tools/syz-linter: fix comments check

Turns out ast.Inspect does not visit most comments.
Walk file.Comments manually.

Update #1876

pkg/osutil/osutil_linux.go

@@ -38,7 +38,7 @@ func RemoveAll(dir string) error {
 func SystemMemorySize() uint64 {
 	var info syscall.Sysinfo_t
 	syscall.Sysinfo(&info)
-	return uint64(info.Totalram) //nolint:unconvert
+	return uint64(info.Totalram) // nolint:unconvert
 }
 
 func removeImmutable(fname string) error {

pkg/report/fuchsia.go

@@ -277,9 +277,9 @@ var zirconOopses = append([]*oops{
 	// We should detect just "stopping other cpus" as some kernel crash rather then as "lost connection",
 	// but if we add oops for "stopping other cpus", then it will interfere with other formats,
 	// because "stopping other cpus" usually goes after "ZIRCON KERNEL PANIC", but sometimes before. Mess.
-	//{
+	// {
 	//	[]byte("stopping other cpus"),
-	//},
+	// },
 	{
 		[]byte("welcome to Zircon"),
 		[]oopsFormat{

prog/hints_test.go

@@ -69,7 +69,7 @@ func TestHintsCheckConstArg(t *testing.T) {
 				//		i16 w = (i16) el
 				//		if (w == 0x88) {...}
 				//		i16 other = 0xfffe
-				// 		if (w == other)
+				//		if (w == other)
 				//  }; test8(i8(0x1234));
 				0x34: compSet(0x88, 0x1122, 0xfffffffffffffffe, 0xffffffffffffff0a),
 				// This following args should be iggnored.

prog/mutation_test.go

@@ -280,16 +280,6 @@ mutate4(&(0x7f0000000000)="11223344", 0x4)
 `, `
 mutate4(&(0x7f0000000000)="113344", 0x3)
 `},
-		// Mutate data (insert byte and update size).
-		// TODO: this is not working, because Mutate constantly tends
-		// update addresses and insert mmap's.
-		/*
-					{`
-			mutate4(&(0x7f0000000000)="1122", 0x2)
-			`, `
-			mutate4(&(0x7f0000000000)="112200", 0x3)
-			`},
-		*/
 		// Mutate data (change byte).
 		{`
 mutate4(&(0x7f0000000000)="1122", 0x2)

tools/syz-check/dwarf.go

@@ -19,7 +19,7 @@ func parseKernelObject(obj string) (map[string]*dwarf.StructType, error) {
 	var sections []*elf.Section
 	for _, sec := range file.Sections {
 		// We don't need these for our purposes and dropping them speeds up parsing a lot.
-		//nolint:misspell
+		// nolint:misspell
 		if sec.Name == ".debug_line" || strings.HasPrefix(sec.Name, ".rela.") {
 			continue
 		}

tools/syz-linter/linter.go

@@ -63,9 +63,12 @@ func run(p *analysis.Pass) (interface{}, error) {
 	for _, file := range pass.Files {
 		ast.Inspect(file, func(n ast.Node) bool {
 			switch n := n.(type) {
-			case *ast.Comment:
-				pass.checkMulitlineComments(n)
-				pass.checkCommentSpace(n)
+			case *ast.File:
+				for _, group := range n.Comments {
+					for _, comment := range group.List {
+						pass.checkComment(comment)
+					}
+				}
 			case *ast.BinaryExpr:
 				pass.checkStringLenCompare(n)
 			case *ast.FuncType:
@@ -94,19 +97,17 @@ func (pass *Pass) typ(e ast.Expr) types.Type {
 	return pass.TypesInfo.Types[e].Type
 }
 
-// checkMulitlineComments warns about C++-style multiline comments.
-// We don't use them in the codebase.
-func (pass *Pass) checkMulitlineComments(n *ast.Comment) {
-	if !strings.HasPrefix(n.Text, "/*") {
+// checkComment warns about C++-style multiline comments (we don't use them in the codebase)
+// and about "//nospace", "// 	tabs and spaces" and similar.
+func (pass *Pass) checkComment(n *ast.Comment) {
+	if strings.HasPrefix(n.Text, "/*") {
+		pass.report(n, "Use C-style comments // instead of /* */")
 		return
 	}
-	pass.report(n, "Use C-style comments // instead of /* */")
-}
-
-// checkCommentSpace warns about "//nospace", "// 	tabs and spaces" and similar.
-func (pass *Pass) checkCommentSpace(n *ast.Comment) {
-	if !strings.HasPrefix(n.Text, "//") ||
-		allowedComments.MatchString(n.Text) {
+	if allowedComments.MatchString(n.Text) {
+		return
+	}
+	if strings.HasPrefix(n.Text, "//go:generate") {
 		return
 	}
 	pass.report(n, "Use either //<one-or-more-spaces>comment or //<one-or-more-tabs>comment format for comments")

tools/syz-linter/testdata/src/lintertest/lintertest.go

@@ -32,8 +32,12 @@ func returnString() string { return "foo" }
 //	  Tab and spaces.	// want "Use either //<one-or-more-spaces>comment or //<one-or-more-tabs>comment format for comments"
 // 	Space and tab.		// want "Use either //<one-or-more-spaces>comment or //<one-or-more-tabs>comment format for comments"
 func checkCommentSpace() {
+	// Comment without a dot at the end
+	checkCommentSpace()
 }
 
+//No space.			// want "Use either //<one-or-more-spaces>comment or //<one-or-more-tabs>comment format for comments"
+
 func funcArgsGood(a, b int) (int, int) {
 	return 0, 0
 }