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Diffstat (limited to 'vendor/golang.org/x/tools/go/packages/packages.go')
| -rw-r--r-- | vendor/golang.org/x/tools/go/packages/packages.go | 1212 |
1 files changed, 1212 insertions, 0 deletions
diff --git a/vendor/golang.org/x/tools/go/packages/packages.go b/vendor/golang.org/x/tools/go/packages/packages.go new file mode 100644 index 0000000..04053f1 --- /dev/null +++ b/vendor/golang.org/x/tools/go/packages/packages.go @@ -0,0 +1,1212 @@ +// 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 packages + +// See doc.go for package documentation and implementation notes. + +import ( + "context" + "encoding/json" + "fmt" + "go/ast" + "go/parser" + "go/scanner" + "go/token" + "go/types" + "io/ioutil" + "log" + "os" + "path/filepath" + "strings" + "sync" + "time" + + "golang.org/x/tools/go/gcexportdata" + "golang.org/x/tools/internal/gocommand" + "golang.org/x/tools/internal/packagesinternal" + "golang.org/x/tools/internal/typesinternal" +) + +// A LoadMode controls the amount of detail to return when loading. +// The bits below can be combined to specify which fields should be +// filled in the result packages. +// The zero value is a special case, equivalent to combining +// the NeedName, NeedFiles, and NeedCompiledGoFiles bits. +// ID and Errors (if present) will always be filled. +// Load may return more information than requested. +type LoadMode int + +// TODO(matloob): When a V2 of go/packages is released, rename NeedExportsFile to +// NeedExportFile to make it consistent with the Package field it's adding. + +const ( + // NeedName adds Name and PkgPath. + NeedName LoadMode = 1 << iota + + // NeedFiles adds GoFiles and OtherFiles. + NeedFiles + + // NeedCompiledGoFiles adds CompiledGoFiles. + NeedCompiledGoFiles + + // NeedImports adds Imports. If NeedDeps is not set, the Imports field will contain + // "placeholder" Packages with only the ID set. + NeedImports + + // NeedDeps adds the fields requested by the LoadMode in the packages in Imports. + NeedDeps + + // NeedExportsFile adds ExportFile. + NeedExportsFile + + // NeedTypes adds Types, Fset, and IllTyped. + NeedTypes + + // NeedSyntax adds Syntax. + NeedSyntax + + // NeedTypesInfo adds TypesInfo. + NeedTypesInfo + + // NeedTypesSizes adds TypesSizes. + NeedTypesSizes + + // typecheckCgo enables full support for type checking cgo. Requires Go 1.15+. + // Modifies CompiledGoFiles and Types, and has no effect on its own. + typecheckCgo + + // NeedModule adds Module. + NeedModule +) + +const ( + // Deprecated: LoadFiles exists for historical compatibility + // and should not be used. Please directly specify the needed fields using the Need values. + LoadFiles = NeedName | NeedFiles | NeedCompiledGoFiles + + // Deprecated: LoadImports exists for historical compatibility + // and should not be used. Please directly specify the needed fields using the Need values. + LoadImports = LoadFiles | NeedImports + + // Deprecated: LoadTypes exists for historical compatibility + // and should not be used. Please directly specify the needed fields using the Need values. + LoadTypes = LoadImports | NeedTypes | NeedTypesSizes + + // Deprecated: LoadSyntax exists for historical compatibility + // and should not be used. Please directly specify the needed fields using the Need values. + LoadSyntax = LoadTypes | NeedSyntax | NeedTypesInfo + + // Deprecated: LoadAllSyntax exists for historical compatibility + // and should not be used. Please directly specify the needed fields using the Need values. + LoadAllSyntax = LoadSyntax | NeedDeps +) + +// A Config specifies details about how packages should be loaded. +// The zero value is a valid configuration. +// Calls to Load do not modify this struct. +type Config struct { + // Mode controls the level of information returned for each package. + Mode LoadMode + + // Context specifies the context for the load operation. + // If the context is cancelled, the loader may stop early + // and return an ErrCancelled error. + // If Context is nil, the load cannot be cancelled. + Context context.Context + + // Logf is the logger for the config. + // If the user provides a logger, debug logging is enabled. + // If the GOPACKAGESDEBUG environment variable is set to true, + // but the logger is nil, default to log.Printf. + Logf func(format string, args ...interface{}) + + // Dir is the directory in which to run the build system's query tool + // that provides information about the packages. + // If Dir is empty, the tool is run in the current directory. + Dir string + + // Env is the environment to use when invoking the build system's query tool. + // If Env is nil, the current environment is used. + // As in os/exec's Cmd, only the last value in the slice for + // each environment key is used. To specify the setting of only + // a few variables, append to the current environment, as in: + // + // opt.Env = append(os.Environ(), "GOOS=plan9", "GOARCH=386") + // + Env []string + + // gocmdRunner guards go command calls from concurrency errors. + gocmdRunner *gocommand.Runner + + // BuildFlags is a list of command-line flags to be passed through to + // the build system's query tool. + BuildFlags []string + + // Fset provides source position information for syntax trees and types. + // If Fset is nil, Load will use a new fileset, but preserve Fset's value. + Fset *token.FileSet + + // ParseFile is called to read and parse each file + // when preparing a package's type-checked syntax tree. + // It must be safe to call ParseFile simultaneously from multiple goroutines. + // If ParseFile is nil, the loader will uses parser.ParseFile. + // + // ParseFile should parse the source from src and use filename only for + // recording position information. + // + // An application may supply a custom implementation of ParseFile + // to change the effective file contents or the behavior of the parser, + // or to modify the syntax tree. For example, selectively eliminating + // unwanted function bodies can significantly accelerate type checking. + ParseFile func(fset *token.FileSet, filename string, src []byte) (*ast.File, error) + + // If Tests is set, the loader includes not just the packages + // matching a particular pattern but also any related test packages, + // including test-only variants of the package and the test executable. + // + // For example, when using the go command, loading "fmt" with Tests=true + // returns four packages, with IDs "fmt" (the standard package), + // "fmt [fmt.test]" (the package as compiled for the test), + // "fmt_test" (the test functions from source files in package fmt_test), + // and "fmt.test" (the test binary). + // + // In build systems with explicit names for tests, + // setting Tests may have no effect. + Tests bool + + // Overlay provides a mapping of absolute file paths to file contents. + // If the file with the given path already exists, the parser will use the + // alternative file contents provided by the map. + // + // Overlays provide incomplete support for when a given file doesn't + // already exist on disk. See the package doc above for more details. + Overlay map[string][]byte +} + +// driver is the type for functions that query the build system for the +// packages named by the patterns. +type driver func(cfg *Config, patterns ...string) (*driverResponse, error) + +// driverResponse contains the results for a driver query. +type driverResponse struct { + // NotHandled is returned if the request can't be handled by the current + // driver. If an external driver returns a response with NotHandled, the + // rest of the driverResponse is ignored, and go/packages will fallback + // to the next driver. If go/packages is extended in the future to support + // lists of multiple drivers, go/packages will fall back to the next driver. + NotHandled bool + + // Sizes, if not nil, is the types.Sizes to use when type checking. + Sizes *types.StdSizes + + // Roots is the set of package IDs that make up the root packages. + // We have to encode this separately because when we encode a single package + // we cannot know if it is one of the roots as that requires knowledge of the + // graph it is part of. + Roots []string `json:",omitempty"` + + // Packages is the full set of packages in the graph. + // The packages are not connected into a graph. + // The Imports if populated will be stubs that only have their ID set. + // Imports will be connected and then type and syntax information added in a + // later pass (see refine). + Packages []*Package +} + +// Load loads and returns the Go packages named by the given patterns. +// +// Config specifies loading options; +// nil behaves the same as an empty Config. +// +// Load returns an error if any of the patterns was invalid +// as defined by the underlying build system. +// It may return an empty list of packages without an error, +// for instance for an empty expansion of a valid wildcard. +// Errors associated with a particular package are recorded in the +// corresponding Package's Errors list, and do not cause Load to +// return an error. Clients may need to handle such errors before +// proceeding with further analysis. The PrintErrors function is +// provided for convenient display of all errors. +func Load(cfg *Config, patterns ...string) ([]*Package, error) { + l := newLoader(cfg) + response, err := defaultDriver(&l.Config, patterns...) + if err != nil { + return nil, err + } + l.sizes = response.Sizes + return l.refine(response.Roots, response.Packages...) +} + +// defaultDriver is a driver that implements go/packages' fallback behavior. +// It will try to request to an external driver, if one exists. If there's +// no external driver, or the driver returns a response with NotHandled set, +// defaultDriver will fall back to the go list driver. +func defaultDriver(cfg *Config, patterns ...string) (*driverResponse, error) { + driver := findExternalDriver(cfg) + if driver == nil { + driver = goListDriver + } + response, err := driver(cfg, patterns...) + if err != nil { + return response, err + } else if response.NotHandled { + return goListDriver(cfg, patterns...) + } + return response, nil +} + +// A Package describes a loaded Go package. +type Package struct { + // ID is a unique identifier for a package, + // in a syntax provided by the underlying build system. + // + // Because the syntax varies based on the build system, + // clients should treat IDs as opaque and not attempt to + // interpret them. + ID string + + // Name is the package name as it appears in the package source code. + Name string + + // PkgPath is the package path as used by the go/types package. + PkgPath string + + // Errors contains any errors encountered querying the metadata + // of the package, or while parsing or type-checking its files. + Errors []Error + + // GoFiles lists the absolute file paths of the package's Go source files. + GoFiles []string + + // CompiledGoFiles lists the absolute file paths of the package's source + // files that are suitable for type checking. + // This may differ from GoFiles if files are processed before compilation. + CompiledGoFiles []string + + // OtherFiles lists the absolute file paths of the package's non-Go source files, + // including assembly, C, C++, Fortran, Objective-C, SWIG, and so on. + OtherFiles []string + + // ExportFile is the absolute path to a file containing type + // information for the package as provided by the build system. + ExportFile string + + // Imports maps import paths appearing in the package's Go source files + // to corresponding loaded Packages. + Imports map[string]*Package + + // Types provides type information for the package. + // The NeedTypes LoadMode bit sets this field for packages matching the + // patterns; type information for dependencies may be missing or incomplete, + // unless NeedDeps and NeedImports are also set. + Types *types.Package + + // Fset provides position information for Types, TypesInfo, and Syntax. + // It is set only when Types is set. + Fset *token.FileSet + + // IllTyped indicates whether the package or any dependency contains errors. + // It is set only when Types is set. + IllTyped bool + + // Syntax is the package's syntax trees, for the files listed in CompiledGoFiles. + // + // The NeedSyntax LoadMode bit populates this field for packages matching the patterns. + // If NeedDeps and NeedImports are also set, this field will also be populated + // for dependencies. + Syntax []*ast.File + + // TypesInfo provides type information about the package's syntax trees. + // It is set only when Syntax is set. + TypesInfo *types.Info + + // TypesSizes provides the effective size function for types in TypesInfo. + TypesSizes types.Sizes + + // forTest is the package under test, if any. + forTest string + + // module is the module information for the package if it exists. + Module *Module +} + +// Module provides module information for a package. +type Module struct { + Path string // module path + Version string // module version + Replace *Module // replaced by this module + Time *time.Time // time version was created + Main bool // is this the main module? + Indirect bool // is this module only an indirect dependency of main module? + Dir string // directory holding files for this module, if any + GoMod string // path to go.mod file used when loading this module, if any + GoVersion string // go version used in module + Error *ModuleError // error loading module +} + +// ModuleError holds errors loading a module. +type ModuleError struct { + Err string // the error itself +} + +func init() { + packagesinternal.GetForTest = func(p interface{}) string { + return p.(*Package).forTest + } + packagesinternal.GetGoCmdRunner = func(config interface{}) *gocommand.Runner { + return config.(*Config).gocmdRunner + } + packagesinternal.SetGoCmdRunner = func(config interface{}, runner *gocommand.Runner) { + config.(*Config).gocmdRunner = runner + } + packagesinternal.TypecheckCgo = int(typecheckCgo) +} + +// An Error describes a problem with a package's metadata, syntax, or types. +type Error struct { + Pos string // "file:line:col" or "file:line" or "" or "-" + Msg string + Kind ErrorKind +} + +// ErrorKind describes the source of the error, allowing the user to +// differentiate between errors generated by the driver, the parser, or the +// type-checker. +type ErrorKind int + +const ( + UnknownError ErrorKind = iota + ListError + ParseError + TypeError +) + +func (err Error) Error() string { + pos := err.Pos + if pos == "" { + pos = "-" // like token.Position{}.String() + } + return pos + ": " + err.Msg +} + +// flatPackage is the JSON form of Package +// It drops all the type and syntax fields, and transforms the Imports +// +// TODO(adonovan): identify this struct with Package, effectively +// publishing the JSON protocol. +type flatPackage struct { + ID string + Name string `json:",omitempty"` + PkgPath string `json:",omitempty"` + Errors []Error `json:",omitempty"` + GoFiles []string `json:",omitempty"` + CompiledGoFiles []string `json:",omitempty"` + OtherFiles []string `json:",omitempty"` + ExportFile string `json:",omitempty"` + Imports map[string]string `json:",omitempty"` +} + +// MarshalJSON returns the Package in its JSON form. +// For the most part, the structure fields are written out unmodified, and +// the type and syntax fields are skipped. +// The imports are written out as just a map of path to package id. +// The errors are written using a custom type that tries to preserve the +// structure of error types we know about. +// +// This method exists to enable support for additional build systems. It is +// not intended for use by clients of the API and we may change the format. +func (p *Package) MarshalJSON() ([]byte, error) { + flat := &flatPackage{ + ID: p.ID, + Name: p.Name, + PkgPath: p.PkgPath, + Errors: p.Errors, + GoFiles: p.GoFiles, + CompiledGoFiles: p.CompiledGoFiles, + OtherFiles: p.OtherFiles, + ExportFile: p.ExportFile, + } + if len(p.Imports) > 0 { + flat.Imports = make(map[string]string, len(p.Imports)) + for path, ipkg := range p.Imports { + flat.Imports[path] = ipkg.ID + } + } + return json.Marshal(flat) +} + +// UnmarshalJSON reads in a Package from its JSON format. +// See MarshalJSON for details about the format accepted. +func (p *Package) UnmarshalJSON(b []byte) error { + flat := &flatPackage{} + if err := json.Unmarshal(b, &flat); err != nil { + return err + } + *p = Package{ + ID: flat.ID, + Name: flat.Name, + PkgPath: flat.PkgPath, + Errors: flat.Errors, + GoFiles: flat.GoFiles, + CompiledGoFiles: flat.CompiledGoFiles, + OtherFiles: flat.OtherFiles, + ExportFile: flat.ExportFile, + } + if len(flat.Imports) > 0 { + p.Imports = make(map[string]*Package, len(flat.Imports)) + for path, id := range flat.Imports { + p.Imports[path] = &Package{ID: id} + } + } + return nil +} + +func (p *Package) String() string { return p.ID } + +// loaderPackage augments Package with state used during the loading phase +type loaderPackage struct { + *Package + importErrors map[string]error // maps each bad import to its error + loadOnce sync.Once + color uint8 // for cycle detection + needsrc bool // load from source (Mode >= LoadTypes) + needtypes bool // type information is either requested or depended on + initial bool // package was matched by a pattern +} + +// loader holds the working state of a single call to load. +type loader struct { + pkgs map[string]*loaderPackage + Config + sizes types.Sizes + parseCache map[string]*parseValue + parseCacheMu sync.Mutex + exportMu sync.Mutex // enforces mutual exclusion of exportdata operations + + // Config.Mode contains the implied mode (see impliedLoadMode). + // Implied mode contains all the fields we need the data for. + // In requestedMode there are the actually requested fields. + // We'll zero them out before returning packages to the user. + // This makes it easier for us to get the conditions where + // we need certain modes right. + requestedMode LoadMode +} + +type parseValue struct { + f *ast.File + err error + ready chan struct{} +} + +func newLoader(cfg *Config) *loader { + ld := &loader{ + parseCache: map[string]*parseValue{}, + } + if cfg != nil { + ld.Config = *cfg + // If the user has provided a logger, use it. + ld.Config.Logf = cfg.Logf + } + if ld.Config.Logf == nil { + // If the GOPACKAGESDEBUG environment variable is set to true, + // but the user has not provided a logger, default to log.Printf. + if debug { + ld.Config.Logf = log.Printf + } else { + ld.Config.Logf = func(format string, args ...interface{}) {} + } + } + if ld.Config.Mode == 0 { + ld.Config.Mode = NeedName | NeedFiles | NeedCompiledGoFiles // Preserve zero behavior of Mode for backwards compatibility. + } + if ld.Config.Env == nil { + ld.Config.Env = os.Environ() + } + if ld.Config.gocmdRunner == nil { + ld.Config.gocmdRunner = &gocommand.Runner{} + } + if ld.Context == nil { + ld.Context = context.Background() + } + if ld.Dir == "" { + if dir, err := os.Getwd(); err == nil { + ld.Dir = dir + } + } + + // Save the actually requested fields. We'll zero them out before returning packages to the user. + ld.requestedMode = ld.Mode + ld.Mode = impliedLoadMode(ld.Mode) + + if ld.Mode&NeedTypes != 0 || ld.Mode&NeedSyntax != 0 { + if ld.Fset == nil { + ld.Fset = token.NewFileSet() + } + + // ParseFile is required even in LoadTypes mode + // because we load source if export data is missing. + if ld.ParseFile == nil { + ld.ParseFile = func(fset *token.FileSet, filename string, src []byte) (*ast.File, error) { + const mode = parser.AllErrors | parser.ParseComments + return parser.ParseFile(fset, filename, src, mode) + } + } + } + + return ld +} + +// refine connects the supplied packages into a graph and then adds type and +// and syntax information as requested by the LoadMode. +func (ld *loader) refine(roots []string, list ...*Package) ([]*Package, error) { + rootMap := make(map[string]int, len(roots)) + for i, root := range roots { + rootMap[root] = i + } + ld.pkgs = make(map[string]*loaderPackage) + // first pass, fixup and build the map and roots + var initial = make([]*loaderPackage, len(roots)) + for _, pkg := range list { + rootIndex := -1 + if i, found := rootMap[pkg.ID]; found { + rootIndex = i + } + + // Overlays can invalidate export data. + // TODO(matloob): make this check fine-grained based on dependencies on overlaid files + exportDataInvalid := len(ld.Overlay) > 0 || pkg.ExportFile == "" && pkg.PkgPath != "unsafe" + // This package needs type information if the caller requested types and the package is + // either a root, or it's a non-root and the user requested dependencies ... + needtypes := (ld.Mode&NeedTypes|NeedTypesInfo != 0 && (rootIndex >= 0 || ld.Mode&NeedDeps != 0)) + // This package needs source if the call requested source (or types info, which implies source) + // and the package is either a root, or itas a non- root and the user requested dependencies... + needsrc := ((ld.Mode&(NeedSyntax|NeedTypesInfo) != 0 && (rootIndex >= 0 || ld.Mode&NeedDeps != 0)) || + // ... or if we need types and the exportData is invalid. We fall back to (incompletely) + // typechecking packages from source if they fail to compile. + (ld.Mode&NeedTypes|NeedTypesInfo != 0 && exportDataInvalid)) && pkg.PkgPath != "unsafe" + lpkg := &loaderPackage{ + Package: pkg, + needtypes: needtypes, + needsrc: needsrc, + } + ld.pkgs[lpkg.ID] = lpkg + if rootIndex >= 0 { + initial[rootIndex] = lpkg + lpkg.initial = true + } + } + for i, root := range roots { + if initial[i] == nil { + return nil, fmt.Errorf("root package %v is missing", root) + } + } + + // Materialize the import graph. + + const ( + white = 0 // new + grey = 1 // in progress + black = 2 // complete + ) + + // visit traverses the import graph, depth-first, + // and materializes the graph as Packages.Imports. + // + // Valid imports are saved in the Packages.Import map. + // Invalid imports (cycles and missing nodes) are saved in the importErrors map. + // Thus, even in the presence of both kinds of errors, the Import graph remains a DAG. + // + // visit returns whether the package needs src or has a transitive + // dependency on a package that does. These are the only packages + // for which we load source code. + var stack []*loaderPackage + var visit func(lpkg *loaderPackage) bool + var srcPkgs []*loaderPackage + visit = func(lpkg *loaderPackage) bool { + switch lpkg.color { + case black: + return lpkg.needsrc + case grey: + panic("internal error: grey node") + } + lpkg.color = grey + stack = append(stack, lpkg) // push + stubs := lpkg.Imports // the structure form has only stubs with the ID in the Imports + // If NeedImports isn't set, the imports fields will all be zeroed out. + if ld.Mode&NeedImports != 0 { + lpkg.Imports = make(map[string]*Package, len(stubs)) + for importPath, ipkg := range stubs { + var importErr error + imp := ld.pkgs[ipkg.ID] + if imp == nil { + // (includes package "C" when DisableCgo) + importErr = fmt.Errorf("missing package: %q", ipkg.ID) + } else if imp.color == grey { + importErr = fmt.Errorf("import cycle: %s", stack) + } + if importErr != nil { + if lpkg.importErrors == nil { + lpkg.importErrors = make(map[string]error) + } + lpkg.importErrors[importPath] = importErr + continue + } + + if visit(imp) { + lpkg.needsrc = true + } + lpkg.Imports[importPath] = imp.Package + } + } + if lpkg.needsrc { + srcPkgs = append(srcPkgs, lpkg) + } + if ld.Mode&NeedTypesSizes != 0 { + lpkg.TypesSizes = ld.sizes + } + stack = stack[:len(stack)-1] // pop + lpkg.color = black + + return lpkg.needsrc + } + + if ld.Mode&NeedImports == 0 { + // We do this to drop the stub import packages that we are not even going to try to resolve. + for _, lpkg := range initial { + lpkg.Imports = nil + } + } else { + // For each initial package, create its import DAG. + for _, lpkg := range initial { + visit(lpkg) + } + } + if ld.Mode&NeedImports != 0 && ld.Mode&NeedTypes != 0 { + for _, lpkg := range srcPkgs { + // Complete type information is required for the + // immediate dependencies of each source package. + for _, ipkg := range lpkg.Imports { + imp := ld.pkgs[ipkg.ID] + imp.needtypes = true + } + } + } + // Load type data and syntax if needed, starting at + // the initial packages (roots of the import DAG). + if ld.Mode&NeedTypes != 0 || ld.Mode&NeedSyntax != 0 { + var wg sync.WaitGroup + for _, lpkg := range initial { + wg.Add(1) + go func(lpkg *loaderPackage) { + ld.loadRecursive(lpkg) + wg.Done() + }(lpkg) + } + wg.Wait() + } + + result := make([]*Package, len(initial)) + for i, lpkg := range initial { + result[i] = lpkg.Package + } + for i := range ld.pkgs { + // Clear all unrequested fields, for extra de-Hyrum-ization. + if ld.requestedMode&NeedName == 0 { + ld.pkgs[i].Name = "" + ld.pkgs[i].PkgPath = "" + } + if ld.requestedMode&NeedFiles == 0 { + ld.pkgs[i].GoFiles = nil + ld.pkgs[i].OtherFiles = nil + } + if ld.requestedMode&NeedCompiledGoFiles == 0 { + ld.pkgs[i].CompiledGoFiles = nil + } + if ld.requestedMode&NeedImports == 0 { + ld.pkgs[i].Imports = nil + } + if ld.requestedMode&NeedExportsFile == 0 { + ld.pkgs[i].ExportFile = "" + } + if ld.requestedMode&NeedTypes == 0 { + ld.pkgs[i].Types = nil + ld.pkgs[i].Fset = nil + ld.pkgs[i].IllTyped = false + } + if ld.requestedMode&NeedSyntax == 0 { + ld.pkgs[i].Syntax = nil + } + if ld.requestedMode&NeedTypesInfo == 0 { + ld.pkgs[i].TypesInfo = nil + } + if ld.requestedMode&NeedTypesSizes == 0 { + ld.pkgs[i].TypesSizes = nil + } + if ld.requestedMode&NeedModule == 0 { + ld.pkgs[i].Module = nil + } + } + + return result, nil +} + +// loadRecursive loads the specified package and its dependencies, +// recursively, in parallel, in topological order. +// It is atomic and idempotent. +// Precondition: ld.Mode&NeedTypes. +func (ld *loader) loadRecursive(lpkg *loaderPackage) { + lpkg.loadOnce.Do(func() { + // Load the direct dependencies, in parallel. + var wg sync.WaitGroup + for _, ipkg := range lpkg.Imports { + imp := ld.pkgs[ipkg.ID] + wg.Add(1) + go func(imp *loaderPackage) { + ld.loadRecursive(imp) + wg.Done() + }(imp) + } + wg.Wait() + ld.loadPackage(lpkg) + }) +} + +// loadPackage loads the specified package. +// It must be called only once per Package, +// after immediate dependencies are loaded. +// Precondition: ld.Mode & NeedTypes. +func (ld *loader) loadPackage(lpkg *loaderPackage) { + if lpkg.PkgPath == "unsafe" { + // Fill in the blanks to avoid surprises. + lpkg.Types = types.Unsafe + lpkg.Fset = ld.Fset + lpkg.Syntax = []*ast.File{} + lpkg.TypesInfo = new(types.Info) + lpkg.TypesSizes = ld.sizes + return + } + + // Call NewPackage directly with explicit name. + // This avoids skew between golist and go/types when the files' + // package declarations are inconsistent. + lpkg.Types = types.NewPackage(lpkg.PkgPath, lpkg.Name) + lpkg.Fset = ld.Fset + + // Subtle: we populate all Types fields with an empty Package + // before loading export data so that export data processing + // never has to create a types.Package for an indirect dependency, + // which would then require that such created packages be explicitly + // inserted back into the Import graph as a final step after export data loading. + // The Diamond test exercises this case. + if !lpkg.needtypes && !lpkg.needsrc { + return + } + if !lpkg.needsrc { + ld.loadFromExportData(lpkg) + return // not a source package, don't get syntax trees + } + + appendError := func(err error) { + // Convert various error types into the one true Error. + var errs []Error + switch err := err.(type) { + case Error: + // from driver + errs = append(errs, err) + + case *os.PathError: + // from parser + errs = append(errs, Error{ + Pos: err.Path + ":1", + Msg: err.Err.Error(), + Kind: ParseError, + }) + + case scanner.ErrorList: + // from parser + for _, err := range err { + errs = append(errs, Error{ + Pos: err.Pos.String(), + Msg: err.Msg, + Kind: ParseError, + }) + } + + case types.Error: + // from type checker + errs = append(errs, Error{ + Pos: err.Fset.Position(err.Pos).String(), + Msg: err.Msg, + Kind: TypeError, + }) + + default: + // unexpected impoverished error from parser? + errs = append(errs, Error{ + Pos: "-", + Msg: err.Error(), + Kind: UnknownError, + }) + + // If you see this error message, please file a bug. + log.Printf("internal error: error %q (%T) without position", err, err) + } + + lpkg.Errors = append(lpkg.Errors, errs...) + } + + if ld.Config.Mode&NeedTypes != 0 && len(lpkg.CompiledGoFiles) == 0 && lpkg.ExportFile != "" { + // The config requested loading sources and types, but sources are missing. + // Add an error to the package and fall back to loading from export data. + appendError(Error{"-", fmt.Sprintf("sources missing for package %s", lpkg.ID), ParseError}) + ld.loadFromExportData(lpkg) + return // can't get syntax trees for this package + } + + files, errs := ld.parseFiles(lpkg.CompiledGoFiles) + for _, err := range errs { + appendError(err) + } + + lpkg.Syntax = files + if ld.Config.Mode&NeedTypes == 0 { + return + } + + lpkg.TypesInfo = &types.Info{ + Types: make(map[ast.Expr]types.TypeAndValue), + Defs: make(map[*ast.Ident]types.Object), + Uses: make(map[*ast.Ident]types.Object), + Implicits: make(map[ast.Node]types.Object), + Scopes: make(map[ast.Node]*types.Scope), + Selections: make(map[*ast.SelectorExpr]*types.Selection), + } + lpkg.TypesSizes = ld.sizes + + importer := importerFunc(func(path string) (*types.Package, error) { + if path == "unsafe" { + return types.Unsafe, nil + } + + // The imports map is keyed by import path. + ipkg := lpkg.Imports[path] + if ipkg == nil { + if err := lpkg.importErrors[path]; err != nil { + return nil, err + } + // There was skew between the metadata and the + // import declarations, likely due to an edit + // race, or because the ParseFile feature was + // used to supply alternative file contents. + return nil, fmt.Errorf("no metadata for %s", path) + } + + if ipkg.Types != nil && ipkg.Types.Complete() { + return ipkg.Types, nil + } + log.Fatalf("internal error: package %q without types was imported from %q", path, lpkg) + panic("unreachable") + }) + + // type-check + tc := &types.Config{ + Importer: importer, + + // Type-check bodies of functions only in non-initial packages. + // Example: for import graph A->B->C and initial packages {A,C}, + // we can ignore function bodies in B. + IgnoreFuncBodies: ld.Mode&NeedDeps == 0 && !lpkg.initial, + + Error: appendError, + Sizes: ld.sizes, + } + if (ld.Mode & typecheckCgo) != 0 { + if !typesinternal.SetUsesCgo(tc) { + appendError(Error{ + Msg: "typecheckCgo requires Go 1.15+", + Kind: ListError, + }) + return + } + } + types.NewChecker(tc, ld.Fset, lpkg.Types, lpkg.TypesInfo).Files(lpkg.Syntax) + + lpkg.importErrors = nil // no longer needed + + // If !Cgo, the type-checker uses FakeImportC mode, so + // it doesn't invoke the importer for import "C", + // nor report an error for the import, + // or for any undefined C.f reference. + // We must detect this explicitly and correctly + // mark the package as IllTyped (by reporting an error). + // TODO(adonovan): if these errors are annoying, + // we could just set IllTyped quietly. + if tc.FakeImportC { + outer: + for _, f := range lpkg.Syntax { + for _, imp := range f.Imports { + if imp.Path.Value == `"C"` { + err := types.Error{Fset: ld.Fset, Pos: imp.Pos(), Msg: `import "C" ignored`} + appendError(err) + break outer + } + } + } + } + + // Record accumulated errors. + illTyped := len(lpkg.Errors) > 0 + if !illTyped { + for _, imp := range lpkg.Imports { + if imp.IllTyped { + illTyped = true + break + } + } + } + lpkg.IllTyped = illTyped +} + +// An importFunc is an implementation of the single-method +// types.Importer interface based on a function value. +type importerFunc func(path string) (*types.Package, error) + +func (f importerFunc) Import(path string) (*types.Package, error) { return f(path) } + +// We use a counting semaphore to limit +// the number of parallel I/O calls per process. +var ioLimit = make(chan bool, 20) + +func (ld *loader) parseFile(filename string) (*ast.File, error) { + ld.parseCacheMu.Lock() + v, ok := ld.parseCache[filename] + if ok { + // cache hit + ld.parseCacheMu.Unlock() + <-v.ready + } else { + // cache miss + v = &parseValue{ready: make(chan struct{})} + ld.parseCache[filename] = v + ld.parseCacheMu.Unlock() + + var src []byte + for f, contents := range ld.Config.Overlay { + if sameFile(f, filename) { + src = contents + } + } + var err error + if src == nil { + ioLimit <- true // wait + src, err = ioutil.ReadFile(filename) + <-ioLimit // signal + } + if err != nil { + v.err = err + } else { + v.f, v.err = ld.ParseFile(ld.Fset, filename, src) + } + + close(v.ready) + } + return v.f, v.err +} + +// parseFiles reads and parses the Go source files and returns the ASTs +// of the ones that could be at least partially parsed, along with a +// list of I/O and parse errors encountered. +// +// Because files are scanned in parallel, the token.Pos +// positions of the resulting ast.Files are not ordered. +// +func (ld *loader) parseFiles(filenames []string) ([]*ast.File, []error) { + var wg sync.WaitGroup + n := len(filenames) + parsed := make([]*ast.File, n) + errors := make([]error, n) + for i, file := range filenames { + if ld.Config.Context.Err() != nil { + parsed[i] = nil + errors[i] = ld.Config.Context.Err() + continue + } + wg.Add(1) + go func(i int, filename string) { + parsed[i], errors[i] = ld.parseFile(filename) + wg.Done() + }(i, file) + } + wg.Wait() + + // Eliminate nils, preserving order. + var o int + for _, f := range parsed { + if f != nil { + parsed[o] = f + o++ + } + } + parsed = parsed[:o] + + o = 0 + for _, err := range errors { + if err != nil { + errors[o] = err + o++ + } + } + errors = errors[:o] + + return parsed, errors +} + +// sameFile returns true if x and y have the same basename and denote +// the same file. +// +func sameFile(x, y string) bool { + if x == y { + // It could be the case that y doesn't exist. + // For instance, it may be an overlay file that + // hasn't been written to disk. To handle that case + // let x == y through. (We added the exact absolute path + // string to the CompiledGoFiles list, so the unwritten + // overlay case implies x==y.) + return true + } + if strings.EqualFold(filepath.Base(x), filepath.Base(y)) { // (optimisation) + if xi, err := os.Stat(x); err == nil { + if yi, err := os.Stat(y); err == nil { + return os.SameFile(xi, yi) + } + } + } + return false +} + +// loadFromExportData returns type information for the specified +// package, loading it from an export data file on the first request. +func (ld *loader) loadFromExportData(lpkg *loaderPackage) (*types.Package, error) { + if lpkg.PkgPath == "" { + log.Fatalf("internal error: Package %s has no PkgPath", lpkg) + } + + // Because gcexportdata.Read has the potential to create or + // modify the types.Package for each node in the transitive + // closure of dependencies of lpkg, all exportdata operations + // must be sequential. (Finer-grained locking would require + // changes to the gcexportdata API.) + // + // The exportMu lock guards the Package.Pkg field and the + // types.Package it points to, for each Package in the graph. + // + // Not all accesses to Package.Pkg need to be protected by exportMu: + // graph ordering ensures that direct dependencies of source + // packages are fully loaded before the importer reads their Pkg field. + ld.exportMu.Lock() + defer ld.exportMu.Unlock() + + if tpkg := lpkg.Types; tpkg != nil && tpkg.Complete() { + return tpkg, nil // cache hit + } + + lpkg.IllTyped = true // fail safe + + if lpkg.ExportFile == "" { + // Errors while building export data will have been printed to stderr. + return nil, fmt.Errorf("no export data file") + } + f, err := os.Open(lpkg.ExportFile) + if err != nil { + return nil, err + } + defer f.Close() + + // Read gc export data. + // + // We don't currently support gccgo export data because all + // underlying workspaces use the gc toolchain. (Even build + // systems that support gccgo don't use it for workspace + // queries.) + r, err := gcexportdata.NewReader(f) + if err != nil { + return nil, fmt.Errorf("reading %s: %v", lpkg.ExportFile, err) + } + + // Build the view. + // + // The gcexportdata machinery has no concept of package ID. + // It identifies packages by their PkgPath, which although not + // globally unique is unique within the scope of one invocation + // of the linker, type-checker, or gcexportdata. + // + // So, we must build a PkgPath-keyed view of the global + // (conceptually ID-keyed) cache of packages and pass it to + // gcexportdata. The view must contain every existing + // package that might possibly be mentioned by the + // current package---its transitive closure. + // + // In loadPackage, we unconditionally create a types.Package for + // each dependency so that export data loading does not + // create new ones. + // + // TODO(adonovan): it would be simpler and more efficient + // if the export data machinery invoked a callback to + // get-or-create a package instead of a map. + // + view := make(map[string]*types.Package) // view seen by gcexportdata + seen := make(map[*loaderPackage]bool) // all visited packages + var visit func(pkgs map[string]*Package) + visit = func(pkgs map[string]*Package) { + for _, p := range pkgs { + lpkg := ld.pkgs[p.ID] + if !seen[lpkg] { + seen[lpkg] = true + view[lpkg.PkgPath] = lpkg.Types + visit(lpkg.Imports) + } + } + } + visit(lpkg.Imports) + + viewLen := len(view) + 1 // adding the self package + // Parse the export data. + // (May modify incomplete packages in view but not create new ones.) + tpkg, err := gcexportdata.Read(r, ld.Fset, view, lpkg.PkgPath) + if err != nil { + return nil, fmt.Errorf("reading %s: %v", lpkg.ExportFile, err) + } + if viewLen != len(view) { + log.Fatalf("Unexpected package creation during export data loading") + } + + lpkg.Types = tpkg + lpkg.IllTyped = false + + return tpkg, nil +} + +// impliedLoadMode returns loadMode with its dependencies. +func impliedLoadMode(loadMode LoadMode) LoadMode { + if loadMode&NeedTypesInfo != 0 && loadMode&NeedImports == 0 { + // If NeedTypesInfo, go/packages needs to do typechecking itself so it can + // associate type info with the AST. To do so, we need the export data + // for dependencies, which means we need to ask for the direct dependencies. + // NeedImports is used to ask for the direct dependencies. + loadMode |= NeedImports + } + + if loadMode&NeedDeps != 0 && loadMode&NeedImports == 0 { + // With NeedDeps we need to load at least direct dependencies. + // NeedImports is used to ask for the direct dependencies. + loadMode |= NeedImports + } + + return loadMode +} + +func usesExportData(cfg *Config) bool { + return cfg.Mode&NeedExportsFile != 0 || cfg.Mode&NeedTypes != 0 && cfg.Mode&NeedDeps == 0 +} |