| 1 | // Copyright 2014 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 analysis performs type and pointer analysis |
| 6 | // and generates mark-up for the Go source view. |
| 7 | // |
| 8 | // The Run method populates a Result object by running type and |
| 9 | // (optionally) pointer analysis. The Result object is thread-safe |
| 10 | // and at all times may be accessed by a serving thread, even as it is |
| 11 | // progressively populated as analysis facts are derived. |
| 12 | // |
| 13 | // The Result is a mapping from each godoc file URL |
| 14 | // (e.g. /src/fmt/print.go) to information about that file. The |
| 15 | // information is a list of HTML markup links and a JSON array of |
| 16 | // structured data values. Some of the links call client-side |
| 17 | // JavaScript functions that index this array. |
| 18 | // |
| 19 | // The analysis computes mark-up for the following relations: |
| 20 | // |
| 21 | // IMPORTS: for each ast.ImportSpec, the package that it denotes. |
| 22 | // |
| 23 | // RESOLUTION: for each ast.Ident, its kind and type, and the location |
| 24 | // of its definition. |
| 25 | // |
| 26 | // METHOD SETS, IMPLEMENTS: for each ast.Ident defining a named type, |
| 27 | // its method-set, the set of interfaces it implements or is |
| 28 | // implemented by, and its size/align values. |
| 29 | // |
| 30 | // CALLERS, CALLEES: for each function declaration ('func' token), its |
| 31 | // callers, and for each call-site ('(' token), its callees. |
| 32 | // |
| 33 | // CALLGRAPH: the package docs include an interactive viewer for the |
| 34 | // intra-package call graph of "fmt". |
| 35 | // |
| 36 | // CHANNEL PEERS: for each channel operation make/<-/close, the set of |
| 37 | // other channel ops that alias the same channel(s). |
| 38 | // |
| 39 | // ERRORS: for each locus of a frontend (scanner/parser/type) error, the |
| 40 | // location is highlighted in red and hover text provides the compiler |
| 41 | // error message. |
| 42 | package analysis // import "golang.org/x/tools/godoc/analysis" |
| 43 | |
| 44 | import ( |
| 45 | "io" |
| 46 | "sort" |
| 47 | "sync" |
| 48 | ) |
| 49 | |
| 50 | // -- links ------------------------------------------------------------ |
| 51 | |
| 52 | // A Link is an HTML decoration of the bytes [Start, End) of a file. |
| 53 | // Write is called before/after those bytes to emit the mark-up. |
| 54 | type Link interface { |
| 55 | Start() int |
| 56 | End() int |
| 57 | Write(w io.Writer, _ int, start bool) // the godoc.LinkWriter signature |
| 58 | } |
| 59 | |
| 60 | // -- fileInfo --------------------------------------------------------- |
| 61 | |
| 62 | // FileInfo holds analysis information for the source file view. |
| 63 | // Clients must not mutate it. |
| 64 | type FileInfo struct { |
| 65 | Data []interface{} // JSON serializable values |
| 66 | Links []Link // HTML link markup |
| 67 | } |
| 68 | |
| 69 | // A fileInfo is the server's store of hyperlinks and JSON data for a |
| 70 | // particular file. |
| 71 | type fileInfo struct { |
| 72 | mu sync.Mutex |
| 73 | data []interface{} // JSON objects |
| 74 | links []Link |
| 75 | sorted bool |
| 76 | hasErrors bool // TODO(adonovan): surface this in the UI |
| 77 | } |
| 78 | |
| 79 | // get returns the file info in external form. |
| 80 | // Callers must not mutate its fields. |
| 81 | func (fi *fileInfo) get() FileInfo { |
| 82 | var r FileInfo |
| 83 | // Copy slices, to avoid races. |
| 84 | fi.mu.Lock() |
| 85 | r.Data = append(r.Data, fi.data...) |
| 86 | if !fi.sorted { |
| 87 | sort.Sort(linksByStart(fi.links)) |
| 88 | fi.sorted = true |
| 89 | } |
| 90 | r.Links = append(r.Links, fi.links...) |
| 91 | fi.mu.Unlock() |
| 92 | return r |
| 93 | } |
| 94 | |
| 95 | // PackageInfo holds analysis information for the package view. |
| 96 | // Clients must not mutate it. |
| 97 | type PackageInfo struct { |
| 98 | CallGraph []*PCGNodeJSON |
| 99 | CallGraphIndex map[string]int |
| 100 | Types []*TypeInfoJSON |
| 101 | } |
| 102 | |
| 103 | type pkgInfo struct { |
| 104 | mu sync.Mutex |
| 105 | callGraph []*PCGNodeJSON |
| 106 | callGraphIndex map[string]int // keys are (*ssa.Function).RelString() |
| 107 | types []*TypeInfoJSON // type info for exported types |
| 108 | } |
| 109 | |
| 110 | // get returns the package info in external form. |
| 111 | // Callers must not mutate its fields. |
| 112 | func (pi *pkgInfo) get() PackageInfo { |
| 113 | var r PackageInfo |
| 114 | // Copy slices, to avoid races. |
| 115 | pi.mu.Lock() |
| 116 | r.CallGraph = append(r.CallGraph, pi.callGraph...) |
| 117 | r.CallGraphIndex = pi.callGraphIndex |
| 118 | r.Types = append(r.Types, pi.types...) |
| 119 | pi.mu.Unlock() |
| 120 | return r |
| 121 | } |
| 122 | |
| 123 | // -- Result ----------------------------------------------------------- |
| 124 | |
| 125 | // Result contains the results of analysis. |
| 126 | // The result contains a mapping from filenames to a set of HTML links |
| 127 | // and JavaScript data referenced by the links. |
| 128 | type Result struct { |
| 129 | mu sync.Mutex // guards maps (but not their contents) |
| 130 | status string // global analysis status |
| 131 | fileInfos map[string]*fileInfo // keys are godoc file URLs |
| 132 | pkgInfos map[string]*pkgInfo // keys are import paths |
| 133 | } |
| 134 | |
| 135 | // fileInfo returns the fileInfo for the specified godoc file URL, |
| 136 | // constructing it as needed. Thread-safe. |
| 137 | func (res *Result) fileInfo(url string) *fileInfo { |
| 138 | res.mu.Lock() |
| 139 | fi, ok := res.fileInfos[url] |
| 140 | if !ok { |
| 141 | if res.fileInfos == nil { |
| 142 | res.fileInfos = make(map[string]*fileInfo) |
| 143 | } |
| 144 | fi = new(fileInfo) |
| 145 | res.fileInfos[url] = fi |
| 146 | } |
| 147 | res.mu.Unlock() |
| 148 | return fi |
| 149 | } |
| 150 | |
| 151 | // Status returns a human-readable description of the current analysis status. |
| 152 | func (res *Result) Status() string { |
| 153 | res.mu.Lock() |
| 154 | defer res.mu.Unlock() |
| 155 | return res.status |
| 156 | } |
| 157 | |
| 158 | // FileInfo returns new slices containing opaque JSON values and the |
| 159 | // HTML link markup for the specified godoc file URL. Thread-safe. |
| 160 | // Callers must not mutate the elements. |
| 161 | // It returns "zero" if no data is available. |
| 162 | func (res *Result) FileInfo(url string) (fi FileInfo) { |
| 163 | return res.fileInfo(url).get() |
| 164 | } |
| 165 | |
| 166 | // pkgInfo returns the pkgInfo for the specified import path, |
| 167 | // constructing it as needed. Thread-safe. |
| 168 | func (res *Result) pkgInfo(importPath string) *pkgInfo { |
| 169 | res.mu.Lock() |
| 170 | pi, ok := res.pkgInfos[importPath] |
| 171 | if !ok { |
| 172 | if res.pkgInfos == nil { |
| 173 | res.pkgInfos = make(map[string]*pkgInfo) |
| 174 | } |
| 175 | pi = new(pkgInfo) |
| 176 | res.pkgInfos[importPath] = pi |
| 177 | } |
| 178 | res.mu.Unlock() |
| 179 | return pi |
| 180 | } |
| 181 | |
| 182 | // PackageInfo returns new slices of JSON values for the callgraph and |
| 183 | // type info for the specified package. Thread-safe. |
| 184 | // Callers must not mutate its fields. |
| 185 | // PackageInfo returns "zero" if no data is available. |
| 186 | func (res *Result) PackageInfo(importPath string) PackageInfo { |
| 187 | return res.pkgInfo(importPath).get() |
| 188 | } |
| 189 | |
| 190 | type linksByStart []Link |
| 191 | |
| 192 | func (a linksByStart) Less(i, j int) bool { return a[i].Start() < a[j].Start() } |
| 193 | func (a linksByStart) Swap(i, j int) { a[i], a[j] = a[j], a[i] } |
| 194 | func (a linksByStart) Len() int { return len(a) } |
| 195 |
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