analysis - ActiveState ActiveGo 1.8
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Package analysis

import "golang.org/x/tools/godoc/analysis"
Overview
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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.

func Run 

func Run(pta bool, result *Result)

Run runs program analysis and computes the resulting markup, populating *result in a thread-safe manner, first with type information then later with pointer analysis information if enabled by the pta flag.

type FileInfo

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

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

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

type PCGNodeJSON

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

type PackageInfo

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

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

type Result

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. 

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

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

JavaScript's onClickIdent() expects a TypeInfoJSON. 

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