Add staticcheck tool

vendor/honnef.co/go/tools/staticcheck/sa6000/sa6000.go

@@ -0,0 +1,57 @@
+package sa6000
+
+import (
+	"fmt"
+
+	"honnef.co/go/tools/analysis/callcheck"
+	"honnef.co/go/tools/analysis/lint"
+	"honnef.co/go/tools/go/ir"
+	"honnef.co/go/tools/go/ir/irutil"
+	"honnef.co/go/tools/internal/passes/buildir"
+
+	"golang.org/x/tools/go/analysis"
+)
+
+var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
+	Analyzer: &analysis.Analyzer{
+		Name:     "SA6000",
+		Requires: []*analysis.Analyzer{buildir.Analyzer},
+		Run:      callcheck.Analyzer(rules),
+	},
+	Doc: &lint.RawDocumentation{
+		Title:    `Using \'regexp.Match\' or related in a loop, should use \'regexp.Compile\'`,
+		Since:    "2017.1",
+		Severity: lint.SeverityWarning,
+		MergeIf:  lint.MergeIfAny,
+	},
+})
+
+var Analyzer = SCAnalyzer.Analyzer
+
+var rules = map[string]callcheck.Check{
+	"regexp.Match":       check("regexp.Match"),
+	"regexp.MatchReader": check("regexp.MatchReader"),
+	"regexp.MatchString": check("regexp.MatchString"),
+}
+
+func check(name string) callcheck.Check {
+	return func(call *callcheck.Call) {
+		if callcheck.ExtractConst(call.Args[0].Value) == nil {
+			return
+		}
+		if !isInLoop(call.Instr.Block()) {
+			return
+		}
+		call.Invalid(fmt.Sprintf("calling %s in a loop has poor performance, consider using regexp.Compile", name))
+	}
+}
+
+func isInLoop(b *ir.BasicBlock) bool {
+	sets := irutil.FindLoops(b.Parent())
+	for _, set := range sets {
+		if set.Has(b) {
+			return true
+		}
+	}
+	return false
+}