blob: 24f9604c100c56ebf4948f90727fcf36f39fc098 [file] [log] [blame]
// Copyright 2021 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package template
import (
"bytes"
"context"
"fmt"
"text/template/parse"
"unicode/utf8"
"golang.org/x/tools/internal/event"
"golang.org/x/tools/gopls/internal/lsp/protocol"
"golang.org/x/tools/gopls/internal/lsp/source"
)
// in local coordinates, to be translated to protocol.DocumentSymbol
type symbol struct {
start int // for sorting
length int // in runes (unicode code points)
name string
kind protocol.SymbolKind
vardef bool // is this a variable definition?
// do we care about selection range, or children?
// no children yet, and selection range is the same as range
}
func (s symbol) String() string {
return fmt.Sprintf("{%d,%d,%s,%s,%v}", s.start, s.length, s.name, s.kind, s.vardef)
}
// for FieldNode or VariableNode (or ChainNode?)
func (p *Parsed) fields(flds []string, x parse.Node) []symbol {
ans := []symbol{}
// guessing that there are no embedded blanks allowed. The doc is unclear
lookfor := ""
switch x.(type) {
case *parse.FieldNode:
for _, f := range flds {
lookfor += "." + f // quadratic, but probably ok
}
case *parse.VariableNode:
lookfor = flds[0]
for i := 1; i < len(flds); i++ {
lookfor += "." + flds[i]
}
case *parse.ChainNode: // PJW, what are these?
for _, f := range flds {
lookfor += "." + f // quadratic, but probably ok
}
default:
// If these happen they will happen even if gopls is restarted
// and the users does the same thing, so it is better not to panic.
// context.Background() is used because we don't have access
// to any other context. [we could, but it would be complicated]
event.Log(context.Background(), fmt.Sprintf("%T unexpected in fields()", x))
return nil
}
if len(lookfor) == 0 {
event.Log(context.Background(), fmt.Sprintf("no strings in fields() %#v", x))
return nil
}
startsAt := int(x.Position())
ix := bytes.Index(p.buf[startsAt:], []byte(lookfor)) // HasPrefix? PJW?
if ix < 0 || ix > len(lookfor) { // lookfor expected to be at start (or so)
// probably golang.go/#43388, so back up
startsAt -= len(flds[0]) + 1
ix = bytes.Index(p.buf[startsAt:], []byte(lookfor)) // ix might be 1? PJW
if ix < 0 {
return ans
}
}
at := ix + startsAt
for _, f := range flds {
at += 1 // .
kind := protocol.Method
if f[0] == '$' {
kind = protocol.Variable
}
sym := symbol{name: f, kind: kind, start: at, length: utf8.RuneCount([]byte(f))}
if kind == protocol.Variable && len(p.stack) > 1 {
if pipe, ok := p.stack[len(p.stack)-2].(*parse.PipeNode); ok {
for _, y := range pipe.Decl {
if x == y {
sym.vardef = true
}
}
}
}
ans = append(ans, sym)
at += len(f)
}
return ans
}
func (p *Parsed) findSymbols() {
if len(p.stack) == 0 {
return
}
n := p.stack[len(p.stack)-1]
pop := func() {
p.stack = p.stack[:len(p.stack)-1]
}
if n == nil { // allowing nil simplifies the code
pop()
return
}
nxt := func(nd parse.Node) {
p.stack = append(p.stack, nd)
p.findSymbols()
}
switch x := n.(type) {
case *parse.ActionNode:
nxt(x.Pipe)
case *parse.BoolNode:
// need to compute the length from the value
msg := fmt.Sprintf("%v", x.True)
p.symbols = append(p.symbols, symbol{start: int(x.Pos), length: len(msg), kind: protocol.Boolean})
case *parse.BranchNode:
nxt(x.Pipe)
nxt(x.List)
nxt(x.ElseList)
case *parse.ChainNode:
p.symbols = append(p.symbols, p.fields(x.Field, x)...)
nxt(x.Node)
case *parse.CommandNode:
for _, a := range x.Args {
nxt(a)
}
//case *parse.CommentNode: // go 1.16
// log.Printf("implement %d", x.Type())
case *parse.DotNode:
sym := symbol{name: "dot", kind: protocol.Variable, start: int(x.Pos), length: 1}
p.symbols = append(p.symbols, sym)
case *parse.FieldNode:
p.symbols = append(p.symbols, p.fields(x.Ident, x)...)
case *parse.IdentifierNode:
sym := symbol{name: x.Ident, kind: protocol.Function, start: int(x.Pos),
length: utf8.RuneCount([]byte(x.Ident))}
p.symbols = append(p.symbols, sym)
case *parse.IfNode:
nxt(&x.BranchNode)
case *parse.ListNode:
if x != nil { // wretched typed nils. Node should have an IfNil
for _, nd := range x.Nodes {
nxt(nd)
}
}
case *parse.NilNode:
sym := symbol{name: "nil", kind: protocol.Constant, start: int(x.Pos), length: 3}
p.symbols = append(p.symbols, sym)
case *parse.NumberNode:
// no name; ascii
p.symbols = append(p.symbols, symbol{start: int(x.Pos), length: len(x.Text), kind: protocol.Number})
case *parse.PipeNode:
if x == nil { // {{template "foo"}}
return
}
for _, d := range x.Decl {
nxt(d)
}
for _, c := range x.Cmds {
nxt(c)
}
case *parse.RangeNode:
nxt(&x.BranchNode)
case *parse.StringNode:
// no name
sz := utf8.RuneCount([]byte(x.Text))
p.symbols = append(p.symbols, symbol{start: int(x.Pos), length: sz, kind: protocol.String})
case *parse.TemplateNode: // invoking a template
// x.Pos points to the quote before the name
p.symbols = append(p.symbols, symbol{name: x.Name, kind: protocol.Package, start: int(x.Pos) + 1,
length: utf8.RuneCount([]byte(x.Name))})
nxt(x.Pipe)
case *parse.TextNode:
if len(x.Text) == 1 && x.Text[0] == '\n' {
break
}
// nothing to report, but build one for hover
sz := utf8.RuneCount([]byte(x.Text))
p.symbols = append(p.symbols, symbol{start: int(x.Pos), length: sz, kind: protocol.Constant})
case *parse.VariableNode:
p.symbols = append(p.symbols, p.fields(x.Ident, x)...)
case *parse.WithNode:
nxt(&x.BranchNode)
}
pop()
}
// DocumentSymbols returns a hierarchy of the symbols defined in a template file.
// (The hierarchy is flat. SymbolInformation might be better.)
func DocumentSymbols(snapshot source.Snapshot, fh source.FileHandle) ([]protocol.DocumentSymbol, error) {
buf, err := fh.Read()
if err != nil {
return nil, err
}
p := parseBuffer(buf)
if p.ParseErr != nil {
return nil, p.ParseErr
}
var ans []protocol.DocumentSymbol
for _, s := range p.symbols {
if s.kind == protocol.Constant {
continue
}
d := kindStr(s.kind)
if d == "Namespace" {
d = "Template"
}
if s.vardef {
d += "(def)"
} else {
d += "(use)"
}
r := p.Range(s.start, s.length)
y := protocol.DocumentSymbol{
Name: s.name,
Detail: d,
Kind: s.kind,
Range: r,
SelectionRange: r, // or should this be the entire {{...}}?
}
ans = append(ans, y)
}
return ans, nil
}