fixed some bugs related to additional linkname corner cases (#210)

main.go

@@ -609,6 +609,9 @@ func (tf *transformer) handleDirectives(comments []string) {
 		if pkg == "runtime" && strings.HasPrefix(name, "cgo") {
 			continue // ignore cgo-generated linknames
 		}
+		if !isPrivate(pkg) {
+			continue // ignore non-private symbols
+		}
 		listedPkg, ok := buildInfo.imports[pkg]
 		if !ok {
 			continue // probably a made up symbol name
@@ -620,9 +623,14 @@ func (tf *transformer) handleDirectives(comments []string) {
 
 		// The name exists and was obfuscated; replace the
 		// comment with the obfuscated name.
-		obfName := hashWith(listedPkg.actionID, name)
-		fields[2] = pkg + "." + obfName
-		comments[i] = strings.Join(fields, " ")
+		if token.IsExported(name) {
+			obfName := hashWith(listedPkg.actionID, name)
+			fields[2] = pkg + "." + obfName
+			comments[i] = strings.Join(fields, " ")
+		} else if obfName, ok := tf.privateNameMap[fields[2]]; ok {
+			fields[2] = pkg + "." + obfName
+			comments[i] = strings.Join(fields, " ")
+		}
 	}
 }
 

testdata/scripts/linkname.txt

@@ -20,6 +20,7 @@ go 1.15
 package main
 
 import (
+	_ "os/exec"
 	_ "strings"
 	_ "unsafe"
 
@@ -30,6 +31,10 @@ import (
 //go:linkname byteIndex strings.IndexByte
 func byteIndex(s string, c byte) int
 
+// A linkname to an external non-garbled non-exported func.
+//go:linkname interfaceEqual os/exec.interfaceEqual
+func interfaceEqual(a, b interface{}) bool
+
 // A linkname to an external garbled func.
 //go:linkname garbledFunc test/main/imported.GarbledFuncImpl
 func garbledFunc() string
@@ -40,6 +45,7 @@ func renamedFunc() string
 
 func main() {
 	println(byteIndex("01234", '3'))
+	println(interfaceEqual("Sephiroth", 7))
 	println(garbledFunc())
 	println(renamedFunc())
 }
@@ -60,5 +66,6 @@ func renamedFunc() string {
 }
 -- main.stderr --
 3
+false
 garbled func
 renamed func