Module Name: src
Committed By: rillig
Date: Tue Mar 12 07:56:08 UTC 2024
Modified Files:
src/tests/usr.bin/xlint/lint1: msg_132.c msg_267.c
src/usr.bin/xlint/lint1: tree.c
Log Message:
lint: fix warning about loss of conversion for unsigned bit-fields
Since decl.c 1.180 from 2021-05-02.
To generate a diff of this commit:
cvs rdiff -u -r1.34 -r1.35 src/tests/usr.bin/xlint/lint1/msg_132.c
cvs rdiff -u -r1.7 -r1.8 src/tests/usr.bin/xlint/lint1/msg_267.c
cvs rdiff -u -r1.623 -r1.624 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_132.c
diff -u src/tests/usr.bin/xlint/lint1/msg_132.c:1.34 src/tests/usr.bin/xlint/lint1/msg_132.c:1.35
--- src/tests/usr.bin/xlint/lint1/msg_132.c:1.34 Tue Mar 12 07:29:39 2024
+++ src/tests/usr.bin/xlint/lint1/msg_132.c Tue Mar 12 07:56:08 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: msg_132.c,v 1.34 2024/03/12 07:29:39 rillig Exp $ */
+/* $NetBSD: msg_132.c,v 1.35 2024/03/12 07:56:08 rillig Exp $ */
# 3 "msg_132.c"
// Test for message: conversion from '%s' to '%s' may lose accuracy [132]
@@ -410,11 +410,10 @@ fp_classify(void)
unsigned long long ext_exp:15;
} x;
- /* FIXME: There is no loss of accuracy here. */
- /* expect+1: warning: conversion from 'unsigned long long:15' to 'int:15' may lose accuracy [132] */
+ // Since decl.c 1.180 from 2021-05-02 and before tree.c 1.624 from
+ // 2024-03-12, lint warned about a possible loss of accuracy [132]
+ // when promoting a small unsigned bit-field to 'int'.
if (x.ext_exp == 0) {
- /* FIXME: There is no loss of accuracy here. */
- /* expect+1: warning: conversion from 'unsigned long long:15' to 'int:15' may lose accuracy [132] */
} else if (x.ext_exp == 0x7fff) {
}
}
Index: src/tests/usr.bin/xlint/lint1/msg_267.c
diff -u src/tests/usr.bin/xlint/lint1/msg_267.c:1.7 src/tests/usr.bin/xlint/lint1/msg_267.c:1.8
--- src/tests/usr.bin/xlint/lint1/msg_267.c:1.7 Fri Jul 7 19:45:22 2023
+++ src/tests/usr.bin/xlint/lint1/msg_267.c Tue Mar 12 07:56:08 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: msg_267.c,v 1.7 2023/07/07 19:45:22 rillig Exp $ */
+/* $NetBSD: msg_267.c,v 1.8 2024/03/12 07:56:08 rillig Exp $ */
# 3 "msg_267.c"
// Test for message: shift amount %u equals bit-size of '%s' [267]
@@ -57,20 +57,28 @@ shift_bit_field(void)
(s.bit_field >> 18) &
(s.bit_field >> 19) &
(s.bit_field >> 31) &
- /* XXX: Why 'int:18', not 'unsigned int:18'? */
- /* expect+1: warning: shift amount 32 equals bit-size of 'int:18' [267] */
+ // When promoting 'unsigned int:18', the target type is 'int', as
+ // it can represent all possible values; this is a bit misleading
+ // as its sign bit is always 0.
+ /* expect+1: warning: shift amount 32 equals bit-size of 'int:19' [267] */
(s.bit_field >> 32) &
- /* XXX: Why 'int', not 'unsigned int:18'? */
+ // When promoting 'unsigned int:18', the target type is 'int', as
+ // it can represent all possible values; this is a bit misleading
+ // as its sign bit is always 0.
/* expect+1: warning: shift amount 33 is greater than bit-size 32 of 'int' [122] */
(s.bit_field >> 33) &
(s.bit_field << 17) &
(s.bit_field << 18) &
(s.bit_field << 19) &
(s.bit_field << 31) &
- /* XXX: Why 'int:18', not 'unsigned int:18'? */
- /* expect+1: warning: shift amount 32 equals bit-size of 'int:18' [267] */
+ // When promoting 'unsigned int:18', the target type is 'int', as
+ // it can represent all possible values; this is a bit misleading
+ // as its sign bit is always 0.
+ /* expect+1: warning: shift amount 32 equals bit-size of 'int:19' [267] */
(s.bit_field << 32) &
- /* XXX: Why 'int', not 'unsigned int:18'? */
+ // When promoting 'unsigned int:18', the target type is 'int', as
+ // it can represent all possible values; this is a bit misleading
+ // as its sign bit is always 0.
/* expect+1: warning: shift amount 33 is greater than bit-size 32 of 'int' [122] */
(s.bit_field << 33) &
15;
Index: src/usr.bin/xlint/lint1/tree.c
diff -u src/usr.bin/xlint/lint1/tree.c:1.623 src/usr.bin/xlint/lint1/tree.c:1.624
--- src/usr.bin/xlint/lint1/tree.c:1.623 Sun Mar 10 19:45:14 2024
+++ src/usr.bin/xlint/lint1/tree.c Tue Mar 12 07:56:08 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: tree.c,v 1.623 2024/03/10 19:45:14 rillig Exp $ */
+/* $NetBSD: tree.c,v 1.624 2024/03/12 07:56:08 rillig Exp $ */
/*
* Copyright (c) 1994, 1995 Jochen Pohl
@@ -37,7 +37,7 @@
#include <sys/cdefs.h>
#if defined(__RCSID)
-__RCSID("$NetBSD: tree.c,v 1.623 2024/03/10 19:45:14 rillig Exp $");
+__RCSID("$NetBSD: tree.c,v 1.624 2024/03/12 07:56:08 rillig Exp $");
#endif
#include <float.h>
@@ -3256,7 +3256,8 @@ tnode_t *
promote(op_t op, bool farg, tnode_t *tn)
{
- tspec_t ot = tn->tn_type->t_tspec;
+ const type_t *otp = tn->tn_type;
+ tspec_t ot = otp->t_tspec;
if (!is_arithmetic(ot))
return tn;
@@ -3264,12 +3265,18 @@ promote(op_t op, bool farg, tnode_t *tn)
if (nt == ot)
return tn;
- type_t *ntp = expr_dup_type(tn->tn_type);
+ type_t *ntp = expr_dup_type(gettyp(nt));
ntp->t_tspec = nt;
- /*
- * Keep t_is_enum even though t_tspec gets converted from ENUM to INT,
- * so we are later able to check compatibility of enum types.
- */
+ ntp->t_is_enum = otp->t_is_enum;
+ if (ntp->t_is_enum)
+ ntp->u.enumer = otp->u.enumer;
+ ntp->t_bitfield = otp->t_bitfield;
+ if (ntp->t_bitfield) {
+ ntp->t_bit_field_width = otp->t_bit_field_width;
+ ntp->t_bit_field_offset = otp->t_bit_field_offset;
+ }
+ if (ntp->t_bitfield && is_uinteger(ot) && !is_uinteger(nt))
+ ntp->t_bit_field_width++;
return convert(op, 0, ntp, tn);
}
