Emacs flymake-mode for the Go programming language

The goflymake program is a wrapper around the go tool to provide Emacs flymake style syntax checking for golang source files within multi-file packages and _test.go files. Support for os/arch specific cgo files is included thanks to the standard go/build package.

With goflymake we get not only a syntax check, but a full compile and link check. Since both flymake and flycheck generate a temporary file on disk, we need to filter out the original file. For example, consider a package where we have two files, foo.go and bar.go. In order to compile and link, go build needs both files as input. However, while editing foo.go we want flymake to use flymake_foo.go and bar.go as input, excluding foo.go to avoid duplicate symbol errors.

The same filtering applies when editing test files ending in _test.go.

In addition to file filtering, goflymake dispatches to the appropriate go tool command. When editing files that end in _test.go, to go test -c. Otherwise to the go build command.

Setup

1. If needed, update your ${PATH} to include Go installed binaries, for example:

   export PATH=${PATH}:${GOPATH}/bin

   Depending on your Emacs workflow (e.g., windowing system environment), it may be required to explicitly set the following items:

   1. (setenv "GOPATH" "/path/to/gopath")
   2. (setenv "PATH" (concat (getenv "PATH") ":" "/extra/path/element"))
   3. (setq exec-path (append exec-path (list (expand-file-name "/another/thing"))))

2. Install goflymake:

   go get -u github.com/dougm/goflymake

Emacs setup

1. Install go-mode.el if you haven't already

2. Add these lines to your .emacs or similar:

• flymake

     (add-to-list 'load-path "~/gocode/src/github.com/dougm/goflymake")
     (require 'go-flymake)
  

• flycheck

     (add-to-list 'load-path "~/gocode/src/github.com/dougm/goflymake")
     (require 'go-flycheck)
  

ToDo

We probably shouldn't need the goflymake program, the go tool could be tweaked to support the flymake style of syntax checking. Maybe there is already a better way, but I couldn't find one.

Troubleshooting

The goflymake command includes forensic information to assist in debugging anomalies, which will assist you in tracking down the problem.

If worst comes to worst, the Flymake Troubleshooting Guide is definitely helpful.