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https://github.com/golang/go
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01f8cd246d
They will be deleted from their current homes once this has landed. Changes made to import paths to make the code compile, and to find errchk in the right place in cmd/vet's Makefile. TODO in a later CL: tidy up vet. R=golang-dev, gri CC=golang-dev https://golang.org/cl/9495043
45 lines
1.1 KiB
Go
45 lines
1.1 KiB
Go
// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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/*
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This file contains the code to check for useless assignments.
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*/
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package main
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import (
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"go/ast"
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"go/token"
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"reflect"
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)
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// TODO: should also check for assignments to struct fields inside methods
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// that are on T instead of *T.
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// checkAssignStmt checks for assignments of the form "<expr> = <expr>".
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// These are almost always useless, and even when they aren't they are usually a mistake.
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func (f *File) checkAssignStmt(stmt *ast.AssignStmt) {
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if !vet("assign") {
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return
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}
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if stmt.Tok != token.ASSIGN {
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return // ignore :=
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}
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if len(stmt.Lhs) != len(stmt.Rhs) {
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// If LHS and RHS have different cardinality, they can't be the same.
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return
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}
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for i, lhs := range stmt.Lhs {
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rhs := stmt.Rhs[i]
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if reflect.TypeOf(lhs) != reflect.TypeOf(rhs) {
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continue // short-circuit the heavy-weight gofmt check
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}
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le := f.gofmt(lhs)
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re := f.gofmt(rhs)
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if le == re {
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f.Warnf(stmt.Pos(), "self-assignment of %s to %s", re, le)
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}
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}
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}
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