[nongnu] elpa/go-mode 37f595f 365/495: cmd/guru: emacs: support running on nameless buffers

[ELPA Syncer]

branch: elpa/go-mode
commit 37f595f4d52744398ee3786cdf4e4173ac1f6150
Author: Dominik Honnef <dominik@honnef.co>
Commit: Dominik Honnef <dominik@honnef.co>

    cmd/guru: emacs: support running on nameless buffers
    
    By using guru's -modified flag and making up a file name, we can run
    guru on a buffer that has no file attached to it. This feature will only
    be useful for queries that operate on single files, as otherwise our made
    up name could cause conflicts.
    
    This will be useful for the "what" query and features using it.
    
    Change-Id: I3d199bc0548245d59ba7b492f57beb9422d7f43d
    Reviewed-on: https://go-review.googlesource.com/20431
    Reviewed-by: Alan Donovan <adonovan@google.com>
---
 guru_import/cmd/guru/go-guru.el | 45 +++++++++++++++++++++++++----------------
 1 file changed, 28 insertions(+), 17 deletions(-)

diff --git a/guru_import/cmd/guru/go-guru.el b/guru_import/cmd/guru/go-guru.el
index a7f814b..ec4fa8e 100644
--- a/guru_import/cmd/guru/go-guru.el
+++ b/guru_import/cmd/guru/go-guru.el
@@ -121,16 +121,25 @@ result."
   (with-current-buffer (go-guru--exec mode need-scope)
     (go-guru--compilation-markup)))
 
-(defun go-guru--exec (mode &optional need-scope flags)
+(defun go-guru--exec (mode &optional need-scope flags allow-unnamed)
   "Execute the Go guru in the specified MODE, passing it the
-selected region of the current buffer.  If NEED-SCOPE, prompt for
-a scope if not already set.  Return the output buffer."
-  (if (not buffer-file-name)
-      (error "Cannot use guru on a buffer without a file name"))
+selected region of the current buffer. If NEED-SCOPE, prompt for
+a scope if not already set. If ALLOW-UNNAMED is non-nil, a
+synthetic file for the unnamed buffer will be created. This
+should only be used with queries that work on single files
+only (e.g. 'what'). If ALLOW-UNNAMED is nil and the buffer has no
+associated name, an error will be signaled.
+
+Return the output buffer."
+  (or
+   buffer-file-name
+   allow-unnamed
+   (error "Cannot use guru on a buffer without a file name"))
   (and need-scope
        (string-equal "" go-guru-scope)
        (go-guru-set-scope))
-  (let* ((filename (file-truename buffer-file-name))
+  (let* ((is-unnamed (not buffer-file-name))
+        (filename (file-truename (or buffer-file-name "synthetic.go")))
          (posn (if (use-region-p)
                   (format "%s:#%d,#%d"
                           filename
@@ -142,14 +151,17 @@ a scope if not already set.  Return the output buffer."
          (env-vars (go-root-and-paths))
          (goroot-env (concat "GOROOT=" (car env-vars)))
          (gopath-env (concat "GOPATH=" (mapconcat #'identity (cdr env-vars) 
":")))
-        (output-buffer (get-buffer-create "*go-guru*")))
+         (output-buffer (get-buffer-create "*go-guru*"))
+         (buf (current-buffer)))
     (with-current-buffer output-buffer
       (setq buffer-read-only nil)
       (erase-buffer))
     (with-current-buffer (get-buffer-create "*go-guru-input*")
       (setq buffer-read-only nil)
       (erase-buffer)
-      (go-guru--insert-modified-files)
+      (if is-unnamed
+         (go-guru--insert-modified-file filename buf)
+        (go-guru--insert-modified-files))
       (let* ((args (append (list "-modified"
                                  "-scope" go-guru-scope
                                  "-tags" go-guru-build-tags)
@@ -220,15 +232,14 @@ a scope if not already set.  Return the output buffer."
   "Insert the contents of each modified Go buffer into the
 current buffer in the format specified by guru's -modified flag."
   (mapc #'(lambda (b)
-           (and (buffer-modified-p b)
-                (buffer-file-name b)
-                (string= (file-name-extension (buffer-file-name b)) "go")
-                (progn
-                  (insert (format "%s\n%d\n"
-                                  (buffer-file-name b)
-                                   (go-guru--buffer-size-bytes b)))
-                   (insert-buffer-substring b))))
-       (buffer-list)))
+            (and (buffer-modified-p b)
+                 (string= (file-name-extension (buffer-file-name b)) "go")
+                 (go-guru--insert-modified-file (buffer-file-name b) b)))
+        (buffer-list)))
+
+(defun go-guru--insert-modified-file (name buffer)
+  (insert (format "%s\n%d\n" name (go-guru--buffer-size-bytes buffer)))
+  (insert-buffer-substring buffer))
 
 (defun go-guru--buffer-size-bytes (&optional buffer)
   "Return the number of bytes in the current buffer.