From 24e25afff457839ddd78b802b42b8fceda0a6904 Mon Sep 17 00:00:00 2001 From: Katie Hockman Date: Thu, 16 Sep 2021 10:03:04 -0400 Subject: [dev.fuzz] Revert "[dev.fuzz] testing: convert seed corpus values where possible" This reverts commit 413c125da38990720744c0d98ab65c0d5b1602da. Reason for revert: Giving this more thought, we've decided that converting types under the hood may cause unexpected behavior to users. This is a feature that can always be added after more consideration has been done, but is not something that can be removed due to the backwards compatibility promise. Updates golang/go#45593 Change-Id: I79bab24979d7e4c294e6cb6455d4c7729d6a0efb Reviewed-on: https://go-review.googlesource.com/c/go/+/350251 Trust: Katie Hockman Trust: Joe Tsai Run-TryBot: Katie Hockman TryBot-Result: Go Bot Reviewed-by: Jay Conrod Reviewed-by: Joe Tsai --- src/cmd/go/testdata/script/test_fuzz.txt | 32 +++++----------------------- src/internal/fuzz/fuzz.go | 36 ++++---------------------------- src/testing/fuzz.go | 2 +- 3 files changed, 10 insertions(+), 60 deletions(-) diff --git a/src/cmd/go/testdata/script/test_fuzz.txt b/src/cmd/go/testdata/script/test_fuzz.txt index 3f825c1bc3..b1a02f46eb 100644 --- a/src/cmd/go/testdata/script/test_fuzz.txt +++ b/src/cmd/go/testdata/script/test_fuzz.txt @@ -131,23 +131,11 @@ stdout FAIL ! stdout ^ok stdout FAIL -# Test that converting compatible value from f.Add successful runs cleanly. -go test -run FuzzConvertType fuzz_add_test.go -stdout ^ok -! stdout FAIL - -# Test that converting incompatible value from f.Add fails. -! go test -run FuzzConvertIncompatibleType fuzz_add_test.go +# Test that the wrong type given with f.Add will fail. +! go test -run FuzzWrongType fuzz_add_test.go ! stdout ^ok stdout FAIL -# Test that converts value which would lose precision from f.Add. -# Consider making a test like this fail, as it may have unexpected -# consequences for the developer. -go test -v -run FuzzConvertLosePrecision fuzz_add_test.go -stdout ok -! stdout FAIL - # Test fatal with testdata seed corpus ! go test -run FuzzFail corpustesting/fuzz_testdata_corpus_test.go ! stdout ^ok @@ -391,19 +379,9 @@ func FuzzAddDifferentType(f *testing.F) { f.Fuzz(func(*testing.T, []byte) {}) } -func FuzzConvertIncompatibleType(f *testing.F) { - f.Add("abcde") - f.Fuzz(func(*testing.T, int64) {}) -} - -func FuzzConvertLosePrecision(f *testing.F) { - f.Add(-1) - f.Fuzz(func(*testing.T, uint) {}) -} - -func FuzzConvertType(f *testing.F) { - f.Add(1, "hello") - f.Fuzz(func(*testing.T, uint, []byte) {}) +func FuzzWrongType(f *testing.F) { + f.Add("hello") + f.Fuzz(func(*testing.T, []byte) {}) } -- corpustesting/fuzz_testdata_corpus_test.go -- diff --git a/src/internal/fuzz/fuzz.go b/src/internal/fuzz/fuzz.go index 99cf39e100..2cd7ebb472 100644 --- a/src/internal/fuzz/fuzz.go +++ b/src/internal/fuzz/fuzz.go @@ -942,47 +942,19 @@ func readCorpusData(data []byte, types []reflect.Type) ([]interface{}, error) { } // CheckCorpus verifies that the types in vals match the expected types -// provided. If not, attempt to convert them. If that's not possible, return an -// error. +// provided. func CheckCorpus(vals []interface{}, types []reflect.Type) error { if len(vals) != len(types) { - return fmt.Errorf("wrong number of values in corpus file: %d, want %d", len(vals), len(types)) + return fmt.Errorf("wrong number of values in corpus entry: %d, want %d", len(vals), len(types)) } for i := range types { - orig := reflect.ValueOf(vals[i]) - origType := orig.Type() - wantType := types[i] - if origType == wantType { - continue // already the same type - } - // Attempt to convert the corpus value to the expected type - if !origType.ConvertibleTo(wantType) { - return fmt.Errorf("cannot convert %v to %v", origType, wantType) - } - convertedVal, ok := convertToType(orig, wantType) - if !ok { - return fmt.Errorf("error converting %v to %v", origType, wantType) + if reflect.TypeOf(vals[i]) != types[i] { + return fmt.Errorf("mismatched types in corpus entry: %v, want %v", vals, types) } - // TODO: Check that the value didn't change. - // e.g. val went from int64(-1) -> uint(0) -> int64(0) which should fail - - // Updates vals to use the newly converted value of the expected type. - vals[i] = convertedVal.Interface() } return nil } -func convertToType(orig reflect.Value, t reflect.Type) (converted reflect.Value, ok bool) { - // Convert might panic even if ConvertibleTo returns true, so catch - // that panic and return false. - defer func() { - if r := recover(); r != nil { - ok = false - } - }() - return orig.Convert(t), true -} - // writeToCorpus atomically writes the given bytes to a new file in testdata. // If the directory does not exist, it will create one. If the file already // exists, writeToCorpus will not rewrite it. writeToCorpus returns the diff --git a/src/testing/fuzz.go b/src/testing/fuzz.go index 3a1b0bdeaa..57ea418039 100644 --- a/src/testing/fuzz.go +++ b/src/testing/fuzz.go @@ -250,7 +250,7 @@ func (f *F) TempDir() string { // Add will add the arguments to the seed corpus for the fuzz target. This will // be a no-op if called after or within the Fuzz function. The args must match -// or be convertible to those in the Fuzz function. +// those in the Fuzz function. func (f *F) Add(args ...interface{}) { var values []interface{} for i := range args { -- cgit v1.2.3-54-g00ecf