predeclared.go

     1  // Copyright 2024 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 gcimporter
     6  
     7  import (
     8  	"go/types"
     9  	"sync"
    10  )
    11  
    12  // predecl is a cache for the predeclared types in types.Universe.
    13  //
    14  // Cache a distinct result based on the runtime value of any.
    15  // The pointer value of the any type varies based on GODEBUG settings.
    16  var predeclMu sync.Mutex
    17  var predecl map[types.Type][]types.Type
    18  
    19  func predeclared() []types.Type {
    20  	anyt := types.Universe.Lookup("any").Type()
    21  
    22  	predeclMu.Lock()
    23  	defer predeclMu.Unlock()
    24  
    25  	if pre, ok := predecl[anyt]; ok {
    26  		return pre
    27  	}
    28  
    29  	if predecl == nil {
    30  		predecl = make(map[types.Type][]types.Type)
    31  	}
    32  
    33  	decls := []types.Type{ // basic types
    34  		types.Typ[types.Bool],
    35  		types.Typ[types.Int],
    36  		types.Typ[types.Int8],
    37  		types.Typ[types.Int16],
    38  		types.Typ[types.Int32],
    39  		types.Typ[types.Int64],
    40  		types.Typ[types.Uint],
    41  		types.Typ[types.Uint8],
    42  		types.Typ[types.Uint16],
    43  		types.Typ[types.Uint32],
    44  		types.Typ[types.Uint64],
    45  		types.Typ[types.Uintptr],
    46  		types.Typ[types.Float32],
    47  		types.Typ[types.Float64],
    48  		types.Typ[types.Complex64],
    49  		types.Typ[types.Complex128],
    50  		types.Typ[types.String],
    51  
    52  		// basic type aliases
    53  		types.Universe.Lookup("byte").Type(),
    54  		types.Universe.Lookup("rune").Type(),
    55  
    56  		// error
    57  		types.Universe.Lookup("error").Type(),
    58  
    59  		// untyped types
    60  		types.Typ[types.UntypedBool],
    61  		types.Typ[types.UntypedInt],
    62  		types.Typ[types.UntypedRune],
    63  		types.Typ[types.UntypedFloat],
    64  		types.Typ[types.UntypedComplex],
    65  		types.Typ[types.UntypedString],
    66  		types.Typ[types.UntypedNil],
    67  
    68  		// package unsafe
    69  		types.Typ[types.UnsafePointer],
    70  
    71  		// invalid type
    72  		types.Typ[types.Invalid], // only appears in packages with errors
    73  
    74  		// used internally by gc; never used by this package or in .a files
    75  		anyType{},
    76  
    77  		// comparable
    78  		types.Universe.Lookup("comparable").Type(),
    79  
    80  		// any
    81  		anyt,
    82  	}
    83  
    84  	predecl[anyt] = decls
    85  	return decls
    86  }
    87  
    88  type anyType struct{}
    89  
    90  func (t anyType) Underlying() types.Type { return t }
    91  func (t anyType) String() string         { return "any" }
    92
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