// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This file contains tests for the printf checker.
package print
import (
"fmt"
logpkg "log" // renamed to make it harder to see
"math"
"os"
"testing"
"unsafe" // just for test case printing unsafe.Pointer
// For testing printf-like functions from external package.
// "github.com/foobar/externalprintf"
)
func UnsafePointerPrintfTest() {
var up unsafe.Pointer
fmt.Printf("%p, %x %X", up, up, up)
}
// Error methods that do not satisfy the Error interface and should be checked.
type errorTest1 int
func (errorTest1) Error(...interface{}) string {
return "hi"
}
type errorTest2 int // Analogous to testing's *T type.
func (errorTest2) Error(...interface{}) {
}
type errorTest3 int
func (errorTest3) Error() { // No return value.
}
type errorTest4 int
func (errorTest4) Error() int { // Different return type.
return 3
}
type errorTest5 int
func (errorTest5) error() { // niladic; don't complain if no args (was bug)
}
// This function never executes, but it serves as a simple test for the program.
// Test with make test.
func PrintfTests() {
var b bool
var i int
var r rune
var s string
var x float64
var p *int
var imap map[int]int
var fslice []float64
var c complex64
// Some good format/argtypes
fmt.Printf("")
fmt.Printf("%b %b %b", 3, i, x)
fmt.Printf("%c %c %c %c", 3, i, 'x', r)
fmt.Printf("%d %d %d", 3, i, imap)
fmt.Printf("%e %e %e %e", 3e9, x, fslice, c)
fmt.Printf("%E %E %E %E", 3e9, x, fslice, c)
fmt.Printf("%f %f %f %f", 3e9, x, fslice, c)
fmt.Printf("%F %F %F %F", 3e9, x, fslice, c)
fmt.Printf("%g %g %g %g", 3e9, x, fslice, c)
fmt.Printf("%G %G %G %G", 3e9, x, fslice, c)
fmt.Printf("%b %b %b %b", 3e9, x, fslice, c)
fmt.Printf("%o %o", 3, i)
fmt.Printf("%p", p)
fmt.Printf("%q %q %q %q", 3, i, 'x', r)
fmt.Printf("%s %s %s", "hi", s, []byte{65})
fmt.Printf("%t %t", true, b)
fmt.Printf("%T %T", 3, i)
fmt.Printf("%U %U", 3, i)
fmt.Printf("%v %v", 3, i)
fmt.Printf("%x %x %x %x", 3, i, "hi", s)
fmt.Printf("%X %X %X %X", 3, i, "hi", s)
fmt.Printf("%.*s %d %g", 3, "hi", 23, 2.3)
fmt.Printf("%s", &stringerv)
fmt.Printf("%v", &stringerv)
fmt.Printf("%T", &stringerv)
fmt.Printf("%s", &embeddedStringerv)
fmt.Printf("%v", &embeddedStringerv)
fmt.Printf("%T", &embeddedStringerv)
fmt.Printf("%v", notstringerv)
fmt.Printf("%T", notstringerv)
fmt.Printf("%q", stringerarrayv)
fmt.Printf("%v", stringerarrayv)
fmt.Printf("%s", stringerarrayv)
fmt.Printf("%v", notstringerarrayv)
fmt.Printf("%T", notstringerarrayv)
fmt.Printf("%d", new(fmt.Formatter))
fmt.Printf("%*%", 2) // Ridiculous but allowed.
fmt.Printf("%s", interface{}(nil)) // Nothing useful we can say.
fmt.Printf("%g", 1+2i)
fmt.Printf("%#e %#E %#f %#F %#g %#G", 1.2, 1.2, 1.2, 1.2, 1.2, 1.2) // OK since Go 1.9
// Some bad format/argTypes
fmt.Printf("%b", "hi") // ERROR "Printf format %b has arg \x22hi\x22 of wrong type string"
fmt.Printf("%t", c) // ERROR "Printf format %t has arg c of wrong type complex64"
fmt.Printf("%t", 1+2i) // ERROR "Printf format %t has arg 1 \+ 2i of wrong type complex128"
fmt.Printf("%c", 2.3) // ERROR "Printf format %c has arg 2.3 of wrong type float64"
fmt.Printf("%d", 2.3) // ERROR "Printf format %d has arg 2.3 of wrong type float64"
fmt.Printf("%e", "hi") // ERROR "Printf format %e has arg \x22hi\x22 of wrong type string"
fmt.Printf("%E", true) // ERROR "Printf format %E has arg true of wrong type bool"
fmt.Printf("%f", "hi") // ERROR "Printf format %f has arg \x22hi\x22 of wrong type string"
fmt.Printf("%F", 'x') // ERROR "Printf format %F has arg 'x' of wrong type rune"
fmt.Printf("%g", "hi") // ERROR "Printf format %g has arg \x22hi\x22 of wrong type string"
fmt.Printf("%g", imap) // ERROR "Printf format %g has arg imap of wrong type map\[int\]int"
fmt.Printf("%G", i) // ERROR "Printf format %G has arg i of wrong type int"
fmt.Printf("%o", x) // ERROR "Printf format %o has arg x of wrong type float64"
fmt.Printf("%p", nil) // ERROR "Printf format %p has arg nil of wrong type untyped nil"
fmt.Printf("%p", 23) // ERROR "Printf format %p has arg 23 of wrong type int"
fmt.Printf("%q", x) // ERROR "Printf format %q has arg x of wrong type float64"
fmt.Printf("%s", b) // ERROR "Printf format %s has arg b of wrong type bool"
fmt.Printf("%s", byte(65)) // ERROR "Printf format %s has arg byte\(65\) of wrong type byte"
fmt.Printf("%t", 23) // ERROR "Printf format %t has arg 23 of wrong type int"
fmt.Printf("%U", x) // ERROR "Printf format %U has arg x of wrong type float64"
fmt.Printf("%x", nil) // ERROR "Printf format %x has arg nil of wrong type untyped nil"
fmt.Printf("%X", 2.3) // ERROR "Printf format %X has arg 2.3 of wrong type float64"
fmt.Printf("%s", stringerv) // ERROR "Printf format %s has arg stringerv of wrong type .*print.ptrStringer"
fmt.Printf("%t", stringerv) // ERROR "Printf format %t has arg stringerv of wrong type .*print.ptrStringer"
fmt.Printf("%s", embeddedStringerv) // ERROR "Printf format %s has arg embeddedStringerv of wrong type .*print.embeddedStringer"
fmt.Printf("%t", embeddedStringerv) // ERROR "Printf format %t has arg embeddedStringerv of wrong type .*print.embeddedStringer"
fmt.Printf("%q", notstringerv) // ERROR "Printf format %q has arg notstringerv of wrong type .*print.notstringer"
fmt.Printf("%t", notstringerv) // ERROR "Printf format %t has arg notstringerv of wrong type .*print.notstringer"
fmt.Printf("%t", stringerarrayv) // ERROR "Printf format %t has arg stringerarrayv of wrong type .*print.stringerarray"
fmt.Printf("%t", notstringerarrayv) // ERROR "Printf format %t has arg notstringerarrayv of wrong type .*print.notstringerarray"
fmt.Printf("%q", notstringerarrayv) // ERROR "Printf format %q has arg notstringerarrayv of wrong type .*print.notstringerarray"
fmt.Printf("%d", BoolFormatter(true)) // ERROR "Printf format %d has arg BoolFormatter\(true\) of wrong type .*print.BoolFormatter"
fmt.Printf("%z", FormatterVal(true)) // correct (the type is responsible for formatting)
fmt.Printf("%d", FormatterVal(true)) // correct (the type is responsible for formatting)
fmt.Printf("%s", nonemptyinterface) // correct (the type is responsible for formatting)
fmt.Printf("%.*s %d %6g", 3, "hi", 23, 'x') // ERROR "Printf format %6g has arg 'x' of wrong type rune"
fmt.Println() // not an error
fmt.Println("%s", "hi") // ERROR "Println call has possible formatting directive %s"
fmt.Println("%v", "hi") // ERROR "Println call has possible formatting directive %v"
fmt.Println("%T", "hi") // ERROR "Println call has possible formatting directive %T"
fmt.Println("0.0%") // correct (trailing % couldn't be a formatting directive)
fmt.Printf("%s", "hi", 3) // ERROR "Printf call needs 1 arg but has 2 args"
_ = fmt.Sprintf("%"+("s"), "hi", 3) // ERROR "Sprintf call needs 1 arg but has 2 args"
fmt.Printf("%s%%%d", "hi", 3) // correct
fmt.Printf("%08s", "woo") // correct
fmt.Printf("% 8s", "woo") // correct
fmt.Printf("%.*d", 3, 3) // correct
fmt.Printf("%.*d x", 3, 3, 3, 3) // ERROR "Printf call needs 2 args but has 4 args"
fmt.Printf("%.*d x", "hi", 3) // ERROR "Printf format %.*d uses non-int \x22hi\x22 as argument of \*"
fmt.Printf("%.*d x", i, 3) // correct
fmt.Printf("%.*d x", s, 3) // ERROR "Printf format %.\*d uses non-int s as argument of \*"
fmt.Printf("%*% x", 0.22) // ERROR "Printf format %\*% uses non-int 0.22 as argument of \*"
fmt.Printf("%q %q", multi()...) // ok
fmt.Printf("%#q", `blah`) // ok
// printf("now is the time", "buddy") // no error "printf call has arguments but no formatting directives"
Printf("now is the time", "buddy") // ERROR "Printf call has arguments but no formatting directives"
Printf("hi") // ok
const format = "%s %s\n"
Printf(format, "hi", "there")
Printf(format, "hi") // ERROR "Printf format %s reads arg #2, but call has 1 arg$"
Printf("%s %d %.3v %q", "str", 4) // ERROR "Printf format %.3v reads arg #3, but call has 2 args"
f := new(ptrStringer)
f.Warn(0, "%s", "hello", 3) // ERROR "Warn call has possible formatting directive %s"
f.Warnf(0, "%s", "hello", 3) // ERROR "Warnf call needs 1 arg but has 2 args"
f.Warnf(0, "%r", "hello") // ERROR "Warnf format %r has unknown verb r"
f.Warnf(0, "%#s", "hello") // ERROR "Warnf format %#s has unrecognized flag #"
f.Warn2(0, "%s", "hello", 3) // ERROR "Warn2 call has possible formatting directive %s"
f.Warnf2(0, "%s", "hello", 3) // ERROR "Warnf2 call needs 1 arg but has 2 args"
f.Warnf2(0, "%r", "hello") // ERROR "Warnf2 format %r has unknown verb r"
f.Warnf2(0, "%#s", "hello") // ERROR "Warnf2 format %#s has unrecognized flag #"
f.Wrap(0, "%s", "hello", 3) // ERROR "Wrap call has possible formatting directive %s"
f.Wrapf(0, "%s", "hello", 3) // ERROR "Wrapf call needs 1 arg but has 2 args"
f.Wrapf(0, "%r", "hello") // ERROR "Wrapf format %r has unknown verb r"
f.Wrapf(0, "%#s", "hello") // ERROR "Wrapf format %#s has unrecognized flag #"
f.Wrap2(0, "%s", "hello", 3) // ERROR "Wrap2 call has possible formatting directive %s"
f.Wrapf2(0, "%s", "hello", 3) // ERROR "Wrapf2 call needs 1 arg but has 2 args"
f.Wrapf2(0, "%r", "hello") // ERROR "Wrapf2 format %r has unknown verb r"
f.Wrapf2(0, "%#s", "hello") // ERROR "Wrapf2 format %#s has unrecognized flag #"
fmt.Printf("%#s", FormatterVal(true)) // correct (the type is responsible for formatting)
Printf("d%", 2) // ERROR "Printf format % is missing verb at end of string"
Printf("%d", percentDV)
Printf("%d", &percentDV)
Printf("%d", notPercentDV) // ERROR "Printf format %d has arg notPercentDV of wrong type .*print.notPercentDStruct"
Printf("%d", ¬PercentDV) // ERROR "Printf format %d has arg ¬PercentDV of wrong type \*.*print.notPercentDStruct"
Printf("%p", ¬PercentDV) // Works regardless: we print it as a pointer.
Printf("%q", &percentDV) // ERROR "Printf format %q has arg &percentDV of wrong type \*.*print.percentDStruct"
Printf("%s", percentSV)
Printf("%s", &percentSV)
// Good argument reorderings.
Printf("%[1]d", 3)
Printf("%[1]*d", 3, 1)
Printf("%[2]*[1]d", 1, 3)
Printf("%[2]*.[1]*[3]d", 2, 3, 4)
fmt.Fprintf(os.Stderr, "%[2]*.[1]*[3]d", 2, 3, 4) // Use Fprintf to make sure we count arguments correctly.
// Bad argument reorderings.
Printf("%[xd", 3) // ERROR "Printf format %\[xd is missing closing \]"
Printf("%[x]d x", 3) // ERROR "Printf format has invalid argument index \[x\]"
Printf("%[3]*s x", "hi", 2) // ERROR "Printf format has invalid argument index \[3\]"
_ = fmt.Sprintf("%[3]d x", 2) // ERROR "Sprintf format has invalid argument index \[3\]"
Printf("%[2]*.[1]*[3]d x", 2, "hi", 4) // ERROR "Printf format %\[2]\*\.\[1\]\*\[3\]d uses non-int \x22hi\x22 as argument of \*"
Printf("%[0]s x", "arg1") // ERROR "Printf format has invalid argument index \[0\]"
Printf("%[0]d x", 1) // ERROR "Printf format has invalid argument index \[0\]"
// Something that satisfies the error interface.
var e error
fmt.Println(e.Error()) // ok
// Something that looks like an error interface but isn't, such as the (*T).Error method
// in the testing package.
var et1 *testing.T
et1.Error() // ok
et1.Error("hi") // ok
et1.Error("%d", 3) // ERROR "Error call has possible formatting directive %d"
var et3 errorTest3
et3.Error() // ok, not an error method.
var et4 errorTest4
et4.Error() // ok, not an error method.
var et5 errorTest5
et5.error() // ok, not an error method.
// Interfaces can be used with any verb.
var iface interface {
ToTheMadness() bool // Method ToTheMadness usually returns false
}
fmt.Printf("%f", iface) // ok: fmt treats interfaces as transparent and iface may well have a float concrete type
// Can't print a function.
Printf("%d", someFunction) // ERROR "Printf format %d arg someFunction is a func value, not called"
Printf("%v", someFunction) // ERROR "Printf format %v arg someFunction is a func value, not called"
Println(someFunction) // ERROR "Println arg someFunction is a func value, not called"
Printf("%p", someFunction) // ok: maybe someone wants to see the pointer
Printf("%T", someFunction) // ok: maybe someone wants to see the type
// Bug: used to recur forever.
Printf("%p %x", recursiveStructV, recursiveStructV.next)
Printf("%p %x", recursiveStruct1V, recursiveStruct1V.next) // ERROR "Printf format %x has arg recursiveStruct1V\.next of wrong type \*.*print\.RecursiveStruct2"
Printf("%p %x", recursiveSliceV, recursiveSliceV)
Printf("%p %x", recursiveMapV, recursiveMapV)
// Special handling for Log.
math.Log(3) // OK
var t *testing.T
t.Log("%d", 3) // ERROR "Log call has possible formatting directive %d"
t.Logf("%d", 3)
t.Logf("%d", "hi") // ERROR "Logf format %d has arg \x22hi\x22 of wrong type string"
Errorf(1, "%d", 3) // OK
Errorf(1, "%d", "hi") // ERROR "Errorf format %d has arg \x22hi\x22 of wrong type string"
// Multiple string arguments before variadic args
errorf("WARNING", "foobar") // OK
errorf("INFO", "s=%s, n=%d", "foo", 1) // OK
errorf("ERROR", "%d") // ERROR "errorf format %d reads arg #1, but call has 0 args"
// Printf from external package
// externalprintf.Printf("%d", 42) // OK
// externalprintf.Printf("foobar") // OK
// level := 123
// externalprintf.Logf(level, "%d", 42) // OK
// externalprintf.Errorf(level, level, "foo %q bar", "foobar") // OK
// externalprintf.Logf(level, "%d") // no error "Logf format %d reads arg #1, but call has 0 args"
// var formatStr = "%s %s"
// externalprintf.Sprintf(formatStr, "a", "b") // OK
// externalprintf.Logf(level, formatStr, "a", "b") // OK
// user-defined Println-like functions
ss := &someStruct{}
ss.Log(someFunction, "foo") // OK
ss.Error(someFunction, someFunction) // OK
ss.Println() // OK
ss.Println(1.234, "foo") // OK
ss.Println(1, someFunction) // no error "Println arg someFunction is a func value, not called"
ss.log(someFunction) // OK
ss.log(someFunction, "bar", 1.33) // OK
ss.log(someFunction, someFunction) // no error "log arg someFunction is a func value, not called"
// indexed arguments
Printf("%d %[3]d %d %[2]d x", 1, 2, 3, 4) // OK
Printf("%d %[0]d %d %[2]d x", 1, 2, 3, 4) // ERROR "Printf format has invalid argument index \[0\]"
Printf("%d %[3]d %d %[-2]d x", 1, 2, 3, 4) // ERROR "Printf format has invalid argument index \[-2\]"
Printf("%d %[3]d %d %[2234234234234]d x", 1, 2, 3, 4) // ERROR "Printf format has invalid argument index \[2234234234234\]"
Printf("%d %[3]d %-10d %[2]d x", 1, 2, 3) // ERROR "Printf format %-10d reads arg #4, but call has 3 args"
Printf("%[1][3]d x", 1, 2) // ERROR "Printf format %\[1\]\[ has unknown verb \["
Printf("%[1]d x", 1, 2) // OK
Printf("%d %[3]d %d %[2]d x", 1, 2, 3, 4, 5) // OK
// wrote Println but meant Fprintln
Printf("%p\n", os.Stdout) // OK
Println(os.Stdout, "hello") // ERROR "Println does not take io.Writer but has first arg os.Stdout"
Printf(someString(), "hello") // OK
// Printf wrappers in package log should be detected automatically
logpkg.Fatal("%d", 1) // ERROR "Fatal call has possible formatting directive %d"
logpkg.Fatalf("%d", "x") // ERROR "Fatalf format %d has arg \x22x\x22 of wrong type string"
logpkg.Fatalln("%d", 1) // ERROR "Fatalln call has possible formatting directive %d"
logpkg.Panic("%d", 1) // ERROR "Panic call has possible formatting directive %d"
logpkg.Panicf("%d", "x") // ERROR "Panicf format %d has arg \x22x\x22 of wrong type string"
logpkg.Panicln("%d", 1) // ERROR "Panicln call has possible formatting directive %d"
logpkg.Print("%d", 1) // ERROR "Print call has possible formatting directive %d"
logpkg.Printf("%d", "x") // ERROR "Printf format %d has arg \x22x\x22 of wrong type string"
logpkg.Println("%d", 1) // ERROR "Println call has possible formatting directive %d"
// Methods too.
var l *logpkg.Logger
l.Fatal("%d", 1) // ERROR "Fatal call has possible formatting directive %d"
l.Fatalf("%d", "x") // ERROR "Fatalf format %d has arg \x22x\x22 of wrong type string"
l.Fatalln("%d", 1) // ERROR "Fatalln call has possible formatting directive %d"
l.Panic("%d", 1) // ERROR "Panic call has possible formatting directive %d"
l.Panicf("%d", "x") // ERROR "Panicf format %d has arg \x22x\x22 of wrong type string"
l.Panicln("%d", 1) // ERROR "Panicln call has possible formatting directive %d"
l.Print("%d", 1) // ERROR "Print call has possible formatting directive %d"
l.Printf("%d", "x") // ERROR "Printf format %d has arg \x22x\x22 of wrong type string"
l.Println("%d", 1) // ERROR "Println call has possible formatting directive %d"
// Issue 26486
dbg("", 1) // no error "call has arguments but no formatting directive"
}
func someString() string { return "X" }
type someStruct struct{}
// Log is non-variadic user-define Println-like function.
// Calls to this func must be skipped when checking
// for Println-like arguments.
func (ss *someStruct) Log(f func(), s string) {}
// Error is variadic user-define Println-like function.
// Calls to this func mustn't be checked for Println-like arguments,
// since variadic arguments type isn't interface{}.
func (ss *someStruct) Error(args ...func()) {}
// Println is variadic user-defined Println-like function.
// Calls to this func must be checked for Println-like arguments.
func (ss *someStruct) Println(args ...interface{}) {}
// log is variadic user-defined Println-like function.
// Calls to this func must be checked for Println-like arguments.
func (ss *someStruct) log(f func(), args ...interface{}) {}
// A function we use as a function value; it has no other purpose.
func someFunction() {}
// Printf is used by the test so we must declare it.
func Printf(format string, args ...interface{}) {
fmt.Printf(format, args...)
}
// Println is used by the test so we must declare it.
func Println(args ...interface{}) {
fmt.Println(args...)
}
// printf is used by the test so we must declare it.
func printf(format string, args ...interface{}) {
fmt.Printf(format, args...)
}
// Errorf is used by the test for a case in which the first parameter
// is not a format string.
func Errorf(i int, format string, args ...interface{}) {
_ = fmt.Errorf(format, args...)
}
// errorf is used by the test for a case in which the function accepts multiple
// string parameters before variadic arguments
func errorf(level, format string, args ...interface{}) {
_ = fmt.Errorf(format, args...)
}
// multi is used by the test.
func multi() []interface{} {
panic("don't call - testing only")
}
type stringer int
func (stringer) String() string { return "string" }
type ptrStringer float64
var stringerv ptrStringer
func (*ptrStringer) String() string {
return "string"
}
func (p *ptrStringer) Warn2(x int, args ...interface{}) string {
return p.Warn(x, args...)
}
func (p *ptrStringer) Warnf2(x int, format string, args ...interface{}) string {
return p.Warnf(x, format, args...)
}
func (*ptrStringer) Warn(x int, args ...interface{}) string {
return "warn"
}
func (*ptrStringer) Warnf(x int, format string, args ...interface{}) string {
return "warnf"
}
func (p *ptrStringer) Wrap2(x int, args ...interface{}) string {
return p.Wrap(x, args...)
}
func (p *ptrStringer) Wrapf2(x int, format string, args ...interface{}) string {
return p.Wrapf(x, format, args...)
}
func (*ptrStringer) Wrap(x int, args ...interface{}) string {
return fmt.Sprint(args...)
}
func (*ptrStringer) Wrapf(x int, format string, args ...interface{}) string {
return fmt.Sprintf(format, args...)
}
func (*ptrStringer) BadWrap(x int, args ...interface{}) string {
return fmt.Sprint(args) // ERROR "missing ... in args forwarded to print-like function"
}
func (*ptrStringer) BadWrapf(x int, format string, args ...interface{}) string {
return fmt.Sprintf(format, args) // ERROR "missing ... in args forwarded to printf-like function"
}
func (*ptrStringer) WrapfFalsePositive(x int, arg1 string, arg2 ...interface{}) string {
return fmt.Sprintf("%s %v", arg1, arg2)
}
type embeddedStringer struct {
foo string
ptrStringer
bar int
}
var embeddedStringerv embeddedStringer
type notstringer struct {
f float64
}
var notstringerv notstringer
type stringerarray [4]float64
func (stringerarray) String() string {
return "string"
}
var stringerarrayv stringerarray
type notstringerarray [4]float64
var notstringerarrayv notstringerarray
var nonemptyinterface = interface {
f()
}(nil)
// A data type we can print with "%d".
type percentDStruct struct {
a int
b []byte
c *float64
}
var percentDV percentDStruct
// A data type we cannot print correctly with "%d".
type notPercentDStruct struct {
a int
b []byte
c bool
}
var notPercentDV notPercentDStruct
// A data type we can print with "%s".
type percentSStruct struct {
a string
b []byte
C stringerarray
}
var percentSV percentSStruct
type recursiveStringer int
func (s recursiveStringer) String() string {
_ = fmt.Sprintf("%d", s)
_ = fmt.Sprintf("%#v", s)
_ = fmt.Sprintf("%v", s) // ERROR "Sprintf format %v with arg s causes recursive String method call"
_ = fmt.Sprintf("%v", &s) // ERROR "Sprintf format %v with arg &s causes recursive String method call"
_ = fmt.Sprintf("%T", s) // ok; does not recursively call String
return fmt.Sprintln(s) // ERROR "Sprintln arg s causes recursive call to String method"
}
type recursivePtrStringer int
func (p *recursivePtrStringer) String() string {
_ = fmt.Sprintf("%v", *p)
_ = fmt.Sprint(&p) // ok; prints address
return fmt.Sprintln(p) // ERROR "Sprintln arg p causes recursive call to String method"
}
type BoolFormatter bool
func (*BoolFormatter) Format(fmt.State, rune) {
}
// Formatter with value receiver
type FormatterVal bool
func (FormatterVal) Format(fmt.State, rune) {
}
type RecursiveSlice []RecursiveSlice
var recursiveSliceV = &RecursiveSlice{}
type RecursiveMap map[int]RecursiveMap
var recursiveMapV = make(RecursiveMap)
type RecursiveStruct struct {
next *RecursiveStruct
}
var recursiveStructV = &RecursiveStruct{}
type RecursiveStruct1 struct {
next *RecursiveStruct2
}
type RecursiveStruct2 struct {
next *RecursiveStruct1
}
var recursiveStruct1V = &RecursiveStruct1{}
type unexportedInterface struct {
f interface{}
}
// Issue 17798: unexported ptrStringer cannot be formatted.
type unexportedStringer struct {
t ptrStringer
}
type unexportedStringerOtherFields struct {
s string
t ptrStringer
S string
}
// Issue 17798: unexported error cannot be formatted.
type unexportedError struct {
e error
}
type unexportedErrorOtherFields struct {
s string
e error
S string
}
type errorer struct{}
func (e errorer) Error() string { return "errorer" }
type unexportedCustomError struct {
e errorer
}
type errorInterface interface {
error
ExtraMethod()
}
type unexportedErrorInterface struct {
e errorInterface
}
func UnexportedStringerOrError() {
fmt.Printf("%s", unexportedInterface{"foo"}) // ok; prints {foo}
fmt.Printf("%s", unexportedInterface{3}) // ok; we can't see the problem
us := unexportedStringer{}
fmt.Printf("%s", us) // ERROR "Printf format %s has arg us of wrong type .*print.unexportedStringer"
fmt.Printf("%s", &us) // ERROR "Printf format %s has arg &us of wrong type [*].*print.unexportedStringer"
usf := unexportedStringerOtherFields{
s: "foo",
S: "bar",
}
fmt.Printf("%s", usf) // ERROR "Printf format %s has arg usf of wrong type .*print.unexportedStringerOtherFields"
fmt.Printf("%s", &usf) // ERROR "Printf format %s has arg &usf of wrong type [*].*print.unexportedStringerOtherFields"
ue := unexportedError{
e: &errorer{},
}
fmt.Printf("%s", ue) // ERROR "Printf format %s has arg ue of wrong type .*print.unexportedError"
fmt.Printf("%s", &ue) // ERROR "Printf format %s has arg &ue of wrong type [*].*print.unexportedError"
uef := unexportedErrorOtherFields{
s: "foo",
e: &errorer{},
S: "bar",
}
fmt.Printf("%s", uef) // ERROR "Printf format %s has arg uef of wrong type .*print.unexportedErrorOtherFields"
fmt.Printf("%s", &uef) // ERROR "Printf format %s has arg &uef of wrong type [*].*print.unexportedErrorOtherFields"
uce := unexportedCustomError{
e: errorer{},
}
fmt.Printf("%s", uce) // ERROR "Printf format %s has arg uce of wrong type .*print.unexportedCustomError"
uei := unexportedErrorInterface{}
fmt.Printf("%s", uei) // ERROR "Printf format %s has arg uei of wrong type .*print.unexportedErrorInterface"
fmt.Println("foo\n", "bar") // not an error
fmt.Println("foo\n") // ERROR "Println arg list ends with redundant newline"
fmt.Println("foo\\n") // not an error
fmt.Println(`foo\n`) // not an error
intSlice := []int{3, 4}
fmt.Printf("%s", intSlice) // ERROR "Printf format %s has arg intSlice of wrong type \[\]int"
nonStringerArray := [1]unexportedStringer{{}}
fmt.Printf("%s", nonStringerArray) // ERROR "Printf format %s has arg nonStringerArray of wrong type \[1\].*print.unexportedStringer"
fmt.Printf("%s", []stringer{3, 4}) // not an error
fmt.Printf("%s", [2]stringer{3, 4}) // not an error
}
// TODO: Disable complaint about '0' for Go 1.10. To be fixed properly in 1.11.
// See issues 23598 and 23605.
func DisableErrorForFlag0() {
fmt.Printf("%0t", true)
}
// Issue 26486.
func dbg(format string, args ...interface{}) {
if format == "" {
format = "%v"
}
fmt.Printf(format, args...)
}
func PointersToCompoundTypes() {
stringSlice := []string{"a", "b"}
fmt.Printf("%s", &stringSlice) // not an error
intSlice := []int{3, 4}
fmt.Printf("%s", &intSlice) // ERROR "Printf format %s has arg &intSlice of wrong type \*\[\]int"
stringArray := [2]string{"a", "b"}
fmt.Printf("%s", &stringArray) // not an error
intArray := [2]int{3, 4}
fmt.Printf("%s", &intArray) // ERROR "Printf format %s has arg &intArray of wrong type \*\[2\]int"
stringStruct := struct{ F string }{"foo"}
fmt.Printf("%s", &stringStruct) // not an error
intStruct := struct{ F int }{3}
fmt.Printf("%s", &intStruct) // ERROR "Printf format %s has arg &intStruct of wrong type \*struct{F int}"
stringMap := map[string]string{"foo": "bar"}
fmt.Printf("%s", &stringMap) // not an error
intMap := map[int]int{3: 4}
fmt.Printf("%s", &intMap) // ERROR "Printf format %s has arg &intMap of wrong type \*map\[int\]int"
type T2 struct {
X string
}
type T1 struct {
X *T2
}
fmt.Printf("%s\n", T1{&T2{"x"}}) // ERROR "Printf format %s has arg T1{&T2{.x.}} of wrong type .*print\.T1"
}
|
