From 701d65734755b49d3c1409ace1c239c203242c0e Mon Sep 17 00:00:00 2001 From: Alan Donovan Date: Fri, 4 Nov 2016 17:23:57 -0400 Subject: [PATCH] tools: remove go1.8-tagged files Change-Id: Ib52b85e1c981b6fca55c472120371a0cd37d2dc9 Reviewed-on: https://go-review.googlesource.com/32816 Reviewed-by: Robert Griesemer --- cmd/stringer/stringer.go | 2 - cmd/stringer/stringer18.go | 638 ---------------------------------- go/ast/astutil/enclosing.go | 2 - go/ast/astutil/enclosing18.go | 629 --------------------------------- 4 files changed, 1271 deletions(-) delete mode 100644 cmd/stringer/stringer18.go delete mode 100644 go/ast/astutil/enclosing18.go diff --git a/cmd/stringer/stringer.go b/cmd/stringer/stringer.go index c581e16e..5d367757 100644 --- a/cmd/stringer/stringer.go +++ b/cmd/stringer/stringer.go @@ -2,8 +2,6 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. -// +build !go1.8 - // Stringer is a tool to automate the creation of methods that satisfy the fmt.Stringer // interface. Given the name of a (signed or unsigned) integer type T that has constants // defined, stringer will create a new self-contained Go source file implementing diff --git a/cmd/stringer/stringer18.go b/cmd/stringer/stringer18.go deleted file mode 100644 index 1b0dfbba..00000000 --- a/cmd/stringer/stringer18.go +++ /dev/null @@ -1,638 +0,0 @@ -// Copyright 2014 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. - -// +build go1.8 - -// Stringer is a tool to automate the creation of methods that satisfy the fmt.Stringer -// interface. Given the name of a (signed or unsigned) integer type T that has constants -// defined, stringer will create a new self-contained Go source file implementing -// func (t T) String() string -// The file is created in the same package and directory as the package that defines T. -// It has helpful defaults designed for use with go generate. -// -// Stringer works best with constants that are consecutive values such as created using iota, -// but creates good code regardless. In the future it might also provide custom support for -// constant sets that are bit patterns. -// -// For example, given this snippet, -// -// package painkiller -// -// type Pill int -// -// const ( -// Placebo Pill = iota -// Aspirin -// Ibuprofen -// Paracetamol -// Acetaminophen = Paracetamol -// ) -// -// running this command -// -// stringer -type=Pill -// -// in the same directory will create the file pill_string.go, in package painkiller, -// containing a definition of -// -// func (Pill) String() string -// -// That method will translate the value of a Pill constant to the string representation -// of the respective constant name, so that the call fmt.Print(painkiller.Aspirin) will -// print the string "Aspirin". -// -// Typically this process would be run using go generate, like this: -// -// //go:generate stringer -type=Pill -// -// If multiple constants have the same value, the lexically first matching name will -// be used (in the example, Acetaminophen will print as "Paracetamol"). -// -// With no arguments, it processes the package in the current directory. -// Otherwise, the arguments must name a single directory holding a Go package -// or a set of Go source files that represent a single Go package. -// -// The -type flag accepts a comma-separated list of types so a single run can -// generate methods for multiple types. The default output file is t_string.go, -// where t is the lower-cased name of the first type listed. It can be overridden -// with the -output flag. -// -package main // import "golang.org/x/tools/cmd/stringer" - -import ( - "bytes" - "flag" - "fmt" - "go/ast" - "go/build" - exact "go/constant" - "go/format" - "go/importer" - "go/parser" - "go/token" - "go/types" - "io/ioutil" - "log" - "os" - "path/filepath" - "sort" - "strings" -) - -var ( - typeNames = flag.String("type", "", "comma-separated list of type names; must be set") - output = flag.String("output", "", "output file name; default srcdir/_string.go") -) - -// Usage is a replacement usage function for the flags package. -func Usage() { - fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0]) - fmt.Fprintf(os.Stderr, "\tstringer [flags] -type T [directory]\n") - fmt.Fprintf(os.Stderr, "\tstringer [flags] -type T files... # Must be a single package\n") - fmt.Fprintf(os.Stderr, "For more information, see:\n") - fmt.Fprintf(os.Stderr, "\thttp://godoc.org/golang.org/x/tools/cmd/stringer\n") - fmt.Fprintf(os.Stderr, "Flags:\n") - flag.PrintDefaults() -} - -func main() { - log.SetFlags(0) - log.SetPrefix("stringer: ") - flag.Usage = Usage - flag.Parse() - if len(*typeNames) == 0 { - flag.Usage() - os.Exit(2) - } - types := strings.Split(*typeNames, ",") - - // We accept either one directory or a list of files. Which do we have? - args := flag.Args() - if len(args) == 0 { - // Default: process whole package in current directory. - args = []string{"."} - } - - // Parse the package once. - var ( - dir string - g Generator - ) - if len(args) == 1 && isDirectory(args[0]) { - dir = args[0] - g.parsePackageDir(args[0]) - } else { - dir = filepath.Dir(args[0]) - g.parsePackageFiles(args) - } - - // Print the header and package clause. - g.Printf("// Code generated by \"stringer %s\"; DO NOT EDIT\n", strings.Join(os.Args[1:], " ")) - g.Printf("\n") - g.Printf("package %s", g.pkg.name) - g.Printf("\n") - g.Printf("import \"fmt\"\n") // Used by all methods. - - // Run generate for each type. - for _, typeName := range types { - g.generate(typeName) - } - - // Format the output. - src := g.format() - - // Write to file. - outputName := *output - if outputName == "" { - baseName := fmt.Sprintf("%s_string.go", types[0]) - outputName = filepath.Join(dir, strings.ToLower(baseName)) - } - err := ioutil.WriteFile(outputName, src, 0644) - if err != nil { - log.Fatalf("writing output: %s", err) - } -} - -// isDirectory reports whether the named file is a directory. -func isDirectory(name string) bool { - info, err := os.Stat(name) - if err != nil { - log.Fatal(err) - } - return info.IsDir() -} - -// Generator holds the state of the analysis. Primarily used to buffer -// the output for format.Source. -type Generator struct { - buf bytes.Buffer // Accumulated output. - pkg *Package // Package we are scanning. -} - -func (g *Generator) Printf(format string, args ...interface{}) { - fmt.Fprintf(&g.buf, format, args...) -} - -// File holds a single parsed file and associated data. -type File struct { - pkg *Package // Package to which this file belongs. - file *ast.File // Parsed AST. - // These fields are reset for each type being generated. - typeName string // Name of the constant type. - values []Value // Accumulator for constant values of that type. -} - -type Package struct { - dir string - name string - defs map[*ast.Ident]types.Object - files []*File - typesPkg *types.Package -} - -// parsePackageDir parses the package residing in the directory. -func (g *Generator) parsePackageDir(directory string) { - pkg, err := build.Default.ImportDir(directory, 0) - if err != nil { - log.Fatalf("cannot process directory %s: %s", directory, err) - } - var names []string - names = append(names, pkg.GoFiles...) - names = append(names, pkg.CgoFiles...) - // TODO: Need to think about constants in test files. Maybe write type_string_test.go - // in a separate pass? For later. - // names = append(names, pkg.TestGoFiles...) // These are also in the "foo" package. - names = append(names, pkg.SFiles...) - names = prefixDirectory(directory, names) - g.parsePackage(directory, names, nil) -} - -// parsePackageFiles parses the package occupying the named files. -func (g *Generator) parsePackageFiles(names []string) { - g.parsePackage(".", names, nil) -} - -// prefixDirectory places the directory name on the beginning of each name in the list. -func prefixDirectory(directory string, names []string) []string { - if directory == "." { - return names - } - ret := make([]string, len(names)) - for i, name := range names { - ret[i] = filepath.Join(directory, name) - } - return ret -} - -// parsePackage analyzes the single package constructed from the named files. -// If text is non-nil, it is a string to be used instead of the content of the file, -// to be used for testing. parsePackage exits if there is an error. -func (g *Generator) parsePackage(directory string, names []string, text interface{}) { - var files []*File - var astFiles []*ast.File - g.pkg = new(Package) - fs := token.NewFileSet() - for _, name := range names { - if !strings.HasSuffix(name, ".go") { - continue - } - parsedFile, err := parser.ParseFile(fs, name, text, 0) - if err != nil { - log.Fatalf("parsing package: %s: %s", name, err) - } - astFiles = append(astFiles, parsedFile) - files = append(files, &File{ - file: parsedFile, - pkg: g.pkg, - }) - } - if len(astFiles) == 0 { - log.Fatalf("%s: no buildable Go files", directory) - } - g.pkg.name = astFiles[0].Name.Name - g.pkg.files = files - g.pkg.dir = directory - // Type check the package. - g.pkg.check(fs, astFiles) -} - -// check type-checks the package. The package must be OK to proceed. -func (pkg *Package) check(fs *token.FileSet, astFiles []*ast.File) { - pkg.defs = make(map[*ast.Ident]types.Object) - config := types.Config{Importer: importer.Default(), FakeImportC: true} - info := &types.Info{ - Defs: pkg.defs, - } - typesPkg, err := config.Check(pkg.dir, fs, astFiles, info) - if err != nil { - log.Fatalf("checking package: %s", err) - } - pkg.typesPkg = typesPkg -} - -// generate produces the String method for the named type. -func (g *Generator) generate(typeName string) { - values := make([]Value, 0, 100) - for _, file := range g.pkg.files { - // Set the state for this run of the walker. - file.typeName = typeName - file.values = nil - if file.file != nil { - ast.Inspect(file.file, file.genDecl) - values = append(values, file.values...) - } - } - - if len(values) == 0 { - log.Fatalf("no values defined for type %s", typeName) - } - runs := splitIntoRuns(values) - // The decision of which pattern to use depends on the number of - // runs in the numbers. If there's only one, it's easy. For more than - // one, there's a tradeoff between complexity and size of the data - // and code vs. the simplicity of a map. A map takes more space, - // but so does the code. The decision here (crossover at 10) is - // arbitrary, but considers that for large numbers of runs the cost - // of the linear scan in the switch might become important, and - // rather than use yet another algorithm such as binary search, - // we punt and use a map. In any case, the likelihood of a map - // being necessary for any realistic example other than bitmasks - // is very low. And bitmasks probably deserve their own analysis, - // to be done some other day. - switch { - case len(runs) == 1: - g.buildOneRun(runs, typeName) - case len(runs) <= 10: - g.buildMultipleRuns(runs, typeName) - default: - g.buildMap(runs, typeName) - } -} - -// splitIntoRuns breaks the values into runs of contiguous sequences. -// For example, given 1,2,3,5,6,7 it returns {1,2,3},{5,6,7}. -// The input slice is known to be non-empty. -func splitIntoRuns(values []Value) [][]Value { - // We use stable sort so the lexically first name is chosen for equal elements. - sort.Stable(byValue(values)) - // Remove duplicates. Stable sort has put the one we want to print first, - // so use that one. The String method won't care about which named constant - // was the argument, so the first name for the given value is the only one to keep. - // We need to do this because identical values would cause the switch or map - // to fail to compile. - j := 1 - for i := 1; i < len(values); i++ { - if values[i].value != values[i-1].value { - values[j] = values[i] - j++ - } - } - values = values[:j] - runs := make([][]Value, 0, 10) - for len(values) > 0 { - // One contiguous sequence per outer loop. - i := 1 - for i < len(values) && values[i].value == values[i-1].value+1 { - i++ - } - runs = append(runs, values[:i]) - values = values[i:] - } - return runs -} - -// format returns the gofmt-ed contents of the Generator's buffer. -func (g *Generator) format() []byte { - src, err := format.Source(g.buf.Bytes()) - if err != nil { - // Should never happen, but can arise when developing this code. - // The user can compile the output to see the error. - log.Printf("warning: internal error: invalid Go generated: %s", err) - log.Printf("warning: compile the package to analyze the error") - return g.buf.Bytes() - } - return src -} - -// Value represents a declared constant. -type Value struct { - name string // The name of the constant. - // The value is stored as a bit pattern alone. The boolean tells us - // whether to interpret it as an int64 or a uint64; the only place - // this matters is when sorting. - // Much of the time the str field is all we need; it is printed - // by Value.String. - value uint64 // Will be converted to int64 when needed. - signed bool // Whether the constant is a signed type. - str string // The string representation given by the "go/exact" package. -} - -func (v *Value) String() string { - return v.str -} - -// byValue lets us sort the constants into increasing order. -// We take care in the Less method to sort in signed or unsigned order, -// as appropriate. -type byValue []Value - -func (b byValue) Len() int { return len(b) } -func (b byValue) Swap(i, j int) { b[i], b[j] = b[j], b[i] } -func (b byValue) Less(i, j int) bool { - if b[i].signed { - return int64(b[i].value) < int64(b[j].value) - } - return b[i].value < b[j].value -} - -// genDecl processes one declaration clause. -func (f *File) genDecl(node ast.Node) bool { - decl, ok := node.(*ast.GenDecl) - if !ok || decl.Tok != token.CONST { - // We only care about const declarations. - return true - } - // The name of the type of the constants we are declaring. - // Can change if this is a multi-element declaration. - typ := "" - // Loop over the elements of the declaration. Each element is a ValueSpec: - // a list of names possibly followed by a type, possibly followed by values. - // If the type and value are both missing, we carry down the type (and value, - // but the "go/types" package takes care of that). - for _, spec := range decl.Specs { - vspec := spec.(*ast.ValueSpec) // Guaranteed to succeed as this is CONST. - if vspec.Type == nil && len(vspec.Values) > 0 { - // "X = 1". With no type but a value, the constant is untyped. - // Skip this vspec and reset the remembered type. - typ = "" - continue - } - if vspec.Type != nil { - // "X T". We have a type. Remember it. - ident, ok := vspec.Type.(*ast.Ident) - if !ok { - continue - } - typ = ident.Name - } - if typ != f.typeName { - // This is not the type we're looking for. - continue - } - // We now have a list of names (from one line of source code) all being - // declared with the desired type. - // Grab their names and actual values and store them in f.values. - for _, name := range vspec.Names { - if name.Name == "_" { - continue - } - // This dance lets the type checker find the values for us. It's a - // bit tricky: look up the object declared by the name, find its - // types.Const, and extract its value. - obj, ok := f.pkg.defs[name] - if !ok { - log.Fatalf("no value for constant %s", name) - } - info := obj.Type().Underlying().(*types.Basic).Info() - if info&types.IsInteger == 0 { - log.Fatalf("can't handle non-integer constant type %s", typ) - } - value := obj.(*types.Const).Val() // Guaranteed to succeed as this is CONST. - if value.Kind() != exact.Int { - log.Fatalf("can't happen: constant is not an integer %s", name) - } - i64, isInt := exact.Int64Val(value) - u64, isUint := exact.Uint64Val(value) - if !isInt && !isUint { - log.Fatalf("internal error: value of %s is not an integer: %s", name, value.String()) - } - if !isInt { - u64 = uint64(i64) - } - v := Value{ - name: name.Name, - value: u64, - signed: info&types.IsUnsigned == 0, - str: value.String(), - } - f.values = append(f.values, v) - } - } - return false -} - -// Helpers - -// usize returns the number of bits of the smallest unsigned integer -// type that will hold n. Used to create the smallest possible slice of -// integers to use as indexes into the concatenated strings. -func usize(n int) int { - switch { - case n < 1<<8: - return 8 - case n < 1<<16: - return 16 - default: - // 2^32 is enough constants for anyone. - return 32 - } -} - -// declareIndexAndNameVars declares the index slices and concatenated names -// strings representing the runs of values. -func (g *Generator) declareIndexAndNameVars(runs [][]Value, typeName string) { - var indexes, names []string - for i, run := range runs { - index, name := g.createIndexAndNameDecl(run, typeName, fmt.Sprintf("_%d", i)) - indexes = append(indexes, index) - names = append(names, name) - } - g.Printf("const (\n") - for _, name := range names { - g.Printf("\t%s\n", name) - } - g.Printf(")\n\n") - g.Printf("var (") - for _, index := range indexes { - g.Printf("\t%s\n", index) - } - g.Printf(")\n\n") -} - -// declareIndexAndNameVar is the single-run version of declareIndexAndNameVars -func (g *Generator) declareIndexAndNameVar(run []Value, typeName string) { - index, name := g.createIndexAndNameDecl(run, typeName, "") - g.Printf("const %s\n", name) - g.Printf("var %s\n", index) -} - -// createIndexAndNameDecl returns the pair of declarations for the run. The caller will add "const" and "var". -func (g *Generator) createIndexAndNameDecl(run []Value, typeName string, suffix string) (string, string) { - b := new(bytes.Buffer) - indexes := make([]int, len(run)) - for i := range run { - b.WriteString(run[i].name) - indexes[i] = b.Len() - } - nameConst := fmt.Sprintf("_%s_name%s = %q", typeName, suffix, b.String()) - nameLen := b.Len() - b.Reset() - fmt.Fprintf(b, "_%s_index%s = [...]uint%d{0, ", typeName, suffix, usize(nameLen)) - for i, v := range indexes { - if i > 0 { - fmt.Fprintf(b, ", ") - } - fmt.Fprintf(b, "%d", v) - } - fmt.Fprintf(b, "}") - return b.String(), nameConst -} - -// declareNameVars declares the concatenated names string representing all the values in the runs. -func (g *Generator) declareNameVars(runs [][]Value, typeName string, suffix string) { - g.Printf("const _%s_name%s = \"", typeName, suffix) - for _, run := range runs { - for i := range run { - g.Printf("%s", run[i].name) - } - } - g.Printf("\"\n") -} - -// buildOneRun generates the variables and String method for a single run of contiguous values. -func (g *Generator) buildOneRun(runs [][]Value, typeName string) { - values := runs[0] - g.Printf("\n") - g.declareIndexAndNameVar(values, typeName) - // The generated code is simple enough to write as a Printf format. - lessThanZero := "" - if values[0].signed { - lessThanZero = "i < 0 || " - } - if values[0].value == 0 { // Signed or unsigned, 0 is still 0. - g.Printf(stringOneRun, typeName, usize(len(values)), lessThanZero) - } else { - g.Printf(stringOneRunWithOffset, typeName, values[0].String(), usize(len(values)), lessThanZero) - } -} - -// Arguments to format are: -// [1]: type name -// [2]: size of index element (8 for uint8 etc.) -// [3]: less than zero check (for signed types) -const stringOneRun = `func (i %[1]s) String() string { - if %[3]si >= %[1]s(len(_%[1]s_index)-1) { - return fmt.Sprintf("%[1]s(%%d)", i) - } - return _%[1]s_name[_%[1]s_index[i]:_%[1]s_index[i+1]] -} -` - -// Arguments to format are: -// [1]: type name -// [2]: lowest defined value for type, as a string -// [3]: size of index element (8 for uint8 etc.) -// [4]: less than zero check (for signed types) -/* - */ -const stringOneRunWithOffset = `func (i %[1]s) String() string { - i -= %[2]s - if %[4]si >= %[1]s(len(_%[1]s_index)-1) { - return fmt.Sprintf("%[1]s(%%d)", i + %[2]s) - } - return _%[1]s_name[_%[1]s_index[i] : _%[1]s_index[i+1]] -} -` - -// buildMultipleRuns generates the variables and String method for multiple runs of contiguous values. -// For this pattern, a single Printf format won't do. -func (g *Generator) buildMultipleRuns(runs [][]Value, typeName string) { - g.Printf("\n") - g.declareIndexAndNameVars(runs, typeName) - g.Printf("func (i %s) String() string {\n", typeName) - g.Printf("\tswitch {\n") - for i, values := range runs { - if len(values) == 1 { - g.Printf("\tcase i == %s:\n", &values[0]) - g.Printf("\t\treturn _%s_name_%d\n", typeName, i) - continue - } - g.Printf("\tcase %s <= i && i <= %s:\n", &values[0], &values[len(values)-1]) - if values[0].value != 0 { - g.Printf("\t\ti -= %s\n", &values[0]) - } - g.Printf("\t\treturn _%s_name_%d[_%s_index_%d[i]:_%s_index_%d[i+1]]\n", - typeName, i, typeName, i, typeName, i) - } - g.Printf("\tdefault:\n") - g.Printf("\t\treturn fmt.Sprintf(\"%s(%%d)\", i)\n", typeName) - g.Printf("\t}\n") - g.Printf("}\n") -} - -// buildMap handles the case where the space is so sparse a map is a reasonable fallback. -// It's a rare situation but has simple code. -func (g *Generator) buildMap(runs [][]Value, typeName string) { - g.Printf("\n") - g.declareNameVars(runs, typeName, "") - g.Printf("\nvar _%s_map = map[%s]string{\n", typeName, typeName) - n := 0 - for _, values := range runs { - for _, value := range values { - g.Printf("\t%s: _%s_name[%d:%d],\n", &value, typeName, n, n+len(value.name)) - n += len(value.name) - } - } - g.Printf("}\n\n") - g.Printf(stringMap, typeName) -} - -// Argument to format is the type name. -const stringMap = `func (i %[1]s) String() string { - if str, ok := _%[1]s_map[i]; ok { - return str - } - return fmt.Sprintf("%[1]s(%%d)", i) -} -` diff --git a/go/ast/astutil/enclosing.go b/go/ast/astutil/enclosing.go index 94dff19c..6b7052b8 100644 --- a/go/ast/astutil/enclosing.go +++ b/go/ast/astutil/enclosing.go @@ -2,8 +2,6 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. -// +build !go1.8 - package astutil // This file defines utilities for working with source positions. diff --git a/go/ast/astutil/enclosing18.go b/go/ast/astutil/enclosing18.go deleted file mode 100644 index af897cb0..00000000 --- a/go/ast/astutil/enclosing18.go +++ /dev/null @@ -1,629 +0,0 @@ -// Copyright 2013 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. - -// +build go1.8 - -package astutil - -// This file defines utilities for working with source positions. - -import ( - "fmt" - "go/ast" - "go/token" - "sort" -) - -// PathEnclosingInterval returns the node that encloses the source -// interval [start, end), and all its ancestors up to the AST root. -// -// The definition of "enclosing" used by this function considers -// additional whitespace abutting a node to be enclosed by it. -// In this example: -// -// z := x + y // add them -// <-A-> -// <----B-----> -// -// the ast.BinaryExpr(+) node is considered to enclose interval B -// even though its [Pos()..End()) is actually only interval A. -// This behaviour makes user interfaces more tolerant of imperfect -// input. -// -// This function treats tokens as nodes, though they are not included -// in the result. e.g. PathEnclosingInterval("+") returns the -// enclosing ast.BinaryExpr("x + y"). -// -// If start==end, the 1-char interval following start is used instead. -// -// The 'exact' result is true if the interval contains only path[0] -// and perhaps some adjacent whitespace. It is false if the interval -// overlaps multiple children of path[0], or if it contains only -// interior whitespace of path[0]. -// In this example: -// -// z := x + y // add them -// <--C--> <---E--> -// ^ -// D -// -// intervals C, D and E are inexact. C is contained by the -// z-assignment statement, because it spans three of its children (:=, -// x, +). So too is the 1-char interval D, because it contains only -// interior whitespace of the assignment. E is considered interior -// whitespace of the BlockStmt containing the assignment. -// -// Precondition: [start, end) both lie within the same file as root. -// TODO(adonovan): return (nil, false) in this case and remove precond. -// Requires FileSet; see loader.tokenFileContainsPos. -// -// Postcondition: path is never nil; it always contains at least 'root'. -// -func PathEnclosingInterval(root *ast.File, start, end token.Pos) (path []ast.Node, exact bool) { - // fmt.Printf("EnclosingInterval %d %d\n", start, end) // debugging - - // Precondition: node.[Pos..End) and adjoining whitespace contain [start, end). - var visit func(node ast.Node) bool - visit = func(node ast.Node) bool { - path = append(path, node) - - nodePos := node.Pos() - nodeEnd := node.End() - - // fmt.Printf("visit(%T, %d, %d)\n", node, nodePos, nodeEnd) // debugging - - // Intersect [start, end) with interval of node. - if start < nodePos { - start = nodePos - } - if end > nodeEnd { - end = nodeEnd - } - - // Find sole child that contains [start, end). - children := childrenOf(node) - l := len(children) - for i, child := range children { - // [childPos, childEnd) is unaugmented interval of child. - childPos := child.Pos() - childEnd := child.End() - - // [augPos, augEnd) is whitespace-augmented interval of child. - augPos := childPos - augEnd := childEnd - if i > 0 { - augPos = children[i-1].End() // start of preceding whitespace - } - if i < l-1 { - nextChildPos := children[i+1].Pos() - // Does [start, end) lie between child and next child? - if start >= augEnd && end <= nextChildPos { - return false // inexact match - } - augEnd = nextChildPos // end of following whitespace - } - - // fmt.Printf("\tchild %d: [%d..%d)\tcontains interval [%d..%d)?\n", - // i, augPos, augEnd, start, end) // debugging - - // Does augmented child strictly contain [start, end)? - if augPos <= start && end <= augEnd { - _, isToken := child.(tokenNode) - return isToken || visit(child) - } - - // Does [start, end) overlap multiple children? - // i.e. left-augmented child contains start - // but LR-augmented child does not contain end. - if start < childEnd && end > augEnd { - break - } - } - - // No single child contained [start, end), - // so node is the result. Is it exact? - - // (It's tempting to put this condition before the - // child loop, but it gives the wrong result in the - // case where a node (e.g. ExprStmt) and its sole - // child have equal intervals.) - if start == nodePos && end == nodeEnd { - return true // exact match - } - - return false // inexact: overlaps multiple children - } - - if start > end { - start, end = end, start - } - - if start < root.End() && end > root.Pos() { - if start == end { - end = start + 1 // empty interval => interval of size 1 - } - exact = visit(root) - - // Reverse the path: - for i, l := 0, len(path); i < l/2; i++ { - path[i], path[l-1-i] = path[l-1-i], path[i] - } - } else { - // Selection lies within whitespace preceding the - // first (or following the last) declaration in the file. - // The result nonetheless always includes the ast.File. - path = append(path, root) - } - - return -} - -// tokenNode is a dummy implementation of ast.Node for a single token. -// They are used transiently by PathEnclosingInterval but never escape -// this package. -// -type tokenNode struct { - pos token.Pos - end token.Pos -} - -func (n tokenNode) Pos() token.Pos { - return n.pos -} - -func (n tokenNode) End() token.Pos { - return n.end -} - -func tok(pos token.Pos, len int) ast.Node { - return tokenNode{pos, pos + token.Pos(len)} -} - -// childrenOf returns the direct non-nil children of ast.Node n. -// It may include fake ast.Node implementations for bare tokens. -// it is not safe to call (e.g.) ast.Walk on such nodes. -// -func childrenOf(n ast.Node) []ast.Node { - var children []ast.Node - - // First add nodes for all true subtrees. - ast.Inspect(n, func(node ast.Node) bool { - if node == n { // push n - return true // recur - } - if node != nil { // push child - children = append(children, node) - } - return false // no recursion - }) - - // Then add fake Nodes for bare tokens. - switch n := n.(type) { - case *ast.ArrayType: - children = append(children, - tok(n.Lbrack, len("[")), - tok(n.Elt.End(), len("]"))) - - case *ast.AssignStmt: - children = append(children, - tok(n.TokPos, len(n.Tok.String()))) - - case *ast.BasicLit: - children = append(children, - tok(n.ValuePos, len(n.Value))) - - case *ast.BinaryExpr: - children = append(children, tok(n.OpPos, len(n.Op.String()))) - - case *ast.BlockStmt: - children = append(children, - tok(n.Lbrace, len("{")), - tok(n.Rbrace, len("}"))) - - case *ast.BranchStmt: - children = append(children, - tok(n.TokPos, len(n.Tok.String()))) - - case *ast.CallExpr: - children = append(children, - tok(n.Lparen, len("(")), - tok(n.Rparen, len(")"))) - if n.Ellipsis != 0 { - children = append(children, tok(n.Ellipsis, len("..."))) - } - - case *ast.CaseClause: - if n.List == nil { - children = append(children, - tok(n.Case, len("default"))) - } else { - children = append(children, - tok(n.Case, len("case"))) - } - children = append(children, tok(n.Colon, len(":"))) - - case *ast.ChanType: - switch n.Dir { - case ast.RECV: - children = append(children, tok(n.Begin, len("<-chan"))) - case ast.SEND: - children = append(children, tok(n.Begin, len("chan<-"))) - case ast.RECV | ast.SEND: - children = append(children, tok(n.Begin, len("chan"))) - } - - case *ast.CommClause: - if n.Comm == nil { - children = append(children, - tok(n.Case, len("default"))) - } else { - children = append(children, - tok(n.Case, len("case"))) - } - children = append(children, tok(n.Colon, len(":"))) - - case *ast.Comment: - // nop - - case *ast.CommentGroup: - // nop - - case *ast.CompositeLit: - children = append(children, - tok(n.Lbrace, len("{")), - tok(n.Rbrace, len("{"))) - - case *ast.DeclStmt: - // nop - - case *ast.DeferStmt: - children = append(children, - tok(n.Defer, len("defer"))) - - case *ast.Ellipsis: - children = append(children, - tok(n.Ellipsis, len("..."))) - - case *ast.EmptyStmt: - // nop - - case *ast.ExprStmt: - // nop - - case *ast.Field: - // TODO(adonovan): Field.{Doc,Comment,Tag}? - - case *ast.FieldList: - children = append(children, - tok(n.Opening, len("(")), - tok(n.Closing, len(")"))) - - case *ast.File: - // TODO test: Doc - children = append(children, - tok(n.Package, len("package"))) - - case *ast.ForStmt: - children = append(children, - tok(n.For, len("for"))) - - case *ast.FuncDecl: - // TODO(adonovan): FuncDecl.Comment? - - // Uniquely, FuncDecl breaks the invariant that - // preorder traversal yields tokens in lexical order: - // in fact, FuncDecl.Recv precedes FuncDecl.Type.Func. - // - // As a workaround, we inline the case for FuncType - // here and order things correctly. - // - children = nil // discard ast.Walk(FuncDecl) info subtrees - children = append(children, tok(n.Type.Func, len("func"))) - if n.Recv != nil { - children = append(children, n.Recv) - } - children = append(children, n.Name) - if n.Type.Params != nil { - children = append(children, n.Type.Params) - } - if n.Type.Results != nil { - children = append(children, n.Type.Results) - } - if n.Body != nil { - children = append(children, n.Body) - } - - case *ast.FuncLit: - // nop - - case *ast.FuncType: - if n.Func != 0 { - children = append(children, - tok(n.Func, len("func"))) - } - - case *ast.GenDecl: - children = append(children, - tok(n.TokPos, len(n.Tok.String()))) - if n.Lparen != 0 { - children = append(children, - tok(n.Lparen, len("(")), - tok(n.Rparen, len(")"))) - } - - case *ast.GoStmt: - children = append(children, - tok(n.Go, len("go"))) - - case *ast.Ident: - children = append(children, - tok(n.NamePos, len(n.Name))) - - case *ast.IfStmt: - children = append(children, - tok(n.If, len("if"))) - - case *ast.ImportSpec: - // TODO(adonovan): ImportSpec.{Doc,EndPos}? - - case *ast.IncDecStmt: - children = append(children, - tok(n.TokPos, len(n.Tok.String()))) - - case *ast.IndexExpr: - children = append(children, - tok(n.Lbrack, len("{")), - tok(n.Rbrack, len("}"))) - - case *ast.InterfaceType: - children = append(children, - tok(n.Interface, len("interface"))) - - case *ast.KeyValueExpr: - children = append(children, - tok(n.Colon, len(":"))) - - case *ast.LabeledStmt: - children = append(children, - tok(n.Colon, len(":"))) - - case *ast.MapType: - children = append(children, - tok(n.Map, len("map"))) - - case *ast.ParenExpr: - children = append(children, - tok(n.Lparen, len("(")), - tok(n.Rparen, len(")"))) - - case *ast.RangeStmt: - children = append(children, - tok(n.For, len("for")), - tok(n.TokPos, len(n.Tok.String()))) - - case *ast.ReturnStmt: - children = append(children, - tok(n.Return, len("return"))) - - case *ast.SelectStmt: - children = append(children, - tok(n.Select, len("select"))) - - case *ast.SelectorExpr: - // nop - - case *ast.SendStmt: - children = append(children, - tok(n.Arrow, len("<-"))) - - case *ast.SliceExpr: - children = append(children, - tok(n.Lbrack, len("[")), - tok(n.Rbrack, len("]"))) - - case *ast.StarExpr: - children = append(children, tok(n.Star, len("*"))) - - case *ast.StructType: - children = append(children, tok(n.Struct, len("struct"))) - - case *ast.SwitchStmt: - children = append(children, tok(n.Switch, len("switch"))) - - case *ast.TypeAssertExpr: - children = append(children, - tok(n.Lparen-1, len(".")), - tok(n.Lparen, len("(")), - tok(n.Rparen, len(")"))) - - case *ast.TypeSpec: - // TODO(adonovan): TypeSpec.{Doc,Comment}? - - case *ast.TypeSwitchStmt: - children = append(children, tok(n.Switch, len("switch"))) - - case *ast.UnaryExpr: - children = append(children, tok(n.OpPos, len(n.Op.String()))) - - case *ast.ValueSpec: - // TODO(adonovan): ValueSpec.{Doc,Comment}? - - case *ast.BadDecl, *ast.BadExpr, *ast.BadStmt: - // nop - } - - // TODO(adonovan): opt: merge the logic of ast.Inspect() into - // the switch above so we can make interleaved callbacks for - // both Nodes and Tokens in the right order and avoid the need - // to sort. - sort.Sort(byPos(children)) - - return children -} - -type byPos []ast.Node - -func (sl byPos) Len() int { - return len(sl) -} -func (sl byPos) Less(i, j int) bool { - return sl[i].Pos() < sl[j].Pos() -} -func (sl byPos) Swap(i, j int) { - sl[i], sl[j] = sl[j], sl[i] -} - -// NodeDescription returns a description of the concrete type of n suitable -// for a user interface. -// -// TODO(adonovan): in some cases (e.g. Field, FieldList, Ident, -// StarExpr) we could be much more specific given the path to the AST -// root. Perhaps we should do that. -// -func NodeDescription(n ast.Node) string { - switch n := n.(type) { - case *ast.ArrayType: - return "array type" - case *ast.AssignStmt: - return "assignment" - case *ast.BadDecl: - return "bad declaration" - case *ast.BadExpr: - return "bad expression" - case *ast.BadStmt: - return "bad statement" - case *ast.BasicLit: - return "basic literal" - case *ast.BinaryExpr: - return fmt.Sprintf("binary %s operation", n.Op) - case *ast.BlockStmt: - return "block" - case *ast.BranchStmt: - switch n.Tok { - case token.BREAK: - return "break statement" - case token.CONTINUE: - return "continue statement" - case token.GOTO: - return "goto statement" - case token.FALLTHROUGH: - return "fall-through statement" - } - case *ast.CallExpr: - if len(n.Args) == 1 && !n.Ellipsis.IsValid() { - return "function call (or conversion)" - } - return "function call" - case *ast.CaseClause: - return "case clause" - case *ast.ChanType: - return "channel type" - case *ast.CommClause: - return "communication clause" - case *ast.Comment: - return "comment" - case *ast.CommentGroup: - return "comment group" - case *ast.CompositeLit: - return "composite literal" - case *ast.DeclStmt: - return NodeDescription(n.Decl) + " statement" - case *ast.DeferStmt: - return "defer statement" - case *ast.Ellipsis: - return "ellipsis" - case *ast.EmptyStmt: - return "empty statement" - case *ast.ExprStmt: - return "expression statement" - case *ast.Field: - // Can be any of these: - // struct {x, y int} -- struct field(s) - // struct {T} -- anon struct field - // interface {I} -- interface embedding - // interface {f()} -- interface method - // func (A) func(B) C -- receiver, param(s), result(s) - return "field/method/parameter" - case *ast.FieldList: - return "field/method/parameter list" - case *ast.File: - return "source file" - case *ast.ForStmt: - return "for loop" - case *ast.FuncDecl: - return "function declaration" - case *ast.FuncLit: - return "function literal" - case *ast.FuncType: - return "function type" - case *ast.GenDecl: - switch n.Tok { - case token.IMPORT: - return "import declaration" - case token.CONST: - return "constant declaration" - case token.TYPE: - return "type declaration" - case token.VAR: - return "variable declaration" - } - case *ast.GoStmt: - return "go statement" - case *ast.Ident: - return "identifier" - case *ast.IfStmt: - return "if statement" - case *ast.ImportSpec: - return "import specification" - case *ast.IncDecStmt: - if n.Tok == token.INC { - return "increment statement" - } - return "decrement statement" - case *ast.IndexExpr: - return "index expression" - case *ast.InterfaceType: - return "interface type" - case *ast.KeyValueExpr: - return "key/value association" - case *ast.LabeledStmt: - return "statement label" - case *ast.MapType: - return "map type" - case *ast.Package: - return "package" - case *ast.ParenExpr: - return "parenthesized " + NodeDescription(n.X) - case *ast.RangeStmt: - return "range loop" - case *ast.ReturnStmt: - return "return statement" - case *ast.SelectStmt: - return "select statement" - case *ast.SelectorExpr: - return "selector" - case *ast.SendStmt: - return "channel send" - case *ast.SliceExpr: - return "slice expression" - case *ast.StarExpr: - return "*-operation" // load/store expr or pointer type - case *ast.StructType: - return "struct type" - case *ast.SwitchStmt: - return "switch statement" - case *ast.TypeAssertExpr: - return "type assertion" - case *ast.TypeSpec: - return "type specification" - case *ast.TypeSwitchStmt: - return "type switch" - case *ast.UnaryExpr: - return fmt.Sprintf("unary %s operation", n.Op) - case *ast.ValueSpec: - return "value specification" - - } - panic(fmt.Sprintf("unexpected node type: %T", n)) -}