modernc.org/gc@v1.0.1-0.20240304020402-f0dba7c97c2b/testdata/errchk/test/cmp.go (about)

     1  // run
     2  
     3  // Copyright 2009 The Go Authors. All rights reserved.
     4  // Use of this source code is governed by a BSD-style
     5  // license that can be found in the LICENSE file.
     6  
     7  // Test equality and inequality operations.
     8  
     9  package main
    10  
    11  import (
    12  	"os"
    13  	"unsafe"
    14  )
    15  
    16  var global bool
    17  
    18  func use(b bool) { global = b }
    19  
    20  func stringptr(s string) uintptr { return *(*uintptr)(unsafe.Pointer(&s)) }
    21  
    22  func isfalse(b bool) {
    23  	if b {
    24  		// stack will explain where
    25  		panic("wanted false, got true")
    26  	}
    27  }
    28  
    29  func istrue(b bool) {
    30  	if !b {
    31  		// stack will explain where
    32  		panic("wanted true, got false")
    33  	}
    34  }
    35  
    36  type T *int
    37  
    38  type X int
    39  
    40  func (X) x() {}
    41  
    42  func main() {
    43  	var a []int
    44  	var b map[string]int
    45  
    46  	var c string = "hello"
    47  	var d string = "hel" // try to get different pointer
    48  	d = d + "lo"
    49  
    50  	// go.tools/ssa/interp can't handle unsafe.Pointer.
    51  	if os.Getenv("GOSSAINTERP") == "" {
    52  		if stringptr(c) == stringptr(d) {
    53  			panic("compiler too smart -- got same string")
    54  		}
    55  	}
    56  
    57  	var e = make(chan int)
    58  
    59  	var ia interface{} = a
    60  	var ib interface{} = b
    61  	var ic interface{} = c
    62  	var id interface{} = d
    63  	var ie interface{} = e
    64  
    65  	// these comparisons are okay because
    66  	// string compare is okay and the others
    67  	// are comparisons where the types differ.
    68  	isfalse(ia == ib)
    69  	isfalse(ia == ic)
    70  	isfalse(ia == id)
    71  	isfalse(ib == ic)
    72  	isfalse(ib == id)
    73  	istrue(ic == id)
    74  	istrue(ie == ie)
    75  
    76  	istrue(ia != ib)
    77  	istrue(ia != ic)
    78  	istrue(ia != id)
    79  	istrue(ib != ic)
    80  	istrue(ib != id)
    81  	isfalse(ic != id)
    82  	isfalse(ie != ie)
    83  
    84  	// these are not okay, because there is no comparison on slices or maps.
    85  	//isfalse(a == ib)
    86  	//isfalse(a == ic)
    87  	//isfalse(a == id)
    88  	//isfalse(b == ic)
    89  	//isfalse(b == id)
    90  
    91  	istrue(c == id)
    92  	istrue(e == ie)
    93  
    94  	//isfalse(ia == b)
    95  	isfalse(ia == c)
    96  	isfalse(ia == d)
    97  	isfalse(ib == c)
    98  	isfalse(ib == d)
    99  	istrue(ic == d)
   100  	istrue(ie == e)
   101  
   102  	//istrue(a != ib)
   103  	//istrue(a != ic)
   104  	//istrue(a != id)
   105  	//istrue(b != ic)
   106  	//istrue(b != id)
   107  	isfalse(c != id)
   108  	isfalse(e != ie)
   109  
   110  	//istrue(ia != b)
   111  	istrue(ia != c)
   112  	istrue(ia != d)
   113  	istrue(ib != c)
   114  	istrue(ib != d)
   115  	isfalse(ic != d)
   116  	isfalse(ie != e)
   117  
   118  	// gc used to let this go through as true.
   119  	var g uint64 = 123
   120  	var h int64 = 123
   121  	var ig interface{} = g
   122  	var ih interface{} = h
   123  	isfalse(ig == ih)
   124  	istrue(ig != ih)
   125  
   126  	// map of interface should use == on interface values,
   127  	// not memory.
   128  	var m = make(map[interface{}]int)
   129  	m[ic] = 1
   130  	m[id] = 2
   131  	if m[c] != 2 {
   132  		println("m[c] = ", m[c])
   133  		panic("bad m[c]")
   134  	}
   135  
   136  	// interface comparisons (issue 7207)
   137  	{
   138  		type I1 interface {
   139  			x()
   140  		}
   141  		type I2 interface {
   142  			x()
   143  		}
   144  		a1 := I1(X(0))
   145  		b1 := I1(X(1))
   146  		a2 := I2(X(0))
   147  		b2 := I2(X(1))
   148  		a3 := I1(a2)
   149  		a4 := I2(a1)
   150  		var e interface{} = X(0)
   151  		a5 := e.(I1)
   152  		a6 := e.(I2)
   153  		isfalse(a1 == b1)
   154  		isfalse(a1 == b2)
   155  		isfalse(a2 == b1)
   156  		isfalse(a2 == b2)
   157  		istrue(a1 == a2)
   158  		istrue(a1 == a3)
   159  		istrue(a1 == a4)
   160  		istrue(a1 == a5)
   161  		istrue(a1 == a6)
   162  		istrue(a2 == a3)
   163  		istrue(a2 == a4)
   164  		istrue(a2 == a5)
   165  		istrue(a2 == a6)
   166  		istrue(a3 == a4)
   167  		istrue(a3 == a5)
   168  		istrue(a3 == a6)
   169  		istrue(a4 == a5)
   170  		istrue(a4 == a6)
   171  		istrue(a5 == a6)
   172  	}
   173  
   174  	// non-interface comparisons
   175  	{
   176  		c := make(chan int)
   177  		c1 := (<-chan int)(c)
   178  		c2 := (chan<- int)(c)
   179  		istrue(c == c1)
   180  		istrue(c == c2)
   181  		istrue(c1 == c)
   182  		istrue(c2 == c)
   183  
   184  		isfalse(c != c1)
   185  		isfalse(c != c2)
   186  		isfalse(c1 != c)
   187  		isfalse(c2 != c)
   188  
   189  		d := make(chan int)
   190  		isfalse(c == d)
   191  		isfalse(d == c)
   192  		isfalse(d == c1)
   193  		isfalse(d == c2)
   194  		isfalse(c1 == d)
   195  		isfalse(c2 == d)
   196  
   197  		istrue(c != d)
   198  		istrue(d != c)
   199  		istrue(d != c1)
   200  		istrue(d != c2)
   201  		istrue(c1 != d)
   202  		istrue(c2 != d)
   203  	}
   204  
   205  	// named types vs not
   206  	{
   207  		var x = new(int)
   208  		var y T
   209  		var z T = x
   210  
   211  		isfalse(x == y)
   212  		istrue(x == z)
   213  		isfalse(y == z)
   214  
   215  		isfalse(y == x)
   216  		istrue(z == x)
   217  		isfalse(z == y)
   218  
   219  		istrue(x != y)
   220  		isfalse(x != z)
   221  		istrue(y != z)
   222  
   223  		istrue(y != x)
   224  		isfalse(z != x)
   225  		istrue(z != y)
   226  	}
   227  
   228  	// structs
   229  	{
   230  		var x = struct {
   231  			x int
   232  			y string
   233  		}{1, "hi"}
   234  		var y = struct {
   235  			x int
   236  			y string
   237  		}{2, "bye"}
   238  		var z = struct {
   239  			x int
   240  			y string
   241  		}{1, "hi"}
   242  
   243  		isfalse(x == y)
   244  		isfalse(y == x)
   245  		isfalse(y == z)
   246  		isfalse(z == y)
   247  		istrue(x == z)
   248  		istrue(z == x)
   249  
   250  		istrue(x != y)
   251  		istrue(y != x)
   252  		istrue(y != z)
   253  		istrue(z != y)
   254  		isfalse(x != z)
   255  		isfalse(z != x)
   256  
   257  		var m = make(map[struct {
   258  			x int
   259  			y string
   260  		}]int)
   261  		m[x] = 10
   262  		m[y] = 20
   263  		m[z] = 30
   264  		istrue(m[x] == 30)
   265  		istrue(m[y] == 20)
   266  		istrue(m[z] == 30)
   267  		istrue(m[x] != 10)
   268  		isfalse(m[x] != 30)
   269  		isfalse(m[y] != 20)
   270  		isfalse(m[z] != 30)
   271  		isfalse(m[x] == 10)
   272  
   273  		var m1 = make(map[struct {
   274  			x int
   275  			y string
   276  		}]struct {
   277  			x int
   278  			y string
   279  		})
   280  		m1[x] = x
   281  		m1[y] = y
   282  		m1[z] = z
   283  		istrue(m1[x] == z)
   284  		istrue(m1[y] == y)
   285  		istrue(m1[z] == z)
   286  		istrue(m1[x] == x)
   287  		isfalse(m1[x] != z)
   288  		isfalse(m1[y] != y)
   289  		isfalse(m1[z] != z)
   290  		isfalse(m1[x] != x)
   291  
   292  		var ix, iy, iz interface{} = x, y, z
   293  
   294  		isfalse(ix == iy)
   295  		isfalse(iy == ix)
   296  		isfalse(iy == iz)
   297  		isfalse(iz == iy)
   298  		istrue(ix == iz)
   299  		istrue(iz == ix)
   300  
   301  		isfalse(x == iy)
   302  		isfalse(y == ix)
   303  		isfalse(y == iz)
   304  		isfalse(z == iy)
   305  		istrue(x == iz)
   306  		istrue(z == ix)
   307  
   308  		isfalse(ix == y)
   309  		isfalse(iy == x)
   310  		isfalse(iy == z)
   311  		isfalse(iz == y)
   312  		istrue(ix == z)
   313  		istrue(iz == x)
   314  
   315  		istrue(ix != iy)
   316  		istrue(iy != ix)
   317  		istrue(iy != iz)
   318  		istrue(iz != iy)
   319  		isfalse(ix != iz)
   320  		isfalse(iz != ix)
   321  
   322  		istrue(x != iy)
   323  		istrue(y != ix)
   324  		istrue(y != iz)
   325  		istrue(z != iy)
   326  		isfalse(x != iz)
   327  		isfalse(z != ix)
   328  
   329  		istrue(ix != y)
   330  		istrue(iy != x)
   331  		istrue(iy != z)
   332  		istrue(iz != y)
   333  		isfalse(ix != z)
   334  		isfalse(iz != x)
   335  	}
   336  
   337  	// structs with _ fields
   338  	{
   339  		var x = struct {
   340  			x int
   341  			_ string
   342  			y float64
   343  			_ float64
   344  			z int
   345  		}{
   346  			x: 1, y: 2, z: 3,
   347  		}
   348  		var ix interface{} = x
   349  
   350  		istrue(x == x)
   351  		istrue(x == ix)
   352  		istrue(ix == x)
   353  		istrue(ix == ix)
   354  	}
   355  
   356  	// arrays
   357  	{
   358  		var x = [2]string{"1", "hi"}
   359  		var y = [2]string{"2", "bye"}
   360  		var z = [2]string{"1", "hi"}
   361  
   362  		isfalse(x == y)
   363  		isfalse(y == x)
   364  		isfalse(y == z)
   365  		isfalse(z == y)
   366  		istrue(x == z)
   367  		istrue(z == x)
   368  
   369  		istrue(x != y)
   370  		istrue(y != x)
   371  		istrue(y != z)
   372  		istrue(z != y)
   373  		isfalse(x != z)
   374  		isfalse(z != x)
   375  
   376  		var m = make(map[[2]string]int)
   377  		m[x] = 10
   378  		m[y] = 20
   379  		m[z] = 30
   380  		istrue(m[x] == 30)
   381  		istrue(m[y] == 20)
   382  		istrue(m[z] == 30)
   383  		isfalse(m[x] != 30)
   384  		isfalse(m[y] != 20)
   385  		isfalse(m[z] != 30)
   386  
   387  		var ix, iy, iz interface{} = x, y, z
   388  
   389  		isfalse(ix == iy)
   390  		isfalse(iy == ix)
   391  		isfalse(iy == iz)
   392  		isfalse(iz == iy)
   393  		istrue(ix == iz)
   394  		istrue(iz == ix)
   395  
   396  		isfalse(x == iy)
   397  		isfalse(y == ix)
   398  		isfalse(y == iz)
   399  		isfalse(z == iy)
   400  		istrue(x == iz)
   401  		istrue(z == ix)
   402  
   403  		isfalse(ix == y)
   404  		isfalse(iy == x)
   405  		isfalse(iy == z)
   406  		isfalse(iz == y)
   407  		istrue(ix == z)
   408  		istrue(iz == x)
   409  
   410  		istrue(ix != iy)
   411  		istrue(iy != ix)
   412  		istrue(iy != iz)
   413  		istrue(iz != iy)
   414  		isfalse(ix != iz)
   415  		isfalse(iz != ix)
   416  
   417  		istrue(x != iy)
   418  		istrue(y != ix)
   419  		istrue(y != iz)
   420  		istrue(z != iy)
   421  		isfalse(x != iz)
   422  		isfalse(z != ix)
   423  
   424  		istrue(ix != y)
   425  		istrue(iy != x)
   426  		istrue(iy != z)
   427  		istrue(iz != y)
   428  		isfalse(ix != z)
   429  		isfalse(iz != x)
   430  	}
   431  
   432  	// named booleans
   433  	{
   434  		type mybool bool
   435  		var b mybool
   436  
   437  		type T struct{ data [20]byte }
   438  		var x, y T
   439  		b = x == y
   440  		istrue(x == y)
   441  		istrue(bool(b))
   442  
   443  		m := make(map[string][10]interface{})
   444  		b = m["x"] == m["y"]
   445  		istrue(m["x"] == m["y"])
   446  		istrue(bool(b))
   447  	}
   448  
   449  	shouldPanic(p1)
   450  	shouldPanic(p2)
   451  	shouldPanic(p3)
   452  	shouldPanic(p4)
   453  }
   454  
   455  func p1() {
   456  	var a []int
   457  	var ia interface{} = a
   458  	use(ia == ia)
   459  }
   460  
   461  func p2() {
   462  	var b []int
   463  	var ib interface{} = b
   464  	use(ib == ib)
   465  }
   466  
   467  func p3() {
   468  	var a []int
   469  	var ia interface{} = a
   470  	var m = make(map[interface{}]int)
   471  	m[ia] = 1
   472  }
   473  
   474  func p4() {
   475  	var b []int
   476  	var ib interface{} = b
   477  	var m = make(map[interface{}]int)
   478  	m[ib] = 1
   479  }
   480  
   481  func shouldPanic(f func()) {
   482  	defer func() {
   483  		if recover() == nil {
   484  			panic("function should panic")
   485  		}
   486  	}()
   487  	f()
   488  }