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|
package main
import (
"go/ast"
"go/token"
"go/types"
"reflect"
"strings"
"golang.org/x/tools/go/analysis"
"golang.org/x/tools/go/analysis/multichecker"
)
type indirectCalls struct {
methods map[token.Pos]string
functions map[string]token.Pos
}
var PanicAnalyzer = &analysis.Analyzer{
Name: "panic",
Doc: "finds goroutines that do not initialize the panic handler",
Run: runPanic,
ResultType: reflect.TypeOf(&indirectCalls{}),
}
var PanicIndirectAnalyzer = &analysis.Analyzer{
Name: "panicindirect",
Doc: "finds functions called as goroutines that do not initialize the panic handler",
Run: runPanicIndirect,
Requires: []*analysis.Analyzer{PanicAnalyzer},
}
func runPanic(pass *analysis.Pass) (interface{}, error) {
var calls indirectCalls
calls.methods = make(map[token.Pos]string)
calls.functions = make(map[string]token.Pos)
for _, file := range pass.Files {
ast.Inspect(file, func(n ast.Node) bool {
g, ok := n.(*ast.GoStmt)
if !ok {
return true
}
var block *ast.BlockStmt
expr := g.Call.Fun
if e, ok := expr.(*ast.ParenExpr); ok {
expr = e.X
}
switch e := expr.(type) {
case *ast.FuncLit:
block = e.Body
case *ast.SelectorExpr:
sel, ok := pass.TypesInfo.Selections[e]
if ok {
f, ok := sel.Obj().(*types.Func)
if ok {
calls.methods[f.Pos()] = f.Name()
}
}
case *ast.Ident:
block = inlineFuncBody(e)
if block == nil {
calls.functions[e.Name] = e.NamePos
}
}
if block == nil {
return true
}
if !isPanicHandlerInstall(block.List[0]) {
path := pass.Fset.File(block.Pos()).Name()
if !strings.HasSuffix(path, "_test.go") {
pass.Report(panicDiag(block.Pos()))
}
}
return true
})
}
return &calls, nil
}
func runPanicIndirect(pass *analysis.Pass) (interface{}, error) {
calls := pass.ResultOf[PanicAnalyzer].(*indirectCalls)
for _, file := range pass.Files {
if strings.HasSuffix(file.Name.Name, "_test") {
continue
}
for _, decl := range file.Decls {
if f, ok := decl.(*ast.FuncDecl); ok {
if _, ok := calls.methods[f.Name.Pos()]; ok {
delete(calls.methods, f.Name.Pos())
} else if _, ok := calls.functions[f.Name.Name]; ok {
delete(calls.functions, f.Name.Name)
} else {
continue
}
if !isPanicHandlerInstall(f.Body.List[0]) {
path := pass.Fset.File(f.Body.Pos()).Name()
if !strings.HasSuffix(path, "_test.go") {
pass.Report(panicDiag(f.Body.Pos()))
}
}
}
}
}
return nil, nil
}
func panicDiag(pos token.Pos) analysis.Diagnostic {
return analysis.Diagnostic{
Pos: pos,
Category: "panic",
Message: "missing defer log.PanicHandler() as first statement",
}
}
func inlineFuncBody(s *ast.Ident) *ast.BlockStmt {
if s.Obj == nil || s.Obj.Decl == nil {
return nil
}
d, ok := s.Obj.Decl.(*ast.AssignStmt)
if !ok {
return nil
}
for _, r := range d.Rhs {
if f, ok := r.(*ast.FuncLit); ok {
return f.Body
}
}
return nil
}
func isPanicHandlerInstall(stmt ast.Stmt) bool {
d, ok := stmt.(*ast.DeferStmt)
if !ok {
return false
}
s, ok := d.Call.Fun.(*ast.SelectorExpr)
if !ok {
return false
}
i, ok := s.X.(*ast.Ident)
if !ok {
return false
}
return i.Name == "log" && s.Sel.Name == "PanicHandler"
}
func main() {
multichecker.Main(
PanicAnalyzer,
PanicIndirectAnalyzer,
)
}
|
