Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

strings,bytes: improve Repeat panic messages

Browse source 
The Repeat("-", maxInt) call should produce

   panic: runtime error: makeslice: len out of range

instead of

   panic: strings: Repeat output length overflow

This PR is only for theory perfection.

Change-Id: If67d87b147d666fbbb7238656f2a0cb6cf1dbb5b
GitHub-Last-Rev: 29dc0cb9c9
GitHub-Pull-Request: golang/go#67068
Reviewed-on: https://go-review.googlesource.com/c/go/+/581936
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
This commit is contained in:
go101 2024-05-03 09:56:47 +00:00 • committed by Gopher Robot
parent 2f5b420fb5
commit 44b54b99c9
4 changed files with 64 additions and 34 deletions
Download patch file Download diff file Expand all files Collapse all files

2
src/bytes/bytes.go
View file

@ -583,7 +583,7 @@ func Repeat(b []byte, count int) []byte {
if count < 0 {
panic("bytes: negative Repeat count")
}
if len(b) >= maxInt/count {
if len(b) > maxInt/count {
panic("bytes: Repeat output length overflow")
}
n := len(b) * count

35
src/bytes/bytes_test.go
View file

@ -1242,20 +1242,13 @@ func repeat(b []byte, count int) (err error) {
// See Issue golang.org/issue/16237
func TestRepeatCatchesOverflow(t *testing.T) {
tests := [...]struct {
type testCase struct {
s string
count int
errStr string
}{
0: {"--", -2147483647, "negative"},
1: {"", int(^uint(0) >> 1), ""},
2: {"-", 10, ""},
3: {"gopher", 0, ""},
4: {"-", -1, "negative"},
5: {"--", -102, "negative"},
6: {string(make([]byte, 255)), int((^uint(0))/255 + 1), "overflow"},
}
runTestCases := func(prefix string, tests []testCase) {
for i, tt := range tests {
err := repeat([]byte(tt.s), tt.count)
if tt.errStr == "" {
@ -1266,9 +1259,31 @@ func TestRepeatCatchesOverflow(t *testing.T) {
}
if err == nil || !strings.Contains(err.Error(), tt.errStr) {
t.Errorf("#%d expected %q got %q", i, tt.errStr, err)
t.Errorf("%s#%d got %q want %q", prefix, i, err, tt.errStr)
}
}
}
const maxInt = int(^uint(0) >> 1)
runTestCases("", []testCase{
0: {"--", -2147483647, "negative"},
1: {"", maxInt, ""},
2: {"-", 10, ""},
3: {"gopher", 0, ""},
4: {"-", -1, "negative"},
5: {"--", -102, "negative"},
6: {string(make([]byte, 255)), int((^uint(0))/255 + 1), "overflow"},
})
const is64Bit = 1<<(^uintptr(0)>>63)/2 != 0
if !is64Bit {
return
}
runTestCases("64-bit", []testCase{
0: {"-", maxInt, "out of range"},
})
}
func runesEqual(a, b []rune) bool {

2
src/strings/strings.go
View file

@ -570,7 +570,7 @@ func Repeat(s string, count int) string {
if count < 0 {
panic("strings: negative Repeat count")
}
if len(s) >= maxInt/count {
if len(s) > maxInt/count {
panic("strings: Repeat output length overflow")
}
n := len(s) * count

35
src/strings/strings_test.go
View file

@ -1170,20 +1170,13 @@ func repeat(s string, count int) (err error) {
// See Issue golang.org/issue/16237
func TestRepeatCatchesOverflow(t *testing.T) {
tests := [...]struct {
type testCase struct {
s string
count int
errStr string
}{
0: {"--", -2147483647, "negative"},
1: {"", int(^uint(0) >> 1), ""},
2: {"-", 10, ""},
3: {"gopher", 0, ""},
4: {"-", -1, "negative"},
5: {"--", -102, "negative"},
6: {string(make([]byte, 255)), int((^uint(0))/255 + 1), "overflow"},
}
runTestCases := func(prefix string, tests []testCase) {
for i, tt := range tests {
err := repeat(tt.s, tt.count)
if tt.errStr == "" {
@ -1194,9 +1187,31 @@ func TestRepeatCatchesOverflow(t *testing.T) {
}
if err == nil || !Contains(err.Error(), tt.errStr) {
t.Errorf("#%d expected %q got %q", i, tt.errStr, err)
t.Errorf("%s#%d got %q want %q", prefix, i, err, tt.errStr)
}
}
}
const maxInt = int(^uint(0) >> 1)
runTestCases("", []testCase{
0: {"--", -2147483647, "negative"},
1: {"", maxInt, ""},
2: {"-", 10, ""},
3: {"gopher", 0, ""},
4: {"-", -1, "negative"},
5: {"--", -102, "negative"},
6: {string(make([]byte, 255)), int((^uint(0))/255 + 1), "overflow"},
})
const is64Bit = 1<<(^uintptr(0)>>63)/2 != 0
if !is64Bit {
return
}
runTestCases("64-bit", []testCase{
0: {"-", maxInt, "out of range"},
})
}
func runesEqual(a, b []rune) bool {