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freebsd/usr.bin/xlint/lint1/tree.c

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/* $NetBSD: tree.c,v 1.24 2002/01/31 22:30:20 tv Exp $ */
/*
* Copyright (c) 1994, 1995 Jochen Pohl
* All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Jochen Pohl for
* The NetBSD Project.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(lint)
__RCSID("$NetBSD: tree.c,v 1.24 2002/01/31 22:30:20 tv Exp $");
#endif
__FBSDID("$FreeBSD$");
#include <stdlib.h>
#include <string.h>
#include <float.h>
#include <limits.h>
#include <math.h>
#include "lint1.h"
#include "cgram.h"
/* Various flags for each operator. */
static mod_t modtab[NOPS];
static tnode_t *getinode(tspec_t, int64_t);
static void ptrcmpok(op_t, tnode_t *, tnode_t *);
static int asgntypok(op_t, int, tnode_t *, tnode_t *);
static void chkbeop(op_t, tnode_t *, tnode_t *);
static void chkeop2(op_t, int, tnode_t *, tnode_t *);
static void chkeop1(op_t, int, tnode_t *, tnode_t *);
static tnode_t *mktnode(op_t, type_t *, tnode_t *, tnode_t *);
static void balance(op_t, tnode_t **, tnode_t **);
static void incompat(op_t, tspec_t, tspec_t);
static void illptrc(mod_t *, type_t *, type_t *);
static void mrgqual(type_t **, type_t *, type_t *);
static int conmemb(type_t *);
static void ptconv(int, tspec_t, tspec_t, type_t *, tnode_t *);
static void iiconv(op_t, int, tspec_t, tspec_t, type_t *, tnode_t *);
static void piconv(op_t, tspec_t, type_t *, tnode_t *);
static void ppconv(op_t, tnode_t *, type_t *);
static tnode_t *bldstr(op_t, tnode_t *, tnode_t *);
static tnode_t *bldincdec(op_t, tnode_t *);
static tnode_t *bldamper(tnode_t *, int);
static tnode_t *bldplmi(op_t, tnode_t *, tnode_t *);
static tnode_t *bldshft(op_t, tnode_t *, tnode_t *);
static tnode_t *bldcol(tnode_t *, tnode_t *);
static tnode_t *bldasgn(op_t, tnode_t *, tnode_t *);
static tnode_t *plength(type_t *);
static tnode_t *fold(tnode_t *);
static tnode_t *foldtst(tnode_t *);
static tnode_t *foldflt(tnode_t *);
static tnode_t *chkfarg(type_t *, tnode_t *);
static tnode_t *parg(int, type_t *, tnode_t *);
static void nulleff(tnode_t *);
static void displexpr(tnode_t *, int);
static void chkaidx(tnode_t *, int);
static void chkcomp(op_t, tnode_t *, tnode_t *);
static void precconf(tnode_t *);
/*
* Initialize mods of operators.
*/
void
initmtab(void)
{
static struct {
op_t op;
mod_t m;
} imods[] = {
{ ARROW, { 1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,
"->" } },
{ POINT, { 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
"." } },
{ NOT, { 0,1,0,1,0,1,0,1,0,0,0,0,0,0,0,1,0,
"!" } },
{ COMPL, { 0,0,1,0,0,1,1,0,0,0,0,0,0,0,0,1,1,
"~" } },
{ INCBEF, { 0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,
"prefix++" } },
{ DECBEF, { 0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,
"prefix--" } },
{ INCAFT, { 0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,
"postfix++" } },
{ DECAFT, { 0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,
"postfix--" } },
{ UPLUS, { 0,0,0,0,1,1,1,0,0,0,0,0,0,0,0,1,1,
"unary +" } },
{ UMINUS, { 0,0,0,0,1,1,1,0,0,0,1,0,0,0,0,1,1,
"unary -" } },
{ STAR, { 0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,
"unary *" } },
{ AMPER, { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
"unary &" } },
{ MULT, { 1,0,0,0,1,1,1,0,1,0,0,1,0,0,0,1,1,
"*" } },
{ DIV, { 1,0,0,0,1,1,1,0,1,0,1,1,0,0,0,1,1,
"/" } },
{ MOD, { 1,0,1,0,0,1,1,0,1,0,1,1,0,0,0,1,1,
"%" } },
{ PLUS, { 1,0,0,1,0,1,1,0,1,0,0,0,0,0,0,1,0,
"+" } },
{ MINUS, { 1,0,0,1,0,1,1,0,1,0,0,0,0,0,0,1,0,
"-" } },
{ SHL, { 1,0,1,0,0,1,1,0,0,0,0,0,1,0,0,1,1,
"<<" } },
{ SHR, { 1,0,1,0,0,1,1,0,0,0,1,0,1,0,0,1,1,
">>" } },
{ LT, { 1,1,0,1,0,1,1,0,1,0,1,1,0,1,1,0,1,
"<" } },
{ LE, { 1,1,0,1,0,1,1,0,1,0,1,1,0,1,1,0,1,
"<=" } },
{ GT, { 1,1,0,1,0,1,1,0,1,0,1,1,0,1,1,0,1,
">" } },
{ GE, { 1,1,0,1,0,1,1,0,1,0,1,1,0,1,1,0,1,
">=" } },
{ EQ, { 1,1,0,1,0,1,1,0,1,0,0,0,0,1,1,0,1,
"==" } },
{ NE, { 1,1,0,1,0,1,1,0,1,0,0,0,0,1,1,0,1,
"!=" } },
{ AND, { 1,0,1,0,0,1,1,0,1,0,0,0,1,0,0,1,0,
"&" } },
{ XOR, { 1,0,1,0,0,1,1,0,1,0,0,0,1,0,0,1,0,
"^" } },
{ OR, { 1,0,1,0,0,1,1,0,1,0,0,0,1,0,0,1,0,
"|" } },
{ LOGAND, { 1,1,0,1,0,1,0,1,0,0,0,0,0,0,0,1,0,
"&&" } },
{ LOGOR, { 1,1,0,1,0,1,0,1,0,0,0,0,1,0,0,1,0,
"||" } },
{ QUEST, { 1,0,0,0,0,1,0,1,0,0,0,0,0,0,0,0,0,
"?" } },
{ COLON, { 1,0,0,0,0,0,1,0,1,0,0,0,0,0,1,0,0,
":" } },
{ ASSIGN, { 1,0,0,0,0,0,0,0,0,1,0,0,0,0,1,0,0,
"=" } },
{ MULASS, { 1,0,0,0,1,0,0,0,0,1,0,0,0,0,0,1,0,
"*=" } },
{ DIVASS, { 1,0,0,0,1,0,0,0,0,1,0,1,0,0,0,1,0,
"/=" } },
{ MODASS, { 1,0,1,0,0,0,0,0,0,1,0,1,0,0,0,1,0,
"%=" } },
{ ADDASS, { 1,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,
"+=" } },
{ SUBASS, { 1,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,
"-=" } },
{ SHLASS, { 1,0,1,0,0,0,0,0,0,1,0,0,0,0,0,1,0,
"<<=" } },
{ SHRASS, { 1,0,1,0,0,0,0,0,0,1,0,0,0,0,0,1,0,
">>=" } },
{ ANDASS, { 1,0,1,0,0,0,0,0,0,1,0,0,0,0,0,1,0,
"&=" } },
{ XORASS, { 1,0,1,0,0,0,0,0,0,1,0,0,0,0,0,1,0,
"^=" } },
{ ORASS, { 1,0,1,0,0,0,0,0,0,1,0,0,0,0,0,1,0,
"|=" } },
{ NAME, { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
"NAME" } },
{ CON, { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
"CON" } },
{ STRING, { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
"STRING" } },
{ FSEL, { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
"FSEL" } },
{ CALL, { 1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,
"CALL" } },
{ COMMA, { 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,
"," } },
{ CVT, { 0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,
"CVT" } },
{ ICALL, { 1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,
"ICALL" } },
{ LOAD, { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
"LOAD" } },
{ PUSH, { 0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,
"PUSH" } },
{ RETURN, { 1,0,0,0,0,0,0,0,0,1,0,0,0,0,1,0,0,
"RETURN" } },
{ INIT, { 1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,
"INIT" } },
{ FARG, { 1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,
"FARG" } },
{ NOOP }
};
int i;
for (i = 0; imods[i].op != NOOP; i++)
STRUCT_ASSIGN(modtab[imods[i].op], imods[i].m);
}
/*
* Increase degree of reference.
* This is most often used to change type "T" in type "pointer to T".
*/
type_t *
incref(type_t *tp, tspec_t t)
{
type_t *tp2;
tp2 = getblk(sizeof (type_t));
tp2->t_tspec = t;
tp2->t_subt = tp;
return (tp2);
}
/*
* same for use in expressions
*/
type_t *
tincref(type_t *tp, tspec_t t)
{
type_t *tp2;
tp2 = tgetblk(sizeof (type_t));
tp2->t_tspec = t;
tp2->t_subt = tp;
return (tp2);
}
/*
* Create a node for a constant.
*/
tnode_t *
getcnode(type_t *tp, val_t *v)
{
tnode_t *n;
n = getnode();
n->tn_op = CON;
n->tn_type = tp;
n->tn_val = tgetblk(sizeof (val_t));
n->tn_val->v_tspec = tp->t_tspec;
n->tn_val->v_ansiu = v->v_ansiu;
n->tn_val->v_u = v->v_u;
free(v);
return (n);
}
/*
* Create a node for a integer constant.
*/
static tnode_t *
getinode(tspec_t t, int64_t q)
{
tnode_t *n;
n = getnode();
n->tn_op = CON;
n->tn_type = gettyp(t);
n->tn_val = tgetblk(sizeof (val_t));
n->tn_val->v_tspec = t;
n->tn_val->v_quad = q;
return (n);
}
/*
* Create a node for a name (symbol table entry).
* ntok is the token which follows the name.
*/
tnode_t *
getnnode(sym_t *sym, int ntok)
{
tnode_t *n;
if (sym->s_scl == NOSCL) {
sym->s_scl = EXTERN;
sym->s_def = DECL;
if (ntok == T_LPARN) {
if (sflag) {
/* function implicitly declared to ... */
warning(215);
}
/*
* XXX if tflag is set the symbol should be
* exported to level 0
*/
sym->s_type = incref(sym->s_type, FUNC);
} else {
/* %s undefined */
error(99, sym->s_name);
}
}
if (sym->s_kind != FVFT && sym->s_kind != FMOS)
lerror("getnnode() 1");
n = getnode();
n->tn_type = sym->s_type;
if (sym->s_scl != ENUMCON) {
n->tn_op = NAME;
n->tn_sym = sym;
if (sym->s_kind == FVFT && sym->s_type->t_tspec != FUNC)
n->tn_lvalue = 1;
} else {
n->tn_op = CON;
n->tn_val = tgetblk(sizeof (val_t));
*n->tn_val = sym->s_value;
}
return (n);
}
/*
* Create a node for a string.
*/
tnode_t *
getsnode(strg_t *strg)
{
size_t len;
tnode_t *n;
len = strg->st_len;
n = getnode();
n->tn_op = STRING;
n->tn_type = tincref(gettyp(strg->st_tspec), ARRAY);
n->tn_type->t_dim = len + 1;
n->tn_lvalue = 1;
n->tn_strg = tgetblk(sizeof (strg_t));
n->tn_strg->st_tspec = strg->st_tspec;
n->tn_strg->st_len = len;
if (strg->st_tspec == CHAR) {
n->tn_strg->st_cp = tgetblk(len + 1);
(void)memcpy(n->tn_strg->st_cp, strg->st_cp, len + 1);
free(strg->st_cp);
} else {
n->tn_strg->st_wcp = tgetblk((len + 1) * sizeof (wchar_t));
(void)memcpy(n->tn_strg->st_wcp, strg->st_wcp,
(len + 1) * sizeof (wchar_t));
free(strg->st_wcp);
}
free(strg);
return (n);
}
/*
* Returns a symbol which has the same name as the msym argument and is a
* member of the struct or union specified by the tn argument.
*/
sym_t *
strmemb(tnode_t *tn, op_t op, sym_t *msym)
{
str_t *str;
type_t *tp;
sym_t *sym, *csym;
int eq;
tspec_t t;
/*
* Remove the member if it was unknown until now (Which means
* that no defined struct or union has a member with the same name).
*/
if (msym->s_scl == NOSCL) {
/* undefined struct/union member: %s */
error(101, msym->s_name);
rmsym(msym);
msym->s_kind = FMOS;
msym->s_scl = MOS;
msym->s_styp = tgetblk(sizeof (str_t));
msym->s_styp->stag = tgetblk(sizeof (sym_t));
msym->s_styp->stag->s_name = unnamed;
msym->s_value.v_tspec = INT;
return (msym);
}
/* Set str to the tag of which msym is expected to be a member. */
str = NULL;
t = (tp = tn->tn_type)->t_tspec;
if (op == POINT) {
if (t == STRUCT || t == UNION)
str = tp->t_str;
} else if (op == ARROW && t == PTR) {
t = (tp = tp->t_subt)->t_tspec;
if (t == STRUCT || t == UNION)
str = tp->t_str;
}
/*
* If this struct/union has a member with the name of msym, return
* return this it.
*/
if (str != NULL) {
for (sym = msym; sym != NULL; sym = sym->s_link) {
if (sym->s_scl != MOS && sym->s_scl != MOU)
continue;
if (sym->s_styp != str)
continue;
if (strcmp(sym->s_name, msym->s_name) != 0)
continue;
return (sym);
}
}
/*
* Set eq to 0 if there are struct/union members with the same name
* and different types and/or offsets.
*/
eq = 1;
for (csym = msym; csym != NULL; csym = csym->s_link) {
if (csym->s_scl != MOS && csym->s_scl != MOU)
continue;
if (strcmp(msym->s_name, csym->s_name) != 0)
continue;
for (sym = csym->s_link ; sym != NULL; sym = sym->s_link) {
int w;
if (sym->s_scl != MOS && sym->s_scl != MOU)
continue;
if (strcmp(csym->s_name, sym->s_name) != 0)
continue;
if (csym->s_value.v_quad != sym->s_value.v_quad) {
eq = 0;
break;
}
w = 0;
eq = eqtype(csym->s_type, sym->s_type, 0, 0, &w) && !w;
if (!eq)
break;
if (csym->s_field != sym->s_field) {
eq = 0;
break;
}
if (csym->s_field) {
type_t *tp1, *tp2;
tp1 = csym->s_type;
tp2 = sym->s_type;
if (tp1->t_flen != tp2->t_flen) {
eq = 0;
break;
}
if (tp1->t_foffs != tp2->t_foffs) {
eq = 0;
break;
}
}
}
if (!eq)
break;
}
/*
* Now handle the case in which the left operand refers really
* to a struct/union, but the right operand is not member of it.
*/
if (str != NULL) {
/* illegal member use: %s */
if (eq && tflag) {
warning(102, msym->s_name);
} else {
error(102, msym->s_name);
}
return (msym);
}
/*
* Now the left operand of ARROW does not point to a struct/union
* or the left operand of POINT is no struct/union.
*/
if (eq) {
if (op == POINT) {
/* left operand of "." must be struct/union object */
if (tflag) {
warning(103);
} else {
error(103);
}
} else {
/* left operand of "->" must be pointer to ... */
if (tflag && tn->tn_type->t_tspec == PTR) {
warning(104);
} else {
error(104);
}
}
} else {
if (tflag) {
/* non-unique member requires struct/union %s */
error(105, op == POINT ? "object" : "pointer");
} else {
/* unacceptable operand of %s */
error(111, modtab[op].m_name);
}
}
return (msym);
}
/*
* Create a tree node. Called for most operands except function calls,
* sizeof and casts.
*
* op operator
* ln left operand
* rn if not NULL, right operand
*/
tnode_t *
build(op_t op, tnode_t *ln, tnode_t *rn)
{
mod_t *mp;
tnode_t *ntn;
type_t *rtp;
mp = &modtab[op];
/* If there was an error in one of the operands, return. */
if (ln == NULL || (mp->m_binary && rn == NULL))
return (NULL);
/*
* Apply class conversions to the left operand, but only if its
* value is needed or it is compaired with null.
*/
if (mp->m_vctx || mp->m_tctx)
ln = cconv(ln);
/*
* The right operand is almost always in a test or value context,
* except if it is a struct or union member.
*/
if (mp->m_binary && op != ARROW && op != POINT)
rn = cconv(rn);
/*
* Print some warnings for comparisons of unsigned values with
* constants lower than or equal to null. This must be done
* before promote() because otherwise unsigned char and unsigned
* short would be promoted to int. Also types are tested to be
* CHAR, which would also become int.
*/
if (mp->m_comp)
chkcomp(op, ln, rn);
/*
* Promote the left operand if it is in a test or value context
*/
if (mp->m_vctx || mp->m_tctx)
ln = promote(op, 0, ln);
/*
* Promote the right operand, but only if it is no struct or
* union member, or if it is not to be assigned to the left operand
*/
if (mp->m_binary && op != ARROW && op != POINT &&
op != ASSIGN && op != RETURN) {
rn = promote(op, 0, rn);
}
/*
* If the result of the operation is different for signed or
* unsigned operands and one of the operands is signed only in
* ANSI C, print a warning.
*/
if (mp->m_tlansiu && ln->tn_op == CON && ln->tn_val->v_ansiu) {
/* ANSI C treats constant as unsigned, op %s */
warning(218, mp->m_name);
ln->tn_val->v_ansiu = 0;
}
if (mp->m_transiu && rn->tn_op == CON && rn->tn_val->v_ansiu) {
/* ANSI C treats constant as unsigned, op %s */
warning(218, mp->m_name);
rn->tn_val->v_ansiu = 0;
}
/* Make sure both operands are of the same type */
if (mp->m_balance || (tflag && (op == SHL || op == SHR)))
balance(op, &ln, &rn);
/*
* Check types for compatibility with the operation and mutual
* compatibility. Return if there are serios problems.
*/
if (!typeok(op, 0, ln, rn))
return (NULL);
/* And now create the node. */
switch (op) {
case POINT:
case ARROW:
ntn = bldstr(op, ln, rn);
break;
case INCAFT:
case DECAFT:
case INCBEF:
case DECBEF:
ntn = bldincdec(op, ln);
break;
case AMPER:
ntn = bldamper(ln, 0);
break;
case STAR:
ntn = mktnode(STAR, ln->tn_type->t_subt, ln, NULL);
break;
case PLUS:
case MINUS:
ntn = bldplmi(op, ln, rn);
break;
case SHL:
case SHR:
ntn = bldshft(op, ln, rn);
break;
case COLON:
ntn = bldcol(ln, rn);
break;
case ASSIGN:
case MULASS:
case DIVASS:
case MODASS:
case ADDASS:
case SUBASS:
case SHLASS:
case SHRASS:
case ANDASS:
case XORASS:
case ORASS:
case RETURN:
ntn = bldasgn(op, ln, rn);
break;
case COMMA:
case QUEST:
ntn = mktnode(op, rn->tn_type, ln, rn);
break;
default:
rtp = mp->m_logop ? gettyp(INT) : ln->tn_type;
if (!mp->m_binary && rn != NULL)
lerror("build() 1");
ntn = mktnode(op, rtp, ln, rn);
break;
}
/* Return if an error occurred. */
if (ntn == NULL)
return (NULL);
/* Print a warning if precedence confusion is possible */
if (mp->m_tpconf)
precconf(ntn);
/*
* Print a warning if one of the operands is in a context where
* it is compared with null and if this operand is a constant.
*/
if (mp->m_tctx) {
if (ln->tn_op == CON ||
((mp->m_binary && op != QUEST) && rn->tn_op == CON)) {
if (hflag && !ccflg)
/* constant in conditional context */
warning(161);
}
}
/* Fold if the operator requires it */
if (mp->m_fold) {
if (ln->tn_op == CON && (!mp->m_binary || rn->tn_op == CON)) {
if (mp->m_tctx) {
ntn = foldtst(ntn);
} else if (isftyp(ntn->tn_type->t_tspec)) {
ntn = foldflt(ntn);
} else {
ntn = fold(ntn);
}
} else if (op == QUEST && ln->tn_op == CON) {
ntn = ln->tn_val->v_quad ? rn->tn_left : rn->tn_right;
}
}
return (ntn);
}
/*
* Perform class conversions.
*
* Arrays of type T are converted into pointers to type T.
* Functions are converted to pointers to functions.
* Lvalues are converted to rvalues.
*/
tnode_t *
cconv(tnode_t *tn)
{
type_t *tp;
/*
* Array-lvalue (array of type T) is converted into rvalue
* (pointer to type T)
*/
if (tn->tn_type->t_tspec == ARRAY) {
if (!tn->tn_lvalue) {
/* %soperand of '%s' must be lvalue */
/* XXX print correct operator */
(void)gnuism(114, "", modtab[AMPER].m_name);
}
tn = mktnode(AMPER, tincref(tn->tn_type->t_subt, PTR),
tn, NULL);
}
/*
* Expression of type function (function with return value of type T)
* in rvalue-expression (pointer to function with return value
* of type T)
*/
if (tn->tn_type->t_tspec == FUNC)
tn = bldamper(tn, 1);
/* lvalue to rvalue */
if (tn->tn_lvalue) {
tp = tduptyp(tn->tn_type);
tp->t_const = tp->t_volatile = 0;
tn = mktnode(LOAD, tp, tn, NULL);
}
return (tn);
}
/*
* Perform most type checks. First the types are checked using
* informations from modtab[]. After that it is done by hand for
* more complicated operators and type combinations.
*
* If the types are ok, typeok() returns 1, otherwise 0.
*/
int
typeok(op_t op, int arg, tnode_t *ln, tnode_t *rn)
{
mod_t *mp;
tspec_t lt, rt = NOTSPEC, lst = NOTSPEC, rst = NOTSPEC, olt = NOTSPEC,
ort = NOTSPEC;
type_t *ltp, *rtp = NULL, *lstp = NULL, *rstp = NULL;
tnode_t *tn;
mp = &modtab[op];
if ((lt = (ltp = ln->tn_type)->t_tspec) == PTR)
lst = (lstp = ltp->t_subt)->t_tspec;
if (mp->m_binary) {
if ((rt = (rtp = rn->tn_type)->t_tspec) == PTR)
rst = (rstp = rtp->t_subt)->t_tspec;
}
if (mp->m_rqint) {
/* integertypes required */
if (!isityp(lt) || (mp->m_binary && !isityp(rt))) {
incompat(op, lt, rt);
return (0);
}
} else if (mp->m_rqsclt) {
/* scalar types required */
if (!issclt(lt) || (mp->m_binary && !issclt(rt))) {
incompat(op, lt, rt);
return (0);
}
} else if (mp->m_rqatyp) {
/* arithmetic types required */
if (!isatyp(lt) || (mp->m_binary && !isatyp(rt))) {
incompat(op, lt, rt);
return (0);
}
}
if (op == SHL || op == SHR || op == SHLASS || op == SHRASS) {
/*
* For these operations we need the types before promotion
* and balancing.
*/
for (tn=ln; tn->tn_op==CVT && !tn->tn_cast; tn=tn->tn_left)
continue;
olt = tn->tn_type->t_tspec;
for (tn=rn; tn->tn_op==CVT && !tn->tn_cast; tn=tn->tn_left)
continue;
ort = tn->tn_type->t_tspec;
}
switch (op) {
case POINT:
/*
* Most errors required by ANSI C are reported in strmemb().
* Here we only must check for totaly wrong things.
*/
if (lt == FUNC || lt == VOID || ltp->t_isfield ||
((lt != STRUCT && lt != UNION) && !ln->tn_lvalue)) {
/* Without tflag we got already an error */
if (tflag)
/* unacceptable operand of %s */
error(111, mp->m_name);
return (0);
}
/* Now we have an object we can create a pointer to */
break;
case ARROW:
if (lt != PTR && !(tflag && isityp(lt))) {
/* Without tflag we got already an error */
if (tflag)
/* unacceptabel operand of %s */
error(111, mp->m_name);
return (0);
}
break;
case INCAFT:
case DECAFT:
case INCBEF:
case DECBEF:
/* operands have scalar types (checked above) */
if (!ln->tn_lvalue) {
if (ln->tn_op == CVT && ln->tn_cast &&
ln->tn_left->tn_op == LOAD) {
/* a cast does not yield an lvalue */
error(163);
}
/* %soperand of %s must be lvalue */
error(114, "", mp->m_name);
return (0);
} else if (ltp->t_const) {
/* %soperand of %s must be modifiable lvalue */
if (!tflag)
warning(115, "", mp->m_name);
}
break;
case AMPER:
if (lt == ARRAY || lt == FUNC) {
/* ok, a warning comes later (in bldamper()) */
} else if (!ln->tn_lvalue) {
if (ln->tn_op == CVT && ln->tn_cast &&
ln->tn_left->tn_op == LOAD) {
/* a cast does not yield an lvalue */
error(163);
}
/* %soperand of %s must be lvalue */
error(114, "", mp->m_name);
return (0);
} else if (issclt(lt)) {
if (ltp->t_isfield) {
/* cannot take address of bit-field */
error(112);
return (0);
}
} else if (lt != STRUCT && lt != UNION) {
/* unacceptable operand of %s */
error(111, mp->m_name);
return (0);
}
if (ln->tn_op == NAME && ln->tn_sym->s_reg) {
/* cannot take address of register %s */
error(113, ln->tn_sym->s_name);
return (0);
}
break;
case STAR:
/* until now there were no type checks for this operator */
if (lt != PTR) {
/* cannot dereference non-pointer type */
error(96);
return (0);
}
break;
case PLUS:
/* operands have scalar types (checked above) */
if ((lt == PTR && !isityp(rt)) || (rt == PTR && !isityp(lt))) {
incompat(op, lt, rt);
return (0);
}
break;
case MINUS:
/* operands have scalar types (checked above) */
if (lt == PTR && (!isityp(rt) && rt != PTR)) {
incompat(op, lt, rt);
return (0);
} else if (rt == PTR && lt != PTR) {
incompat(op, lt, rt);
return (0);
}
if (lt == PTR && rt == PTR) {
if (!eqtype(lstp, rstp, 1, 0, NULL)) {
/* illegal pointer subtraction */
error(116);
}
}
break;
case SHR:
/* operands have integer types (checked above) */
if (pflag && !isutyp(lt)) {
/*
* The left operand is signed. This means that
* the operation is (possibly) nonportable.
*/
/* bitwise operation on signed value nonportable */
if (ln->tn_op != CON) {
/* possibly nonportable */
warning(117);
} else if (ln->tn_val->v_quad < 0) {
warning(120);
}
} else if (!tflag && !sflag && !isutyp(olt) && isutyp(ort)) {
/*
* The left operand would become unsigned in
* traditional C.
*/
if (hflag &&
(ln->tn_op != CON || ln->tn_val->v_quad < 0)) {
/* semantics of %s change in ANSI C; use ... */
warning(118, mp->m_name);
}
} else if (!tflag && !sflag && !isutyp(olt) && !isutyp(ort) &&
psize(lt) < psize(rt)) {
/*
* In traditional C the left operand would be extended,
* possibly with 1, and then shifted.
*/
if (hflag &&
(ln->tn_op != CON || ln->tn_val->v_quad < 0)) {
/* semantics of %s change in ANSI C; use ... */
warning(118, mp->m_name);
}
}
goto shift;
case SHL:
/*
* ANSI C does not perform balancing for shift operations,
* but traditional C does. If the width of the right operand
* is greather than the width of the left operand, than in
* traditional C the left operand would be extendet to the
* width of the right operand. For SHL this may result in
* different results.
*/
if (psize(lt) < psize(rt)) {
/*
* XXX If both operands are constant make sure
* that there is really a differencs between
* ANSI C and traditional C.
*/
if (hflag)
/* semantics of %s change in ANSI C; use ... */
warning(118, mp->m_name);
}
shift:
if (rn->tn_op == CON) {
if (!isutyp(rt) && rn->tn_val->v_quad < 0) {
/* negative shift */
warning(121);
} else if ((uint64_t)rn->tn_val->v_quad == size(lt)) {
/* shift equal to size fo object */
warning(267);
} else if ((uint64_t)rn->tn_val->v_quad > size(lt)) {
/* shift greater than size of object */
warning(122);
}
}
break;
case EQ:
case NE:
/*
* Accept some things which are allowed with EQ and NE,
* but not with ordered comparisons.
*/
if (lt == PTR && ((rt == PTR && rst == VOID) || isityp(rt))) {
if (rn->tn_op == CON && rn->tn_val->v_quad == 0)
break;
}
if (rt == PTR && ((lt == PTR && lst == VOID) || isityp(lt))) {
if (ln->tn_op == CON && ln->tn_val->v_quad == 0)
break;
}
/* FALLTHROUGH */
case LT:
case GT:
case LE:
case GE:
if ((lt == PTR || rt == PTR) && lt != rt) {
if (isityp(lt) || isityp(rt)) {
/* illegal comb. of pointer and int., op %s */
warning(123, mp->m_name);
} else {
incompat(op, lt, rt);
return (0);
}
} else if (lt == PTR && rt == PTR) {
ptrcmpok(op, ln, rn);
}
break;
case QUEST:
if (!issclt(lt)) {
/* first operand must have scalar type, op ? : */
error(170);
return (0);
}
if (rn->tn_op != COLON)
lerror("typeok() 2");
break;
case COLON:
if (isatyp(lt) && isatyp(rt))
break;
if (lt == STRUCT && rt == STRUCT && ltp->t_str == rtp->t_str)
break;
if (lt == UNION && rt == UNION && ltp->t_str == rtp->t_str)
break;
/* combination of any pointer and 0, 0L or (void *)0 is ok */
if (lt == PTR && ((rt == PTR && rst == VOID) || isityp(rt))) {
if (rn->tn_op == CON && rn->tn_val->v_quad == 0)
break;
}
if (rt == PTR && ((lt == PTR && lst == VOID) || isityp(lt))) {
if (ln->tn_op == CON && ln->tn_val->v_quad == 0)
break;
}
if ((lt == PTR && isityp(rt)) || (isityp(lt) && rt == PTR)) {
/* illegal comb. of ptr. and int., op %s */
warning(123, mp->m_name);
break;
}
if (lt == VOID || rt == VOID) {
if (lt != VOID || rt != VOID)
/* incompatible types in conditional */
warning(126);
break;
}
if (lt == PTR && rt == PTR && ((lst == VOID && rst == FUNC) ||
(lst == FUNC && rst == VOID))) {
/* (void *)0 handled above */
if (sflag)
/* ANSI C forbids conv. of %s to %s, op %s */
warning(305, "function pointer", "'void *'",
mp->m_name);
break;
}
if (rt == PTR && lt == PTR) {
if (!eqtype(lstp, rstp, 1, 0, NULL))
illptrc(mp, ltp, rtp);
break;
}
/* incompatible types in conditional */
error(126);
return (0);
case ASSIGN:
case INIT:
case FARG:
case RETURN:
if (!asgntypok(op, arg, ln, rn))
return (0);
goto assign;
case MULASS:
case DIVASS:
case MODASS:
goto assign;
case ADDASS:
case SUBASS:
/* operands have scalar types (checked above) */
if ((lt == PTR && !isityp(rt)) || rt == PTR) {
incompat(op, lt, rt);
return (0);
}
goto assign;
case SHLASS:
goto assign;
case SHRASS:
if (pflag && !isutyp(lt) && !(tflag && isutyp(rt))) {
/* bitwise operation on s.v. possibly nonportabel */
warning(117);
}
goto assign;
case ANDASS:
case XORASS:
case ORASS:
goto assign;
assign:
if (!ln->tn_lvalue) {
if (ln->tn_op == CVT && ln->tn_cast &&
ln->tn_left->tn_op == LOAD) {
/* a cast does not yield an lvalue */
error(163);
}
/* %soperand of %s must be lvalue */
error(114, "left ", mp->m_name);
return (0);
} else if (ltp->t_const || ((lt == STRUCT || lt == UNION) &&
conmemb(ltp))) {
/* %soperand of %s must be modifiable lvalue */
if (!tflag)
warning(115, "left ", mp->m_name);
}
break;
case COMMA:
if (!modtab[ln->tn_op].m_sideeff)
nulleff(ln);
break;
/* LINTED (enumeration values not handled in switch) */
case CON:
case CASE:
case PUSH:
case LOAD:
case ICALL:
case CVT:
case CALL:
case FSEL:
case STRING:
case NAME:
case LOGOR:
case LOGAND:
case OR:
case XOR:
case AND:
case MOD:
case DIV:
case MULT:
case UMINUS:
case UPLUS:
case DEC:
case INC:
case COMPL:
case NOT:
case NOOP:
break;
}
if (mp->m_badeop &&
(ltp->t_isenum || (mp->m_binary && rtp->t_isenum))) {
chkbeop(op, ln, rn);
} else if (mp->m_enumop && (ltp->t_isenum && rtp->t_isenum)) {
chkeop2(op, arg, ln, rn);
} else if (mp->m_enumop && (ltp->t_isenum || rtp->t_isenum)) {
chkeop1(op, arg, ln, rn);
}
return (1);
}
static void
ptrcmpok(op_t op, tnode_t *ln, tnode_t *rn)
{
type_t *ltp, *rtp;
tspec_t lt, rt;
const char *lts, *rts;
lt = (ltp = ln->tn_type)->t_subt->t_tspec;
rt = (rtp = rn->tn_type)->t_subt->t_tspec;
if (lt == VOID || rt == VOID) {
if (sflag && (lt == FUNC || rt == FUNC)) {
/* (void *)0 already handled in typeok() */
*(lt == FUNC ? &lts : &rts) = "function pointer";
*(lt == VOID ? &lts : &rts) = "'void *'";
/* ANSI C forbids comparison of %s with %s */
warning(274, lts, rts);
}
return;
}
if (!eqtype(ltp->t_subt, rtp->t_subt, 1, 0, NULL)) {
illptrc(&modtab[op], ltp, rtp);
return;
}
if (lt == FUNC && rt == FUNC) {
if (sflag && op != EQ && op != NE)
/* ANSI C forbids ordered comp. of func ptr */
warning(125);
}
}
/*
* Checks type compatibility for ASSIGN, INIT, FARG and RETURN
* and prints warnings/errors if necessary.
* If the types are (almost) compatible, 1 is returned, otherwise 0.
*/
static int
asgntypok(op_t op, int arg, tnode_t *ln, tnode_t *rn)
{
tspec_t lt, rt, lst = NOTSPEC, rst = NOTSPEC;
type_t *ltp, *rtp, *lstp = NULL, *rstp = NULL;
mod_t *mp;
const char *lts, *rts;
if ((lt = (ltp = ln->tn_type)->t_tspec) == PTR)
lst = (lstp = ltp->t_subt)->t_tspec;
if ((rt = (rtp = rn->tn_type)->t_tspec) == PTR)
rst = (rstp = rtp->t_subt)->t_tspec;
mp = &modtab[op];
if (isatyp(lt) && isatyp(rt))
return (1);
if ((lt == STRUCT || lt == UNION) && (rt == STRUCT || rt == UNION))
/* both are struct or union */
return (ltp->t_str == rtp->t_str);
/* 0, 0L and (void *)0 may be assigned to any pointer */
if (lt == PTR && ((rt == PTR && rst == VOID) || isityp(rt))) {
if (rn->tn_op == CON && rn->tn_val->v_quad == 0)
return (1);
}
if (lt == PTR && rt == PTR && (lst == VOID || rst == VOID)) {
/* two pointers, at least one pointer to void */
if (sflag && (lst == FUNC || rst == FUNC)) {
/* comb. of ptr to func and ptr to void */
*(lst == FUNC ? &lts : &rts) = "function pointer";
*(lst == VOID ? &lts : &rts) = "'void *'";
switch (op) {
case INIT:
case RETURN:
/* ANSI C forbids conversion of %s to %s */
warning(303, rts, lts);
break;
case FARG:
/* ANSI C forbids conv. of %s to %s, arg #%d */
warning(304, rts, lts, arg);
break;
default:
/* ANSI C forbids conv. of %s to %s, op %s */
warning(305, rts, lts, mp->m_name);
break;
}
}
}
if (lt == PTR && rt == PTR && (lst == VOID || rst == VOID ||
eqtype(lstp, rstp, 1, 0, NULL))) {
/* compatible pointer types (qualifiers ignored) */
if (!tflag &&
((!lstp->t_const && rstp->t_const) ||
(!lstp->t_volatile && rstp->t_volatile))) {
/* left side has not all qualifiers of right */
switch (op) {
case INIT:
case RETURN:
/* incompatible pointer types */
warning(182);
break;
case FARG:
/* argument has incompat. ptr. type, arg #%d */
warning(153, arg);
break;
default:
/* operands have incompat. ptr. types, op %s */
warning(128, mp->m_name);
break;
}
}
return (1);
}
if ((lt == PTR && isityp(rt)) || (isityp(lt) && rt == PTR)) {
switch (op) {
case INIT:
case RETURN:
/* illegal combination of pointer and integer */
warning(183);
break;
case FARG:
/* illegal comb. of ptr. and int., arg #%d */
warning(154, arg);
break;
default:
/* illegal comb. of ptr. and int., op %s */
warning(123, mp->m_name);
break;
}
return (1);
}
if (lt == PTR && rt == PTR) {
switch (op) {
case INIT:
case RETURN:
illptrc(NULL, ltp, rtp);
break;
case FARG:
/* argument has incompatible pointer type, arg #%d */
warning(153, arg);
break;
default:
illptrc(mp, ltp, rtp);
break;
}
return (1);
}
switch (op) {
case INIT:
/* initialisation type mismatch */
error(185);
break;
case RETURN:
/* return value type mismatch */
error(211);
break;
case FARG:
/* argument is incompatible with prototype, arg #%d */
warning(155, arg);
break;
default:
incompat(op, lt, rt);
break;
}
return (0);
}
/*
* Prints a warning if an operator, which should be senseless for an
* enum type, is applied to an enum type.
*/
static void
chkbeop(op_t op, tnode_t *ln, tnode_t *rn)
{
mod_t *mp;
if (!eflag)
return;
mp = &modtab[op];
if (!(ln->tn_type->t_isenum ||
(mp->m_binary && rn->tn_type->t_isenum))) {
return;
}
/*
* Enum as offset to a pointer is an exception (otherwise enums
* could not be used as array indizes).
*/
if (op == PLUS &&
((ln->tn_type->t_isenum && rn->tn_type->t_tspec == PTR) ||
(rn->tn_type->t_isenum && ln->tn_type->t_tspec == PTR))) {
return;
}
/* dubious operation on enum, op %s */
warning(241, mp->m_name);
}
/*
* Prints a warning if an operator is applied to two different enum types.
*/
static void
chkeop2(op_t op, int arg, tnode_t *ln, tnode_t *rn)
{
mod_t *mp;
mp = &modtab[op];
if (ln->tn_type->t_enum != rn->tn_type->t_enum) {
switch (op) {
case INIT:
/* enum type mismatch in initialisation */
warning(210);
break;
case FARG:
/* enum type mismatch, arg #%d */
warning(156, arg);
break;
case RETURN:
/* return value type mismatch */
warning(211);
break;
default:
/* enum type mismatch, op %s */
warning(130, mp->m_name);
break;
}
#if 0
} else if (mp->m_comp && op != EQ && op != NE) {
if (eflag)
/* dubious comparisons of enums */
warning(243, mp->m_name);
#endif
}
}
/*
* Prints a warning if an operator has both enum end other integer
* types.
*/
static void
chkeop1(op_t op, int arg, tnode_t *ln, tnode_t *rn)
{
if (!eflag)
return;
switch (op) {
case INIT:
/*
* Initializations with 0 should be allowed. Otherwise,
* we should complain about all uninitialized enums,
* consequently.
*/
if (!rn->tn_type->t_isenum && rn->tn_op == CON &&
isityp(rn->tn_type->t_tspec) && rn->tn_val->v_quad == 0) {
return;
}
/* initialisation of '%s' with '%s' */
warning(277, tyname(ln->tn_type), tyname(rn->tn_type));
break;
case FARG:
/* combination of '%s' and '%s', arg #%d */
warning(278, tyname(ln->tn_type), tyname(rn->tn_type), arg);
break;
case RETURN:
/* combination of '%s' and '%s' in return */
warning(279, tyname(ln->tn_type), tyname(rn->tn_type));
break;
default:
/* combination of '%s' and %s, op %s */
warning(242, tyname(ln->tn_type), tyname(rn->tn_type),
modtab[op].m_name);
break;
}
}
/*
* Build and initialize a new node.
*/
static tnode_t *
mktnode(op_t op, type_t *type, tnode_t *ln, tnode_t *rn)
{
tnode_t *ntn;
tspec_t t;
ntn = getnode();
ntn->tn_op = op;
ntn->tn_type = type;
ntn->tn_left = ln;
ntn->tn_right = rn;
if (op == STAR || op == FSEL) {
if (ln->tn_type->t_tspec == PTR) {
t = ln->tn_type->t_subt->t_tspec;
if (t != FUNC && t != VOID)
ntn->tn_lvalue = 1;
} else {
lerror("mktnode() 2");
}
}
return (ntn);
}
/*
* Performs usual conversion of operands to (unsigned) int.
*
* If tflag is set or the operand is a function argument with no
* type information (no prototype or variable # of args), convert
* float to double.
*/
tnode_t *
promote(op_t op, int farg, tnode_t *tn)
{
tspec_t t;
type_t *ntp;
int len;
t = tn->tn_type->t_tspec;
if (!isatyp(t))
return (tn);
if (!tflag) {
/*
* ANSI C requires that the result is always of type INT
* if INT can represent all possible values of the previous
* type.
*/
if (tn->tn_type->t_isfield) {
len = tn->tn_type->t_flen;
if (size(INT) > len) {
t = INT;
} else {
if (size(INT) != len)
lerror("promote() 1");
if (isutyp(t)) {
t = UINT;
} else {
t = INT;
}
}
} else if (t == CHAR || t == UCHAR || t == SCHAR) {
t = (size(CHAR) < size(INT) || t != UCHAR) ?
INT : UINT;
} else if (t == SHORT || t == USHORT) {
t = (size(SHORT) < size(INT) || t == SHORT) ?
INT : UINT;
} else if (t == ENUM) {
t = INT;
} else if (farg && t == FLOAT) {
t = DOUBLE;
}
} else {
/*
* In traditional C, keep unsigned and promote FLOAT
* to DOUBLE.
*/
if (t == UCHAR || t == USHORT) {
t = UINT;
} else if (t == CHAR || t == SCHAR || t == SHORT) {
t = INT;
} else if (t == FLOAT) {
t = DOUBLE;
} else if (t == ENUM) {
t = INT;
}
}
if (t != tn->tn_type->t_tspec) {
ntp = tduptyp(tn->tn_type);
ntp->t_tspec = t;
/*
* Keep t_isenum so we are later able to check compatibility
* of enum types.
*/
tn = convert(op, 0, ntp, tn);
}
return (tn);
}
/*
* Insert conversions which are necessary to give both operands the same
* type. This is done in different ways for traditional C and ANIS C.
*/
static void
balance(op_t op, tnode_t **lnp, tnode_t **rnp)
{
tspec_t lt, rt, t;
int i, u;
type_t *ntp;
static tspec_t tl[] = {
LDOUBLE, DOUBLE, FLOAT, UQUAD, QUAD, ULONG, LONG, UINT, INT,
};
lt = (*lnp)->tn_type->t_tspec;
rt = (*rnp)->tn_type->t_tspec;
if (!isatyp(lt) || !isatyp(rt))
return;
if (!tflag) {
if (lt == rt) {
t = lt;
} else if (lt == LDOUBLE || rt == LDOUBLE) {
t = LDOUBLE;
} else if (lt == DOUBLE || rt == DOUBLE) {
t = DOUBLE;
} else if (lt == FLOAT || rt == FLOAT) {
t = FLOAT;
} else {
/*
* If type A has more bits than type B it should
* be able to hold all possible values of type B.
*/
if (size(lt) > size(rt)) {
t = lt;
} else if (size(lt) < size(rt)) {
t = rt;
} else {
for (i = 3; tl[i] != INT; i++) {
if (tl[i] == lt || tl[i] == rt)
break;
}
if ((isutyp(lt) || isutyp(rt)) &&
!isutyp(tl[i])) {
i--;
}
t = tl[i];
}
}
} else {
/* Keep unsigned in traditional C */
u = isutyp(lt) || isutyp(rt);
for (i = 0; tl[i] != INT; i++) {
if (lt == tl[i] || rt == tl[i])
break;
}
t = tl[i];
if (u && isityp(t) && !isutyp(t))
t = utyp(t);
}
if (t != lt) {
ntp = tduptyp((*lnp)->tn_type);
ntp->t_tspec = t;
*lnp = convert(op, 0, ntp, *lnp);
}
if (t != rt) {
ntp = tduptyp((*rnp)->tn_type);
ntp->t_tspec = t;
*rnp = convert(op, 0, ntp, *rnp);
}
}
/*
* Insert a conversion operator, which converts the type of the node
* to another given type.
* If op is FARG, arg is the number of the argument (used for warnings).
*/
tnode_t *
convert(op_t op, int arg, type_t *tp, tnode_t *tn)
{
tnode_t *ntn;
tspec_t nt, ot, ost = NOTSPEC;
if (tn->tn_lvalue)
lerror("convert() 1");
nt = tp->t_tspec;
if ((ot = tn->tn_type->t_tspec) == PTR)
ost = tn->tn_type->t_subt->t_tspec;
if (!tflag && !sflag && op == FARG)
ptconv(arg, nt, ot, tp, tn);
if (isityp(nt) && isityp(ot)) {
iiconv(op, arg, nt, ot, tp, tn);
} else if (nt == PTR && ((ot == PTR && ost == VOID) || isityp(ot)) &&
tn->tn_op == CON && tn->tn_val->v_quad == 0) {
/* 0, 0L and (void *)0 may be assigned to any pointer. */
} else if (isityp(nt) && ot == PTR) {
piconv(op, nt, tp, tn);
} else if (nt == PTR && ot == PTR) {
ppconv(op, tn, tp);
}
ntn = getnode();
ntn->tn_op = CVT;
ntn->tn_type = tp;
ntn->tn_cast = op == CVT;
if (tn->tn_op != CON || nt == VOID) {
ntn->tn_left = tn;
} else {
ntn->tn_op = CON;
ntn->tn_val = tgetblk(sizeof (val_t));
cvtcon(op, arg, ntn->tn_type, ntn->tn_val, tn->tn_val);
}
return (ntn);
}
/*
* Print a warning if a prototype causes a type conversion that is
* different from what would happen to the same argument in the
* absence of a prototype.
*
* Errors/Warnings about illegal type combinations are already printed
* in asgntypok().
*/
static void
ptconv(int arg, tspec_t nt, tspec_t ot, type_t *tp, tnode_t *tn)
{
tnode_t *ptn;
if (!isatyp(nt) || !isatyp(ot))
return;
/*
* If the type of the formal parameter is char/short, a warning
* would be useless, because functions declared the old style
* can't expect char/short arguments.
*/
if (nt == CHAR || nt == UCHAR || nt == SHORT || nt == USHORT)
return;
/* get default promotion */
ptn = promote(NOOP, 1, tn);
ot = ptn->tn_type->t_tspec;
/* return if types are the same with and without prototype */
if (nt == ot || (nt == ENUM && ot == INT))
return;
if (isftyp(nt) != isftyp(ot) || psize(nt) != psize(ot)) {
/* representation and/or width change */
if (styp(nt) != SHORT || !isityp(ot) || psize(ot) > psize(INT))
/* conversion to '%s' due to prototype, arg #%d */
warning(259, tyname(tp), arg);
} else if (hflag) {
/*
* they differ in sign or base type (char, short, int,
* long, long long, float, double, long double)
*
* if they differ only in sign and the argument is a constant
* and the msb of the argument is not set, print no warning
*/
if (ptn->tn_op == CON && isityp(nt) && styp(nt) == styp(ot) &&
msb(ptn->tn_val->v_quad, ot, -1) == 0) {
/* ok */
} else {
/* conversion to '%s' due to prototype, arg #%d */
warning(259, tyname(tp), arg);
}
}
}
/*
* Print warnings for conversions of integer types which my cause
* problems.
*/
/* ARGSUSED */
static void
iiconv(op_t op, int arg, tspec_t nt, tspec_t ot, type_t *tp, tnode_t *tn)
{
if (tn->tn_op == CON)
return;
if (op == CVT)
return;
#if 0
if (psize(nt) > psize(ot) && isutyp(nt) != isutyp(ot)) {
/* conversion to %s may sign-extend incorrectly (, arg #%d) */
if (aflag && pflag) {
if (op == FARG) {
warning(297, tyname(tp), arg);
} else {
warning(131, tyname(tp));
}
}
}
#endif
if (psize(nt) < psize(ot) &&
(ot == LONG || ot == ULONG || ot == QUAD || ot == UQUAD ||
aflag > 1)) {
/* conversion from '%s' may lose accuracy */
if (aflag) {
if (op == FARG) {
warning(298, tyname(tn->tn_type), arg);
} else {
warning(132, tyname(tn->tn_type));
}
}
}
}
/*
* Print warnings for dubious conversions of pointer to integer.
*/
static void
piconv(op_t op, tspec_t nt, type_t *tp, tnode_t *tn)
{
if (tn->tn_op == CON)
return;
if (op != CVT) {
/* We got already an error. */
return;
}
if (psize(nt) < psize(PTR)) {
if (pflag && size(nt) >= size(PTR)) {
/* conv. of pointer to %s may lose bits */
warning(134, tyname(tp));
} else {
/* conv. of pointer to %s loses bits */
warning(133, tyname(tp));
}
}
}
/*
* Print warnings for questionable pointer conversions.
*/
static void
ppconv(op_t op, tnode_t *tn, type_t *tp)
{
tspec_t nt, ot;
const char *nts, *ots;
/*
* We got already an error (pointers of different types
* without a cast) or we will not get a warning.
*/
if (op != CVT)
return;
nt = tp->t_subt->t_tspec;
ot = tn->tn_type->t_subt->t_tspec;
if (nt == VOID || ot == VOID) {
if (sflag && (nt == FUNC || ot == FUNC)) {
/* (void *)0 already handled in convert() */
*(nt == FUNC ? &nts : &ots) = "function pointer";
*(nt == VOID ? &nts : &ots) = "'void *'";
/* ANSI C forbids conversion of %s to %s */
warning(303, ots, nts);
}
return;
} else if (nt == FUNC && ot == FUNC) {
return;
} else if (nt == FUNC || ot == FUNC) {
/* questionable conversion of function pointer */
warning(229);
return;
}
if (getbound(tp->t_subt) > getbound(tn->tn_type->t_subt)) {
if (hflag)
/* possible pointer alignment problem */
warning(135);
}
if (((nt == STRUCT || nt == UNION) &&
tp->t_subt->t_str != tn->tn_type->t_subt->t_str) ||
psize(nt) != psize(ot)) {
if (cflag) {
/* pointer casts may be troublesome */
warning(247);
}
}
}
/*
* Converts a typed constant in a constant of another type.
*
* op operator which requires conversion
* arg if op is FARG, # of argument
* tp type in which to convert the constant
* nv new constant
* v old constant
*/
void
cvtcon(op_t op, int arg, type_t *tp, val_t *nv, val_t *v)
{
tspec_t ot, nt;
ldbl_t max = 0.0, min = 0.0;
int sz, rchk;
int64_t xmask, xmsk1;
int osz, nsz;
ot = v->v_tspec;
nt = nv->v_tspec = tp->t_tspec;
rchk = 0;
if (ot == FLOAT || ot == DOUBLE || ot == LDOUBLE) {
switch (nt) {
case CHAR:
max = CHAR_MAX; min = CHAR_MIN; break;
case UCHAR:
max = UCHAR_MAX; min = 0; break;
case SCHAR:
max = SCHAR_MAX; min = SCHAR_MIN; break;
case SHORT:
max = SHRT_MAX; min = SHRT_MIN; break;
case USHORT:
max = USHRT_MAX; min = 0; break;
case ENUM:
case INT:
max = INT_MAX; min = INT_MIN; break;
case UINT:
max = (u_int)UINT_MAX; min = 0; break;
case LONG:
max = LONG_MAX; min = LONG_MIN; break;
case ULONG:
max = (u_long)ULONG_MAX; min = 0; break;
case QUAD:
max = QUAD_MAX; min = QUAD_MIN; break;
case UQUAD:
max = (uint64_t)UQUAD_MAX; min = 0; break;
case FLOAT:
max = FLT_MAX; min = -FLT_MAX; break;
case DOUBLE:
max = DBL_MAX; min = -DBL_MAX; break;
case PTR:
/* Got already an error because of float --> ptr */
case LDOUBLE:
max = LDBL_MAX; min = -LDBL_MAX; break;
default:
lerror("cvtcon() 1");
}
if (v->v_ldbl > max || v->v_ldbl < min) {
if (nt == LDOUBLE)
lerror("cvtcon() 2");
if (op == FARG) {
/* conv. of %s to %s is out of rng., arg #%d */
warning(295, tyname(gettyp(ot)), tyname(tp),
arg);
} else {
/* conversion of %s to %s is out of range */
warning(119, tyname(gettyp(ot)), tyname(tp));
}
v->v_ldbl = v->v_ldbl > 0 ? max : min;
}
if (nt == FLOAT) {
nv->v_ldbl = (float)v->v_ldbl;
} else if (nt == DOUBLE) {
nv->v_ldbl = (double)v->v_ldbl;
} else if (nt == LDOUBLE) {
nv->v_ldbl = v->v_ldbl;
} else {
nv->v_quad = (nt == PTR || isutyp(nt)) ?
(uint64_t)v->v_ldbl : (int64_t)v->v_ldbl;
}
} else {
if (nt == FLOAT) {
nv->v_ldbl = (ot == PTR || isutyp(ot)) ?
(float)(uint64_t)v->v_quad : (float)v->v_quad;
} else if (nt == DOUBLE) {
nv->v_ldbl = (ot == PTR || isutyp(ot)) ?
(double)(uint64_t)v->v_quad : (double)v->v_quad;
} else if (nt == LDOUBLE) {
nv->v_ldbl = (ot == PTR || isutyp(ot)) ?
(ldbl_t)(uint64_t)v->v_quad : (ldbl_t)v->v_quad;
} else {
rchk = 1; /* Check for lost precision. */
nv->v_quad = v->v_quad;
}
}
if (v->v_ansiu && isftyp(nt)) {
/* ANSI C treats constant as unsigned */
warning(157);
v->v_ansiu = 0;
} else if (v->v_ansiu && (isityp(nt) && !isutyp(nt) &&
psize(nt) > psize(ot))) {
/* ANSI C treats constant as unsigned */
warning(157);
v->v_ansiu = 0;
}
if (nt != FLOAT && nt != DOUBLE && nt != LDOUBLE) {
sz = tp->t_isfield ? tp->t_flen : size(nt);
nv->v_quad = xsign(nv->v_quad, nt, sz);
}
if (rchk && op != CVT) {
osz = size(ot);
nsz = tp->t_isfield ? tp->t_flen : size(nt);
xmask = qlmasks[nsz] ^ qlmasks[osz];
xmsk1 = qlmasks[nsz] ^ qlmasks[osz - 1];
/*
* For bitwise operations we are not interested in the
* value, but in the bits itself.
*/
if (op == ORASS || op == OR || op == XOR) {
/*
* Print a warning if bits which were set are
* lost due to the conversion.
* This can happen with operator ORASS only.
*/
if (nsz < osz && (v->v_quad & xmask) != 0) {
/* constant truncated by conv., op %s */
warning(306, modtab[op].m_name);
}
} else if (op == ANDASS || op == AND) {
/*
* Print a warning if additional bits are not all 1
* and the most significant bit of the old value is 1,
* or if at least one (but not all) removed bit was 0.
*/
if (nsz > osz &&
(nv->v_quad & qbmasks[osz - 1]) != 0 &&
(nv->v_quad & xmask) != xmask) {
/*
* extra bits set to 0 in conversion
* of '%s' to '%s', op %s
*/
warning(309, tyname(gettyp(ot)),
tyname(tp), modtab[op].m_name);
} else if (nsz < osz &&
(v->v_quad & xmask) != xmask &&
(v->v_quad & xmask) != 0) {
/* const. truncated by conv., op %s */
warning(306, modtab[op].m_name);
}
} else if ((nt != PTR && isutyp(nt)) &&
(ot != PTR && !isutyp(ot)) && v->v_quad < 0) {
if (op == ASSIGN) {
/* assignment of negative constant to ... */
warning(164);
} else if (op == INIT) {
/* initialisation of unsigned with neg. ... */
warning(221);
} else if (op == FARG) {
/* conversion of neg. const. to ..., arg #%d */
warning(296, arg);
} else if (modtab[op].m_comp) {
/* we get this warning already in chkcomp() */
} else {
/* conversion of negative constant to ... */
warning(222);
}
} else if (nv->v_quad != v->v_quad && nsz <= osz &&
(v->v_quad & xmask) != 0 &&
(isutyp(ot) || (v->v_quad & xmsk1) != xmsk1)) {
/*
* Loss of significant bit(s). All truncated bits
* of unsigned types or all truncated bits plus the
* msb of the target for signed types are considered
* to be significant bits. Loss of significant bits
* means that at least on of the bits was set in an
* unsigned type or that at least one, but not all of
* the bits was set in an signed type.
* Loss of significant bits means that it is not
* possible, also not with necessary casts, to convert
* back to the original type. A example for a
* necessary cast is:
* char c; int i; c = 128;
* i = c; ** yields -128 **
* i = (unsigned char)c; ** yields 128 **
*/
if (op == ASSIGN && tp->t_isfield) {
/* precision lost in bit-field assignment */
warning(166);
} else if (op == ASSIGN) {
/* constant truncated by assignment */
warning(165);
} else if (op == INIT && tp->t_isfield) {
/* bit-field initializer does not fit */
warning(180);
} else if (op == INIT) {
/* initializer does not fit */
warning(178);
} else if (op == CASE) {
/* case label affected by conversion */
warning(196);
} else if (op == FARG) {
/* conv. of %s to %s is out of rng., arg #%d */
warning(295, tyname(gettyp(ot)), tyname(tp),
arg);
} else {
/* conversion of %s to %s is out of range */
warning(119, tyname(gettyp(ot)), tyname(tp));
}
} else if (nv->v_quad != v->v_quad) {
if (op == ASSIGN && tp->t_isfield) {
/* precision lost in bit-field assignment */
warning(166);
} else if (op == INIT && tp->t_isfield) {
/* bit-field initializer out of range */
warning(11);
} else if (op == CASE) {
/* case label affected by conversion */
warning(196);
} else if (op == FARG) {
/* conv. of %s to %s is out of rng., arg #%d */
warning(295, tyname(gettyp(ot)), tyname(tp),
arg);
} else {
/* conversion of %s to %s is out of range */
warning(119, tyname(gettyp(ot)), tyname(tp));
}
}
}
}
/*
* Called if incompatible types were detected.
* Prints a appropriate warning.
*/
static void
incompat(op_t op, tspec_t lt, tspec_t rt)
{
mod_t *mp;
mp = &modtab[op];
if (lt == VOID || (mp->m_binary && rt == VOID)) {
/* void type illegal in expression */
error(109);
} else if (op == ASSIGN) {
if ((lt == STRUCT || lt == UNION) &&
(rt == STRUCT || rt == UNION)) {
/* assignment of different structures */
error(240);
} else {
/* assignment type mismatch */
error(171);
}
} else if (mp->m_binary) {
/* operands of %s have incompatible types */
error(107, mp->m_name);
} else {
/* operand of %s has incompatible type */
error(108, mp->m_name);
}
}
/*
* Called if incompatible pointer types are detected.
* Print an appropriate warning.
*/
static void
illptrc(mod_t *mp, type_t *ltp, type_t *rtp)
{
tspec_t lt, rt;
if (ltp->t_tspec != PTR || rtp->t_tspec != PTR)
lerror("illptrc() 1");
lt = ltp->t_subt->t_tspec;
rt = rtp->t_subt->t_tspec;
if ((lt == STRUCT || lt == UNION) && (rt == STRUCT || rt == UNION)) {
if (mp == NULL) {
/* illegal structure pointer combination */
warning(244);
} else {
/* illegal structure pointer combination, op %s */
warning(245, mp->m_name);
}
} else {
if (mp == NULL) {
/* illegal pointer combination */
warning(184);
} else {
/* illegal pointer combination, op %s */
warning(124, mp->m_name);
}
}
}
/*
* Make sure type (*tpp)->t_subt has at least the qualifiers
* of tp1->t_subt and tp2->t_subt.
*/
static void
mrgqual(type_t **tpp, type_t *tp1, type_t *tp2)
{
if ((*tpp)->t_tspec != PTR ||
tp1->t_tspec != PTR || tp2->t_tspec != PTR) {
lerror("mrgqual()");
}
if ((*tpp)->t_subt->t_const ==
(tp1->t_subt->t_const | tp2->t_subt->t_const) &&
(*tpp)->t_subt->t_volatile ==
(tp1->t_subt->t_volatile | tp2->t_subt->t_volatile)) {
return;
}
*tpp = tduptyp(*tpp);
(*tpp)->t_subt = tduptyp((*tpp)->t_subt);
(*tpp)->t_subt->t_const =
tp1->t_subt->t_const | tp2->t_subt->t_const;
(*tpp)->t_subt->t_volatile =
tp1->t_subt->t_volatile | tp2->t_subt->t_volatile;
}
/*
* Returns 1 if the given structure or union has a constant member
* (maybe recursively).
*/
static int
conmemb(type_t *tp)
{
sym_t *m;
tspec_t t;
if ((t = tp->t_tspec) != STRUCT && t != UNION)
lerror("conmemb()");
for (m = tp->t_str->memb; m != NULL; m = m->s_nxt) {
tp = m->s_type;
if (tp->t_const)
return (1);
if ((t = tp->t_tspec) == STRUCT || t == UNION) {
if (conmemb(m->s_type))
return (1);
}
}
return (0);
}
const char *
tyname(type_t *tp)
{
tspec_t t;
const char *s;
if ((t = tp->t_tspec) == INT && tp->t_isenum)
t = ENUM;
switch (t) {
case CHAR: s = "char"; break;
case UCHAR: s = "unsigned char"; break;
case SCHAR: s = "signed char"; break;
case SHORT: s = "short"; break;
case USHORT: s = "unsigned short"; break;
case INT: s = "int"; break;
case UINT: s = "unsigned int"; break;
case LONG: s = "long"; break;
case ULONG: s = "unsigned long"; break;
case QUAD: s = "long long"; break;
case UQUAD: s = "unsigned long long"; break;
case FLOAT: s = "float"; break;
case DOUBLE: s = "double"; break;
case LDOUBLE: s = "long double"; break;
case PTR: s = "pointer"; break;
case ENUM: s = "enum"; break;
case STRUCT: s = "struct"; break;
case UNION: s = "union"; break;
case FUNC: s = "function"; break;
case ARRAY: s = "array"; break;
default:
lerror("tyname()");
}
return (s);
}
/*
* Create a new node for one of the operators POINT and ARROW.
*/
static tnode_t *
bldstr(op_t op, tnode_t *ln, tnode_t *rn)
{
tnode_t *ntn, *ctn;
int nolval;
if (rn->tn_op != NAME)
lerror("bldstr() 1");
if (rn->tn_sym->s_value.v_tspec != INT)
lerror("bldstr() 2");
if (rn->tn_sym->s_scl != MOS && rn->tn_sym->s_scl != MOU)
lerror("bldstr() 3");
/*
* Remember if the left operand is an lvalue (structure members
* are lvalues if and only if the structure itself is an lvalue).
*/
nolval = op == POINT && !ln->tn_lvalue;
if (op == POINT) {
ln = bldamper(ln, 1);
} else if (ln->tn_type->t_tspec != PTR) {
if (!tflag || !isityp(ln->tn_type->t_tspec))
lerror("bldstr() 4");
ln = convert(NOOP, 0, tincref(gettyp(VOID), PTR), ln);
}
#if PTRDIFF_IS_LONG
ctn = getinode(LONG, rn->tn_sym->s_value.v_quad / CHAR_BIT);
#else
ctn = getinode(INT, rn->tn_sym->s_value.v_quad / CHAR_BIT);
#endif
ntn = mktnode(PLUS, tincref(rn->tn_type, PTR), ln, ctn);
if (ln->tn_op == CON)
ntn = fold(ntn);
if (rn->tn_type->t_isfield) {
ntn = mktnode(FSEL, ntn->tn_type->t_subt, ntn, NULL);
} else {
ntn = mktnode(STAR, ntn->tn_type->t_subt, ntn, NULL);
}
if (nolval)
ntn->tn_lvalue = 0;
return (ntn);
}
/*
* Create a node for INCAFT, INCBEF, DECAFT and DECBEF.
*/
static tnode_t *
bldincdec(op_t op, tnode_t *ln)
{
tnode_t *cn, *ntn;
if (ln == NULL)
lerror("bldincdec() 1");
if (ln->tn_type->t_tspec == PTR) {
cn = plength(ln->tn_type);
} else {
cn = getinode(INT, (int64_t)1);
}
ntn = mktnode(op, ln->tn_type, ln, cn);
return (ntn);
}
/*
* Create a tree node for the & operator
*/
static tnode_t *
bldamper(tnode_t *tn, int noign)
{
tnode_t *ntn;
tspec_t t;
if (!noign && ((t = tn->tn_type->t_tspec) == ARRAY || t == FUNC)) {
/* & before array or function: ignored */
if (tflag)
warning(127);
return (tn);
}
/* eliminate &* */
if (tn->tn_op == STAR &&
tn->tn_left->tn_type->t_tspec == PTR &&
tn->tn_left->tn_type->t_subt == tn->tn_type) {
return (tn->tn_left);
}
ntn = mktnode(AMPER, tincref(tn->tn_type, PTR), tn, NULL);
return (ntn);
}
/*
* Create a node for operators PLUS and MINUS.
*/
static tnode_t *
bldplmi(op_t op, tnode_t *ln, tnode_t *rn)
{
tnode_t *ntn, *ctn;
type_t *tp;
/* If pointer and integer, then pointer to the lhs. */
if (rn->tn_type->t_tspec == PTR && isityp(ln->tn_type->t_tspec)) {
ntn = ln;
ln = rn;
rn = ntn;
}
if (ln->tn_type->t_tspec == PTR && rn->tn_type->t_tspec != PTR) {
if (!isityp(rn->tn_type->t_tspec))
lerror("bldplmi() 1");
ctn = plength(ln->tn_type);
if (rn->tn_type->t_tspec != ctn->tn_type->t_tspec)
rn = convert(NOOP, 0, ctn->tn_type, rn);
rn = mktnode(MULT, rn->tn_type, rn, ctn);
if (rn->tn_left->tn_op == CON)
rn = fold(rn);
ntn = mktnode(op, ln->tn_type, ln, rn);
} else if (rn->tn_type->t_tspec == PTR) {
if (ln->tn_type->t_tspec != PTR || op != MINUS)
lerror("bldplmi() 2");
#if PTRDIFF_IS_LONG
tp = gettyp(LONG);
#else
tp = gettyp(INT);
#endif
ntn = mktnode(op, tp, ln, rn);
if (ln->tn_op == CON && rn->tn_op == CON)
ntn = fold(ntn);
ctn = plength(ln->tn_type);
balance(NOOP, &ntn, &ctn);
ntn = mktnode(DIV, tp, ntn, ctn);
} else {
ntn = mktnode(op, ln->tn_type, ln, rn);
}
return (ntn);
}
/*
* Create a node for operators SHL and SHR.
*/
static tnode_t *
bldshft(op_t op, tnode_t *ln, tnode_t *rn)
{
tspec_t t;
tnode_t *ntn;
if ((t = rn->tn_type->t_tspec) != INT && t != UINT)
rn = convert(CVT, 0, gettyp(INT), rn);
ntn = mktnode(op, ln->tn_type, ln, rn);
return (ntn);
}
/*
* Create a node for COLON.
*/
static tnode_t *
bldcol(tnode_t *ln, tnode_t *rn)
{
tspec_t lt, rt, pdt;
type_t *rtp;
tnode_t *ntn;
lt = ln->tn_type->t_tspec;
rt = rn->tn_type->t_tspec;
#if PTRDIFF_IS_LONG
pdt = LONG;
#else
pdt = INT;
#endif
/*
* Arithmetic types are balanced, all other type combinations
* still need to be handled.
*/
if (isatyp(lt) && isatyp(rt)) {
rtp = ln->tn_type;
} else if (lt == VOID || rt == VOID) {
rtp = gettyp(VOID);
} else if (lt == STRUCT || lt == UNION) {
/* Both types must be identical. */
if (rt != STRUCT && rt != UNION)
lerror("bldcol() 1");
if (ln->tn_type->t_str != rn->tn_type->t_str)
lerror("bldcol() 2");
if (incompl(ln->tn_type)) {
/* unknown operand size, op %s */
error(138, modtab[COLON].m_name);
return (NULL);
}
rtp = ln->tn_type;
} else if (lt == PTR && isityp(rt)) {
if (rt != pdt) {
rn = convert(NOOP, 0, gettyp(pdt), rn);
rt = pdt;
}
rtp = ln->tn_type;
} else if (rt == PTR && isityp(lt)) {
if (lt != pdt) {
ln = convert(NOOP, 0, gettyp(pdt), ln);
lt = pdt;
}
rtp = rn->tn_type;
} else if (lt == PTR && ln->tn_type->t_subt->t_tspec == VOID) {
if (rt != PTR)
lerror("bldcol() 4");
rtp = ln->tn_type;
mrgqual(&rtp, ln->tn_type, rn->tn_type);
} else if (rt == PTR && rn->tn_type->t_subt->t_tspec == VOID) {
if (lt != PTR)
lerror("bldcol() 5");
rtp = rn->tn_type;
mrgqual(&rtp, ln->tn_type, rn->tn_type);
} else {
if (lt != PTR || rt != PTR)
lerror("bldcol() 6");
/*
* XXX For now we simply take the left type. This is
* probably wrong, if one type contains a functionprototype
* and the other one, at the same place, only an old style
* declaration.
*/
rtp = ln->tn_type;
mrgqual(&rtp, ln->tn_type, rn->tn_type);
}
ntn = mktnode(COLON, rtp, ln, rn);
return (ntn);
}
/*
* Create a node for an assignment operator (both = and op= ).
*/
static tnode_t *
bldasgn(op_t op, tnode_t *ln, tnode_t *rn)
{
tspec_t lt, rt;
tnode_t *ntn, *ctn;
if (ln == NULL || rn == NULL)
lerror("bldasgn() 1");
lt = ln->tn_type->t_tspec;
rt = rn->tn_type->t_tspec;
if ((op == ADDASS || op == SUBASS) && lt == PTR) {
if (!isityp(rt))
lerror("bldasgn() 2");
ctn = plength(ln->tn_type);
if (rn->tn_type->t_tspec != ctn->tn_type->t_tspec)
rn = convert(NOOP, 0, ctn->tn_type, rn);
rn = mktnode(MULT, rn->tn_type, rn, ctn);
if (rn->tn_left->tn_op == CON)
rn = fold(rn);
}
if ((op == ASSIGN || op == RETURN) && (lt == STRUCT || rt == STRUCT)) {
if (rt != lt || ln->tn_type->t_str != rn->tn_type->t_str)
lerror("bldasgn() 3");
if (incompl(ln->tn_type)) {
if (op == RETURN) {
/* cannot return incomplete type */
error(212);
} else {
/* unknown operand size, op %s */
error(138, modtab[op].m_name);
}
return (NULL);
}
}
if (op == SHLASS || op == SHRASS) {
if (rt != INT) {
rn = convert(NOOP, 0, gettyp(INT), rn);
rt = INT;
}
} else {
if (op == ASSIGN || lt != PTR) {
if (lt != rt ||
(ln->tn_type->t_isfield && rn->tn_op == CON)) {
rn = convert(op, 0, ln->tn_type, rn);
rt = lt;
}
}
}
ntn = mktnode(op, ln->tn_type, ln, rn);
return (ntn);
}
/*
* Get length of type tp->t_subt.
*/
static tnode_t *
plength(type_t *tp)
{
int elem, elsz;
tspec_t st;
if (tp->t_tspec != PTR)
lerror("plength() 1");
tp = tp->t_subt;
elem = 1;
elsz = 0;
while (tp->t_tspec == ARRAY) {
elem *= tp->t_dim;
tp = tp->t_subt;
}
switch (tp->t_tspec) {
case FUNC:
/* pointer to function is not allowed here */
error(110);
break;
case VOID:
/* cannot do pointer arithmetic on operand of ... */
(void)gnuism(136);
break;
case STRUCT:
case UNION:
if ((elsz = tp->t_str->size) == 0)
/* cannot do pointer arithmetic on operand of ... */
error(136);
break;
case ENUM:
if (incompl(tp)) {
/* cannot do pointer arithmetic on operand of ... */
warning(136);
}
/* FALLTHROUGH */
default:
if ((elsz = size(tp->t_tspec)) == 0) {
/* cannot do pointer arithmetic on operand of ... */
error(136);
} else if (elsz == -1) {
lerror("plength() 2");
}
break;
}
if (elem == 0 && elsz != 0) {
/* cannot do pointer arithmetic on operand of ... */
error(136);
}
if (elsz == 0)
elsz = CHAR_BIT;
#if PTRDIFF_IS_LONG
st = LONG;
#else
st = INT;
#endif
return (getinode(st, (int64_t)(elem * elsz / CHAR_BIT)));
}
/*
* XXX
* Note: There appear to be a number of bugs in detecting overflow in
* this function. An audit and a set of proper regression tests are needed.
* --Perry Metzger, Nov. 16, 2001
*/
/*
* Do only as much as necessary to compute constant expressions.
* Called only if the operator allows folding and (both) operands
* are constants.
*/
static tnode_t *
fold(tnode_t *tn)
{
val_t *v;
tspec_t t;
int utyp, ovfl;
int64_t sl, sr = 0, q = 0, mask;
uint64_t ul, ur = 0;
tnode_t *cn;
if ((v = calloc(1, sizeof (val_t))) == NULL)
nomem();
v->v_tspec = t = tn->tn_type->t_tspec;
utyp = t == PTR || isutyp(t);
ul = sl = tn->tn_left->tn_val->v_quad;
if (modtab[tn->tn_op].m_binary)
ur = sr = tn->tn_right->tn_val->v_quad;
mask = qlmasks[size(t)];
ovfl = 0;
switch (tn->tn_op) {
case UPLUS:
q = sl;
break;
case UMINUS:
q = -sl;
if (msb(q, t, -1) == msb(sl, t, -1))
ovfl = 1;
break;
case COMPL:
q = ~sl;
break;
case MULT:
if (utyp) {
q = ul * ur;
if (q != (q & mask))
ovfl = 1;
else if ((ul != 0) && ((q / ul) != ur))
ovfl = 1;
} else {
q = sl * sr;
if (msb(q, t, -1) != (msb(sl, t, -1) ^ msb(sr, t, -1)))
ovfl = 1;
}
break;
case DIV:
if (sr == 0) {
/* division by 0 */
error(139);
q = utyp ? UQUAD_MAX : QUAD_MAX;
} else {
q = utyp ? ul / ur : sl / sr;
}
break;
case MOD:
if (sr == 0) {
/* modulus by 0 */
error(140);
q = 0;
} else {
q = utyp ? ul % ur : sl % sr;
}
break;
case PLUS:
q = utyp ? ul + ur : sl + sr;
if (msb(sl, t, -1) != 0 && msb(sr, t, -1) != 0) {
if (msb(q, t, -1) == 0)
ovfl = 1;
} else if (msb(sl, t, -1) == 0 && msb(sr, t, -1) == 0) {
if (msb(q, t, -1) != 0)
ovfl = 1;
}
break;
case MINUS:
q = utyp ? ul - ur : sl - sr;
if (msb(sl, t, -1) != 0 && msb(sr, t, -1) == 0) {
if (msb(q, t, -1) == 0)
ovfl = 1;
} else if (msb(sl, t, -1) == 0 && msb(sr, t, -1) != 0) {
if (msb(q, t, -1) != 0)
ovfl = 1;
}
break;
case SHL:
q = utyp ? ul << sr : sl << sr;
break;
case SHR:
/*
* The sign must be explicitly extended because
* shifts of signed values are implementation dependent.
*/
q = ul >> sr;
q = xsign(q, t, size(t) - (int)sr);
break;
case LT:
q = utyp ? ul < ur : sl < sr;
break;
case LE:
q = utyp ? ul <= ur : sl <= sr;
break;
case GE:
q = utyp ? ul >= ur : sl >= sr;
break;
case GT:
q = utyp ? ul > ur : sl > sr;
break;
case EQ:
q = utyp ? ul == ur : sl == sr;
break;
case NE:
q = utyp ? ul != ur : sl != sr;
break;
case AND:
q = utyp ? ul & ur : sl & sr;
break;
case XOR:
q = utyp ? ul ^ ur : sl ^ sr;
break;
case OR:
q = utyp ? ul | ur : sl | sr;
break;
default:
lerror("fold() 5");
}
/* XXX does not work for quads. */
if (ovfl || ((q | mask) != ~(uint64_t)0 && (q & ~mask) != 0)) {
if (hflag)
/* integer overflow detected, op %s */
warning(141, modtab[tn->tn_op].m_name);
}
v->v_quad = xsign(q, t, -1);
cn = getcnode(tn->tn_type, v);
return (cn);
}
/*
* Same for operators whose operands are compared with 0 (test context).
*/
static tnode_t *
foldtst(tnode_t *tn)
{
int l, r = 0;
val_t *v;
if ((v = calloc(1, sizeof (val_t))) == NULL)
nomem();
v->v_tspec = tn->tn_type->t_tspec;
if (tn->tn_type->t_tspec != INT)
lerror("foldtst() 1");
if (isftyp(tn->tn_left->tn_type->t_tspec)) {
l = tn->tn_left->tn_val->v_ldbl != 0.0;
} else {
l = tn->tn_left->tn_val->v_quad != 0;
}
if (modtab[tn->tn_op].m_binary) {
if (isftyp(tn->tn_right->tn_type->t_tspec)) {
r = tn->tn_right->tn_val->v_ldbl != 0.0;
} else {
r = tn->tn_right->tn_val->v_quad != 0;
}
}
switch (tn->tn_op) {
case NOT:
if (hflag)
/* constant argument to NOT */
warning(239);
v->v_quad = !l;
break;
case LOGAND:
v->v_quad = l && r;
break;
case LOGOR:
v->v_quad = l || r;
break;
default:
lerror("foldtst() 1");
}
return (getcnode(tn->tn_type, v));
}
/*
* Same for operands with floating point type.
*/
static tnode_t *
foldflt(tnode_t *tn)
{
val_t *v;
tspec_t t;
ldbl_t l, r = 0;
if ((v = calloc(1, sizeof (val_t))) == NULL)
nomem();
v->v_tspec = t = tn->tn_type->t_tspec;
if (!isftyp(t))
lerror("foldflt() 1");
if (t != tn->tn_left->tn_type->t_tspec)
lerror("foldflt() 2");
if (modtab[tn->tn_op].m_binary && t != tn->tn_right->tn_type->t_tspec)
lerror("foldflt() 3");
l = tn->tn_left->tn_val->v_ldbl;
if (modtab[tn->tn_op].m_binary)
r = tn->tn_right->tn_val->v_ldbl;
switch (tn->tn_op) {
case UPLUS:
v->v_ldbl = l;
break;
case UMINUS:
v->v_ldbl = -l;
break;
case MULT:
v->v_ldbl = l * r;
break;
case DIV:
if (r == 0.0) {
/* division by 0 */
error(139);
if (t == FLOAT) {
v->v_ldbl = l < 0 ? -FLT_MAX : FLT_MAX;
} else if (t == DOUBLE) {
v->v_ldbl = l < 0 ? -DBL_MAX : DBL_MAX;
} else {
v->v_ldbl = l < 0 ? -LDBL_MAX : LDBL_MAX;
}
} else {
v->v_ldbl = l / r;
}
break;
case PLUS:
v->v_ldbl = l + r;
break;
case MINUS:
v->v_ldbl = l - r;
break;
case LT:
v->v_quad = l < r;
break;
case LE:
v->v_quad = l <= r;
break;
case GE:
v->v_quad = l >= r;
break;
case GT:
v->v_quad = l > r;
break;
case EQ:
v->v_quad = l == r;
break;
case NE:
v->v_quad = l != r;
break;
default:
lerror("foldflt() 4");
}
if (isnan((double)v->v_ldbl))
lerror("foldflt() 5");
if (!finite((double)v->v_ldbl) ||
(t == FLOAT &&
(v->v_ldbl > FLT_MAX || v->v_ldbl < -FLT_MAX)) ||
(t == DOUBLE &&
(v->v_ldbl > DBL_MAX || v->v_ldbl < -DBL_MAX))) {
/* floating point overflow detected, op %s */
warning(142, modtab[tn->tn_op].m_name);
if (t == FLOAT) {
v->v_ldbl = v->v_ldbl < 0 ? -FLT_MAX : FLT_MAX;
} else if (t == DOUBLE) {
v->v_ldbl = v->v_ldbl < 0 ? -DBL_MAX : DBL_MAX;
} else {
v->v_ldbl = v->v_ldbl < 0 ? -LDBL_MAX: LDBL_MAX;
}
}
return (getcnode(tn->tn_type, v));
}
/*
* Create a constant node for sizeof.
*/
tnode_t *
bldszof(type_t *tp)
{
int elem, elsz;
tspec_t st;
elem = 1;
while (tp->t_tspec == ARRAY) {
elem *= tp->t_dim;
tp = tp->t_subt;
}
if (elem == 0) {
/* cannot take size of incomplete type */
error(143);
elem = 1;
}
switch (tp->t_tspec) {
case FUNC:
/* cannot take size of function */
error(144);
elsz = 1;
break;
case STRUCT:
case UNION:
if (incompl(tp)) {
/* cannot take size of incomplete type */
error(143);
elsz = 1;
} else {
elsz = tp->t_str->size;
}
break;
case ENUM:
if (incompl(tp)) {
/* cannot take size of incomplete type */
warning(143);
}
/* FALLTHROUGH */
default:
if (tp->t_isfield) {
/* cannot take size of bit-field */
error(145);
}
if (tp->t_tspec == VOID) {
/* cannot take size of void */
error(146);
elsz = 1;
} else {
elsz = size(tp->t_tspec);
if (elsz <= 0)
lerror("bldszof() 1");
}
break;
}
#if SIZEOF_IS_ULONG
st = ULONG;
#else
st = UINT;
#endif
return (getinode(st, (int64_t)(elem * elsz / CHAR_BIT)));
}
/*
* Type casts.
*/
tnode_t *
cast(tnode_t *tn, type_t *tp)
{
tspec_t nt, ot;
if (tn == NULL)
return (NULL);
tn = cconv(tn);
nt = tp->t_tspec;
ot = tn->tn_type->t_tspec;
if (nt == VOID) {
/*
* XXX ANSI C requires scalar types or void (Plauger&Brodie).
* But this seams really questionable.
*/
} else if (nt == STRUCT || nt == UNION || nt == ARRAY || nt == FUNC) {
/* invalid cast expression */
error(147);
return (NULL);
} else if (ot == STRUCT || ot == UNION) {
/* invalid cast expression */
error(147);
return (NULL);
} else if (ot == VOID) {
/* improper cast of void expression */
error(148);
return (NULL);
} else if (isityp(nt) && issclt(ot)) {
/* ok */
} else if (isftyp(nt) && isatyp(ot)) {
/* ok */
} else if (nt == PTR && isityp(ot)) {
/* ok */
} else if (nt == PTR && ot == PTR) {
if (!tp->t_subt->t_const && tn->tn_type->t_subt->t_const) {
if (hflag)
/* cast discards 'const' from ... */
warning(275);
}
} else {
/* invalid cast expression */
error(147);
return (NULL);
}
tn = convert(CVT, 0, tp, tn);
tn->tn_cast = 1;
return (tn);
}
/*
* Create the node for a function argument.
* All necessary conversions and type checks are done in funccall(), because
* in funcarg() we have no information about expected argument types.
*/
tnode_t *
funcarg(tnode_t *args, tnode_t *arg)
{
tnode_t *ntn;
/*
* If there was a serious error in the expression for the argument,
* create a dummy argument so the positions of the remaining arguments
* will not change.
*/
if (arg == NULL)
arg = getinode(INT, (int64_t)0);
ntn = mktnode(PUSH, arg->tn_type, arg, args);
return (ntn);
}
/*
* Create the node for a function call. Also check types of
* function arguments and insert conversions, if necessary.
*/
tnode_t *
funccall(tnode_t *func, tnode_t *args)
{
tnode_t *ntn;
op_t fcop;
if (func == NULL)
return (NULL);
if (func->tn_op == NAME && func->tn_type->t_tspec == FUNC) {
fcop = CALL;
} else {
fcop = ICALL;
}
/*
* after cconv() func will always be a pointer to a function
* if it is a valid function designator.
*/
func = cconv(func);
if (func->tn_type->t_tspec != PTR ||
func->tn_type->t_subt->t_tspec != FUNC) {
/* illegal function */
error(149);
return (NULL);
}
args = chkfarg(func->tn_type->t_subt, args);
ntn = mktnode(fcop, func->tn_type->t_subt->t_subt, func, args);
return (ntn);
}
/*
* Check types of all function arguments and insert conversions,
* if necessary.
*/
static tnode_t *
chkfarg(type_t *ftp, tnode_t *args)
{
tnode_t *arg;
sym_t *asym;
tspec_t at;
int narg, npar, n, i;
/* get # of args in the prototype */
npar = 0;
for (asym = ftp->t_args; asym != NULL; asym = asym->s_nxt)
npar++;
/* get # of args in function call */
narg = 0;
for (arg = args; arg != NULL; arg = arg->tn_right)
narg++;
asym = ftp->t_args;
if (ftp->t_proto && npar != narg && !(ftp->t_vararg && npar < narg)) {
/* argument mismatch: %d arg%s passed, %d expected */
error(150, narg, narg > 1 ? "s" : "", npar);
asym = NULL;
}
for (n = 1; n <= narg; n++) {
/*
* The rightmost argument is at the top of the argument
* subtree.
*/
for (i = narg, arg = args; i > n; i--, arg = arg->tn_right)
continue;
/* some things which are always not allowd */
if ((at = arg->tn_left->tn_type->t_tspec) == VOID) {
/* void expressions may not be arguments, arg #%d */
error(151, n);
return (NULL);
} else if ((at == STRUCT || at == UNION) &&
incompl(arg->tn_left->tn_type)) {
/* argument cannot have unknown size, arg #%d */
error(152, n);
return (NULL);
} else if (isityp(at) && arg->tn_left->tn_type->t_isenum &&
incompl(arg->tn_left->tn_type)) {
/* argument cannot have unknown size, arg #%d */
warning(152, n);
}
/* class conversions (arg in value context) */
arg->tn_left = cconv(arg->tn_left);
if (asym != NULL) {
arg->tn_left = parg(n, asym->s_type, arg->tn_left);
} else {
arg->tn_left = promote(NOOP, 1, arg->tn_left);
}
arg->tn_type = arg->tn_left->tn_type;
if (asym != NULL)
asym = asym->s_nxt;
}
return (args);
}
/*
* Compare the type of an argument with the corresponding type of a
* prototype parameter. If it is a valid combination, but both types
* are not the same, insert a conversion to convert the argument into
* the type of the parameter.
*/
static tnode_t *
parg( int n, /* pos of arg */
type_t *tp, /* expected type (from prototype) */
tnode_t *tn) /* argument */
{
tnode_t *ln;
int warn;
if ((ln = calloc(1, sizeof (tnode_t))) == NULL)
nomem();
ln->tn_type = tduptyp(tp);
ln->tn_type->t_const = 0;
ln->tn_lvalue = 1;
if (typeok(FARG, n, ln, tn)) {
if (!eqtype(tp, tn->tn_type, 1, 0, (warn = 0, &warn)) || warn)
tn = convert(FARG, n, tp, tn);
}
free(ln);
return (tn);
}
/*
* Return the value of an integral constant expression.
* If the expression is not constant or its type is not an integer
* type, an error message is printed.
*/
val_t *
constant(tnode_t *tn)
{
val_t *v;
if (tn != NULL)
tn = cconv(tn);
if (tn != NULL)
tn = promote(NOOP, 0, tn);
if ((v = calloc(1, sizeof (val_t))) == NULL)
nomem();
if (tn == NULL) {
if (nerr == 0)
lerror("constant() 1");
v->v_tspec = INT;
v->v_quad = 1;
return (v);
}
v->v_tspec = tn->tn_type->t_tspec;
if (tn->tn_op == CON) {
if (tn->tn_type->t_tspec != tn->tn_val->v_tspec)
lerror("constant() 2");
if (isityp(tn->tn_val->v_tspec)) {
v->v_ansiu = tn->tn_val->v_ansiu;
v->v_quad = tn->tn_val->v_quad;
return (v);
}
v->v_quad = tn->tn_val->v_ldbl;
} else {
v->v_quad = 1;
}
/* integral constant expression expected */
error(55);
if (!isityp(v->v_tspec))
v->v_tspec = INT;
return (v);
}
/*
* Perform some tests on expressions which can't be done in build() and
* functions called by build(). These tests must be done here because
* we need some information about the context in which the operations
* are performed.
* After all tests are performed, expr() frees the memory which is used
* for the expression.
*/
void
expr(tnode_t *tn, int vctx, int tctx)
{
if (tn == NULL && nerr == 0)
lerror("expr() 1");
if (tn == NULL) {
tfreeblk();
return;
}
/* expr() is also called in global initialisations */
if (dcs->d_ctx != EXTERN)
chkreach();
chkmisc(tn, vctx, tctx, !tctx, 0, 0, 0);
if (tn->tn_op == ASSIGN) {
if (hflag && tctx)
/* assignment in conditional context */
warning(159);
} else if (tn->tn_op == CON) {
if (hflag && tctx && !ccflg)
/* constant in conditional context */
warning(161);
}
if (!modtab[tn->tn_op].m_sideeff) {
/*
* for left operands of COMMA this warning is already
* printed
*/
if (tn->tn_op != COMMA && !vctx && !tctx)
nulleff(tn);
}
if (dflag)
displexpr(tn, 0);
/* free the tree memory */
tfreeblk();
}
static void
nulleff(tnode_t *tn)
{
if (!hflag)
return;
while (!modtab[tn->tn_op].m_sideeff) {
if (tn->tn_op == CVT && tn->tn_type->t_tspec == VOID) {
tn = tn->tn_left;
} else if (tn->tn_op == LOGAND || tn->tn_op == LOGOR) {
/*
* && and || have a side effect if the right operand
* has a side effect.
*/
tn = tn->tn_right;
} else if (tn->tn_op == QUEST) {
/*
* ? has a side effect if at least one of its right
* operands has a side effect
*/
tn = tn->tn_right;
} else if (tn->tn_op == COLON || tn->tn_op == COMMA) {
/*
* : has a side effect if at least one of its operands
* has a side effect
*/
if (modtab[tn->tn_left->tn_op].m_sideeff) {
tn = tn->tn_left;
} else if (modtab[tn->tn_right->tn_op].m_sideeff) {
tn = tn->tn_right;
} else {
break;
}
} else {
break;
}
}
if (!modtab[tn->tn_op].m_sideeff)
/* expression has null effect */
warning(129);
}
/*
* Dump an expression to stdout
* only used for debugging
*/
static void
displexpr(tnode_t *tn, int offs)
{
uint64_t uq;
if (tn == NULL) {
(void)printf("%*s%s\n", offs, "", "NULL");
return;
}
(void)printf("%*sop %s ", offs, "", modtab[tn->tn_op].m_name);
if (tn->tn_op == NAME) {
(void)printf("%s: %s ",
tn->tn_sym->s_name, scltoa(tn->tn_sym->s_scl));
} else if (tn->tn_op == CON && isftyp(tn->tn_type->t_tspec)) {
(void)printf("%#g ", (double)tn->tn_val->v_ldbl);
} else if (tn->tn_op == CON && isityp(tn->tn_type->t_tspec)) {
uq = tn->tn_val->v_quad;
(void)printf("0x %08lx %08lx ", (long)(uq >> 32) & 0xffffffffl,
(long)uq & 0xffffffffl);
} else if (tn->tn_op == CON) {
if (tn->tn_type->t_tspec != PTR)
lerror("displexpr() 1");
(void)printf("0x%0*lx ", (int)(sizeof (void *) * CHAR_BIT / 4),
(u_long)tn->tn_val->v_quad);
} else if (tn->tn_op == STRING) {
if (tn->tn_strg->st_tspec == CHAR) {
(void)printf("\"%s\"", tn->tn_strg->st_cp);
} else {
char *s;
size_t n;
n = MB_CUR_MAX * (tn->tn_strg->st_len + 1);
if ((s = malloc(n)) == NULL)
nomem();
(void)wcstombs(s, tn->tn_strg->st_wcp, n);
(void)printf("L\"%s\"", s);
free(s);
}
(void)printf(" ");
} else if (tn->tn_op == FSEL) {
(void)printf("o=%d, l=%d ", tn->tn_type->t_foffs,
tn->tn_type->t_flen);
}
(void)printf("%s\n", ttos(tn->tn_type));
if (tn->tn_op == NAME || tn->tn_op == CON || tn->tn_op == STRING)
return;
displexpr(tn->tn_left, offs + 2);
if (modtab[tn->tn_op].m_binary ||
(tn->tn_op == PUSH && tn->tn_right != NULL)) {
displexpr(tn->tn_right, offs + 2);
}
}
/*
* Called by expr() to recursively perform some tests.
*/
/* ARGSUSED */
void
chkmisc(tnode_t *tn, int vctx, int tctx, int eqwarn, int fcall, int rvdisc,
int szof)
{
tnode_t *ln, *rn;
mod_t *mp;
int nrvdisc, cvctx, ctctx;
op_t op;
scl_t sc;
dinfo_t *di;
if (tn == NULL)
return;
ln = tn->tn_left;
rn = tn->tn_right;
mp = &modtab[op = tn->tn_op];
switch (op) {
case AMPER:
if (ln->tn_op == NAME && (reached || rchflg)) {
if (!szof)
setsflg(ln->tn_sym);
setuflg(ln->tn_sym, fcall, szof);
}
if (ln->tn_op == STAR && ln->tn_left->tn_op == PLUS)
/* check the range of array indices */
chkaidx(ln->tn_left, 1);
break;
case LOAD:
if (ln->tn_op == STAR && ln->tn_left->tn_op == PLUS)
/* check the range of array indices */
chkaidx(ln->tn_left, 0);
/* FALLTHROUGH */
case PUSH:
case INCBEF:
case DECBEF:
case INCAFT:
case DECAFT:
case ADDASS:
case SUBASS:
case MULASS:
case DIVASS:
case MODASS:
case ANDASS:
case ORASS:
case XORASS:
case SHLASS:
case SHRASS:
if (ln->tn_op == NAME && (reached || rchflg)) {
sc = ln->tn_sym->s_scl;
/*
* Look if there was a asm statement in one of the
* compound statements we are in. If not, we don't
* print a warning.
*/
for (di = dcs; di != NULL; di = di->d_nxt) {
if (di->d_asm)
break;
}
if (sc != EXTERN && sc != STATIC &&
!ln->tn_sym->s_set && !szof && di == NULL) {
/* %s may be used before set */
warning(158, ln->tn_sym->s_name);
setsflg(ln->tn_sym);
}
setuflg(ln->tn_sym, 0, 0);
}
break;
case ASSIGN:
if (ln->tn_op == NAME && !szof && (reached || rchflg)) {
setsflg(ln->tn_sym);
if (ln->tn_sym->s_scl == EXTERN)
outusg(ln->tn_sym);
}
if (ln->tn_op == STAR && ln->tn_left->tn_op == PLUS)
/* check the range of array indices */
chkaidx(ln->tn_left, 0);
break;
case CALL:
if (ln->tn_op != AMPER || ln->tn_left->tn_op != NAME)
lerror("chkmisc() 1");
if (!szof)
outcall(tn, vctx || tctx, rvdisc);
break;
case EQ:
/* equality operator "==" found where "=" was exp. */
if (hflag && eqwarn)
warning(160);
break;
case CON:
case NAME:
case STRING:
return;
/* LINTED (enumeration values not handled in switch) */
case OR:
case XOR:
case NE:
case GE:
case GT:
case LE:
case LT:
case SHR:
case SHL:
case MINUS:
case PLUS:
case MOD:
case DIV:
case MULT:
case STAR:
case UMINUS:
case UPLUS:
case DEC:
case INC:
case COMPL:
case NOT:
case POINT:
case ARROW:
case NOOP:
case AND:
case FARG:
case CASE:
case INIT:
case RETURN:
case ICALL:
case CVT:
case COMMA:
case FSEL:
case COLON:
case QUEST:
case LOGOR:
case LOGAND:
break;
}
cvctx = mp->m_vctx;
ctctx = mp->m_tctx;
/*
* values of operands of ':' are not used if the type of at least
* one of the operands (for gcc compatibility) is void
* XXX test/value context of QUEST should probably be used as
* context for both operands of COLON
*/
if (op == COLON && tn->tn_type->t_tspec == VOID)
cvctx = ctctx = 0;
nrvdisc = op == CVT && tn->tn_type->t_tspec == VOID;
chkmisc(ln, cvctx, ctctx, mp->m_eqwarn, op == CALL, nrvdisc, szof);
switch (op) {
case PUSH:
if (rn != NULL)
chkmisc(rn, 0, 0, mp->m_eqwarn, 0, 0, szof);
break;
case LOGAND:
case LOGOR:
chkmisc(rn, 0, 1, mp->m_eqwarn, 0, 0, szof);
break;
case COLON:
chkmisc(rn, cvctx, ctctx, mp->m_eqwarn, 0, 0, szof);
break;
case COMMA:
chkmisc(rn, vctx, tctx, mp->m_eqwarn, 0, 0, szof);
break;
default:
if (mp->m_binary)
chkmisc(rn, 1, 0, mp->m_eqwarn, 0, 0, szof);
break;
}
}
/*
* Checks the range of array indices, if possible.
* amper is set if only the address of the element is used. This
* means that the index is allowd to refere to the first element
* after the array.
*/
static void
chkaidx(tnode_t *tn, int amper)
{
int dim;
tnode_t *ln, *rn;
int elsz;
int64_t con;
ln = tn->tn_left;
rn = tn->tn_right;
/* We can only check constant indices. */
if (rn->tn_op != CON)
return;
/* Return if the left node does not stem from an array. */
if (ln->tn_op != AMPER)
return;
if (ln->tn_left->tn_op != STRING && ln->tn_left->tn_op != NAME)
return;
if (ln->tn_left->tn_type->t_tspec != ARRAY)
return;
/*
* For incomplete array types, we can print a warning only if
* the index is negative.
*/
if (incompl(ln->tn_left->tn_type) && rn->tn_val->v_quad >= 0)
return;
/* Get the size of one array element */
if ((elsz = length(ln->tn_type->t_subt, NULL)) == 0)
return;
elsz /= CHAR_BIT;
/* Change the unit of the index from bytes to element size. */
if (isutyp(rn->tn_type->t_tspec)) {
con = (uint64_t)rn->tn_val->v_quad / elsz;
} else {
con = rn->tn_val->v_quad / elsz;
}
dim = ln->tn_left->tn_type->t_dim + (amper ? 1 : 0);
if (!isutyp(rn->tn_type->t_tspec) && con < 0) {
/* array subscript cannot be negative: %ld */
warning(167, (long)con);
} else if (dim > 0 && (uint64_t)con >= dim) {
/* array subscript cannot be > %d: %ld */
warning(168, dim - 1, (long)con);
}
}
/*
* Check for ordered comparisons of unsigned values with 0.
*/
static void
chkcomp(op_t op, tnode_t *ln, tnode_t *rn)
{
tspec_t lt, rt;
mod_t *mp;
lt = ln->tn_type->t_tspec;
rt = rn->tn_type->t_tspec;
mp = &modtab[op];
if (ln->tn_op != CON && rn->tn_op != CON)
return;
if (!isityp(lt) || !isityp(rt))
return;
if ((hflag || pflag) && lt == CHAR && rn->tn_op == CON &&
(rn->tn_val->v_quad < 0 ||
rn->tn_val->v_quad > ~(~0 << (CHAR_BIT - 1)))) {
/* nonportable character comparison, op %s */
warning(230, mp->m_name);
return;
}
if ((hflag || pflag) && rt == CHAR && ln->tn_op == CON &&
(ln->tn_val->v_quad < 0 ||
ln->tn_val->v_quad > ~(~0 << (CHAR_BIT - 1)))) {
/* nonportable character comparison, op %s */
warning(230, mp->m_name);
return;
}
if (isutyp(lt) && !isutyp(rt) &&
rn->tn_op == CON && rn->tn_val->v_quad <= 0) {
if (rn->tn_val->v_quad < 0) {
/* comparison of %s with %s, op %s */
warning(162, tyname(ln->tn_type), "negative constant",
mp->m_name);
} else if (op == LT || op == GE || (hflag && op == LE)) {
/* comparison of %s with %s, op %s */
warning(162, tyname(ln->tn_type), "0", mp->m_name);
}
return;
}
if (isutyp(rt) && !isutyp(lt) &&
ln->tn_op == CON && ln->tn_val->v_quad <= 0) {
if (ln->tn_val->v_quad < 0) {
/* comparison of %s with %s, op %s */
warning(162, "negative constant", tyname(rn->tn_type),
mp->m_name);
} else if (op == GT || op == LE || (hflag && op == GE)) {
/* comparison of %s with %s, op %s */
warning(162, "0", tyname(rn->tn_type), mp->m_name);
}
return;
}
}
/*
* Takes an expression an returns 0 if this expression can be used
* for static initialisation, otherwise -1.
*
* Constant initialisation expressions must be costant or an address
* of a static object with an optional offset. In the first case,
* the result is returned in *offsp. In the second case, the static
* object is returned in *symp and the offset in *offsp.
*
* The expression can consist of PLUS, MINUS, AMPER, NAME, STRING and
* CON. Type conversions are allowed if they do not change binary
* representation (including width).
*/
int
conaddr(tnode_t *tn, sym_t **symp, ptrdiff_t *offsp)
{
sym_t *sym;
ptrdiff_t offs1, offs2;
tspec_t t, ot;
switch (tn->tn_op) {
case MINUS:
if (tn->tn_right->tn_op != CON)
return (-1);
/* FALLTHROUGH */
case PLUS:
offs1 = offs2 = 0;
if (tn->tn_left->tn_op == CON) {
offs1 = (ptrdiff_t)tn->tn_left->tn_val->v_quad;
if (conaddr(tn->tn_right, &sym, &offs2) == -1)
return (-1);
} else if (tn->tn_right->tn_op == CON) {
offs2 = (ptrdiff_t)tn->tn_right->tn_val->v_quad;
if (tn->tn_op == MINUS)
offs2 = -offs2;
if (conaddr(tn->tn_left, &sym, &offs1) == -1)
return (-1);
} else {
return (-1);
}
*symp = sym;
*offsp = offs1 + offs2;
break;
case AMPER:
if (tn->tn_left->tn_op == NAME) {
*symp = tn->tn_left->tn_sym;
*offsp = 0;
} else if (tn->tn_left->tn_op == STRING) {
/*
* If this would be the front end of a compiler we
* would return a label instead of 0.
*/
*offsp = 0;
}
break;
case CVT:
t = tn->tn_type->t_tspec;
ot = tn->tn_left->tn_type->t_tspec;
if ((!isityp(t) && t != PTR) || (!isityp(ot) && ot != PTR)) {
return (-1);
} else if (psize(t) != psize(ot)) {
return (-1);
}
if (conaddr(tn->tn_left, symp, offsp) == -1)
return (-1);
break;
default:
return (-1);
}
return (0);
}
/*
* Concatenate two string constants.
*/
strg_t *
catstrg(strg_t *strg1, strg_t *strg2)
{
size_t len1, len2, len;
if (strg1->st_tspec != strg2->st_tspec) {
/* cannot concatenate wide and regular string literals */
error(292);
return (strg1);
}
len = (len1 = strg1->st_len) + (len2 = strg2->st_len);
if (strg1->st_tspec == CHAR) {
if ((strg1->st_cp = realloc(strg1->st_cp, len + 1)) == NULL)
nomem();
(void)memcpy(strg1->st_cp + len1, strg2->st_cp, len2 + 1);
free(strg2->st_cp);
} else {
if ((strg1->st_wcp = realloc(strg1->st_wcp, (len + 1) *
sizeof (wchar_t))) == NULL)
nomem();
(void)memcpy(strg1->st_wcp + len1, strg2->st_wcp,
(len2 + 1) * sizeof (wchar_t));
free(strg2->st_wcp);
}
free(strg2);
return (strg1);
}
/*
* Print a warning if the given node has operands which should be
* parenthesized.
*
* XXX Does not work if an operand is a constant expression. Constant
* expressions are already folded.
*/
static void
precconf(tnode_t *tn)
{
tnode_t *ln, *rn;
op_t lop, rop = NOOP;
int lparn, rparn = 0;
mod_t *mp;
int warn;
if (!hflag)
return;
mp = &modtab[tn->tn_op];
lparn = 0;
for (ln = tn->tn_left; ln->tn_op == CVT; ln = ln->tn_left)
lparn |= ln->tn_parn;
lparn |= ln->tn_parn;
lop = ln->tn_op;
if (mp->m_binary) {
rparn = 0;
for (rn = tn->tn_right; tn->tn_op == CVT; rn = rn->tn_left)
rparn |= rn->tn_parn;
rparn |= rn->tn_parn;
rop = rn->tn_op;
}
warn = 0;
switch (tn->tn_op) {
case SHL:
case SHR:
if (!lparn && (lop == PLUS || lop == MINUS)) {
warn = 1;
} else if (!rparn && (rop == PLUS || rop == MINUS)) {
warn = 1;
}
break;
case LOGOR:
if (!lparn && lop == LOGAND) {
warn = 1;
} else if (!rparn && rop == LOGAND) {
warn = 1;
}
break;
case AND:
case XOR:
case OR:
if (!lparn && lop != tn->tn_op) {
if (lop == PLUS || lop == MINUS) {
warn = 1;
} else if (lop == AND || lop == XOR) {
warn = 1;
}
}
if (!warn && !rparn && rop != tn->tn_op) {
if (rop == PLUS || rop == MINUS) {
warn = 1;
} else if (rop == AND || rop == XOR) {
warn = 1;
}
}
break;
/* LINTED (enumeration values not handled in switch) */
case DECAFT:
case XORASS:
case SHLASS:
case NOOP:
case ARROW:
case ORASS:
case POINT:
case NAME:
case NOT:
case COMPL:
case CON:
case INC:
case STRING:
case DEC:
case INCBEF:
case DECBEF:
case INCAFT:
case FSEL:
case CALL:
case COMMA:
case CVT:
case ICALL:
case LOAD:
case PUSH:
case RETURN:
case INIT:
case CASE:
case FARG:
case SUBASS:
case ADDASS:
case MODASS:
case DIVASS:
case MULASS:
case ASSIGN:
case COLON:
case QUEST:
case LOGAND:
case NE:
case EQ:
case GE:
case GT:
case LE:
case LT:
case MINUS:
case PLUS:
case MOD:
case DIV:
case MULT:
case AMPER:
case STAR:
case UMINUS:
case SHRASS:
case UPLUS:
case ANDASS:
break;
}
if (warn) {
/* precedence confusion possible: parenthesize! */
warning(169);
}
}
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