np; np = shift(); for (;;) { switch (yytoken) { case '<': op = OLT; break; case '>': op = OGT; break; case GE: op = OGE; break; case LE: op = OLE; break; default: return np; } next(); np = compare(op, np, shift()); } } static Node * eq(void) { int op; Node *np; np = relational(); for (;;) { switch (yytoken) { case EQ: op = OEQ; break; case NE: op = ONE; break; default: return np; } next(); np = compare(op, np, relational()); } } static Node * bit_and(void) { Node *np; np = eq(); while (accept('&')) np = integerop(OBAND, np, eq()); return np; } static Node * bit_xor(void) { Node *np; np = bit_and(); while (accept('^')) np = integerop(OBXOR, np, bit_and()); return np; } static Node * bit_or(void) { Node *np; np = bit_xor(); while (accept('|')) np = integerop(OBOR, np, bit_xor()); return np; } static Node * and(void) { Node *np; np = bit_or(); while (accept(AND)) np = logic(OAND, np, bit_or()); return np; } static Node * or(void) { Node *np; np = and(); while (accept(OR)) np = logic(OOR, np, and()); return np; } static Node * ternary(void) { Node *cond; cond = or(); while (accept('?')) { Node *ifyes, *ifno, *np; cond = exp2cond(cond, 0); ifyes = xexpr(); expect(':'); ifno = ternary(); np = chkternary(ifyes, ifno); cond = node(OASK, np->type, cond, np); } return cond; } static Node * xassign(void) { Node *np, *(*fun)(int , Node *, Node *); int op; np = ternary(); for (;;) { switch (yytoken) { case '=': op = OASSIGN; fun = assignop; break; case MUL_EQ: op = OA_MUL; fun = arithmetic; break; case DIV_EQ: op = OA_DIV; fun = arithmetic; break; case MOD_EQ: op = OA_MOD; fun = integerop; break; case ADD_EQ: op = OA_ADD; fun = arithmetic; break; case SUB_EQ: op = OA_SUB; fun = arithmetic; break; case SHL_EQ: op = OA_SHL; fun = integerop; break; case SHR_EQ: op = OA_SHR; fun = integerop; break; case AND_EQ: op = OA_AND; fun = integerop; break; case XOR_EQ: op = OA_XOR; fun = integerop; break; case OR_EQ: op = OA_OR; fun = integerop; break; default: return np; } chklvalue(np); np->flags |= NEFFECT; next(); np = (fun)(op, np, assign()); } } static Node * xexpr(void) { Node *lp, *rp; lp = xassign(); while (accept(',')) { rp = xassign(); lp = node(OCOMMA, rp->type, lp, rp); } return lp; } Node * assign(void) { return simplify(xassign()); } Node * constexpr(void) { Node *np; np = ternary(); if (np && np->type->op == INT) { np = simplify(convert(np, inttype, 0)); if (np->flags & NCONST) return np; } freetree(np); return NULL; } Node * expr(void) { return simplify(xexpr()); } Node * condexpr(int neg) { Node *np; np = exp2cond(xexpr(), neg); if (np->flags & NCONST) warn("conditional expression is constant"); return simplify(np); }