reflect: record PkgPath of StructOf arguments

Fixes #36190
Fixes #36191

Change-Id: I1213ef37b6595af63dbe202a8ade65741caf1356
Reviewed-on: https://go-review.googlesource.com/c/go/+/212001
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/reflect/all_test.go b/src/reflect/all_test.go
index 7443666fa68dbeb114cf959016b5f27ad49ccb2c..5f2f60017481038d4886a666c59e6694a3bc0347 100644 (file)
--- a/src/reflect/all_test.go
+++ b/src/reflect/all_test.go
@@ -4853,6 +4853,9 @@ func TestStructOfExportRules(t *testing.T) {
                        if exported != test.exported {
                                t.Errorf("test-%d: got exported=%v want exported=%v", i, exported, test.exported)
                        }
+                       if field.PkgPath != test.field.PkgPath {
+                               t.Errorf("test-%d: got PkgPath=%q want pkgPath=%q", i, field.PkgPath, test.field.PkgPath)
+                       }
                })
        }
 }
@@ -5308,6 +5311,24 @@ func TestStructOfTooManyFields(t *testing.T) {
        }
 }
 
+func TestStructOfDifferentPkgPath(t *testing.T) {
+       fields := []StructField{
+               {
+                       Name:    "f1",
+                       PkgPath: "p1",
+                       Type:    TypeOf(int(0)),
+               },
+               {
+                       Name:    "f2",
+                       PkgPath: "p2",
+                       Type:    TypeOf(int(0)),
+               },
+       }
+       shouldPanic(func() {
+               StructOf(fields)
+       })
+}
+
 func TestChanOf(t *testing.T) {
        // check construction and use of type not in binary
        type T string

diff --git a/src/reflect/type.go b/src/reflect/type.go
index fc31e31eee7314962a8ad820045716955f0fb203..cd8522d9045c1bd194a0762cb6388c019778fe47 100644 (file)
--- a/src/reflect/type.go
+++ b/src/reflect/type.go
@@ -2371,6 +2371,7 @@ func StructOf(fields []StructField) Type {
 
        lastzero := uintptr(0)
        repr = append(repr, "struct {"...)
+       pkgpath := ""
        for i, field := range fields {
                if field.Name == "" {
                        panic("reflect.StructOf: field " + strconv.Itoa(i) + " has no name")
@@ -2381,11 +2382,18 @@ func StructOf(fields []StructField) Type {
                if field.Type == nil {
                        panic("reflect.StructOf: field " + strconv.Itoa(i) + " has no type")
                }
-               f := runtimeStructField(field)
+               f, fpkgpath := runtimeStructField(field)
                ft := f.typ
                if ft.kind&kindGCProg != 0 {
                        hasGCProg = true
                }
+               if fpkgpath != "" {
+                       if pkgpath == "" {
+                               pkgpath = fpkgpath
+                       } else if pkgpath != fpkgpath {
+                               panic("reflect.Struct: fields with different PkgPath " + pkgpath + " and " + fpkgpath)
+                       }
+               }
 
                // Update string and hash
                name := f.name.name()
@@ -2617,6 +2625,9 @@ func StructOf(fields []StructField) Type {
        prototype := *(**structType)(unsafe.Pointer(&istruct))
        *typ = *prototype
        typ.fields = fs
+       if pkgpath != "" {
+               typ.pkgPath = newName(pkgpath, "", false)
+       }
 
        // Look in cache.
        if ts, ok := structLookupCache.m.Load(hash); ok {
@@ -2741,7 +2752,10 @@ func StructOf(fields []StructField) Type {
        return addToCache(&typ.rtype)
 }
 
-func runtimeStructField(field StructField) structField {
+// runtimeStructField takes a StructField value passed to StructOf and
+// returns both the corresponding internal representation, of type
+// structField, and the pkgpath value to use for this field.
+func runtimeStructField(field StructField) (structField, string) {
        if field.Anonymous && field.PkgPath != "" {
                panic("reflect.StructOf: field \"" + field.Name + "\" is anonymous but has PkgPath set")
        }
@@ -2762,11 +2776,12 @@ func runtimeStructField(field StructField) structField {
        }
 
        resolveReflectType(field.Type.common()) // install in runtime
-       return structField{
+       f := structField{
                name:        newName(field.Name, string(field.Tag), exported),
                typ:         field.Type.common(),
                offsetEmbed: offsetEmbed,
        }
+       return f, field.PkgPath
 }
 
 // typeptrdata returns the length in bytes of the prefix of t