golangci-lint/pkg/golinters/scopelint.go
2018-11-07 09:11:08 +03:00

140 lines
3.6 KiB
Go

package golinters
import (
"context"
"fmt"
"go/ast"
"go/token"
"github.com/golangci/golangci-lint/pkg/lint/linter"
"github.com/golangci/golangci-lint/pkg/result"
)
type Scopelint struct{}
func (Scopelint) Name() string {
return "scopelint"
}
func (Scopelint) Desc() string {
return "Scopelint checks for unpinned variables in go programs"
}
func (lint Scopelint) Run(ctx context.Context, lintCtx *linter.Context) ([]result.Issue, error) {
var res []result.Issue
for _, f := range lintCtx.ASTCache.GetAllValidFiles() {
n := Node{
fset: f.Fset,
dangerObjects: map[*ast.Object]struct{}{},
unsafeObjects: map[*ast.Object]struct{}{},
skipFuncs: map[*ast.FuncLit]struct{}{},
issues: &res,
}
ast.Walk(&n, f.F)
}
return res, nil
}
// The code below is copy-pasted from https://github.com/kyoh86/scopelint
// Node represents a Node being linted.
type Node struct {
fset *token.FileSet
dangerObjects map[*ast.Object]struct{}
unsafeObjects map[*ast.Object]struct{}
skipFuncs map[*ast.FuncLit]struct{}
issues *[]result.Issue
}
// Visit method is invoked for each node encountered by Walk.
// If the result visitor w is not nil, Walk visits each of the children
// of node with the visitor w, followed by a call of w.Visit(nil).
//nolint:gocyclo,gocritic
func (f *Node) Visit(node ast.Node) ast.Visitor {
switch typedNode := node.(type) {
case *ast.ForStmt:
switch init := typedNode.Init.(type) {
case *ast.AssignStmt:
for _, lh := range init.Lhs {
switch tlh := lh.(type) {
case *ast.Ident:
f.unsafeObjects[tlh.Obj] = struct{}{}
}
}
}
case *ast.RangeStmt:
// Memory variables declarated in range statement
switch k := typedNode.Key.(type) {
case *ast.Ident:
f.unsafeObjects[k.Obj] = struct{}{}
}
switch v := typedNode.Value.(type) {
case *ast.Ident:
f.unsafeObjects[v.Obj] = struct{}{}
}
case *ast.UnaryExpr:
if typedNode.Op == token.AND {
switch ident := typedNode.X.(type) {
case *ast.Ident:
if _, unsafe := f.unsafeObjects[ident.Obj]; unsafe {
f.errorf(ident, "Using a reference for the variable on range scope %s", formatCode(ident.Name, nil))
}
}
}
case *ast.Ident:
if _, obj := f.dangerObjects[typedNode.Obj]; obj {
// It is the naked variable in scope of range statement.
f.errorf(node, "Using the variable on range scope %s in function literal", formatCode(typedNode.Name, nil))
break
}
case *ast.CallExpr:
// Ignore func literals that'll be called immediately.
switch funcLit := typedNode.Fun.(type) {
case *ast.FuncLit:
f.skipFuncs[funcLit] = struct{}{}
}
case *ast.FuncLit:
if _, skip := f.skipFuncs[typedNode]; !skip {
dangers := map[*ast.Object]struct{}{}
for d := range f.dangerObjects {
dangers[d] = struct{}{}
}
for u := range f.unsafeObjects {
dangers[u] = struct{}{}
}
return &Node{
fset: f.fset,
dangerObjects: dangers,
unsafeObjects: f.unsafeObjects,
skipFuncs: f.skipFuncs,
issues: f.issues,
}
}
}
return f
}
// The variadic arguments may start with link and category types,
// and must end with a format string and any arguments.
// It returns the new Problem.
//nolint:interfacer
func (f *Node) errorf(n ast.Node, format string, args ...interface{}) {
pos := f.fset.Position(n.Pos())
f.errorfAt(pos, format, args...)
}
func (f *Node) errorfAt(pos token.Position, format string, args ...interface{}) {
*f.issues = append(*f.issues, result.Issue{
Pos: pos,
Text: fmt.Sprintf(format, args...),
FromLinter: Scopelint{}.Name(),
})
}