Giant blob of minor changes

[dotfiles/.git] / .config / coc / extensions / coc-go-data / tools / pkg / mod / golang.org / x / tools@v0.0.0-20201105173854-bc9fc8d8c4bc / internal / lsp / source / view.go

// Copyright 2018 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 source

import (
        "bytes"
        "context"
        "fmt"
        "go/ast"
        "go/token"
        "go/types"
        "io"
        "strings"

        "golang.org/x/mod/modfile"
        "golang.org/x/mod/module"
        "golang.org/x/tools/go/analysis"
        "golang.org/x/tools/internal/gocommand"
        "golang.org/x/tools/internal/imports"
        "golang.org/x/tools/internal/lsp/protocol"
        "golang.org/x/tools/internal/span"
        errors "golang.org/x/xerrors"
)

// Snapshot represents the current state for the given view.
type Snapshot interface {
        ID() uint64

        // View returns the View associated with this snapshot.
        View() View

        // Fileset returns the Fileset used to parse all the Go files in this snapshot.
        FileSet() *token.FileSet

        // ValidBuildConfiguration returns true if there is some error in the
        // user's workspace. In particular, if they are both outside of a module
        // and their GOPATH.
        ValidBuildConfiguration() bool

        // WriteEnv writes the view-specific environment to the io.Writer.
        WriteEnv(ctx context.Context, w io.Writer) error

        // FindFile returns the FileHandle for the given URI, if it is already
        // in the given snapshot.
        FindFile(uri span.URI) VersionedFileHandle

        // GetVersionedFile returns the VersionedFileHandle for a given URI,
        // initializing it if it is not already part of the snapshot.
        GetVersionedFile(ctx context.Context, uri span.URI) (VersionedFileHandle, error)

        // GetFile returns the FileHandle for a given URI, initializing it if it is
        // not already part of the snapshot.
        GetFile(ctx context.Context, uri span.URI) (FileHandle, error)

        // AwaitInitialized waits until the snapshot's view is initialized.
        AwaitInitialized(ctx context.Context)

        // IsOpen returns whether the editor currently has a file open.
        IsOpen(uri span.URI) bool

        // IgnoredFile reports if a file would be ignored by a `go list` of the whole
        // workspace.
        IgnoredFile(uri span.URI) bool

        // ParseGo returns the parsed AST for the file.
        // If the file is not available, returns nil and an error.
        ParseGo(ctx context.Context, fh FileHandle, mode ParseMode) (*ParsedGoFile, error)

        // PosToField is a cache of *ast.Fields by token.Pos. This allows us
        // to quickly find corresponding *ast.Field node given a *types.Var.
        // We must refer to the AST to render type aliases properly when
        // formatting signatures and other types.
        PosToField(ctx context.Context, pgf *ParsedGoFile) (map[token.Pos]*ast.Field, error)

        // PosToDecl maps certain objects' positions to their surrounding
        // ast.Decl. This mapping is used when building the documentation
        // string for the objects.
        PosToDecl(ctx context.Context, pgf *ParsedGoFile) (map[token.Pos]ast.Decl, error)

        // Analyze runs the analyses for the given package at this snapshot.
        Analyze(ctx context.Context, pkgID string, analyzers ...*analysis.Analyzer) ([]*Error, error)

        // RunGoCommandPiped runs the given `go` command, writing its output
        // to stdout and stderr. Verb, Args, and WorkingDir must be specified.
        RunGoCommandPiped(ctx context.Context, mode InvocationMode, inv *gocommand.Invocation, stdout, stderr io.Writer) error

        // RunGoCommandDirect runs the given `go` command. Verb, Args, and
        // WorkingDir must be specified.
        RunGoCommandDirect(ctx context.Context, mode InvocationMode, inv *gocommand.Invocation) (*bytes.Buffer, error)

        // RunProcessEnvFunc runs fn with the process env for this snapshot's view.
        // Note: the process env contains cached module and filesystem state.
        RunProcessEnvFunc(ctx context.Context, fn func(*imports.Options) error) error

        // ModFiles are the go.mod files enclosed in the snapshot's view and known
        // to the snapshot.
        ModFiles() []span.URI

        // ParseMod is used to parse go.mod files.
        ParseMod(ctx context.Context, fh FileHandle) (*ParsedModule, error)

        // ModWhy returns the results of `go mod why` for the module specified by
        // the given go.mod file.
        ModWhy(ctx context.Context, fh FileHandle) (map[string]string, error)

        // ModUpgrade returns the possible updates for the module specified by the
        // given go.mod file.
        ModUpgrade(ctx context.Context, fh FileHandle) (map[string]string, error)

        // ModTidy returns the results of `go mod tidy` for the module specified by
        // the given go.mod file.
        ModTidy(ctx context.Context, fh FileHandle) (*TidiedModule, error)

        // GoModForFile returns the URI of the go.mod file for the given URI.
        GoModForFile(ctx context.Context, uri span.URI) span.URI

        // BuiltinPackage returns information about the special builtin package.
        BuiltinPackage(ctx context.Context) (*BuiltinPackage, error)

        // PackagesForFile returns the packages that this file belongs to, checked
        // in mode.
        PackagesForFile(ctx context.Context, uri span.URI, mode TypecheckMode) ([]Package, error)

        // PackageForFile returns a single package that this file belongs to,
        // checked in mode and filtered by the package policy.
        PackageForFile(ctx context.Context, uri span.URI, mode TypecheckMode, selectPackage PackageFilter) (Package, error)

        // GetActiveReverseDeps returns the active files belonging to the reverse
        // dependencies of this file's package, checked in TypecheckWorkspace mode.
        GetReverseDependencies(ctx context.Context, id string) ([]Package, error)

        // CachedImportPaths returns all the imported packages loaded in this
        // snapshot, indexed by their import path and checked in TypecheckWorkspace
        // mode.
        CachedImportPaths(ctx context.Context) (map[string]Package, error)

        // KnownPackages returns all the packages loaded in this snapshot, checked
        // in TypecheckWorkspace mode.
        KnownPackages(ctx context.Context) ([]Package, error)

        // WorkspacePackages returns the snapshot's top-level packages.
        WorkspacePackages(ctx context.Context) ([]Package, error)

        // WorkspaceDirectories returns any directory known by the view. For views
        // within a module, this is the module root and any replace targets.
        WorkspaceDirectories(ctx context.Context) []span.URI
}

// PackageFilter sets how a package is filtered out from a set of packages
// containing a given file.
type PackageFilter int

const (
        // NarrowestPackage picks the "narrowest" package for a given file.
        // By "narrowest" package, we mean the package with the fewest number of
        // files that includes the given file. This solves the problem of test
        // variants, as the test will have more files than the non-test package.
        NarrowestPackage PackageFilter = iota

        // WidestPackage returns the Package containing the most files.
        // This is useful for something like diagnostics, where we'd prefer to
        // offer diagnostics for as many files as possible.
        WidestPackage
)

// InvocationMode represents the goal of a particular go command invocation.
type InvocationMode int

const (
        // Normal is appropriate for commands that might be run by a user and don't
        // deliberately modify go.mod files, e.g. `go test`.
        Normal = iota
        // UpdateUserModFile is for commands that intend to update the user's real
        // go.mod file, e.g. `go mod tidy` in response to a user's request to tidy.
        UpdateUserModFile
        // WriteTemporaryModFile is for commands that need information from a
        // modified version of the user's go.mod file, e.g. `go mod tidy` used to
        // generate diagnostics.
        WriteTemporaryModFile
        // ForTypeChecking is for packages.Load.
        ForTypeChecking
)

// View represents a single workspace.
// This is the level at which we maintain configuration like working directory
// and build tags.
type View interface {
        // Name returns the name this view was constructed with.
        Name() string

        // Folder returns the folder with which this view was created.
        Folder() span.URI

        // BackgroundContext returns a context used for all background processing
        // on behalf of this view.
        BackgroundContext() context.Context

        // Shutdown closes this view, and detaches it from its session.
        Shutdown(ctx context.Context)

        // Options returns a copy of the Options for this view.
        Options() *Options

        // SetOptions sets the options of this view to new values.
        // Calling this may cause the view to be invalidated and a replacement view
        // added to the session. If so the new view will be returned, otherwise the
        // original one will be.
        SetOptions(context.Context, *Options) (View, error)

        // Snapshot returns the current snapshot for the view.
        Snapshot(ctx context.Context) (Snapshot, func())

        // Rebuild rebuilds the current view, replacing the original view in its session.
        Rebuild(ctx context.Context) (Snapshot, func(), error)

        // IsGoPrivatePath reports whether target is a private import path, as identified
        // by the GOPRIVATE environment variable.
        IsGoPrivatePath(path string) bool
}

// A FileSource maps uris to FileHandles. This abstraction exists both for
// testability, and so that algorithms can be run equally on session and
// snapshot files.
type FileSource interface {
        // GetFile returns the FileHandle for a given URI.
        GetFile(ctx context.Context, uri span.URI) (FileHandle, error)
}

type BuiltinPackage struct {
        Package    *ast.Package
        ParsedFile *ParsedGoFile
}

// A ParsedGoFile contains the results of parsing a Go file.
type ParsedGoFile struct {
        URI  span.URI
        Mode ParseMode
        File *ast.File
        Tok  *token.File
        // Source code used to build the AST. It may be different from the
        // actual content of the file if we have fixed the AST.
        Src      []byte
        Mapper   *protocol.ColumnMapper
        ParseErr error
}

// A ParsedModule contains the results of parsing a go.mod file.
type ParsedModule struct {
        File        *modfile.File
        Mapper      *protocol.ColumnMapper
        ParseErrors []Error
}

// A TidiedModule contains the results of running `go mod tidy` on a module.
type TidiedModule struct {
        // The parsed module, which is guaranteed to have parsed successfully.
        Parsed *ParsedModule
        // Diagnostics representing changes made by `go mod tidy`.
        Errors []Error
        // The bytes of the go.mod file after it was tidied.
        TidiedContent []byte
}

// Session represents a single connection from a client.
// This is the level at which things like open files are maintained on behalf
// of the client.
// A session may have many active views at any given time.
type Session interface {
        // NewView creates a new View, returning it and its first snapshot.
        NewView(ctx context.Context, name string, folder, tempWorkspaceDir span.URI, options *Options) (View, Snapshot, func(), error)

        // Cache returns the cache that created this session, for debugging only.
        Cache() interface{}

        // View returns a view with a matching name, if the session has one.
        View(name string) View

        // ViewOf returns a view corresponding to the given URI.
        ViewOf(uri span.URI) (View, error)

        // Views returns the set of active views built by this session.
        Views() []View

        // Shutdown the session and all views it has created.
        Shutdown(ctx context.Context)

        // GetFile returns a handle for the specified file.
        GetFile(ctx context.Context, uri span.URI) (FileHandle, error)

        // DidModifyFile reports a file modification to the session. It returns the
        // resulting snapshots, a guaranteed one per view.
        DidModifyFiles(ctx context.Context, changes []FileModification) (map[span.URI]View, map[View]Snapshot, []func(), []span.URI, error)

        // Overlays returns a slice of file overlays for the session.
        Overlays() []Overlay

        // Options returns a copy of the SessionOptions for this session.
        Options() *Options

        // SetOptions sets the options of this session to new values.
        SetOptions(*Options)
}

// Overlay is the type for a file held in memory on a session.
type Overlay interface {
        VersionedFileHandle

        // Saved returns whether this overlay has been saved to disk.
        Saved() bool
}

// FileModification represents a modification to a file.
type FileModification struct {
        URI    span.URI
        Action FileAction

        // OnDisk is true if a watched file is changed on disk.
        // If true, Version will be -1 and Text will be nil.
        OnDisk bool

        // Version will be -1 and Text will be nil when they are not supplied,
        // specifically on textDocument/didClose and for on-disk changes.
        Version float64
        Text    []byte

        // LanguageID is only sent from the language client on textDocument/didOpen.
        LanguageID string
}

type FileAction int

const (
        UnknownFileAction = FileAction(iota)
        Open
        Change
        Close
        Save
        Create
        Delete
        InvalidateMetadata
)

func (a FileAction) String() string {
        switch a {
        case Open:
                return "Open"
        case Change:
                return "Change"
        case Close:
                return "Close"
        case Save:
                return "Save"
        case Create:
                return "Create"
        case Delete:
                return "Delete"
        case InvalidateMetadata:
                return "InvalidateMetadata"
        default:
                return "Unknown"
        }
}

var ErrTmpModfileUnsupported = errors.New("-modfile is unsupported for this Go version")
var ErrNoModOnDisk = errors.New("go.mod file is not on disk")

func IsNonFatalGoModError(err error) bool {
        return err == ErrTmpModfileUnsupported || err == ErrNoModOnDisk
}

// ParseMode controls the content of the AST produced when parsing a source file.
type ParseMode int

const (
        // ParseHeader specifies that the main package declaration and imports are needed.
        // This is the mode used when attempting to examine the package graph structure.
        ParseHeader ParseMode = iota

        // ParseExported specifies that the public symbols are needed, but things like
        // private symbols and function bodies are not.
        // This mode is used for things where a package is being consumed only as a
        // dependency.
        ParseExported

        // ParseFull specifies the full AST is needed.
        // This is used for files of direct interest where the entire contents must
        // be considered.
        ParseFull
)

// TypecheckMode controls what kind of parsing should be done (see ParseMode)
// while type checking a package.
type TypecheckMode int

const (
        // Invalid default value.
        TypecheckUnknown TypecheckMode = iota
        // TypecheckFull means to use ParseFull.
        TypecheckFull
        // TypecheckWorkspace means to use ParseFull for workspace packages, and
        // ParseExported for others.
        TypecheckWorkspace
        // TypecheckAll means ParseFull for workspace packages, and both Full and
        // Exported for others. Only valid for some functions.
        TypecheckAll
)

type VersionedFileHandle interface {
        FileHandle
        Version() float64
        Session() string

        // LSPIdentity returns the version identity of a file.
        VersionedFileIdentity() VersionedFileIdentity
}

type VersionedFileIdentity struct {
        URI span.URI

        // SessionID is the ID of the LSP session.
        SessionID string

        // Version is the version of the file, as specified by the client. It should
        // only be set in combination with SessionID.
        Version float64
}

// FileHandle represents a handle to a specific version of a single file.
type FileHandle interface {
        URI() span.URI
        Kind() FileKind

        // FileIdentity returns a FileIdentity for the file, even if there was an
        // error reading it.
        FileIdentity() FileIdentity
        // Read reads the contents of a file.
        // If the file is not available, returns a nil slice and an error.
        Read() ([]byte, error)
}

// FileIdentity uniquely identifies a file at a version from a FileSystem.
type FileIdentity struct {
        URI span.URI

        // Identifier represents a unique identifier for the file's content.
        Hash string

        // Kind is the file's kind.
        Kind FileKind
}

func (id FileIdentity) String() string {
        return fmt.Sprintf("%s%s%s", id.URI, id.Hash, id.Kind)
}

// FileKind describes the kind of the file in question.
// It can be one of Go, mod, or sum.
type FileKind int

const (
        // UnknownKind is a file type we don't know about.
        UnknownKind = FileKind(iota)

        // Go is a normal go source file.
        Go
        // Mod is a go.mod file.
        Mod
        // Sum is a go.sum file.
        Sum
)

// Analyzer represents a go/analysis analyzer with some boolean properties
// that let the user know how to use the analyzer.
type Analyzer struct {
        Analyzer *analysis.Analyzer

        // Enabled reports whether the analyzer is enabled. This value can be
        // configured per-analysis in user settings. For staticcheck analyzers,
        // the value of the Staticcheck setting overrides this field.
        Enabled bool

        // Command is the name of the command used to invoke the suggested fixes
        // for the analyzer. It is non-nil if we expect this analyzer to provide
        // its fix separately from its diagnostics. That is, we should apply the
        // analyzer's suggested fixes through a Command, not a TextEdit.
        Command *Command

        // If this is true, then we can apply the suggested fixes
        // as part of a source.FixAll codeaction.
        HighConfidence bool

        // FixesError is only set for type-error analyzers.
        // It reports true if the message provided indicates an error that could be
        // fixed by the analyzer.
        FixesError func(msg string) bool
}

func (a Analyzer) IsEnabled(view View) bool {
        // Staticcheck analyzers can only be enabled when staticcheck is on.
        if _, ok := view.Options().StaticcheckAnalyzers[a.Analyzer.Name]; ok {
                if !view.Options().Staticcheck {
                        return false
                }
        }
        if enabled, ok := view.Options().Analyses[a.Analyzer.Name]; ok {
                return enabled
        }
        return a.Enabled
}

// Package represents a Go package that has been type-checked. It maintains
// only the relevant fields of a *go/packages.Package.
type Package interface {
        ID() string
        Name() string
        PkgPath() string
        CompiledGoFiles() []*ParsedGoFile
        File(uri span.URI) (*ParsedGoFile, error)
        GetSyntax() []*ast.File
        GetErrors() []*Error
        GetTypes() *types.Package
        GetTypesInfo() *types.Info
        GetTypesSizes() types.Sizes
        IsIllTyped() bool
        ForTest() string
        GetImport(pkgPath string) (Package, error)
        MissingDependencies() []string
        Imports() []Package
        Version() *module.Version
}

type ErrorList []*Error

func (err *ErrorList) Error() string {
        var b strings.Builder
        b.WriteString("source error list:")
        for _, e := range *err {
                b.WriteString(fmt.Sprintf("\n\t%s", e))
        }
        return b.String()
}

// An Error corresponds to an LSP Diagnostic.
// https://microsoft.github.io/language-server-protocol/specification#diagnostic
type Error struct {
        URI      span.URI
        Range    protocol.Range
        Kind     ErrorKind
        Message  string
        Category string // only used by analysis errors so far
        Related  []RelatedInformation

        // SuggestedFixes is used to generate quick fixes for a CodeAction request.
        // It isn't part of the Diagnostic type.
        SuggestedFixes []SuggestedFix
}

// GoModTidy is the source for a diagnostic computed by running `go mod tidy`.
const GoModTidy = "go mod tidy"

type ErrorKind int

const (
        UnknownError = ErrorKind(iota)
        ListError
        ParseError
        TypeError
        ModTidyError
        Analysis
)

func (e *Error) Error() string {
        return fmt.Sprintf("%s:%s: %s", e.URI, e.Range, e.Message)
}

var (
        PackagesLoadError = errors.New("packages.Load error")
)

// WorkspaceModuleVersion is the nonexistent pseudoversion suffix used in the
// construction of the workspace module. It is exported so that we can make
// sure not to show this version to end users in error messages, to avoid
// confusion.
// The major version is not included, as that depends on the module path.
const workspaceModuleVersion = ".0.0-goplsworkspace"

func IsWorkspaceModuleVersion(version string) bool {
        return strings.HasSuffix(version, workspaceModuleVersion)
}

func WorkspaceModuleVersion(majorVersion string) string {
        return majorVersion + workspaceModuleVersion
}