github.com/goplus/llgo@v0.8.3/internal/runtime/z_slice.go (about) 1 /* 2 * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package runtime 18 19 import ( 20 "unsafe" 21 22 "github.com/goplus/llgo/internal/runtime/c" 23 ) 24 25 // ----------------------------------------------------------------------------- 26 27 // Slice is the runtime representation of a slice. 28 type Slice struct { 29 data unsafe.Pointer 30 len int 31 cap int 32 } 33 34 // NilSlice returns a nil slice. 35 func NilSlice() Slice { 36 return Slice{nil, 0, 0} 37 } 38 39 // NewSlice creates a new slice. 40 func NewSlice(data unsafe.Pointer, len, cap int) Slice { 41 return Slice{data, len, cap} 42 } 43 44 func NewSlice3(base unsafe.Pointer, eltSize, cap, i, j, k int) (s Slice) { 45 if i < 0 || j < i || k < j || k > cap { 46 panic("slice index out of bounds") 47 } 48 s.len = j - i 49 s.cap = k - i 50 if k-i > 0 { 51 s.data = c.Advance(base, i*eltSize) 52 } else { 53 s.data = base 54 } 55 return 56 } 57 58 // SliceLen returns the length of a slice. 59 func SliceLen(s Slice) int { 60 return s.len 61 } 62 63 // SliceCap returns the capacity of a slice. 64 func SliceCap(s Slice) int { 65 return s.cap 66 } 67 68 // SliceData returns the data pointer of a slice. 69 func SliceData(s Slice) unsafe.Pointer { 70 return s.data 71 } 72 73 // SliceAppend append elem data and returns a slice. 74 func SliceAppend(src Slice, data unsafe.Pointer, num, etSize int) Slice { 75 if etSize == 0 { 76 return src 77 } 78 oldLen := src.len 79 newLen := src.len + num 80 if newLen > src.cap { 81 newCap := nextslicecap(newLen, src.cap) 82 p := AllocZ(uintptr(newCap * etSize)) 83 if oldLen != 0 { 84 c.Memcpy(p, src.data, uintptr(oldLen*etSize)) 85 } 86 src.data = p 87 src.cap = newCap 88 } 89 src.len = newLen 90 c.Memcpy(c.Advance(src.data, oldLen*etSize), data, uintptr(num*etSize)) 91 return src 92 } 93 94 // -----------------------------------------------------------------------------