Right now, a .proto file can have a line like

option go_package = "foo";

which means that the generated .pb.go file should have a package foo statement.

I am proposing to overload this option with two new possible syntaxes:

option go_package = "github.com/example/foo";

This means that generated code should be dropped into the github.com/example/foo directory (relative to whatever is passed to protoc's --go_out flag), overriding the default behaviour of matching the path to the .proto file. It also means the .pb.go file should have a package foo statement.

option go_package = "github.com/example/foo;bar";

This means the same as the previous syntax, but additionally means that the .pb.go file should have a package bar statement, for the rare cases where people want the package name to differ from the final path component of the import path.

This would hopefully mean that far fewer M parameters need to be passed through the --go_out flag. It would subsume #137 and maybe #63.

Thoughts? Opinions?

@robpike @zellyn @mwitkow @awalterschulze @peter-edge @tamird