equal: Fix handling of nil values #56
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
misberner
commented
Aug 17, 2022
Comment on lines
+225
to
+228
| p.P(`p = &`, p.QualifiedGoIdent(msg.GoIdent), `{}`) | ||
| p.P(`}`) | ||
| p.P(`if q == nil {`) | ||
| p.P(`q = &`, p.QualifiedGoIdent(msg.GoIdent), `{}`) |
There was a problem hiding this comment.
Not super happy with allocating values here, but unfortunately it's not very easy to introduce package-private helper variables on the fly for types where this is needed. Also, nil values in non-nullable contexts should be an exception.
There was a problem hiding this comment.
This does not allocate values. They stay in the stack. :)
./test_messages_proto2_vtproto.pb.go:1212:9: &TestAllTypesProto2_NestedMessage{} does not escape
./test_messages_proto2_vtproto.pb.go:1215:9: &TestAllTypesProto2_NestedMessage{} does not escape
./test_messages_proto2_vtproto.pb.go:1229:9: &ForeignMessageProto2{} does not escape
./test_messages_proto2_vtproto.pb.go:1232:9: &ForeignMessageProto2{} does not escape
vmg
approved these changes
Aug 17, 2022
Comment on lines
+225
to
+228
| p.P(`p = &`, p.QualifiedGoIdent(msg.GoIdent), `{}`) | ||
| p.P(`}`) | ||
| p.P(`if q == nil {`) | ||
| p.P(`q = &`, p.QualifiedGoIdent(msg.GoIdent), `{}`) |
There was a problem hiding this comment.
This does not allocate values. They stay in the stack. :)
./test_messages_proto2_vtproto.pb.go:1212:9: &TestAllTypesProto2_NestedMessage{} does not escape
./test_messages_proto2_vtproto.pb.go:1215:9: &TestAllTypesProto2_NestedMessage{} does not escape
./test_messages_proto2_vtproto.pb.go:1229:9: &ForeignMessageProto2{} does not escape
./test_messages_proto2_vtproto.pb.go:1232:9: &ForeignMessageProto2{} does not escape
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The current
equalimplementation generates code that recognizes anilmessage as being equal to an empty message of the same type. However, this is not howproto.Equalworks, where anilmessage is only equal to anothernilmessage of the same type.A complication arises from the fact that
niland empty message values need to be treated as equal in certain contexts - slice elements, map values, oneofs. This is the same principle as the one described in #52, only applied to messages instead of byte slices.This PR solves this by propagating the
nullable(i.e., presence) information to the code generator for comparing message values, and substitutingnilvalues for empty ones for non-nullable values.