Display diagnostic message for each conversion error.

Also, use better names for the error handling entities.

Bug: 204062171
Test: manual
Change-Id: I65869120ed08fc40d9ec6267c882e53aaedde9ed

mk2rbc/cmd/mk2rbc.go

@@ -81,7 +81,7 @@ func init() {
 
 var backupSuffix string
 var tracedVariables []string
-var errorLogger = errorsByType{data: make(map[string]datum)}
+var errorLogger = errorSink{data: make(map[string]datum)}
 var makefileFinder = &LinuxMakefileFinder{}
 var versionDefaultsMk = filepath.Join("build", "make", "core", "version_defaults.mk")
 
@@ -339,9 +339,7 @@ func convertOne(mkFile string) (ok bool) {
 		WarnPartialSuccess: !*noWarn,
 		SourceFS:           os.DirFS(*rootDir),
 		MakefileFinder:     makefileFinder,
-	}
-	if *errstat {
-		mk2starRequest.ErrorLogger = errorLogger
+		ErrorLogger:        errorLogger,
 	}
 	ss, err := mk2rbc.Convert(mk2starRequest)
 	if err != nil {
@@ -456,10 +454,8 @@ func printStats() {
 			}
 		}
 	}
-	if *verbose {
-		fmt.Fprintf(os.Stderr, "%-16s%5d\n", "Succeeded:", nOk)
-		fmt.Fprintf(os.Stderr, "%-16s%5d\n", "Partial:", nPartial)
-		fmt.Fprintf(os.Stderr, "%-16s%5d\n", "Failed:", nFailed)
+	if *verbose && (nPartial > 0 || nFailed > 0) {
+		fmt.Fprintln(os.Stderr, "Succeeded: ", nOk, " Partial: ", nPartial, " Failed: ", nFailed)
 	}
 }
 
@@ -468,11 +464,18 @@ type datum struct {
 	formattingArgs []string
 }
 
-type errorsByType struct {
+type errorSink struct {
 	data map[string]datum
 }
 
-func (ebt errorsByType) NewError(message string, node parser.Node, args ...interface{}) {
+func (ebt errorSink) NewError(sourceFile string, sourceLine int, node parser.Node, message string, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, "%s:%d ", sourceFile, sourceLine)
+	fmt.Fprintf(os.Stderr, message, args...)
+	fmt.Fprintln(os.Stderr)
+	if !*errstat {
+		return
+	}
+
 	v, exists := ebt.data[message]
 	if exists {
 		v.count++
@@ -497,7 +500,7 @@ func (ebt errorsByType) NewError(message string, node parser.Node, args ...inter
 	ebt.data[message] = v
 }
 
-func (ebt errorsByType) printStatistics() {
+func (ebt errorSink) printStatistics() {
 	if len(ebt.data) > 0 {
 		fmt.Fprintln(os.Stderr, "Error counts:")
 	}