internal/lsp: fix infinite recursion while fixing AST

We were recursing infinitely in cases like this:

switch true {
case true:
	go foo.F<>
}

There were three things that came together to cause this:
1. We recently starting recursively fixing broken go/defer statements.
2. In this case we were failing to swap in the correct ast.Node in for
   the *ast.BadStmt because we were only looking
   for *ast.BlockStmt (and *ast.CaseStmt has no block).
3. After 2), we weren't returning an error so the fix() code thought
   it should recurse.

Fix 2) by using reflection to swap AST nodes in a generic way. Perhaps
a bit overkill in this case, but I happened to have already written
this for an upcoming change, so I just pulled it in to fix this bug.

Fix 3) by returning an error if we fail to swap the AST nodes.

Fixes golang/go#34353.

Change-Id: I17ff1afd52ae165c0ba9de5820dcec4cb7d756cb
Reviewed-on: https://go-review.googlesource.com/c/tools/+/196137
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
3 files changed
tree: 6d94db6a511467f4c518f2d068bd9b61ba0f09d4
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. cover/
  6. go/
  7. godoc/
  8. gopls/
  9. imports/
  10. internal/
  11. playground/
  12. present/
  13. refactor/
  14. .gitattributes
  15. .gitignore
  16. AUTHORS
  17. codereview.cfg
  18. CONTRIBUTING.md
  19. CONTRIBUTORS
  20. go.mod
  21. go.sum
  22. LICENSE
  23. PATENTS
  24. README.md
README.md

Go Tools

This subrepository holds the source for various packages and tools that support the Go programming language.

Some of the tools, godoc and vet for example, are included in binary Go distributions.

Others, including the Go guru and the test coverage tool, can be fetched with go get.

Packages include a type-checker for Go and an implementation of the Static Single Assignment form (SSA) representation for Go programs.

Download/Install

The easiest way to install is to run go get -u golang.org/x/tools/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/tools.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.

The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.