fix: skip process sys imports and their function calls (cloudwego#4)

Author: welkeyever

src/compress/golang/plugin/go_ast.go

@@ -41,6 +41,7 @@ func (p *goParser) parseFile(filePath string) ([]Function, error) {
 
 	thirdPartyImports := make(map[string]struct{})
 	projectImports := make(map[string]string)
+	sysImports := make(map[string]string)
 	for _, imp := range f.Imports {
 		importPath := imp.Path.Value[1 : len(imp.Path.Value)-1] // remove the quotes
 		importBaseName := filepath.Base(importPath)
@@ -53,6 +54,10 @@ func (p *goParser) parseFile(filePath string) ([]Function, error) {
 
 		isSysPkg := !strings.Contains(strings.Split(importPath, "/")[0], ".")
 
+		if isSysPkg {
+			sysImports[importAlias] = importPath
+		}
+
 		// Ignoring golang standard libraries（like net/http）
 		if !isSysPkg {
 			// Distinguish between project packages and third party packages
@@ -113,6 +118,11 @@ func (p *goParser) parseFile(filePath string) ([]Function, error) {
 							return true
 						}
 
+						// skip sys imports
+						if _, ok = sysImports[x.(*ast.Ident).Name]; ok {
+							return true
+						}
+
 						methodCalls = append(methodCalls, funcName)
 						return true
 					case *ast.Ident: