| 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 | "strings" |
| 11 | ) |
| 12 | |
| 13 | // structparm describes a parameter of struct type; it implements the |
| 14 | // "parm" interface. |
| 15 | type structparm struct { |
| 16 | sname string |
| 17 | qname string |
| 18 | fields []parm |
| 19 | isBlank |
| 20 | addrTakenHow |
| 21 | isGenValFunc |
| 22 | skipCompare |
| 23 | } |
| 24 | |
| 25 | func (p structparm) TypeName() string { |
| 26 | return p.sname |
| 27 | } |
| 28 | |
| 29 | func (p structparm) QualName() string { |
| 30 | return p.qname |
| 31 | } |
| 32 | |
| 33 | func (p structparm) Declare(b *bytes.Buffer, prefix string, suffix string, caller bool) { |
| 34 | n := p.sname |
| 35 | if caller { |
| 36 | n = p.qname |
| 37 | } |
| 38 | b.WriteString(fmt.Sprintf("%s %s%s", prefix, n, suffix)) |
| 39 | } |
| 40 | |
| 41 | func (p structparm) FieldName(i int) string { |
| 42 | if p.fields[i].IsBlank() { |
| 43 | return "_" |
| 44 | } |
| 45 | return fmt.Sprintf("F%d", i) |
| 46 | } |
| 47 | |
| 48 | func (p structparm) String() string { |
| 49 | var buf bytes.Buffer |
| 50 | |
| 51 | buf.WriteString(fmt.Sprintf("struct %s {\n", p.sname)) |
| 52 | for fi, f := range p.fields { |
| 53 | buf.WriteString(fmt.Sprintf("%s %s\n", p.FieldName(fi), f.String())) |
| 54 | } |
| 55 | buf.WriteString("}") |
| 56 | return buf.String() |
| 57 | } |
| 58 | |
| 59 | func (p structparm) GenValue(s *genstate, f *funcdef, value int, caller bool) (string, int) { |
| 60 | var buf bytes.Buffer |
| 61 | |
| 62 | verb(5, "structparm.GenValue(%d)", value) |
| 63 | |
| 64 | n := p.sname |
| 65 | if caller { |
| 66 | n = p.qname |
| 67 | } |
| 68 | buf.WriteString(fmt.Sprintf("%s{", n)) |
| 69 | nbfi := 0 |
| 70 | for fi, fld := range p.fields { |
| 71 | var valstr string |
| 72 | valstr, value = s.GenValue(f, fld, value, caller) |
| 73 | if p.fields[fi].IsBlank() { |
| 74 | buf.WriteString("/* ") |
| 75 | valstr = strings.ReplaceAll(valstr, "/*", "[[") |
| 76 | valstr = strings.ReplaceAll(valstr, "*/", "]]") |
| 77 | } else { |
| 78 | writeCom(&buf, nbfi) |
| 79 | } |
| 80 | buf.WriteString(p.FieldName(fi) + ": ") |
| 81 | buf.WriteString(valstr) |
| 82 | if p.fields[fi].IsBlank() { |
| 83 | buf.WriteString(" */") |
| 84 | } else { |
| 85 | nbfi++ |
| 86 | } |
| 87 | } |
| 88 | buf.WriteString("}") |
| 89 | return buf.String(), value |
| 90 | } |
| 91 | |
| 92 | func (p structparm) IsControl() bool { |
| 93 | return false |
| 94 | } |
| 95 | |
| 96 | func (p structparm) NumElements() int { |
| 97 | ne := 0 |
| 98 | for _, f := range p.fields { |
| 99 | ne += f.NumElements() |
| 100 | } |
| 101 | return ne |
| 102 | } |
| 103 | |
| 104 | func (p structparm) GenElemRef(elidx int, path string) (string, parm) { |
| 105 | ct := 0 |
| 106 | verb(4, "begin GenElemRef(%d,%s) on %s", elidx, path, p.String()) |
| 107 | |
| 108 | for fi, f := range p.fields { |
| 109 | fne := f.NumElements() |
| 110 | |
| 111 | //verb(4, "+ examining field %d fne %d ct %d", fi, fne, ct) |
| 112 | |
| 113 | // Empty field. Continue on. |
| 114 | if elidx == ct && fne == 0 { |
| 115 | continue |
| 116 | } |
| 117 | |
| 118 | // Is this field the element we're interested in? |
| 119 | if fne == 1 && elidx == ct { |
| 120 | |
| 121 | // The field in question may be a composite that has only |
| 122 | // multiple elements but a single non-zero-sized element. |
| 123 | // If this is the case, keep going. |
| 124 | if sp, ok := f.(*structparm); ok { |
| 125 | if len(sp.fields) > 1 { |
| 126 | ppath := fmt.Sprintf("%s.F%d", path, fi) |
| 127 | if p.fields[fi].IsBlank() || path == "_" { |
| 128 | ppath = "_" |
| 129 | } |
| 130 | return f.GenElemRef(elidx-ct, ppath) |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | verb(4, "found field %d type %s in GenElemRef(%d,%s)", fi, f.TypeName(), elidx, path) |
| 135 | ppath := fmt.Sprintf("%s.F%d", path, fi) |
| 136 | if p.fields[fi].IsBlank() || path == "_" { |
| 137 | ppath = "_" |
| 138 | } |
| 139 | return ppath, f |
| 140 | } |
| 141 | |
| 142 | // Is the element we want somewhere inside this field? |
| 143 | if fne > 1 && elidx >= ct && elidx < ct+fne { |
| 144 | ppath := fmt.Sprintf("%s.F%d", path, fi) |
| 145 | if p.fields[fi].IsBlank() || path == "_" { |
| 146 | ppath = "_" |
| 147 | } |
| 148 | return f.GenElemRef(elidx-ct, ppath) |
| 149 | } |
| 150 | |
| 151 | ct += fne |
| 152 | } |
| 153 | panic(fmt.Sprintf("GenElemRef failed for struct %s elidx %d", p.TypeName(), elidx)) |
| 154 | } |
| 155 | |
| 156 | func (p structparm) HasPointer() bool { |
| 157 | for _, f := range p.fields { |
| 158 | if f.HasPointer() { |
| 159 | return true |
| 160 | } |
| 161 | } |
| 162 | return false |
| 163 | } |
| 164 |
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