analysis

Documentation

Overview

Package analysis performs type and pointer analysis and generates mark-up for the Go source view.

The Run method populates a Result object by running type and (optionally) pointer analysis. The Result object is thread-safe and at all times may be accessed by a serving thread, even as it is progressively populated as analysis facts are derived.

The Result is a mapping from each godoc file URL (e.g. /src/fmt/print.go) to information about that file. The information is a list of HTML markup links and a JSON array of structured data values. Some of the links call client-side JavaScript functions that index this array.

The analysis computes mark-up for the following relations:

IMPORTS: for each ast.ImportSpec, the package that it denotes.

RESOLUTION: for each ast.Ident, its kind and type, and the location of its definition.

METHOD SETS, IMPLEMENTS: for each ast.Ident defining a named type, its method-set, the set of interfaces it implements or is implemented by, and its size/align values.

CALLERS, CALLEES: for each function declaration ('func' token), its callers, and for each call-site ('(' token), its callees.

CALLGRAPH: the package docs include an interactive viewer for the intra-package call graph of "fmt".

CHANNEL PEERS: for each channel operation make/<-/close, the set of other channel ops that alias the same channel(s).

ERRORS: for each locus of a frontend (scanner/parser/type) error, the location is highlighted in red and hover text provides the compiler error message.

Index

• type FileInfo
• type Link
• type PCGNodeJSON
• type PackageInfo
• type Result
  • func (res *Result) FileInfo(url string) (fi FileInfo)
  • func (res *Result) PackageInfo(importPath string) PackageInfo
  • func (res *Result) Status() string
• type TypeInfoJSON

Types

type FileInfo

type FileInfo struct {
	Data  []interface{} // JSON serializable values
	Links []Link        // HTML link markup
}

FileInfo holds analysis information for the source file view. Clients must not mutate it.

type Link

type Link interface {
	Start() int
	End() int
	Write(w io.Writer, _ int, start bool) // the godoc.LinkWriter signature
}

A Link is an HTML decoration of the bytes [Start, End) of a file. Write is called before/after those bytes to emit the mark-up.

type PCGNodeJSON

type PCGNodeJSON struct {
	Func    anchorJSON
	Callees []int // indices within CALLGRAPH of nodes called by this one
}

JavaScript's cgAddChild requires a global array of PCGNodeJSON called CALLGRAPH, representing the intra-package call graph. The first element is special and represents "all external callers".

type PackageInfo

type PackageInfo struct {
	CallGraph      []*PCGNodeJSON
	CallGraphIndex map[string]int
	Types          []*TypeInfoJSON
}

PackageInfo holds analysis information for the package view. Clients must not mutate it.

type Result

type Result struct {
	// contains filtered or unexported fields
}

Result contains the results of analysis. The result contains a mapping from filenames to a set of HTML links and JavaScript data referenced by the links.

func (*Result) FileInfo

func (res *Result) FileInfo(url string) (fi FileInfo)

FileInfo returns new slices containing opaque JSON values and the HTML link markup for the specified godoc file URL. Thread-safe. Callers must not mutate the elements. It returns "zero" if no data is available.

func (*Result) PackageInfo

func (res *Result) PackageInfo(importPath string) PackageInfo

PackageInfo returns new slices of JSON values for the callgraph and type info for the specified package. Thread-safe. Callers must not mutate its fields. PackageInfo returns "zero" if no data is available.

func (*Result) Status

func (res *Result) Status() string

Status returns a human-readable description of the current analysis status.

type TypeInfoJSON

type TypeInfoJSON struct {
	Name        string // type name
	Size, Align int64
	Methods     []anchorJSON
	ImplGroups  []implGroupJSON
}

JavaScript's onClickIdent() expects a TypeInfoJSON.