+++ /dev/null
-// 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.
-
-package main
-
-import (
- "bytes"
- "flag"
- "fmt"
- "go/ast"
- "go/parser"
- "go/printer"
- "go/token"
- "io"
- "io/ioutil"
- "log"
- "os"
- "path/filepath"
- "sort"
- "strconv"
- "strings"
-)
-
-const usageMessage = "" +
- `Usage of 'go tool cover':
-Given a coverage profile produced by 'go test':
- go test -coverprofile=c.out
-
-Open a web browser displaying annotated source code:
- go tool cover -html=c.out
-
-Write out an HTML file instead of launching a web browser:
- go tool cover -html=c.out -o coverage.html
-
-Display coverage percentages to stdout for each function:
- go tool cover -func=c.out
-
-Finally, to generate modified source code with coverage annotations
-(what go test -cover does):
- go tool cover -mode=set -var=CoverageVariableName program.go
-`
-
-func usage() {
- fmt.Fprintln(os.Stderr, usageMessage)
- fmt.Fprintln(os.Stderr, "Flags:")
- flag.PrintDefaults()
- fmt.Fprintln(os.Stderr, "\n Only one of -html, -func, or -mode may be set.")
- os.Exit(2)
-}
-
-var (
- mode = flag.String("mode", "", "coverage mode: set, count, atomic")
- varVar = flag.String("var", "GoCover", "name of coverage variable to generate")
- output = flag.String("o", "", "file for output; default: stdout")
- htmlOut = flag.String("html", "", "generate HTML representation of coverage profile")
- funcOut = flag.String("func", "", "output coverage profile information for each function")
-)
-
-var profile string // The profile to read; the value of -html or -func
-
-var counterStmt func(*File, ast.Expr) ast.Stmt
-
-const (
- atomicPackagePath = "sync/atomic"
- atomicPackageName = "_cover_atomic_"
-)
-
-func main() {
- flag.Usage = usage
- flag.Parse()
-
- // Usage information when no arguments.
- if flag.NFlag() == 0 && flag.NArg() == 0 {
- flag.Usage()
- }
-
- err := parseFlags()
- if err != nil {
- fmt.Fprintln(os.Stderr, err)
- fmt.Fprintln(os.Stderr, `For usage information, run "go tool cover -help"`)
- os.Exit(2)
- }
-
- // Generate coverage-annotated source.
- if *mode != "" {
- annotate(flag.Arg(0))
- return
- }
-
- // Output HTML or function coverage information.
- if *htmlOut != "" {
- err = htmlOutput(profile, *output)
- } else {
- err = funcOutput(profile, *output)
- }
-
- if err != nil {
- fmt.Fprintf(os.Stderr, "cover: %v\n", err)
- os.Exit(2)
- }
-}
-
-// parseFlags sets the profile and counterStmt globals and performs validations.
-func parseFlags() error {
- profile = *htmlOut
- if *funcOut != "" {
- if profile != "" {
- return fmt.Errorf("too many options")
- }
- profile = *funcOut
- }
-
- // Must either display a profile or rewrite Go source.
- if (profile == "") == (*mode == "") {
- return fmt.Errorf("too many options")
- }
-
- if *mode != "" {
- switch *mode {
- case "set":
- counterStmt = setCounterStmt
- case "count":
- counterStmt = incCounterStmt
- case "atomic":
- counterStmt = atomicCounterStmt
- default:
- return fmt.Errorf("unknown -mode %v", *mode)
- }
-
- if flag.NArg() == 0 {
- return fmt.Errorf("missing source file")
- } else if flag.NArg() == 1 {
- return nil
- }
- } else if flag.NArg() == 0 {
- return nil
- }
- return fmt.Errorf("too many arguments")
-}
-
-// Block represents the information about a basic block to be recorded in the analysis.
-// Note: Our definition of basic block is based on control structures; we don't break
-// apart && and ||. We could but it doesn't seem important enough to bother.
-type Block struct {
- startByte token.Pos
- endByte token.Pos
- numStmt int
-}
-
-// File is a wrapper for the state of a file used in the parser.
-// The basic parse tree walker is a method of this type.
-type File struct {
- fset *token.FileSet
- name string // Name of file.
- astFile *ast.File
- blocks []Block
- atomicPkg string // Package name for "sync/atomic" in this file.
-}
-
-// Visit implements the ast.Visitor interface.
-func (f *File) Visit(node ast.Node) ast.Visitor {
- switch n := node.(type) {
- case *ast.BlockStmt:
- // If it's a switch or select, the body is a list of case clauses; don't tag the block itself.
- if len(n.List) > 0 {
- switch n.List[0].(type) {
- case *ast.CaseClause: // switch
- for _, n := range n.List {
- clause := n.(*ast.CaseClause)
- clause.Body = f.addCounters(clause.Pos(), clause.End(), clause.Body, false)
- }
- return f
- case *ast.CommClause: // select
- for _, n := range n.List {
- clause := n.(*ast.CommClause)
- clause.Body = f.addCounters(clause.Pos(), clause.End(), clause.Body, false)
- }
- return f
- }
- }
- n.List = f.addCounters(n.Lbrace, n.Rbrace+1, n.List, true) // +1 to step past closing brace.
- case *ast.IfStmt:
- ast.Walk(f, n.Body)
- if n.Else == nil {
- return nil
- }
- // The elses are special, because if we have
- // if x {
- // } else if y {
- // }
- // we want to cover the "if y". To do this, we need a place to drop the counter,
- // so we add a hidden block:
- // if x {
- // } else {
- // if y {
- // }
- // }
- switch stmt := n.Else.(type) {
- case *ast.IfStmt:
- block := &ast.BlockStmt{
- Lbrace: n.Body.End(), // Start at end of the "if" block so the covered part looks like it starts at the "else".
- List: []ast.Stmt{stmt},
- Rbrace: stmt.End(),
- }
- n.Else = block
- case *ast.BlockStmt:
- stmt.Lbrace = n.Body.End() // Start at end of the "if" block so the covered part looks like it starts at the "else".
- default:
- panic("unexpected node type in if")
- }
- ast.Walk(f, n.Else)
- return nil
- case *ast.SelectStmt:
- // Don't annotate an empty select - creates a syntax error.
- if n.Body == nil || len(n.Body.List) == 0 {
- return nil
- }
- case *ast.SwitchStmt:
- // Don't annotate an empty switch - creates a syntax error.
- if n.Body == nil || len(n.Body.List) == 0 {
- return nil
- }
- case *ast.TypeSwitchStmt:
- // Don't annotate an empty type switch - creates a syntax error.
- if n.Body == nil || len(n.Body.List) == 0 {
- return nil
- }
- }
- return f
-}
-
-// unquote returns the unquoted string.
-func unquote(s string) string {
- t, err := strconv.Unquote(s)
- if err != nil {
- log.Fatalf("cover: improperly quoted string %q\n", s)
- }
- return t
-}
-
-// addImport adds an import for the specified path, if one does not already exist, and returns
-// the local package name.
-func (f *File) addImport(path string) string {
- // Does the package already import it?
- for _, s := range f.astFile.Imports {
- if unquote(s.Path.Value) == path {
- if s.Name != nil {
- return s.Name.Name
- }
- return filepath.Base(path)
- }
- }
- newImport := &ast.ImportSpec{
- Name: ast.NewIdent(atomicPackageName),
- Path: &ast.BasicLit{
- Kind: token.STRING,
- Value: fmt.Sprintf("%q", path),
- },
- }
- impDecl := &ast.GenDecl{
- Tok: token.IMPORT,
- Specs: []ast.Spec{
- newImport,
- },
- }
- // Make the new import the first Decl in the file.
- astFile := f.astFile
- astFile.Decls = append(astFile.Decls, nil)
- copy(astFile.Decls[1:], astFile.Decls[0:])
- astFile.Decls[0] = impDecl
- astFile.Imports = append(astFile.Imports, newImport)
-
- // Now refer to the package, just in case it ends up unused.
- // That is, append to the end of the file the declaration
- // var _ = _cover_atomic_.AddUint32
- reference := &ast.GenDecl{
- Tok: token.VAR,
- Specs: []ast.Spec{
- &ast.ValueSpec{
- Names: []*ast.Ident{
- ast.NewIdent("_"),
- },
- Values: []ast.Expr{
- &ast.SelectorExpr{
- X: ast.NewIdent(atomicPackageName),
- Sel: ast.NewIdent("AddUint32"),
- },
- },
- },
- },
- }
- astFile.Decls = append(astFile.Decls, reference)
- return atomicPackageName
-}
-
-var slashslash = []byte("//")
-
-// initialComments returns the prefix of content containing only
-// whitespace and line comments. Any +build directives must appear
-// within this region. This approach is more reliable than using
-// go/printer to print a modified AST containing comments.
-//
-func initialComments(content []byte) []byte {
- // Derived from go/build.Context.shouldBuild.
- end := 0
- p := content
- for len(p) > 0 {
- line := p
- if i := bytes.IndexByte(line, '\n'); i >= 0 {
- line, p = line[:i], p[i+1:]
- } else {
- p = p[len(p):]
- }
- line = bytes.TrimSpace(line)
- if len(line) == 0 { // Blank line.
- end = len(content) - len(p)
- continue
- }
- if !bytes.HasPrefix(line, slashslash) { // Not comment line.
- break
- }
- }
- return content[:end]
-}
-
-func annotate(name string) {
- fset := token.NewFileSet()
- content, err := ioutil.ReadFile(name)
- if err != nil {
- log.Fatalf("cover: %s: %s", name, err)
- }
- parsedFile, err := parser.ParseFile(fset, name, content, parser.ParseComments)
- if err != nil {
- log.Fatalf("cover: %s: %s", name, err)
- }
- parsedFile.Comments = trimComments(parsedFile, fset)
-
- file := &File{
- fset: fset,
- name: name,
- astFile: parsedFile,
- }
- if *mode == "atomic" {
- file.atomicPkg = file.addImport(atomicPackagePath)
- }
- ast.Walk(file, file.astFile)
- fd := os.Stdout
- if *output != "" {
- var err error
- fd, err = os.Create(*output)
- if err != nil {
- log.Fatalf("cover: %s", err)
- }
- }
- fd.Write(initialComments(content)) // Retain '// +build' directives.
- file.print(fd)
- // After printing the source tree, add some declarations for the counters etc.
- // We could do this by adding to the tree, but it's easier just to print the text.
- file.addVariables(fd)
-}
-
-// trimComments drops all but the //go: comments, some of which are semantically important.
-// We drop all others because they can appear in places that cause our counters
-// to appear in syntactically incorrect places. //go: appears at the beginning of
-// the line and is syntactically safe.
-func trimComments(file *ast.File, fset *token.FileSet) []*ast.CommentGroup {
- var comments []*ast.CommentGroup
- for _, group := range file.Comments {
- var list []*ast.Comment
- for _, comment := range group.List {
- if strings.HasPrefix(comment.Text, "//go:") && fset.Position(comment.Slash).Column == 1 {
- list = append(list, comment)
- }
- }
- if list != nil {
- comments = append(comments, &ast.CommentGroup{List: list})
- }
- }
- return comments
-}
-
-func (f *File) print(w io.Writer) {
- printer.Fprint(w, f.fset, f.astFile)
-}
-
-// intLiteral returns an ast.BasicLit representing the integer value.
-func (f *File) intLiteral(i int) *ast.BasicLit {
- node := &ast.BasicLit{
- Kind: token.INT,
- Value: fmt.Sprint(i),
- }
- return node
-}
-
-// index returns an ast.BasicLit representing the number of counters present.
-func (f *File) index() *ast.BasicLit {
- return f.intLiteral(len(f.blocks))
-}
-
-// setCounterStmt returns the expression: __count[23] = 1.
-func setCounterStmt(f *File, counter ast.Expr) ast.Stmt {
- return &ast.AssignStmt{
- Lhs: []ast.Expr{counter},
- Tok: token.ASSIGN,
- Rhs: []ast.Expr{f.intLiteral(1)},
- }
-}
-
-// incCounterStmt returns the expression: __count[23]++.
-func incCounterStmt(f *File, counter ast.Expr) ast.Stmt {
- return &ast.IncDecStmt{
- X: counter,
- Tok: token.INC,
- }
-}
-
-// atomicCounterStmt returns the expression: atomic.AddUint32(&__count[23], 1)
-func atomicCounterStmt(f *File, counter ast.Expr) ast.Stmt {
- return &ast.ExprStmt{
- X: &ast.CallExpr{
- Fun: &ast.SelectorExpr{
- X: ast.NewIdent(f.atomicPkg),
- Sel: ast.NewIdent("AddUint32"),
- },
- Args: []ast.Expr{&ast.UnaryExpr{
- Op: token.AND,
- X: counter,
- },
- f.intLiteral(1),
- },
- },
- }
-}
-
-// newCounter creates a new counter expression of the appropriate form.
-func (f *File) newCounter(start, end token.Pos, numStmt int) ast.Stmt {
- counter := &ast.IndexExpr{
- X: &ast.SelectorExpr{
- X: ast.NewIdent(*varVar),
- Sel: ast.NewIdent("Count"),
- },
- Index: f.index(),
- }
- stmt := counterStmt(f, counter)
- f.blocks = append(f.blocks, Block{start, end, numStmt})
- return stmt
-}
-
-// addCounters takes a list of statements and adds counters to the beginning of
-// each basic block at the top level of that list. For instance, given
-//
-// S1
-// if cond {
-// S2
-// }
-// S3
-//
-// counters will be added before S1 and before S3. The block containing S2
-// will be visited in a separate call.
-// TODO: Nested simple blocks get unnecessary (but correct) counters
-func (f *File) addCounters(pos, blockEnd token.Pos, list []ast.Stmt, extendToClosingBrace bool) []ast.Stmt {
- // Special case: make sure we add a counter to an empty block. Can't do this below
- // or we will add a counter to an empty statement list after, say, a return statement.
- if len(list) == 0 {
- return []ast.Stmt{f.newCounter(pos, blockEnd, 0)}
- }
- // We have a block (statement list), but it may have several basic blocks due to the
- // appearance of statements that affect the flow of control.
- var newList []ast.Stmt
- for {
- // Find first statement that affects flow of control (break, continue, if, etc.).
- // It will be the last statement of this basic block.
- var last int
- end := blockEnd
- for last = 0; last < len(list); last++ {
- end = f.statementBoundary(list[last])
- if f.endsBasicSourceBlock(list[last]) {
- extendToClosingBrace = false // Block is broken up now.
- last++
- break
- }
- }
- if extendToClosingBrace {
- end = blockEnd
- }
- if pos != end { // Can have no source to cover if e.g. blocks abut.
- newList = append(newList, f.newCounter(pos, end, last))
- }
- newList = append(newList, list[0:last]...)
- list = list[last:]
- if len(list) == 0 {
- break
- }
- pos = list[0].Pos()
- }
- return newList
-}
-
-// hasFuncLiteral reports the existence and position of the first func literal
-// in the node, if any. If a func literal appears, it usually marks the termination
-// of a basic block because the function body is itself a block.
-// Therefore we draw a line at the start of the body of the first function literal we find.
-// TODO: what if there's more than one? Probably doesn't matter much.
-func hasFuncLiteral(n ast.Node) (bool, token.Pos) {
- if n == nil {
- return false, 0
- }
- var literal funcLitFinder
- ast.Walk(&literal, n)
- return literal.found(), token.Pos(literal)
-}
-
-// statementBoundary finds the location in s that terminates the current basic
-// block in the source.
-func (f *File) statementBoundary(s ast.Stmt) token.Pos {
- // Control flow statements are easy.
- switch s := s.(type) {
- case *ast.BlockStmt:
- // Treat blocks like basic blocks to avoid overlapping counters.
- return s.Lbrace
- case *ast.IfStmt:
- found, pos := hasFuncLiteral(s.Init)
- if found {
- return pos
- }
- found, pos = hasFuncLiteral(s.Cond)
- if found {
- return pos
- }
- return s.Body.Lbrace
- case *ast.ForStmt:
- found, pos := hasFuncLiteral(s.Init)
- if found {
- return pos
- }
- found, pos = hasFuncLiteral(s.Cond)
- if found {
- return pos
- }
- found, pos = hasFuncLiteral(s.Post)
- if found {
- return pos
- }
- return s.Body.Lbrace
- case *ast.LabeledStmt:
- return f.statementBoundary(s.Stmt)
- case *ast.RangeStmt:
- found, pos := hasFuncLiteral(s.X)
- if found {
- return pos
- }
- return s.Body.Lbrace
- case *ast.SwitchStmt:
- found, pos := hasFuncLiteral(s.Init)
- if found {
- return pos
- }
- found, pos = hasFuncLiteral(s.Tag)
- if found {
- return pos
- }
- return s.Body.Lbrace
- case *ast.SelectStmt:
- return s.Body.Lbrace
- case *ast.TypeSwitchStmt:
- found, pos := hasFuncLiteral(s.Init)
- if found {
- return pos
- }
- return s.Body.Lbrace
- }
- // If not a control flow statement, it is a declaration, expression, call, etc. and it may have a function literal.
- // If it does, that's tricky because we want to exclude the body of the function from this block.
- // Draw a line at the start of the body of the first function literal we find.
- // TODO: what if there's more than one? Probably doesn't matter much.
- found, pos := hasFuncLiteral(s)
- if found {
- return pos
- }
- return s.End()
-}
-
-// endsBasicSourceBlock reports whether s changes the flow of control: break, if, etc.,
-// or if it's just problematic, for instance contains a function literal, which will complicate
-// accounting due to the block-within-an expression.
-func (f *File) endsBasicSourceBlock(s ast.Stmt) bool {
- switch s := s.(type) {
- case *ast.BlockStmt:
- // Treat blocks like basic blocks to avoid overlapping counters.
- return true
- case *ast.BranchStmt:
- return true
- case *ast.ForStmt:
- return true
- case *ast.IfStmt:
- return true
- case *ast.LabeledStmt:
- return f.endsBasicSourceBlock(s.Stmt)
- case *ast.RangeStmt:
- return true
- case *ast.SwitchStmt:
- return true
- case *ast.SelectStmt:
- return true
- case *ast.TypeSwitchStmt:
- return true
- case *ast.ExprStmt:
- // Calls to panic change the flow.
- // We really should verify that "panic" is the predefined function,
- // but without type checking we can't and the likelihood of it being
- // an actual problem is vanishingly small.
- if call, ok := s.X.(*ast.CallExpr); ok {
- if ident, ok := call.Fun.(*ast.Ident); ok && ident.Name == "panic" && len(call.Args) == 1 {
- return true
- }
- }
- }
- found, _ := hasFuncLiteral(s)
- return found
-}
-
-// funcLitFinder implements the ast.Visitor pattern to find the location of any
-// function literal in a subtree.
-type funcLitFinder token.Pos
-
-func (f *funcLitFinder) Visit(node ast.Node) (w ast.Visitor) {
- if f.found() {
- return nil // Prune search.
- }
- switch n := node.(type) {
- case *ast.FuncLit:
- *f = funcLitFinder(n.Body.Lbrace)
- return nil // Prune search.
- }
- return f
-}
-
-func (f *funcLitFinder) found() bool {
- return token.Pos(*f) != token.NoPos
-}
-
-// Sort interface for []block1; used for self-check in addVariables.
-
-type block1 struct {
- Block
- index int
-}
-
-type blockSlice []block1
-
-func (b blockSlice) Len() int { return len(b) }
-func (b blockSlice) Less(i, j int) bool { return b[i].startByte < b[j].startByte }
-func (b blockSlice) Swap(i, j int) { b[i], b[j] = b[j], b[i] }
-
-// offset translates a token position into a 0-indexed byte offset.
-func (f *File) offset(pos token.Pos) int {
- return f.fset.Position(pos).Offset
-}
-
-// addVariables adds to the end of the file the declarations to set up the counter and position variables.
-func (f *File) addVariables(w io.Writer) {
- // Self-check: Verify that the instrumented basic blocks are disjoint.
- t := make([]block1, len(f.blocks))
- for i := range f.blocks {
- t[i].Block = f.blocks[i]
- t[i].index = i
- }
- sort.Sort(blockSlice(t))
- for i := 1; i < len(t); i++ {
- if t[i-1].endByte > t[i].startByte {
- fmt.Fprintf(os.Stderr, "cover: internal error: block %d overlaps block %d\n", t[i-1].index, t[i].index)
- // Note: error message is in byte positions, not token positions.
- fmt.Fprintf(os.Stderr, "\t%s:#%d,#%d %s:#%d,#%d\n",
- f.name, f.offset(t[i-1].startByte), f.offset(t[i-1].endByte),
- f.name, f.offset(t[i].startByte), f.offset(t[i].endByte))
- }
- }
-
- // Declare the coverage struct as a package-level variable.
- fmt.Fprintf(w, "\nvar %s = struct {\n", *varVar)
- fmt.Fprintf(w, "\tCount [%d]uint32\n", len(f.blocks))
- fmt.Fprintf(w, "\tPos [3 * %d]uint32\n", len(f.blocks))
- fmt.Fprintf(w, "\tNumStmt [%d]uint16\n", len(f.blocks))
- fmt.Fprintf(w, "} {\n")
-
- // Initialize the position array field.
- fmt.Fprintf(w, "\tPos: [3 * %d]uint32{\n", len(f.blocks))
-
- // A nice long list of positions. Each position is encoded as follows to reduce size:
- // - 32-bit starting line number
- // - 32-bit ending line number
- // - (16 bit ending column number << 16) | (16-bit starting column number).
- for i, block := range f.blocks {
- start := f.fset.Position(block.startByte)
- end := f.fset.Position(block.endByte)
- fmt.Fprintf(w, "\t\t%d, %d, %#x, // [%d]\n", start.Line, end.Line, (end.Column&0xFFFF)<<16|(start.Column&0xFFFF), i)
- }
-
- // Close the position array.
- fmt.Fprintf(w, "\t},\n")
-
- // Initialize the position array field.
- fmt.Fprintf(w, "\tNumStmt: [%d]uint16{\n", len(f.blocks))
-
- // A nice long list of statements-per-block, so we can give a conventional
- // valuation of "percent covered". To save space, it's a 16-bit number, so we
- // clamp it if it overflows - won't matter in practice.
- for i, block := range f.blocks {
- n := block.numStmt
- if n > 1<<16-1 {
- n = 1<<16 - 1
- }
- fmt.Fprintf(w, "\t\t%d, // %d\n", n, i)
- }
-
- // Close the statements-per-block array.
- fmt.Fprintf(w, "\t},\n")
-
- // Close the struct initialization.
- fmt.Fprintf(w, "}\n")
-}
projects / dotfiles / .git / blobdiff