github.com/v2pro/plz@v0.0.0-20221028024117-e5f9aec5b631/reflect2/unsafe_link.go (about)

     1  package reflect2
     2  
     3  import "unsafe"
     4  
     5  //go:linkname unsafe_New reflect.unsafe_New
     6  func unsafe_New(rtype unsafe.Pointer) unsafe.Pointer
     7  
     8  //go:linkname typedmemmove reflect.typedmemmove
     9  func typedmemmove(rtype unsafe.Pointer, dst, src unsafe.Pointer)
    10  
    11  //go:linkname unsafe_NewArray reflect.unsafe_NewArray
    12  func unsafe_NewArray(rtype unsafe.Pointer, length int) unsafe.Pointer
    13  
    14  // typedslicecopy copies a slice of elemType values from src to dst,
    15  // returning the number of elements copied.
    16  //go:linkname typedslicecopy reflect.typedslicecopy
    17  //go:noescape
    18  func typedslicecopy(elemType unsafe.Pointer, dst, src sliceHeader) int
    19  
    20  //go:linkname mapassign reflect.mapassign
    21  //go:noescape
    22  func mapassign(rtype unsafe.Pointer, m unsafe.Pointer, key, val unsafe.Pointer)
    23  
    24  //go:linkname mapaccess reflect.mapaccess
    25  //go:noescape
    26  func mapaccess(rtype unsafe.Pointer, m unsafe.Pointer, key unsafe.Pointer) (val unsafe.Pointer)
    27  
    28  // m escapes into the return value, but the caller of mapiterinit
    29  // doesn't let the return value escape.
    30  //go:noescape
    31  //go:linkname mapiterinit reflect.mapiterinit
    32  func mapiterinit(rtype unsafe.Pointer, m unsafe.Pointer) *hiter
    33  
    34  //go:noescape
    35  //go:linkname mapiternext reflect.mapiternext
    36  func mapiternext(it *hiter)
    37  
    38  //go:linkname ifaceE2I reflect.ifaceE2I
    39  func ifaceE2I(rtype unsafe.Pointer, src interface{}, dst unsafe.Pointer)
    40  
    41  // A hash iteration structure.
    42  // If you modify hiter, also change cmd/internal/gc/reflect.go to indicate
    43  // the layout of this structure.
    44  type hiter struct {
    45  	key   unsafe.Pointer // Must be in first position.  Write nil to indicate iteration end (see cmd/internal/gc/range.go).
    46  	value unsafe.Pointer // Must be in second position (see cmd/internal/gc/range.go).
    47  	// rest fields are ignored
    48  }
    49  
    50  // add returns p+x.
    51  //
    52  // The whySafe string is ignored, so that the function still inlines
    53  // as efficiently as p+x, but all call sites should use the string to
    54  // record why the addition is safe, which is to say why the addition
    55  // does not cause x to advance to the very end of p's allocation
    56  // and therefore point incorrectly at the next block in memory.
    57  func add(p unsafe.Pointer, x uintptr, whySafe string) unsafe.Pointer {
    58  	return unsafe.Pointer(uintptr(p) + x)
    59  }
    60  
    61  // arrayAt returns the i-th element of p,
    62  // an array whose elements are eltSize bytes wide.
    63  // The array pointed at by p must have at least i+1 elements:
    64  // it is invalid (but impossible to check here) to pass i >= len,
    65  // because then the result will point outside the array.
    66  // whySafe must explain why i < len. (Passing "i < len" is fine;
    67  // the benefit is to surface this assumption at the call site.)
    68  func arrayAt(p unsafe.Pointer, i int, eltSize uintptr, whySafe string) unsafe.Pointer {
    69  	return add(p, uintptr(i)*eltSize, "i < len")
    70  }