+++ /dev/null
-// Package analysisutil defines various helper functions
-// used by two or more packages beneath go/analysis.
-package analysisutil
-
-import (
- "bytes"
- "go/ast"
- "go/printer"
- "go/token"
- "go/types"
- "io/ioutil"
-)
-
-// Format returns a string representation of the expression.
-func Format(fset *token.FileSet, x ast.Expr) string {
- var b bytes.Buffer
- printer.Fprint(&b, fset, x)
- return b.String()
-}
-
-// HasSideEffects reports whether evaluation of e has side effects.
-func HasSideEffects(info *types.Info, e ast.Expr) bool {
- safe := true
- ast.Inspect(e, func(node ast.Node) bool {
- switch n := node.(type) {
- case *ast.CallExpr:
- typVal := info.Types[n.Fun]
- switch {
- case typVal.IsType():
- // Type conversion, which is safe.
- case typVal.IsBuiltin():
- // Builtin func, conservatively assumed to not
- // be safe for now.
- safe = false
- return false
- default:
- // A non-builtin func or method call.
- // Conservatively assume that all of them have
- // side effects for now.
- safe = false
- return false
- }
- case *ast.UnaryExpr:
- if n.Op == token.ARROW {
- safe = false
- return false
- }
- }
- return true
- })
- return !safe
-}
-
-// Unparen returns e with any enclosing parentheses stripped.
-func Unparen(e ast.Expr) ast.Expr {
- for {
- p, ok := e.(*ast.ParenExpr)
- if !ok {
- return e
- }
- e = p.X
- }
-}
-
-// ReadFile reads a file and adds it to the FileSet
-// so that we can report errors against it using lineStart.
-func ReadFile(fset *token.FileSet, filename string) ([]byte, *token.File, error) {
- content, err := ioutil.ReadFile(filename)
- if err != nil {
- return nil, nil, err
- }
- tf := fset.AddFile(filename, -1, len(content))
- tf.SetLinesForContent(content)
- return content, tf, nil
-}
-
-// LineStart returns the position of the start of the specified line
-// within file f, or NoPos if there is no line of that number.
-func LineStart(f *token.File, line int) token.Pos {
- // Use binary search to find the start offset of this line.
- //
- // TODO(adonovan): eventually replace this function with the
- // simpler and more efficient (*go/token.File).LineStart, added
- // in go1.12.
-
- min := 0 // inclusive
- max := f.Size() // exclusive
- for {
- offset := (min + max) / 2
- pos := f.Pos(offset)
- posn := f.Position(pos)
- if posn.Line == line {
- return pos - (token.Pos(posn.Column) - 1)
- }
-
- if min+1 >= max {
- return token.NoPos
- }
-
- if posn.Line < line {
- min = offset
- } else {
- max = offset
- }
- }
-}
-
-// Imports returns true if path is imported by pkg.
-func Imports(pkg *types.Package, path string) bool {
- for _, imp := range pkg.Imports() {
- if imp.Path() == path {
- return true
- }
- }
- return false
-}