draft: syscall support

pkg/analyzer/analyzer.go

@@ -26,6 +26,7 @@ const (
 	SQLIsolationLevelFlag  = "sql-isolation-level"
 	TLSSignatureSchemeFlag = "tls-signature-scheme"
 	ConstantKindFlag       = "constant-kind"
+	SyscallFileModeFlag    = "syscall-file-mode"
 	SyslogPriorityFlag     = "syslog-priority"
 )
 
@@ -53,6 +54,7 @@ func flags() flag.FlagSet {
 	flags.Bool(SQLIsolationLevelFlag, false, "suggest the use of sql.LevelXX.String()")
 	flags.Bool(TLSSignatureSchemeFlag, false, "suggest the use of tls.SignatureScheme.String()")
 	flags.Bool(ConstantKindFlag, false, "suggest the use of constant.Kind.String()")
+	flags.Bool(SyscallFileModeFlag, false, "suggest the use of syscall constants for file mode")
 	flags.Bool(SyslogPriorityFlag, false, "[DEPRECATED] suggest the use of syslog.Priority")
 	return *flags
 }
@@ -221,6 +223,23 @@ func funArgs(pass *analysis.Pass, x *ast.Ident, fun *ast.SelectorExpr, args []as
 				checkHTTPMethod(pass, basicLit)
 			}
 		}
+	case "os":
+		if !lookupFlag(pass, SyscallFileModeFlag) {
+			return
+		}
+
+		switch fun.Sel.Name {
+		case "Chmod", "Mkdir", "MkdirAll":
+
+			if basicLit := getBasicLitFromArgs(args, 2, 1, token.INT); basicLit != nil {
+				checkFileModeMethod(pass, basicLit)
+			}
+		case "OpenFile", "WriteFile":
+			if basicLit := getBasicLitFromArgs(args, 3, 2, token.INT); basicLit != nil {
+				checkFileModeMethod(pass, basicLit)
+			}
+		}
+
 	case "syslog":
 		if !lookupFlag(pass, SyslogPriorityFlag) {
 			return
@@ -359,6 +378,14 @@ func lookupFlag(pass *analysis.Pass, name string) bool {
 	return pass.Analyzer.Flags.Lookup(name).Value.(flag.Getter).Get().(bool)
 }
 
+func checkFileModeMethod(pass *analysis.Pass, basicLit *ast.BasicLit) {
+	currentVal := getBasicLitValue(basicLit)
+
+	if newVal, ok := mapping.FileMode[currentVal]; ok {
+		report(pass, basicLit, currentVal, newVal)
+	}
+}
+
 func checkHTTPMethod(pass *analysis.Pass, basicLit *ast.BasicLit) {
 	currentVal := getBasicLitValue(basicLit)
 

pkg/analyzer/analyzer_test.go

@@ -17,6 +17,7 @@ var flags = []string{
 	analyzer.SQLIsolationLevelFlag,
 	analyzer.TLSSignatureSchemeFlag,
 	analyzer.ConstantKindFlag,
+	analyzer.SyscallFileModeFlag,
 }
 
 func TestUseStdlibVars(t *testing.T) {
@@ -38,6 +39,7 @@ func TestUseStdlibVars(t *testing.T) {
 		{dir: "a/sql"},
 		{dir: "a/tls"},
 		{dir: "a/constant"},
+		{dir: "a/os"},
 	}
 
 	for _, test := range testCases {

pkg/analyzer/internal/gen.go

@@ -121,6 +121,13 @@ func main() {
 			goldenTemplateName: "test-issue89.go.golden.tmpl",
 			fileName:           "pkg/analyzer/testdata/src/a/http/issue89.go",
 		},
+		{
+			mapping:            mapping.FileMode,
+			packageName:        "os_test",
+			templateName:       "test-osfilemode.go.tmpl",
+			goldenTemplateName: "test-osfilemode.go.golden.tmpl",
+			fileName:           "pkg/analyzer/testdata/src/a/os/filemode.go",
+		},
 	}
 
 	for _, operation := range operations {

pkg/analyzer/internal/mapping/mapping.go

@@ -114,6 +114,19 @@ var HTTPStatusCode = map[string]string{
 	strconv.Itoa(http.StatusNetworkAuthenticationRequired): "http.StatusNetworkAuthenticationRequired",
 }
 
+var FileMode = map[string]string{
+	"0o777": "syscall.S_IRWXU | syscall.S_IRWXG | syscall.S_IRWXO",
+	"0o775": "syscall.S_IRWXU | syscall.S_IRWXG | syscall.S_IROTH | syscall.S_IXOTH",
+	"0o755": "syscall.S_IRWXU | syscall.S_IRGRP | syscall.S_IXGRP | syscall.S_IROTH | syscall.S_IXOTH",
+	"0o700": "syscall.S_IRWXU",
+	"0o666": "syscall.S_IRUSR | syscall.S_IWUSR | syscall.S_IRGRP | syscall.S_IWGRP | syscall.S_IROTH | syscall.S_IWOTH",
+	"0o644": "syscall.S_IRUSR | syscall.S_IWUSR | syscall.S_IRGRP | syscall.S_IROTH",
+	"0o600": "syscall.S_IRUSR | syscall.S_IWUSR",
+	"0o440": "syscall.S_IRUSR | syscall.S_IRGRP",
+	"0o444": "syscall.S_IRUSR | syscall.S_IRGRP | syscall.S_IROTH",
+	"0o400": "syscall.S_IRUSR",
+}
+
 var RPCDefaultPath = map[string]string{
 	rpc.DefaultRPCPath:   "rpc.DefaultRPCPath",
 	rpc.DefaultDebugPath: "rpc.DefaultDebugPath",

pkg/analyzer/internal/template/test-osfilemode.go.golden.tmpl

@@ -0,0 +1,18 @@
+// Code generated by usestdlibvars, DO NOT EDIT.
+
+package {{ .PackageName }}
+
+import "os"
+
+// var f *os.File
+
+var (
+{{- range $key, $value := .Mapping }}
+	_, _ = os.OpenFile("file.txt", os.O_CREATE, {{ $value }}) // want `"{{ quoteMeta $key }}" can be replaced by {{ quoteMeta $value }}`
+	_ = os.WriteFile("file.txt", nil, {{ $value }}) // want `"{{ quoteMeta $key }}" can be replaced by {{ quoteMeta $value }}`
+	_ = os.Chmod("file.txt", {{ $value }}) // want `"{{ quoteMeta $key }}" can be replaced by {{ quoteMeta $value }}`
+	_ = os.Mkdir("folder", {{ $value }}) // want `"{{ quoteMeta $key }}" can be replaced by {{ quoteMeta $value }}`
+	_ = os.MkdirAll("folder", {{ $value }}) // want `"{{ quoteMeta $key }}" can be replaced by {{ quoteMeta $value }}`
+{{- end }}
+)
+

pkg/analyzer/internal/template/test-osfilemode.go.tmpl

@@ -0,0 +1,18 @@
+// Code generated by usestdlibvars, DO NOT EDIT.
+
+package {{ .PackageName }}
+
+import "os"
+
+// var f *os.File
+
+var (
+{{- range $key, $value := .Mapping }}
+	_, _ = os.OpenFile("file.txt", os.O_CREATE, {{ $key }}) // want `"{{ quoteMeta $key }}" can be replaced by {{ quoteMeta $value }}`
+	_ = os.WriteFile("file.txt", nil, {{ $key }}) // want `"{{ quoteMeta $key }}" can be replaced by {{ quoteMeta $value }}`
+	_ = os.Chmod("file.txt", {{ $key }}) // want `"{{ quoteMeta $key }}" can be replaced by {{ quoteMeta $value }}`
+	_ = os.Mkdir("folder", {{ $key }}) // want `"{{ quoteMeta $key }}" can be replaced by {{ quoteMeta $value }}`
+	_ = os.MkdirAll("folder", {{ $key }}) // want `"{{ quoteMeta $key }}" can be replaced by {{ quoteMeta $value }}`
+{{- end }}
+)
+