Some useful warnings.
[rsc] --rw-rw-r-- M 84741 glenda sys 12122 Dec 11 12:22 sys/src/cmd/cc/cc.h
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/cc.h:57,62 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/cc.h:57,64
Type* type;
long lineno;
char op;
+ char oldop;
+ char xcast;
char class;
char etype;
char complex;
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/cc.h:497,502 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/cc.h:499,505
extern char typeilp[];
extern char typechl[];
extern char typechlv[];
+ extern char typechlvp[];
extern char typechlp[];
extern char typechlpfd[];
[rsc] --rw-rw-r-- M 84741 glenda sys 16058 Dec 11 12:21 sys/src/cmd/cc/cc.y
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/cc.y:656,661 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/cc.y:656,662
$$ = new(OCAST, $5, Z);
dodecl(NODECL, CXXX, $2, $3);
$$->type = lastdcl;
+ $$->xcast = 1;
}
| '(' tlist abdecor ')' '{' ilist '}' /* extension */
{
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/cc.y:760,765 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/cc.y:761,767
$$ = new(OCONST, Z, Z);
$$->type = types[TINT];
$$->vconst = $1;
+ $$->cstring = strdup(symb);
}
| LLCONST
{
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/cc.y:766,771 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/cc.y:768,774
$$ = new(OCONST, Z, Z);
$$->type = types[TLONG];
$$->vconst = $1;
+ $$->cstring = strdup(symb);
}
| LUCONST
{
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/cc.y:772,777 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/cc.y:775,781
$$ = new(OCONST, Z, Z);
$$->type = types[TUINT];
$$->vconst = $1;
+ $$->cstring = strdup(symb);
}
| LULCONST
{
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/cc.y:778,783 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/cc.y:782,788
$$ = new(OCONST, Z, Z);
$$->type = types[TULONG];
$$->vconst = $1;
+ $$->cstring = strdup(symb);
}
| LDCONST
{
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/cc.y:784,789 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/cc.y:789,795
$$ = new(OCONST, Z, Z);
$$->type = types[TDOUBLE];
$$->fconst = $1;
+ $$->cstring = strdup(symb);
}
| LFCONST
{
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/cc.y:790,795 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/cc.y:796,802
$$ = new(OCONST, Z, Z);
$$->type = types[TFLOAT];
$$->fconst = $1;
+ $$->cstring = strdup(symb);
}
| LVLCONST
{
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/cc.y:796,801 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/cc.y:803,809
$$ = new(OCONST, Z, Z);
$$->type = types[TVLONG];
$$->vconst = $1;
+ $$->cstring = strdup(symb);
}
| LUVLCONST
{
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/cc.y:802,807 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/cc.y:810,816
$$ = new(OCONST, Z, Z);
$$->type = types[TUVLONG];
$$->vconst = $1;
+ $$->cstring = strdup(symb);
}
| string
| lstring
[rsc] --rw-rw-r-- M 84741 glenda sys 22202 Dec 11 12:22 sys/src/cmd/cc/com.c
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/com.c:1,5 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/com.c:1,7
#include "cc.h"
+ int compar(Node*, int);
+
void
complex(Node *n)
{
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/com.c:985,990 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/com.c:987,994
case OHI:
ccom(l);
ccom(r);
+ if(compar(n, 0) || compar(n, 1))
+ break;
relcon(l, r);
relcon(r, l);
goto common;
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/com.c:1082,1088 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/com.c:1086,1092
*n = *l;
break;
}
- goto commun;
+ goto commute;
case OAND:
ccom(l);
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/com.c:1096,1102 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/com.c:1100,1106
break;
}
- commun:
+ commute:
/* look for commutative constant */
if(r->op == OCONST) {
if(l->op == n->op) {
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/com.c:1162,1164 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/com.c:1166,1346
evconst(n);
}
}
+
+ /* OEQ, ONE, OLE, OLS, OLT, OLO, OGE, OHS, OGT, OHI */
+ static char *cmps[12] =
+ {
+ "==", "!=", "<=", "<=", "<", "<", ">=", ">=", ">", ">",
+ };
+
+ /* 128-bit numbers */
+ typedef struct Big Big;
+ struct Big
+ {
+ vlong a;
+ uvlong b;
+ };
+ static int
+ cmp(Big x, Big y)
+ {
+ if(x.a != y.a){
+ if(x.a < y.a)
+ return -1;
+ return 1;
+ }
+ if(x.b != y.b){
+ if(x.b < y.b)
+ return -1;
+ return 1;
+ }
+ return 0;
+ }
+ static Big
+ add(Big x, int y)
+ {
+ uvlong ob;
+
+ ob = x.b;
+ x.b += y;
+ if(y > 0 && x.b < ob)
+ x.a++;
+ if(y < 0 && x.b > ob)
+ x.a--;
+ return x;
+ }
+
+ Big
+ big(vlong a, uvlong b)
+ {
+ Big x;
+
+ x.a = a;
+ x.b = b;
+ return x;
+ }
+
+ int
+ compar(Node *n, int reverse)
+ {
+ Big lo, hi, x;
+ int op;
+ char xbuf[40], cmpbuf[50];
+ Node *l, *r;
+ Type *lt, *rt;
+
+ /*
+ * The point of this function is to diagnose comparisons
+ * that can never be true or that look misleading because
+ * of the `usual arithmetic conversions'. As an example
+ * of the latter, if x is a ulong, then if(x <= -1) really means
+ * if(x <= 0xFFFFFFFF), while if(x <= -1LL) really means
+ * what it says (but 8c compiles it wrong anyway).
+ */
+
+ if(reverse){
+ r = n->left;
+ l = n->right;
+ op = comrel[relindex(n->op)];
+ }else{
+ l = n->left;
+ r = n->right;
+ op = n->op;
+ }
+
+ /*
+ * Skip over left casts to find out the original expression range.
+ */
+ while(l->op == OCAST)
+ l = l->left;
+ if(l->op == OCONST)
+ return 0;
+ lt = l->type;
+ if(l->op == ONAME){
+ lt = l->sym->type;
+ if(lt && lt->etype == TARRAY)
+ lt = lt->link;
+ }
+ if(lt == T)
+ return 0;
+ if(lt->etype == TXXX || lt->etype > TUVLONG)
+ return 0;
+
+ /*
+ * Skip over the right casts to find the on-screen value.
+ */
+ if(r->op != OCONST)
+ return 0;
+ while(r->oldop == OCAST && !r->xcast)
+ r = r->left;
+ rt = r->type;
+ if(rt == T)
+ return 0;
+
+ x.b = r->vconst;
+ x.a = 0;
+ if((rt->etype&1) && r->vconst < 0) /* signed negative */
+ x.a = ~0ULL;
+
+ if((lt->etype&1)==0){
+ /* unsigned */
+ lo = big(0, 0);
+ if(lt->width == 8)
+ hi = big(0, ~0ULL);
+ else
+ hi = big(0, (1LL<<(l->type->width*8))-1);
+ }else{
+ lo = big(~0ULL, -(1LL<<(l->type->width*8-1)));
+ hi = big(0, (1LL<<(l->type->width*8-1))-1);
+ }
+
+ switch(op){
+ case OLT:
+ case OLO:
+ case OGE:
+ case OHS:
+ if(cmp(x, lo) <= 0)
+ goto useless;
+ if(cmp(x, add(hi, 1)) >= 0)
+ goto useless;
+ break;
+ case OLE:
+ case OLS:
+ case OGT:
+ case OHI:
+ if(cmp(x, add(lo, -1)) <= 0)
+ goto useless;
+ if(cmp(x, hi) >= 0)
+ goto useless;
+ break;
+ case OEQ:
+ case ONE:
+ /*
+ * Don't warn about comparisons if the expression
+ * is as wide as the value: the compiler-supplied casts
+ * will make both outcomes possible.
+ */
+ if(lt->width >= rt->width && debug['w'] < 2)
+ return 0;
+ if(cmp(x, lo) < 0 || cmp(x, hi) > 0)
+ goto useless;
+ break;
+ }
+ return 0;
+
+ useless:
+ if((x.a==0 && x.b<=9) || (x.a==~0LL && x.b >= -9ULL))
+ snprint(xbuf, sizeof xbuf, "%lld", x.b);
+ else if(x.a == 0)
+ snprint(xbuf, sizeof xbuf, "%#llux", x.b);
+ else
+ snprint(xbuf, sizeof xbuf, "%#llx", x.b);
+ if(reverse)
+ snprint(cmpbuf, sizeof cmpbuf, "%s %s %T",
+ xbuf, cmps[relindex(n->op)], lt);
+ else
+ snprint(cmpbuf, sizeof cmpbuf, "%T %s %s",
+ lt, cmps[relindex(n->op)], xbuf);
+ warn(n, "useless or misleading comparison: %s", cmpbuf);
+ return 0;
+ }
+
[rsc] --rw-rw-r-- M 84741 glenda sys 23923 Dec 11 12:22 sys/src/cmd/cc/lex.c
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/lex.c:395,401 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/lex.c:395,401
yylex(void)
{
vlong vv;
- long c, c1;
+ long c, c1, t;
char *cp;
Rune rune;
Sym *s;
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/lex.c:540,547 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/lex.c:540,549
if(yylval.vval != vv)
yyerror("overflow in character constant: 0x%lx", c);
else
- if(c & 0x80)
+ if(c & 0x80){
+ nearln = lineno;
warn(Z, "sign-extended character constant");
+ }
yylval.vval = convvtox(vv, TCHAR);
return LCONST;
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/lex.c:784,828 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/lex.c:786,827
if(mpatov(symb, &yylval.vval))
yyerror("overflow in constant");
+ vv = yylval.vval;
if(c1 & Numvlong) {
- if(c1 & Numuns) {
+ if((c1 & Numuns) || convvtox(vv, TVLONG) < 0) {
c = LUVLCONST;
+ t = TUVLONG;
goto nret;
}
- yylval.vval = convvtox(yylval.vval, TVLONG);
- if(yylval.vval < 0) {
- c = LUVLCONST;
- goto nret;
- }
c = LVLCONST;
+ t = TVLONG;
goto nret;
}
if(c1 & Numlong) {
- if(c1 & Numuns) {
+ if((c1 & Numuns) || convvtox(vv, TLONG) < 0) {
c = LULCONST;
+ t = TULONG;
goto nret;
}
- yylval.vval = convvtox(yylval.vval, TLONG);
- if(yylval.vval < 0) {
- c = LULCONST;
- goto nret;
- }
c = LLCONST;
+ t = TLONG;
goto nret;
}
- if(c1 & Numuns) {
+ if((c1 & Numuns) || convvtox(vv, TINT) < 0) {
c = LUCONST;
+ t = TUINT;
goto nret;
}
- yylval.vval = convvtox(yylval.vval, TINT);
- if(yylval.vval < 0) {
- c = LUCONST;
- goto nret;
- }
c = LCONST;
+ t = TINT;
goto nret;
nret:
+ yylval.vval = convvtox(vv, t);
+ if(yylval.vval != vv){
+ nearln = lineno;
+ warn(Z, "truncated constant: %T %s", types[t], symb);
+ }
return c;
casedot:
[rsc] --rw-rw-r-- M 84741 jmk sys 8645 Dec 11 12:22 sys/src/cmd/cc/scon.c
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/scon.c:226,231 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/scon.c:226,232
} else {
n->vconst = convvtox(v, n->type->etype);
}
+ n->oldop = n->op;
n->op = OCONST;
}
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/scon.c:375,380 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/scon.c:376,382
}
c1 = trm[0].mult;
if(j == 0) {
+ n->oldop = n->op;
n->op = OCONST;
n->vconst = c1;
return;
[rsc] --rw-rw-r-- M 84741 glenda sys 34315 Dec 11 12:22 sys/src/cmd/cc/sub.c
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/sub.c:1484,1489 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/sub.c:1484,1490
-1, 0, 0,
};
+ /* OEQ, ONE, OLE, OLS, OLT, OLO, OGE, OHS, OGT, OHI */
char comrel[12] =
{
ONE, OEQ, OGT, OHI, OGE, OHS, OLT, OLO, OLE, OLS,
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/sub.c:1522,1527 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/sub.c:1523,1529
char typechl[NTYPE];
char typechlv[NTYPE];
+ char typechlvp[NTYPE];
int typechlinit[] =
{
TCHAR, TUCHAR, TSHORT, TUSHORT, TINT, TUINT, TLONG, TULONG, -1,
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/sub.c:1868,1877 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/sub.c:1870,1881
urk("typechl", nelem(typechl), typechlinit[i]);
typechl[typechlinit[i]] = 1;
typechlv[typechlinit[i]] = 1;
+ typechlvp[typechlinit[i]] = 1;
}
for(i=0; typechlpinit[i] >= 0; i++) {
urk("typechlp", nelem(typechlp), typechlpinit[i]);
typechlp[typechlpinit[i]] = 1;
+ typechlvp[typechlinit[i]] = 1;
}
for(i=0; typechlpfdinit[i] >= 0; i++) {
urk("typechlpfd", nelem(typechlpfd), typechlpfdinit[i]);
/n/sourcesdump/2005/1211/plan9/sys/src/cmd/cc/sub.c:1893,1898 -
/n/sourcesdump/2005/1212/plan9/sys/src/cmd/cc/sub.c:1897,1903
urk("typev", nelem(typev), typevinit[i]);
typev[typevinit[i]] = 1;
typechlv[typevinit[i]] = 1;
+ typechlvp[typechlinit[i]] = 1;
}
for(i=0; typefdinit[i] >= 0; i++) {
urk("typefd", nelem(typefd), typefdinit[i]);
|
