Adding upstream version 1.16.10.upstream/1.16.10upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 246 insertions, 0 deletions

diff --git a/src/cmd/cover/func.go b/src/cmd/cover/func.go
new file mode 100644
index 0000000..ce7c771
--- /dev/null
+++ b/src/cmd/cover/func.go
@@ -0,0 +1,246 @@
+// 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.
+
+// This file implements the visitor that computes the (line, column)-(line-column) range for each function.
+
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	exec "internal/execabs"
+	"io"
+	"os"
+	"path"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"text/tabwriter"
+)
+
+// funcOutput takes two file names as arguments, a coverage profile to read as input and an output
+// file to write ("" means to write to standard output). The function reads the profile and produces
+// as output the coverage data broken down by function, like this:
+//
+//	fmt/format.go:30:	init			100.0%
+//	fmt/format.go:57:	clearflags		100.0%
+//	...
+//	fmt/scan.go:1046:	doScan			100.0%
+//	fmt/scan.go:1075:	advance			96.2%
+//	fmt/scan.go:1119:	doScanf			96.8%
+//	total:		(statements)			91.9%
+
+func funcOutput(profile, outputFile string) error {
+	profiles, err := ParseProfiles(profile)
+	if err != nil {
+		return err
+	}
+
+	dirs, err := findPkgs(profiles)
+	if err != nil {
+		return err
+	}
+
+	var out *bufio.Writer
+	if outputFile == "" {
+		out = bufio.NewWriter(os.Stdout)
+	} else {
+		fd, err := os.Create(outputFile)
+		if err != nil {
+			return err
+		}
+		defer fd.Close()
+		out = bufio.NewWriter(fd)
+	}
+	defer out.Flush()
+
+	tabber := tabwriter.NewWriter(out, 1, 8, 1, '\t', 0)
+	defer tabber.Flush()
+
+	var total, covered int64
+	for _, profile := range profiles {
+		fn := profile.FileName
+		file, err := findFile(dirs, fn)
+		if err != nil {
+			return err
+		}
+		funcs, err := findFuncs(file)
+		if err != nil {
+			return err
+		}
+		// Now match up functions and profile blocks.
+		for _, f := range funcs {
+			c, t := f.coverage(profile)
+			fmt.Fprintf(tabber, "%s:%d:\t%s\t%.1f%%\n", fn, f.startLine, f.name, percent(c, t))
+			total += t
+			covered += c
+		}
+	}
+	fmt.Fprintf(tabber, "total:\t(statements)\t%.1f%%\n", percent(covered, total))
+
+	return nil
+}
+
+// findFuncs parses the file and returns a slice of FuncExtent descriptors.
+func findFuncs(name string) ([]*FuncExtent, error) {
+	fset := token.NewFileSet()
+	parsedFile, err := parser.ParseFile(fset, name, nil, 0)
+	if err != nil {
+		return nil, err
+	}
+	visitor := &FuncVisitor{
+		fset:    fset,
+		name:    name,
+		astFile: parsedFile,
+	}
+	ast.Walk(visitor, visitor.astFile)
+	return visitor.funcs, nil
+}
+
+// FuncExtent describes a function's extent in the source by file and position.
+type FuncExtent struct {
+	name      string
+	startLine int
+	startCol  int
+	endLine   int
+	endCol    int
+}
+
+// FuncVisitor implements the visitor that builds the function position list for a file.
+type FuncVisitor struct {
+	fset    *token.FileSet
+	name    string // Name of file.
+	astFile *ast.File
+	funcs   []*FuncExtent
+}
+
+// Visit implements the ast.Visitor interface.
+func (v *FuncVisitor) Visit(node ast.Node) ast.Visitor {
+	switch n := node.(type) {
+	case *ast.FuncDecl:
+		if n.Body == nil {
+			// Do not count declarations of assembly functions.
+			break
+		}
+		start := v.fset.Position(n.Pos())
+		end := v.fset.Position(n.End())
+		fe := &FuncExtent{
+			name:      n.Name.Name,
+			startLine: start.Line,
+			startCol:  start.Column,
+			endLine:   end.Line,
+			endCol:    end.Column,
+		}
+		v.funcs = append(v.funcs, fe)
+	}
+	return v
+}
+
+// coverage returns the fraction of the statements in the function that were covered, as a numerator and denominator.
+func (f *FuncExtent) coverage(profile *Profile) (num, den int64) {
+	// We could avoid making this n^2 overall by doing a single scan and annotating the functions,
+	// but the sizes of the data structures is never very large and the scan is almost instantaneous.
+	var covered, total int64
+	// The blocks are sorted, so we can stop counting as soon as we reach the end of the relevant block.
+	for _, b := range profile.Blocks {
+		if b.StartLine > f.endLine || (b.StartLine == f.endLine && b.StartCol >= f.endCol) {
+			// Past the end of the function.
+			break
+		}
+		if b.EndLine < f.startLine || (b.EndLine == f.startLine && b.EndCol <= f.startCol) {
+			// Before the beginning of the function
+			continue
+		}
+		total += int64(b.NumStmt)
+		if b.Count > 0 {
+			covered += int64(b.NumStmt)
+		}
+	}
+	return covered, total
+}
+
+// Pkg describes a single package, compatible with the JSON output from 'go list'; see 'go help list'.
+type Pkg struct {
+	ImportPath string
+	Dir        string
+	Error      *struct {
+		Err string
+	}
+}
+
+func findPkgs(profiles []*Profile) (map[string]*Pkg, error) {
+	// Run go list to find the location of every package we care about.
+	pkgs := make(map[string]*Pkg)
+	var list []string
+	for _, profile := range profiles {
+		if strings.HasPrefix(profile.FileName, ".") || filepath.IsAbs(profile.FileName) {
+			// Relative or absolute path.
+			continue
+		}
+		pkg := path.Dir(profile.FileName)
+		if _, ok := pkgs[pkg]; !ok {
+			pkgs[pkg] = nil
+			list = append(list, pkg)
+		}
+	}
+
+	if len(list) == 0 {
+		return pkgs, nil
+	}
+
+	// Note: usually run as "go tool cover" in which case $GOROOT is set,
+	// in which case runtime.GOROOT() does exactly what we want.
+	goTool := filepath.Join(runtime.GOROOT(), "bin/go")
+	cmd := exec.Command(goTool, append([]string{"list", "-e", "-json"}, list...)...)
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+	stdout, err := cmd.Output()
+	if err != nil {
+		return nil, fmt.Errorf("cannot run go list: %v\n%s", err, stderr.Bytes())
+	}
+	dec := json.NewDecoder(bytes.NewReader(stdout))
+	for {
+		var pkg Pkg
+		err := dec.Decode(&pkg)
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, fmt.Errorf("decoding go list json: %v", err)
+		}
+		pkgs[pkg.ImportPath] = &pkg
+	}
+	return pkgs, nil
+}
+
+// findFile finds the location of the named file in GOROOT, GOPATH etc.
+func findFile(pkgs map[string]*Pkg, file string) (string, error) {
+	if strings.HasPrefix(file, ".") || filepath.IsAbs(file) {
+		// Relative or absolute path.
+		return file, nil
+	}
+	pkg := pkgs[path.Dir(file)]
+	if pkg != nil {
+		if pkg.Dir != "" {
+			return filepath.Join(pkg.Dir, path.Base(file)), nil
+		}
+		if pkg.Error != nil {
+			return "", errors.New(pkg.Error.Err)
+		}
+	}
+	return "", fmt.Errorf("did not find package for %s in go list output", file)
+}
+
+func percent(covered, total int64) float64 {
+	if total == 0 {
+		total = 1 // Avoid zero denominator.
+	}
+	return 100.0 * float64(covered) / float64(total)
+}