Module Name: src
Committed By: rillig
Date: Mon May 30 08:14:53 UTC 2022
Modified Files:
src/tests/usr.bin/xlint/lint1: msg_168.c msg_168.exp
src/usr.bin/xlint/lint1: tree.c
Log Message:
lint: revert 'do not pre-multiply pointer expressions' from 2022-05-26
In tree.c 1.448, removing the pre-multiplication generated wrong
warnings about out-of-bounds array access.
To generate a diff of this commit:
cvs rdiff -u -r1.6 -r1.7 src/tests/usr.bin/xlint/lint1/msg_168.c \
src/tests/usr.bin/xlint/lint1/msg_168.exp
cvs rdiff -u -r1.451 -r1.452 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_168.c
diff -u src/tests/usr.bin/xlint/lint1/msg_168.c:1.6 src/tests/usr.bin/xlint/lint1/msg_168.c:1.7
--- src/tests/usr.bin/xlint/lint1/msg_168.c:1.6 Mon May 30 08:04:00 2022
+++ src/tests/usr.bin/xlint/lint1/msg_168.c Mon May 30 08:14:53 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: msg_168.c,v 1.6 2022/05/30 08:04:00 rillig Exp $ */
+/* $NetBSD: msg_168.c,v 1.7 2022/05/30 08:14:53 rillig Exp $ */
# 3 "msg_168.c"
// Test for message: array subscript cannot be > %d: %ld [168]
@@ -55,13 +55,9 @@ s_init(void)
{
struct s s[1];
s->offset_0 = 1;
- /* expect+1: warning: array subscript cannot be > 0: 1 [168] */
s->offset_1 = 2;
- /* expect+1: warning: array subscript cannot be > 0: 4 [168] */
s->offset_4 = 3;
- /* expect+1: warning: array subscript cannot be > 0: 8 [168] */
s->offset_8 = 4;
- /* expect+1: warning: array subscript cannot be > 0: 10 [168] */
s->offset_10 = 5;
return s[0];
}
Index: src/tests/usr.bin/xlint/lint1/msg_168.exp
diff -u src/tests/usr.bin/xlint/lint1/msg_168.exp:1.6 src/tests/usr.bin/xlint/lint1/msg_168.exp:1.7
--- src/tests/usr.bin/xlint/lint1/msg_168.exp:1.6 Mon May 30 08:04:00 2022
+++ src/tests/usr.bin/xlint/lint1/msg_168.exp Mon May 30 08:14:53 2022
@@ -1,6 +1,2 @@
msg_168.c(28): warning: array subscript cannot be > 19: 20 [168]
msg_168.c(41): warning: array subscript cannot be > 57: 58 [168]
-msg_168.c(59): warning: array subscript cannot be > 0: 1 [168]
-msg_168.c(61): warning: array subscript cannot be > 0: 4 [168]
-msg_168.c(63): warning: array subscript cannot be > 0: 8 [168]
-msg_168.c(65): warning: array subscript cannot be > 0: 10 [168]
Index: src/usr.bin/xlint/lint1/tree.c
diff -u src/usr.bin/xlint/lint1/tree.c:1.451 src/usr.bin/xlint/lint1/tree.c:1.452
--- src/usr.bin/xlint/lint1/tree.c:1.451 Mon May 30 07:19:28 2022
+++ src/usr.bin/xlint/lint1/tree.c Mon May 30 08:14:52 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: tree.c,v 1.451 2022/05/30 07:19:28 rillig Exp $ */
+/* $NetBSD: tree.c,v 1.452 2022/05/30 08:14:52 rillig Exp $ */
/*
* Copyright (c) 1994, 1995 Jochen Pohl
@@ -37,7 +37,7 @@
#include <sys/cdefs.h>
#if defined(__RCSID)
-__RCSID("$NetBSD: tree.c,v 1.451 2022/05/30 07:19:28 rillig Exp $");
+__RCSID("$NetBSD: tree.c,v 1.452 2022/05/30 08:14:52 rillig Exp $");
#endif
#include <float.h>
@@ -3152,7 +3152,12 @@ build_plus_minus(op_t op, bool sys, tnod
tnode_t *elsz = subt_size_in_bytes(ln->tn_type);
if (rn->tn_type->t_tspec != elsz->tn_type->t_tspec)
rn = convert(NOOP, 0, elsz->tn_type, rn);
- return new_tnode(op, sys, ln->tn_type, ln, rn);
+
+ tnode_t *prod = new_tnode(MULT, sys, rn->tn_type, rn, elsz);
+ if (rn->tn_op == CON)
+ prod = fold(prod);
+
+ return new_tnode(op, sys, ln->tn_type, ln, prod);
}
/* pointer - pointer */
@@ -3161,10 +3166,14 @@ build_plus_minus(op_t op, bool sys, tnod
lint_assert(op == MINUS);
type_t *ptrdiff = gettyp(PTRDIFF_TSPEC);
- tnode_t *diff = new_tnode(MINUS, sys, ptrdiff, ln, rn);
+ tnode_t *raw_diff = new_tnode(op, sys, ptrdiff, ln, rn);
if (ln->tn_op == CON && rn->tn_op == CON)
- diff = fold(diff);
- return diff;
+ raw_diff = fold(raw_diff);
+
+ tnode_t *elsz = subt_size_in_bytes(ln->tn_type);
+ balance(NOOP, &raw_diff, &elsz);
+
+ return new_tnode(DIV, sys, ptrdiff, raw_diff, elsz);
}
return new_tnode(op, sys, ln->tn_type, ln, rn);
@@ -4432,8 +4441,13 @@ check_expr_misc(const tnode_t *tn, bool
static void
check_array_index(tnode_t *tn, bool amper)
{
- tnode_t *ln = tn->tn_left;
- tnode_t *rn = tn->tn_right;
+ 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)
@@ -4454,8 +4468,19 @@ check_array_index(tnode_t *tn, bool ampe
if (is_incomplete(ln->tn_left->tn_type) && rn->tn_val->v_quad >= 0)
return;
- int64_t con = rn->tn_val->v_quad;
- int dim = ln->tn_left->tn_type->t_dim + (amper ? 1 : 0);
+ /* Get the size of one array element */
+ if ((elsz = length_in_bits(ln->tn_type->t_subt, NULL)) == 0)
+ return;
+ elsz /= CHAR_SIZE;
+
+ /* Change the unit of the index from bytes to element size. */
+ if (is_uinteger(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 (!is_uinteger(rn->tn_type->t_tspec) && con < 0) {
/* array subscript cannot be negative: %ld */
