golang.org/x/tools@v0.21.0/go/analysis/passes/shadow/doc.go (about)

     1  // Copyright 2023 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Package shadow defines an Analyzer that checks for shadowed variables.
     6  //
     7  // # Analyzer shadow
     8  //
     9  // shadow: check for possible unintended shadowing of variables
    10  //
    11  // This analyzer check for shadowed variables.
    12  // A shadowed variable is a variable declared in an inner scope
    13  // with the same name and type as a variable in an outer scope,
    14  // and where the outer variable is mentioned after the inner one
    15  // is declared.
    16  //
    17  // (This definition can be refined; the module generates too many
    18  // false positives and is not yet enabled by default.)
    19  //
    20  // For example:
    21  //
    22  //	func BadRead(f *os.File, buf []byte) error {
    23  //		var err error
    24  //		for {
    25  //			n, err := f.Read(buf) // shadows the function variable 'err'
    26  //			if err != nil {
    27  //				break // causes return of wrong value
    28  //			}
    29  //			foo(buf)
    30  //		}
    31  //		return err
    32  //	}
    33  package shadow