builtins_test.go

     1  // Copyright 2013 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  package types_test
     6  
     7  import (
     8  	"fmt"
     9  	"go/ast"
    10  	"testing"
    11  
    12  	. "go/types"
    13  )
    14  
    15  var builtinCalls = []struct {
    16  	name, src, sig string
    17  }{
    18  	{"append", `var s []int; _ = append(s)`, `func([]int, ...int) []int`},
    19  	{"append", `var s []int; _ = append(s, 0)`, `func([]int, ...int) []int`},
    20  	{"append", `var s []int; _ = (append)(s, 0)`, `func([]int, ...int) []int`},
    21  	{"append", `var s []byte; _ = ((append))(s, 0)`, `func([]byte, ...byte) []byte`},
    22  	{"append", `var s []byte; _ = append(s, "foo"...)`, `func([]byte, string...) []byte`},
    23  	{"append", `type T []byte; var s T; var str string; _ = append(s, str...)`, `func(p.T, string...) p.T`},
    24  	{"append", `type T []byte; type U string; var s T; var str U; _ = append(s, str...)`, `func(p.T, p.U...) p.T`},
    25  
    26  	{"cap", `var s [10]int; _ = cap(s)`, `invalid type`},  // constant
    27  	{"cap", `var s [10]int; _ = cap(&s)`, `invalid type`}, // constant
    28  	{"cap", `var s []int64; _ = cap(s)`, `func([]int64) int`},
    29  	{"cap", `var c chan<-bool; _ = cap(c)`, `func(chan<- bool) int`},
    30  	{"cap", `type S []byte; var s S; _ = cap(s)`, `func(p.S) int`},
    31  	{"cap", `var s P; _ = cap(s)`, `func(P) int`},
    32  
    33  	{"len", `_ = len("foo")`, `invalid type`}, // constant
    34  	{"len", `var s string; _ = len(s)`, `func(string) int`},
    35  	{"len", `var s [10]int; _ = len(s)`, `invalid type`},  // constant
    36  	{"len", `var s [10]int; _ = len(&s)`, `invalid type`}, // constant
    37  	{"len", `var s []int64; _ = len(s)`, `func([]int64) int`},
    38  	{"len", `var c chan<-bool; _ = len(c)`, `func(chan<- bool) int`},
    39  	{"len", `var m map[string]float32; _ = len(m)`, `func(map[string]float32) int`},
    40  	{"len", `type S []byte; var s S; _ = len(s)`, `func(p.S) int`},
    41  	{"len", `var s P; _ = len(s)`, `func(P) int`},
    42  
    43  	{"clear", `var m map[float64]int; clear(m)`, `func(map[float64]int)`},
    44  	{"clear", `var s []byte; clear(s)`, `func([]byte)`},
    45  
    46  	{"close", `var c chan int; close(c)`, `func(chan int)`},
    47  	{"close", `var c chan<- chan string; close(c)`, `func(chan<- chan string)`},
    48  
    49  	{"complex", `_ = complex(1, 0)`, `invalid type`}, // constant
    50  	{"complex", `var re float32; _ = complex(re, 1.0)`, `func(float32, float32) complex64`},
    51  	{"complex", `var im float64; _ = complex(1, im)`, `func(float64, float64) complex128`},
    52  	{"complex", `type F32 float32; var re, im F32; _ = complex(re, im)`, `func(p.F32, p.F32) complex64`},
    53  	{"complex", `type F64 float64; var re, im F64; _ = complex(re, im)`, `func(p.F64, p.F64) complex128`},
    54  
    55  	{"copy", `var src, dst []byte; copy(dst, src)`, `func([]byte, []byte) int`},
    56  	{"copy", `type T [][]int; var src, dst T; _ = copy(dst, src)`, `func(p.T, p.T) int`},
    57  	{"copy", `var src string; var dst []byte; copy(dst, src)`, `func([]byte, string) int`},
    58  	{"copy", `type T string; type U []byte; var src T; var dst U; copy(dst, src)`, `func(p.U, p.T) int`},
    59  	{"copy", `var dst []byte; copy(dst, "hello")`, `func([]byte, string) int`},
    60  
    61  	{"delete", `var m map[string]bool; delete(m, "foo")`, `func(map[string]bool, string)`},
    62  	{"delete", `type (K string; V int); var m map[K]V; delete(m, "foo")`, `func(map[p.K]p.V, p.K)`},
    63  
    64  	{"imag", `_ = imag(1i)`, `invalid type`}, // constant
    65  	{"imag", `var c complex64; _ = imag(c)`, `func(complex64) float32`},
    66  	{"imag", `var c complex128; _ = imag(c)`, `func(complex128) float64`},
    67  	{"imag", `type C64 complex64; var c C64; _ = imag(c)`, `func(p.C64) float32`},
    68  	{"imag", `type C128 complex128; var c C128; _ = imag(c)`, `func(p.C128) float64`},
    69  
    70  	{"real", `_ = real(1i)`, `invalid type`}, // constant
    71  	{"real", `var c complex64; _ = real(c)`, `func(complex64) float32`},
    72  	{"real", `var c complex128; _ = real(c)`, `func(complex128) float64`},
    73  	{"real", `type C64 complex64; var c C64; _ = real(c)`, `func(p.C64) float32`},
    74  	{"real", `type C128 complex128; var c C128; _ = real(c)`, `func(p.C128) float64`},
    75  
    76  	{"make", `_ = make([]int, 10)`, `func([]int, int) []int`},
    77  	{"make", `type T []byte; _ = make(T, 10, 20)`, `func(p.T, int, int) p.T`},
    78  
    79  	// go.dev/issue/37349
    80  	{"make", `              _ = make([]int, 0   )`, `func([]int, int) []int`},
    81  	{"make", `var l    int; _ = make([]int, l   )`, `func([]int, int) []int`},
    82  	{"make", `              _ = make([]int, 0, 0)`, `func([]int, int, int) []int`},
    83  	{"make", `var l    int; _ = make([]int, l, 0)`, `func([]int, int, int) []int`},
    84  	{"make", `var    c int; _ = make([]int, 0, c)`, `func([]int, int, int) []int`},
    85  	{"make", `var l, c int; _ = make([]int, l, c)`, `func([]int, int, int) []int`},
    86  
    87  	// go.dev/issue/37393
    88  	{"make", `                _ = make([]int       , 0   )`, `func([]int, int) []int`},
    89  	{"make", `var l    byte ; _ = make([]int8      , l   )`, `func([]int8, byte) []int8`},
    90  	{"make", `                _ = make([]int16     , 0, 0)`, `func([]int16, int, int) []int16`},
    91  	{"make", `var l    int16; _ = make([]string    , l, 0)`, `func([]string, int16, int) []string`},
    92  	{"make", `var    c int32; _ = make([]float64   , 0, c)`, `func([]float64, int, int32) []float64`},
    93  	{"make", `var l, c uint ; _ = make([]complex128, l, c)`, `func([]complex128, uint, uint) []complex128`},
    94  
    95  	// go.dev/issue/45667
    96  	{"make", `const l uint = 1; _ = make([]int, l)`, `func([]int, uint) []int`},
    97  
    98  	{"max", `               _ = max(0        )`, `invalid type`}, // constant
    99  	{"max", `var x int    ; _ = max(x        )`, `func(int) int`},
   100  	{"max", `var x int    ; _ = max(0, x     )`, `func(int, int) int`},
   101  	{"max", `var x string ; _ = max("a", x   )`, `func(string, string) string`},
   102  	{"max", `var x float32; _ = max(0, 1.0, x)`, `func(float32, float32, float32) float32`},
   103  
   104  	{"min", `               _ = min(0        )`, `invalid type`}, // constant
   105  	{"min", `var x int    ; _ = min(x        )`, `func(int) int`},
   106  	{"min", `var x int    ; _ = min(0, x     )`, `func(int, int) int`},
   107  	{"min", `var x string ; _ = min("a", x   )`, `func(string, string) string`},
   108  	{"min", `var x float32; _ = min(0, 1.0, x)`, `func(float32, float32, float32) float32`},
   109  
   110  	{"new", `_ = new(int)`, `func(int) *int`},
   111  	{"new", `type T struct{}; _ = new(T)`, `func(p.T) *p.T`},
   112  
   113  	{"panic", `panic(0)`, `func(interface{})`},
   114  	{"panic", `panic("foo")`, `func(interface{})`},
   115  
   116  	{"print", `print()`, `func()`},
   117  	{"print", `print(0)`, `func(int)`},
   118  	{"print", `print(1, 2.0, "foo", true)`, `func(int, float64, string, bool)`},
   119  
   120  	{"println", `println()`, `func()`},
   121  	{"println", `println(0)`, `func(int)`},
   122  	{"println", `println(1, 2.0, "foo", true)`, `func(int, float64, string, bool)`},
   123  
   124  	{"recover", `recover()`, `func() interface{}`},
   125  	{"recover", `_ = recover()`, `func() interface{}`},
   126  
   127  	{"Add", `var p unsafe.Pointer; _ = unsafe.Add(p, -1.0)`, `func(unsafe.Pointer, int) unsafe.Pointer`},
   128  	{"Add", `var p unsafe.Pointer; var n uintptr; _ = unsafe.Add(p, n)`, `func(unsafe.Pointer, uintptr) unsafe.Pointer`},
   129  	{"Add", `_ = unsafe.Add(nil, 0)`, `func(unsafe.Pointer, int) unsafe.Pointer`},
   130  
   131  	{"Alignof", `_ = unsafe.Alignof(0)`, `invalid type`},                 // constant
   132  	{"Alignof", `var x struct{}; _ = unsafe.Alignof(x)`, `invalid type`}, // constant
   133  	{"Alignof", `var x P; _ = unsafe.Alignof(x)`, `func(P) uintptr`},
   134  
   135  	{"Offsetof", `var x struct{f bool}; _ = unsafe.Offsetof(x.f)`, `invalid type`},           // constant
   136  	{"Offsetof", `var x struct{_ int; f bool}; _ = unsafe.Offsetof((&x).f)`, `invalid type`}, // constant
   137  	{"Offsetof", `var x struct{_ int; f P}; _ = unsafe.Offsetof((&x).f)`, `func(P) uintptr`},
   138  
   139  	{"Sizeof", `_ = unsafe.Sizeof(0)`, `invalid type`},                 // constant
   140  	{"Sizeof", `var x struct{}; _ = unsafe.Sizeof(x)`, `invalid type`}, // constant
   141  	{"Sizeof", `var x P; _ = unsafe.Sizeof(x)`, `func(P) uintptr`},
   142  
   143  	{"Slice", `var p *int; _ = unsafe.Slice(p, 1)`, `func(*int, int) []int`},
   144  	{"Slice", `var p *byte; var n uintptr; _ = unsafe.Slice(p, n)`, `func(*byte, uintptr) []byte`},
   145  	{"Slice", `type B *byte; var b B; _ = unsafe.Slice(b, 0)`, `func(*byte, int) []byte`},
   146  
   147  	{"SliceData", "var s []int; _ = unsafe.SliceData(s)", `func([]int) *int`},
   148  	{"SliceData", "type S []int; var s S; _ = unsafe.SliceData(s)", `func([]int) *int`},
   149  
   150  	{"String", `var p *byte; _ = unsafe.String(p, 1)`, `func(*byte, int) string`},
   151  	{"String", `type B *byte; var b B; _ = unsafe.String(b, 0)`, `func(*byte, int) string`},
   152  
   153  	{"StringData", `var s string; _ = unsafe.StringData(s)`, `func(string) *byte`},
   154  	{"StringData", `_ = unsafe.StringData("foo")`, `func(string) *byte`},
   155  
   156  	{"assert", `assert(true)`, `invalid type`},                                    // constant
   157  	{"assert", `type B bool; const pred B = 1 < 2; assert(pred)`, `invalid type`}, // constant
   158  
   159  	// no tests for trace since it produces output as a side-effect
   160  }
   161  
   162  func TestBuiltinSignatures(t *testing.T) {
   163  	DefPredeclaredTestFuncs()
   164  
   165  	seen := map[string]bool{"trace": true} // no test for trace built-in; add it manually
   166  	for _, call := range builtinCalls {
   167  		testBuiltinSignature(t, call.name, call.src, call.sig)
   168  		seen[call.name] = true
   169  	}
   170  
   171  	// make sure we didn't miss one
   172  	for _, name := range Universe.Names() {
   173  		if _, ok := Universe.Lookup(name).(*Builtin); ok && !seen[name] {
   174  			t.Errorf("missing test for %s", name)
   175  		}
   176  	}
   177  	for _, name := range Unsafe.Scope().Names() {
   178  		if _, ok := Unsafe.Scope().Lookup(name).(*Builtin); ok && !seen[name] {
   179  			t.Errorf("missing test for unsafe.%s", name)
   180  		}
   181  	}
   182  }
   183  
   184  func testBuiltinSignature(t *testing.T, name, src0, want string) {
   185  	src := fmt.Sprintf(`package p; import "unsafe"; type _ unsafe.Pointer /* use unsafe */; func _[P ~[]byte]() { %s }`, src0)
   186  
   187  	uses := make(map[*ast.Ident]Object)
   188  	types := make(map[ast.Expr]TypeAndValue)
   189  	mustTypecheck(src, nil, &Info{Uses: uses, Types: types})
   190  
   191  	// find called function
   192  	n := 0
   193  	var fun ast.Expr
   194  	for x := range types {
   195  		if call, _ := x.(*ast.CallExpr); call != nil {
   196  			fun = call.Fun
   197  			n++
   198  		}
   199  	}
   200  	if n != 1 {
   201  		t.Errorf("%s: got %d CallExprs; want 1", src0, n)
   202  		return
   203  	}
   204  
   205  	// check recorded types for fun and descendents (may be parenthesized)
   206  	for {
   207  		// the recorded type for the built-in must match the wanted signature
   208  		typ := types[fun].Type
   209  		if typ == nil {
   210  			t.Errorf("%s: no type recorded for %s", src0, ExprString(fun))
   211  			return
   212  		}
   213  		if got := typ.String(); got != want {
   214  			t.Errorf("%s: got type %s; want %s", src0, got, want)
   215  			return
   216  		}
   217  
   218  		// called function must be a (possibly parenthesized, qualified)
   219  		// identifier denoting the expected built-in
   220  		switch p := fun.(type) {
   221  		case *ast.Ident:
   222  			obj := uses[p]
   223  			if obj == nil {
   224  				t.Errorf("%s: no object found for %s", src0, p)
   225  				return
   226  			}
   227  			bin, _ := obj.(*Builtin)
   228  			if bin == nil {
   229  				t.Errorf("%s: %s does not denote a built-in", src0, p)
   230  				return
   231  			}
   232  			if bin.Name() != name {
   233  				t.Errorf("%s: got built-in %s; want %s", src0, bin.Name(), name)
   234  				return
   235  			}
   236  			return // we're done
   237  
   238  		case *ast.ParenExpr:
   239  			fun = p.X // unpack
   240  
   241  		case *ast.SelectorExpr:
   242  			// built-in from package unsafe - ignore details
   243  			return // we're done
   244  
   245  		default:
   246  			t.Errorf("%s: invalid function call", src0)
   247  			return
   248  		}
   249  	}
   250  }
   251
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