Module Name: src
Committed By: rillig
Date: Sun Mar 10 10:15:52 UTC 2024
Modified Files:
src/tests/usr.bin/xlint/lint1: msg_141.c
src/usr.bin/xlint/lint1: tree.c
Log Message:
lint: fix integer overflow in integer overflow check
To generate a diff of this commit:
cvs rdiff -u -r1.11 -r1.12 src/tests/usr.bin/xlint/lint1/msg_141.c
cvs rdiff -u -r1.615 -r1.616 src/usr.bin/xlint/lint1/tree.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/tests/usr.bin/xlint/lint1/msg_141.c
diff -u src/tests/usr.bin/xlint/lint1/msg_141.c:1.11 src/tests/usr.bin/xlint/lint1/msg_141.c:1.12
--- src/tests/usr.bin/xlint/lint1/msg_141.c:1.11 Sun Mar 10 09:58:30 2024
+++ src/tests/usr.bin/xlint/lint1/msg_141.c Sun Mar 10 10:15:52 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: msg_141.c,v 1.11 2024/03/10 09:58:30 rillig Exp $ */
+/* $NetBSD: msg_141.c,v 1.12 2024/03/10 10:15:52 rillig Exp $ */
# 3 "msg_141.c"
// Test for message: operator '%s' produces integer overflow [141]
@@ -162,26 +162,26 @@ mult_u32(void)
void
mult_s64(void)
{
- /* TODO: expect+1: warning: operator '*' produces integer overflow [141] */
- //s64 = -0x100000000LL * 0x100000000LL; // -0x010000000000000000
- /* TODO: expect+1: warning: operator '*' produces integer overflow [141] */
- //s64 = -3LL * 0x2aaaaaaaaaaaaaabLL; // -0x8000000000000001
- /* TODO: expect+1: warning: operator '*' produces integer overflow [141] */
- //s64 = 0x2aaaaaaaaaaaaaabLL * -3LL; // -0x8000000000000001
+ /* expect+1: warning: operator '*' produces integer overflow [141] */
+ s64 = -0x100000000LL * 0x100000000LL; // -0x010000000000000000
+ /* expect+1: warning: operator '*' produces integer overflow [141] */
+ s64 = -3LL * 0x2aaaaaaaaaaaaaabLL; // -0x8000000000000001
+ /* expect+1: warning: operator '*' produces integer overflow [141] */
+ s64 = 0x2aaaaaaaaaaaaaabLL * -3LL; // -0x8000000000000001
s64 = -8LL * +0x1000000000000000LL; // -0x8000000000000000
s64 = +0x1000000000000000LL * -8LL; // -0x8000000000000000
s64 = +2LL * +0x3fffffffffffffffLL; // +0x7ffffffffffffffe
s64 = +0x3fffffffffffffffLL * +2LL; // +0x7ffffffffffffffe
s64 = +0x7fffffffffffffffLL * +1LL; // +0x7fffffffffffffff
s64 = +1LL * +0x7fffffffffffffffLL; // +0x7fffffffffffffff
- /* TODO: expect+1: warning: operator '*' produces integer overflow [141] */
- //s64 = +2LL * +0x4000000000000000LL; // +0x8000000000000000
- /* TODO: expect+1: warning: operator '*' produces integer overflow [141] */
- //s64 = +0x4000000000000000LL * +2LL; // +0x8000000000000000
- /* TODO: expect+1: warning: operator '*' produces integer overflow [141] */
- //s64 = +0xffffffffLL * +0x100000001LL; // +0xffffffffffffffff
- /* TODO: expect+1: warning: operator '*' produces integer overflow [141] */
- //s64 = +0x100000000LL * +0x100000000LL; // +0x010000000000000000
+ /* expect+1: warning: operator '*' produces integer overflow [141] */
+ s64 = +2LL * +0x4000000000000000LL; // +0x8000000000000000
+ /* expect+1: warning: operator '*' produces integer overflow [141] */
+ s64 = +0x4000000000000000LL * +2LL; // +0x8000000000000000
+ /* expect+1: warning: operator '*' produces integer overflow [141] */
+ s64 = +0xffffffffLL * +0x100000001LL; // +0xffffffffffffffff
+ /* expect+1: warning: operator '*' produces integer overflow [141] */
+ s64 = +0x100000000LL * +0x100000000LL; // +0x010000000000000000
}
void
@@ -249,6 +249,7 @@ mod_s32(void)
{
s32 = -1 % (-0x7fffffff - 1);
s32 = -1 % 0x7fffffff;
+ /* expect+1: warning: operator '%' produces integer overflow [141] */
s32 = (-0x7fffffff - 1) % -1;
s32 = 0x7fffffff % -1;
}
@@ -269,9 +270,8 @@ mod_s64(void)
{
s64 = -1LL % (-0x7fffffffffffffffLL - 1LL);
s64 = -1LL % 0x7fffffffffffffffLL;
- // FIXME: endless loop on x86_64 in idivq instruction,
- // probably due to SIGFPE handling.
- //s64 = (-0x7fffffffffffffffLL - 1LL) % -1LL;
+ /* expect+1: warning: operator '%' produces integer overflow [141] */
+ s64 = (-0x7fffffffffffffffLL - 1LL) % -1LL;
s64 = 0x7fffffffffffffffLL % -1LL;
}
@@ -334,12 +334,12 @@ plus_u32(void)
void
plus_s64(void)
{
- /* TODO: expect+1: warning: operator '+' produces integer overflow [141] */
- // FIXME: s64 = -0x7fffffffffffffffLL + -2LL;
+ /* expect+1: warning: operator '+' produces integer overflow [141] */
+ s64 = -0x7fffffffffffffffLL + -2LL;
s64 = -0x7fffffffffffffffLL + -1LL;
s64 = 0x7ffffffffffffffeLL + 1LL;
- /* TODO: expect+1: warning: operator '+' produces integer overflow [141] */
- // FIXME: s64 = 0x7fffffffffffffffLL + 1LL;
+ /* expect+1: warning: operator '+' produces integer overflow [141] */
+ s64 = 0x7fffffffffffffffLL + 1LL;
}
void
@@ -390,19 +390,19 @@ minus_u32(void)
void
minus_s64(void)
{
- /* TODO: expect+1: warning: operator '-' produces integer overflow [141] */
- // FIXME: s64 = -0x7fffffffffffffffLL - 0x7fffffffffffffffLL;
- /* TODO: expect+1: warning: operator '-' produces integer overflow [141] */
- // FIXME: s64 = -0x7fffffffffffffffLL - 2LL;
+ /* expect+1: warning: operator '-' produces integer overflow [141] */
+ s64 = -0x7fffffffffffffffLL - 0x7fffffffffffffffLL;
+ /* expect+1: warning: operator '-' produces integer overflow [141] */
+ s64 = -0x7fffffffffffffffLL - 2LL;
s64 = -0x7fffffffffffffffLL - 1LL;
s64 = -0x7fffffffffffffffLL - 0LL;
s64 = -0x7fffffffffffffffLL - -1LL;
s64 = 0x7fffffffffffffffLL - 1LL;
s64 = 0x7fffffffffffffffLL - 0LL;
- /* TODO: expect+1: warning: operator '-' produces integer overflow [141] */
- // FIXME: s64 = 0x7fffffffffffffffLL - -1LL;
- /* TODO: expect+1: warning: operator '-' produces integer overflow [141] */
- // FIXME: s64 = 0x7fffffffffffffffLL - -0x7fffffffffffffffLL;
+ /* expect+1: warning: operator '-' produces integer overflow [141] */
+ s64 = 0x7fffffffffffffffLL - -1LL;
+ /* expect+1: warning: operator '-' produces integer overflow [141] */
+ s64 = 0x7fffffffffffffffLL - -0x7fffffffffffffffLL;
}
void
Index: src/usr.bin/xlint/lint1/tree.c
diff -u src/usr.bin/xlint/lint1/tree.c:1.615 src/usr.bin/xlint/lint1/tree.c:1.616
--- src/usr.bin/xlint/lint1/tree.c:1.615 Sun Mar 10 09:24:54 2024
+++ src/usr.bin/xlint/lint1/tree.c Sun Mar 10 10:15:51 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: tree.c,v 1.615 2024/03/10 09:24:54 rillig Exp $ */
+/* $NetBSD: tree.c,v 1.616 2024/03/10 10:15:51 rillig Exp $ */
/*
* Copyright (c) 1994, 1995 Jochen Pohl
@@ -37,7 +37,7 @@
#include <sys/cdefs.h>
#if defined(__RCSID)
-__RCSID("$NetBSD: tree.c,v 1.615 2024/03/10 09:24:54 rillig Exp $");
+__RCSID("$NetBSD: tree.c,v 1.616 2024/03/10 10:15:51 rillig Exp $");
#endif
#include <float.h>
@@ -834,7 +834,16 @@ fold_constant_integer(tnode_t *tn)
else if (ul != 0 && si / ul != ur)
ovfl = true;
} else {
- si = sl * sr;
+ uint64_t al = sl >= 0 ? ul : -ul;
+ uint64_t ar = sr >= 0 ? ur : -ur;
+ bool neg = (sl >= 0) != (sr >= 0);
+ uint64_t max_prod = (uint64_t)max_value
+ + (neg ? 1 : 0);
+ if (al > 0 && ar > max_prod / al) {
+ si = (int64_t)(al * ar);
+ ovfl = true;
+ } else
+ si = sl * sr;
if (msb(si, t) != (msb(sl, t) ^ msb(sr, t)))
ovfl = true;
}
@@ -855,18 +864,21 @@ fold_constant_integer(tnode_t *tn)
/* modulus by 0 */
error(140);
si = 0;
+ } else if (!utyp && sl == min_value && sr == -1) {
+ ovfl = true;
+ si = 0;
} else
si = utyp ? (int64_t)(ul % ur) : sl % sr;
break;
case PLUS:
- si = utyp ? (int64_t)(ul + ur) : sl + sr;
+ si = (int64_t)(ul + ur);
if (msb(sl, t) && msb(sr, t) && !msb(si, t))
ovfl = true;
if (!utyp && !msb(sl, t) && !msb(sr, t) && msb(si, t))
ovfl = true;
break;
case MINUS:
- si = utyp ? (int64_t)(ul - ur) : sl - sr;
+ si = (int64_t)(ul - ur);
if (!utyp && msb(sl, t) && !msb(sr, t) && !msb(si, t))
ovfl = true;
if (!msb(sl, t) && msb(sr, t) && msb(si, t))
