bpf2go: avoid os.Rename, instead compiling to the desired object file name

Author: yonch

cmd/bpf2go/main.go

@@ -417,30 +417,32 @@ func (b2g *bpf2go) convert(tgt gen.Target, goarches gen.GoArches) (err error) {
 	var allDeps []dependency
 	var tmpObjFileNames []string
 	for _, source := range b2g.sourceFiles {
-		deps, err := b2g.compileOne(tgt, cwd, source, objFileName)
-		if err != nil {
-			return err
-		}
-
-		if len(deps) > 0 {
-			// There is always at least a dependency for the main file.
-			deps[0].file = goFileName
-			allDeps = append(allDeps, deps...)
-		}
-
-		// For multiple source files, we need to move the compiled object to a temporary file
+		// Determine the target object file name
+		var targetObjFileName string
 		if len(b2g.sourceFiles) > 1 {
+			// For multiple source files, use a temporary file
 			tmpObj, err := os.CreateTemp("", filepath.Base(source))
 			if err != nil {
 				return fmt.Errorf("create temporary object file: %w", err)
 			}
 			tmpObj.Close()
 			defer os.Remove(tmpObj.Name())
+			targetObjFileName = tmpObj.Name()
+			tmpObjFileNames = append(tmpObjFileNames, targetObjFileName)
+		} else {
+			// For single source file, use the final object file name
+			targetObjFileName = objFileName
+		}
 
-			if err := os.Rename(objFileName, tmpObj.Name()); err != nil {
-				return fmt.Errorf("move object file: %w", err)
-			}
-			tmpObjFileNames = append(tmpObjFileNames, tmpObj.Name())
+		deps, err := b2g.compileOne(tgt, cwd, source, targetObjFileName)
+		if err != nil {
+			return err
+		}
+
+		if len(deps) > 0 {
+			// There is always at least a dependency for the main file.
+			deps[0].file = goFileName
+			allDeps = append(allDeps, deps...)
 		}
 	}