print.go

Documentation: cmd/vet/testdata/print

     1  // Copyright 2010 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // This file contains tests for the printf checker.
     6  
     7  package print
     8  
     9  import (
    10  	"fmt"
    11  	logpkg "log" // renamed to make it harder to see
    12  	"math"
    13  	"os"
    14  	"testing"
    15  	"unsafe" // just for test case printing unsafe.Pointer
    16  	// For testing printf-like functions from external package.
    17  	// "github.com/foobar/externalprintf"
    18  )
    19  
    20  func UnsafePointerPrintfTest() {
    21  	var up unsafe.Pointer
    22  	fmt.Printf("%p, %x %X", up, up, up)
    23  }
    24  
    25  // Error methods that do not satisfy the Error interface and should be checked.
    26  type errorTest1 int
    27  
    28  func (errorTest1) Error(...interface{}) string {
    29  	return "hi"
    30  }
    31  
    32  type errorTest2 int // Analogous to testing's *T type.
    33  func (errorTest2) Error(...interface{}) {
    34  }
    35  
    36  type errorTest3 int
    37  
    38  func (errorTest3) Error() { // No return value.
    39  }
    40  
    41  type errorTest4 int
    42  
    43  func (errorTest4) Error() int { // Different return type.
    44  	return 3
    45  }
    46  
    47  type errorTest5 int
    48  
    49  func (errorTest5) error() { // niladic; don't complain if no args (was bug)
    50  }
    51  
    52  // This function never executes, but it serves as a simple test for the program.
    53  // Test with make test.
    54  func PrintfTests() {
    55  	var b bool
    56  	var i int
    57  	var r rune
    58  	var s string
    59  	var x float64
    60  	var p *int
    61  	var imap map[int]int
    62  	var fslice []float64
    63  	var c complex64
    64  	// Some good format/argtypes
    65  	fmt.Printf("")
    66  	fmt.Printf("%b %b %b", 3, i, x)
    67  	fmt.Printf("%c %c %c %c", 3, i, 'x', r)
    68  	fmt.Printf("%d %d %d", 3, i, imap)
    69  	fmt.Printf("%e %e %e %e", 3e9, x, fslice, c)
    70  	fmt.Printf("%E %E %E %E", 3e9, x, fslice, c)
    71  	fmt.Printf("%f %f %f %f", 3e9, x, fslice, c)
    72  	fmt.Printf("%F %F %F %F", 3e9, x, fslice, c)
    73  	fmt.Printf("%g %g %g %g", 3e9, x, fslice, c)
    74  	fmt.Printf("%G %G %G %G", 3e9, x, fslice, c)
    75  	fmt.Printf("%b %b %b %b", 3e9, x, fslice, c)
    76  	fmt.Printf("%o %o", 3, i)
    77  	fmt.Printf("%p", p)
    78  	fmt.Printf("%q %q %q %q", 3, i, 'x', r)
    79  	fmt.Printf("%s %s %s", "hi", s, []byte{65})
    80  	fmt.Printf("%t %t", true, b)
    81  	fmt.Printf("%T %T", 3, i)
    82  	fmt.Printf("%U %U", 3, i)
    83  	fmt.Printf("%v %v", 3, i)
    84  	fmt.Printf("%x %x %x %x %x %x %x", 3, i, "hi", s, x, c, fslice)
    85  	fmt.Printf("%X %X %X %X %X %X %X", 3, i, "hi", s, x, c, fslice)
    86  	fmt.Printf("%.*s %d %g", 3, "hi", 23, 2.3)
    87  	fmt.Printf("%s", &stringerv)
    88  	fmt.Printf("%v", &stringerv)
    89  	fmt.Printf("%T", &stringerv)
    90  	fmt.Printf("%s", &embeddedStringerv)
    91  	fmt.Printf("%v", &embeddedStringerv)
    92  	fmt.Printf("%T", &embeddedStringerv)
    93  	fmt.Printf("%v", notstringerv)
    94  	fmt.Printf("%T", notstringerv)
    95  	fmt.Printf("%q", stringerarrayv)
    96  	fmt.Printf("%v", stringerarrayv)
    97  	fmt.Printf("%s", stringerarrayv)
    98  	fmt.Printf("%v", notstringerarrayv)
    99  	fmt.Printf("%T", notstringerarrayv)
   100  	fmt.Printf("%d", new(fmt.Formatter))
   101  	fmt.Printf("%*%", 2)               // Ridiculous but allowed.
   102  	fmt.Printf("%s", interface{}(nil)) // Nothing useful we can say.
   103  
   104  	fmt.Printf("%g", 1+2i)
   105  	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
   106  	// Some bad format/argTypes
   107  	fmt.Printf("%b", "hi")                      // ERROR "Printf format %b has arg \x22hi\x22 of wrong type string"
   108  	fmt.Printf("%t", c)                         // ERROR "Printf format %t has arg c of wrong type complex64"
   109  	fmt.Printf("%t", 1+2i)                      // ERROR "Printf format %t has arg 1 \+ 2i of wrong type complex128"
   110  	fmt.Printf("%c", 2.3)                       // ERROR "Printf format %c has arg 2.3 of wrong type float64"
   111  	fmt.Printf("%d", 2.3)                       // ERROR "Printf format %d has arg 2.3 of wrong type float64"
   112  	fmt.Printf("%e", "hi")                      // ERROR "Printf format %e has arg \x22hi\x22 of wrong type string"
   113  	fmt.Printf("%E", true)                      // ERROR "Printf format %E has arg true of wrong type bool"
   114  	fmt.Printf("%f", "hi")                      // ERROR "Printf format %f has arg \x22hi\x22 of wrong type string"
   115  	fmt.Printf("%F", 'x')                       // ERROR "Printf format %F has arg 'x' of wrong type rune"
   116  	fmt.Printf("%g", "hi")                      // ERROR "Printf format %g has arg \x22hi\x22 of wrong type string"
   117  	fmt.Printf("%g", imap)                      // ERROR "Printf format %g has arg imap of wrong type map\[int\]int"
   118  	fmt.Printf("%G", i)                         // ERROR "Printf format %G has arg i of wrong type int"
   119  	fmt.Printf("%o", x)                         // ERROR "Printf format %o has arg x of wrong type float64"
   120  	fmt.Printf("%p", nil)                       // ERROR "Printf format %p has arg nil of wrong type untyped nil"
   121  	fmt.Printf("%p", 23)                        // ERROR "Printf format %p has arg 23 of wrong type int"
   122  	fmt.Printf("%q", x)                         // ERROR "Printf format %q has arg x of wrong type float64"
   123  	fmt.Printf("%s", b)                         // ERROR "Printf format %s has arg b of wrong type bool"
   124  	fmt.Printf("%s", byte(65))                  // ERROR "Printf format %s has arg byte\(65\) of wrong type byte"
   125  	fmt.Printf("%t", 23)                        // ERROR "Printf format %t has arg 23 of wrong type int"
   126  	fmt.Printf("%U", x)                         // ERROR "Printf format %U has arg x of wrong type float64"
   127  	fmt.Printf("%x", nil)                       // ERROR "Printf format %x has arg nil of wrong type untyped nil"
   128  	fmt.Printf("%s", stringerv)                 // ERROR "Printf format %s has arg stringerv of wrong type .*print.ptrStringer"
   129  	fmt.Printf("%t", stringerv)                 // ERROR "Printf format %t has arg stringerv of wrong type .*print.ptrStringer"
   130  	fmt.Printf("%s", embeddedStringerv)         // ERROR "Printf format %s has arg embeddedStringerv of wrong type .*print.embeddedStringer"
   131  	fmt.Printf("%t", embeddedStringerv)         // ERROR "Printf format %t has arg embeddedStringerv of wrong type .*print.embeddedStringer"
   132  	fmt.Printf("%q", notstringerv)              // ERROR "Printf format %q has arg notstringerv of wrong type .*print.notstringer"
   133  	fmt.Printf("%t", notstringerv)              // ERROR "Printf format %t has arg notstringerv of wrong type .*print.notstringer"
   134  	fmt.Printf("%t", stringerarrayv)            // ERROR "Printf format %t has arg stringerarrayv of wrong type .*print.stringerarray"
   135  	fmt.Printf("%t", notstringerarrayv)         // ERROR "Printf format %t has arg notstringerarrayv of wrong type .*print.notstringerarray"
   136  	fmt.Printf("%q", notstringerarrayv)         // ERROR "Printf format %q has arg notstringerarrayv of wrong type .*print.notstringerarray"
   137  	fmt.Printf("%d", BoolFormatter(true))       // ERROR "Printf format %d has arg BoolFormatter\(true\) of wrong type .*print.BoolFormatter"
   138  	fmt.Printf("%z", FormatterVal(true))        // correct (the type is responsible for formatting)
   139  	fmt.Printf("%d", FormatterVal(true))        // correct (the type is responsible for formatting)
   140  	fmt.Printf("%s", nonemptyinterface)         // correct (the type is responsible for formatting)
   141  	fmt.Printf("%.*s %d %6g", 3, "hi", 23, 'x') // ERROR "Printf format %6g has arg 'x' of wrong type rune"
   142  	fmt.Println()                               // not an error
   143  	fmt.Println("%s", "hi")                     // ERROR "Println call has possible formatting directive %s"
   144  	fmt.Println("%v", "hi")                     // ERROR "Println call has possible formatting directive %v"
   145  	fmt.Println("%T", "hi")                     // ERROR "Println call has possible formatting directive %T"
   146  	fmt.Println("0.0%")                         // correct (trailing % couldn't be a formatting directive)
   147  	fmt.Printf("%s", "hi", 3)                   // ERROR "Printf call needs 1 arg but has 2 args"
   148  	_ = fmt.Sprintf("%"+("s"), "hi", 3)         // ERROR "Sprintf call needs 1 arg but has 2 args"
   149  	fmt.Printf("%s%%%d", "hi", 3)               // correct
   150  	fmt.Printf("%08s", "woo")                   // correct
   151  	fmt.Printf("% 8s", "woo")                   // correct
   152  	fmt.Printf("%.*d", 3, 3)                    // correct
   153  	fmt.Printf("%.*d x", 3, 3, 3, 3)            // ERROR "Printf call needs 2 args but has 4 args"
   154  	fmt.Printf("%.*d x", "hi", 3)               // ERROR "Printf format %.*d uses non-int \x22hi\x22 as argument of \*"
   155  	fmt.Printf("%.*d x", i, 3)                  // correct
   156  	fmt.Printf("%.*d x", s, 3)                  // ERROR "Printf format %.\*d uses non-int s as argument of \*"
   157  	fmt.Printf("%*% x", 0.22)                   // ERROR "Printf format %\*% uses non-int 0.22 as argument of \*"
   158  	fmt.Printf("%q %q", multi()...)             // ok
   159  	fmt.Printf("%#q", `blah`)                   // ok
   160  	// printf("now is the time", "buddy")          // no error "printf call has arguments but no formatting directives"
   161  	Printf("now is the time", "buddy") // ERROR "Printf call has arguments but no formatting directives"
   162  	Printf("hi")                       // ok
   163  	const format = "%s %s\n"
   164  	Printf(format, "hi", "there")
   165  	Printf(format, "hi")              // ERROR "Printf format %s reads arg #2, but call has 1 arg$"
   166  	Printf("%s %d %.3v %q", "str", 4) // ERROR "Printf format %.3v reads arg #3, but call has 2 args"
   167  	f := new(ptrStringer)
   168  	f.Warn(0, "%s", "hello", 3)           // ERROR "Warn call has possible formatting directive %s"
   169  	f.Warnf(0, "%s", "hello", 3)          // ERROR "Warnf call needs 1 arg but has 2 args"
   170  	f.Warnf(0, "%r", "hello")             // ERROR "Warnf format %r has unknown verb r"
   171  	f.Warnf(0, "%#s", "hello")            // ERROR "Warnf format %#s has unrecognized flag #"
   172  	f.Warn2(0, "%s", "hello", 3)          // ERROR "Warn2 call has possible formatting directive %s"
   173  	f.Warnf2(0, "%s", "hello", 3)         // ERROR "Warnf2 call needs 1 arg but has 2 args"
   174  	f.Warnf2(0, "%r", "hello")            // ERROR "Warnf2 format %r has unknown verb r"
   175  	f.Warnf2(0, "%#s", "hello")           // ERROR "Warnf2 format %#s has unrecognized flag #"
   176  	f.Wrap(0, "%s", "hello", 3)           // ERROR "Wrap call has possible formatting directive %s"
   177  	f.Wrapf(0, "%s", "hello", 3)          // ERROR "Wrapf call needs 1 arg but has 2 args"
   178  	f.Wrapf(0, "%r", "hello")             // ERROR "Wrapf format %r has unknown verb r"
   179  	f.Wrapf(0, "%#s", "hello")            // ERROR "Wrapf format %#s has unrecognized flag #"
   180  	f.Wrap2(0, "%s", "hello", 3)          // ERROR "Wrap2 call has possible formatting directive %s"
   181  	f.Wrapf2(0, "%s", "hello", 3)         // ERROR "Wrapf2 call needs 1 arg but has 2 args"
   182  	f.Wrapf2(0, "%r", "hello")            // ERROR "Wrapf2 format %r has unknown verb r"
   183  	f.Wrapf2(0, "%#s", "hello")           // ERROR "Wrapf2 format %#s has unrecognized flag #"
   184  	fmt.Printf("%#s", FormatterVal(true)) // correct (the type is responsible for formatting)
   185  	Printf("d%", 2)                       // ERROR "Printf format % is missing verb at end of string"
   186  	Printf("%d", percentDV)
   187  	Printf("%d", &percentDV)
   188  	Printf("%d", notPercentDV)  // ERROR "Printf format %d has arg notPercentDV of wrong type .*print.notPercentDStruct"
   189  	Printf("%d", &notPercentDV) // ERROR "Printf format %d has arg &notPercentDV of wrong type \*.*print.notPercentDStruct"
   190  	Printf("%p", &notPercentDV) // Works regardless: we print it as a pointer.
   191  	Printf("%q", &percentDV)    // ERROR "Printf format %q has arg &percentDV of wrong type \*.*print.percentDStruct"
   192  	Printf("%s", percentSV)
   193  	Printf("%s", &percentSV)
   194  	// Good argument reorderings.
   195  	Printf("%[1]d", 3)
   196  	Printf("%[1]*d", 3, 1)
   197  	Printf("%[2]*[1]d", 1, 3)
   198  	Printf("%[2]*.[1]*[3]d", 2, 3, 4)
   199  	fmt.Fprintf(os.Stderr, "%[2]*.[1]*[3]d", 2, 3, 4) // Use Fprintf to make sure we count arguments correctly.
   200  	// Bad argument reorderings.
   201  	Printf("%[xd", 3)                      // ERROR "Printf format %\[xd is missing closing \]"
   202  	Printf("%[x]d x", 3)                   // ERROR "Printf format has invalid argument index \[x\]"
   203  	Printf("%[3]*s x", "hi", 2)            // ERROR "Printf format has invalid argument index \[3\]"
   204  	_ = fmt.Sprintf("%[3]d x", 2)          // ERROR "Sprintf format has invalid argument index \[3\]"
   205  	Printf("%[2]*.[1]*[3]d x", 2, "hi", 4) // ERROR "Printf format %\[2]\*\.\[1\]\*\[3\]d uses non-int \x22hi\x22 as argument of \*"
   206  	Printf("%[0]s x", "arg1")              // ERROR "Printf format has invalid argument index \[0\]"
   207  	Printf("%[0]d x", 1)                   // ERROR "Printf format has invalid argument index \[0\]"
   208  	// Something that satisfies the error interface.
   209  	var e error
   210  	fmt.Println(e.Error()) // ok
   211  	// Something that looks like an error interface but isn't, such as the (*T).Error method
   212  	// in the testing package.
   213  	var et1 *testing.T
   214  	et1.Error()        // ok
   215  	et1.Error("hi")    // ok
   216  	et1.Error("%d", 3) // ERROR "Error call has possible formatting directive %d"
   217  	var et3 errorTest3
   218  	et3.Error() // ok, not an error method.
   219  	var et4 errorTest4
   220  	et4.Error() // ok, not an error method.
   221  	var et5 errorTest5
   222  	et5.error() // ok, not an error method.
   223  	// Interfaces can be used with any verb.
   224  	var iface interface {
   225  		ToTheMadness() bool // Method ToTheMadness usually returns false
   226  	}
   227  	fmt.Printf("%f", iface) // ok: fmt treats interfaces as transparent and iface may well have a float concrete type
   228  	// Can't print a function.
   229  	Printf("%d", someFunction) // ERROR "Printf format %d arg someFunction is a func value, not called"
   230  	Printf("%v", someFunction) // ERROR "Printf format %v arg someFunction is a func value, not called"
   231  	Println(someFunction)      // ERROR "Println arg someFunction is a func value, not called"
   232  	Printf("%p", someFunction) // ok: maybe someone wants to see the pointer
   233  	Printf("%T", someFunction) // ok: maybe someone wants to see the type
   234  	// Bug: used to recur forever.
   235  	Printf("%p %x", recursiveStructV, recursiveStructV.next)
   236  	Printf("%p %x", recursiveStruct1V, recursiveStruct1V.next) // ERROR "Printf format %x has arg recursiveStruct1V\.next of wrong type \*.*print\.RecursiveStruct2"
   237  	Printf("%p %x", recursiveSliceV, recursiveSliceV)
   238  	Printf("%p %x", recursiveMapV, recursiveMapV)
   239  	// Special handling for Log.
   240  	math.Log(3) // OK
   241  	var t *testing.T
   242  	t.Log("%d", 3) // ERROR "Log call has possible formatting directive %d"
   243  	t.Logf("%d", 3)
   244  	t.Logf("%d", "hi") // ERROR "Logf format %d has arg \x22hi\x22 of wrong type string"
   245  
   246  	Errorf(1, "%d", 3)    // OK
   247  	Errorf(1, "%d", "hi") // ERROR "Errorf format %d has arg \x22hi\x22 of wrong type string"
   248  
   249  	// Multiple string arguments before variadic args
   250  	errorf("WARNING", "foobar")            // OK
   251  	errorf("INFO", "s=%s, n=%d", "foo", 1) // OK
   252  	errorf("ERROR", "%d")                  // ERROR "errorf format %d reads arg #1, but call has 0 args"
   253  
   254  	// Printf from external package
   255  	// externalprintf.Printf("%d", 42) // OK
   256  	// externalprintf.Printf("foobar") // OK
   257  	// level := 123
   258  	// externalprintf.Logf(level, "%d", 42)                        // OK
   259  	// externalprintf.Errorf(level, level, "foo %q bar", "foobar") // OK
   260  	// externalprintf.Logf(level, "%d")                            // no error "Logf format %d reads arg #1, but call has 0 args"
   261  	// var formatStr = "%s %s"
   262  	// externalprintf.Sprintf(formatStr, "a", "b")     // OK
   263  	// externalprintf.Logf(level, formatStr, "a", "b") // OK
   264  
   265  	// user-defined Println-like functions
   266  	ss := &someStruct{}
   267  	ss.Log(someFunction, "foo")          // OK
   268  	ss.Error(someFunction, someFunction) // OK
   269  	ss.Println()                         // OK
   270  	ss.Println(1.234, "foo")             // OK
   271  	ss.Println(1, someFunction)          // no error "Println arg someFunction is a func value, not called"
   272  	ss.log(someFunction)                 // OK
   273  	ss.log(someFunction, "bar", 1.33)    // OK
   274  	ss.log(someFunction, someFunction)   // no error "log arg someFunction is a func value, not called"
   275  
   276  	// indexed arguments
   277  	Printf("%d %[3]d %d %[2]d x", 1, 2, 3, 4)             // OK
   278  	Printf("%d %[0]d %d %[2]d x", 1, 2, 3, 4)             // ERROR "Printf format has invalid argument index \[0\]"
   279  	Printf("%d %[3]d %d %[-2]d x", 1, 2, 3, 4)            // ERROR "Printf format has invalid argument index \[-2\]"
   280  	Printf("%d %[3]d %d %[2234234234234]d x", 1, 2, 3, 4) // ERROR "Printf format has invalid argument index \[2234234234234\]"
   281  	Printf("%d %[3]d %-10d %[2]d x", 1, 2, 3)             // ERROR "Printf format %-10d reads arg #4, but call has 3 args"
   282  	Printf("%[1][3]d x", 1, 2)                            // ERROR "Printf format %\[1\]\[ has unknown verb \["
   283  	Printf("%[1]d x", 1, 2)                               // OK
   284  	Printf("%d %[3]d %d %[2]d x", 1, 2, 3, 4, 5)          // OK
   285  
   286  	// wrote Println but meant Fprintln
   287  	Printf("%p\n", os.Stdout)   // OK
   288  	Println(os.Stdout, "hello") // ERROR "Println does not take io.Writer but has first arg os.Stdout"
   289  
   290  	Printf(someString(), "hello") // OK
   291  
   292  	// Printf wrappers in package log should be detected automatically
   293  	logpkg.Fatal("%d", 1)    // ERROR "Fatal call has possible formatting directive %d"
   294  	logpkg.Fatalf("%d", "x") // ERROR "Fatalf format %d has arg \x22x\x22 of wrong type string"
   295  	logpkg.Fatalln("%d", 1)  // ERROR "Fatalln call has possible formatting directive %d"
   296  	logpkg.Panic("%d", 1)    // ERROR "Panic call has possible formatting directive %d"
   297  	logpkg.Panicf("%d", "x") // ERROR "Panicf format %d has arg \x22x\x22 of wrong type string"
   298  	logpkg.Panicln("%d", 1)  // ERROR "Panicln call has possible formatting directive %d"
   299  	logpkg.Print("%d", 1)    // ERROR "Print call has possible formatting directive %d"
   300  	logpkg.Printf("%d", "x") // ERROR "Printf format %d has arg \x22x\x22 of wrong type string"
   301  	logpkg.Println("%d", 1)  // ERROR "Println call has possible formatting directive %d"
   302  
   303  	// Methods too.
   304  	var l *logpkg.Logger
   305  	l.Fatal("%d", 1)    // ERROR "Fatal call has possible formatting directive %d"
   306  	l.Fatalf("%d", "x") // ERROR "Fatalf format %d has arg \x22x\x22 of wrong type string"
   307  	l.Fatalln("%d", 1)  // ERROR "Fatalln call has possible formatting directive %d"
   308  	l.Panic("%d", 1)    // ERROR "Panic call has possible formatting directive %d"
   309  	l.Panicf("%d", "x") // ERROR "Panicf format %d has arg \x22x\x22 of wrong type string"
   310  	l.Panicln("%d", 1)  // ERROR "Panicln call has possible formatting directive %d"
   311  	l.Print("%d", 1)    // ERROR "Print call has possible formatting directive %d"
   312  	l.Printf("%d", "x") // ERROR "Printf format %d has arg \x22x\x22 of wrong type string"
   313  	l.Println("%d", 1)  // ERROR "Println call has possible formatting directive %d"
   314  
   315  	// Issue 26486
   316  	dbg("", 1) // no error "call has arguments but no formatting directive"
   317  }
   318  
   319  func someString() string { return "X" }
   320  
   321  type someStruct struct{}
   322  
   323  // Log is non-variadic user-define Println-like function.
   324  // Calls to this func must be skipped when checking
   325  // for Println-like arguments.
   326  func (ss *someStruct) Log(f func(), s string) {}
   327  
   328  // Error is variadic user-define Println-like function.
   329  // Calls to this func mustn't be checked for Println-like arguments,
   330  // since variadic arguments type isn't interface{}.
   331  func (ss *someStruct) Error(args ...func()) {}
   332  
   333  // Println is variadic user-defined Println-like function.
   334  // Calls to this func must be checked for Println-like arguments.
   335  func (ss *someStruct) Println(args ...interface{}) {}
   336  
   337  // log is variadic user-defined Println-like function.
   338  // Calls to this func must be checked for Println-like arguments.
   339  func (ss *someStruct) log(f func(), args ...interface{}) {}
   340  
   341  // A function we use as a function value; it has no other purpose.
   342  func someFunction() {}
   343  
   344  // Printf is used by the test so we must declare it.
   345  func Printf(format string, args ...interface{}) {
   346  	fmt.Printf(format, args...)
   347  }
   348  
   349  // Println is used by the test so we must declare it.
   350  func Println(args ...interface{}) {
   351  	fmt.Println(args...)
   352  }
   353  
   354  // printf is used by the test so we must declare it.
   355  func printf(format string, args ...interface{}) {
   356  	fmt.Printf(format, args...)
   357  }
   358  
   359  // Errorf is used by the test for a case in which the first parameter
   360  // is not a format string.
   361  func Errorf(i int, format string, args ...interface{}) {
   362  	_ = fmt.Errorf(format, args...)
   363  }
   364  
   365  // errorf is used by the test for a case in which the function accepts multiple
   366  // string parameters before variadic arguments
   367  func errorf(level, format string, args ...interface{}) {
   368  	_ = fmt.Errorf(format, args...)
   369  }
   370  
   371  // multi is used by the test.
   372  func multi() []interface{} {
   373  	panic("don't call - testing only")
   374  }
   375  
   376  type stringer int
   377  
   378  func (stringer) String() string { return "string" }
   379  
   380  type ptrStringer float64
   381  
   382  var stringerv ptrStringer
   383  
   384  func (*ptrStringer) String() string {
   385  	return "string"
   386  }
   387  
   388  func (p *ptrStringer) Warn2(x int, args ...interface{}) string {
   389  	return p.Warn(x, args...)
   390  }
   391  
   392  func (p *ptrStringer) Warnf2(x int, format string, args ...interface{}) string {
   393  	return p.Warnf(x, format, args...)
   394  }
   395  
   396  func (*ptrStringer) Warn(x int, args ...interface{}) string {
   397  	return "warn"
   398  }
   399  
   400  func (*ptrStringer) Warnf(x int, format string, args ...interface{}) string {
   401  	return "warnf"
   402  }
   403  
   404  func (p *ptrStringer) Wrap2(x int, args ...interface{}) string {
   405  	return p.Wrap(x, args...)
   406  }
   407  
   408  func (p *ptrStringer) Wrapf2(x int, format string, args ...interface{}) string {
   409  	return p.Wrapf(x, format, args...)
   410  }
   411  
   412  func (*ptrStringer) Wrap(x int, args ...interface{}) string {
   413  	return fmt.Sprint(args...)
   414  }
   415  
   416  func (*ptrStringer) Wrapf(x int, format string, args ...interface{}) string {
   417  	return fmt.Sprintf(format, args...)
   418  }
   419  
   420  func (*ptrStringer) BadWrap(x int, args ...interface{}) string {
   421  	return fmt.Sprint(args) // ERROR "missing ... in args forwarded to print-like function"
   422  }
   423  
   424  func (*ptrStringer) BadWrapf(x int, format string, args ...interface{}) string {
   425  	return fmt.Sprintf(format, args) // ERROR "missing ... in args forwarded to printf-like function"
   426  }
   427  
   428  func (*ptrStringer) WrapfFalsePositive(x int, arg1 string, arg2 ...interface{}) string {
   429  	return fmt.Sprintf("%s %v", arg1, arg2)
   430  }
   431  
   432  type embeddedStringer struct {
   433  	foo string
   434  	ptrStringer
   435  	bar int
   436  }
   437  
   438  var embeddedStringerv embeddedStringer
   439  
   440  type notstringer struct {
   441  	f float64
   442  }
   443  
   444  var notstringerv notstringer
   445  
   446  type stringerarray [4]float64
   447  
   448  func (stringerarray) String() string {
   449  	return "string"
   450  }
   451  
   452  var stringerarrayv stringerarray
   453  
   454  type notstringerarray [4]float64
   455  
   456  var notstringerarrayv notstringerarray
   457  
   458  var nonemptyinterface = interface {
   459  	f()
   460  }(nil)
   461  
   462  // A data type we can print with "%d".
   463  type percentDStruct struct {
   464  	a int
   465  	b []byte
   466  	c *float64
   467  }
   468  
   469  var percentDV percentDStruct
   470  
   471  // A data type we cannot print correctly with "%d".
   472  type notPercentDStruct struct {
   473  	a int
   474  	b []byte
   475  	c bool
   476  }
   477  
   478  var notPercentDV notPercentDStruct
   479  
   480  // A data type we can print with "%s".
   481  type percentSStruct struct {
   482  	a string
   483  	b []byte
   484  	C stringerarray
   485  }
   486  
   487  var percentSV percentSStruct
   488  
   489  type recursiveStringer int
   490  
   491  func (s recursiveStringer) String() string {
   492  	_ = fmt.Sprintf("%d", s)
   493  	_ = fmt.Sprintf("%#v", s)
   494  	_ = fmt.Sprintf("%v", s)  // ERROR "Sprintf format %v with arg s causes recursive String method call"
   495  	_ = fmt.Sprintf("%v", &s) // ERROR "Sprintf format %v with arg &s causes recursive String method call"
   496  	_ = fmt.Sprintf("%T", s)  // ok; does not recursively call String
   497  	return fmt.Sprintln(s)    // ERROR "Sprintln arg s causes recursive call to String method"
   498  }
   499  
   500  type recursivePtrStringer int
   501  
   502  func (p *recursivePtrStringer) String() string {
   503  	_ = fmt.Sprintf("%v", *p)
   504  	_ = fmt.Sprint(&p)     // ok; prints address
   505  	return fmt.Sprintln(p) // ERROR "Sprintln arg p causes recursive call to String method"
   506  }
   507  
   508  type BoolFormatter bool
   509  
   510  func (*BoolFormatter) Format(fmt.State, rune) {
   511  }
   512  
   513  // Formatter with value receiver
   514  type FormatterVal bool
   515  
   516  func (FormatterVal) Format(fmt.State, rune) {
   517  }
   518  
   519  type RecursiveSlice []RecursiveSlice
   520  
   521  var recursiveSliceV = &RecursiveSlice{}
   522  
   523  type RecursiveMap map[int]RecursiveMap
   524  
   525  var recursiveMapV = make(RecursiveMap)
   526  
   527  type RecursiveStruct struct {
   528  	next *RecursiveStruct
   529  }
   530  
   531  var recursiveStructV = &RecursiveStruct{}
   532  
   533  type RecursiveStruct1 struct {
   534  	next *RecursiveStruct2
   535  }
   536  
   537  type RecursiveStruct2 struct {
   538  	next *RecursiveStruct1
   539  }
   540  
   541  var recursiveStruct1V = &RecursiveStruct1{}
   542  
   543  type unexportedInterface struct {
   544  	f interface{}
   545  }
   546  
   547  // Issue 17798: unexported ptrStringer cannot be formatted.
   548  type unexportedStringer struct {
   549  	t ptrStringer
   550  }
   551  type unexportedStringerOtherFields struct {
   552  	s string
   553  	t ptrStringer
   554  	S string
   555  }
   556  
   557  // Issue 17798: unexported error cannot be formatted.
   558  type unexportedError struct {
   559  	e error
   560  }
   561  type unexportedErrorOtherFields struct {
   562  	s string
   563  	e error
   564  	S string
   565  }
   566  
   567  type errorer struct{}
   568  
   569  func (e errorer) Error() string { return "errorer" }
   570  
   571  type unexportedCustomError struct {
   572  	e errorer
   573  }
   574  
   575  type errorInterface interface {
   576  	error
   577  	ExtraMethod()
   578  }
   579  
   580  type unexportedErrorInterface struct {
   581  	e errorInterface
   582  }
   583  
   584  func UnexportedStringerOrError() {
   585  	fmt.Printf("%s", unexportedInterface{"foo"}) // ok; prints {foo}
   586  	fmt.Printf("%s", unexportedInterface{3})     // ok; we can't see the problem
   587  
   588  	us := unexportedStringer{}
   589  	fmt.Printf("%s", us)  // ERROR "Printf format %s has arg us of wrong type .*print.unexportedStringer"
   590  	fmt.Printf("%s", &us) // ERROR "Printf format %s has arg &us of wrong type [*].*print.unexportedStringer"
   591  
   592  	usf := unexportedStringerOtherFields{
   593  		s: "foo",
   594  		S: "bar",
   595  	}
   596  	fmt.Printf("%s", usf)  // ERROR "Printf format %s has arg usf of wrong type .*print.unexportedStringerOtherFields"
   597  	fmt.Printf("%s", &usf) // ERROR "Printf format %s has arg &usf of wrong type [*].*print.unexportedStringerOtherFields"
   598  
   599  	ue := unexportedError{
   600  		e: &errorer{},
   601  	}
   602  	fmt.Printf("%s", ue)  // ERROR "Printf format %s has arg ue of wrong type .*print.unexportedError"
   603  	fmt.Printf("%s", &ue) // ERROR "Printf format %s has arg &ue of wrong type [*].*print.unexportedError"
   604  
   605  	uef := unexportedErrorOtherFields{
   606  		s: "foo",
   607  		e: &errorer{},
   608  		S: "bar",
   609  	}
   610  	fmt.Printf("%s", uef)  // ERROR "Printf format %s has arg uef of wrong type .*print.unexportedErrorOtherFields"
   611  	fmt.Printf("%s", &uef) // ERROR "Printf format %s has arg &uef of wrong type [*].*print.unexportedErrorOtherFields"
   612  
   613  	uce := unexportedCustomError{
   614  		e: errorer{},
   615  	}
   616  	fmt.Printf("%s", uce) // ERROR "Printf format %s has arg uce of wrong type .*print.unexportedCustomError"
   617  
   618  	uei := unexportedErrorInterface{}
   619  	fmt.Printf("%s", uei)       // ERROR "Printf format %s has arg uei of wrong type .*print.unexportedErrorInterface"
   620  	fmt.Println("foo\n", "bar") // not an error
   621  
   622  	fmt.Println("foo\n")  // ERROR "Println arg list ends with redundant newline"
   623  	fmt.Println("foo\\n") // not an error
   624  	fmt.Println(`foo\n`)  // not an error
   625  
   626  	intSlice := []int{3, 4}
   627  	fmt.Printf("%s", intSlice) // ERROR "Printf format %s has arg intSlice of wrong type \[\]int"
   628  	nonStringerArray := [1]unexportedStringer{{}}
   629  	fmt.Printf("%s", nonStringerArray)  // ERROR "Printf format %s has arg nonStringerArray of wrong type \[1\].*print.unexportedStringer"
   630  	fmt.Printf("%s", []stringer{3, 4})  // not an error
   631  	fmt.Printf("%s", [2]stringer{3, 4}) // not an error
   632  }
   633  
   634  // TODO: Disable complaint about '0' for Go 1.10. To be fixed properly in 1.11.
   635  // See issues 23598 and 23605.
   636  func DisableErrorForFlag0() {
   637  	fmt.Printf("%0t", true)
   638  }
   639  
   640  // Issue 26486.
   641  func dbg(format string, args ...interface{}) {
   642  	if format == "" {
   643  		format = "%v"
   644  	}
   645  	fmt.Printf(format, args...)
   646  }
   647  
   648  func PointersToCompoundTypes() {
   649  	stringSlice := []string{"a", "b"}
   650  	fmt.Printf("%s", &stringSlice) // not an error
   651  
   652  	intSlice := []int{3, 4}
   653  	fmt.Printf("%s", &intSlice) // ERROR "Printf format %s has arg &intSlice of wrong type \*\[\]int"
   654  
   655  	stringArray := [2]string{"a", "b"}
   656  	fmt.Printf("%s", &stringArray) // not an error
   657  
   658  	intArray := [2]int{3, 4}
   659  	fmt.Printf("%s", &intArray) // ERROR "Printf format %s has arg &intArray of wrong type \*\[2\]int"
   660  
   661  	stringStruct := struct{ F string }{"foo"}
   662  	fmt.Printf("%s", &stringStruct) // not an error
   663  
   664  	intStruct := struct{ F int }{3}
   665  	fmt.Printf("%s", &intStruct) // ERROR "Printf format %s has arg &intStruct of wrong type \*struct{F int}"
   666  
   667  	stringMap := map[string]string{"foo": "bar"}
   668  	fmt.Printf("%s", &stringMap) // not an error
   669  
   670  	intMap := map[int]int{3: 4}
   671  	fmt.Printf("%s", &intMap) // ERROR "Printf format %s has arg &intMap of wrong type \*map\[int\]int"
   672  
   673  	type T2 struct {
   674  		X string
   675  	}
   676  	type T1 struct {
   677  		X *T2
   678  	}
   679  	fmt.Printf("%s\n", T1{&T2{"x"}}) // ERROR "Printf format %s has arg T1{&T2{.x.}} of wrong type .*print\.T1"
   680  }
   681
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