go/ast: deprecate MergePackageFiles (it's not used, and buggy)

[gopherbot]

by bgarcia@golang.org:

The parser.ParseComments option to parser.ParseFile
causes ast.MergePackageFiles to create a broken merge.

What steps will reproduce the problem?
  This code reproduces the problem:
  http://play.golang.org/p/63LsxcrpWi
  You can also run godoc with --src option for a package with multiple source files, like strings.

What is the expected output?
  // Package foo does bar and baz.
  package foo

  type string struct{}

  // Foo is a structure.
  type Foo struct{}

  // String outputs Foo in a human-readable way.
  func (f *Foo) String() string { return string{} }

  // Error method for Foo.
  func (f *Foo) Error() string { return f.String() }


What do you see instead?
  package

  // Foo is a structure.
  foo

  type string struct{}

  type Foo struct{}

  // String outputs Foo in a human-readable way.

  // Package foo does bar and baz.

  // Error method for Foo.

  func (f *Foo) String() string { return string{} }

  func (f *Foo) Error() string { return f.String() }

[griesemer]

Comment 3:

ast.MergePackageFiles was implemented with it's former use in godoc in mind; at a time
when tools and the language were still somewhat in flux. godoc is not using
ast.MergePackageFiles anymore, so it's not a blocker for godoc.
Should decide whether to delete or deprecate this function.

Status changed to Accepted.

[bcmills]

Should decide whether to delete or deprecate this function.

It's been 4½ years. We should make that decision, especially in light of Go 2. 🙂