tree 2a95db6e9368639d639559962f7642f7f188eee9
parent 0fc224513bfa51ab2efc08057e2ac3897102c338
author Joe Tsai <joetsai@digital-static.net> 1552261248 -0700
committer Joe Tsai <thebrokentoaster@gmail.com> 1552332852 +0000

protogen: drop dependency on golang.org/x/tools/go/ast/astutil

To keep the dependency tree of Go protobufs as small as possible,
avoid depending on astutil. Most of the complexity of astutil.AddNamedImport
was for identifying an existing import block to insert imports into,
which is not relevant for our use-case.

Assuming that we always create a new import block after the package
statement, the logic for doing the AST manipulation is relatively simple.
This re-write properly handles an inline comment after the
package statement, which astutil.AddNamedImport (see golang.org/issue/30724)
currently fails to do.

Change-Id: I894e733aa82a241719b6f0c23de8d2fbfb67b778
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/166522
Reviewed-by: Damien Neil <dneil@google.com>