| 1 | // Copyright 2021 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 generator |
| 6 | |
| 7 | import ( |
| 8 | "bytes" |
| 9 | "fmt" |
| 10 | ) |
| 11 | |
| 12 | // arrayparm describes a parameter of array type; it implements the |
| 13 | // "parm" interface. |
| 14 | type arrayparm struct { |
| 15 | aname string |
| 16 | qname string |
| 17 | nelements uint8 |
| 18 | eltype parm |
| 19 | slice bool |
| 20 | isBlank |
| 21 | addrTakenHow |
| 22 | isGenValFunc |
| 23 | skipCompare |
| 24 | } |
| 25 | |
| 26 | func (p arrayparm) IsControl() bool { |
| 27 | return false |
| 28 | } |
| 29 | |
| 30 | func (p arrayparm) TypeName() string { |
| 31 | return p.aname |
| 32 | } |
| 33 | |
| 34 | func (p arrayparm) QualName() string { |
| 35 | return p.qname |
| 36 | } |
| 37 | |
| 38 | func (p arrayparm) Declare(b *bytes.Buffer, prefix string, suffix string, caller bool) { |
| 39 | n := p.aname |
| 40 | if caller { |
| 41 | n = p.qname |
| 42 | } |
| 43 | b.WriteString(fmt.Sprintf("%s %s%s", prefix, n, suffix)) |
| 44 | } |
| 45 | |
| 46 | func (p arrayparm) String() string { |
| 47 | return fmt.Sprintf("%s %d-element array of %s", p.aname, p.nelements, p.eltype.String()) |
| 48 | } |
| 49 | |
| 50 | func (p arrayparm) GenValue(s *genstate, f *funcdef, value int, caller bool) (string, int) { |
| 51 | var buf bytes.Buffer |
| 52 | |
| 53 | verb(5, "arrayparm.GenValue(%d)", value) |
| 54 | |
| 55 | n := p.aname |
| 56 | if caller { |
| 57 | n = p.qname |
| 58 | } |
| 59 | buf.WriteString(fmt.Sprintf("%s{", n)) |
| 60 | for i := 0; i < int(p.nelements); i++ { |
| 61 | var valstr string |
| 62 | valstr, value = s.GenValue(f, p.eltype, value, caller) |
| 63 | writeCom(&buf, i) |
| 64 | buf.WriteString(valstr) |
| 65 | } |
| 66 | buf.WriteString("}") |
| 67 | return buf.String(), value |
| 68 | } |
| 69 | |
| 70 | func (p arrayparm) GenElemRef(elidx int, path string) (string, parm) { |
| 71 | ene := p.eltype.NumElements() |
| 72 | verb(4, "begin GenElemRef(%d,%s) on %s ene %d", elidx, path, p.String(), ene) |
| 73 | |
| 74 | // For empty arrays, convention is to return empty string |
| 75 | if ene == 0 { |
| 76 | return "", &p |
| 77 | } |
| 78 | |
| 79 | // Find slot within array of element of interest |
| 80 | slot := elidx / ene |
| 81 | |
| 82 | // If this is the element we're interested in, return it |
| 83 | if ene == 1 { |
| 84 | verb(4, "hit scalar element") |
| 85 | epath := fmt.Sprintf("%s[%d]", path, slot) |
| 86 | if path == "_" || p.IsBlank() { |
| 87 | epath = "_" |
| 88 | } |
| 89 | return epath, p.eltype |
| 90 | } |
| 91 | |
| 92 | verb(4, "recur slot=%d GenElemRef(%d,...)", slot, elidx-(slot*ene)) |
| 93 | |
| 94 | // Otherwise our victim is somewhere inside the slot |
| 95 | ppath := fmt.Sprintf("%s[%d]", path, slot) |
| 96 | if p.IsBlank() { |
| 97 | ppath = "_" |
| 98 | } |
| 99 | return p.eltype.GenElemRef(elidx-(slot*ene), ppath) |
| 100 | } |
| 101 | |
| 102 | func (p arrayparm) NumElements() int { |
| 103 | return p.eltype.NumElements() * int(p.nelements) |
| 104 | } |
| 105 | |
| 106 | func (p arrayparm) HasPointer() bool { |
| 107 | return p.eltype.HasPointer() || p.slice |
| 108 | } |
| 109 |
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