sa5011

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• Variables

Variables

var Analyzer = SCAnalyzer.Analyzer

var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
	Analyzer: &analysis.Analyzer{
		Name:     "SA5011",
		Run:      run,
		Requires: []*analysis.Analyzer{buildir.Analyzer},
	},
	Doc: &lint.RawDocumentation{
		Title: `Possible nil pointer dereference`,

		Text: `A pointer is being dereferenced unconditionally, while
also being checked against nil in another place. This suggests that
the pointer may be nil and dereferencing it may panic. This is
commonly a result of improperly ordered code or missing return
statements. Consider the following examples:

    func fn(x *int) {
        fmt.Println(*x)

        // This nil check is equally important for the previous dereference
        if x != nil {
            foo(*x)
        }
    }

    func TestFoo(t *testing.T) {
        x := compute()
        if x == nil {
            t.Errorf("nil pointer received")
        }

        // t.Errorf does not abort the test, so if x is nil, the next line will panic.
        foo(*x)
    }

Staticcheck tries to deduce which functions abort control flow.
For example, it is aware that a function will not continue
execution after a call to \'panic\' or \'log.Fatal\'. However, sometimes
this detection fails, in particular in the presence of
conditionals. Consider the following example:

    func Log(msg string, level int) {
        fmt.Println(msg)
        if level == levelFatal {
            os.Exit(1)
        }
    }

    func Fatal(msg string) {
        Log(msg, levelFatal)
    }

    func fn(x *int) {
        if x == nil {
            Fatal("unexpected nil pointer")
        }
        fmt.Println(*x)
    }

Staticcheck will flag the dereference of \'x\', even though it is perfectly
safe. Staticcheck is not able to deduce that a call to
Fatal will exit the program. For the time being, the easiest
workaround is to modify the definition of Fatal like so:

    func Fatal(msg string) {
        Log(msg, levelFatal)
        panic("unreachable")
    }

We also hard-code functions from common logging packages such as
logrus. Please file an issue if we're missing support for a
popular package.`,
		Since:    "2020.1",
		Severity: lint.SeverityWarning,
		MergeIf:  lint.MergeIfAny,
	},
})