88 lines
3.1 KiB
Go
88 lines
3.1 KiB
Go
|
package s1030
|
|||
|
|
|
|||
|
|
import (
|
|||
|
|
"fmt"
|
|||
|
|
"go/ast"
|
|||
|
|
"go/types"
|
|||
|
|
|
|||
|
|
"honnef.co/go/tools/analysis/code"
|
|||
|
|
"honnef.co/go/tools/analysis/edit"
|
|||
|
|
"honnef.co/go/tools/analysis/facts/generated"
|
|||
|
|
"honnef.co/go/tools/analysis/lint"
|
|||
|
|
"honnef.co/go/tools/analysis/report"
|
|||
|
|
"honnef.co/go/tools/pattern"
|
|||
|
|
|
|||
|
|
"golang.org/x/tools/go/analysis"
|
|||
|
|
"golang.org/x/tools/go/analysis/passes/inspect"
|
|||
|
|
"golang.org/x/tools/go/ast/inspector"
|
|||
|
|
)
|
|||
|
|
|
|||
|
|
var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
|
|||
|
|
Analyzer: &analysis.Analyzer{
|
|||
|
|
Name: "S1030",
|
|||
|
|
Run: run,
|
|||
|
|
Requires: []*analysis.Analyzer{inspect.Analyzer, generated.Analyzer},
|
|||
|
|
},
|
|||
|
|
Doc: &lint.RawDocumentation{
|
|||
|
|
Title: `Use \'bytes.Buffer.String\' or \'bytes.Buffer.Bytes\'`,
|
|||
|
|
Text: `\'bytes.Buffer\' has both a \'String\' and a \'Bytes\' method. It is almost never
|
|||
|
|
necessary to use \'string(buf.Bytes())\' or \'[]byte(buf.String())\' – simply
|
|||
|
|
use the other method.
|
|||
|
|
|
|||
|
|
The only exception to this are map lookups. Due to a compiler optimization,
|
|||
|
|
\'m[string(buf.Bytes())]\' is more efficient than \'m[buf.String()]\'.
|
|||
|
|
`,
|
|||
|
|
Since: "2017.1",
|
|||
|
|
MergeIf: lint.MergeIfAny,
|
|||
|
|
},
|
|||
|
|
})
|
|||
|
|
|
|||
|
|
var Analyzer = SCAnalyzer.Analyzer
|
|||
|
|
|
|||
|
|
var (
|
|||
|
|
checkBytesBufferConversionsQ = pattern.MustParse(`(CallExpr _ [(CallExpr sel@(SelectorExpr recv _) [])])`)
|
|||
|
|
checkBytesBufferConversionsRs = pattern.MustParse(`(CallExpr (SelectorExpr recv (Ident "String")) [])`)
|
|||
|
|
checkBytesBufferConversionsRb = pattern.MustParse(`(CallExpr (SelectorExpr recv (Ident "Bytes")) [])`)
|
|||
|
|
)
|
|||
|
|
|
|||
|
|
func run(pass *analysis.Pass) (any, error) {
|
|||
|
|
if pass.Pkg.Path() == "bytes" || pass.Pkg.Path() == "bytes_test" {
|
|||
|
|
// The bytes package can use itself however it wants
|
|||
|
|
return nil, nil
|
|||
|
|
}
|
|||
|
|
fn := func(c inspector.Cursor) {
|
|||
|
|
node := c.Node()
|
|||
|
|
m, ok := code.Match(pass, checkBytesBufferConversionsQ, node)
|
|||
|
|
if !ok {
|
|||
|
|
return
|
|||
|
|
}
|
|||
|
|
call := node.(*ast.CallExpr)
|
|||
|
|
sel := m.State["sel"].(*ast.SelectorExpr)
|
|||
|
|
|
|||
|
|
typ := pass.TypesInfo.TypeOf(call.Fun)
|
|||
|
|
if types.Unalias(typ) == types.Universe.Lookup("string").Type() && code.IsCallTo(pass, call.Args[0], "(*bytes.Buffer).Bytes") {
|
|||
|
|
if _, ok := c.Parent().Node().(*ast.IndexExpr); ok {
|
|||
|
|
// Don't flag m[string(buf.Bytes())] – thanks to a
|
|||
|
|
// compiler optimization, this is actually faster than
|
|||
|
|
// m[buf.String()]
|
|||
|
|
return
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
report.Report(pass, call, fmt.Sprintf("should use %v.String() instead of %v", report.Render(pass, sel.X), report.Render(pass, call)),
|
|||
|
|
report.FilterGenerated(),
|
|||
|
|
report.Fixes(edit.Fix("Simplify conversion", edit.ReplaceWithPattern(pass.Fset, node, checkBytesBufferConversionsRs, m.State))))
|
|||
|
|
} else if typ, ok := types.Unalias(typ).(*types.Slice); ok &&
|
|||
|
|
types.Unalias(typ.Elem()) == types.Universe.Lookup("byte").Type() &&
|
|||
|
|
code.IsCallTo(pass, call.Args[0], "(*bytes.Buffer).String") {
|
|||
|
|
report.Report(pass, call, fmt.Sprintf("should use %v.Bytes() instead of %v", report.Render(pass, sel.X), report.Render(pass, call)),
|
|||
|
|
report.FilterGenerated(),
|
|||
|
|
report.Fixes(edit.Fix("Simplify conversion", edit.ReplaceWithPattern(pass.Fset, node, checkBytesBufferConversionsRb, m.State))))
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
}
|
|||
|
|
for c := range code.Cursor(pass).Preorder((*ast.CallExpr)(nil)) {
|
|||
|
|
fn(c)
|
|||
|
|
}
|
|||
|
|
return nil, nil
|
|||
|
|
}
|