Module Name: src
Committed By: rillig
Date: Thu May 26 20:17:40 UTC 2022
Modified Files:
src/tests/usr.bin/xlint/lint1: msg_132.c msg_132.exp
src/usr.bin/xlint/lint1: tree.c
Log Message:
lint: do not warn about 'uint32_t = uint64_t >> 32'
If all possible values fit into the destination type, there is no
possibility of losing accuracy.
Enhances PR 36668.
To generate a diff of this commit:
cvs rdiff -u -r1.12 -r1.13 src/tests/usr.bin/xlint/lint1/msg_132.c
cvs rdiff -u -r1.11 -r1.12 src/tests/usr.bin/xlint/lint1/msg_132.exp
cvs rdiff -u -r1.448 -r1.449 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:1.12 src/tests/usr.bin/xlint/lint1/msg_132.c:1.13
--- src/tests/usr.bin/xlint/lint1/msg_132.c:1.12 Thu May 26 19:55:57 2022
+++ src/tests/usr.bin/xlint/lint1/msg_132.c Thu May 26 20:17:40 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: msg_132.c,v 1.12 2022/05/26 19:55:57 rillig Exp $ */
+/* $NetBSD: msg_132.c,v 1.13 2022/05/26 20:17:40 rillig Exp $ */
# 3 "msg_132.c"
// Test for message: conversion from '%s' to '%s' may lose accuracy [132]
@@ -187,7 +187,6 @@ u32_t
test_ic_shr(u64_t x)
{
if (x > 3)
- /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132] */
return x >> 32;
if (x > 2)
/* expect+1: warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132] */
Index: src/tests/usr.bin/xlint/lint1/msg_132.exp
diff -u src/tests/usr.bin/xlint/lint1/msg_132.exp:1.11 src/tests/usr.bin/xlint/lint1/msg_132.exp:1.12
--- src/tests/usr.bin/xlint/lint1/msg_132.exp:1.11 Thu May 26 19:55:57 2022
+++ src/tests/usr.bin/xlint/lint1/msg_132.exp Thu May 26 20:17:40 2022
@@ -25,6 +25,5 @@ msg_132.c(99): warning: conversion from
msg_132.c(125): error: operands of '+' have incompatible types (pointer != double) [107]
msg_132.c(125): warning: function 'cover_build_plus_minus' expects to return value [214]
msg_132.c(141): warning: conversion from 'unsigned long long' to 'int' may lose accuracy [132]
-msg_132.c(191): warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132]
-msg_132.c(194): warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132]
-msg_132.c(196): warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132]
+msg_132.c(193): warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132]
+msg_132.c(195): warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132]
Index: src/usr.bin/xlint/lint1/tree.c
diff -u src/usr.bin/xlint/lint1/tree.c:1.448 src/usr.bin/xlint/lint1/tree.c:1.449
--- src/usr.bin/xlint/lint1/tree.c:1.448 Thu May 26 18:08:33 2022
+++ src/usr.bin/xlint/lint1/tree.c Thu May 26 20:17:40 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: tree.c,v 1.448 2022/05/26 18:08:33 rillig Exp $ */
+/* $NetBSD: tree.c,v 1.449 2022/05/26 20:17:40 rillig Exp $ */
/*
* Copyright (c) 1994, 1995 Jochen Pohl
@@ -37,7 +37,7 @@
#include <sys/cdefs.h>
#if defined(__RCSID)
-__RCSID("$NetBSD: tree.c,v 1.448 2022/05/26 18:08:33 rillig Exp $");
+__RCSID("$NetBSD: tree.c,v 1.449 2022/05/26 20:17:40 rillig Exp $");
#endif
#include <float.h>
@@ -105,6 +105,14 @@ static void check_precedence_confusion(t
extern sig_atomic_t fpe;
+static bool
+ic_maybe_signed(const type_t *tp, const integer_constraints *ic)
+{
+
+ return !is_uinteger(tp->t_tspec) &&
+ (ic->bclr & ((uint64_t)1 << 63)) == 0;
+}
+
static integer_constraints
ic_any(const type_t *tp)
{
@@ -192,6 +200,9 @@ ic_shl(const type_t *tp, integer_constra
integer_constraints c;
unsigned int amount;
+ if (ic_maybe_signed(tp, &a))
+ return ic_any(tp);
+
if (b.smin == b.smax && b.smin >= 0 && b.smin < 64)
amount = (unsigned int)b.smin;
else if (b.umin == b.umax && b.umin < 64)
@@ -209,6 +220,31 @@ ic_shl(const type_t *tp, integer_constra
}
static integer_constraints
+ic_shr(const type_t *tp, integer_constraints a, integer_constraints b)
+{
+ integer_constraints c;
+ unsigned int amount;
+
+ if (ic_maybe_signed(tp, &a))
+ return ic_any(tp);
+
+ if (b.smin == b.smax && b.smin >= 0 && b.smin < 64)
+ amount = (unsigned int)b.smin;
+ else if (b.umin == b.umax && b.umin < 64)
+ amount = (unsigned int)b.umin;
+ else
+ return ic_any(tp);
+
+ c.smin = INT64_MIN;
+ c.smax = INT64_MAX;
+ c.umin = 0;
+ c.umax = UINT64_MAX;
+ c.bset = a.bset >> amount;
+ c.bclr = a.bclr >> amount | ~(~(uint64_t)0 >> amount);
+ return c;
+}
+
+static integer_constraints
ic_expr(const tnode_t *tn)
{
integer_constraints lc, rc;
@@ -223,6 +259,10 @@ ic_expr(const tnode_t *tn)
lc = ic_expr(tn->tn_left);
rc = ic_expr(tn->tn_right);
return ic_shl(tn->tn_type, lc, rc);
+ case SHR:
+ lc = ic_expr(tn->tn_left);
+ rc = ic_expr(tn->tn_right);
+ return ic_shr(tn->tn_type, lc, rc);
case BITAND:
lc = ic_expr(tn->tn_left);
rc = ic_expr(tn->tn_right);
